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M. Bonesini INFN Milano

TOF upstream PID review (TOF0/1). M. Bonesini INFN Milano. Outline. upstream TOF (TOF0/1 Costs updates Mechanics TOF0 design TOF1 design (PMT shielding) BTF testbeam Conclusions. Upstream TOF0/TOF1: revised costs. CAVEAT: prototyping, in-house manpower,

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M. Bonesini INFN Milano

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  1. TOF upstream PID review (TOF0/1) M. Bonesini INFN Milano M. Bonesini - MICE PID review 12/10/06

  2. Outline • upstream TOF (TOF0/1 • Costs updates • Mechanics • TOF0 design • TOF1 design (PMT shielding) • BTF testbeam • Conclusions M. Bonesini - MICE PID review 12/10/06

  3. Upstream TOF0/TOF1: revised costs M. Bonesini - MICE PID review 12/10/06

  4. CAVEAT: prototyping, in-house manpower, lab test expenses and small consumables excluded M. Bonesini - MICE PID review 12/10/06

  5. Some workouts on costs: • main question mark is electronics: L.E. discriminators vs CF discriminators, need to correct time-walk • reductions: • Cheaper laser calibration system • Cheaper PMTs for TOF1 • Counters: in-house machining of lightguides M. Bonesini - MICE PID review 12/10/06

  6. TOF0/1 global design • mechanics+counters: defined TOF0 40x40 cm2, TOF1 42X42 cm2 or less. Segmentation 4cm (6 cm) TOF0 (TOf1). X/Y geometry: redundancy+cross calibration with muons • PMTs: we advocate (with some caveats) same choice for TOF1 and TOF0 (see later) • FE electronics: • TDC V1290 seems valuable choice, but needs interactions with CAEN • discriminators: under study, we have to finalize BTF analysis + possibly some tests with a cosmics testbench in Milano (LE vs CF) • Time walk correction: needs to finalize BTF testbeam study, to see if it is really needed: if so extra costs for QADC M. Bonesini - MICE PID review 12/10/06

  7. General design of mechanics: • 2 X/Y layers • Good to increase st • Good for detector intercalibration M. Bonesini - MICE PID review 12/10/06

  8. Conventional PMTs shielding • TOF0 PMTs requires no shielding, aside 1 mm m-metal due to small B field (B << 50 Gauss, Kevin private communication) • TOF1/2 even after the 100 mm global iron shielding needs some additional shielding to use conventional PMTs (as B// ~ 200 Gauss, B _|_ ~.1 T) M. Bonesini - MICE PID review 12/10/06

  9. B field with one 100 mm iron shield (current design) M. Bonesini - MICE PID review 12/10/06

  10. B field is ~ 200-300 G //; ~ 1000 G _|_ at r=30-35 cm (PMTs position) • I doubt it can be shielded with individual PMTs shields, preserving good timing properties • this point to 2nd shield, but we will try to test PMTs “exotic shieldings” bybuilding a 400 G lab solenoid M. Bonesini - MICE PID review 12/10/06

  11. Problem: R4998 can bare B_|_ but not B// B//< 50 Gauss fine; B_|_ < 100-120 Gauss fine with present m-metal shielding add soft iron PMTs shielding M. Bonesini - MICE PID review 12/10/06

  12. B field with 2 iron shields sandwiching TOF (100 mm gap) PMTs will be put at ~ 33-35 cm M. Bonesini - MICE PID review 12/10/06

  13. B// ~ 40 Gauss, B_|_ ~ 1200 Gauss • Problem: B-field perturbation from individual PMTs shielding has not been simulated: this implies a 3-D calculation • Valuable option to be finalized (conventional PMTs cheaper + better performances) M. Bonesini - MICE PID review 12/10/06

  14. B-field for different gaps Br M. Bonesini - MICE PID review 12/10/06

  15. G. Gregoire Shield From presentation by G. Gregoire at PC-224 and J.Cobb at PID // session  Close outer gap between to discs; thicker 2nd disc (50mm) Somewhat more complex – engineering / mounting TOFs…. M. Bonesini - MICE PID review 12/10/06

  16. B_r -- 500 gauss B_z 500 gauss G. Gregoire scheme gives very effective shielding for TOF1/2 M. Bonesini - MICE PID review 12/10/06

  17. Conclusions for TOF1 PMTs • use of conventional PMTs with ~1 mm m-metal shielding + additional 10/50 mm global iron shield (Jon&Holger original proposal or modified G. Gregoire one) valuable option for TOF1 • Better timing • Much lower cost (factor 2) and guaranteed production from Hamamatsu • Same PMTs all around • Needs mounting of PMTs at r>30-33 cm: this is fine for present design (TOF1 48 x 48 cm2), but if we reduce dimensions of TOF1 (say TOF1 42x42 cm2) needs revised design of lightguides (longer ones). NO REAL PROBLEM. • Bad: some extra work for additional global shielding, it may be integrated in TOF1 support structure But need a 3-D field computation to check perturbation from PMTs individual shielding on B field M. Bonesini - MICE PID review 12/10/06

  18. The BTF testbeam • Testbeam at BTF for 12 days in July 06 • Data taken both with MCA (fast analysis) and full DAQ setup (full analysis) • We have tested TOF resolutions, not rate effects (for this we can do only lab tests with our laser system) and some items of FE electronics M. Bonesini - MICE PID review 12/10/06

  19. PMT left scintillator PMT right TOF bar MCA Ortec Trump 8K Discr PLS711 electron beam finger 1 Bar 1 Bar 2 Bar 3 finger 2 TAC Ortec 566 TAC or DAQ M. Bonesini - MICE PID review 12/10/06

  20. st ~ 50 ps M. Bonesini - MICE PID review 12/10/06

  21. 4cm width bars: UPS95F st~56 ps st~50 ps Lightguide is a Winston cone Lightguide is fishtail M. Bonesini - MICE PID review 12/10/06

  22. 4cm bars: BC420 st~56 ps st~ 63 ps Lightguide fishtail BC800 Lightguide fishtail REPSOL glass M. Bonesini - MICE PID review 12/10/06

  23. 6cm bars: BC404, BC420, BC408 st~45 ps st~46 ps BC-404 / BC-420 seem equivalent, BC-408 (as expected) worse st~60 ps Long non-gaussian tails M. Bonesini - MICE PID review 12/10/06

  24. Preliminary results From DAQ analysis • more complete check: you test also used TDC (CAEN V1290), used discriminators in real TOF measure, time-walk effects … • ROOT files from JS analyzed by Yordan and Roumen + some hints from MB • results still preliminary (some data sets not yet analyzed) M. Bonesini - MICE PID review 12/10/06

  25. Taken data: • data taken with 3 bars of different type • data taken with different discriminators: L.E. CAEN N417, L.E. PLS 711, CF ORTEC 8000 • data taken with different TDC: CAEN V1290, CAEN V775 • QADC data (for time-walk corrections) available M. Bonesini - MICE PID review 12/10/06

  26. ADC pulse height distribution (left PMT of bar 1) Example of the general event selection cut ADC spectrum in logarithmic scale Selection of single electron events Part of the same spectrum in linear scale M. Bonesini - MICE PID review 12/10/06

  27. Intrinsic time resolution of TOF bars Run 141 – 149 Distributions of (Tleft – Tright )/2 TDC V1290 Bicron BC420 - 4cm thick impact point at 10cm from Center Discr CAEN N417 σ = 63.91 ps Bicron BC420 - 4cm thick impact point at center Discr CAEN N417 σ = 66.18 ps Bicron BC408 - 6cm thick impact point at center Discr CAEN N417 σ = 109.7 ps M. Bonesini - MICE PID review 12/10/06

  28. Intrinsic time resolution of TOF bars Run 215 – 217 Distributions of (Tleft – Tright )/2 TDC V1290 Bicron BC420 - 4cm thick impact at center Discr PLS 711 σ = 44.22 ps Bicron BC420 - 4cm thick impact point at center Discr PLS 711 σ = 97.16 ps (PROBLEMS IN PMTs EQUALIZATION) Bicron BC404 - 6cm thick impact point at center Discr PLS 711 σ = 49.21 ps M. Bonesini - MICE PID review 12/10/06

  29. TOF between two bars We expect 85 ps from 60 ps single counter resolution , we see 140 ps Houston we have A problem (from WEB: originally reporting of a life threatening fault. Now humorously used to report ANY problem). Remind TOF is double-plane (X/Y) so 80 ps means in reality 60 ps for real life MICE TOF measurements M. Bonesini - MICE PID review 12/10/06

  30. A first hint: time-walk Cut=0; 135 ps • Side plots point to a jitter/ time-walk problem of used discriminators • needs to check with further testbeam data (with CF discriminator) • requires some lab tests on discriminator Cut=.25 ; 125 ps Cut=.10; 91 ps M. Bonesini - MICE PID review 12/10/06

  31. Time Of Flight and Time-walk effect Run 124-133 M. Bonesini - MICE PID review 12/10/06

  32. Conclusions • no foreseen problems for mechanics • we advocate use of conventional PMTs for TOF1 + global shielding (G. Gregoire design ?) • BTF analysis in course points to good intrinsic counter resolution, reasonable behaviour of V1290 TDC, but requires to think about discriminators/time walk corrections • TRD will be updated soon (MICE Note 145+ BTF testbeam results) • up to now upstream PID TOFes in schedule (delays may come from funding) M. Bonesini - MICE PID review 12/10/06

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