[Sbs_gems] [EXTERNAL] Chance for GEM study at 20 uA?

[Sean Jeffas]

Hi Kondo, Nilanga, and Evaristo,

The MCC is investigating some RF beam issues today, and they said that they
will send 20 uA of beam to hall A while doing their study. The question is,
can we keep the GEMs on to see the current draws at 20 uA? We would try it
on LH2, which has already been tested up to 10 uA. Here are the numbers for
currents at LH2 that we have taken so far:

No beam: https://logbooks.jlab.org/entry/3943588
8 uA on LH2: https://logbooks.jlab.org/entry/3943079
10 uA on LD2: Sadly no screenshots were taken, so I will quote the EPICS
values
UV Layer 0: 812 uA        INFN J0 bot: 116
UV Layer 2: 804 uA        INFN J0 mid: 118
UVa XY 0: 743 uA           INFN J0 top: 112
UVa XY 1: 768 uA           INFN J2 bot: 113
UVa XY 2: 769                INFN J2 mid: 113
UVa XY 3: 771                INFN J2 top: 0 (off)


So if we go up to 20 uA on LH2 I assume we double the excess currents found
here we would certainly pass the trip limits on all modules on the front
tracker. This For example UV layer 0 will go up to probably 870 uA. Would
this be safe? Are you guys ok with this test?

Best,
Sean
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