Detectors for the FCU by 56K74R

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									                   Detectors for the FCU
                                         WSO/UV
                World Space Observatory / Ultraviolet Project




                                            Michela Uslenghi
WSO/UV Italian web site:                    INAF/IASF Milano
http://www.oact.inaf.it/wso/index.htm/
                               Outline
      • Overview of the Field Camera Unit
      • UVO Detector
         – CCD
         – FEE
      • NUV & FUV Detectors
         – Requirements
         – Selection process
         – Baseline architecture
         – MCP intensifier
         – Readout system
         – FEE
      • R&D

Leicester, December 3-5 2007                WSO Detector Workshop
                  Imager requirements
    • Large wavelength coverage (115-700 nm)
    • Large field of view
    • High spatial resolution
       – Morphological studies (e.g. planets, planetary nebulae,
         star formation regions, external galaxies)
       – High accuracy stellar photometry
       – High accuracy stellar astrometry
       – Resolve stars in crowded fields (e.g. in star clusters,
         external galaxies, star formation in AGNs)
    • High time resolution in the UV


Leicester, December 3-5 2007                WSO Detector Workshop
           Science requirements for the
                   FCU camera
           Parameter                             Channel

                                Far-UV       Near-UV         UV-Optical


           Spectral Range      115-190 nm   150-280 nm        200-700 nm


           Field of View        6.6’x6.6’      1’x1’            4.7’x4.7’

           Scale                0.2”/pix    0.06”/pix          0.07”/pix

           Pixel Size            20m         20m               15m

           Array Size            2kx2k        2kx2k              4kx4k

           Detector            MCP (CsI)    MCP (CsTe)     CCD (UV optimized)



Leicester, December 3-5 2007                                WSO Detector Workshop
                                  FCU Layout

                                                    UVO Channel




                    NUV Channel       FUV Channel




Leicester, December 3-5 2007                              WSO Detector Workshop
                        Mechanical Design
                                        Enclosure
                                                                UVO Channel



                   UVO Filter Wheel                                              Baffles

                                                                                   Fore Optics

                       Enclosure


                                                                              FUV Filter Wheel
                                                                                Detector
                  NUV Filter Wheel


                 NUV Channel
                                                                           FUV Channel
                   S/C Optical Bench                                       FCU Optical Bench

                                                                Detector

                                                     Baffle
                                                    Enclosure
                                       Detector




Leicester, December 3-5 2007                                          WSO Detector Workshop
                      Operational Modes

           – Imaging (FUV, NUV, UVO)
           – Slitless spectroscopy (FUV, NUV, UVO)
           – Polarimetry       (NUV, UVO)
           – Slitless spectro-polarimetry   (NUV)
      • High Temporal Resolution Modes
           – Time Tag (MCP)
           – Windowing (CCD, MCP)

Leicester, December 3-5 2007         WSO Detector Workshop
                               UVO Detector
      • The UVO channel will extend from UV to visual
        wavelengths
      • The pixel scale of this channel is a compromise
        between the need of a large field of view and high
        spatial resolution.
      • Filters, dispersers and polarizers  narrow and broad
        band imaging, low resolution (R ~ 100-500) slitless
        spectroscopy and imaging polarimetry.
      • Single CCD detector optimized for the UV wavelength
        range.

Leicester, December 3-5 2007                 WSO Detector Workshop
                               UVO CCD
      • CCD device back illuminated with AR coating
        optimized in the UV range.
      • 4k  4k pixels
      • Pixel size will 15 m square
      • Exposures will be split in sub exposures with
        integration times ≤ 15-20 minutes (due to
        cosmic ray contamination)  requirement on
        the dark current rate of 20 e–/pix/hr.

Leicester, December 3-5 2007             WSO Detector Workshop
 Quantity
                                             E2V CCD231-84
                                                 Required          Goal

 Pixel size                                      15    x      15   15    x      15
                                                 microns           microns

 Array Size                                      4096 x 4096       4096 x 4096
                                                 pixels            pixels

 Package size                                    70  mm        x   65mm          x                 QE: -100°C e2v Typical QE Astronomy Process with UV coating
                                                 70mm              65mm                   100%

 Surface Flatness (peak to valley)                20               20                   90%

                                                                                          80%
 Dark current rate, e–/pixel/hour                 20               15                   70%

                                                                                          60%
 Readout Noise @ 200 kHz     (e–    rms)         4.0               3.0




                                                                                     QE
                                                                                          50%

 Linearity over 70% of full well capacity        1.0%             0.1%                  40%

                                                                                          30%
 Full Well Capacity (image area), electrons      275000            350000
                                                                                          20%
 Full Well Capacity (register area), electrons   850000            850000
                                                                                          10%

 Wavelength Range                                200 – 700 nm      200 – 900 nm            0%
                                                                                             200    300      400       500      600        700    800      900   1000
 DQE Stability over 1 month (peak to peak)       5.0%              1.0%                                                      Wavelength (nm)


 Charge Transfer Efficiency (Parallel &           0.999990         0.999995
 Serial)

 Flat Field Non-uniformity Limit (1)             5.0%             3.0%
                                                                                     UVO channel CCD detector
 Flat Field Stability Limit, peak-to-peak over   1.0%              0.5%              preliminary functional
 one month
 Black & White Spots (pixels)                    800              400              requirements
 Maximum number of Column Defects                5                0

 Traps                                           10               5

 Operating Temperature, C                       –952             –952


Leicester, December 3-5 2007                                                                                        WSO Detector Workshop
       UVO detector package assembly
                               (preliminary design)
                                         Main components will be:
                                         a baseplate.
                                         • a mounting support for the CCD
                                         • the CCD detector
                                         • a cover
                                         • a flat quartz window and optical baffles.
                                         The baseplate will have holes for
                                         connectors and will host getter pumps to
                                         provide long term pumping against
                                         residual outgassing products.
                                         There will be no FEE inside the package
                                         assembly. The FEE will be accommodated
                                         on the backside of the baseplate. Hermetic
                                         feedthroughs connectors will ensure
                                         electrical continuity between the CCD and
                                         the FEE PCB/ASIC.
Leicester, December 3-5 2007                           WSO Detector Workshop
                               CCD Readout
                                           Full Frame Readout Time
                                                     (sec)

                                Outputs   100 kHz    200    500kHz
                                                     kHz
                                  1        168       84        32
                                  2         84       42        16
                                  4         42       21        8




                                   Operative modes:
                                   • Windowing: selection of a set of fixed sub-array
                                   apertures and user-defined sub-arrays
                                   • Binning: 2x2, 3x3, 4x4
                                   • Gain: to fully exploit the CCD well capacity the
                                   controller must allow the selection of different
                                   gains                       WSO Detector Workshop
Leicester, December 3-5 2007
        UVO CCD electronics system
 Timing Board: Commands
 CCD exposures. Generates TTL
 level clocks for the CCD timing
 pattern. Generates biases digital
 data.
 • Clock Driver: translate the
 TTL level clocks to CCD clock
 voltages and send them to the
 CCD.
 • Bias Generator / Analog
 Signal Processing: translate
 the biases digital data
                                      Low Noise Preamps: receive the signal
 generating the bias voltages to
                                     from each of the CCD outputs and send it to
 operate the CCD. Digitize the
                                     the analog signal processing board.
 signal from the CCD outputs to
 16-bit accuracy.
Leicester, December 3-5 2007                            WSO Detector Workshop
             Requirements for NUV&FUV
                     detectors
      Parameter                FUV               NUV
      Array size               2048x2048         2048x2048
      Active area             40 mm             40 mm
      Pixel size               20 µm             20 µm
      Spectral range           115-190 nm        150-280 nm
      QE                       > 20%@130 nm    > 10%@180 nm
                               <1.e-5%@≥400nm <0.1%@≥400nm
      Time resolution          ≤20 ms            ≤20 ms
      LDR                      ≥20 counts/s      ≥20 counts/s
      GDR                      ≥2*105 counts/s   ≥2*105 counts/s


Leicester, December 3-5 2007                      WSO Detector Workshop
      Some considerations on detector
                  choice

      • Directions from the science team: the more
        important characteristic is the spatial
        resolution (in particular for the NUV)
      • Very short WSO schedule: no R&D
      • Looking for something available now. Delivery
        time should fit the schedule
      • Avoid (if possible) ITAR

Leicester, December 3-5 2007           WSO Detector Workshop
       Baseline configuration of the UV
                  detectors
      • PC-ICCD

           – Photocathode
           – 2-3 stages MCP
             intensifier
           – Phosphor screen
           – Fiber Optic taper
           – High speed CCD
             camera
           – Real time digital
             electronics unit



Leicester, December 3-5 2007     WSO Detector Workshop
                  FUV & NUV Detectors


         FUV & NUV Channel: MCP-based
         detector in sealed configuration
         Format: 2kx2k (40mm)
         Read-out system: CCD
         Photocathodes: CsI (FUV), Cs2Te
         (NUV)




Leicester, December 3-5 2007                WSO Detector Workshop
                               Photek 40 mm




Leicester, December 3-5 2007              WSO Detector Workshop
                               MCP intensifier

      •   MCP                               2-stages (Chevron)
      •   Diameter                          40 mm
      •   Pore size                         10 m (12 m)
      •   L/D                               I 50:1
                                            II 80:1
      •   Gain                              5•105 e-
      •   Pulse Height Distribution (PHD)   <125% FWHM

      •   PHD spatial variation             <10% peak-to-peak
      •   Dark Counts @ 20C                <1 counts/cm2s
      •   Photocathode                      CsTe/CsI
      •   Window                            MgF2
      •   Phosphor screen                   P46
      •   Sealed configuration

Leicester, December 3-5 2007                       WSO Detector Workshop
                               Photocathodes




Leicester, December 3-5 2007              WSO Detector Workshop
                        CsI Photocathode

                                                          10,0
                                                           9,0
                                                           8,0
                                                           7,0




                                                   QE %
                                                           6,0
                                                           5,0
                                                           4,0
                                                           3,0
                                                           2,0
                                                           1,0
                                                           0,0
                                                              120 140 160 180 200 220
                                                                   W/length nm


 DQE for the CsI coated ACS SBC MCP                                Photek data


                               Semitrasparent vs opaque photocathode



Leicester, December 3-5 2007                                        WSO Detector Workshop
                    CCD Readout sensor
      Sarnoff VCCD-512
      •   Format                              512 x 512 pixels
      •   Pixel size                          18 x 18 m2
      •   Architecture                        Splitted FT
      •   Full well                           240,000 e-
      •   Fill factor                         100%
      •   N. of output Ampl.                  16
      •   Readout frequency                   10 MHz (per
          amplifier)
      •   Frame rate                          500 frames/s
     Require:
          • 4x centroid subpixel resolution


Leicester, December 3-5 2007                                     WSO Detector Workshop
          PC-ICCD Electronics Overview
 The detector electronics include two main
 blocks:
      an Analog Front-End Electronics
      (AFEE), an high speed front-end CCD
      electronics
      a Digital Front-End Electronics
      (DFEE) with a real time data
      processing unit, which will acquire the
      data from the CCD camera, search for
      the photon events and computes the
      coordinates of the detected photons
      with sub-pixel accuracy
 Filters for the High Voltage Power Supply
 should also be located close to the
 detectors.                                        ICU
Leicester, December 3-5 2007                    WSO Detector Workshop
               DFEE: data processing and
                      centroiding
      The DFEE will acquire serially the CCD digitized output signals + sync signals
      (frame, line and pixel sync), reorder them (if required), and subdivide the frame in
      sub-regions to be analyzed by parallel processors, each one implementing the
      following tasks:
                 –      through a proper system of delays, the processor will generate
                        33 pixel windows that sweep dynamically the whole matrix to be
                        analyzed at the pace of the pixel clock;
                 –      on each window:
                           •    check, according to appropriate discrimination and pile-up
                                rejection criteria, for the presence of a charge distribution
                                representing a photon event;
                           •    compute the centroid coordinates with a centre of gravity
                                algorithm to the charge distribution in the current window and
                                correcting for systematic errors.

       All the operations should be done in real time  no limits should be
       introduced by the electronics on the dynamic range
        implementation in FPGA, adopting a pipeline architecture in order to
       process the data at the rate they are generated by the sensor

Leicester, December 3-5 2007                                         WSO Detector Workshop
                         System Overview




Leicester, December 3-5 2007         WSO Detector Workshop
                                        Local Dynamic Range
                                                                                                                      DQE vs count rat e
                                                Dy namic resp onse
                                                                                          1
                      500


                      450
                                                                                         0.9
                      400


                      350                                                                0.8


                      300
       counts/s out




                                                                                         0.7




                                                                                   DQE
                      250


                      200                                                                0.6


                      150
                                                                                         0.5
                      100


                       50                                                                0.4

                       0
                            0       100           200            300   400   500
                                                                                         0.3
                                                                                                                                              1 10
                                                     counts/s in                                                                                      3
                                                                                               1                 10                     100
                                Linear respon se                                                                             counts/s
                                single/double as single
                                                                                                   single/double as single
                                single/double
                                                                                                   single/double
                                single
                                                                                                   single




Leicester, December 3-5 2007                                                                                      WSO Detector Workshop
       LDR translated to magnitudes …
Low limit:
Magnitudes giving SNR 10 on 3600 s (only source counts statistics is considered)
                  O3V     O5V     O6V     O8V     B0V     B3V     B5V     B8V     A0V     A5V     F0V     F5V     G0V     G5V     K0V     K5V     M5V
   FUV F122M     25.8    25.7    25.6    25.3    25.3    24.1    23.1    22.0    19.8    16.4    14.2    11.6     9.1     7.9     6.2     5.3     5.3
  FUV F130LP     28.1    28.0    27.8    27.6    27.6    26.6    26.0    25.3    23.9    21.4    19.8    17.8    15.5    14.4    12.3     6.9     6.4
   FUV F157W     26.4    26.3    26.2    26.0    26.0    24.8    24.1    23.3    21.7    18.8    16.6    13.8    11.2    10.0     7.8     5.5     5.5
  FUV F160BW     26.4    26.4    26.2    26.0    26.0    24.8    24.1    23.1    21.5    18.9    16.8    14.1    11.5    10.3     8.2     5.6     5.5
  FUV F165LP     26.3    26.2    26.1    26.0    26.0    24.9    24.2    23.5    22.4    21.3    19.7    17.1    14.6    13.5    11.3     6.2     6.0
   FUV F170W     26.6    26.6    26.4    26.3    26.3    25.1    24.5    23.6    22.3    20.4    18.5    15.9    13.3    12.1     9.9     5.8     5.7
   FUV Clear     28.9    28.8    28.7    28.5    28.5    27.3    26.5    25.6    24.0    21.8    19.9    17.4    14.8    13.7    11.5     6.3     6.1
   NUV F170W     26.1    26.0    25.9    25.8    25.8    24.7    24.1    23.3    22.2    21.2    19.9    18.2    16.6    15.8    14.0    10.5    10.2
   NUV F218W     25.7    25.7    25.6    25.5    25.5    24.5    24.0    23.3    22.3    21.8    21.0    19.9    18.8    18.0    16.0    11.6    11.2
   NUV F255W     25.0    25.0    24.9    24.8    24.8    24.0    23.5    22.8    21.9    21.5    20.9    20.2    19.5    19.0    17.9    14.0    13.4
   NUV Clear     28.7    28.7    28.6    28.4    28.4    27.4    26.8    26.1    25.1    24.5    23.8    23.0    22.2    21.7    20.6    16.8    16.1

 High limit:                                                                                                                                V Johnson
  Magnitudes giving 100 counts/s                   (PC-ICCD with 500 frames/s sensor)

                   O3V     O5V     O6V     O8V     B0V     B3V     B5V     B8V     A0V     A5V     F0V     F5V     G0V     G5V     K0V     K5V     M5V
     FUV F122M    16.9    16.8    16.7    16.5    16.5    15.2    14.3    13.1    10.9     7.5     5.3     2.7     0.2    -0.9    -2.7    -3.5    -3.5
    FUV F130LP    19.2    19.1    18.9    18.7    18.7    17.7    17.1    16.4    15.0    12.5    10.9     8.9     6.6     5.5     3.4    -2.0    -2.5
     FUV F157W    17.5    17.4    17.3    17.1    17.1    15.9    15.2    14.4    12.8     9.9     7.7     4.9     2.3     1.1    -1.1    -3.4    -3.4
    FUV F160BW    17.5    17.5    17.3    17.1    17.1    15.9    15.2    14.3    12.6    10.0     7.9     5.2     2.6     1.5    -0.7    -3.3    -3.4
    FUV F165LP    17.4    17.3    17.2    17.1    17.1    16.0    15.4    14.6    13.5    12.4    10.8     8.3     5.7     4.6     2.4    -2.7    -2.8
     FUV F170W    17.8    17.7    17.5    17.4    17.4    16.2    15.6    14.8    13.4    11.5     9.6     7.0     4.4     3.2     1.1    -3.1    -3.2
     FUV Clear    20.0    19.9    19.8    19.6    19.6    18.4    17.6    16.7    15.1    12.9    11.0     8.5     5.9     4.8     2.6    -2.5    -2.8
     NUV F170W    17.2    17.1    17.0    16.9    16.9    15.8    15.2    14.4    13.3    12.3    11.0     9.3     7.7     6.9     5.1     1.6     1.3
     NUV F218W    16.8    16.8    16.7    16.6    16.6    15.6    15.1    14.4    13.5    12.9    12.1    11.0     9.9     9.1     7.1     2.7     2.3
     NUV F255W    16.1    16.1    16.0    15.9    15.9    15.1    14.6    13.9    13.0    12.6    12.0    11.3    10.6    10.2     9.0     5.1     4.5
     NUV Clear    19.8    19.8    19.7    19.6    19.6    18.5    18.0    17.2    16.2    15.6    14.9    14.1    13.3    12.8    11.7     7.9     7.2


                                                 Range: 8.9 magnitudes
Leicester, December 3-5 2007                                                                                    WSO Detector Workshop
                  UV detectors data flux

                                                                    Mode 1:
                                            {x,y,t,A}     P
     MCP               A/D        Digital                           {x,y,t}
                                                                                          SDCU
                                                                                          SDMU
     Detector          FEE        FEE       Space
                                                                    Mode 2:
                                            wire          ICU       2Kx2K image
                                                                                  MIL-
                                            (> 80                                 1553B
                                            Mbps)
      The DFEE produces a 32-bit word for each detected photon, with the x,y,t
      coordinates (plus “amplitude”, used for monitoring). These words are sent, via
      Spacewire interface to the ICU. Operative mode (science + calibration) are
      (software) implemented in the ICU
      At least two operative modes (+windowing) will be implemented for science
      observations:
             1)    time tag mode: photon list {x,y,t} is sent to the SDCU and then to ground. Data
                   rate depends on the flux of incoming photons (which in turn depends on filters
                   and sources in the field)
             2)    accumulation mode: before sending them to the SDCU, counts are accumulated
                   by the ICU in an array in which each element correspond to a pixel, eventually
                   producing a CCD-like image  limit data rate by loosing time information,
                   allowing exposures with high count rate.

Leicester, December 3-5 2007                                          WSO Detector Workshop
            Model Philosophy (Moscow)
                                      Our proposal:
• WSO-UV plans                        • Bread Boards (not deliverable)
                                      • Structural Thermal Model
  – Full Scale Model – MSM              (deliverable, should be returned)
    (May 2008)                            – Optical Bench
          • Mass Model + Structural       – Mass dummies
            Model                         – Thermal dummies
     – Thermal Equivalent – TM        • Engineering Model (deliverable)
       (Jan 2009)                         – Mock-up optics and detectors
                                          – Functional representative of
     – Technological Model –                the flight model at Bus
       EM (Jan 2009)                        functional I/F level
     – Instrumentation Flight             – Optical Bench: Initially could
                                            be a plate to be replaced by
       Set Model – FM (May                  OB when performing EMC tests
       2009)                                or bus mechanical/functional
                                            integration tests.
                                      • Flight Model (deliverable)
Leicester, December 3-5 2007                     WSO Detector Workshop
Previous R&D on photon
   counting detectors
PC-ICCD for ground-
 based astronomy
          Window: quartz


        Photocathode: S20
          Photocathode         -2300 Volt
                               -2100 Volt
         MCP in
         MCPin                 -1400 Volt
         MCP out
         MCP out                   HV
                               Ground
         P20
         Phosphor Screen:
         Phosphor Screen
              P46              +5.5 KVolt

          Fiber Optic
          F.O.
             Faceplate
          Output Faceplate


              F.O. Optic
              Fiber Taper
              Taper: 2.4:1


                   CCD Array
                   CCD
                                                                               Data OUT
                   EEV CCD17

                                                                            FIFO Data
                                                                            Buffer
                                            Data Acquisition
                                            NI PCI-DIO32HS
                                                                  PC Host
                                            GPS                                           Camera Control
                                            DATUM BC635PCI



Leicester, December 3-5 2007                                   WSO Detector Workshop
               PC-ICCD characteristics
                           Array Size              2048  2048 pixel (1)
                                                   2048  512 pixel (2)
                           Pixel Size              13.5  13.5 m2

                           Spatial Resolution       25 m (FWHM) @ 550 nm
                                                    30 m (FWHM) @ 254 nm
                           Time Resolution         16.8 ms (1)
                                                   4.512 ms (2)
                           Detective Quantum       8.2%    @ 229 nm
                           Efficiency (DQE)        6.8%    @ 254 nm
                           Visible Light DQE       0.074% @ 405 nm

                           Spectral Range (DQE    120-300 nm
                           1%)
                           Dark Count Rate         1.74 cts s-1cm-2

                           Local Dynamic Range     13 cts s-1 (1)
                           (DQE loss < 10 %)       54 cts s-1 (2)
                           Global Dynamic Range    2.6 104 cts cm-2 s-1    (1)
                           (DQE loss < 10 %)       9.2 104 cts cm-2 s-1    (2)



Leicester, December 3-5 2007                                               WSO Detector Workshop
                       Spatial Resolution




            Readout system:
             FWHMx~ 5 m                     Detector:
      Front MCP pore structure fully   FWHMx~ 25 m @ 5500Å
               resolved                limited by proximity focus


Leicester, December 3-5 2007                     WSO Detector Workshop
                                                      Dynamic Range
                     140        a)

                     120

                     100
                                                                                                   10% fractional count
               -




                     80                                    220 frames sec-1                          rate loss:
                     60
                                                                                                   Local:
                 O




                     40
                                                   60 frames sec-1
                     20
                                                                                                   • 13 cts/s @ full frame
                      0


                                                                                                   • 54 cts/s @ window
                           0             50           100            150              200
                                                  Input Counts sec-1




               3.0·10 5
                               b)

               2.5·10 5
           -




               2.0·10 5
           -




                                                           220 frames sec-1
               1.5·10 5
                                                                                                   Global:
               1.0·10 5
                                                     60 frames sec-1                               • 2.6·104cts cm-2 s-1
           O




               5.0·10 4


                      0
                           0         1.0·10 5     2.0·10 5 3.0·10 5        4.0·10 5     5.0·10 5
                                                                                                   • 9.2·104cts cm-2 s-1
                                                Input Counts cm-2 sec-1


Leicester, December 3-5 2007                                                                                   WSO Detector Workshop
                        Asiago-Cima Ekar
                               • 182 cm Telescope + AFOSC (3 filter
                               wheels allowing combination of:
                               photometric filters, grisms, Echelle
                               grisms, polarimeter based on a double
                               Wollaston prism)
                                High speed Photometry &
                               spectroscopy of CV & Flare stars




Leicester, December 3-5 2007                   WSO Detector Workshop
                               Crab Pulsar


                                       •PFFT=0.0334881±1.5·10-7 s


                                       •PEF=0.033488256±8·10-9 s




Leicester, December 3-5 2007                 WSO Detector Workshop
                    1WGA 1958.2+3232




                               eioor m
                                r dga
                                                   S1
                                         30
                                         25
                                         20                       0.1%
                                         15                       10%
                                         10
                                          5




                               P
                                          0
                                           0   5           10            15
                                                   mHz

                                                   S3
                                         30

                                         20
                                                                  10%
                                         10




                               P
                                          0
                                           0   5           10            15
                                                   mHz

                                                   S7
                                         30

                                         20
                                                                  10%
                                         10
                               P




                                          0
                                           0   5           10            15
                                                   mHz




Leicester, December 3-5 2007                             WSO Detector Workshop
                               PC-IAPS
                                Objective Holder


                                Light Tight
        HV
     Connecto
     r                           CMOS - APS

      MCP




  Lens                           Electronic Board
  Objective



                                                           1024x1024 pixel
                                                           1024 8-bit ADC on
                                                           chip (one for each
                                                           column)
                                                           8 parallel outputs
                                                           Up to 500 frame/s
                                                           full frame
                                                           (+windowing)
Leicester, December 3-5 2007                        WSO Detector Workshop
                      PC-IAPS FEE Board


                                 The APS is mounted on a 10 cm
                                 x 10 cm PCB board, which also
                                 hosts the driving electronics, the
                                 real time data processing unit
                                 and the interfaces to the host
                                 PC. The core of the electronics is
                                 a single FPGA, XILINX XCV 800
                                 (800 Kgates equivalent),
                                 allowing a very compact design.




Leicester, December 3-5 2007            WSO Detector Workshop
                 PC-IAPS FEE Overview
     • At each clock pulse, the 64 bits data output (8 pixels x 8-bit) are acquired by the
     data processor.
     • Synchronous FIFO are used as delay line that allows a concurrent sampling of a
     pixel together with its nearest neighbors.
     • Upon initialization, a set of D-Latches is used to map 8 windows of 3x3 pixels,
     which covers dynamically the whole APS image at the pace of the pixel clock. This
     allows the whole APS frame to be analyzed, avoiding problems of either fixed or
     dynamic image partitioning.
     • The processing system performs in parallel the following tasks on each window:


                                                             Check (discrimination and pile-up
                                                            rejection criteria) for the presence of
                                                            a photon event;
                                                             compute the centroid coordinates
                                                            and transfer them to a PC.




Leicester, December 3-5 2007                                      WSO Detector Workshop

								
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