The LARP Collimation Program by markpaulgosselar

VIEWS: 35 PAGES: 69

									US LHC Accelerator Research Program
      BNL - FNAL- LBNL - SLAC




 The LARP Collimation Program




                                 05 June 2007
                    LARP DOE Review - Fermilab
                          Tom Markiewicz/SLAC
                     Four LARP Collimation Program Tasks:
               Address Efficiency, Reliability and Design of Phase I &
                    Prototype a possible solution for Phase II
    Use RHIC data to benchmark the code used to predict the cleaning efficiency of
      the LHC collimation system and develop and test algorithms for setting
      collimator gaps that can be applied at the LHC
    Responsible: Angelika Drees, BNL                    TASK ENDS FY07

    Understand and improve the design of the tertiary collimation system that
      protects the LHC final focusing magnets and experiments
    Responsible: Nikolai Mokhov, FNAL                      TASK ENDS FY07

    Study, design, prototype and test collimators that can be dropped into 32
       reserved lattice locations as a part of the “Phase II Collimation Upgrade”
       required if the LHC is to reach its nominal 1E34 luminosity
    Responsible: Tom Markiewicz, SLAC

    Use the facilities and expertise available at BNL to irradiate and then measure
      the properties of the materials that will be used for phase 1 and phase 2
      collimator jaws
    Responsible: Nick Simos, BNL                             TASK ENDS FY07
LARP DOE Review - 05 June 2007          Slide n° 2 / 55              Collimation Tasks - T. Markiewicz
                                        Task: Use RHIC Data
                                 to Benchmark LHC Tracking Codes

    Scope:
       – Install SixTrackwColl particle tracking code at BNL and configure it to
         simulate RHIC performance for both ions and protons.
       – Take systematic proton and ion data and compare observed beam
         loss with predictions
       – Test (and perhaps help to develop) algorithms proposed for the
         automatic set up of a large number of collimators

    Status: Guillaume Robert-Demolaize (ex-CERN) hired January 2007 BNL
    • The tracking tools developed at CERN are now up and running for RHIC
      proton beam simulations.
    • Even though the tracking code itself is portable and can be used for any
      machine, the aperture model is specific to each machine studied
                 => had to generate one for the RHIC lattice !
    • While still in its early stages, it is already fully compatible with the
      established tools; some effort is still dedicated in refining it (transition
      regions, local aperture restrictions…).
    • The events selected so far contained enough data for the first
      preliminary studies that allowed for debugging of the new functions of
      the codes
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                      Task 2: Progress Since June 2005 DOE Review



        (1)
                  (2)
                                                              (2)




                                                                    (1)



                                                                Effect on BLM signal
                  Simulating a horizontal
                     jaw movement




LARP DOE Review - 05 June 2007              Slide n° 4 / 55                 Collimation Tasks - T. Markiewicz
                         Task: Model tertiary collimators at the LHC
                                 experimental insertions

 •    Study of betatron collimation and beam-gas debris cleanup by
      tertiary collimators in IP1 & IP5 complete
      – Peak energy deposition in IRQ is more than two orders of
          magnitude below the quench limits at normal operation and
          nominal parameters.
           •     Tungsten is noticeably better than copper (1 meter).
           •     Betatron cleaning contribution dominates over beam-gas, esp. for 0.22-
                 hr beam life time.
      – Tertiary collimators noticeably reduce machine backgrounds at
        small radii (pixels, tracker) and protect these components at
        beam accidents.
           •     Backgrounds and radiation levels in the CMS and ATLAS detectors are
                 dominated – at nominal luminosity - by pp-collisions.
           •     Tungsten is better.
           •     There is only a minor effect of TCTs at radii > 1 m.
 •    .Momentum cleaning and an impact of a single bunch loss on TCT
      still need to be addressed (need someone to help!).
LARP DOE Review - 05 June 2007             Slide n° 5 / 55            Collimation Tasks - T. Markiewicz
            Neutron (bgas & pp) and Muon Fluxes (bgas) in CMS




                                                   With tertiary collimators in

LARP DOE Review - 05 June 2007   Slide n° 6 / 55                Collimation Tasks - T. Markiewicz
        US LHC Accelerator Research Program
                BNL - FNAL- LBNL - SLAC




            LARP Rotatable Collimators
            for LHC Phase II Collimation




Representing Gene Anzalone, Eric Doyle, Lew Keller & Steve Lundgren
                                 CERN Collimation Plan & Schedule


0) Assume SLAC LARP develops Rotatable Collimator
1) Develop TWO other complementary designs
2) Develop a test stand for the three designs
3) Fabricate 30 Phase II collimators of chosen design & 6 spares

The target schedule for phase 2 of LHC collimation:
2005     Start of phase 2 collimator R&D at SLAC (LARP) with CERN support.
2006/7 Start of phase 2 collimator R&D at CERN.
2009     Completion of three full phase 2 collimator prototypes at CERN and SLAC.
         Prototype qualification in a 450 GeV beam test stand at CERN.
2010     Installation of prototypes into the LHC and tests with LHC beam at 7 TeV.
         Decision on phase 2 design and production at end of year
2011     Production of 36 phase 2 collimators.
2012     Installation of 30 phase 2 collimators during the 2010/11 shutdown.
         Commissioning of the phase 2 collimation system.
         LHC ready for nominal and higher intensities.
RED      One year slip from recent white paper, “Second Phase LHC Collimators”

LARP DOE Review - 05 June 2007               Slide n° 8 / 55        Collimation Tasks - T. Markiewicz
                                      June 2006 DOE Review
                            Introduce new jaw-hub-shaft design which
                              eliminates central stop & flexible springs




                                  x5 improvement in thermal deformation
                                  1260 um  236 um (60kW/jaw, t=12min)
                                   426 um  84 um (12kW/jaw, t=60min)




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                                   June 2006 DOE Review
                  Introduce new reverse-bend winding concept for the
                        cooling coil which eliminates the 3 end loops,
                   permitting longer jaws and freeing up valuable space
                  for jaw supports, rotation mechanism and RF-features
                                             Sheet Metal
                                             formed RF
                                             transition
                                                                      4-1/2 Turns without failure
 EXTERNAL COIL
 PERMITS 1 REV
 OF JAW




                                                                                Restrain each tube
                                                                              on centerline of bearing

                                 136mm dia



                                                              960mm

LARP DOE Review - 05 June 2007                     Slide n° 10 / 55               Collimation Tasks - T. Markiewicz
                         Main accomplishments in the last year


• Hundreds of 3-D concept & 2-D manufacturing
  drawings made
• Rotation & support mechanism fully designed and
  manufactured
• Many test pieces manufactured and examined,
  tooling developed, and, especially, brazing protocols
  worked out
• All parts for first full length jaw assembly
  manufactured & in-house
• Test lab fully wired, plumbed and equipped
LARP DOE Review - 05 June 2007         Slide n° 11 / 55   Collimation Tasks - T. Markiewicz
                    Model showing 42.5 winds of coil on Mandrel with
                    80mm wide space for U-Bend at downstream end




LARP DOE Review - 05 June 2007         Slide n° 12 / 55        Collimation Tasks - T. Markiewicz
                       Comparison of Hollow Moly shaft and
                        Solid Copper Shaft to same FLUKA
                        secondaries: Improved deflections


                                  Solid Cu, 75cm tapered jaw,       Tubular Moly, 95 cm straight
                                        asymmetric hub                  jaw, symmetric hub
                                 Steady State     t = 12 min        Steady State           t = 12 min
                                   t=1 hour       for 10 sec          t=1 hour             for 10 sec
    Gravity sag                              200 um                             67.5 um
    Power absorbed                 11.7 kW          58.5 kW           12.9 kW                64.5 kW
    Peak Temp.                     66.3 °C            197 °C           66 °C                  198 °C
    Midjaw Dx                      100 um            339 um           83.6 um                236 um
    Effective Length                51 cm             25 cm            74 cm                   39 cm
    Sagitta                        221 um            881 um           197 um                 781 um




LARP DOE Review - 05 June 2007                   Slide n° 13 / 55                Collimation Tasks - T. Markiewicz
                            Current Upstream end with actuator and
                                         cooling lines




LARP DOE Review - 05 June 2007             Slide n° 14 / 55          Collimation Tasks - T. Markiewicz
                    Introduce new Internally actuated drive for rotating
                             after beam abort damages surface

                                                                         NLC Jaw Ratchet
  Universal Joint Drive Axle                                             Mechanism
         Assembly
•Thermal expansion
•Gravity sag
•Differential transverse
displacement




                                         New rotation
                                            drive with
                                             “Geneva
LARP DOE Review - 05 June 2007
                                         Mechanism”
                                         Slide n° 15 / 55          Collimation Tasks - T. Markiewicz
                                 Upstream end vertical section


    Lundgren
                                        Jaw
                                                                         Geneva Mechanism

                                                                                    Worm Gear
               Shaft




         1-2mm Gap



      Water Cooling
        Channel
                                                                         U-Joint Axle

                            Diaphragm                            Support Bearings

LARP DOE Review - 05 June 2007                Slide n° 16 / 55                  Collimation Tasks - T. Markiewicz
                                     RF Shielding:
                     ONLY PART THAT REMAINS TO BE DESIGNED
                                   Baseline Concept
                      Tie-Rods with Fingers Connect Jaws & Tank
    Issues:
        – At a few 10s of grams per finger (.1 mΩ/contact) force causes
          excessive deflection of the tie-rod holding fingers
        – Cooling required




                                                         Tie-Rods



    Discussions with CERN and PeP-II experts in progress
LARP DOE Review - 05 June 2007        Slide n° 17 / 55              Collimation Tasks - T. Markiewicz
                                 Revised RF Spring configuration
                                       under consideration



   Jaw facet RF springs                                        Double Wedge Adapters mount
      mount on Tank                                             across Tank ceiling & floor
      ceiling & floor




  2 RF springs mount to
      each Adapter
                                                                   Shorter length springs
                                                                       also mount to
                                                                    Tank ceiling & floor




Note: Jaw facet springs are wide enough for line contact thru full transverse travel range


LARP DOE Review - 05 June 2007              Slide n° 18 / 55            Collimation Tasks - T. Markiewicz
                                 RF Contact Springs for Investigation




LARP DOE Review - 05 June 2007                 Slide n° 19 / 55         Collimation Tasks - T. Markiewicz
                Cooling Tube                                  BrazeTest #1
      Jaw                          Center Mandrel          (shown June 2006)




    ~70 mm                                   ~100 mm dia
      dia




                             ~100 mm




LARP DOE Review - 05 June 2007                 Slide n° 20 / 55         Collimation Tasks - T. Markiewicz
                     Aluminum Mandrel for Coil Winding Test and to
                     test 3-axis CNC Mill before cutting 200mm and
                                 950mm Copper Mandrels

                                       Cooling Tube aligner




                                      200mm




LARP DOE Review - 05 June 2007         Slide n° 21 / 55       Collimation Tasks - T. Markiewicz
                                  Development of Winding Tooling

                                  Aluminum Mandrel with Coil Wound




                       Vise-Type                                 Roller-Type

                                 Test Winding the 200mm Copper Mandrel

LARP DOE Review - 05 June 2007                Slide n° 22 / 55           Collimation Tasks - T. Markiewicz
                       Fabrication of Quarter Jaws for 2nd Braze Test




LARP DOE Review - 05 June 2007            Slide n° 23 / 55        Collimation Tasks - T. Markiewicz
                                 Final Wind of 200mm Copper Mandrel




LARP DOE Review - 05 June 2007                Slide n° 24 / 55        Collimation Tasks - T. Markiewicz
                                       First 200mm Prototype
                                 Before-After Brazing Coil to Mandrel




                                                          4 braze cycles were required before part
                     Pre-Coil-Braze                        deemed good enough to do jaw braze
                                                          Learned a lot about required tolerances
                                                            of cooling coil and mandrel grooves

LARP DOE Review - 05 June 2007                 Slide n° 25 / 55               Collimation Tasks - T. Markiewicz
                                 More Winding Tooling Developed




                    1m winding tooling                         Mill vise as precision bender




LARP DOE Review - 05 June 2007              Slide n° 26 / 55                Collimation Tasks - T. Markiewicz
                                 Full Length Molybdenum Shaft



                                                              1mm raised shoulder
                                                              (Hub) at center




LARP DOE Review - 05 June 2007             Slide n° 27 / 55       Collimation Tasks - T. Markiewicz
                        Braze Test#2 Delivered 19 Dec 2006




LARP DOE Review - 05 June 2007        Slide n° 28 / 55   Collimation Tasks - T. Markiewicz
                                 Vacuum Bake Test Results: 4/1/07
                                       ~3x over LHC Spec
                                                 1st Jaw Braze Test Assembly has been vacuum
                                                 baked at 300 degrees C for 32 hours.

                                                 •LHC Requirement = 1E-7 Pa = 7.5E-10 Torr
                                                 •Baseline pressure of Vacuum Test Chamber:
                                                             4.3E-7 Pa (3.2E-9 Torr)
                                                 •Pressure w/ 200mm Jaw Assy. in Test Chamber:
                                                             4.9E-7 Pa (3.7E-9 Torr)
                                                 •Presumed pressure of 200mm lg. Jaw Assy.:
                                                             6.0E-8 Pa (4.5E-10 Torr)
                                                 •Note: above readings were from gauges in the
                                                 foreline, closer to the pump than to the Test
                                                 Chamber. Pressures at the part could be higher.

                                                 SLAC vacuum group has suggested longitudinal
                                                 grooves be incorporated into the inner length of
                                                 jaws; incorporated into next prototype

                                                 Next steps:
                                                 •Use in Moly-Hub cold press fit
                                                 Sectioning & examine braze quality
LARP DOE Review - 05 June 2007               Slide n° 29 / 55                 Collimation Tasks - T. Markiewicz
                         Aluminum Test Mandrel with 80mm Gap for
                              Downstream U-Bend (11/17/06)




LARP DOE Review - 05 June 2007           Slide n° 30 / 55     Collimation Tasks - T. Markiewicz
                     Braze Test #3: 200mm Cu mandrel with U-Bend
                                                         Tubing Wound and Tack Welded
     Upstream end of mandrel                                to Mandrel at the U-Bend




                                                         Note stub ends of cooling tube


LARP DOE Review - 05 June 2007        Slide n° 31 / 55                        Collimation Tasks - T. Markiewicz
                                     Braze Test #3:
                     Coil-mandrel brazed & 8 ¼-round jaws prepped




   Next steps:                           After 2 braze cycles, OD &
    -Braze jaws by mid-June             braze wire grooves machined
          NB: experience is indicating 20cm long full round jaws may
          be feasible
    -Vacuum test?
    -Section & examine braze quality
LARP DOE Review - 05 June 2007         Slide n° 32 / 55      Collimation Tasks - T. Markiewicz
                           Fear of Copper-Moly Braze Joint Leads to
                                    Mini Devoted R&D Cycle


                                                                           Initial plan to braze one long
                                                                           Mo shaft with raised hub to
                      #1                                                   inner radius of Cu mandrel
                                                                      #2   deemed unworkable
                                                                           Brazing HALF-LENGTH
                                                                      #3
                                                                           shafts to a COPPER hub
                                                                           piece and THEN brazing
                                                                           the Cu hub to the Cu
                                                                           mandrel deemed possible
                                              #4                           First test if Mo “backing
                                                                           ring” sufficient to keep Mo
                                                                           and Cu in good enough
                                 #1 - Mandrel Dummy
                                 #2 - Mo Shaft Dummy                       contact for a strong braze
                                 #3 - Mo Backing Ring                      joint
                                 #4 - Cu Hub with braze wire grooves


LARP DOE Review - 05 June 2007                     Slide n° 33 / 55                  Collimation Tasks - T. Markiewicz
                 Cu-Mo Hub Braze Test Assembly after 3 additional
                heat cycles (to mimic full assembly procedure) then
                sectioned. Moly-Cu Joint Declared “Good” by SLAC
                            Braze Shop Experts, but…..

                                                            •Grain boundary issues?
                                                            •Possible fracturing?

                                                            Samples sliced &
                                                            polished and sent to
                                                            Physical Electronics
                                                            lab for analysis:
                                                            Fractures evident

                                                            Cu-Mo joints
                                                            we care about


                                                           1mm
                                                           expansion gap


  Small holes held braze wire

LARP DOE Review - 05 June 2007        Slide n° 34 / 55        Collimation Tasks - T. Markiewicz
                        Details of Shaft attachment to the Collimator
                          Interference Fit versus Improved Braze



                                                             Braze Hub improvement includes a
                                                             flexible Molybdenum end that prevents
                                                             the copper Hub stub from pulling away
                                                             from the Mo.




Copper Jaw is constrained on the outside diameter
with Carbon and when heated to ~ 900 degrees C
is forced to yield so that upon cooling to ~ 500
degrees C the inner diameter begins to shrink onto
the Mo Shaft resulting a substantial interference fit.

LARP DOE Review - 05 June 2007            Slide n° 35 / 55                   Collimation Tasks - T. Markiewicz
                         Full length Mandrel: In-House & Inspected

          – Most groove widths meet specification except for a few at each end.
          – Positioning of distorted areas could indicate damage was done by
            excessive forces imparted by hold down fixturing during machining.
          – Future Mandrel drawings will include a note warning about potential
            damage caused by excessive clamping forces.




                                                                out of specification
                                                                grooves

LARP DOE Review - 05 June 2007            Slide n° 36 / 55       Collimation Tasks - T. Markiewicz
                         Exploded view of CAD model of Flex Mount




                                                                                     U-Joint Flexes for
                                                                                     Shaft “sag” and
   Triple Cog                                                                        “Slewing”
   Geneva Drive
   Wheel required
   for 512 clicks per
   facet                                                    Water Cooling
                                                            Inlet and outlet



LARP DOE Review - 05 June 2007           Slide n° 37 / 55                      Collimation Tasks - T. Markiewicz
                                 Up Beam Flex Mount Assembly
                                 showing Ratchet and Actuator




LARP DOE Review - 05 June 2007           Slide n° 38 / 55       Collimation Tasks - T. Markiewicz
                             Test Lab Preparation ~Finished

                                                                   Adjacent 16.5 kW Chiller
           Clean space with gantry access
           Basic equipment: Granite table, racks,
            hand tools
           Power supplies to drive heaters
           Chiller & plumbed LCW to cool jaw
           480V wiring for heater power supplies
               • required engineering review, safety review,
                 and multiple bids (?!)
           Acquire Heaters
               • 5kW resistive heaters from OMEGA
           PC & Labview
                Rudimentary software tests only
                                                                   Heater Power Supplies
           National Instruments DAQ with ADCs                  staged for installation in rack
            • Data Acquisition and Control Module
            • 32-Channel Isothermal Terminal Block
            • 32-Channel Amplifier
           Thermocouples
           Capacitive Sensors
          – Vacuum or Nitrogen (?)
          – Safety Authorization (!!!)
LARP DOE Review - 05 June 2007               Slide n° 39 / 55              Collimation Tasks - T. Markiewicz
                     CONCERN #1: Still have not brazed nor thermally
                          tested a full length jaw assembly

Main Steps Still Needed
• After 200mm Jaw tests Completed Satisfactorily Freeze brazing protocol
• Jaw 1/4 sections (16 needed of 24 now at SLAC) require slight modifications
  for braze gap requirements.
• Moly shaft (at SLAC) will perhaps need to be cut in two pieces and brazed
  to copper hub or interference fit made
• Drill Cu mandrel for Moly Shaft
• Wind coil using in-house SLAC Copper,
   – Need to order more (Finland 20 week delivery) OFE 10mm x 10mm or
      use CERN order of Ni-Cu alloy, anneal & wind mandrel
• Several braze Cycles
• Drill jaw to accept resistive heater
   – Understand (ANSYS) any change to expected performance


LARP DOE Review - 05 June 2007         Slide n° 40 / 55       Collimation Tasks - T. Markiewicz
                                 Concern#2: Still do not have a complete
                                    mechanical (=“RC1”) prototype


   • Successful thermal performance of first full length jaw
   • Complete the design of RC1 RF features
   • Fit-up and initial tests of support/rotation mechanism on 1st full length jaw
   • Complete fabrication of second and third jaws (Glidcop?, Moly??) with
     full support assembly on the four corners
   • Acquisition of Phase I support & mover assemblies
      – CERCA/AREVA REFUSES to supply SLAC
      – Recent (18 APR 07) proposal to sell SLAC a non-functional CERN
         TCS collimator with damaged tank & bellows
   • Remodeling of CERN parts for interface to US parts
      – An enlarged vacuum tank has been modeled and some CERN
         support stand modifications have been identified
              • No fabrication drawings have been done as yet
   • Acquire motors, sensors,.. Not part of CERN TCS purchase


LARP DOE Review - 05 June 2007                 Slide n° 41 / 55       Collimation Tasks - T. Markiewicz
                      Vacuum tank, jaw positioning mechanism and
                        support base derived from CERN Phase I




                                                                 beam
LARP DOE Review - 05 June 2007         Slide n° 42 / 55   beam          Collimation Tasks - T. Markiewicz
                                  Inter-Lab Collaboration


    Good will & cooperation limited only by busy work loads
      – Regular ~monthly video meetings
      – Many technical exchanges via email
      – CERN FLUKA team modeling Rotatable Collimator
      – CERN Engineering team looking at SLAC solid-model of RC and
        independently doing ANSYS calculations of thermal shock
      – CERN physicists
               • investigating effects of Cu jaws at various settings on collimation
                 efficiency
               • Participating in discussion of RF shielding design
          – SLAC Participation in upcoming CERN Phase II brainstorming
            meeting
          – Ralph Assmann to visit SLAC in summer 2007


LARP DOE Review - 05 June 2007             Slide n° 43 / 55              Collimation Tasks - T. Markiewicz
                   Examples of CERN Collaboration on SLAC Phase II Design




                                      Elias Metral Addressing RF Concerns




                  Luisella Lari




                                                         Collaboration on ANSYS
LARP DOE Review - 05 June 2007        Slide n° 44 / 55                 Collimation Tasks - T. Markiewicz
                       Collaboration on Tracking Efficiency Studies
                                  Chiara Bracco - CERN




• Phase II collimators should provide x 2.5 improvement in global inefficiency
• Beam intensity limitations are due to losses in the dispersion suppressor above the
  quench limit. These losses are not improved by metallic secondary collimators
• Solutions must be found to improve performance of primary collimators

LARP DOE Review - 05 June 2007           Slide n° 45 / 55          Collimation Tasks - T. Markiewicz
                Resource Loaded Schedule Showing June 2008 for Full RC1




LARP DOE Review - 05 June 2007        Slide n° 46 / 55         Collimation Tasks - T. Markiewicz
                                 LARP Collimator Delivery Schedule

    Done                 Braze test #1 (short piece) & coil winding procedures/hardware
                         Prep heaters, chillers, measurement sensors & fixtures, DAQ & lab
                         Section Braze test #2 (200mm Cu) and examine –apply lessons
                         Braze test #3 (200mm Cu) – apply lessons learned
                         Fab/braze 930mm shaft, mandrel, coil & jaw pieces
    2007-09-01           1st full length jaw ready for thermal tests
                         Fab 4 shaft supports with bearings & rotation mechanism
                         Fab 2nd 930mm jaw as above with final materials (Glidcop) and
                         equip with rf features, cooling features, motors, etc.
                         Modify 1st jaw or fab a 3rd jaw identical to 2nd jaw, as above
                         Mount 2 jaws in vacuum vessel with external alignment features
    2008-07-01           2 full length jaws with full motion control in vacuum tank available for
                         mechanical & vacuum tests in all orientations (“RC1”)
                         Modify RC1 as required to meet requirements
    2009-01-01           Final prototype (“RC2”) fully operational with final materials, LHC
                         control system-compatible, prototype shipped to CERN to beam test
LARP DOE Review - 05 June 2007                  Slide n° 47 / 55             Collimation Tasks - T. Markiewicz
                                 Phase II Task Summary


 There has been continued progress in design and excellent but slow
   progress on the necessary small scale projects to finalize procedures.
 Time estimates for thermal test of first jaw and construction of first 2 jaw
   prototype (RC1) are expanding. In June 2006 DOE was told
           “Expect thermal tests and completely tested RC1 device
                  by end of FY06 and mid-FY07, respectively”
                              Now need to say:
      “Expect thermal tests to begin and completely tested RC1 device
                  by end of FY07 and end-FY08, respectively”

 Jeff Smith (Ph.D., Cornell) joins SLAC Collimation team ~July 23, 2007
     – 25% ILC, 75% LARP



LARP DOE Review - 05 June 2007          Slide n° 48 / 55       Collimation Tasks - T. Markiewicz
                        Task #4: Irradiation Damage Assessment of
                            LHC collimator materials: N. Simos

Scope:
    Irradiate 2-D weave carbon-carbon and exact graphite used in Phase I jaws
       plus materials considered viable for Phase II jaws
         • BNL AGS/BLIP (70 mA of 117 & 200 MeV protons)
    Measure material properties: thermal expansion, mechanical properties,
     thermal conductivity/diffusivity and thermal shock
         • BNL “Hot Cell” Sample Measurement Facility
Status
2005-06: Irradiate 2D-weaved CC composite & measure CTE – DONE
2006-07: Irradiate Cu & Glidcop & measure CTE - DONE
To Do: Measurements of Thermal Conductivity & Mechanical Properties
NB1: 2006 exposure included graphite, super-invar, gum metal, Ti Alloy (6Al-4V),
   Tungsten Tantalum, AlBeMet, Graphite bonded to Cu & Ti
In Progress: neutron exposure of 2006 Phase II collimator materials
Plan: Finish “To Do” & analyze neutron irradiated samples to correlate results
   with proton irradiated data. In principle will allow for the use of the wealth of
   radiation data generated from reactor operations
NB2: Nick (not LARP) considers ALL these materials as LHC relevant
LARP DOE Review - 05 June 2007            Slide n° 49 / 55       Collimation Tasks - T. Markiewicz
                        CTE Measurements of Irradiated 3D C-C




  fluence ~ 1020 protons/cm2
   Irradiation Damage Self Anneals through thermal cycling as seen in 2-D C-C
LARP DOE Review - 05 June 2007        Slide n° 50 / 55       Collimation Tasks - T. Markiewicz
                        CTE Measurements of Irradiated Copper




  fluence ~ 1021 protons/cm2
LARP DOE Review - 05 June 2007        Slide n° 51 / 55    Collimation Tasks - T. Markiewicz
                       CTE Measurements of Irradiated GlidCop




  fluence ~ 1021 protons/cm2
LARP DOE Review - 05 June 2007        Slide n° 52 / 55   Collimation Tasks - T. Markiewicz
                       Carbon Composite & Graphite Damage


                                                         3-D carbon




                                                                        Graphite

                                 2-D carbon



  fluence ~ 1021 protons/cm2
LARP DOE Review - 05 June 2007        Slide n° 53 / 55           Collimation Tasks - T. Markiewicz
                                  Conclusions-Platitudes



    The four LARP Collimation program tasks
       – Provide R&D results to a key LHC subsystem that will need to
         perform well from the beginning
               • Strong support for all tasks from LHC Collimation group
          – Play to the unique strengths of the US Labs
               •   RHIC as a testbed
               •   BNL irradiation test facilities
               •   Fermilab’s simulation strength
               •   SLAC’s Linear Collider collimator engineering program




LARP DOE Review - 05 June 2007             Slide n° 54 / 55            Collimation Tasks - T. Markiewicz
                                 Conclusions-Pessimistic


    • No real work has happened at BNL to understand RHIC data until recently.
      Progress may be made soon, but will analysis of existing RHIC data really add
      anything to LHC design at this point?
    • FNAL Tertiary collimator simulations too little, too late: Main choice (W vs. Cu)
      made, collimators fabricated & installed. These studies will never be truly
      over. Is that so bad?
    • BNL irradiation studies support 2-D C-C for Phase I (after the fact) and
      Cu/GLIDCOP for Phase II (after the fact). Not all measurements of relevant
      physical properties made yet. Part of an ongoing study of encompassing
      many materials of general academic but not necessarily LHC-relevant
      interest.
    • SLAC team working hard but:
       – Thermal mechanical tests > 1 year late: what will happen if they do not
          deliver performance
       – Need to start construction of “RC1” at beginning of FY08
       – Need CERN mover assembly as there is no way we can re-manufacture
          so many parts
       – Need other improvements (to primaries?) to improve quench limit
       – CERN to provide 2 Phase II secondary collimator designs. What then?
LARP DOE Review - 05 June 2007          Slide n° 55 / 55             Collimation Tasks - T. Markiewicz
Bonus Slides
               Specification Changes Relative to April 2006 Design

                                                          RC1 Report 12/12/05               Current
                                    spec                  value                             value
                    jaw             Length                95cm including 10cm end tapers    93cm with 1cm end
                                                                                            tapers
                                    Diameter              136mm                             20 facets, tangent to
                                                                                            136mm
                                    Material              Copper                            Glidcop AL-15
                                    cooling               Embedded helical channel          Reduced helix depth,
                                                                                            Helix pitch reversal
                                    Special features      Circumferential slots to reduce   eliminated
                                                          thermal-induced bending, if no
                                                          RF problems
                                    deformation           <25um toward beam; <325mm         Inward: 84um SS,
                                                          away in steady state; <750um      236um Trans – 1st
                                                          away in 10 sec transient          coll to be set at 8.5 
                                                                                            for clearance
                                    Range of motion       25mm per jaw, including +/-       27.5 mm per jaw
                                                          5mm beam location drift           including +/- 5mm
                    Aperture stop   Range of motion       Controls aperture from 5-15       eliminated
                                                          sigma (2-6mm full aperture),
                                                          must float +/- 5mm as jaws are
                                                          moved to follow beam drift
                    Heat load       Steady state          11.3 kW                           12.9kW
                                    Transient             56.5 kW                           64.5kW
                    RF contacts     configuration         Sheet metal parts subject to      New geometry
                                                          CERN approval

LARP DOE Review - 05 June 2007                         Slide n° 57 / 55                       Collimation Tasks - T. Markiewicz
                     Heat deposited in major components
                    (W/m^3) in 1 hr beam lifetime operation




Component                                                    Units   Upbeam           Downbeam
Stub shaft, aluminum                                         W/m^3   6.5e3            52e3
Bearing, Si3N4                                               W/m^3   8.3e3            66.4e3
Image current bridge, aluminum                               W/m^3   150e3            400e3
Mo shaft (~const in z, concentrated in =120o)               W       520
Jaw, Glidcop AL-15 (heat highly variable in z and )         kW      12.8




LARP DOE Review - 05 June 2007            Slide n° 58 / 55             Collimation Tasks - T. Markiewicz
                                    Major jaw dimensions and
                                 calculated cooling performance

Component                                                      dimension             units
Jaw OD tangent to 20-faceted surface                           136                   mm
Jaw OD to facet vertices                                       137.7                 mm
Jaw ID                                                         66                    mm
Jaw length, including 10mm (in z) x 15o taper on each end      930                   mm
Mo Shaft OD                                                    64                    mm
Mo Shaft ID                                                    44                    mm
Hub length (centered)                                          150                   mm
Cooling tube OD x ID (square x square)                         10 x 7                mm
Embedded helix – center radius                                 80                    mm
Helix – number of turns                                        ~47                   -
Cooling tube length – helix + entry + exit from vac tank       ~16                   m
Flow per jaw                                                   9                     l/min
Velocity                                                       3                     m/s
Water temperature rise (SS 12.8 kW per jaw)                    20.3                  C
Pressure drop                                                  2.4                   bar


LARP DOE Review - 05 June 2007              Slide n° 59 / 55      Collimation Tasks - T. Markiewicz
                                 One Year Later…


At June 2006 DOE Review we introduced
• New jaw-hub-shaft design which eliminates central stop & flexible springs
• New reverse-bend winding concept for the cooling coil which eliminates
  the 3 end loops, permitting longer jaws and freeing up valuable space for jaw
  supports, rotation mechanism and RF-features
• Internally actuated drive for rotating after beam abort damages surface
Main accomplishments in the last year
• Many test pieces manufactured and examined, tooling developed, and,
  especially, brazing protocols worked out
• Hundreds of 3-D concept & 2-D manufacturing drawings made
• Rotation & support mechanism fully designed and manufactured
• All parts for first full length jaw assembly manufactured & in-house
• Test lab fully wired, plumbed and equipped
BUT…
   – Still have not brazed nor thermally tested a full length jaw assembly
   – Still do not have a complete mechanical (=“RC1”) prototype
LARP DOE Review - 05 June 2007      Slide n° 60 / 55        Collimation Tasks - T. Markiewicz
                       Summary of New Baseline Configuration

Jaw consists of a tubular jaw with embedded cooling tubes, a concentric inner shaft
      joined by a hub located at mid-jaw
    –     Major thermal jaw deformation away from beam
    –     No centrally located aperture-defining stop
    –     No spring-mounted jaw end supports
Jaw is a 930mm long faceted, 20 sided polygon of Glidcop
Shorter end taper: 10mm L at 15o (effective length 910mm)
Cooling tube is square 10mm Cu w/ 7mm square aperture at depth = 24.5 mm
Jaw is supported in holder
    –     jaw rotate-able within holder
    –     jaw/holder is plug-in replacement for Phase I jaw
Nominal aperture setting of FIRST COLLIMATOR as low as 8.5 
    –     Results in minimum aperture > 7 in transient 12 min beam lifetime event
          (interactions with first carbon primary TCPV)
    –     Absorbed power relatively insensitive to aperture: for 950mm long jaw
          p=12.7kW (7), p=12.4kW (8.23)
Auto-retraction not available for some jaw orientations
Jaw rotation by means of worm gear/ratchet mechanism  “Geneva Mechanism”
LARP DOE Review - 05 June 2007        Slide n° 61 / 55             Collimation Tasks - T. Markiewicz
                                  Cu-Mo Hub Braze Test parts




       #2




                #1 - Mandrel Dummy (not shown)
                #2 - Mo Shaft Dummy                        #3       #4
                #3 - Mo Backing Ring
                #4 - Cu Hub with braze wire grooves


LARP DOE Review - 05 June 2007                   Slide n° 62 / 55        Collimation Tasks - T. Markiewicz
                Up Beam Flex Mount – Rotation Assembly Complete



     Design features that may not be apparent in the photos include:
       – Integral water cooling channel.
       – Flexibility for length increase of the Collimator Shaft (proton
         load).
       – Compensation for Shaft (in-plane) end angle rotation (sag).
       – Flexibility for the +/- 1.5mm offsets required during “slewing”.
       – Does not require an extra drive and control (uses existing
         systems).
       – 2.5mm motions advance the ratchet 1 “click”.
       – 512 “clicks” advance the Collimator to the next facet.
       – Facet advancing is ~5% of the lifting load for Vertical
         Collimator


LARP DOE Review - 05 June 2007      Slide n° 63 / 55      Collimation Tasks - T. Markiewicz
                                 PLASTIC DEFORMATION of ENTIRE JAW
                                    after a BEAM ABORT ACCIDENT?

   PRELIMINARY RESULT:
                                                                                      Doyle
     – 0.27 MJ dumped in 200 ns into ANSYS model
     – Quasi steady state temperature dependent stress-strain
              • bilinear isotropic hardening
         – Result:
              • plastic deformation of 208 um after cooling, sagitta ~130um
                 – Jaw ends deflect toward beam
              • Jaw surfaces at 90 to beam impact useable, flat within 5 um


                                       Beam side
                            54 um
                                       Far side                               Melted
                                                                              material
                                                                              removed




LARP DOE Review - 05 June 2007                     Slide n° 64 / 55   Collimation Tasks - T. Markiewicz
                     Rotatable Collimator Activation & Handling




                                            Need dose rate at ~1m; Mokhov et al
LARP DOE Review - 05 June 2007        Slide n° 65 / 55           Collimation Tasks - T. Markiewicz
                          BNL Irradiation (BLIP) and Post-Irradiation
                                 Testing Facilities and Set-Up
           Layout of multi-material
       irradiation matrix at BNL BLIP

                                                                                      Dilatometer
                                                                                         Set-up
                                                                                     In Hot Cell #1




                                                              Remotely-
                                                               operated
                                                                tensile
  Test                                                          testing
Specimen                                                      system in
Assembly                                                      Hot Cell #2

LARP DOE Review - 05 June 2007             Slide n° 66 / 55                 Collimation Tasks - T. Markiewicz
                                 Task #4 Status


    Completed:
    •   Phase I Carbon-Carbon irradiation
    •   Sample activation measurements (mCi, dpa)
    •   Thermal Expansion of C-C specimens
    •   Preparation of Phase II material samples




                                         Specimens highly degraded under dose
                                            >> LHC collimator jaws will see.




LARP DOE Review - 05 June 2007      Slide n° 67 / 55            Collimation Tasks - T. Markiewicz
                        CTE Measurements of Irradiated 2D C-C

               Strong (fiber plane) direction                       Weak (┴fiber plane) direction




                                                                   7.50 mCi




                                                 LHC collimator operating temperature regime

             Irradiation Damage Self Anneals through thermal
                 cycling in both strong and weak directions
LARP DOE Review - 05 June 2007                  Slide n° 68 / 55                   Collimation Tasks - T. Markiewicz
                                 Irradiation damage assessment – to date

      • While all carbon composites tested (2005-2007) exhibit stability in
        their thermal expansion coefficient in the temperature range they are
        expected to operate normally, they experience a dramatic change in
        their CTE with increased radiation. However they are able to fully
        reverse the “damage” with thermal annealing
      • Carbon composites also showed that with increased proton fluence
        (> 0.2 10^21 p/cm2) they experience serious structural degradation.
        This finding was confirmed for the family of such composites and not
        only for the 2-D composite used in the LHC.
      • It was also experimentally shown that under similar conditions,
        graphite also suffers structurally the same way as the carbon
        composites
      • Proton radiation was shown to not effect the thermal expansion of
        Copper and Glidcop that are considered for Phase II
      • Encouraging results were obtained for super-Invar, Ti-6Al-4V alloy
        and AlBeMet

      In Progress:
      • Set up of existing tensile test apparatus & test of irradiated C-C
      • Set up of new thermal conductivity apparatus

LARP DOE Review - 05 June 2007                Slide n° 69 / 55       Collimation Tasks - T. Markiewicz

								
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