[Hallc_running] [New Logentry] Staus Update

[pooser at jlab.org]

Logentry Text:
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Since yesterday day shift, the high power tests of the machine have proven to be unbelievably fruitful for F2.  In total, 1 kinematic point for electrons (SHMS: 33 deg -> 1.7 GeV) and 5 kinematic points for positrons (SHMS: 39 deg -> 1.8 & 1.3 GeV, 29 deg -> 2.7 & 2.0 GeV, HMS: 59 deg -> 1.2 GeV) have been completed for LH2, LD2, and 10 cm Al dummy targets (https://logbooks.jlab.org/entry/3547570).

MCC plans to continue with the high power tests until day shift tomorrow with no major downs scheduled.  Currently the RF trip rate is ~4 trips/hr however, the BLM trips are a factor 3 higher and are not understood.  Tomorrow accelerator will formulate a plan to address the underlying issues that have been exposed in the past few days.  Whether or not the fixes will result in us being able to make access to the hall is not able to be determined at the moment although, we will have more information after the 7:45 am meeting tomorrow.

Jack informed us yesterday after his brief access that the issues with the HMS dipole power supply are unclear and estimates that the work will take approximately 1-2 days to repair (https://logbooks.jlab.org/entry/3547029).  On a good note, since his access the power supply has been holding steady and survived a momentum change (https://logbooks.jlab.org/entry/3547559) allowing us to continue with the HMS run plan.  

Moving forward we will continue collecting production data with SHMS at 29 deg and -3.7 GeV and the HMS at 59 deg and +1.05 GeV.  We will likely remain at these configurations until tomorrow day shift.

All shifts are required to be fully staffed unless otherwise notified.

Special Requests:
Brad Sawatzky: DAQ buffer mode tests

Work completed in the hall during accelerator accesses:
Jack Segal: HMS Q2 power supply
Hall-C Techs: HMS dipole penning vacuum gauge

Special notices in effect for shift crews:
Recovering the HMS DAQ: https://hallcweb.jlab.org/wiki/index.php/Hall-C_HMS_DAQ_Failure_Modes
TO Instructions for LH2 <--> LD2 switches : https://logbooks.jlab.org/entry/3534487, https://logbooks.jlab.org/entry/3547019

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This is a plain text email for clients that cannot display HTML.  The full logentry can be found online at https://logbooks.jlab.org/entry/3547624
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