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BaBar Drift Chamber Gas System
Calculation of the gas leak of the drift chamber
(updated 08 Sept 2004, V. Poireau)
Method (pdf) (doc) to calculate the DCH gas leak.
There is a semi-automatic script which allows you to compute the leak
for a particular date. You give the date in input to this script, then
it uses the method described in the above document and gives you
the leak rate as well as a ps and a gif file of the fit.
You need to have these 3 files:
- leak.csh
- leak.inp
- leak.kumac
(You could also find/run them under ~babardch/gasLeak/).
How to use this script: type |leak.csh -h| for details.
You can run it interactively: |leak.csh|.
or with arguments: |leak.csh 20Aug2004 14:25:00 15:25:00|
In any case, don't forget, as instructed, to type |exec leak| in PAW!
Some example of leak tests done previously:
- |leak.csh 20Aug2004 14:25:00 15:25:00|
- |leak.csh 11Aug2004 13:00:00 13:20:00|
- |leak.csh 30Jan2002 16:00:00 17:00:00|
Be careful: there is some issue with daylight saving time and
OdcNtupleMaker! It could be necessary to subtract 1 hour to the local
time (during the summer)!
Some results:
Using this method (which helps for coherence of the results), we
obtain:
- 30 Jan 2002: leak rate at 4 mbar = 0.181 l/min
- 11 Aug 2004 (an anormal leak was observed at this time): leak rate
at 4 mbar = 1.07 l/min
- 20 Aug 2004 (the previous anormal leak was fixed) : leak rate at 4
mbar = 0.158 l/min
Page maintained by Vincent.Poireau@lapp.in2p3.fr.
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