[G14_run] G14 work on TOF

[Reinhard Schumacher]

Hello Franz,
	I'm glad to see that you are back on line.  For the non-experts, could 
you briefly explain how the ST timing can affect the SC offsets?  I 
would have supposed that the timing of the SC is to the RF-corrected 
tagger, and that the Start Counter plays little role in the overall 
track timing.  But your comments indicate that this is not the case, so 
could you explain that?

Cheers,
Reinhard


___________________________________________________________________
Reinhard Schumacher         Department of Physics, 5000 Forbes Ave.
Carnegie Mellon University, Pittsburgh, PA 15213, U.S.A.
phone: 412-268-5177         web: www-meg.phys.cmu.edu/~schumach
___________________________________________________________________

On 08/14/2012 02:11 PM, Franz Klein wrote:
>
> Haiyun,
> overall the SC offsets in pass0/v5 look quite large for some run ranges!
> This may be in part due to ST offsets, which differ between protons and
> pions by -0.1 nsec ... likely due to poor timewalk correction for ST?!),
> but also SC calibration (if proton and pion offsets differ a lot, check
> gmean (and timewalk)):
>
> until run 68188 ~0.2 nsec for both proton and pion,
> runs runs 68188-68305 ~0.2 nsec for pion and ~0.33 nsec for proton
> (difference between proton and pion likely due to ST),
> runs 68772-68779 ~0.19 nsec for pion and ~0.32 nsec for proton
> (difference between proton and pion likely due to ST),
> the next runs until 68998 poorly calibrated for ST and SC!
> runs 69002-69044 ~ -0.28 nsec for pion and ~ -0.15 nsec for proton
> (difference between proton and pion likely due to ST),
> runs 69061-69113 ~0.42 nsec for pion and ~0.6 nsec for proton,
> runs 69114-69147 ~0.22 nsec for pion and ~0.39 nsec for proton,
> runs 69155-69369 and 69501-69597 have small absolute offsets but 100
> psec difference between pion and proton (likely due to ST),
> for 69370-69500 ~ -0.33 nsec for pion and -0.2 for proton (difference
> between proton and pion likely due to ST),
> runs 69604-69640 ~0.2 nsec for pion and ~0.37 nsec for proton.
>
> At this stage corrections for SC and ST depend a lot on each other
> except individual paddles and large overall offsets: if you focus on
> these and let Jamie work on ST, we should be in good shape.
>
> Greetings
> Franz
>
> On Mon, 13 Aug 2012, Haiyun Lu wrote:
>
>> Dear Reinhard,
>> I corrected all the runs with different offsets. Almost all runs
>> should show very little offsets now. My corrections are based only on
>> pions. The fact that the offsets are different for pions and the protons
>> is out of my control. It most likely links to some other calibrations or
>> corrections.
>>
>> Cheers,
>> Haiyun
>>
>>
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>
> ===============================================================
> Franz J. Klein, Associate Professor
> CUA, Department of Physics
> Washington, DC 20064
> office: Hannan Hall 206 phone: 202-319-6190
> or: Jefferson Lab,CC F-243 phone: 757-269-6672
> ---------------------------------------------------------------
>