RC meeting and Run Plan, Tuesday Oct. 16
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- Beam quality: [1] Bottom line:
- Beam looked great after beam tuning operations up to 55uA
- Ops still committed to get us the remaining 15uA to go to 70uA
- Beam was steady for luminosity scan
- Hopefully things will keep looking good after RF recovery
- Progress
- Finished [| luminosity scan] with flying colors!
Activities during opportunistic controlled access
- Brad and Pavel:
- Installed NDX detector in SHMS hut (<1hour)
- Steve Lassiter and Andy Kenyon:
- (Hopefully) fixed troublesome HMS dipole JT-4 valve.
- Did maintenance work on HMS and SHMS rotation system.
- Traced cause of screeching noise when opening HMS shutter to a bent rod.
- Not a pressing issue but should be fixed eventually before anything else gets damaged.
Issues: Resolved
- 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
Issues: Requiring attention
Ongoing
- Still bringing down HMS Dipole LN2 level to below yellow alarm level
- Maybe increase upper yellow and red alarm levels if we aren't worried about them?
Request (non-urgent)
- Hall D needs opportunistic 1shift of HallC down for beam studies, not pressing right now (needs to be done before end-of-run)
- Told them this might be possible when swapping out aerogel trays for the next experiment.
- Next RC is aware.
Plans - Physics
- Conduct for 1-2 shifts for luminosity scan starting this swing shift
- Tentative run plan
- Ryan agreed to help as third during swing, and Richard will help as third during owl if needed
- Expect another downtime tomorrow during day for RF recovery
- Run 2-3 more shifts with Q2=5.5. W=3.02 x=0.40 theta_Shms=6.49 (real shifts, excluding scheduled downtime)
- Currently collected 23% of statistics + Al data in 3 shifts
- Switch sometime between Tuesday and Wednesday to the next point