From: Frank Geurts (geurts_at_rice.edu)
Date: Wed Mar 19 2003 - 10:02:32 EST
Jamie -- the tofr HV is back on, ramping started at 10am EST. Could you
make an entry about that in the e-log book.
thanks,
frank
Frank Geurts wrote:
>
> i copy&pasted the relevant log file entries below. As you can see the
> freon flow dropped very suddenly. The isobutane flow follwed but not
> fast enough causing the ratio to jump up (to 2.58 for isob/freon) and
> only stabilize after 4min. We'll have to check whether or not this slow
> response time of the slaved mode is a feature of this system.
>
> After Leonid "unstuck" the freon valve everything came back to normal.
>
> Considering the time of this interruption (<6min) and the low flow rate,
> I don't think the gas mixture ever got critically altered. A good test
> for our SC system, though!
>
> I am not sure about the sf6/isob ratio: this one jumps up to 1. but is
> physically disconnected which puzzles me somewhat. Might be calibration
> non-linearity near 0 of the freon channel ... not sure.
>
> -frank
>
>
> 2003-03-19 08:30:01 #-- GasFlow: 61.9ccm 3.44ccm 0.15ccm #-- Ratios:
> 1.00 0.04
> 2003-03-19 08:31:01 #-- GasFlow: 61.9ccm 3.44ccm 0.15ccm #-- Ratios:
> 1.00 0.04
> 2003-03-19 08:32:00 #-- GasFlow: 61.9ccm 3.44ccm 0.15ccm #-- Ratios:
> 1.00 0.04
> 2003-03-19 08:33:00 #-- GasFlow: 7.1ccm 0.64ccm 0.15ccm #-- Ratios:
> 1.61 0.39
> 2003-03-19 08:34:01 #-- GasFlow: 2.7ccm 0.39ccm 0.15ccm #-- Ratios:
> 2.58 1.01
> 2003-03-19 08:35:01 #-- GasFlow: 2.7ccm 0.27ccm 0.15ccm #-- Ratios:
> 1.78 1.01
> 2003-03-19 08:36:00 #-- GasFlow: 2.7ccm 0.15ccm 0.15ccm #-- Ratios:
> 0.98 1.01
> 2003-03-19 08:37:01 #-- GasFlow: 2.7ccm 0.15ccm 0.15ccm #-- Ratios:
> 0.98 1.01
> 2003-03-19 08:38:01 #-- GasFlow: 61.9ccm 3.19ccm 0.15ccm #-- Ratios:
> 0.93 0.04
> 2003-03-19 08:39:00 #-- GasFlow: 61.9ccm 3.44ccm 0.15ccm #-- Ratios:
> 1.00 0.04
>
>
>
>
>
> Frank Geurts wrote:
>
>>
>> Just talked to Jamie: we decided to keep the HV off for now.
>> Apparently the ratio isob/freon went up and triggered the SC red
>> alarm. Will look into history shortly.
>>
>> more later
>>
>> -frank
>>
>>
>>
>>
>>
>> James Dunlop wrote:
>>
>>> Followup:
>>> Leonid went out there and adjusted the Freon regulator.
>>> It had gotten stuck and the flow was dropping to zero.
>>> It is now at 1.5 atm, checking for stabilization with time.
>>> Turned off the TOFr HV as indicated on the procedure sheet.
>>> Please call the control room.
>>>
>>> --Jamie
>>>
>>>
>>>> Guys,
>>>> Red alarm on tof gas.
>>>> --Jamie
>>>>
>>>>
>>>> --
>>>> James C Dunlop
>>>> jcdunlop_at_star.physics.yale.edu
>>>> Room 11, Bldg. 902B Ph: (631)344-7781
>>>> Brookhaven National Laboratory Fax: (631)344-7566
>>>> Upton, NY 11973 Mobile: (631)834-7782
>>
>>
>>
>
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