[Tpe] TPE

[Larry Weinstein]

Dear Volker,

I think that is an excellent compromise.  We would like to use the CC to 
calibrate our lepton identification at forward angles.  Two sectors 
would provide enough data without wasting gas.

Sincerely,
Larry

burkert wrote:
> Larry, would it make sense to run with only 2 CC sectors filled?
> Volker
>
> On 10/25/10 4:37 PM, George Jacobs wrote:
>    
>> The answer is yes, but only within limits. We currently have enough
>> gas on hand to fill and then run the system for a limited period of
>> time. The detectors are partly full (mostly). The system last ran in
>> Dec 2009, so they will at the very least need topped off. No way to
>> know the exact fill status until we finish (or give up on) filling..
>> Both CC S4 and S5 pressures have dropped significantly since the
>> system was shut down last Dec. That may or may not be a sign of
>> leakage in itself, but we do know there are leaks.
>>
>> We may or may not run out of gas before the run ends. How long exactly
>> we can operate depends on how much gas the initial system fill
>> required and the current system leak rate. It should be obvious within
>> 30 days of system startup, of  just how long we will be able to run.
>> The initial system fill amount required and a current leakage estimate
>> will allow a more precise estimate of system run time before the C4F10
>> runs out..
>>
>> Current C4F10 Inventory
>> Total C4F10 on hand -->  843 lbs
>> Gas required to fill detectors -->  unknown, but>  zero (from system
>> history, 200 lbs is a good average number)
>> Average Gas Usage from last run after fixing the leak -->  7.7 lbs/day
>>
>> An Optimistic Analysis
>> Assuming it requires 200 lbs to fill the system and the leakage rate
>> has not increased, we can run the system for a maximum of 83 days. In
>> order to have the detectors full, we would need to startup Nov 16th.
>> and run until Dec 23, This period extends for 38 days.The system would
>> be restarted on Jan 3 and then run until empty, on or about the middle
>> of Feb. .
>>
>> A not so Optimistic Analysis (likely a worse case scenario)
>> Assuming it required 350 lbs to fill the system and a slight increase
>> in leakage  to 9 pounds per day -->  leaving 493 lbs for ops or a 54
>> day run time. The gas would then run out by mid Jan.
>>
>> In any case, prior to the gas running out, there would be periods
>> where the gas flow would no longer be continuous between distillation
>> cycles.
>>
>> -George
>>
>> burkert wrote:
>>      
>>> Larry, we are currently assuming that the CC is not filled with gas.
>>> George, do we have enough gas to do this?
>>> Volker
>>>
>>>
>>>
>>>    On 10/25/10 1:19 PM, Larry Weinstein wrote:
>>>        
>>>> Dear Folks,
>>>>
>>>> Will we want to have the cerenkov counter filled with gas for the TPE
>>>> run?  It will not be in the trigger, but we might want it to check our
>>>> lepton ID.
>>>>
>>>>          
>>      
>
>
>    

-- 
				Sincerely,
				Larry

-----------------------------------------------------------
Lawrence Weinstein
University Professor
Physics Department
Old Dominion University
Norfolk, VA 23529
757 683 5803
757 683 3038 (fax)
weinstein at odu.edu
http://www.lions.odu.edu/~lweinste/