[Sbs] [New Logentry] RC Daily Summary - 10/02/23

[ojevons at jlab.org]

Logentry Text:
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New day, new problems.

On the good side of things, we were able to run beam on target all of day and swing shifts, and the significant majority of owl. We ran 40uA until halfway through swing, when MCC offered to ramp the current up to 42uA, which was done. With the target polarization holding steady at 42uA, we bumped up to 45uA at 2:20 am, and stayed there for the rest of owl. 

Unfortunately, today has been hampered by some issues. At the end of owl shift (7:30 am), the oven started to lose temperature, so the lasers were turned off pending an access to check what might be wrong. Since then, we took an hour or so of data (on the advice of a target expert, who said that we wouldn't lose too much polarization in that time), before having to stop collecting for the expected escorted access. It transpires that the problem with the oven might be more involved than we originally thought, so we have put the hall at controlled access for most of the day. This disruption shouldn't be too damaging to our run plan; because of Hall B wanting to restart during today's swing, MCC were going to have the beam down anyway for tests on the 4-pass separator and the injector line. 

In the meantime, accesses have been made to look at the target oven, the hodoscope HV supply, HCAL and the BB GEMs, but we're still waiting on the beam to be restored. Also, the problematic laser PC - the one which kept hibernating - has been handed off to the Computing Center to be looked at. They have said that they should get it back to us before we get back into running, but we're still waiting on that.

Since my last log, we have collected 1.346C of corrected charge on the cell, and the polarization has stayed above 38% (at least, whilst the lasers have been on - https://logbooks.jlab.org/entry/4190921).

We will have the regular RC meeting at 3:30pm in the Counting House conference room to discuss the run plan going forwards. Alternately, people can join remotely via:

https://jlab-org.zoomgov.com/j/1616220064
Meeting ID: 161 622 0064
Passcode: 314159

See you there!



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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/4191123
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