[b1_ana] Fwd: Yield for HRS in E06-010 expt.

[J. P. Chen]

Dustin,

The magnet current drift is a concern related to the spectrometer
acceptance. They usually are small as long as one pays attention.
The current drift for HRS are typically: <10-4 fro the dipole
and <10-3 for the three quads. The effects on the acceptance
need some study to find out. HMS will be different from HRS, but data
should exist from Hall C experiments. SHMS has not been constructed
yet, so only design specs are available.

There are also concerns on acceptance due to beam position drift. These
can also be studied from existing data. But will take a little bit of 
time to
dig out data. The drifts can be minimized with the feedback system built
for parity experiments (regression). But may need to check how well
do they work with very low current (100 nA) beam.

Cheers.

Jian-ping

On 5/31/2013 5:08 PM, Dustin Keller wrote:
> Hi JP,
> Do you know the scale for the non-stochastic changes in
> yield in detector magnet currents.
>
> You mentioned concern in this as a separate entity from
> detector drift.
>
> dustin
>
> On Fri, 31 May 2013, J. P. Chen wrote:
>
>> Hi, Karl,
>>
>> Here are two plots Kalyan produced from the Hall A transversity data.
>> The first one shows the HRS detector stability (we used HRS to 
>> detector pions).
>> The 2nd one shows the beam charge asymmetries from lumi.
>>
>> From g2p data there is already plots on the BCM stability by comparing
>> two BCMs. I am asking Melissa to choose one longest period and plot it
>> against time (instead of run number). It should be ready shortly.
>>
>> Cheers.
>>
>> Jian-ping
>>
>>
>> -------- Original Message --------
>> Subject:     Yield for HRS in E06-010 expt.
>> Date:     Fri, 31 May 2013 11:48:38 -0400
>> From:     Kalyan Allada <kalyan at jlab.org>
>> To:     J. P. Chen <jpchen at jlab.org>
>>
>>
>>
>> Hi Jian-ping,
>>
>> Please see attached plots. I did not get a BCM asymmetry plot, but I
>> included lumi asymmetry plot from Joe's thesis.
>>
>> Kalyan
>>
>> -- 
>> --------------------------------------
>> Kalyan Allada
>> Jefferson Lab,
>> MS 12H3, Suite #4,
>> Newport News, VA 23606
>> Phone(office): 757-269-5352
>> --------------------------------------
>>
>>
>>
>>
>>