[Sbs_gems] [EXTERNAL] BB GEM Efficiency Results

[Sean Jeffas]

Hi Nilanga,

You are absolutely right, I messed up the table for M5. I will adjust the
voltages as you suggest for M5 and M6

Best,
Sean

On Sat, Oct 15, 2022 at 12:43 AM Liyanage, Nilanga K (nl8n) <
nl8n at virginia.edu> wrote:

> Hi Sean
>
> Thank you for completing this analysis quickly; the results look very nice.
>
> I have a couple of questions:
>
>
>    1. Looks like there is a mismatch between your tables and plot. For
>    example, according to the table, for M5 at 3650 V, the efficiency is 78%,
>    but according to the plot it is 84%
>    2. I would argue that looking at your data, for M5 and M6 the
>    suggested voltage of 3650 V is too low. I would suggest at least 3700 V for
>    these two modules.
>
> Best
>
> Nilanga
> ------------------------------
> *From:* Sbs_gems <sbs_gems-bounces at jlab.org> on behalf of Sean Jeffas <
> sj9ry at virginia.edu>
> *Sent:* Friday, October 14, 2022 11:46 AM
> *To:* Sbs_gems at jlab.org <sbs_gems at jlab.org>
> *Subject:* [Sbs_gems] [EXTERNAL] BB GEM Efficiency Results
>
> Hello All,
>
> We have completed the BB HV efficiency scans. See full results here,
> https://logbooks.jlab.org/entry/4055432. As listed our HV settings will
> be:
>
> UV Layer 0 - 3650 V
> UV Layer 1 - 3600 V
> UV Layer 2 - 3600 V
> UV Layer 3 - 3600 V
> XY Mod 4 - 3600 V
> XY Mod 5 - 3650 V
> XY Mod 6 - 3650 V
> XY Mod 7 - 3600 V
>
> These numbers have been chosen as the beginning of the efficiency plateau.
> They all produce above 86% efficiency Please feel free to respond if you
> look at the graphs and think they should be different. Generally we are
> comfortable with all the GEMs operating up to 3650 V, so we can reasonably
> increase some of them.
>
> Efficiency plateaued a bit earlier than I expected. For example UV layer 2
> was used in GMn and we found it was 84% efficient at 3600 V, meanwhile for
> this run we found it is 92% efficient at the same voltage. I wonder if the
> new CM calculations are causing this improvement. Regardless we will run
> like this for now, and increase the voltage if there are any issues when we
> start taking production data.
>
> Best,
> Sean
>
>
>
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