[clas_members] Hall B status and shifts

Eugene Pasyuk pasyuk at jlab.org
Fri Jan 20 16:28:41 EST 2023

Dear Collaborators,

Here is a brief status update with some good news for a change.
You may have heard that this week we encountered a problem with FTCal, one HV cable was disconnected. To fix it we had to disassemble the beamline to move everything upstream to get access to FT. This was done and FTCal is fully operational. Now we need to put everything back together. Some work remains to be done with the solenoid and its power supply before we can operate it at full field. The current plan is to get ready to energize the solenoid to the full field next Friday, January 27, and run some tests over the weekend. If everything goes well next week we should be ready to resume RGC Monday morning, January 30.
All shifts starting from the Day shift (08:00) Monday, January 30th should report to the counting house as scheduled.

Next week the hall is still open and there we will have an opportunity to do the Hall B safety walkthrough. Please contact me if you need this training.



From: Eugene Pasyuk <pasyuk at jlab.org>
Sent: Friday, January 13, 2023 16:02
To: members, clas <clas_members at jlab.org>; Eugene Pasyuk <pasyuk at jlab.org>
Subject: Re: Hall B status and shifts

Dear collaborators,

Here is a brief status update. The configuration change to FT-ON is complete. The detector checkup is ongoing. The solenoid MPS is alive. It was tested with 2400 A with shorted leads.  This would not have happened without the dedicated work of the DC Power group, Magnet group, DSG, Danfysik team, and Hall B technical staff. This was real teamwork. This is very much appreciated. There are a few minor things that remain to be done with MPS. They will be done next week. After that, we would need to do a series of tests with the solenoid. The polarized target also will be cooled down next week as well.
Our original estimate of getting ready for the beam by January 23rd was a bit too optimistic. Now if everything goes well we are looking at January 26-27.
All shifts are canceled until January 25th.    January 26 and up are on standby.

Stay tuned for further updates next week.


From: clas_members <clas_members-bounces at jlab.org> on behalf of Eugene Pasyuk via clas_members <clas_members at jlab.org>
Sent: Tuesday, December 20, 2022 10:43
To: members, clas <clas_members at jlab.org>
Subject: [clas_members] Resumption of RGC and shifts

Dear Collaborators,

First, a brief status update. The configuration change from FT-OUT to FT-ON is ongoing as planned. It is expected to be completed in the first week of January.
As you all know, the RGC run was suspended on November 11 due to the solenoid power supply failure. The root cause of the failure was analyzed and understood:  it was a bug in the power supply firmware. This was confirmed by the vendor, Danfysik. All replacement parts needed for repair have been ordered and have already been received. The magnet group, DC power group, and Hall B engineering are working on repairs. The engineers from Danysik are expected to be at JLab the second week of January. They will bring newly updated firmware. They will review all modifications done to the power supply and will do tests of both power supplies, torus, and solenoid, with new firmware. Once the power supply tests are successful we will proceed with a comprehensive test of the magnets. The test plan is being developed. This will take at least a week.
Under the most optimistic scenario, Hall B may be ready to receive beam on January 23.
With that said, All shifts are canceled until January 23rd. Since there may be a further delay we recommend to those who have shifts assigned for the week of January 23 and require travel consider the possibility to trade their shift with local collaborators. Especially for expert shifts. For the worker shifts, we still have a remote option possible.
I will send updates if anything changes.

Stay tuned and enjoy the holiday break. Hope to see you in the new year in the counting-house.

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