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[lcdds 113] Minutes of the forth meeting for the IR task force, 8/3

Subject:   [lcdds 113] Minutes of the forth meeting for the IR task force, 8/3
From:   "T.Tauchi" <toshiaki.tauchi@xxxxxx>
Date:   Thu, 04 Aug 2005 15:07:10 +0900

Dear Colleagues;

Can you find a minute of the forth meeting for the IR task force ?
We welcome your comment and suggestion.

The next meeting is 10th August, 1:30pm-3pm, 3gokan 425 and TV conference
with 31100.

Our homepage is http://acfahep.kek.jp/subg/ir/bds/mdi/IR.task.force.htm .

Best wishes,
Toshiaki Tauchi

Minutes of the forth meeting for the IR task force

    •     Date and time: 3rd August, 14:00-15:00
    •     Place: 3-gokan, 425, KEK
    •     TV conference (ID=31100)

 Participants: T.Tauchi, Y.Sugimoto (KEK), Abe, H.Yamamoto (Tohoku univ.),
Matsunaga (Tsukuba univ.)

We discussed on the present status of the task force studies and the
WWS/urgent questions.

1. Baseline design of the beam pipe design

 We discussed on what is the baseline design of IR-region, i.e. beam pipe
and forward calorimeters. Since the accelerator will be operated in the wide
space of five parameter sets (nominal. lowQ, lowP, largeY and high
luminosity), the baseline design should be optimized for the most
challenging set, i.e. the high luminosity one. There must be a long shutdown
before the 1 TeV operation, the design can be optimized at Ecm=500GeV.
 The baseline design geometry can be found here, which is extracted from
Sugimoto's talk at the previous meeting.

2. Pair monitor geometry and installation in Jupiter

 H.Yamamoto pointed out that the pair monitor (3D pixel detector) requires a
space of 5cm length and 10cm outer radius in front of the CH2 mask. The
monitor can be modeled by a silicon disc with 2mm thickness and hole(s) of
beam pipe(s) . As shown in the baseline design, there is a 5cm long space
between J and K. So, there is no problem at present. We asked Miyamto for
installation of the pair monitor in Jupiter.

3. Immediate plans

(1) Beam pipe parameters at B=4 and 5 tesla, and also for the new 1TeV high
luminosity parameter sets which A.Seryi has recently suggested , by
(2) Updates of IR geometries based on the baseline parameters as well as
DID, anti-solenoid fields. by A.Miyamoto
(3) Pair background simulation in VTX, IT and TPC by Jupiter, by A. Sugiyama

4. The urgent questions by WWS

 We discussed on our replies on Q6(L*),Q7(VTX_R),Q8(2&20mr) and
Q10(mini-veto), which are directly related to the detector concept. Our
preferred L* and crossing angle should be longer than 4.5m and less than 2m
rad, respectively. The vertex innermost radius(VTX_R) has been defined for
free from the core of pairs as shown in the baseline design, which depends
on the solenoid field of B=3T and the machine parameter set. These choices
must be verified by the Jupiter full simulation of GLD detector in respect
to the background tolerances.

Also, we discussed on the Z-pole running for the detector calibration. The
conditions such as luminosity, period and frequency will be determined by
the CAL-calibration for large number of channels to be calibrated, while the
TPC and VTX may require the Z-pole running in the same way as the LEP2
experiments. Sugimoto roughly estimated the conditions for the digital CAL-
calibration as follows; The total channel number would be 106 for 100 m2
scintillator in the electromagnetic calorimeter with 1 cm2 readout by the
silicon photo-multipliers. Each readout area must be calibrated by MIP
particles, i.e. muons from the Z-pole whose cross section is about 1.5nb.
Integrated luminosity is estimated to 1fb-1 for 10 days with L=1033/cm2/s,
where 3x106 muons will be produced. Each CAL-area will be hit by 3 muons. If
the CAL need more muons, the luminosity must be significantly greater than
1033/cm2/s . Also, muons in jets may be used as well as cosmic rays.
Apparently, the CAL needs more clever calibration method for reducing the
luminosity at Z-pole. Matsunaga agreed that the CAL group will discuss on
this issue in details.

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