[Halld-tracking-hw] Meeting today

[Curtis A. Meyer]

Hi Tim and Slava -

    we connected in at 1:00pm, but when no one came on by 1:15, we 
assumed that the
lab may be closed again today due to weather. We had a few small things 
to reports that
I think I can safely summarize in an email.

*) With regard to the wires connecting the crimp pins to to the HV 
connector. The
      system that Slava built will certainly work. In fact any of the 
conducting rubber
      will work, but we favored the one with the 0.05 hole and the 
thicker wall.

*)  There is a certain risk involved in not holding the conducting 
rubber to the
       coax with heat shrink cable. In some cases, we have pulled the 
wire out of the
       conducting rubber during installation. In the limited number that 
we did, we were
       able to slip the wire back into the conducting rubber and 
complete the connection.
       However, if we were unable to do this, we would likely be unable 
to connect the
       straw tube. This failure scenario would not occur if the heat 
shrink tube holds the
       conducting rubber to the wire. However, it requires increasing 
the size of the hole
       in the Swiss-cheese plate from 0.138 to 0.156.

*) We would like to investigate a somewhat larger o-ring for the seal, 
but are having trouble
      determining the size of the one that is currently in use. Can some 
one send us the size
      of the part?

*)  In looking at the small aluminum screw that compresses the o-ring 
and seals around the
      wire. While the slot in the top works well for initial tightening, 
after we have soldered
      the wire to the connector to the board at the top, it is currently 
difficult to tighten the screws
      if they need to be. This tightening is clearly the first step in 
mitigating gas leaks.
      Our proposal is to remove the slot at the top and put a 1/4" hex 
head on the part. This allows
      us to use standard tools to tighten it at all states of the 
installation.

*)  For soldering the wire to the connector board, we feel that a small 
plated-through hole in
      the pcb board where the HV line solders on would be helpful. This 
would allow us to
      form a small dog-leg at the end of the wire and use the hole to 
provide some strain relief
      during soldering. This would require one hole per solder point.

Curtis, Gary & Naomi

-- 
Prof. Curtis A. Meyer		Department of Physics
Phone:	(412) 268-2745		Carnegie Mellon University
Fax:	(412) 681-0648		Pittsburgh PA 15213-3890
cmeyer at ernest.phys.cmu.edu	http://www.curtismeyer.com/