1. A2 collaboration meeting Feb 2011, Peter-Bernd Otte A2 Collaboration Meeting Feb 2011 – Peter-Bernd Otte Status New Trigger & Beam Polarimetry polarised foil

2. A2 collaboration meeting Feb 2011, Peter-Bernd Otte Brevity is the soul of wit FPGA ~3 cm ~ meters = semiconductor chip FPGA = many electronics modules (like OR, MLU) cables no CPU! “VUPROM” from GSI with “Virtex 4” from XILINX

3. A2 collaboration meeting Feb 2011, Peter-Bernd Otte Part A: New Experiment Trigger Setup of New Trigger CB PID 1 st stage VUPROM level converter & cable master VUPROM cables Exp. trigger 70ns Computation time: 460ns for Multiplicity (LT = 98.7%) 20ns for Coplanarity (LT = 100%) Computation time: 460ns for Multiplicity (LT = 98.7%) 20ns for Coplanarity (LT = 100%) Cellular Cluster Counter

4. A2 collaboration meeting Feb 2011, Peter-Bernd Otte Part A: New Experiment Trigger cellular logic Steps 1.gather hit pattern (330ns) 2.Shrink clusters (60ns) (using set of rules) until no more changes 3.Count number of cells (20ns) = number of clusters 4.If desired cluster count  trigger! Multiplicity cluster algorithm crystal scheme of CB

5. A2 collaboration meeting Feb 2011, Peter-Bernd Otte Part A: New Experiment Trigger Algorithm universality + 180° rotatedtogether 6x Not all rules are valid for all crystals at all times. 12 3 1 5 2 3 1 4 2 3 1 4 5 2 3 1 5 10 6 2 3 +120° & +240° rotated cure wholes Shrink CBTAPS together 6x

6. A2 collaboration meeting Feb 2011, Peter-Bernd Otte Part A: New Experiment Trigger Future New CB trigger works since several months in parallel to the existing one awaits integration into L1/L2 Remaining: purity and efficiency? More sophisticated triggers possible with: CB, PID, TAPS, MWPC in combination for L1/L2

7. A2 collaboration meeting Feb 2011, Peter-Bernd Otte Part B: Beam polarimetry e - beam polarimetry Tagger e-e- radiator Measure degree of e- beam polarisation using Moeller polarimeter Good news: No big energy shift anymore! now correct calibration for “new Tagger” only ~1ch due to optics

8. A2 collaboration meeting Feb 2011, Peter-Bernd Otte Part B: Beam polarimetry e - beam polarimetry works, but: mark “C” long. degree of polarisation in %

9. A2 collaboration meeting Feb 2011, Peter-Bernd Otte Part B: Beam polarimetry 100 histograms/FPGA, here 2 samples Reason: detector. Proof: measured with two different electronics shaky measurements time diff. /ch low hummingStrong humming = =

10. A2 collaboration meeting Feb 2011, Peter-Bernd Otte Part B: Beam polarimetry I5 and P7 channels of tagger: Humming = leads to biggest uncertainty in Moeller Humming in Tagger (no noise!)

11. A2 collaboration meeting Feb 2011, Peter-Bernd Otte Part B: Beam polarimetry Why not constant? e- source flux normalisation Tagger section A B C D E F G H I J K L M N O P  ~3% in pol. degree

12. A2 collaboration meeting Feb 2011, Peter-Bernd Otte Part B: Beam polarimetry 8 th Feb work on beam dump  dump position changed (?)  0.4% tagger magnet field change  0 to 2 channels shift in Tagger  change in Moeller electronics and analysis needed Polarisation bit  beam polarisation – possible to be obtained – MAMI energy dependent Beam polarimetry

13. A2 collaboration meeting Feb 2011, Peter-Bernd Otte Part B: Beam polarimetry 5 VUPROMs in Tagger rack = 1.Moeller electronics 2.planned as monitor for linear photons polarisation: indep. Tagger scalers with pair spectrometer as gate  Patrik's talk 3.selection of single tagger channels for tests Electronics in Tagger area old

14. A2 collaboration meeting Feb 2011, Peter-Bernd Otte Part C: Problems Problem in existing exp. trigger Start of TDC at „CB Energy Sum“ Stop of TDC at „TCS Trig“ / Exp. Trigger 1% unclear 300ns

15. A2 collaboration meeting Feb 2011, Peter-Bernd Otte A2 Collaboration Meeting Feb 2011 – Peter-Bernd Otte Status elog

16. A2 collaboration meeting Feb 2011, Peter-Bernd Otte http://elog.office.a2.kph (user: a2online) http://elog.office.a2.kph elog from PSI (Stefan Ritt), open source, widely used und known – Many people in our group can assist – No text losses and locks anymore – Data from existing elog has been imported Data reliability – uses infrastructure from KPH computing group – virtual computer with RAID 5 (+ remote hot mirror) and snapshots  paperless future Everybody or group can have his/their own logbook elog

17. A2 collaboration meeting Feb 2011, Peter-Bernd Otte Part C: Problems The all new keyboard New keyboard for all German PhD students. Makes life easier… K.T. zu Guttenberg, Minister of Defence “Wrote” >20% of his PhD with Thanks for listening!

18. A2 collaboration meeting Feb 2011, Peter-Bernd Otte Appendix

19. A2 collaboration meeting Feb 2011, Peter-Bernd Otte Part A: New Experiment Trigger Trigger = 2 hits in plane with incoming  (only azimuthal)   1 –  2| = 180 deg divide CB into 48 azimuthal bins “hardwired” trigger with ANDs and ORs immediate trigger result  Livetime = ~100% rate: 580Hz (while M1+ = 16k, M2+ = 3.6k) Coplanarity trigger direction of beam 24x sublogic OR AND  Simulation by Cristina Collicott (D. Hornidge)

20. A2 collaboration meeting Feb 2011, Peter-Bernd Otte Part A: New Experiment Trigger Measured: Azimuth angle difference between hit channels in CB Coplanarity trigger Number of clusters (M) determined by FPGA logic

21. A2 collaboration meeting Feb 2011, Peter-Bernd Otte Part A: New Experiment Trigger Setup of New Trigger: Multiplicity Trigger CB (NaI) PID 1 st stage VUPROM level converter & cable master VUPROM cables signal to all: Send full hit pattern Exp. trigger 70ns20ns15ns 310ns 100-120ns + Detailed hit pattern needed  full readout!

22. A2 collaboration meeting Feb 2011, Peter-Bernd Otte Rates: livetime: 98.7% Next step: determine purity and efficiency Same trigger algorithms can be extended to cover also TAPS Multiplicity Trigger: Rates New Trigger (CB only)Existing (CB and TAPS) M1+20k40k M2+4.5k6.0k M3+1.6k2.2k

23. A2 collaboration meeting Feb 2011, Peter-Bernd Otte Teil 2: Trigger-Logiken Bonn (2000)Mainz (2010) Geschwindigkeit (nur Berechnung) bis zu 10µs/Cluster120ns insg. LogikZellularer Aufbau aber sequentielle Bearbeitung Echt zellulare Logik Im Vergleich

24. A2 collaboration meeting Feb 2011, Peter-Bernd Otte Part B: Moeller Polarimeter Use Moeller scattering – measure 2 coincident electrons  DAQ necessary – Count asymmetry  beam polarity Introduction electron beam polarimetry polarised foil use Tagger

25. A2 collaboration meeting Feb 2011, Peter-Bernd Otte Detectors of Tagger Part B: Moeller Polarimeter Moeller radiator Tagger 4x VUPROMs Moeller Polarimeter Setup 1352 VUPROM 1 VUPROM 2 VUPROM 3 VUPROM 4 AB EF GH IJOP QR ST UV Complete DAQ on a chip. Per FPGA: 24x TDC (resolution 50ps) & 50 histograms

26. A2 collaboration meeting Feb 2011, Peter-Bernd Otte Part B: Moeller Polarimeter same e- energy and entry angle but different angles signs Simulate Moeller electrons (Tagger optics) Tagger chan. energy shift in MeV (450 MeV beam energy)

27. A2 collaboration meeting Feb 2011, Peter-Bernd Otte Part B: Moeller Polarimeter Sum of energy shift Simulate Moeller electrons (Tagger optics)