[Halla_running] [New Logentry] RC update and run plan for 17 October

[pking at jlab.org]

Logentry Text:
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Yesterday we took the bullseye scan data for the BPMs, and commissioned the gas cells for this kinematic setting, including an ion chamber calibration up to 20uA on the reference cell filled with H2.
We took a little data on the He-3 target (run 1993) stepping the beam current up to 20uA, and verified that the IC response is comparable to the reference cell ion chamber calibration; see the comparison in https://logbooks.jlab.org/entry/4060717.
We then switched back to the H2 reference cell, because the He-3 was not sufficiently polarized.

We took about 2hrs of data on H2 with SBS set at 30%, which included the SBS GEM latency scan.

The target group has gotten the He-3 polarization system working better, and we are now polarizing it.  We will continue running on the H2 cell until the He-3 polarization reaches abtou 30% (see discussion in https://logbooks.jlab.org/entry/4060886).

We are currently running on the H2 target at a pressure of 137psi on the gauge with SBS on at 2100A and BB on at 700A.  We have about 3-4 hours of beam-on data in this configuration out of the planned 8 hours.

Run plan for the day shift into the start of swing:
1)  Collect H2 data at SBS 2100A.  Continue at nominal 20uA current for now.  Runs should be about 1 hour long.  Every 1-2 hours, stop to take a target polarization measurement.  Collect about 4-5 more hours.
2)  At a convenient time, we should do a BCM calibration run in both SBS and the parity DAQs.  This could happen around lunch time or so.  Take the target out to do this.  Go up to 60uA if possible.
3)  If we hadn't finished the H2 running as described in item (1), then resume that.
4)  When the He-3 reaches a sufficient polarization, we will switch to running on the He-3 target.  SBS should stay at 2100A.  Initially, start at 20uA current.  We may go to higher currents later.  Runs should be about 1 hour long.
5)  If we have time before He-3 reaches a sufficient polarization, move to the carbon optics target.  SBS should stay at 2100A.  Initially, start at 20uA current.  We may go to higher currents later.  Runs should be about 1 hour long.


Looking forward, I think we will want to have the sieve inserted sometime during the day tomorrow.  There is a planned accelerator down on Wednesday morning, so if we want ~2 shifts with the sieve, it might be good to insert it at the end of Tuesday day and then retract it on Wednesday.  Note that the down on Wednesday will be for an accelerator tour, so we will likely have to wait on getting an access until the tunnel surveys have been completed.
On the white board we are still listed as having the reconfiguration and pass change on Thursday/Friday, but I have told the PD that we are likely going to want to shift those to next Monday/Tuesday.


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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/4061111
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