[Sbs_gems] [EXTERNAL] RE: SBS GEM Meeting Wednesday at 10:30am

[Gnanvo, Kondo (kg6cq)]

Hi all,
I don’t know if anyone had looked at the high current data taken at the last day last week, but the results on efficiency are quite interesting and at the opposite of our assumption so far specially regarding HV current drop.

https://hallaweb.jlab.org/wiki/images/9/9f/LH2_high_beam_current_data.pdf

The link shows the plots for

  *   Slide 1: LH2 @ 15 uA (production) and @ 20, 25, 30 34.5 uA (GEM studies)
  *   Slide 2: LD2 @ 12 uA (production) and @ 34.5 (GEM studies)

In all cases GEM efficiency increases with beam current specially clear for the 4 modules of the last layer contrary to what we have been assuming so far.

Even for LD2 @ 34.5 almost 3 times the rate of production data at 12 uA, the efficiency are significantly higher for 6 of the 8 chambers.

This is one more clue that when it comes to GEM efficiency, there is more to the story than gain drop in the GEMs and this need to be understood. There are al lot of GEM studies that need to be analyzed beyond GEM current vs. beam current

I don’t know if the GEM current were recorded during these high current runs. I am anticipating that we will discuss these findings tomorrow

Best regards

From: Sbs_gems <sbs_gems-bounces at jlab.org> On Behalf Of Holly Szumila-Vance
Sent: Tuesday, February 15, 2022 1:55 PM
To: Sbs_gems at jlab.org
Subject: [Sbs_gems] SBS GEM Meeting Wednesday at 10:30am


Dear all,



We will have our weekly GEM commissioning meeting tomorrow Wednesday 16, February at 10:30 am with the agenda:



- Sean, Zeke, Anu, Holly: update on the BB GEMs

   -Negative pulses

   -NIM article interest?



- Anu, John & Thir: update the UVa GEM layers for GEn-RP

   -APV inventory



-Zeke: Update on INFN GEM layers for GEn-RP



-DAQ updates



Connection details:

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Agenda: https://hallaweb.jlab.org/wiki/index.php/Meeting_2022_02_16

=============



-Holly

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