Meeting 2021 10 27

GMn GEM commissioning Meetings: WEDNESDAY 10:00am - 11:00am

Link to all previous meetings: GMn GEM Commissioning Meeting

Please use sbs_gems mailing list for plots/communications and HALOG entries relevant to GEMs!

GEM Alignmnet - Sean
UV replacement layer is in INFN test lab on nitrogen. HV has been tested. Unclear when we will install (depends on Jessie for support). Resistor replaced photo
Current BB/SBS experiment status: https://logbooks.jlab.org/entry/3932961
Resistor changed out on UV layer 0 https://logbooks.jlab.org/entry/3930452
10uA on deuterium in last SBS kinematics (highest currents/occupancies so far): https://logbooks.jlab.org/entry/3931870
BB GEMs currently back on nitrogen while Hall A work is ongoing https://logbooks.jlab.org/entry/3932943
GEM HV supplies disconnected yesterday for Hall A work https://logbooks.jlab.org/entry/3932945
BB GEM gas switches ok now. Still plan to calibrate the mixing unit in the future with Jack, but probably lower priority than the Hall A issues.
INFN trip limits https://logbooks.jlab.org/entry/3931889
Currents and set voltages in the EPICS archiver as of Monday https://logbooks.jlab.org/entry/3932174. This was always reported as a snapshot in the HALOG with the BB EPICS start of run entries.
Replay plots post to logbook automagically. Example here: https://logbooks.jlab.org/entry/3932008
MPD 23 (INFN J2 bottom APV backplane) misbehaves with beam and crashes CODA after some number of events. Consistent problem since beam. Not a problem with cosmics.
J0 commmon mode drifts sometimes and seems correlated with the LV cable not being held securely (vertically) in connector. Weight of cable over time pulls it down some.
GEM Current Study SBS - [1]

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