Subject: Comments from Calice meeting, 11/4/2002

Dear All,

   Just a few comments arising from yesterday's CALICE general meeting
   at Paris 6/7.  Transparencies will appear on the web early next
   week once Jean-Claude and others return from the St. Malo meeting.

   On the tile HCAL, there were a couple of presentations on light
   yields with scintillating tiles and fibres, one from DESY and one
   from Prague, comparing performance for different fibre
   configurations (straight, circular, sigma, embedded in groove,
   using glue, etc.).  There were significant discrepencies between
   the two sets of results (DESY yields factor 3 lower for curved
   fibres than Prage), the best guess being that the DESY fibres had
   either come from a bad batch, or been damaged during manipulation.
   Mikael Danilov from Prague showed some results indicating that when
   curved, the useful lifespan of some fibres was reduced down to 48
   hours before yields < 10% were obtained.  He also reported worrying
   variation between one batch and another received from the
   manufacturer.  Fibres will be exchanged between the two groups to
   try to understand the differences.  Also, the low yields of the
   DESY results were not reproduced by simulations, unlike the Prague
   data which agree with predictions.  (The Prague simulations are
   more complete, but the relative simplicity of the DESY sim. was not
   thought likely to explain the problems.)

   On the ECAL side, I presented our revised plans as per the proposed
   specification that Paul sent out on Monday.  I presented a list of
   assumptions the UK people had made about how the French side of the
   electronics would look, and listed the number and type of signals
   that we think are required at the interface between French/UK
   hardware.  Immediately after my talk, Julien Fleury from LAL
   presented the status of the ECAL VFE electronics for the physics
   prototype and had their version of the same list, which was almost
   identical.  This made for a very positive discussion and we agreed
   that Julien and Paul/I would get in touch to discuss further
   details.  Thankfully, there was no further change in plan from the
   French groups relative to what we had understood at IC...

   There also seemed to be a genuine interest in having some of the UK
   people involved in the energy flow and simulation work, this came
   up several times during the course of the meeting.

   In the Steering Board meeting during the lunch break, there was a
   strong discussion about "information exchange" within the
   collaboration, brought up by Rolf.  Despite protests from
   Jean-Claude B., Rolf went to some length to emphasise that we
   cannot have further misunderstandings as we did at the IC meeting.
   I made it clear that having to revise our plans so significantly
   has embarrassed us and the delay that this causes in getting a
   funding decision from PPARC.  There is another PRC meeting at DESY
   mid-May, a few days after the PPRP meeting.  Although CALICE is not
   on the agenda, RDH will updated people on any changes in the closed
   session, so we should update him very shortly after the PPRP
   meeting with our progress.

   The one negative aspect seems to be related to the digital HCAL
   readout electronics, where there seems to be no effort, ideas,
   etc. at all.  There was a short discussion following my talk about
   this.  The only point agreed was that it has to be read out to be
   used!

   I'll put my slides on the web now, at:

  http://www.ep.ph.bham.ac.uk/user/watson/calice_spec_11_04_2002.pdf,
  .ppt

    J-C. B. will write and distribute minutes of the Steering Board
    meeting after the St. Malo meeting.

        Cheers,
           Nige