T32 status as of 17-Oct

Replacing anode 5cm x 10cm, 64 PADs  1cm x 74ch Even after replacing, achieved vacuum level is ~1.5x10^{-3} Pa already. Wire type cathode is replaced at the same time. (view from bottom) New anode

Beam is come (from 12-Oct)

Brief history 12-Oct; Acc. Study (daytime) and hadron beam G tuning between 23:00 to 4:00 of 13-Oct. TREK tuned their own beam equipments later We saw the signal from 250L GAr using PMTs, near counters, and Lead glass (degraders) 13-Oct; Acc. Study (daytime) and hadron beam group tuning. (21-22 of Oct.) TREK tunes the beamline from magnets put in upstream. (D2, D3, and Q7, Q8 shown in next page). We found D1s have interference between K1.1 and K1.8 beamlines. We studied 250L TPC noise during the beam time.

K1.1BR beamline D1 (B1 shown in plot) has two magnets for K1.1 and K1.8. Both magnets are interfered each other. Confirmed by meas. (yield and momentum) Thus, tuning of K1.1BR beamline is difficult since K1.8 beamline has various magnet’s current setting at present.

History (2) 14-Oct; from 21:00, K1.1BR beamline had beam. Slits in K1.1BR beamline were studied. Tuned Q1 and Q2, but had effects from D1 severely so we stopped tuning. Tuned Fitch Cherenkov and TOF and so forth. T32; studied profile of the beam after degraders. studied lead glass (as degrader) pulse height. DAQ to merge data between ours and TREK has been studied.

History (3) 15-Oct; from 21:00 we have beam TREK tuned the Fitch Cherenkov and TOF continuously. Pion ring PMTs can distinguish pions very efficiently, but kaon ring PMTs has large contamination of pions. (not sure why) ESS was turned on from 8:00am on 16-Oct. but voltage is just upto 150kV. (ideally 550kV) #kaon is around 100/spill@1kW of J-PARC beam after ESS turning on, while K/pi ratio is still 1.5/1000.  they will retune We study the profile, degraders, DAQ continuously.

Degrader study Could be useful for PID. If we require the going-through lead glass event, pulse height can be different. Rate; ~20K pions/spill ~ 100 K+/ spill (TOF1xBDC) After degrader, we have ~¼ rates compared to TOF1xBDC (very preliminary). 20cm 250L Lead Glass Lead glass (K) Lead glass (pi)

Profile study (after degrader) We use scintillation counters to measure the profile. In current condition, we can measure only two points / run time. (since TREK gas the first priority) It seems that we have ~18cm of 1sigma for horizontal. Investigate the reason why we have such a low efficiency in our Near Counters. Try for vertical soon.

DAQ Change 64ch scheme to 96ch (for latest anode) DAC for event tag is included. (but noise from event tag DAC can be issues.) Merging TREK data and our data was succeeded. Optimizing DAQ rate and degrader configuration and K purity is necessary. Time for analyzing data (semi-online) should be optimized, too. PMTs info. could be included using FADC of TREK

Noise Checked the slow monitor/control line Checked the beam related noise. Checked the input of DAC info. from event tagger.  If we disconnect the unnecessary info. of slow control, and DAC info. noise level is better than KEK lab. (RMS ~ 8-10 counts)

Summary Anode is changed for 1cm strips Beam is continuously delivered. K/pi ratio is not so good since it is the beginning of the tuning. We worked on the noise, DAQ, signal timing, degraders, profile, rate of the beam, and not so bad at present level. Plan Pre-cooling test. DAQ test understand the beam properties. (including TREK info., degraders, profile, timing, ESS and so on) Core data taking time is from 23-Oct.

Enjoy the beam ! PMT1 in 250L PMT2 in 250L