akre llrf rf 2006 apr fac

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					         Linac Coherent Light Source (LCLS)

                     Low Level RF System

                 Injector Turn-on December 2006

                           April 20, 2006




April 20, 2006                                    Ron Akre, Dayle Kotturi
LCLS LLRF                 akre@slac.stanford.edu, dayle@slac.stanford.edu
   Safety First and Second and Third…..to Infinity
     Hazards in the LLRF system
          RF 1kW at 120Hz at 5uS = 0.6 Watts average,
          2 Watt average amps at 2856MHz,
          60W average amps at 476MHz
                 Hazards – RF Burns
                 Mitigation – Avoid contact with center conductor of energized
                 connectors. All employees working with LLRF systems are
                 required to have the proper training.
          110VAC Connector
                 Hazards - Shock
                 Mitigation - Don’t touch conductors when plugging into outlet.
                 All chassis are inspected by UL trained inspector.

April 20, 2006                                            Ron Akre, Dayle Kotturi
LCLS LLRF                         akre@slac.stanford.edu, dayle@slac.stanford.edu
          Scope of Work – Injector Turn-on
            Linac Sector 0 RF Upgrade WBS 1.02.04.03.01
                 All 3 RF Chassis completed and Installed
                 Control Module ready for test – John Dusatko
            Sector 20 RF distribution system WBS 1.02.04.03.02
                 Phase and Amplitude Controllers (PAC) – 6 units in Design
                 Phase and Amplitude Detectors (PAD) – 1 unit in Design
                 Phased Locked Oscillator – Use SPPS unit for Turn On
                 LO Generator – Design 90% Complete and tested
                 Multiplier – 476MHz to 2856MHz – Complete
                 4 distribution chassis - Complete
                 Laser Phase Measurement – in Design – not required for turn on
            LLRF Control and Monitor System WBS 1.02.04.03.03
                 1 kW Solid State S-Band Amplifiers – 5 units – in Fab, 2 done
                 PAD – 12 units as above in design
                 PAC – 6 units as above in design
                 Bunch Length Monitor Interface – awaiting Specs
            Beam Phase Cavity WBS 1.02.04.03.04
                 Will use single channel of PAD Chassis
                 Pill box cavity with 2 probes and 4 tuners - Complete next month


April 20, 2006                                             Ron Akre, Dayle Kotturi
LCLS LLRF                          akre@slac.stanford.edu, dayle@slac.stanford.edu
                 LCLS Layout




P. Emma



April 20, 2006                           Ron Akre, Dayle Kotturi
LCLS LLRF        akre@slac.stanford.edu, dayle@slac.stanford.edu
LLRF Control system spans Sector 20 off axis injector to beyond Sector 30
April 20, 2006                                    Ron Akre, Dayle Kotturi
LCLS LLRF                 akre@slac.stanford.edu, dayle@slac.stanford.edu
                 LCLS RF Jitter Tolerance Budget
                                                          Lowest Noise Floor
                                                          Requirement
                                                          0.5deg X-Band = 125fS
                                                          Structure Fill time = 100nS
                                     0.50
                                                          Noise floor = -111dBc/Hz
                                                          @ 11GHz 10MHz BW
                                                          -134dBc/Hz @ 476MHz

                  X-band                       X-
                                                             RMS tolerance budget for
                                                         <12% rms peak-current jitter or
                                                             <0.1% rms final e− energy
                                                           jitter. All tolerances are rms
                                                             levels and the voltage and
                                                          phase tolerances per klystron
                                                           for L2 and L3 are Nk larger,
                                                         assuming uncorrelated errors,
                                                             where Nk is the number of
                                                                 klystrons per linac.
                                                                     P. Emma
April 20, 2006                                      Ron Akre, Dayle Kotturi
LCLS LLRF                  akre@slac.stanford.edu, dayle@slac.stanford.edu
                 Slow Drift Tolerance Limits
       (Top 4 rows for De/e < 5%, bottom 4 limited by feedback dynamic range)
     Gun-Laser Timing                                               2.4* deg-S
     Bunch Charge                                                   3.2    %
     Gun RF Phase                                                   2.3 deg-S
     Gun Relative Voltage                                           0.6    %
     L0,1,X,2,3 RF Phase (approx.)                                   5   deg-S
     L0,1,X,2,3 RF Voltage (approx.)                                 5     %
    (Tolerances are peak values, not rms)                                   P. Emma, J, Wu
 * for synchronization, this tolerance might be set to 1 ps (without arrival-time measurement)

April 20, 2006                                             Ron Akre, Dayle Kotturi
LCLS LLRF                          akre@slac.stanford.edu, dayle@slac.stanford.edu
                           Linac Sector 0 RF Upgrade
LCLS must be compatible with the existing linac operation including PEP timing shifts
                                         MAIN LINAC (SECTOR 0) RF/TIMING SYSTEM
    Master Oscillator is
     located 1.3 miles
                                 1                                                                                            1.3 Miles to
                                                                                     Sum
    from LCLS Injector     476MHz                     MASTER                         Fiducial        Main Drive Line (MDL)   LCLS Injector
                           MASTER     PEP PHASE       AMPLIFIERS                     to RF           476MHz RF plus
                           OSCILLATOR SHIFTER                          476MHz                        360Hz Fiducial
Measurements on                       +-720 Degrees
                                      in 0.5mS
                                                                                                     To:
                                                                                                     Main Linac - 2 miles
January 20, 2006                                               SLC COUNTDOWN
                                                               CHASSIS 476MHz
                                                                                                     Damping Rings
                                                                                                     PEP
at Sector 21                                                   Divide to 8.5MHz                      NLCTA
                                                                                                     End Station A
                                                                                                     FFTB
show 30fS rms jitter                                                   8.5MHz                        ORION

in a bandwidth from                                         Master Trigger
                                                            Generator MTG
                                                                                        Fiducial Generator
                                                                                        Syncronized to:
                                         360Hz
10Hz to 10MHz               360Hz Line
                            Sync.
                                                            Syncs Fiducial to
                                                            8.5MHz Damping Ring
                                                                                        360Hz Power Line
                                                                                        8.5MHz Damping Ring
                                                            and 360Hz Power Line        476MHz RF Distribution




PEP PHASE SHIFT ON MAIN DRIVE LINE                                     MDL RF with TIMING Pulse – Sync to DR

April 20, 2006                                                                     Ron Akre, Dayle Kotturi
LCLS LLRF                                   akre@slac.stanford.edu, dayle@slac.stanford.edu
      Linac Sector 0 RF Upgrade Status
       New Low Noise Master Oscillator – Done
       New Low Noise PEP Phase Shifter
            RF Chassis – Done
            Control Chassis – In Test
       New Low Noise Master Amplifier – Done
       Main Drive Line Coupler in Sector 21 – Done
       Measurements
            Noise floor on 476MHz of -156dBc/Hz
            Integrated jitter from 10Hz to 10MHz of 30fS

April 20, 2006                                     Ron Akre, Dayle Kotturi
LCLS LLRF                  akre@slac.stanford.edu, dayle@slac.stanford.edu
             Sector 20 RF Distribution
                  Main Drive Line (MDL)
                  476MHz RF
                  360Hz Fiducial
                                                    LCLS Sector 20 RF Reference System                                                                            MDL to Linac Sectors 21 to 30
                  From Sector 0 (2km)                                                                                                                             PEP and Research Yard
                                                              RF HUT Coupler
                                                              476MHz Ref. 100uW
                                                              FSJ4-50 0.8dB/30ft
                                                                                                                                                         476MHz
                                                                                                                                                         LASER LOCK
                                                     LCLS 476MHz PLL                                                                                     Reference
                  TIMING SYSTEM                                                                                                                          RF CONTROL
                  FIDO                                                                                                                                   IQ Modulator
                                                            RF CONTROL
                                                            Offset adjust                                                                                                               LASER
                                  120Hz       Track/Hold
                                  TRBR        TRBR
                 119MHz                                     Sample and Hold PLL
                                                            with DAC offset adjust                                                                                                      LASER Diode
                                                            and Error Monitor                                                                                                           Output
                                                                                                   2830.5MHz LO Gen
                 119MHz Phase
                                                                                                                                                    2856MHz
                 RF MONITOR                                                                      2856MHz in                                                           IQ Modulator Control
                                                 119MHz                4x 476MHz                                                                    LASER Diode
                                                                                                                                                                      Mixer Monitor
                                                 0dBm OUT              13dBm OUT                                                                    Phase Noise
                                                                                                 IQ Modulator to adjust
                                                                                                                                                    Measurement
                                                                                                 2830.5MHz to 2856MHz Phase
                                                                                                                                                    RF MONITOR
                                                                                                 Divide 112 to 25.5MHz
                                                                                                                                                    RF CONTROL
                                                                                                 SSB Mix to 2830.5MHz
                          +13dBm in                        +13dBm in                             4X to 102MHz                                       IQ Modulator
                          476MHz to 2856MHz                476MHz to 2856MHz                                                                                                  2856MHz
                          MULTIPLIER                       MULTIPLIER                            25.5MHz out
                           +7dBm                            +7dBm
                                                                                                 102MHz out     2830.5MHz out
                                  +17dBm                            +17dBm



                                                    RF CONTROL                       RF CONTROL                          RF CONTROL                           LO Phase Monitor
                                                    IQ Modulator                     IQ Modulator                        IQ Modulator                         RF MONITOR
                                                           2856MHz                      102MHz                                  2830.5MHz
                                                           2Watt Amplifier              2Watt Amplifier                         2Watt Amplifier


                                                           Diode Detector               Diode Detector                          Diode Detector


                                                           2856MHz                        102MHz                                   2830.5MHz LO
                                                           16 Way Distribution            Digitizer Clocks                         16 Way Distribution
                                                           20dBm each                     16 Way Distribution                      20dBm each
                                                                                          20dBm each
                                                           Gun
                                                           L0A                                 Gun
                                                                                                                                     Gun
                                                                                                                                     L0A
                                                                                                                                     L0B
                                                                                                                                                                    Phase Critical Cables
                                                           L0B                                 L0A
                                                                                               L0B                                   L0TCAV
                                                           L0TCAV
                                                           L1S
                                                           L1X
                                                                                               L0TCAV
                                                                                               L1S
                                                                                                                                     L1S
                                                                                                                                     L1X                            Laser <140ft < 700fSpp
                                                           LINAC                               L1X
                                                           EXPERIMENTS                                    LO Phase Monitor
                                                                                                          RF MONITOR                                                Gun < 100ft < 400fSpp
                                2856MHz from Sector 21                                                    LO Phase Monitor
                                                                                                          RF MONITOR



April 20, 2006                                                                                                                        Ron Akre, Dayle Kotturi
LCLS LLRF                                                                    akre@slac.stanford.edu, dayle@slac.stanford.edu
          Sector 20 RF Distribution System Status
    Phase Locked Oscillator – 476MHz
         Initial Turn On use SPPS Oscillator
         May modify control to achieve better stability during 2007
    LO Generator – 2830.5MHz
         Design complete – Prototype tested – 25MHz SSB modulator board done
         2856MHz IQ Modulator prototype near completion
    Multipliers - 476MHz to 2856MHz – Done
    Phase and Amplitude Control (PAC) Unit
         In Design – IQ Modulators and Amplifiers selected – See Next Section
    Phase and Amplitude Detector (PAD) Unit
         In Design – Testing Mixers, Amplifiers, Filters – See Next Section
    Amplifiers – not ordered yet
    Laser Phase Measurement System – Design Started


April 20, 2006                                          Ron Akre, Dayle Kotturi
LCLS LLRF                       akre@slac.stanford.edu, dayle@slac.stanford.edu
                 LLRF Control System
           Distributed Control System
           Microcontroller based IOC Control and
           Detector Modules
           Ethernet Switch
           Central Feedback Computer




April 20, 2006                                Ron Akre, Dayle Kotturi
LCLS LLRF             akre@slac.stanford.edu, dayle@slac.stanford.edu
LLRF Control and Monitor System Klystron Station
                                                                                                                                            TRIG

            LCLS RF HUT                                                                                                                     ENET
            2830.5MHz LO                                             Trig & Ethernet
            Amp / Splitter
                                                                                             From Klystron Drive Coupler
            TCAV        20-5                                 3dBm    LO
            RF Gun      20-6                                                                 PAC OUT
                                                                          PAD
            L0A         20-7                                                                 KLY BEAM Voltage
            L0B         20-8

            L1S         21-1
                                                                                             SPARE

            L1X         21-2
                                                                        102MHz
                                                                     Clock In  Out
            LCLS RF HUT        240ft = 2.5dB 1/2 Superflex
            102MHz Clock
            Amp / Splitter     = 1.6dB LDF4
                               = 3dB LDF1                    23dBm
            TCAV        20-5

            RF Gun      20-6

            L0A         20-7

            L0B         20-8

            L1S         21-1

            L1X         21-2
                                                                          13dBm
                                                                      102MHz Clock In
            LCLS RF HUT                                                                               SSSB
            2856MHz RF                                                       PAC
            Amp / Splitter     240ft = 17dB 1/2 Superflex
                               = 10dB LDF4                                 Coupled Out                  Coupled Out
            TCAV        20-5                                 3dBm     In 2856MHz Out         17dBm In 2856MHz Out
                                                                                                                           To IPA
            RF Gun      20-6                                                                                               Klystron Drive
                                                                            SSSB Control           Control & TRIG
            L0A         20-7
                                                                          Trig & Ethernet
            L0B         20-8                                                                                                                ENET
            L1S         21-1
                                                                                                                                            TRIG
            L1X         21-2
                               140ft = 25dB 3/8 Superflex                       KLYSTRON STATION
           RF HUT

April 20, 2006                                                                              Ron Akre, Dayle Kotturi
LCLS LLRF                                           akre@slac.stanford.edu, dayle@slac.stanford.edu
         LLRF Control and Monitor System Status
                 1 kW Solid State S-Band Amplifiers – 5 units
                    1kW amplifier modules currently in test
                    Existing amplifier support design under review
                 Phase and Amplitude Detectors – 11 dual chan units
                    Preliminary Design Complete
                    Evaluating amplifiers, mixers, and filters
                 Phase and Amplitude Controllers – 6 single chan units
                    Preliminary design complete
                    Evaluating mixers and amplifiers
                 Bunch Length Monitor Interface
                    Need Specifications




April 20, 2006                                          Ron Akre, Dayle Kotturi
LCLS LLRF                       akre@slac.stanford.edu, dayle@slac.stanford.edu
                 Beam Phase Cavity Status
   Measurement of beam phase to RF reference phase. The result will be
   used to correct timing of laser to RF reference. Cavity is located
   between L0A and L0B.

   Electronics will use single
   channel of PAD Chassis
   Pill box cavity with 2 probes
   and 4 tuners

   Cavity Electronics will use
   single channel of RF Monitor
   Cavity in fabrication
   Complete – May 2006
   Bake – June 2006


April 20, 2006                                       Ron Akre, Dayle Kotturi
LCLS LLRF                    akre@slac.stanford.edu, dayle@slac.stanford.edu
                 Controls Engineering Requirements
     When beam is present, control will be done by
     beam-based longitudinal feedback (except for T-
     cavs); when beam is absent, control will be done
     by local phase and amplitude controller (PAC)
     Adhere to LCLS Controls Group standards:
     RTEMS, EPICS, Channel Access protocol
           Ref: Why RTEMS? Study of open source real-time OS
     Begin RF processing of high-powered structures
     June 2006

April 20, 2006                                     Ron Akre, Dayle Kotturi
LCLS LLRF                  akre@slac.stanford.edu, dayle@slac.stanford.edu
                       External Interfaces
     LLRF to LCLS global control system
           PVs available for edm screens, archiving, etc over
          controls network
     LLRF VME to beam-based longitudinal feedback
          from feedback: phase and amplitude corrections at 120
          Hz over private ethernet
          from LLRF: phase and amplitude values
     (internal) LLRF VME to LLRF microcontrollers
           from VME: triggers, corrected phase and amplitude
           from microcontrollers: phase and amplitude averaged
          values at 120 Hz, raw phase and amplitude values for
          diagnostics

April 20, 2006                                     Ron Akre, Dayle Kotturi
LCLS LLRF                  akre@slac.stanford.edu, dayle@slac.stanford.edu
                 Sector 20 PAC and PAD Control
    VME IOC
    Ethernet Switch
    Arcturus Coldfire
         13 PADs
             FIFO
             ADC
         13 PACs
             FPGA
             DAC

April 20, 2006                                    Ron Akre, Dayle Kotturi
LCLS LLRF                 akre@slac.stanford.edu, dayle@slac.stanford.edu
EPICS PANELS
 Single Pulse
 Diagnostic Panels for
 PADs are Running
 Remaining Software
      History Buffer Select
      PVs
      Multi pulse data
      analysis, correlation
      plots
      Local RF Feedback
      loops
      Links to global
      Feedback loops


April 20, 2006                                        Ron Akre, Dayle Kotturi
LCLS LLRF                     akre@slac.stanford.edu, dayle@slac.stanford.edu
                             RF Status Summary
     Linac New Low Noise Source – RF components installed, Controls Feb06
     RF Distribution – Prototyping underway (R. Akre, B.Hong, H. Schwarz)
     Monitor Controller Board (J. Gold, R. Akre, Till Straumann)
          Single channel prototype for ADS5500 tested to specifications
          Four channel ADS5500 board – layout complete (SNR 70dBFS)
          Switched to LTC2208 16bit 130MSPS ADC (Prototype in test) (SNR 77dBFS)
     RF Monitor Board in preliminary design (H. Schwarz, B.Hong)
          Testing mixers
     Control Boards (J. Olsen)
          Fast Control Board – All but slow ADCs for temp and voltages tested and low level drivers
          written
          Slow control board – use fast board
     RF Control Board in preliminary design (H. Schwarz, B. Hong)
     Software (D. Kotturi, Till Straumann)
          EPICS on RTEMS on Microcontroller done
          Drivers – data collection interrupt routine done
          Algorithms – PAD 90% complete PAC in progress
          Calibration routines – Need specifications
          Collision free Ethernet



April 20, 2006                                                   Ron Akre, Dayle Kotturi
LCLS LLRF                              akre@slac.stanford.edu, dayle@slac.stanford.edu
                      LLRF Schedule
      RF Distribution Design Complete May 2006
      RF Hut Distribution System installed August 2006
      PAC design Complete June 2006
      PAD design Complete July 2006
      PAC and PAD minimal operational software complete
      Ethernet testing with multiple PACs and PADs???
      Single S-Band station – hardware installed Sept 2006
      4 other S-Band Stations – November 2006
      Feedback software interfacing???
      Test and debug with Klystrons On – December 2006
      X-Band Station January 2007


April 20, 2006                                  Ron Akre, Dayle Kotturi
LCLS LLRF               akre@slac.stanford.edu, dayle@slac.stanford.edu
                 End of LLRF RF Talk
                  Backup for RF Talk
                    Mostly Correct




April 20, 2006                              Ron Akre, Dayle Kotturi
LCLS LLRF           akre@slac.stanford.edu, dayle@slac.stanford.edu
                 DESIGN PHILOSOPHY
     Reliability is inversely proportional to the number of
     connectors.
     Stability is inversely proportional to the number of
     connectors.
     Measurement accuracy is inversely proportional to
     the number of connectors and the amount of
     Teflon,which is typically found in connectors.
     Cost of maintenance is proportional to the number
     of connectors.

April 20, 2006                                 Ron Akre, Dayle Kotturi
LCLS LLRF              akre@slac.stanford.edu, dayle@slac.stanford.edu
                      Electro-Optical Sampling                                   Timing Jitter
200 mm thick ZnTe crystal
                                                     Single-Shot                  (20 Shots)

                                      e-                       <300 fs


                            Ti:Sapphire
                            laser

e- temporal information is encoded
on transverse profile of laser beam


                                                                                  170 fs rms


Adrian Cavalieri et al., U. Mich.
April 20, 2006                                         Ron Akre, Dayle Kotturi
LCLS LLRF                      akre@slac.stanford.edu, dayle@slac.stanford.edu
                      MPS – PPS Issues
                 Addressed by Controls Group
                     Not Reviewed Here
     Vacuum
          New vacuum system summary to be fed to each
          klystron existing MKSU.
     PPS System
          Injector modulators will be interlocked by Injector
          PPS system.
          PPS requirements for radiation from the injector
          transverse accelerator needs to be determined.
          Radiation levels will be measured during testing
          in the Klystron Test Lab – Feb 06.
April 20, 2006                                   Ron Akre, Dayle Kotturi
LCLS LLRF                akre@slac.stanford.edu, dayle@slac.stanford.edu
                 Bandwidth of S-Band System
            Upper Frequency Limit – 10MHz
                 Beam-RF interaction BW due to structure fill time
                    < 1.5MHz S-Band Accelerators and Gun
                    ~10MHz X-Band and S-Band T Cav
                 Structure RF Bandwidth ~ 16MHz
                 5045 Klystron ~ 10MHz
            Lower Frequency Limit – 10kHz
                 Fill time of SLED Cavity = 3.5uS about 100kHz
                 Laser – Needs to be measured ~ 10kHz


April 20, 2006                                       Ron Akre, Dayle Kotturi
LCLS LLRF                    akre@slac.stanford.edu, dayle@slac.stanford.edu
                            Noise Levels
    RF Reference Single Side Band (SSB) Noise Floor
          2856MHz RF Distribution -144dBc/Hz
             -174dBc/Hz @ 119MHz (24x = +28dB +2 for multiplier)
          2830.5MHz Local Oscillator -138dBc/Hz
    Integrated Noise
         -138dBc/Hz at 10MHz = -65dBc = 32fS rms
         SNR = 65dB for phase noise
    Added noise from MIXER (LO noise same as RF)
         SNR of 62dB
    ADC noise levels
         SNR of 70dB – 14bit ADS5500 at 102MSPS
April 20, 2006                                       Ron Akre, Dayle Kotturi
LCLS LLRF                    akre@slac.stanford.edu, dayle@slac.stanford.edu
                  Phase Noise – Linac Sector 0



       OLD MASTER OSCILLATOR                             NEW MASTER OSCILLATOR
       -133dBc/Hz at 476MHz                              -153dBc/Hz at 476 MHz
       340fSrms jitter in 10MHz BW                       34fSrms jitter in 10MHz BW




                                Integrated Noise - Timing Jitter fs rms
 Integral end       5MHz                                                      10kHz
 Integral start     1M     100k           10k          1k                     100       10
 Aug 17, 2004
 Sector 30          27     30             33           38                     75        82
 Jan 20, 2006
 Sector 21          15     19             20           20                     8         17


April 20, 2006                                                Ron Akre, Dayle Kotturi
LCLS LLRF                       akre@slac.stanford.edu, dayle@slac.stanford.edu
      Sector 20 RF Distribution Cable Errors
           Temperature Coefficient of 2.8ppm/ºF and
           Cable length is 1200ºS/ft
           All Cables except LASER are less than 100ft

        Distances feet and errors in degrees S total range
        RF Hut        Down       Linac          Wall         Injector Total
Unit    Ft degS ft degS          ft degS         ft degS ft degS DegS
Laser 8 0.054 25 0.017 10 0.014 10 0.007 85 0.58                         0.68
Gun     8 0.054 25 0.017 10 0.014 10 0.007 40 0.27                       0.37
L0-A    8 0.054 25 0.017 10 0.014 10 0.007 30 0.21                       0.31
B Phas 8 0.054 25 0.017 10 0.014 10 0.007 20 0.14                        0.24
L0-B    8 0.054 25 0.017 10 0.014 10 0.007 20 0.14                       0.24
L0-T    8 0.054 25 0.017 10 0.014 10 0.007 10 0.07                       0.17
L1-S    8 0.054 25 0.017 50 0.068                                        0.14
L1-X    8 0.054 25 0.017 60 0.081                                        0.16
 Temperature Variations: RF Hut ±1ºF : Penetration ±0.1ºF : Linac : ±0.2ºF
                          Shield Wall ±0.1ºF : Injector ±1ºF
April 20, 2006                                       Ron Akre, Dayle Kotturi
LCLS LLRF                    akre@slac.stanford.edu, dayle@slac.stanford.edu
               RF System Topology / Specifications
Linac
Sector 0 RF
                                      Num ber of cables per device
     MDL                              Reference cables are
                                      8ft and can drift +-50fS
                              476MHz PLL                             Cable Drift Based on
       L0, L1 - 5 Klystrons
                              2830.5MHz LO                           Temperature variations   Most Devices
       Specifications
                              Amp / Splitter          PAD            and temp co of 5ppm/degC are in tunnel
       100fS rms jitter
       +-2.3pS drift          Laser              1                          +-680fS            Laser
                                                      Laser

                              RF Gun             5    RF Gun                +-370fS            RF Gun
       L2 - 4 Sectors                            2                          +-310fS
       Specifications         L0A                     L0A                                      L0A
       70fS rm s jitter                          2                          +-240fS
                              Phase Cavity            Phase Cavity                             Phase Cavity
       +-5pS drift
                              L0B                2    L0B                   +-240fS            L0B
       L3 - 6 Sectors         L1S                4                           +-140fS
                                                      L1S                                      L1S
       Specifications
       150fS rms jitter       L1X                2                           +-160fS           L1X
                                                      L1X
       +-5pS drift
                                                 1                           +-500fS
                              L2 Ref                  L2 Ref                                   L2 Ref


                                           RF HUT
April 20, 2006                                                       Ron Akre, Dayle Kotturi
LCLS LLRF                                 akre@slac.stanford.edu, dayle@slac.stanford.edu
                 RF Monitor Signal Counts
                                   ADC Chan Cnt          Chassis Count/Location
     Distribution (5~2850MHz, 4<500MHz)       4                               1Hut
     RF Gun                                   9                     1Kly      1.5Hut
     Beam Phase Cavity                        2                               0.5Hut
     L0-A Accelerator                         4                     1Kly      0.5Hut
     L0-B Accelerator                         4                     1Kly      0.5Hut
     L0-T Transverse Accelerator              4                     1Kly      0.5Hut
     L1-S Station 21-1 B, C, and D Acc        6                     1Kly      1.0Hut
     L1-X X-Band accelerator X-Band           5                     1Kly      0.5Hut
     S25-Tcav                                 4                     1Kly
     S24-1, 2, & 3 Feedback                   0
     S29 and S30 Feedback                     0

     Total Chassis                                                  7Kly      6Hut
     Total into Hut IOC                                             12

April 20, 2006                                      Ron Akre, Dayle Kotturi
LCLS LLRF                   akre@slac.stanford.edu, dayle@slac.stanford.edu
                 RF Control Signal Counts
     Distribution (3~2850MHz, 3<500MHz)                         6 IQ Mod
     RF Gun                                                     1 Klystron
     Beam Phase Cavity                                          1 IQ mod
     L0-A Accelerator                                           1 Klystron
     L0-B Accelerator                                           1 Klystron
     L0-T Transverse Accelerator                                1 Klystron
     L1-S Station 21-1 B, C, and D accelerators                 1 Klystron
     L1-X X-Band accelerator X-Band                             1 IQ Mod
     S25-Tcav                                                   1 Klystron
     S24-1, 2, & 3 Feedback                                     3 Klystrons
     S29 and S30 Feedback                                2 IQ modulators 476MHz

     Total modulators              11 Fast      8 Slow              19 modulators
     Totals at ~2856MHz                                             14 modulators
     Total into Hut IOC                                             14 modulators

April 20, 2006                                      Ron Akre, Dayle Kotturi
LCLS LLRF                   akre@slac.stanford.edu, dayle@slac.stanford.edu
           LLRF Control and Monitor System

      LLRF Control and Monitor System
          1 kW Solid State S-Band Amplifiers – 5 units
          Phase and Amplitude Monitors – 12 units
          Phase and Amplitude Controllers – 6 units
          Bunch Length Monitor Interface – Need Specifications




April 20, 2006                                   Ron Akre, Dayle Kotturi
LCLS LLRF                akre@slac.stanford.edu, dayle@slac.stanford.edu
                                    RF Control
 Required 13 Units
                                                                    I Control




                                         3
 Includes Distribution
                           1
                                          I                        BXMP1007
 RF In                         LO                    RF 2
17dBm                                                                                    RF Out
                                                            0dBm                         17dBm
                                          Q


                                                                    Q Control
                                         4
                 2856MHz Input Monitor              2856MHz Output Monitor

                                     2850MHz IQ Modulator
 RF Control Module consist of the following:
 Input Coupler, IQ Modulator, Amplifier, Output Coupler
 Filters for I and Q inputs
April 20, 2006                                                 Ron Akre, Dayle Kotturi
LCLS LLRF                              akre@slac.stanford.edu, dayle@slac.stanford.edu
                                          RF Monitor
      Required 13 Chassis for Injector – Includes Distribution
      LO 2830.5MHz : RF 2856MHz
      IF 25.5MHz (8.5MHz x 3 in sync with timing fiducial)
      Double-Balanced Mixer
      Mixer IF to Amp and then Low Pass Filter
      Filter output to ADC sampling at 102MSPS

    2830.5MHz Local Osc.
                              Amplifier
                                                                      To ADC
                 RF LO




                         IF
                                                                      LTC2208 SNR = 77dBFS
                     MIXER                  25.5MHz BP FILTER
                                                                      102MSPS
    2856MHz RF Signal


April 20, 2006                                                    Ron Akre, Dayle Kotturi
LCLS LLRF                                 akre@slac.stanford.edu, dayle@slac.stanford.edu
         1 kW Solid State S-Band Amplifiers

                                                   Design Complete
                                                   Two Units on the Shelf
                                                   Modules in house – and
                                                   tested
                                                   Support parts – Some
                                                   parts in house
                                                        Power Supplies, relays,
                                                        chassis on order




April 20, 2006                              Ron Akre, Dayle Kotturi
LCLS LLRF           akre@slac.stanford.edu, dayle@slac.stanford.edu
                 SLAC Linac RF – New Control
                         MDL 476MHz
                                           Next Sector       The new control system will tie in
                                 1mW
                        1W                                   to the IPA Chassis with 1kW of
                                 6X
                                 2856MHz                     drive power available. Reference
      Existing
      Phase                                                  will be from the existing phase
      Reference                   SubBooster
      Line                                                   reference line or the injector new
                                   Sub Drive Line
                                                             RF reference




                                                                                          3
             To Next                                                                      I
             Klystron               3kW                                                                   1
                                                                               2 RF                  LO




                                           IPA                     1kW Amp                Q




                                                                                          4
                                                                   2856MHz
         20mW                          High Power                                     IQ Modulator
                                       Phase Shifter
                                       Attenuator
                                                             I and Q will be controlled with a
      Phase &
      Amplitude                        Klystron
                                                             16bit DAC running at 119MHz.
      Detector
                                       SLED
                                                             Waveforms to the DAC will be set
                                    200MW
                                                             in an FPGA through a
                         -45dB                               microcontroller running EPICS on
 Existing
 System                             Accelerator              RTEMS.

April 20, 2006                                                     Ron Akre, Dayle Kotturi
LCLS LLRF                                  akre@slac.stanford.edu, dayle@slac.stanford.edu
                 Controls Talk




April 20, 2006                            Ron Akre, Dayle Kotturi
LCLS LLRF         akre@slac.stanford.edu, dayle@slac.stanford.edu
                               LLRF Controls

     Outline
          Requirements
          External Interfaces
          Schedule
                 Date Needed
                 Prototype Completion Date
                 Hardware Order Date
                 Installation
                 Test Period
          Design
                 Design Maturity (what reviews have been had)
                 State of Wiring Information
                 State of Prototype

April 20, 2006                                          Ron Akre, Dayle Kotturi
LCLS LLRF                       akre@slac.stanford.edu, dayle@slac.stanford.edu
                        Requirements
     At 120 Hz, meet phase/amp noise levels
     defined as:
           0.1% rms amplitude
           100 fs rms in S-band (fill time = 850 ns)
           125 fs rms in X-band (fill time = 100 ns)
          All tolerances are rms levels and the voltage and
          phase tolerances per klystron for L2 and L3 are
          Nk larger, assuming uncorrelated errors, where
          Nk is the number of klystrons per linac (L2 has
          28; L3 has 48)
April 20, 2006                                  Ron Akre, Dayle Kotturi
LCLS LLRF               akre@slac.stanford.edu, dayle@slac.stanford.edu
                  Engineering Requirements
     When beam is present, control will be done by
     beam-based longitudinal feedback (except for T-
     cavs); when beam is absent, control will be done
     by local phase and amplitude controller (PAC)
     Adhere to LCLS Controls Group standards:
     RTEMS, EPICS, Channel Access protocol
           Ref: Why RTEMS? Study of open source real-time OS
     Begin RF processing of high-powered structures
     May 20, 2006

April 20, 2006                                   Ron Akre, Dayle Kotturi
LCLS LLRF                akre@slac.stanford.edu, dayle@slac.stanford.edu
                       External Interfaces
     LLRF to LCLS global control system
           PVs available for edm screens, archiving, etc over
          controls network
     LLRF VME to beam-based longitudinal feedback
          from feedback: phase and amplitude corrections at 120
          Hz over private ethernet
          from LLRF: phase and amplitude values
     (internal) LLRF VME to LLRF microcontrollers
           from VME: triggers, corrected phase and amplitude
           from microcontrollers: phase and amplitude averaged
          values at 120 Hz, raw phase and amplitude values for
          debug

April 20, 2006                                     Ron Akre, Dayle Kotturi
LCLS LLRF                  akre@slac.stanford.edu, dayle@slac.stanford.edu
                                                                                                            External Interfaces: Laser - Tcav
                                                                                         RF Phase and Amplitude correction at 120 Hz for:
                                                                                              laser, gun, L0-A, L0-B, L1-S, L1-X, T cav
                                                                                        In-house modules sharing VME crate for timing triggers
                                                                                          Temperature monitors



                                                                                    RF Reference/4 = 119 MHz                                            T Cav
 476 MHz RF Reference clock distributed to all 30 sectors in the Linac and beyond




                                                                                    stabilized to 50 fs jitter                                        L1-X
                                                                                                                                                    L1-S
                                                                                                                                                 L0-B
                                                                                                                                              L0-A
                                                                                                                                             gun
                                                                                                                              Laser and RF ref
                                                                                                 PAD
                                                                                                                                       D
                                                                                                                          Coldfire     A
                                                                                                                     F
                                                                                                 I and Q                    CPU        C
                                                                                                              A      I
                                                                                                 Demo-                    running
                                                                                                              D      F
                                                                                                 dulator
                                                                                                              C      O
                                                                                                                          RTEMS        s                                                                                      VME Crate at S20
                                                                                                                            and        l
                                                                                                                     s
                                                                                                                           EPICS       o                                                   C               E
                                                                                                                                                                                                                                   running
                                                                                                                                       w                                                   P               V                    longitudinal,
                                                                                    RF Reference*6 = 2856 MHz                                                                              U               R
                                                                                    stabilized to 50 fs jitter                                                                                                                  beam-based
                                                                                                PAC
                                                                                                                                                                                                                                  feedback
                                                                                                                                  D
                                                                                                 Coldfire                         A
                                                                                                   CPU                            C                                                                              1 trigger
                                                                                                                             D
                                                                                                 running                                                                                                           for 4
                                                                                                                  FPGA       A
                                                                                                 RTEMS                            s                                                                              channels
                                                                                                                             C
                                                                                                   and                            l                                                                                of 1k
                                                                                                  EPICS                           o                                                                              samples
                                                                                                                                  w

                                                                                                      Private ethernet                       Private ethernet                                                               Private ethernet
                                                                                                     4 kBytes at 120 Hz                     8 kBytes at 120 Hz

                                                                                                                                                                                                      Controls gigabit ethernet (interface to MCC)

                                                                                                                                                          IQ Modulator
                                                                                                                                                           gives phase
                                                                                                                                                          and amplitude
                                                                                                                                                              control
                                                                                                                          1 trigger to travel
                                                                                                                           up to ½ sector
                                                                                                                                 away                               100 mW
                                                                                                  Lin
                                                                                                      ac
                                                                                                        /A




                                                                                                                                                                     All except laser RF
                                                                                                           cc
                                                                                                              ele
                                                                                                              La r RF
                                                                                                La

                                                                                                                 se 1




                                                                                                                                                                                                                  119 MHz
                                                                                                                  rat
                                                                                                                    se




                                                                                                                                                    Solid State Sub Booster                                        Laser
                                                                                                                     r R 19




                                                                                                                      or




                                                                                                                                                                                                                  Oscillator
                                                                                                                         F 1 MH




                                                                                                                         RF ler
                                                                                                                          Li z (I& Q)
                                                                                                                            na




                                                                                                                                                                     1 kW
                                                                                                                             20 z




                                                                                                                             Ou ato
                                                                                                                               c/




                                                                                                                                                                                                               photodiode
                                                                                                                                 A
                                                                                                                                  H (I&




                                                                                                                                                                                                                                          Amps
                                                                                                                                  t (I r R
                                                                                                                                   cc




                                                                                                                                                                Klystron
                                                                                                                                      e


                                                                                                                                      &Q F




                                                                                                                                                                                                                   119 MHz
                                                                                                                                                                                                                                               120 Hz
                                                                                                                                        ) I
                                                                                                                                        Q)




                                                                                                                                                                      60 MW
                                                                                                                                                                                                           photodiode
                                                                                                                                                                                                                                  UV
                                                                                                                                                                                                                                           Gun
                                                                                                                                                                 SLED
                                                                                                                                                n




                                                                                                                                                                                  NB: For the gun, SLED
                                                                                                                                                                 cavity
                                                                                                                                                  (I




                                                                                                                                                                                   cavity is shorted out
                                                                                                                                                    &
                                                                                                                                                      Q
                                                                                                                                                        )




                                                                                                                                                                     HPRF
                                                                                                                                                                    240 MW

                                                                                                                                                          1 kW                          1 kW

                                                                                                                                                                          60 MW



                                                                                                                                                                      10' accelerator


April 20, 2006                                                                                                                                                                                   Ron Akre, Dayle Kotturi
LCLS LLRF                                                                                                                                    akre@slac.stanford.edu, dayle@slac.stanford.edu
                                                                                                                     External Interfaces: L2-L3
                                                                                          RF Phase and Amplitude correction at 120 Hz for:
                                                                                               laser, gun, L0-A, L0-B, L1-S, L1-X, T cav
                                                                                         In-house modules sharing VME crate for timing triggers
                                                                                           Temperature monitors



                                                                                     RF Reference/4 = 119 MHz                                            T Cav
  476 MHz RF Reference clock distributed to all 30 sectors in the Linac and beyond




                                                                                     stabilized to 50 fs jitter                                        L1-X
                                                                                                                                                     L1-S
                                                                                                                                                  L0-B
                                                                                                                                               L0-A
                                                                                                                                              gun
                                                                                                                               Laser and RF ref
                                                                                                  PAD
                                                                                                                                        D
                                                                                                                           Coldfire     A
                                                                                                                      F
                                                                                                  I and Q                    CPU        C
                                                                                                               A      I
                                                                                                  Demo-                    running
                                                                                                               D      F
                                                                                                  dulator
                                                                                                               C      O
                                                                                                                           RTEMS        s                                                                                      VME Crate at S20
                                                                                                                             and        l
                                                                                                                      s
                                                                                                                            EPICS       o                                                   C               E
                                                                                                                                                                                                                                    running
                                                                                                                                        w                                                   P               V                    longitudinal,
                                                                                     RF Reference*6 = 2856 MHz                                                                              U               R
                                                                                     stabilized to 50 fs jitter                                                                                                                  beam-based
                                                                                                 PAC
                                                                                                                                                                                                                                   feedback
                                                                                                                                   D
                                                                                                  Coldfire                         A
                                                                                                    CPU                            C                                                                              1 trigger
                                                                                                                              D
                                                                                                  running                                                                                                           for 4
                                                                                                                   FPGA       A
                                                                                                  RTEMS                            s                                                                              channels
                                                                                                                              C
                                                                                                    and                            l                                                                                of 1k
                                                                                                   EPICS                           o                                                                              samples
                                                                                                                                   w

                                                                                                       Private ethernet                       Private ethernet                                                               Private ethernet
                                                                                                      4 kBytes at 120 Hz                     8 kBytes at 120 Hz

                                                                                                                                                                                                       Controls gigabit ethernet (interface to MCC)

                                                                                                                                                           IQ Modulator
                                                                                                                                                            gives phase
                                                                                                                                                           and amplitude
                                                                                                                                                               control
                                                                                                                           1 trigger to travel
                                                                                                                            up to ½ sector
                                                                                                                                  away                               100 mW
                                                                                                   Lin
                                                                                                       ac
                                                                                                         /A




                                                                                                                                                                      All except laser RF
                                                                                                            cc
                                                                                                               ele
                                                                                                               La r RF
                                                                                                 La

                                                                                                                  se 1




                                                                                                                                                                                                                   119 MHz
                                                                                                                   rat
                                                                                                                     se




                                                                                                                                                     Solid State Sub Booster                                        Laser
                                                                                                                      r R 19




                                                                                                                       or




                                                                                                                                                                                                                   Oscillator
                                                                                                                          F 1 MH




                                                                                                                          RF ler
                                                                                                                           Li z (I& Q)
                                                                                                                             na




                                                                                                                                                                      1 kW
                                                                                                                              20 z




                                                                                                                              Ou ato
                                                                                                                                c/




                                                                                                                                                                                                                photodiode
                                                                                                                                  A
                                                                                                                                   H (I&




                                                                                                                                                                                                                                           Amps
                                                                                                                                   t (I r R
                                                                                                                                    cc




                                                                                                                                                                 Klystron
                                                                                                                                       e


                                                                                                                                       &Q F




                                                                                                                                                                                                                    119 MHz
                                                                                                                                                                                                                                                120 Hz
                                                                                                                                         ) I
                                                                                                                                         Q)




                                                                                                                                                                       60 MW
                                                                                                                                                                                                            photodiode
                                                                                                                                                                                                                                   UV
                                                                                                                                                                                                                                            Gun
                                                                                                                                                                  SLED
                                                                                                                                                 n




                                                                                                                                                                                   NB: For the gun, SLED
                                                                                                                                                                  cavity
                                                                                                                                                   (I




                                                                                                                                                                                    cavity is shorted out
                                                                                                                                                     &
                                                                                                                                                       Q
                                                                                                                                                         )




                                                                                                                                                                      HPRF
                                                                                                                                                                     240 MW

                                                                                                                                                           1 kW                          1 kW

                                                                                                                                                                           60 MW



                                                                                                                                                                       10' accelerator



April 20, 2006                                                                                                                                                                                   Ron Akre, Dayle Kotturi
LCLS LLRF                                                                                                                                   akre@slac.stanford.edu, dayle@slac.stanford.edu
                                                Design
     Design maturity (what reviews have been had):
          RF/Timing Design, DOE Review, August 11, 2004
          Akre_FAC_Oct04_RF_Timing, FAC Review, October, 2004
          Low Level RF Controls Design, LCLS Week, January 25-27, 2005
          Low Level RF, Lehman Review, May 10-12, 2005
          LLRF Plans for Development and Testing of Controls, LCLS Week, July 21, 2005
          Low Level RF Design, Presentation for Controls Group, Sept. 13, 2005
          LLRF Preliminary Design review, SLAC, September 26, 2005
          LCLS LLRF Control System - Kotturi, LLRF Workshop, CERN, October 10-13, 2005
          LCLS LLRF System - Hong, LLRF Workshop, CERN, October 10-13, 2005
          LLRF and Beam-based Longitudinal Feedback Readiness - Kotturi/Akre, LCLS Week, SLAC, October 24-26,
          2005
          LCLS Week LLRF and feedback - Kotturi/Allison, LCLS Week, SLAC, October 24-26, 2005
          LLRF, LCLS System Concept Review/Preliminary Design Review, SLAC, November 16-17, 2005 Comments
          LLRF Beam Phase Cavity Preliminary Design review, SLAC, November 30, 2005
      Docs at: http://www.slac.stanford.edu/grp/lcls/controls/global/subsystems/llrf
     State of wiring: percent complete Captar input will be given at time of presentation
     State of prototype: PAD (1 chan ADC) and PAC boards built (shown on next pages).Testing.




April 20, 2006                                                       Ron Akre, Dayle Kotturi
LCLS LLRF                                akre@slac.stanford.edu, dayle@slac.stanford.edu
                 PAD – the monitor board




April 20, 2006                                    Ron Akre, Dayle Kotturi
LCLS LLRF                 akre@slac.stanford.edu, dayle@slac.stanford.edu
                                         PAD – the monitor board

               RF Board                        2 X 16 bit ADC                          Control Board
                                               119 or 102MHz Clock
                              Line Drivers     LTC2208
                              Filters          Transformer Coupled Inputs       FIFO 2 X 1k words
                                                                   16bit DATA                          16 bit
                 25.5MHz IF
                                                  Chan. 1                                              DATA
                                                                     WCLK
                    IF




 RF CHAN 1        RF LO
                                                                                                                CONTROL /
 INPUT                                                             16bit DATA                                   Arcturus uC5282




                                                                                                                                         ETHERNET
                 MIXER                                                                                  CS/
                                                  Chan. 2                                               CLK     Microcontroller Module
                                                                     WCLK                                       with 10/100 Ethernet
                    IF




 RF CHAN 2        RF LO
 INPUT
                 MIXER

                                                                                        Control




             LO INPUT                                                               CPLD
             RF - 25.5MHz                    EXTERNAL                                               EXTERNAL
                                             CLOCK                                                  TRIGGER
                                             102MHz                                                 120Hz




April 20, 2006                                                                    Ron Akre, Dayle Kotturi
LCLS LLRF                                     akre@slac.stanford.edu, dayle@slac.stanford.edu
                 PAC – the control board




April 20, 2006                                   Ron Akre, Dayle Kotturi
LCLS LLRF                akre@slac.stanford.edu, dayle@slac.stanford.edu
                                                       PAC – the control board
                                                                                                                    EXTERNAL
                                                                                      CLOCK             TRIGGER     TRIGGER
                                                                                                                                               SSSB
                                                                                                        Monitor TTL 120Hz
                                                                                      119MHz
                                                                                                                    60nS NIM
                                                                                                                                               Chassis
                                                                MONITOR
                                                                PORTS

                                                                                                                                                    Temperature Monitor
                                                                                                                                                    Forward Power 0-?V
             RF BOARD                                                                                                             SSSB
                                                                                                                                  Trig
                                                                                                                                                    Reflected Power 0-?V
                                                                                                                                                    Over Temp 0 or 12V
                                                 MATCHING                                                                         TTL               Power Supplie +12V
                                                                                                                                                    Power Supply -12V
                                                 FILTER                                                                           17 to 30uS
                                                 NETWORK
                        I&Q MODULATOR                                                           16bit DATA                        16 bit
                              3




                                                                                  I                                               DATA
                              I                                                MAX5875              CLK        XILINX                      CONTROL /
     RF OUTPUT   2 RF                   LO
                                             1
                                                                               2 X 16 bit DAC                  SPARTAN 3                   Arcturus uC5282
     To SSSB                                                                   119MHz Clock                    FPGA                        Microcontroller Module
                                                                                                16bit DATA




                                                                                                                                                                      ETHERNET
                                                                               (1MHz to 200MHz)                                    CS/
                              Q
                                                                                                                                   CLK     with 10/100 Ethernet
                                                                                  Q                 CLK
                              4




                                                                 AD8099 Diff Amp
      2856MHz Ref
                                                                                                     Control            Control



                                                                                             DC Power
                                    Temperature                                              Supply               Temperature
                                    Monitor        t                                         Monitors             Monitor         t

                                                                                                                                               Thermocouples

                         DC Power
                         Supplies                                         ADCs
                                                                                                         Control Board

April 20, 2006                                                                                       Ron Akre, Dayle Kotturi
LCLS LLRF                                                   akre@slac.stanford.edu, dayle@slac.stanford.edu
                  Additional Slides

     The following two pages show an overview
     of the LLRF control modules. From these
     diagrams, counts of module types, as well as
     function and location are seen.




April 20, 2006                             Ron Akre, Dayle Kotturi
LCLS LLRF          akre@slac.stanford.edu, dayle@slac.stanford.edu
                 Overview of LLRF at Sector 20
                   RF phase and amplitude correction and global feedback at 120 Hz for LCLS LINAC S20

                                                      RF Dist’n                         Key:
                                                                            Indicates located in RF Hut
                                                          SPAC                 Otherwise at Klystron

                                                          SPAC              Indicates may be needed
                                                          SPAC
                                           Laser                            The maybe is included in
                                                          SPAC                   counts below
                                           SPAC           SPAC
                                     Gun    PAD             PAD
                                                            PAC
                                     PAC
                                     PAD
                                     PAD
                           L0-A
                           PAC       PAD
                           PAD       PAD
                           PAD
                  L0-B
                   PAC
                   PAD
                   PAD                                                                            VME Crate at S20
                 L0-Tcav                                             Eth
                                                                            C   E                      running
                                                                            P   V
                   PAC                                              recvr
                                                                            U   R
                                                                                                    longitudinal,
                   PAD
                   PAD
                                                                                                    beam-based
                            PAC
                                                                                                      feedback.
                            PAD
                            PAD
                            PAD      PAC           L1-X
                                     PAD           PAC
                           L1-S                    PAD
                                  Beam Phase       PAD
                                    Monitor        PAD

                                                                                                 S20
                                                              Fast PACs:                            8
                                                              Slow PACs (SPACs):                    6
                                                              PADs:                                 19
                                                              VME crates:                           1

April 20, 2006                                                                             Ron Akre, Dayle Kotturi
LCLS LLRF                                   akre@slac.stanford.edu, dayle@slac.stanford.edu
                         Overview of LLRF at Sector 24
      RF phase and amplitude correction and global feedback at 120 Hz for LCLS LINAC S20

                                                                               S24
                                          Fast PACs:                            4
                                          Slow PACs (SPACs):                    2
                  L24-1                   PADs:                                 2
                   PAC                    VME crates:                           1

                  L24-2
                   PAC


                  L24-3                                                 VME Crate at S24
                   PAC
                                                         C   E
                                                                             running
                                                  Eth
                 Tcav L24-8
                                                 recvr
                                                         P   V            longitudinal,
                   PAC                                   U   R
                                                                          beam-based
                   PAD
                   PAD                                                      feedback.
                   S29
                   SPAC

                      S30
                      SPAC


April 20, 2006                                                   Ron Akre, Dayle Kotturi
LCLS LLRF                         akre@slac.stanford.edu, dayle@slac.stanford.edu
          Beam Phase Monitor
                        R. Akre
                        A. Haase
                        B. Hong
                        D. Kotturi
                        V. Pacak
                        H. Schwarz

                 Preliminary Design Review
                    November 30, 2005
April 20, 2006                                Ron Akre, Dayle Kotturi
LCLS LLRF             akre@slac.stanford.edu, dayle@slac.stanford.edu
                                       Outline
                 •Purpose
                 •Specifications
                 •System outline
                 •Cavity
                 •Noise Levels
                 •Analysis
                 •Long Term Drifts
                 •Summary
April 20, 2006                                             Ron Akre, Dayle Kotturi
LCLS LLRF                          akre@slac.stanford.edu, dayle@slac.stanford.edu
  L INAC M DL R ef.
                    Laser Timing Stabilization Feedback
                                                                                                        GU N R F F EEDB AC K

                                                    2856M Hz                                            In pu ts
                                                    R F R EF .                                          GU N-C ELL 1-PH AS/AMPL
    L CL S R F
    Osci lla tor                                                                                        GU N-C ELL 2-PH AS/AMPL
                                                    L ASER
    2856M H z R ef                                                                                      Actu ator s
                                                                                                        GU N R F AC T UAT OR S
    PH ASE                                          GU N                                                                                     PH AS      AM PL
    ER RO R

                                                    L 0A                                                             GU N R F R EF.

                               Ac tu ator
  PH ASE E RR OR               L0, L 1 t o L2, L3   L 0B                                                                                      GU N R F
  B etween                     Phas e                                                  L ASER OSC IL LAT OR PH ASE                            AC TU AT ORS
  L 0, L 1 a nd L 2, L 3                                                               an d L ASER P OW ER
                                                    L 0-TC AV1                         F EED B ACK

                                                                                       In pu ts
                                                    L 1-X                              L ASER OSC . P H ASE                                      K LYST R ON
                                                                                       B UN CH C H ARGE                                          AMPL IFI ER /
      L ASER OSC IL LAT OR PH ASE                                                                                                                SLC C ON T ROL
                                                                                       GU N-C ELL 1-AMPL /PH AS
      F EED B ACK                                   L 1-S                                                                                                              GU N-F OR
                                                                                       GU N-C ELL 2-AMPL /PH AS
                                                                                       L ASER PH ASE & AM PLIT U DE
      In pu ts                                                                         GU N R F AC T UAT OR S
      B EAM PH ASE C AVIT Y                                                            B EAM PH ASE C AVIT Y

      Actu ator s                                                                      Actu ator s
      L ASER PH ASE AC T UAT OR                                                        L ASER POW ER
                                                                                                                                                                                            T OROI D
                                                                                       L ASER PH ASE AC T UAT OR

                                                                                                                                                                       RF GUN
                               PH AS       AM PL
                                                    L ASER OSC
                                                                   OU T                   LASER
   L ASER R F R EF.
                                                    R ef erenc e                          AMPLIFIER                                                                       W ATER T EMP

                                                                                                                                          L ASER
                                                                                                                                          POW ER                       GU N T U N E
                                                                                                                                          AC TU AT OR                  F EED B ACK
                           L ASER PH ASE
                                                                                                                                                                       In pu ts
                           AC TU AT OR
                                                                                                                                                                       GU N-F OR -PHAS
                                                                                                                                                 GU N-C ELL 1          GU N-C ELL 1-PH AS              B EAM
                                                                                                                                                                                                       PH ASE
                                                                          L ASER OSC . P H ASE                          L ASER PH ASE &                                GU N-C ELL 2-PH AS
                                                                                                                                                        GU N-C ELL 2                        B UN CH    C AVITY
                                                                                                                        AMPL IT UD E?
                                                                                                                                                                       Actu ator s          C HAR GE
                                                                                                                                                                       W ATER T EMP



Beam timing information from the beam phase monitor will be
used to apply corrections to the timing of the laser on the RF Gun.
April 20, 2006                                                                                                                                  Ron Akre, Dayle Kotturi
LCLS LLRF                                                                         akre@slac.stanford.edu, dayle@slac.stanford.edu
                         Specifications


          Short term (2 second) timing jitter: 100fS rms
          Long term (4 day) timing jitter: ±1pS
          Range of the above accuracies is ±10pS
          Data available at 120Hz




April 20, 2006                                     Ron Akre, Dayle Kotturi
LCLS LLRF                  akre@slac.stanford.edu, dayle@slac.stanford.edu
                 System Outline




April 20, 2006                             Ron Akre, Dayle Kotturi
LCLS LLRF          akre@slac.stanford.edu, dayle@slac.stanford.edu
                      Cavity


                 Frequency = 2856MHz
                 Q = 6000
                 Time Constant = 700nS
                 Temperature Coefficient = 50kH/°C




April 20, 2006                                 Ron Akre, Dayle Kotturi
LCLS LLRF              akre@slac.stanford.edu, dayle@slac.stanford.edu
             System Critical Noise Levels and
                      Bandwidths

           Cavity Signal – Bandwidth 500kHz
           Local Oscillator – Noise Floor –143dBc/Hz
           IF Filter – Bandwidth 4MHz
           ADC – SNR at input 76dB




April 20, 2006                                     Ron Akre, Dayle Kotturi
LCLS LLRF                  akre@slac.stanford.edu, dayle@slac.stanford.edu
             System Critical Noise Levels and Bandwidths

                                                                                                                                   Filter - Butterworth
   Beam Phase Cavity             Attenuator                                                                                        3rd order BandPass
                                                 Monitor Port                                                                      2.5.5MHz Center
            30dBm pk                                                                                                               4.0MHz BW
                                                                                                                                   2dB IL at 25.5MHz



                                      Coupler   Attenuator
            30dBm pk       23dBm pk
                                                                 3dBm pk                                                           ADC SNR 77dBFS
       -174dBm/Hz
                                                                 -174dBm/Hz            Amp
     In Tunnel                                               LO RF                                                                   ADC LTC2208
                                 Monitor Port   MIXER                IF                                                              2.25Vpp FS
                                                                            -3dBm pk                                                 Transformer coupled
                                                                                              17dBm pk             2Vpp 10dBm pk
                                                                          -146dBm/Hz                                                 102MHz Clock
               Generated from 119MHz Oscillator                                              -129dBm/Hz           Within filters BW
               Expected SSB Phase Noise Levels                            -143dBc/Hz
               Offset Hz dBc/Hz @ 2830.5MHz
                                                                                             -143dBc/Hz           -135dBm/Hz
                                                                 13dBm
               10          -82                                                                                    -143dBc/Hz
               100         -96                                            -130dBm/Hz                              Beyond 5MHz from CF
               1k          -124                                           -143dBc/Hz                              <-155dBm/Hz
               10k         -144
               20k         -146                                                                                   <-163dBc/Hz
                 1                                                                                                Integrated Noise
                     2830.5MHz Oscillator                                                                         -77dBc




April 20, 2006                                                                                           Ron Akre, Dayle Kotturi
LCLS LLRF                                                     akre@slac.stanford.edu, dayle@slac.stanford.edu
      ADC Linear
 Technologies LTC2208
     16Bit 130MHz




April 20, 2006                                   Ron Akre, Dayle Kotturi
LCLS LLRF  SNR 77.6dBFS 30MHz in Clock 130MHz SFDR 95dB
                          akre@slac.stanford.edu, dayle@slac.stanford.edu
                              Analysis
                 Phase




                                     Time




       Calculated        Measured                               Measured
       Beam Phase at     Data                                   Data
       Beam Time         Point 1                                Point 2
April 20, 2006                                     Ron Akre, Dayle Kotturi
LCLS LLRF                  akre@slac.stanford.edu, dayle@slac.stanford.edu
                                                        I & Q from Waveform
                                               Digital Down Mixing and Normalization
                                               25.5MHz Digitized Signal
                                 1

                                0.8
                                                                                        Digitized
                                0.6
                                                                                        Input Signal
      Fraction ADC Full Scale




                                0.4

                                0.2

                                 0

                                0.2

                                0.4
                                                                               .
                                0.6
                                      0   10    20      30          40    50       60
                                                     Point Number




April 20, 2006                                                                                   Ron Akre, Dayle Kotturi
LCLS LLRF                                                                akre@slac.stanford.edu, dayle@slac.stanford.edu
                            Optimization




                 Optimal Points to use for analysis is 16
                 point average at points 18 and 120
April 20, 2006                                       Ron Akre, Dayle Kotturi
LCLS LLRF                    akre@slac.stanford.edu, dayle@slac.stanford.edu
                        Analysis Results

        Standard deviation of result = 1.1e-4 or 6.3fS rms jitter
        Signal level 20dB lower will give 63fS rms jitter
        Sensitivity to frequency change = 0.6fS/2.8kH freq change
        Sensitivity to timing change over +-10deg = 1:1




April 20, 2006                                      Ron Akre, Dayle Kotturi
LCLS LLRF                   akre@slac.stanford.edu, dayle@slac.stanford.edu
                  Long Term Drifts




        80ft (1M deg) of ½ inch superflex has TC of 4ppm/degC
        Water temp tolerance is +-0.1degF = +-400fS drift
April 20, 2006                                    Ron Akre, Dayle Kotturi
LCLS LLRF                 akre@slac.stanford.edu, dayle@slac.stanford.edu
                            Summary

   Short term (2 second) timing jitter: 100fS rms
         63fS rms
   Long term (4 day) timing jitter: ±1pS
         ±0.8pS
   Range of the above accuracies is ±10pS
         Results
   Data available at 120Hz
         Simple algorithm in integer arithmetic will allow this
April 20, 2006                                     Ron Akre, Dayle Kotturi
LCLS LLRF                  akre@slac.stanford.edu, dayle@slac.stanford.edu
                 Feedback Page 1
                                            LOCAL FEEDBACK




                                  LOCAL FEEDBACK

April 20, 2006                             Ron Akre, Dayle Kotturi
LCLS LLRF          akre@slac.stanford.edu, dayle@slac.stanford.edu
                                                           GLOBAL FEEDBACK
                 Feedback Page 2
                         LOCAL FEEDBACK




April 20, 2006                             Ron Akre, Dayle Kotturi
LCLS LLRF          akre@slac.stanford.edu, dayle@slac.stanford.edu
                       Feedback Page 3                             GLOBAL FEEDBACK
                 LOCAL FEEDBACK

                                               LOCAL FEEDBACK




April 20, 2006                                     Ron Akre, Dayle Kotturi
LCLS LLRF                  akre@slac.stanford.edu, dayle@slac.stanford.edu
                                                         GLOBAL FEEDBACK
                 Feedback Page 4




April 20, 2006                             Ron Akre, Dayle Kotturi
LCLS LLRF          akre@slac.stanford.edu, dayle@slac.stanford.edu
                 Feedback Page 5
                                              GLOBAL FEEDBACK




April 20, 2006                             Ron Akre, Dayle Kotturi
LCLS LLRF          akre@slac.stanford.edu, dayle@slac.stanford.edu
                   Feedback Page 6




April 20, 2006                           Ron Akre, Dayle Kotturi
LCLS LLRF        akre@slac.stanford.edu, dayle@slac.stanford.edu

				
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