Minutes LCTPC WP meeting #109 on July 15th, 2010
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Present:
At DESY: Klaus Dehmelt, Takeshi Matsuda, Christoph Rosemann, Jan Timmermans
EVO/phonebridge: David Attie, Stefano Caiazza, Paul Colas, Keisuke Fujii,
                Jochen Kaminski, Gilles De Lentdecker, Uwe Renz, Akira Sugiyama,
                Wenxin Wang 


1) (General) News:
    - there will be a rehearsal of Jochen Kaminski's talk (for ICHEP 2010 in Paris)
      on Tuesday 20 July 10:00 CET. The slides will be uploaded to
      http://ilcagenda.linearcollider.org/conferenceDisplay.py?confId=4710
      where also the EVO coordinates are given (no passwd required)

   - our next PRC review is planned for the DESY PRC meeting on 14-15 October,
      which will be held in DESY-Zeuthen(!). We will need to produce a written
      status report of our activities over the past 2.5 years and give
      a presentation in the open session on October 14th. 
      The written report is expected to be delivered 4 weeks in advance 
      of the meeting, i.e. around mid-September, which actually means not that much 
      time from now on in view of the holiday season. Jan T. will contact 
      coordinators for production of regional status reports, although in the final
      report we should probably try to avoid this regional splitting, and merge them into
      a 'global' report of the LCTPC activities.
    
   - it was reported at the meeting that both Mahdu Dixit and Uwe Renz had received 
     invitations for a talk at the next IEEE meeting in November. We will 
     organise rehearsals and reviewing of the written contributions in due time. 


2) PCMAG/LPTPC status, testbeam schedule:
- a geometrical survey of the lifting stage and the magnet is going on by a DESY survey
   team. After re-insertion of the LP in the magnet they will then also survey the TPC
   when moved to different positions inside the magnet.
- the final test of the motor systems with magnetic field ON will be done from two weeks
   before the next testbeam campaign in September.
- Takeshi mentioned that there are still ~500 PCA16 chips in store at the manufacturer.
   They cost 40$/pc, so total cost would be 20 k$. Keisuke Fujii and Ties Behnke agree
   to buy part of it. Takeshi is waiting for a final confirmation of Luciano Musa how many
   he would want to have. Will then decide next meeting how many to order.  

3) News from groups:
Saclay - Paul Colas reported on the successful data taking in a high-intensity beam at 
             CERN SPS (see slides) up to intensities of 180 kHz (over 5 cm^2) at 150 GeV.
             Also a new, faster multi-module DAQ system was commissioned and a readout
             rate of 40 Hz was obtained.
             The detector was a Micromegas resistive kapton bulk LP module with 3 cm drift
             space and performed normally, also at these high intensities.
             Multiple track images can be seen on the last slide of the .ppt file. 
             
          - the Octopuce module (8 Timepix/Ingrids) reached a somewhat higher operating
            point (-290V on the grid instead of -275V before) without sparks, but a few 
            'hot spots' (current ~8 nA). At this voltage in Ar/iC4H10 95/5 the single electron 
            efficiency is close to 25%. At -300V grid voltage the detector becomes unstable.
            It is not (yet) clear how to fix these weak spots. David proposed to make a long
            run at -290V in Saclay to check for stability and robustness.
            Jan T. commented that he is trying to arrange the production of another set of 8
            Timepix/Ingrids which could then be mounted on a spare Octopuce (daughter)board.
            There is some uncertainty on the availability of the facilities at Twente University 
            because of moving to a new building.


4) WP5 discussions:
    - Klaus Dehmelt attached to the agenda page a new version of the sketch of the ILD TPC
      dimensions. Tests of new field cage samples are being prepared, both for the inner field cage
      (IFC) and the outer field cage (OFC). A -60 kV power supply is available for loan from 
      Nikhef at least for a period of 4-6 weeks from 2nd week of August'10. The present thickness
      of the OFC is specified as 60 mm, which seems large. These upcoming sample tests will
      show whether we can reduce that a bit. Note that the 30 mm "service areas" on the inner
      and outer sides of the TPC are choosen that large also because of the driftfield distortions
      in these areas over some 20 mm; 


5) AOB: 
    - the student of Yulan Li in Beijing is no longer available to do simulation studies on the
    ion disk distortions. Paul will enquire with the Indian group if there is somebody to work on this.
    Any other volunteer(s)?

   - Paul said that somebody at Victoria is working on the laser calibration data since a few weeks.

Next WP meeting #110: July 29, 2010 14:30 CET

JT