[clas_members] RGC status and shifts

Eugene Pasyuk pasyuk at jlab.org
Mon Nov 28 10:42:21 EST 2022

Dear Collaborators,

Here is a status update.
Good news: solenoid magnet itself passed electrical tests and is in a good health, it did not suffer any damages after power supply failure.
Power supply needs to be repaired. This activity is lead by the DC Power group form the Engineering division. Replacement part are being ordered.
In parallel we are waiting for a feedback from Danfysik on why this event happened and how to prevent it in the future. The control software is being modified. We also considering possible hardware changes, particularly disabling automated polarity reversal and doing it manually. This applies for both of our magnets.
If we get all necessary parts in time the power supply could be repaired before CEBAF resumes operation in January after holiday break.
Meanwhile we are preparing to start configuration change to FT-ON early, in parallel with power supply work.
The latest news about schedule. The plan is to resume operation four days early, on January 12th instead of the January 16th. Our configuration change should be completed by then. If the solenoid power supply will be fixed by then, RGC will resume taking data and we will have to staff shifts.
Our shifts schedule has shifts assigned starting from January 14th. If Hall and accelerator are ready by January 12th we may need to find volunteers to cover two days.
Be prepared to cover your scheduled shifts in January.
I'll send further updates depending on the progress with power supply work and configuration change.


From: Eugene Pasyuk
Sent: Friday, November 18, 2022 15:17
To: members, clas <clas_members at jlab.org>
Subject: RGC status and shifts

Dear Collaborators,

As you all know, last Friday we had a major failure of the solenoid. The power supply was badly damaged and needs repairs. We also assessing if the magnet itself is not damaged as a result of this event. The investigation is ongoing. We are also investigating what was the root cause of this incident. All monitoring data were sent to Danfysik, the company which built this power supply. It is important to understand what went wrong in the power supply because we use exactly identical power supply for the torus. We need more time to fully assess all damages and then depending on findings understand how much time will be needed to bring the solenoid back to life.
Meanwhile, it is clear that it will not not happen before the year end. As of now all shifts are canceled until mid January.

We will send an update as soon as we have any new information.

Stay tuned.

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