[Hallc_running] [New Logentry] Status Update

[pooser at jlab.org]

Logentry Text:
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MCC spent yesterday morning addressing issues with the vertical RF separator which resulted in beam not being available until ~12:30 pm.  Once MCC set up magnetic extraction for Halls A, B, and C, “production running” resumed.  The accelerator experts spent the afternoon trying to understand the machine’s power limitations through probing the BLM’s.

At the beginning of swing shift accelerator reverted back to the same game plan which was executed over the past weekend.  While Hall-A was making an access to address issues with their raster, we were receiving >60 uA beam on target with some instances of 80 uA (https://logbooks.jlab.org/entry/3548422).  At ~7 pm there was a loss of communication with the RF cavity 2L25-8 which took beam down for ~ 2 hrs.  At ~9 pm beam was restored to the hall and we continued talking data through the remainder of swing and owl on LD2 with the SHMS at 29 degrees and -3.0 GeV while the HMS was at 59 degrees and +1.05 GeV.

During owl shift at ~6 am the aforementioned SHMS kinematic point was completed and the momentum was lowered to -2.4 GeV and data collection continued.  Moving forward, the F2 run plan will continue while MCC attempts to better understand issues with the machine.  At 11 am today, the RF group will make a rapid access to spray vacuum seal on the vertical RF separator which will result in beam being down for ~30 minutes.  Given the short amount of time required for the access, MMC does not wish to support any accesses being accommodated for the halls.  Once this work is complete, we will continue data taking.

Special Requests:
Brad Sawatzky: DAQ buffer mode tests, trigger rate ~ 5 kHz, one run of buffer mode 1, one run of buffer mode 10, similar statistics

Work to be completed in the hall during accelerator accesses:
Jack Segal: HMS Q2 power supply
Hall-C Techs: HMS dipole penning vacuum gauge
Brad Sawatzky: HMS 1190 fatal chip error investigation
Brad Sawatzky: HMS HVAC (https://logbooks.jlab.org/entry/3548678)
Ed Foltz: Picture of labyrinth doors 

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

We will meet today in 200C at 1:30 pm (second floor of the counting house)
Link: https://bluejeans.com/543903672
Connecting directly from a room system?
1) Dial: 199.48.152.152 or bjn.vc
2) Enter Meeting ID: 543 903 672
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2) Enter Meeting ID: 543 903 672
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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/3549070
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