Minutes of feedthrough meeting of 12 February, 2001.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Present: Pof, GV, AD, MLenc, ML, MGF

*) Milestones

	- The VI for measuring HEC cable cross talk
	  was written.

*) Margret is working on a purchase order for the LV
   warm cables.  Chris's account will be debited for
   this purchase (~K$30).

*) The 64x64 crosstalk matrix was measured for one of
   our production vacuum cables, and also for the two
   interconnecting pigtails alone.  The data has not
   been analyzed yet.

*) The pigtail jumper impedance mismatch was measured
   by comparing cross talk data taken with two 50 ohm
   pigtails connected by a 50 ohm jumper with data
   taken with the same two 50 ohm pigtails connected
   by a 25 ohm jumper.  Doing a channel by channel 
   subtraction of these two sets of cross talk data
   shows no bias (distribution centered at zero) resulting
   from using an impedance mismatched jumper.

*) Mark has made a cover for the prototype feedthrough crate.
   This feedthrough crate should be assessed (everyone's
   input is welcome...) before more are made.

*)  Laurent Serin and Christophe De La Taille consider 1000V 
    HiPot tests on the pigtails to be too risky (BNL *is* 
    doing 1000V HiPot tests on their vacuum cable / pigtail
    cable chain).  We will therefore not subject the pigtails
    to the 1000V HiPot tests.  Bob Evans of FCI has promised
    (again) full details of the HiPot and other tests.  Assuming
    that FCI does 1000V HiPot tests at the factory, we will
    try some tests of our own before running the HiPot tests
    on all cables:
	-) 100 HiPot cycles on one cable, with Xtalk, resistance,
	   and impedance measurements before and after the 100
	   cycles for comparison.
	-) Single HiPot tests on ~10 cables, with Xtalk, resistance,
	   and impedance measurements before and after comparison.

*) Aaron brough up the fact that the pincarriers should be
   better protected during the welding procedure.  The pincarrier
   covers are not fully hermetic, and may allow metal flakes to 
   enter, causing potential ground shorts.  Compressed air should
   also be used to thoroughly remove any flakes.

*) Pof checked with Sylvain Tisserant regarding the issue of
   spare feedthrough channels for the EM EndCap calorimeter
   (we already know there are zero spare channels for the HEC
   EndCap calorimeter).  As far as Sylvain knows, there are zero
   spares available in the feedthroughs and no way to re-route a 
   dead channel.  Looks like we have a zero tolerance level for
   dead feedthrough channels.

*) PB and Pof should aim at a visit to BNL in the near future,
   well ahead of the ATLAS week in June.

Agenda for next week:
^^^^^^^^^^^^^^^^^^^^^
- Milestones
- Report from LARG week
- AOB