[Sbs] RC update and plan

[Paul King]

RC update and plan<https://logbooks.jlab.org/entry/3928367>

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Lognumber 3928367<https://logbooks.jlab.org/entry/3928367>. Submitted by pking<https://logbooks.jlab.org/user/pking> on Tue, 10/19/2021 - 19:21<https://logbooks.jlab.org/entries?start_date=1634682104&end_date=1634689304&book=HALOG>.

Last updated on Tue, 10/19/2021 - 19:22

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

The beam recovery in 2-pass did not go very smoothly, taking all night and most of the day to get to have beam able to be delivered to the hall. The beam tune is quite different, and we expect the raster settings to be changed substantially.

At about 15:30, we started to do the target centering and raster size check (https://logbooks.jlab.org/entry/3928197). We were having trouble finding the hole, and discovered we needed to adjust the FADC DAC offset for the LHRS to avoid clipping the negative side.

At 17:19, the South Linac dropped on what initially appeared to be either a problem with LCW or a power glitch. OPS shut down the NL systems before they could drop too. It turns out that a LCW pipe in the South Access Building failed and was spraying water on an electrical panel (https://logbooks.jlab.org/entry/3928348).

FML has been onsite and there is the expectation that LCW systems will be back up later this shift with beam restoration possible by the end of swing or so.

The plan for tonight remains the 2-pass setup and beginning to take production data on the LD2 target. See https://sbs.jlab.org/wiki/index.php/Run_Plan_for_2-pass_Setup for the plan.
We had been in step 5, target centering/raster calibration, having delayed doing the ion chamber calibration on the optic target by suggestion from Yves. We will need to resume the raster calibration when we get back up.

The accelerator will turn off at 06:30 to begin the radiation surveys of the linacs for the maintenance day.

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