RC meeting and Run Plan, Wednesday Oct. 17

Status

Beam Quality Bottom line:
- Yesterday, accelerator had issues getting a good beam back after RF recovery. They finally settled on 50uA as maximum stable current, and we requested 45uA to limit the SHMS singles rate to below 700kHz in the current setting.
- Today around noon accelerator went down to fix some more Hall B related issues, as well as do some work on the accelerator.

Brad and Pavel:
- Installed NDX detector in SHMS hut (<1hour)
Steve Lassiter and Andy Kenyon:
- (Hopefully) fixed troublesome HMS dipole JT-4 valve (caked on grease).
- Did maintenance work on HMS and SHMS rotation system.
- Traced cause of screeching noise when opening HMS shutter to bent drive screws.
- Not a pressing issue but should be fixed eventually before anything else gets damaged.
Lock Hall back up ASAP to show we are ready for beam.:
- Called MCC at noon

SHMS at small angle
- Almost done running at 6.49 degrees, didn't encounter issues with the diffusor ion chambers
- We understand rates enough to avoid DC trips
  - During Luminosity scan found that DC trips start happening around 800-900kHz singles rate
  - At this point, we are either just below, or just above Itrip values for the DC cathodes.
  - Took some data with slightly higher Itrip value (endorsed by Rolf and Mark) during luminosity scan to better understand SHMS performance near the high-rate limit.
    - Reached rates up to ~1MHz

Still bringing down HMS Dipole LN2 level to below yellow alarm level
- Switched to manual mode because auto-mode was happy to stay at 90+%
- Maybe increase upper yellow and red alarm levels if we aren't worried about them?

Hall B asked if they could remove halfway plate until Monday
- We agreed.
Hall D needs opportunistic 1shift of HallC down for beam studies, not pressing right now (needs to be done before end-of-run)
- Might be possible when swapping out aerogel trays for the next experiment.
Greg Smith: Dave Meekins needs access to work on deuterium target for next experiment
- Called today after I locked Hall back up
- Told him there will be opportunity when swapping out aerogel on Monday

Run 2-3 more shifts with Q2=5.5. W=3.02 x=0.40 theta_Shms=6.49
- Currently collected 26% of statistics + Al data in 3.25 shifts
- Can run up to 45uA in this setting
Wednesday-Friday: Run 5 shifts with Q2=5.5. W=3.02 x=0.40 theta_Shms=9.56
- Collect at least 50% of statistics goal
Friday-Saturday: Run 4-5 shifts with Q2=5.5. W=3.02 x=0.40 theta_Shms=12.56
Match statistics for the theta_Shms=6.49 point
FINALLY: 4-6 shift buffer
- Is this enough buffer?
- Wishlist of settings to revisit?