RC meeting and Run Plan, Sunday Oct. 14

Status

• Beam quality: noon update and last 3 hours Bottom line:
  • 35uA looked fine until 03:00, beam has been terrible past this point
  • Accelerator cannot deliver over 37uA at this point
  • Even 37uA seems hard, we are more stable now at 35uA
• Progress

Issues: Resolved

• standard.kinematics file not updated for current run
  • Finished reanalyzing runs 5078 and later during swing, estimated #lambda events doubled (in line with expectation)

• Strange NDX-PosHV alarm under SHMS HGC HV
  • Steve masked alarm in the handler
  • Related to a RadCon detector in the SHMS hut and not our problem

Issues: Requiring attention

Ongoing

• SHMS at small angle
  • (Might) need new limits on diffusor ion chamber if we run above >=50uA (Jay Benesh confirmed might be the case), more info here.
    • Added during RC meeting and Run Plan, Thursday Oct. 11
    • Not an issue right now because we are rate-limited to 37uA,
    • Might become issue once accelerator can deliver higher current again
  • Be wary of DC trips!
    • Added during RC meeting and Run Plan, Friday Oct. 12
    • During luminosity scan, SHMS DCs might trip at >=50uA for one of the settings
    • If we can really reach high current --> be ready to disable SHMS DCs when rates get too high (still want HMS data at those currents).

• HMS Dipole LN2 fill level very high (essentially full)
  • Added during RC meeting and Run Plan, Thursday Oct. 11
  • Not urgent, small ice ball forming in non-critical location (we're watching it)
  • Cause: seems like JT-4 is stuck again
  • Will coordinate with Andy Kenyon for opportunistic escorted access
  • Alarm disabled for now, re-enable when fixed. Instructions

Activities during RF Recovery

• Controlled access tentatively at first opportunity after 9:00am
  • Brad: Install NDX detector in SHMS hut (<1hour)
  • Andy: Replace motor for HMS dipole JT-4 (<10min)
  • Anything else pressing?

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

• Run for 5-6 more shifts with Q2=5.5. W=3.02 x=0.40 theta_Shms=6.49
• Currently 2% of statistics
• Prepare for 1-2 shifts of luminosity scan early next week (pending sufficient beam quality...)
  • Maybe at least do lower points even if beam can't go up (just in case)?
  • Tentatively Monday and/or Tuesday SWING when we have experienced shift crew
  • Could maybe use 3rd worker to help with frequent 15min run changes.