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Weekly JLC Physics Group Meeting
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Place: BLDG 3, KEK
Time: 10:30, 97/04/11
[0] Agenda
0.1) General Notifications
0.2) CDC R&D Status and Plan for FY97
[1] General Notifications
1.1) FY97 Budget (Miyamoto)
FY 97 budget request has been made to Iwata-san.
It is expected to be available by the end of this month.
1.2) Norik san
Norik san has come back and will stay at Tanashi branch
till August. He is going to work on the CDC R&D.
Then he is moving to KEK and continue the chamber work
for additional one year.
[2] CDC Group R&D Status and Plan for FY97 (Yamaguchi)
2-1) Present Status
Analysis of cosmic ray test data is on going.
Some preliminary results include:
a) In the central part of the 4.6m test chamber,
the average spatial resolution is about 70 microns
for both normal and inclined (45 degrees) incidence.
The number is a little bit misleading since the
track distribution is not flat, sampling more in the
small drift region where the resolution is good.
b) The drift length dependence of the spatial resolution
shows a quadratic increase towards the longer drift
region, indicating deteriorating effects other than
diffusion. Natural explanation for this is the pulse
height drop due to electronegative gas such as O2,
but this has to be confirmed.
c) The z dependence is under study. The apparent spatial
resolutions seem worse than those for the central part.
This might be an artifact due to L-R ambiguity and
requires more study.
There were some discussions on the magnitude of the
errors on the spatial resolutions of individual wires
and the method to subtract the track extrapolation or
interpolation errors. These points will be clarified
in the next meeting.
2-2) The goal of this year's R&D
The R&D items include:
a) Cosmic ray tests of the 4.6m chamber aiming at
more detailed investigations of dependence on z, angle,
and flow rate, etc.
b) Test for stereo cells using 2 small test chambers
mimicing central and end parts of the real 4.6m JLC
chamber.
c) Improvement of readout electronics: preamplifiers,
in particular, considering impedance matching and
pulse shaping time.
d) Wire material study to minimize creeping, or if
impossible, search for alternate design for endplates
and support cylinders to stand stronger tension total.
This study necessitates Monte Carlo simulations to
estimate effects on calorimetry.
fujiik@jlcux1.kek.jp