1. TC status & remaining tasks
What are done and what are not yet
Lepton Flavor Physics with Most Intense Muon Beam
the University of Tokyo
Yusuke Uchiyama

2. Toward engineering run
Counter production
Mechanical design
Electronics
Calibration
Software & Analysis
Toward engineering run
November 23, 2018
Yusuke UCHIYAMA

3. Schedule presented at BVR
Build downstream TC in this year.
Aim at a Michel run at the end of this year.
Small update will be shown by Matteo.
But, in principle,
ON SCHEDULE.
November 23, 2018
Yusuke UCHIYAMA

4. Counter production Remaining tasks, uncertainties
Most of SiPMs were delivered.
Individual SiPM test underway in PV.
→ Paolo’s talk
PCB design was fixed and final soldering test done.
Soldering on PCB is about to start.
Scintillator production underway.
1st counters’ test in mid. of April.
Mass production & test will take a few months
~10 counters / day
Remaining tasks, uncertainties
Scintillator quality.
Final design of fiber injection.
Final design of light shielding.
November 23, 2018
Yusuke UCHIYAMA

5. Mechanical design Remaining tasks, uncertainties
Principal design of mechanics was defined
→ Matteo’s talk
Support structure is under construction in GE
Installation procedure is almost fixed with the ‘new’ end-cap
TC does not conflict with any other system, and probably installed after the end-cap
Remaining tasks, uncertainties
Optical splitter positioning & the mounting scheme is not yet fixed.
Cabling scheme (both for signal cables & optical fibers) has to be defined.
Without the new end-cap, more delicate installation procedure has to be considered involving the other systems.
November 23, 2018
Yusuke UCHIYAMA

6. 36 optical splitters would be placed inside (or close to) COBRA
At each side (DS or US)
256 signal cables.
No cables around the counters
36 optical splitters would be placed inside (or close to) COBRA
4 long fibers comes from cavern
256 fibers
All same length?
To cave
To WaveDREAM
Just image. Detailed design is not yet ready.
November 23, 2018
Yusuke UCHIYAMA

7. Electronics Remaining tasks, uncertainties
Signal cable, reuse of DC cable, was tested and now connector-exchange is underway.
Back-plane is re-designed for better grounding against noise. -> Matteo’s talk To be tested in the beg. of April.
WaveDREAM front-end was tested and good performance was achieved.
Remaining tasks, uncertainties
The other part of WD, particularly, biasing circuit and synchronization.
Ground loop, noise in COBRA.
Cabling scheme in the detector hut to be discussed.
Current readout dynamic range to be decided,
depending on the ageing test results.
Uncertainty in the temperature & the variation inside COBRA
Affects on the operational voltage.
November 23, 2018
Yusuke UCHIYAMA

8. HV & Current
VBD=24.38 ± 0.1 V / SiPM
Bias voltage on WD has to be adjusted for our counter.
Stefan asked demanded current range to be measured on WD. HV
VBD/SiPM = ± 0.1 V 30℃ ??)
⇒ VBD /PCB = ± 0.6 V
VOV/SiPM = 2.8 – 3.2 V (from BTC31,32, but to be measured)
⇒ VOV/PCB = 16.8 – 19.2 V
Temperature coefficient 26 mV/℃ from AdvanSiD catalog
to be measured
⇒ 0.16 mV/℃ /PCB
Uncertainty on the temperature. ex. ±5℃ → ± 0.8 V
164.3 ± 2.6 V @ 30℃
a provisional number, to be better estimated later.
VBD=145.5 V
November 23, 2018
Yusuke UCHIYAMA

9. HV & Current From the PSI beam-test we observed
At ~150 kHz, current was ~20 μA with old SiPM
However, at the end of the beam-test, the front two BTCs show up to 70 μA at lower rate.
Aging effect, probably due to muon hits.
The ageing test against light on the SiPM has been conducted in PV, showing no effect on current.
The ageing test against neutron irradiation is underway -> Paolo’s talk
For the safe operation, dynamic range up to 200 μA would be necessary. (provisionally)
We do not need so precise current readout precision, but which will be the precision with that range?
What is the demerit with large dynamic range?
November 23, 2018
Yusuke UCHIYAMA

10. Calibration Remaining tasks, uncertainties Michel
Polish the method for more realistic condition (w/ CDC analysis, pileup, etc.)
The calculation w/ Millepede is unstable
better understanding of Millepede, or
write own minimization code (simpler).
Implement in MEGAnalyzer.
Laser
Understand better the system against reproducibility, offset jump etc.
Establish method of fiber injection & fixation, particularly, for the inner counters.
Get permission to use the laser in the area.
Request two additional readout channels
Laser synchronized signal for trigger & time ref.
Photo-diode signal for monitor & time ref.
Request one dedicated trigger.
Michel calibration was studied with MC & beam-test data,
indicating very high precision (O(ps)) achievable.
Laser calibration study was started -> Kohei’s talk
Most of the optical devices have been tested.
Found that good amount of light can be detected on each counter with the proposed distribution system.
November 23, 2018
Yusuke UCHIYAMA

11. Software & Analysis Remaining tasks, uncertainties
Event & detector simulation in GEM4 is ready.
Framework of event mixing & electronics, waveform simulation in Bartender is ready.
Low-level analysis tasks are implemented in Analyzer
WaveformAnalysis->HitRec->Clustering
Real data analysis has been performed in the SPXAnalyzer -> Miki’s talk
treatment of pileup, noise,
Clustering and tracking
Some event-displays are implemented.
Remaining tasks, uncertainties
Sophisticate the geometry in GEM4 for final design (complicated support, adding fibers, components of PCB, etc.)
Study on SiPM & waveform simulation.
Polish the clustering algorithm for exceptional events (pileup, dead ch, etc) and improve the performance.
Establish the tracking code.
GEANE could not be the optimal solution for TC.
Write own tracking (Kalman filter) code?
Implement in Analyzer.
Prepare calibration tasks.
Evaluate the performance through the full chain of the analysis.
November 23, 2018
Yusuke UCHIYAMA

12. Analysis of MC beam-test data in MEGAnalyzer
Secondary particle hits
MC tracks
(e+: light blue, e-: magenta, γ: yellow)
Rec track (orange)
Counter geometry from MC run header
Waveform from optical photon tracking in GEM and synthesized in bartender
November 23, 2018
Yusuke UCHIYAMA

13. Toward 2015 run
We consider carrying out a Michel run in 2015 is very important toward full run in 2016
We can test full TC performance only with e+ in COBRA
We can find & fix potential issues.
Not only for TC, but for whole the experiment, it is an great step.
We need
Beam, spectrometer, target, DAQ and trigger as well as DS-TC.
Original plan with 16 weeks was reduced to at max weeks.
It is impossible to carry out it in < 14 weeks.
Good progress & preparation is necessary for all the systems. (Submit a progress report at the end of Jun.)
Which kind of trigger could be possible?
Multiplicity trigger would be very useful .
November 23, 2018
Yusuke UCHIYAMA