RC meeting and Run Plan, Tuesday Oct. 16

From HallCWiki
Revision as of 13:31, 16 October 2018 by Sjjooste (Talk | contribs)

Jump to: navigation, search

Status

  • 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


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