[Halld] RC Update

[Alexander Austregesilo]

Dear Colleagues,

On Friday afternoon, the vacuum in coil 4 of the solenoid magnet was 
rapidly degrading [1]. The situation was closely monitored but initially 
no action was taken as these so-called 'burps' happen monthly and often 
recover by themselves. When it was finally decided to help the recovery 
with an auxiliary pump, it was already too late and the solenoid dumped 
at around 9pm [2]. Since then, we see the vacuum improve as expected [3] 
and are planning to start ramping the magnet back up today. The magnetic 
field should be fully recovered by tomorrow evening. Please find the 
links to the relevant e-log entries below.

On the accelerator side, the reconfiguration seems to be progressing 
well. They could be able to deliver beam to Hall C as early as Sunday 
during the day, and may want to finalize the tuning to Hall D (AD00) 
during swing shift. This would require a shift crew in Hall D starting 
from 4pm on Sunday. We already have a candidate for swing (thank you 
Mark D.), and would still highly appreciate any volunteer to be on 
stand-by for the owl shift Sunday 10pm-Monday 4am.

Stay tuned for more information in 24h.

Best regards,

Alex

------------------

[1] https://logbooks.jlab.org/entry/3937701

[2] https://logbooks.jlab.org/entry/3937754

[3] https://logbooks.jlab.org/entry/3937887