[Halla_running] [New Logentry] RC update and run plan for 18 October - 19 October

[pking at jlab.org]

Logentry Text:
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OPS is working on recovering from the ARC9A power supply.  They will be running with the Ext4Orb lock off, which we think should reduce the position excursions after beam trips (see https://logbooks.jlab.org/entry/4062281).

Shift leaders should watch the "TS1-BBHI" rate when we ramp up, and compare to the rates versus current as shown in https://logbooks.jlab.org/entry/4062308.  Also watch the ion chamber values and compare to https://logbooks.jlab.org/entry/4060717.

=== Run plan for overnight into the morning ===

If beam is down due to tuning for our line or for a long down, move to the "no target" position, and follow this procedure to verify the spot size: https://sbs.jlab.org/wiki/index.php/HOW_TOs#If_beam_has_been_down_due_to_machine_tuning

After doing the spot size check, you will need to restore the raster before putting the He-3 cell back into the beam; ask OPS for the raster to be set with Generator 1 Vertical equal to 1.3409, and Generator 1 Horizontal equal to 1.2068.  The settings are shown in the last figure of https://logbooks.jlab.org/entry/4062516. (Older procedure described in https://sbs.jlab.org/wiki/index.php/HOW_TOs#How_to_ask_MCC_to_set_the_desired_raster_size_of_6_mm).

1) Restore beam on the "no target" position.  Turn off the raster, and check the intrinsic spot with harp swipes with 5uA of tune beam at 1H04A and 1H04B, if the spot is still good, turn the raster back on.  If not, ask OPS to adjust the spot size and recheck, like in the procedure https://sbs.jlab.org/wiki/index.php/HOW_TOs#If_beam_has_been_down_due_to_machine_tuning
1A)  Did you turn the raster back on?
2) Put in the He-3 target then ramp to 30 uA.  Shift leaders should watch the "TS1-BBHI" rate when we ramp up, and compare to the rates versus current as shown in https://logbooks.jlab.org/entry/4062308.  Also watch the ion chamber values and compare to https://logbooks.jlab.org/entry/4060717.
3) He-3 runs, at 45uA of beam current. Use ps1==8, ps3==0, all others -1. Take two runs that should each last for one hour.
4) Move the target to the pickup coil position, and the TO should run an NMR sweep to measure the polarization.
5) Move back to the He-3 cell position, and repeat steps (3), (4), and (5).  Beam will be stopped around 08:00 for the accelerator down.

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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/4062581
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