[Sbs_gems] [EXTERNAL] RE: [New Logentry] Brief Voltage Spike on uva_xygem_2

[Sean Jeffas]

Hi All,

I scrolled through the logbook and found we had sparks causing > 20 uA
jumps three times total in the past week of running. Therefore it seems
like a rare spark to me, and should not cause any issues, and does not need
any action. We chose our current operating voltages at the very beginning
of the plateau so I think it would be a significant change to decrease any
of them by 50 V.

Best,
Sean

On Mon, Dec 6, 2021 at 3:51 PM Gnanvo, Kondo (kg6cq) <kg6cq at virginia.edu>
wrote:

> Hi all,
>
> I think we should be clear on what we are discussing here!
>
>    - What I saw on the logbook looks like a spark from me and I don’t
>    really think it is something to worry about. We expect that with GEMs
>    unless there is a specific pattern with that spike and in that case we
>    should take ab look and try to understand. I would suggest that GEM expert
>    look at the chart and come with a clear conclusion on that
>
>
>
>    - Reducing HV for 50 V because of APV saturation is a discussion that
>    we had yesterday , so I will not repeat the argument here but let’s try not
>    to mix issues and solution we apply to try to address.
>
>
>
> Best regards
>
> Kondo
>
>
>
> *From:* Sbs_gems <sbs_gems-bounces at jlab.org> *On Behalf Of *David Flay
> *Sent:* Monday, December 6, 2021 3:46 PM
> *To:* Liyanage, Nilanga K (nl8n) <nl8n at virginia.edu>; sbs_gems at jlab.org
> *Subject:* Re: [Sbs_gems] [New Logentry] Brief Voltage Spike on
> uva_xygem_2
>
>
>
> Thanks Nilanga,
>
>
>
> Zeke and I will do that before we start the next run.
>
>
>
> Best regards,
>
> David
>
>
>
> ----------------------------------------------------------------
>
> David Flay, Ph. D.
>
> Hall A/C Staff Scientist
>
> Thomas Jefferson National Accelerator Facility
>
> Office: CEBAF Center, C119
>
> ----------------------------------------------------------------
>
>
> ------------------------------
>
> *From:* Liyanage, Nilanga K (nl8n) <nl8n at virginia.edu>
> *Sent:* Monday, December 6, 2021 3:37 PM
> *To:* David Flay <flay at jlab.org>; sbs_gems at jlab.org <sbs_gems at jlab.org>
> *Subject:* [EXTERNAL] Re: [Sbs_gems] [New Logentry] Brief Voltage Spike
> on uva_xygem_2
>
>
>
>
>
> Hmmm, that is a bit worrying.
>
>
>
> I think, until we understand this a bit more, we should back down the HV
> on just this one module by 50 V.
>
>
>
> I expect the reduction of efficiency to be very small because of this
> change. So I think we should do this soon.
>
>
>
> Best
>
>
>
> Nilanga
>
>
> ------------------------------
>
> *From:* Sbs_gems <sbs_gems-bounces at jlab.org> on behalf of flay at jlab.org <
> flay at jlab.org>
> *Sent:* Monday, December 6, 2021 3:20 PM
> *To:* sbs_gems at jlab.org <sbs_gems at jlab.org>
> *Subject:* [Sbs_gems] [New Logentry] Brief Voltage Spike on uva_xygem_2
>
>
> Brief Voltage Spike on uva_xygem_2
> <https://logbooks.jlab.org/entry/3957495>
>
>    - Edit
>    <https://logbooks.jlab.org/entry/3957495/edit?destination=email/send>
>    - Delete
>    <https://logbooks.jlab.org/entry/3957495/delete?destination=email/send>
>
> *Lognumber 3957495 <https://logbooks.jlab.org/entry/3957495>. Submitted by
> flay <https://logbooks.jlab.org/user/flay> on Mon, 12/06/2021 - 15:17
> <https://logbooks.jlab.org/entries?start_date=1638818252&end_date=1638825452&book=HALOG>.
> *
>
> *Logbooks: *
>
> HALOG <https://logbooks.jlab.org/book/halog>
>
> *Entry Makers: *
>
> flay
>
> Just catching up on this after the DAQ has settled back in and the HCAL HV
> was power cycled.
>
> At around 13:50 we had a HV spike on uva_xygem_2, see attached.
>
> _______________________________________________
> Sbs_gems mailing list
> Sbs_gems at jlab.org
> https://mailman.jlab.org/mailman/listinfo/sbs_gems
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mailman.jlab.org/pipermail/sbs_gems/attachments/20211206/49401ce3/attachment-0001.html>