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M. Bonesini INFN Milano

TOF status (mainly TOF0/1). M. Bonesini INFN Milano. Outline. TOF2 (brief summary) upstream TOF (TOF0/1) Costs updates TOF0 design TOF1 design (PMT shielding) BTF testbeam Conclusions. TOF2 (brief summary).

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M. Bonesini INFN Milano

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  1. TOF status (mainly TOF0/1) M. Bonesini INFN Milano M. Bonesini - MICE Collaboration Meeting 9/10/06

  2. Outline • TOF2 (brief summary) • upstream TOF (TOF0/1) • Costs updates • TOF0 design • TOF1 design (PMT shielding) • BTF testbeam • Conclusions M. Bonesini - MICE Collaboration Meeting 9/10/06

  3. TOF2 (brief summary) • project is a clone of upstream TOF0/1 design, aside dimensions (it was 48 x 48 cm2 now …) • funds NOT requested to INFN for 2007: it will be staged to 2008 • but it may be put together KLOE1 as a preshower, giving a lot of savings (discussions are going on with Ludovico). In this way a TOF2 in 2007 with recuperated PMTs … to be updated in 2008 (TOF2A). M. Bonesini - MICE Collaboration Meeting 9/10/06

  4. Upstrean TOF0/TOF1: revised costs M. Bonesini - MICE Collaboration Meeting 9/10/06

  5. CAVEAT: prototyping, in-house manpower, lab test expenses and small consumables excluded M. Bonesini - MICE Collaboration Meeting 9/10/06

  6. FUNDS were requested for TOF0/1 from Mi Bicocca and Pavia groups to INFN for 2007 (~250 KEuro) • not yet granted (but situation seems hard): for commissione V MICE does not exist for 2007 and at best they may come randomly • 2006 funds (only for Milano) cover prototyping work + BTF testbeam+ partially TOF0 (really they were allocated for prototyping work NOT construction) • all has influence on schedule: that is budget-bound not technically-bound (clearly NOW on a best effort base) • The arrival of some new group (that can help partially INFN funding of TOF+MUCAL) can help much situation also with INFN management M. Bonesini - MICE Collaboration Meeting 9/10/06

  7. TOF0/1 design • mechanics+counters: defined aside dimensions for TOF1 (reduce them from 48x48 cm2 to 42x42 cm2 if possible). TOF1 counter width defined as 6 cm. • 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 Collaboration Meeting 9/10/06

  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 Collaboration Meeting 9/10/06

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

  10. B field is ~ 200 G //; ~ 1000 G _|_ M. Bonesini - MICE Collaboration Meeting 9/10/06

  11. Problem: R4998 can bare B_|_ but not B// B//< 50 Gauss fine; B_|_ < 100-120 Gauss fine add soft iron PMTs shielding M. Bonesini - MICE Collaboration Meeting 9/10/06

  12. B field with 2 iron shields sandwiching TOF (100 mm gap) PMTs will be put at ~ 33-35 cm M. Bonesini - MICE Collaboration Meeting 9/10/06

  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 Collaboration Meeting 9/10/06

  14. B-field for different gaps Br M. Bonesini - MICE Collaboration Meeting 9/10/06

  15. Scanning the gap: Near 100 mm shielding M. Bonesini - MICE Collaboration Meeting 9/10/06

  16. Scanning the gap II near 10 mm shielding center Remember: TOF1 PMTs volume will be inside a +- 25 mm box from gap center M. Bonesini - MICE Collaboration Meeting 9/10/06

  17. 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 Collaboration Meeting 9/10/06

  18. B_r -- 500 gauss B_z 500 gauss G. Gregoire scheme gives very effective shielding for TOF1/2 M. Bonesini - MICE Collaboration Meeting 9/10/06

  19. 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 Collaboration Meeting 9/10/06

  20. 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 Collaboration Meeting 9/10/06

  21. 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 measures (t_L-t_R): left start, right stop M. Bonesini - MICE Collaboration Meeting 9/10/06

  22. MCA Maestro analysis • data were analized online with the MAESTRO program (WINDOWS based) and later they were reanalized offline. • You can measure only counter intrinsic resolutions, without corrections for time-walk. M. Bonesini - MICE Collaboration Meeting 9/10/06

  23. Comparison MCA analysis-PAW reanalysis Left is BC420 re-analized data, next slide the original MCA Maestro data st~56 ps M. Bonesini - MICE Collaboration Meeting 9/10/06

  24. st ~ 50 ps M. Bonesini - MICE Collaboration Meeting 9/10/06

  25. 4cm width bars: UPS95F st~56 ps st~50 ps Lightguide is a Winston cone Lightguide is fishtail M. Bonesini - MICE Collaboration Meeting 9/10/06

  26. 4cm bars: BC420 st~56 ps st~ 63 ps Lightguide fishtail BC800 Lightguide fishtail REPSOL glass M. Bonesini - MICE Collaboration Meeting 9/10/06

  27. 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 Collaboration Meeting 9/10/06

  28. Position scan along a BC420 bar • resolution is worse at the edges probably due to the PMT rough gain calibration (but still ~ 60 ps) • x=0 cm is the edge of the bar, x=20 cm the center M. Bonesini - MICE Collaboration Meeting 9/10/06

  29. Conclusions for fast MCA analysis • BC420 scintillator seems more than adequate, but also low-cost UPS95F or BC404 are valid alternatives • no gain from complicate lightguide design (Winston cone) as respect to simple fish-tail one • Resolution with FAST conventional PMTs (R4998) seems better than with 1” fine-mesh PMTs • results depend heavily on BTF beam instabilities, but intrinsic counter resolution is fine ~60 ps. M. Bonesini - MICE Collaboration Meeting 9/10/06

  30. 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 Collaboration Meeting 9/10/06

  31. 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 Collaboration Meeting 9/10/06

  32. PMT left scintillator PMT right TOF bar In all the following transparencies from Yordan+Roumen with some annotations by me electron beam finger 1 Bar 1 Bar 2 Bar 3 finger 2 M. Bonesini - MICE Collaboration Meeting 9/10/06

  33. 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 Collaboration Meeting 9/10/06

  34. 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 Collaboration Meeting 9/10/06

  35. Intrinsic time resolution of TOF bars Run 124 – 133 Distributions of (Tleft – Tright )/2 TDC V1290 Discr CAEN N417 Bicron BC420 - 4cm thick impact point at 15 cm from center (5 cm from edge) σ = 72.73 ps Bicron BC420 - 4cm thick impact point at center σ = 64.91 ps Bicron BC408 - 6cm thick impact point at center σ = 107.2 ps M. Bonesini - MICE Collaboration Meeting 9/10/06

  36. 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 Collaboration Meeting 9/10/06

  37. CAEN V1290 vs CAEN V775 • resolution with V775 TDC seems even better than with MCA analysis (41 ps) • but from CAEN team intrinsic resolution of V1290 is 35 ps as compared to 28 ps of V775 (we have to understand the difference) M. Bonesini - MICE Collaboration Meeting 9/10/06

  38. 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 Collaboration Meeting 9/10/06

  39. 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 Collaboration Meeting 9/10/06

  40. Time Of Flight and Time-walk effect Run 124-133 M. Bonesini - MICE Collaboration Meeting 9/10/06

  41. Conclusions • we need to finalize TOF1 size: guess 42 x 42 cm2 instead of 48 x 48 cm2 • 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 • schedule $-bound M. Bonesini - MICE Collaboration Meeting 9/10/06

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