[Hallc_running] [New Logentry] RC daily update

sjjooste at jlab.org sjjooste at jlab.org
Thu Oct 11 13:35:01 EDT 2018

Logentry Text:
Very bad beam quality since yesterday. Overall physics efficiency was below <17%. You can see more details here: https://logbooks.jlab.org/entry/3607707
The last 2.5h shutdown this morning was for machine tuning, and things started to look a bit better for a while. We took a dummy run at 40uA and were able to get ~90% efficiency for 100 minutes! Unfortunately, once we moved back to LH2 things look unstable again, with a very high trip rate. Operations claims they don't know what changed.

This night during owl, the HMS Dipole LN2 fill level alarm went off. We have been talking to Andy Kenyon since, and agreed we can live with this level until we find an opportunity for an escorted access, probably early next week. The only side effect is the formation of a minor ice ball in a non-critical location. More info here: https://logbooks.jlab.org/entry/3607689

We stayed in the (important) Q2=3. W=3.14 x=0.25 theta_Shms=9.42 deg setting for the last 24 hours. We collected an additional 18% of statistics goal on LH2 for a total of 30%. This morning, we also conducted a (very successful) dummy run. We project/hope to reach 50-60% of the statistics goal on LH2 by midnight tonight. We will then proceed to the next SHMS angle of 6.50 degrees. Note that this angle is slightly lower than what is in the printed run-plan for a more optimal kinematic coverage.

There will be an RC meeting today at 4:30 pm on the second floor of the counting house.

To join the Meeting:
To join via Room System:
Video Conferencing System: bjn.vc -or-
Meeting ID : 861439920
To join via phone :
1) Dial:
+1.408.740.7256 (US (San Jose))
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(see all numbers - http://bluejeans.com/numbers)
2) Enter Conference ID : 861439920


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/3607718
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