M Bonesini TOF status INFN Milano mainly TOF

M. Bonesini TOF status INFN Milano (mainly TOF 0/1) M. Bonesini - MICE Collaboration Meeting 9/10/06 1

Outline TOF 2 (brief summary) upstream TOF (TOF 0/1) n n Costs updates TOF 0 design TOF 1 design (PMT shielding) BTF testbeam Conclusions M. Bonesini - MICE Collaboration Meeting 9/10/06 2

TOF 2 (brief summary) project is a clone of upstream TOF 0/1 design, aside dimensions (it was 48 x 48 cm 2 now …) funds NOT requested to INFN for 2007: it will be staged to 2008 but it may be put together KLOE 1 as a preshower, giving a lot of savings (discussions are going on with Ludovico). In this way a TOF 2 in 2007 with recuperated PMTs … to be updated in 2008 (TOF 2 A). M. Bonesini - MICE Collaboration Meeting 9/10/06 3

Upstrean TOF 0/TOF 1: revised costs TOF 0 TRD design costs TOF 0 updated costs Conv. PMTs 64 KE mechanics 5 KE Scintillators+light guides 10 KE Scintillators+light guides 5 KE cables 3 KE Cables 3 KE Patch panels … 5 KE Laser syst (1/3) 22 KE Laser syst (1/3) 10 KE FE electronics (QADC+TDC+L. E. discr+ splitters) 25 KE FE electronics (TDC+CF discr) 18 KE HV voltage (1/3) 12 KE HV voltage (1/3) 9 KE Total 146 KE M. Bonesini - MICE Collaboration Meeting 9/10/06 119 KE 4

TOF 1 TRD design costs TOF 1 revised design PMTs fine mesh 87. 5 KE Conv. PMTs 52 KE mechanics 5 KE mechanics 8 KE Scintillators+light guides 10 KE Scintillators+light guides 5 KE cables 3 KE Cables 3 KE Patch panels … 5 KE Laser syst (1/3) 22 KE Laser syst (1/3) 10 KE FE electronics 25 KE (QADC+TDC+L. E. discr. +splitters) FE electronics (TDC) 18 KE HV voltage (1/3) 12 KE HV voltage (1/3) 9 KE Total 169 KE 110 KE CAVEAT: prototyping, in-house manpower, lab test expenses and small consumables excluded M. Bonesini - MICE Collaboration Meeting 9/10/06 5

q FUNDS were requested for TOF 0/1 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 TOF 0 (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 6

TOF 0/1 design mechanics+counters: defined aside dimensions for TOF 1 (reduce them from 48 x 48 cm 2 to 42 x 42 cm 2 if possible). TOF 1 counter width defined as 6 cm. PMTs: we advocate (with some caveats) same choice for TOF 1 and TOF 0 (see later) FE electronics: n n n TDC V 1290 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 7

Conventional PMTs shielding q TOF 0 PMTs requires no shielding, aside 1 mm m-metal due to small B field (B < 50 Gauss, Kevin private communication) q TOF 1/2 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 8

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

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

Problem: R 4998 can bare B_|_ but not B//< 50 Gauss fine; B_|_ < 100 -120 Gauss fine add soft iron PMTs shielding M. Bonesini - MICE Collaboration Meeting 9/10/06 11

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 12

• 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 13

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

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

Scanning the gap II center near 10 mm shielding Remember: TOF 1 PMTs volume will be inside a +- 25 mm box from gap center M. Bonesini - MICE Collaboration Meeting 9/10/06 16

G. Gregoire Shield From presentation by G. Gregoire at PC-224 and J. Cobb at PID // session Close outer gap between to discs; thicker 2 nd disc (50 mm) Somewhat more complex – engineering / mounting TOFs…. M. Bonesini - MICE Collaboration Meeting 9/10/06 17

B_r -- 500 gauss B_z 500 gauss G. Gregoire scheme gives very effective shielding for TOF 1/2 M. Bonesini - MICE Collaboration Meeting 9/10/06 18

Conclusions for TOF 1 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 TOF 1 n n n 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 (TOF 1 48 x 48 cm 2), but if we reduce dimensions of TOF 1 (say TOF 1 42 x 42 cm 2) needs revised design of lightguides (longer ones). NO REAL PROBLEM. Bad: some extra work for additional global shielding, it may be integrated in TOF 1 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 19

The BTF testbeam Energy range 25 -750 Me. V e-/e+ Max rep rate 50 Hz Pulse duration 10 ns Current/pulse 1 -1010 particles 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 20

PMT left scintillator PMT right TOF bar Discr PLS 711 electron beam MCA Ortec Trump 8 K finger 1 TAC Ortec 566 Bar 1 TAC measures (t_L-t_R): left start, right stop Bar 2 Bar 3 finger 2 M. Bonesini - MICE Collaboration Meeting 9/10/06 21

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 22

Comparison MCA analysis-PAW reanalysis st~56 ps Left is BC 420 reanalized data, next slide the original MCA Maestro data M. Bonesini - MICE Collaboration Meeting 9/10/06 23

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

4 cm width bars: UPS 95 F st~56 ps Lightguide is a Winston cone st~50 ps Lightguide is fishtail M. Bonesini - MICE Collaboration Meeting 9/10/06 25

4 cm bars: BC 420 st~56 ps Lightguide fishtail BC 800 st~ 63 ps Lightguide fishtail REPSOL glass M. Bonesini - MICE Collaboration Meeting 9/10/06 26

6 cm bars: BC 404, BC 420, BC 408 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 27

Position scan along a BC 420 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 28

Conclusions for fast MCA analysis BC 420 scintillator seems more than adequate, but also low-cost UPS 95 F or BC 404 are valid alternatives no gain from complicate lightguide design (Winston cone) as respect to simple fish-tail one Resolution with FAST conventional PMTs (R 4998) 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 29

Preliminary results From DAQ analysis more complete check: you test also used TDC (CAEN V 1290), 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 30

Taken data: data taken with 3 bars of different type data taken with different discriminators: L. E. CAEN N 417, L. E. PLS 711, CF ORTEC 8000 data taken with different TDC: CAEN V 1290, CAEN V 775 QADC data (for time-walk corrections) available M. Bonesini - MICE Collaboration Meeting 9/10/06 31

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

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 33

Intrinsic time resolution of TOF bars Run 141 – 149 Distributions of (Tleft – Tright )/2 TDC V 1290 Bicron BC 420 - 4 cm thick impact point at 10 cm from Center Discr CAEN N 417 σ = 63. 91 ps Bicron BC 420 - 4 cm thick impact point at center Discr CAEN N 417 σ = 66. 18 ps Bicron BC 408 - 6 cm thick impact point at center Discr CAEN N 417 σ = 109. 7 ps M. Bonesini - MICE Collaboration Meeting 9/10/06 34

Intrinsic time resolution of TOF bars Run 124 – 133 Distributions of (Tleft – Tright )/2 TDC V 1290 Discr CAEN N 417 Bicron BC 420 - 4 cm thick impact point at 15 cm from center (5 cm from edge) σ = 72. 73 ps Bicron BC 420 - 4 cm thick impact point at center σ = 64. 91 ps Bicron BC 408 - 6 cm thick impact point at center σ = 107. 2 ps M. Bonesini - MICE Collaboration Meeting 9/10/06 35

Intrinsic time resolution of TOF bars Run 215 – 217 Distributions of (Tleft – Tright )/2 TDC V 1290 Bicron BC 420 - 4 cm thick impact at center Discr PLS 711 σ = 44. 22 ps Bicron BC 420 - 4 cm thick impact point at center Discr PLS 711 σ = 97. 16 ps (PROBLEMS IN PMTs EQUALIZATION) Bicron BC 404 - 6 cm thick impact point at center Discr PLS 711 σ = 49. 21 ps M. Bonesini - MICE Collaboration Meeting 9/10/06 36

CAEN V 1290 vs CAEN V 775 • resolution with V 775 TDC seems even better than with MCA analysis (41 ps) • but from CAEN team intrinsic resolution of V 1290 is 35 ps as compared to 28 ps of V 775 (we have to understand the difference) M. Bonesini - MICE Collaboration Meeting 9/10/06 37

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 38

A first hint: time-walk Side plots point to a Cut=0; 135 ps jitter/ time-walk problem of used discriminators needs to check with Cut=. 25 ; 125 ps further testbeam data (with CF discriminator) Cut=. 10; 91 ps requires some lab tests on discriminator M. Bonesini - MICE Collaboration Meeting 9/10/06 39

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

Conclusions we need to finalize TOF 1 size: guess 42 x 42 cm 2 instead of 48 x 48 cm 2 we advocate use of conventional PMTs for TOF 1 + global shielding (G. Gregoire design ? ) BTF analysis in course points to good intrinsic counter resolution, reasonable behaviour of V 1290 TDC, but requires to think about discriminators/time walk corrections schedule $-bound M. Bonesini - MICE Collaboration Meeting 9/10/06 41