[Halld-tracking-hw] Source of oxygen contamination found

[Curtis A. Meyer]

That is great news!   Curtis
On 3/23/12 6:56 PM, Lubomir Pentchev wrote:
> I wanted to inform everybody that our last experiment with the
> testing chamber was successful: just coating the O-ring groove in the
> G10 frame with Hysol reduced the oxygen contamination from 1400ppm to
> 300ppm. Taking into account that the incoming gas has 200ppm, the chamber
> now contributes only 100ppm!
>
> The configuration of the testing chamber is, from bottom to top: Lexan
> sheet, plastic spacer ring (with two Buna-N O-rings), empty cathode G10
> frame (with one EPDM O-ring) on which the groove was coated, top Lexan
> sheet.The gas flow is 220scc/min using 40/60 Ar/CO2.
>
> On Monday we will replace the two Buna-N O-rings with the old type EPDM
> ones, to see if there's an effect. In any case we start preparing for the
> chamber refurbishment and will begin with the third package.
>
>    Best regards,
>     Lubomir
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>


-- 
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/