[Rgc_analysis] [EXTERNAL] Re: RGC Beam Charge Asymmetry & Scaler Bank QA

[pilleux at jlab.org]

Hello Greg,

I have been wondering about the issues you show, and I asked Raffaella and
Nathan about it, I don't know if they had time to look into it yet.

As you show, for many runs there are weird HEL::scaler readings in a
number of files. For these files, the clock information gives crazy
numbers, and the accumulated charge is almost 0. Please find attached a
plot for run 16889 where I plot the time between two consecutive readings
(that I compute from the accumulated charge using the beam current). It is
supposed to be close to 33ms. As you show in slide 10, the first 86 files
look fine but the last 214 don't.

A problem I have with that is that the number of readings which are fine
change run by run, and it makes the normalization of yields, to compute
DSA for example, difficult. For now, all the normalizations of my dvcs
asymetries look crazy (even when I try to include the proportion of 'good'
readings in my scaling).

Best regards, Noémie.

> One more word,
>
> The analysis can be expanded upon by not just looking at file-by-file
> scaler bank observables (for example, what was the fcup accumulation for
> file 'n') , but entry-by-entry observables. In that case, we could ask
> "how does the fcup accumulation evolve within the recon file itself?".
> Perhaps this could help us isolate more outliers or anomalies in the data.
> If any one has an idea of what we could investigate, feel free to let me
> know.
>
> Gregory
> ________________________________
> From: Gregory Matousek <gregory.matousek at duke.edu>
> Sent: Tuesday, September 13, 2022 6:31 PM
> To: rgc_analysis at jlab.org <rgc_analysis at jlab.org>
> Cc: Anselm Vossen, Ph.D. <anselm.vossen at duke.edu>
> Subject: [Rgc_analysis] [EXTERNAL] RGC Beam Charge Asymmetry & Scaler Bank
> QA
>
> Hello all,
>
>>From today's RGC meeting, we were talking about putting in more effort
>> into understanding the beam charge asymmetries from the faraday cup
>> charge accumulation. I put together a presentation here which shows some
>> work on just that
>> (https://cc.jlab.org/system/files/users/gmat%40jlab.org/Presentations/Scaler%20Bank%20QA%20for%20Target%20Polarization%20%40%20RGC.pdf<https://urldefense.com/v3/__https://cc.jlab.org/system/files/users/gmat*40jlab.org/Presentations/Scaler*20Bank*20QA*20for*20Target*20Polarization*20*40*20RGC.pdf__;JSUlJSUlJSUl!!OToaGQ!poBSft7q1QE-VjblFkLfXh9HGcjN1frfU9VC6AYrvF5WWO1CO_fCjHLu0CxfWhleR5s-DA8btLudX_LpgJ-8PlunFRdZ-sWwLy3v$>)
>
> In this presentation, I look into the HEL::scaler and RUN::scaler banks
> for Run 16889 and Run 16918 , the former having an apparent 0.6% BCA and
> the latter -0.02% BCA (slide 16 reports +0.02% but this is because FC+ is
> defined by beam/target spins parallel, where in fact it should just be
> helicity = +1, accounting for just HWP status). We can see anomalies in
> the scaler banks for both runs, which needs discussing.
>
> Please feel free to ask any questions!
>
> Gregory
> _______________________________________________
> Rgc_analysis mailing list
> Rgc_analysis at jlab.org
> https://mailman.jlab.org/mailman/listinfo/rgc_analysis
>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: readscaler.png
Type: image/png
Size: 13670 bytes
Desc: not available
URL: <https://mailman.jlab.org/pipermail/rgc_analysis/attachments/20220914/a396d4b8/attachment-0001.png>