Minutes LCTPC WP meeting #107 on June 17, 2010
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Present:
At DESY: Steve Aplin, Ralf Diener, Takeshi Matsuda, Christophe Rosemann, 
               Jan Timmermans
EVO/phonebridge: David Attie, Michael Lupberger, Keisuke Fujii, Akira Sugiyama,
               Leif Jonsson, Gilles De Lentdecker, Uwe Renz, Ron Settles

Apologies: Paul Colas, Klaus Dehmelt, Dan Peterson

1) No general news items

2) PCMAG/LPTPC status, testbeam schedule:
- vertical position measuring device installed; small problem with 'uncontrolled' movement,
   expected to be solved soon
- repaired target stations for testbeams T21 and T22 have been re-installed during this weeks
  shutdown. Will be tested next week when beam is back. 
- Next Asian beam test: will install module and HV test from 30 Aug onwards; electronics
  mounting and DAQ/software tests from 6 Sept. Start data taking for two weeks from 13 Sept.
  Free beam area on 26 Sept. 
- Saclay will probably take over from 27 Sept.

3) News from groups:
Japan - started on 3D-Maxwell electric field calculation, trying to find solution for distortions
            by metal pins (holding the Gate-Gem), by means of cover frame carrying field shaping 
            strips (see slides by Akira)

Saclay - Michael+David showed slides on the 8-Ingrid board (first 4 slides are as in previous 
            meeting). HV was applied for the first time to the grids, up to -275 V in Ar/iC4H10 95/5
            mixture: some 20 nA current, approx. corresponding to the resistance of surface of 
            100 pixels. Some of these 'current' spots can be seen on the Pixelman images taken.
            At this voltage the gain is below 1000, but some broad tracks were seen, likely due to
            alphas. They are working to get the external shutter functioning for triggering on cosmics.   

4) WP5 discussions:
    Takeshi attached the following slides to agenda web page:
    - FYI (slides by Bo Li on status of multi-module tracking) which will be presented on next 
       week's MarlinTPC meeting
    - slides by Catherine Clerc at the Beijing LCWS meeting: slide 5 shows the cable path 10 cm 
       wide
    - slide with TPC dimensions (after discussions at DESY with Takeshi, Klaus, Peter, Jan): 
       redefines some of the dimensions and material; Outer Field Cage (OFC) service area of
       30 mm (in radius) for HV cable, gas access, laser mirrors etc.; IFC also with 30 mm 
       service area, although no lasers foreseen here; central HV membrane, stretched and held
       by membrane grips of 30x20 mm; 25 mm (in z) insensitive region near endplate; material
       of endplate is roughly estimated to be (8% X0) + 8.4% X0 for PCB (numbers from Dan 
       and Takahiro designs) + ~ 2% X0 for electronics. No estimate yet for (mainly power)
       cables (calorimeter people assume DC-DC conversion starting from 50V). 

5) AOB:
    As announced already by e-mail, there will be a MarlinTPC meeting next week Thursday
    24 June 2010 at 14:30 CET

Next WP meeting #108: July 1st, 2010 14:30 CET

JT