[Sbs_gems] [EXTERNAL] Fwd: Fwd: GEM HV scan with new resistors

[Sean Jeffas]

Hi All,

Looks like Brad accidentally only sent this message to a few of us. Since
we have so much time I think we can take at least two data points every day
using cosmics. So we will try to do that.

Best,
Sean

---------- Forwarded message ---------
From: Brad Sawatzky <brad at swatter.net>
Date: Fri, Nov 19, 2021 at 8:15 PM
Subject: Re: Fwd: [Sbs_gems] GEM HV scan with new resistors
To: Ezekiel Wertz <ewertz at email.wm.edu>, Brad Sawatzky <brads at jlab.org>
Cc: Thir Gautam <tns.gautam at gmail.com>, Xinzhan Bai <xb4zp at virginia.edu>,
Jeffas, Sean (sj9ry) <sj9ry at virginia.edu>


We will not have any beam until Tuesday swing at the earliest, probably
later.

If this scan can be done with cosmics (slowly...) Then perhaps it may be
worth doing some of this over the weekend?

On November 19, 2021 7:01:03 PM EST, Ezekiel Wertz <ewertz at email.wm.edu>
wrote:
>
> Hi Brad,
>
> I think you are on the GEM mailing list so you probably saw this
> discussion. At the time of the RC meeting this afternoon I thought the
> table of points for the efficiency scan was set in stone. But that seems
> less clear to me now. Anyway I know we will not be going above 3653 (4100
> equiv) V and I suspect we will go down to 3385 (3800 equiv) V via the
> attached email. Thir is currently the GEM on-call and his number is on the
> whiteboard. I know Xinzhan is on some shifts over the weekend. So depending
> on the timing of beam return and this task he might be able to do it as
> well. It's not entirely clear to me if Kondo and Nilanga have come to a
> consensus on the best form of the efficiency scan they would want. But
> maybe the UVa folks have more knowledge that I am unaware of.
>
> Zeke
>
> ---------- Forwarded message ---------
> From: Holly Szumila-Vance <hszumila at jlab.org>
> Date: Fri, Nov 19, 2021 at 4:09 PM
> Subject: [Sbs_gems] GEM HV scan with new resistors
> To: sbs_gems at jlab.org <sbs_gems at jlab.org>
>
>
> Hi Kondo, Nilanga, all,
>
>
>
> I realize the voltage scan doesn’t need good alignment, but right now the
> alignment was showing the new HV layer with about 14% occupancy, which is
> why I brought up the point about making sure alignment will be somewhat
> ready. Andrew says it will be, so we should be able to see in real time if
> we are getting plateaus.
>
>
>
> The HV scan we completed previously consisted of running:
>
> 3385 (3800 equiv)
>
> 3430 (3850 equiv)
>
> 3475 (3900 equiv)
>
> 3519 (3950 equiv)
>
> 3564 (4000 equiv)
>
> 3608 (4050 equiv)
>
> 3653 (4100 equiv)
>
> 3697 (4150 equiv)
>
> 3720 (4175 equiv)
>
>
>
> Can we reduce some of these points? Should we stay below 3653V or some
> other limit? These values correspond to the divider before modification.
>
>
>
> Thanks,
>
> Holly
>
>
> _______________________________________________
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>
-- 
Sent from my Android phone with K-9 Mail. Please excuse my brevity.
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