RC Update and Run Plan for Aug 16, 2020

RC Meeting Information

RC Daily Meetings are at 4:15 PM, remote

Wednesday Aug 16 2020.

General updates

• Continued with production during SWING
• Several PVs in Target alarm handler disconnected. Brad was able to fix it remotely Target_Alarm_Handler
• QWP drivers and controllers needed to rebooted as well (likely same cause?). Followed Ethan's procedure: Controls_reboot
• Pumping chamber RTD-1 died (more on that below)
• Nitrogen (~1 hour) and Hydrogen (~3 hours) reference cell runs during OWL
• CHL1 2K trip at 08:30 this morning: CHL1_Trip
• QWP Transverse Right optimization during the CHL down: Transverse_Right

Pending problem(s) / Things to track

• Lost Pumping chamber RTD1 during target homing: https://logbooks.jlab.org/entry/3828350

• Target related studies at 90deg
  • Complete a temperature curve study (~1 hour process; ~4 NMR measurements at different temps)
    • Should plan for a 4--6 hour spin-up after this test (ie. do this before Moller or beam studies)
  • Pulse NMR tests (will impact polarization, so need to plan correctly)

• Schedule a Moller for mid week (Thurs?)
  • Can take remaining ref cell data after Moller during spin-up if needed

• HMS Q1 insulating vacuum excursions are getting worse [1]

Recent polarization measurements

Transverse @ 90 degrees: 41.9% NMR OWL

Analysis Update

SHMS update from Murchhana: SHMS_Update

Current Run Plan

Normal Production running

• Prerequisites

• Make sure operational restrictions are followed.
• Make sure the raster size is correct (4--4.5mm)
• Monitor beam parameters/configuration very often and post an entry like this at the beginning of your shift and when run conditions have changed
• Running on cell targets: raster always ON (4--4.5mm, size will be determined by the scraping checks), orbit locks ON, current ramp rate 1 muA/sec
• Always take 120Hz of EDTM
• Fill the BTA with realistic numbers. If the desired beam current is not delivered prorate your ABUs!
• Change the IHWP at least every 8 hours when running on glass cells. If Hall A hasn't changed in 8 hours, call the RC

• Run plan

• Start with beam check out (short procedure): https://hallcweb.jlab.org/wiki/index.php/Beam_and_Raster_Checkout_for_A1n/d2n_(Short_Procedure)
• Continue taking production data on the polarized Helium-3 target. If not able to reach requested current, pro-rate the ABUs

Notes for tomorrow's 9:00 am meeting

• Beam stability / trip rate? ---- Has been somewhat better the past few days
• Accel Maintenance RF-recovery day. Still nothing planned as of yet...
• Steve Suhring was going to check on the voltage to Hall C when he could (as a follow-up from the Hall A issues) -- might need to wait until Monday, but can ask

Future

• Please sign up for shifts next week (when the link works...) --- https://misportal.jlab.org/mis/physics/shiftSchedule/?experimentRunId=HALLC-POL3HE
• There are several owl shifts starting the end of next week
• We are on the schedule to switch to 1st pass on Monday (Aug 24) and switch back to 5th pass on Thursday (Aug 27).
• Check the SAD calender for schedule updates (MCC white board isn't currently being updated)
• Jay still has no set day for maintenance/beam studies for this upcoming week (or the following week): maybe a short Ray Trace beam studies (~ 1 hour)
• The EPR diode was checked again on 08/15, and still appears fine. Continue periodic checks---- https://logbooks.jlab.org/entry/3827793

When there is a Down

• If Hall will have opening for 1+ hours, let Simona know as there is work to do on the SOLID cerenkov.