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Thanks Tim -<br>
<br>
with regard to the holes in (4), we felt that they needed to be
fairly close to the<br>
connector, perhaps 1mm away or so.<br>
<br>
curtis<br>
On 12/21/10 11:33 AM, Tim Whitlatch wrote:
<blockquote cite="mid:4D10D6D7.1070003@jlab.org" type="cite">
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Hi Curtis,<br>
<br>
I had discussions with Slava this morning and here are the
results;<br>
<br>
1) we are in agreement with the .05 ID conductive rubber tube and
shrink tube over it. This will open the hole of the swiss cheese
plate
to .156 which we believe is ok. The existing prototype set up that
Slava sent should be used to open up some of the holes under the
aluminum fittings and retested to make sure the seal still works.
We
believe it will.<br>
<br>
2) The rubber orings are 75 durometer flouropolymer (Viton) with
2.6mm
ID and a 1.9mm cross-section (see data Slava sent with the
prototype
set up a few weeks ago). Slava had tried several and these worked
the
best. <b>The ID is snug around the wires purposely and has proved
to
seal well</b>. If you wish to try other sizes, tests must be
completed
to show they seal well<br>
<br>
3) We will change to a hex head on the fittings if you believe
this
will work better. I assume you would make a custom open end
wrench?<br>
<br>
4) The holes in the solder tab is a good idea that has been
kicked
around for a year or so. As long as Fernando has no objections, we
will
do it. Do you want the holes as far away from the connector as
possible?<br>
<br>
Cheers,<br>
<br>
Tim<br>
<br>
Curtis A. Meyer wrote:
<blockquote cite="mid4D0FC2E5.2070809@ernest.phys.cmu.edu"
type="cite">On
12/20/10 2:49 PM, <a moz-do-not-send="true"
class="moz-txt-link-abbreviated" href="mailto:whitey@jlab.org">whitey@jlab.org</a>
wrote: <br>
<blockquote type="cite">Hi Curtis, <br>
<br>
Sorry about not showing for the meeting today. I did not put
it on the <br>
calender and had another meeting. I forgot all about it. <br>
Why do you wish to use a bigger oring? <br>
</blockquote>
<br>
The one that is there feels a little undersized in the hole. We
want to
investigate <br>
different sizes. <br>
<br>
curtis <br>
<blockquote type="cite">I will discuss your comments below with
Beni
and Slava and get back with you. <br>
<br>
Tim <br>
<br>
<blockquote type="cite">Hi Tim and Slava - <br>
<br>
we connected in at 1:00pm, but when no one came on by
1:15, we <br>
assumed that the <br>
lab may be closed again today due to weather. We had a few
small things <br>
to reports that <br>
I think I can safely summarize in an email. <br>
<br>
*) With regard to the wires connecting the crimp pins to to
the HV <br>
connector. The <br>
system that Slava built will certainly work. In fact
any of the <br>
conducting rubber <br>
will work, but we favored the one with the 0.05 hole
and the <br>
thicker wall. <br>
<br>
*) There is a certain risk involved in not holding the
conducting <br>
rubber to the <br>
coax with heat shrink cable. In some cases, we have
pulled the <br>
wire out of the <br>
conducting rubber during installation. In the
limited number
that <br>
we did, we were <br>
able to slip the wire back into the conducting
rubber and <br>
complete the connection. <br>
However, if we were unable to do this, we would
likely be
unable <br>
to connect the <br>
straw tube. This failure scenario would not occur if
the heat <br>
shrink tube holds the <br>
conducting rubber to the wire. However, it requires
increasing <br>
the size of the hole <br>
in the Swiss-cheese plate from 0.138 to 0.156. <br>
<br>
*) We would like to investigate a somewhat larger o-ring for
the seal, <br>
but are having trouble <br>
determining the size of the one that is currently in
use. Can
some <br>
one send us the size <br>
of the part? <br>
<br>
*) In looking at the small aluminum screw that compresses
the o-ring <br>
and seals around the <br>
wire. While the slot in the top works well for
initial
tightening, <br>
after we have soldered <br>
the wire to the connector to the board at the top, it
is
currently <br>
difficult to tighten the screws <br>
if they need to be. This tightening is clearly the
first step in <br>
mitigating gas leaks. <br>
Our proposal is to remove the slot at the top and put
a 1/4" hex <br>
head on the part. This allows <br>
us to use standard tools to tighten it at all states
of the <br>
installation. <br>
<br>
*) For soldering the wire to the connector board, we feel
that a small <br>
plated-through hole in <br>
the pcb board where the HV line solders on would be
helpful.
This <br>
would allow us to <br>
form a small dog-leg at the end of the wire and use
the hole to <br>
provide some strain relief <br>
during soldering. This would require one hole per
solder point. <br>
<br>
Curtis, Gary& Naomi <br>
<br>
-- <br>
Prof. Curtis A. Meyer Department of Physics <br>
Phone: (412) 268-2745 Carnegie Mellon University <br>
Fax: (412) 681-0648 Pittsburgh PA 15213-3890 <br>
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href="mailto:cmeyer@ernest.phys.cmu.edu">cmeyer@ernest.phys.cmu.edu</a>
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<br>
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</blockquote>
<br>
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<br>
<pre class="moz-signature" cols="72">--
Prof. Curtis A. Meyer Department of Physics
Phone: (412) 268-2745 Carnegie Mellon University
Fax: (412) 681-0648 Pittsburgh PA 15213-3890
<a class="moz-txt-link-abbreviated" href="mailto:cmeyer@ernest.phys.cmu.edu">cmeyer@ernest.phys.cmu.edu</a> <a class="moz-txt-link-freetext" href="http://www.curtismeyer.com/">http://www.curtismeyer.com/</a>
</pre>
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