[Hallc_running] Run status; shift crew needed!

jmatter at jlab.org jmatter at jlab.org
Fri Jan 24 11:34:35 EST 2020

Hello all spin asymmetry enthusiasts!

We still have several open TO and SL shifts this weekend and during the
next week. Please sign up for as many as you like, and please encourage
anyone you can think of to sign up as well. I'd be happy to bribe you with
donuts, pizza, or any snack you desire (within reason)!

The past 24 hours have been a bit rocky. We didn't take data Thursday
morning due to the DOE tour. Starting in the afternoon, we had several
hours of magnet trouble due to cryo problems that also affected Hall A. We
were able to get everything back up and running by 8PM, but the same arc
dipole power supply that failed early yesterday morning brought beam back
down around midnight.

The target's longitudinal polarization has tended to be in the mid 30%
range. However, we've been able to achieve pretty high polarization lately
(<60%) by leaving the target in the transverse polarization. To take
advantage of this, we rotated to longitudinal polarization at 9:30AM and
will be taking data once MCC gets us beam.

We can discuss the weekend's plans regarding time for longitudinal vs
transverse polarization during the RC meeting today.

We plan to take a Moller measurement on Monday. I'll do my best to
convince Hall B to agree to a spin dance at that time.

- John

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