[Halld-tracking-hw] Meeting today

[Tim Whitlatch]

Hi Curtis,

I had discussions with Slava this morning and here are the results;

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.

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. 
*The ID is snug around the wires purposely and has proved to seal well*. 
If you wish to try other sizes, tests must be completed to show they 
seal well

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?

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?

Cheers,

       Tim

Curtis A. Meyer wrote:
> On 12/20/10 2:49 PM, whitey at jlab.org wrote:
>> Hi Curtis,
>>
>> Sorry about not showing for the meeting today. I did not put it on the
>> calender and had another meeting. I forgot all about it.
>> Why do you wish to use a bigger oring?
>
> The one that is there feels a little undersized in the hole. We want 
> to investigate
> different sizes.
>
>   curtis
>> I will discuss your comments below with Beni and Slava and get back 
>> with you.
>>
>> Tim
>>
>>> 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/
>>>
>>>
>>> _______________________________________________
>>> Halld-tracking-hw mailing list
>>> Halld-tracking-hw at jlab.org
>>> https://mailman.jlab.org/mailman/listinfo/halld-tracking-hw
>>>
>>
>
>
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