[Halla_running] RC Update and plan for today

[Paul King]

RC Update and plan for today<https://logbooks.jlab.org/entry/3925947>

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Lognumber 3925947<https://logbooks.jlab.org/entry/3925947>. Submitted by pking<https://logbooks.jlab.org/user/pking> on Sat, 10/16/2021 - 11:12<https://logbooks.jlab.org/entries?start_date=1634393521&end_date=1634400721&book=HALOG>.

Logbooks:       HALOG<https://logbooks.jlab.org/book/halog>

Overnight the beam was mostly down due to an RF separator trip and an issue with a vacuum valve in the north linac. We started getting beam again at about 05:30.

We have been taking data starting with a beam current of 1uA, and stepping it up as we evaluate detector response.

Run 11207: 1uA beam current, BBCal threshold -250mV, PS1==1, PS2==2

Run 11208: 2uA beam current, BBCal threshold -250mV, PS1==1, PS2==2, others off
Run 11212: 2uA beam current, BBCal threshold -250mV, PS1==1, PS2==2, others off
Run 11214: 2uA beam current, BBCal threshold -250mV, PS1==1, PS2==2, others off

Run 11215: 3uA beam current, BBCal threshold -250mV, PS1==1, PS2==2, others off

Run 11216: 3uA beam current, BBCal threshold -262mV, PS1==1, others off

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Plan for today:
Take an hour of beam at 3uA, then increase beam current to 4uA. We can probably keep the BBcal threshold at -262mV at 4uA.

We'll look at the detector efficiencies at 4uA, and take an hour of data at that current.

Then we'll increase to 5uA. We may need to change the BBcal threshold to -275mV at that point. Take an hour of data, then I think we'll stay at that beam current until the system experts have a chance to look at the data.

We will try a short run with the zero suppression turned off at the 5uA beam current.

We may try a run with SBS reduced to 50% current to look at the fringe fields influence on BigBite, but I need to verify the procedure with the crew chief before we do that.

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