[g13] Couple of basic questions on TESC EPICS etc

[Ken Livingston]

Hi Edwin,
Sorry, I wasn't very clear on this yesterday.
TESC is read every 2 s. If you keep this bank there is the possibility 
to reconstruct the enhancement and work out the position of the coherent 
edge every 2s.
EPICS has the radiatior position and info and pole plane - and also the 
coherent edge energy as worked out online at the time (which may be flaky).

If you want to do event by event polarization you need to look up the 
polarization table based on the coherent edge position at the time. So 
you either need to determine the coherent edge position from TESC, or 
from a lookup table of event_range/edge position for each run. (I'll 
make both of these).

Given the lack of overhead (367 floats every 2s) I advise people to 
retain the TESC BANK - although they will probably be able to get by 
without it.

In the meantime, you need to continue to use the polarizations provided 
by Neil / Daria.

Cheers,
Ken



On 10/26/2010 08:47 PM, emuneva at jlab.org wrote:
> Hi Ken,
>
> sorry for bothering. You must be very busy but I would like to ask you a
> couple of basic questions about the EPIC and TESC banks just to make sure
> I am doing things correctly or at least to realize about mistakes I have
> in my analysis.
>
> To skim g13b data, I am using the DSTmaker rootbeer template.  The initial
> condition I impose is:
>
> if( ((TAGR_NH)&&(SCR_NS)) || (EPIC_NS) ) return 0;
>
> which I got from other rootbeer template.  However, in Today's meeting you
> mentioned, in addition to EPIC, TESC was also important and by doing:
>
> if( ((TAGR_NH)&&(SCR_NS)) || (EPIC_NS) || (TESC_NH) ) return 0;
>
> I get just a little increment (less than 1%) in the final # of events.
>
> (1)  Do either of those skimming conditions make sense?  I want to make
> sure I am not missing any bank (related to polarization) in the condition!
>
>
> (2) Now, my other question is what role plays the TESC bank in the
> analysis.  I am just using EPIC bank to extract coherent edge, radiator,
> and plane and look at the evolution of the coherent edge along the
> different events/runs.   I have no idea if I should look at another stuff
> from EPIC (like IPM's info) or from TESC which might be important for
> linear polarization checks.
>
>
> Thanks a lot for any help you can provide on this,
>
>
>
> Edwin
>
>
>
>
>    


-- 
=======================================================
Ken Livingston

Dept. of Physics&  Astronomy,        Tel: +44 141 330 6428
University of Glasgow,               Fax: +44 141 330 5889
Glasgow G12 8QQ.
Scotland. UK.
=======================================================