[Halla_running] [New Logentry] RC update and plans for the weekend

[Paul King]

RC update and plans for the weekend <https://logbooks.jlab.org/entry/3925575>

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Lognumber 3925575<https://logbooks.jlab.org/entry/3925575>. Submitted by pking<https://logbooks.jlab.org/user/pking> on Fri, 10/15/2021 - 18:13<https://logbooks.jlab.org/entries?start_date=1634332412&end_date=1634339612&book=HALOG>.

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

Thursday swing and Friday Owl, we completed the running with the sieve inserted on the 4-foil optics target and the LH2 target. This also involved further HV scans of the BigBite GEMs (https://logbooks.jlab.org/entry/3925085).
The sieve was taken out of BigBite this morning (https://logbooks.jlab.org/entry/3925283).

Thursday afternoon, Jack completed the SBS dipole tests (https://logbooks.jlab.org/entry/3924633), the FSD work was done (https://logbooks.jlab.org/entry/3924637, https://logbooks.jlab.org/entry/3924666, https://logbooks.jlab.org/entry/3924669), and we got authorization to operate the magnet. Jack unlocked the power supply and left it in remote control (https://logbooks.jlab.org/entry/3924673). We decided not to carry out the SBS setup procedure overnight, and instead did that during the Day on Friday (https://logbooks.jlab.org/entry/3925354 and https://logbooks.jlab.org/entry/3925455). The SBS dipole is now at the nominal setting of 2100A.

With the SBS dipole on, we found we needed to steer the beam up slightly to be better centered on the 2mm hole target (https://logbooks.jlab.org/entry/3925482).
We are continuing to use a raster setting of Height=0.9, Width=2.0 to get a ~2mm by ~2mm raster pattern as determined on the 2mm hole target.

We have now taken some data with 1uA of beam on the LH2 target with the sieve out, and are beginning to look at the detector rates and occupancies, and to continue to optimize the detector settings.

Over the weekend, we plan to continue to run on the LH2 target and to push the current up as we are able to optimize the trigger and detector settings. We expect to stay below our current administrative limit of 10 uA for the weekend. Later in the weekend we may take data on some of the solid targets, or on the LD2 target.

On Monday, we will be shutting down before the end of owl to allow the hall to go to restricted access by about 0800 to reconfigure BigBite and SBS. While we are doing the reconfiguration, OPS will be setting us up to take 2-pass beam until next Friday. Next Friday we will reconfigure again to receive 4-pass beam.