m. bonesini - mice cm18 ral 16/06/071 m. bonesini infn milano updates on tof project

M. Bonesini - MICE CM18 RAL 16/06/07

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M. Bonesini INFN MilanoUpdates on TOF project


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Outline

Hot topics TOF0/1 counter construction Installation issues TOF1/2 PMT shielding

TOF software/simulation TOF readout Conclusions


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Hot issue: detector construction

Material procurement: PMTs delivered Scintillator delivered Electronics in delivery

Counter assembly: mount & calibrate detectors with cosmics. Here we have delays (1-1.5 months)

Production of lightguides (70% done) + glueing in external firm (ALPEAT To) not yet finished

Final counter prototyping is fine (PMTs holders, light tightness, wrapping). Still lacking to finalize laser light injection system into counters: tests in progress to use a laser diode instead of a more expensive Nd-Yag laser

Detector plane assembly: X/Y planes in a rigid structure. Define “interface” with supports


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TOF installation issues

Tof station detector structure


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TOF0 support (with CKOV)

Thanks to Ghislain and Wing


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Space take up for the combined Cherenkov & TOF0

Thanks to Wing


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Hall space available to the Ckov & TOF0

Beam line

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Main concern: access to detectors … 25 cm width is a problem

Thanks to Wing


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Problems:

• cabling (HV, signal, calibration fibers …)

• checks with 3-D calculations: TOF PMTs with mu-metal shielding can bare only B// up to ~ 60 G

TOF1 cage


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A small very useful request from EMCAL and TOF2

Here we require a cable by-pass under the new MICE Hall floor for EMCAL+TOF2 and a basement level hole in the wall for cables


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PMTs tests: conventional PMTs tests: conventional PMTs shieldingPMTs shielding

TOF0 PMTs requires no shielding, aside 1 mm -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// ~ 200-300 G, B _|_ ~ 1000 G)


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Problem: R4998 can bare Bperp but not B//

B//< 50 Gauss fine; B_|_ < 100-120 Gauss fine eventually additional

-metal or soft iron


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B field with one 100 mm iron shield (current design)


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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” by building a 400 G lab solenoid

My old transparency at RAL CM16

BUILT: coil with 5 windings for fields up to 700-800 G


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Advocated solutions:

Solution A (“Ghislain cage”): extra shield (50 mm) connected with joints to first shield (100 mm) and local shielding of PMTs (-metal only if 420 mm hole)Solution B: no-extra shield but heavy local shielding of PMTs a la D0 (test magnet delivered now at Bicocca)


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D0 tests (note # 2706)

Problems:

• It will work for R4998 1” PMTs?

• Tests to be done for Gain + timing

See some results later


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R. Bertoni, M. Bonesini

INFN MIB


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• Laser source (Nichia Blue laser diode + up to 1MHz Avtec fast pulser: signals 100 ps- 2 ns)

• field up to 470 G (now: 40A power), to go up to 700-800 G with new power supply (on loan)

• signal comparable to BTF (~ 500-700 mV)

• Use of different shieldings: mu-metal only, additional Fe shielding, …


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R4998 PMTs: Fe box shielding


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PMT tests results: B//


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0 cm

Extending the Fe box beyond the mu-metal shielding makes it much more effective


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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….

G. Gregoire Shield


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B_r

B_z

G. Gregoire scheme givesvery effective shielding for TOF1/2

500 gauss

-- 500 gauss


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A full 3-D calculation (TOSCA) in progess. Useful to check “small” effects, such as working holes …

Remind max B//~ 60 G with mu-metal only


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Laser calibration + electronics

CAEN FADC (V1724) not yet delivered, but work going on on firmware Pavia group may probably take care of the NINO chip “affair” (this solution is preliminary to any serious thinking about SW: to free the CAEN V1724 FADC used now by TOF) some work on laser light injection in progress with MEG (to allow use of a cheaper laser diode, such as Hamamatsu PLP10): this requires to maximize laser injection efficiency Tests to be done soon with alumized bi-prisms


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TOF simulation studies from Yordan

Simulation and Digitization of the TOF sector are completed

Reconstruction for the simulated data is completed

TofHit, TodDigit, TofSlabHit and TofSpacePoint objects with the relevant pointer links between them are present in the

output of the reconstruction The new code is committed in the packages Persist, DetResp, DetModel, Interface and Recon. We are open for ideas for improvement, for example implementation of dependence of time resolution on the position of the hit in the bar, or anything else.

From Y. Kharazdov presentation at PID meeting


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TOF simulationPositions of the hits in the TOF stations taken from the Simulation

TURTLE beam is usedConfiguration for stage 6 50 000 events are simulated


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Comparison of the times from Simulation and Reconstruction

This time difference is obtained by using 100 ps intrinsic time resolution for each PMT.

This means that we expect 100/sqrt(2) ~ 70 ps intrinsic time resolution for each bar and 70/sqrt(2) ~ 50 ps intrinsic time resolution for each station. This fits very well with what we see in the plots.


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Conclusions

TOF0/1 counter construction is progressing; readout scheme worked out; software issues tackled some installation issues to be spotted out laser calibration system to be finalized still some delays arising from INFN situation not fully worked out (NTA approval, funding [up to now we are at 0 E] …)

m. bonesini - mice cm18 ral 16/06/071 m. bonesini infn milano updates on tof project

Documents

bonesini mice cm18 ral

tof pmts

wing slide

tof project slide

ckov tof

tof0 pmts

pmts tests

new mice hall floor