[Hallc_running] [New Logentry] RC Update

[bduran at jlab.org]

Logentry Text:
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Around Saturday evening, Hall C started to receive high current beam after the bad FSD card that was causing dump viewer ion chamber trips around 30 uA. We had pretty good beam with about 75% efficiency that allowed us to finish our coincidence elastic (including a few sieve runs) and SHMS delta scan data taking.

While we're ramping up the SHMS to 9.005 GeV yesterday, we found out that the SHMS Q2 would stop before reaching the MOL (SHMS Q2 setting is 3475.9 but it stops ramping at ~3415A) https://logbooks.jlab.org/entry/4049984. Tried to reach out magnet on call and magnet techs about this but nobody picked up the phone. Around the same time, we got an interlock on the SHMS HB that wouldn't reset (https://logbooks.jlab.org/entry/4049991). Called the engineer on call who was able to help with the SHMS HB interlock but the Q2 situation. We set the current to the desired value without "fully" cycling it. This morning I reached out to Steve Lassiter. There will be an Engineer on call meeting at 10 am after which we will know better about a plan to fix the magnet problems. As we're planning to take a good part of the production data at SHMS=9.2 GeV, it's important for this problem to be fixed in a timely manner.

During the early Monday owl shift, we switched from COIN DAQ to the SINGLE ARM DAQ. The plan is to start with some single arm calibration data with defocused and focused Q2 with ELREAL trigger and than 3/4 data to check the PID trigger thresholds. During the HMS rotation for the first setting of the calibration runs (20 degrees), once again we had a drive controller fault which interrupted the rotation. Engineer on call was notified and we took an escorted access for engineer on call to reset it. After the successful reset, we took the SHMS/HMS calibration data with defocused Q2 at the first setting. This was to follow by the nominal Q2 calibration data taking but the beam was interrupted with the RSEP8A magnet issue again, a different one. A similar plan followed to fix the MZA8S03 (last week's problematic magnet) will be followed for the MZAAT03. It's likely that we will be down for a few hours. 

We will have an RC meeting at 11 am today. Here is the link:

https://jlab-org.zoomgov.com/j/1607100885?pwd=ZFBsRTFsYm5Zb0laZ0tyZXNjcEE0QT09






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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/4050330
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