[Halla_running] [New Logentry] RC Update (10/21/2022)

[mnycz at jlab.org]

Logentry Text:
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After the RC meeting yesterday, we dropped to controlled access and the polarized target group began working to better understand the source of the low target polarization. They were able to have their RF amplified surveyed and moved upstairs which allowed them to preform EPR calibrations with the SBS and BB magnets on. The main take away from their work yesterday (early this morning) is that it appears that the polarization is actually closer to 30% (as opposed to ~10%)! Below is a link to a nice summary from Gordon detailing their work and current understanding of the system. 
https://logbooks.jlab.org/entry/4064670
I wanted to thank the polarized target group for their hard work the past several days!

After the target work was finished, OWL shift proceeded with a beam line and raster checkout 
https://logbooks.jlab.org/entry/4064685
https://logbooks.jlab.org/entry/4064687
https://logbooks.jlab.org/entry/4064690
and then continued with production on the polarized helium-3 target. 
The plan for today and this weekend is continued polarized helium-3 production data

Yesterday Hall C performed a high current BCM calibration. To accommodate, we were restricted to 35 uA during OWL shift. As of day shift, our operational limit has been restored to 60 uA, with a limit of 45 uA on the polarized / reference cell targets. But there has been some beam instability during OWL and we could only received stable 25 uA beam during OWL and the beginning of DAY shift. 
https://logbooks.jlab.org/entry/4064861
Looking forward, at the 7:45 am meeting, I brought up the desire to shift the reconfiguration / pass change (to 3rd pass) by one week to Monday Oct. 31 (previously it was scheduled for this Monday October 24). They were happy to accommodate this request.  If needed, we can discuss this further today during the 3 pm RC meeting. 
One final note, we have SL shifts open on Sunday OWL and Sunday SWING. And beyond this weekend, the OWL shifts from Monday (10.24) until Friday (10/28) need to be filled. 

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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/4065084
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