RC Meeting and Run Plan, Friday, February 28th 2020

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RC Meeting Information

RC Daily Meetings are at 4:15 PM, 2nd floor Counting House Meeting Room Bluejeans Connection

Friday 28th Feb. 2020.

General updates

  • Problems with 1L07, 1L17 throughout day shift (trippy beam, made Moller difficult, etc)
  • Lost beam mid-Swing and had extended down through OWL (issues in the NL, same cavities)
  • Hall C target ion chamber tripped with no beam in the machine [1]
  • Moller results from Thursday (85.0%) [2]
  • MCC took a few hours this morning to install an 'Easy Button' software patch, and to chase some of the issues from OWL
    • We took an opportunistic access to take a look at a few items at that time
      • Swap USB-ethernet bridge with our spare -- Done (an attempt to address the coil current readback issues w/ LabView)
      • Looked at NMR and EPR hardware connections/settings (https://logbooks.jlab.org/entry/3793821)
        • Found and corrected an internal vs. external trigger source setting switch with the EPR setup
        • This should help the issue with the transverse NMR readback issues [3]
        • No 'smoking gun' found that could explain the large polarization drop on 2/24 though

Notes for the Future

  • Beam studies to understand what is going on with the machine are planned for Tuesday DAY shift
    • We will try to get in in the morning (RC will talk to PD and RadCon -- may need to open target enclosure)
    • Details being worked out, but it'll be a full 7--8 hour shift
    • EPR and pNMR measurements/work are planned during this downtime
    • There are portions of the Beam Studies program that would involve beam delivery into Hall C (no target), so limited opportunity for Access only
  • Injector spot move has been pushed off for at least another week (2--3 hour down)
    • Not much beam over the last several days...
    • Hope is to push it off to the Hall C down that starts March 13, and then just do a reactivation that would carry us through May 6
      • Not sure how it will work out, but goal will be to minimized downs and maximize integrated current to Hall(s)
  • 1 hour run with target out for measure of the background just from the beryllium windows (Filler for next spin-up)
  • Target coil rotation planned for March 13--20
    • Nominal 1-week downtime in Hall C to rotate target coils, install new cell, and transition to d2n program
    • Status Update for target cell Austin:
      • Wall and window thicknesses done
      • Only 'Reduced set' of density measurements available now, will continue measurements this week (issues with laser at UVa?)
      • It would be best for it to arrive at JLab on March 10 (at the latest) to allow locals to mount cell in oven plate before they get involved with target work in Hall.
    • Lots of preplanning to be completed (RadCon, Techs, S&A, Target group, etc)
    • RW-II training for JP, Arun, Brad (Complete the training documentation and take the RW-II test if you haven't already done so)

Pending Issues

  • Beam energy shifts between ARC1:p and INJ:p impacted beam polarization to B/C? (Started 2/18 through 2/28) [4]
  • 3C20 BPM noise issue https://logbooks.jlab.org/entry/3793274
    • Resolved: BPMs found to be in FFB mode, now back in normal mode (Jay)
  • EPR problems [6]
    • Going forward for EPR, I'd try (1) checking the continuity of the cable leading from the RF amplifier to the EPR coil to see if it's stable, (2) measure the current going through the EPR coil, (3) cleaning the single D2 filter (it was very dirty) and confirming the APD gain is indeed set to maximum, measure the DC light output (currently a measly 3.6 mV), then trying another FM sweep. If that doesn't improve it, then (4) remove the D2 filter, measure the DC light output, perform another FM scan.
  • Persistent BLM & ion chamber trips
    • General activation, weird BLM issues (https://logbooks.jlab.org/entry/3792326), Ad-hoc ion chamber threshold adjustments (https://logbooks.jlab.org/entry/3792095)
    • NOTE: Shift crew should NOT give authorization to MCC change ion chamber thresholds. If they ask, tell Operator to contact an appropriate expert. Make a log entry if trips persist, or call the RC if it becomes severe (for example, >20 trips/hour is getting intolerable)

Opportunistic Access Jobs

Current Run Plan

  • Take production data (HMS/SHMS -3.5/-3.4 GeV) with 3He target, longitudinal polarization with NMR every 5 hrs.
  • At the next NMR time (if beam is OK, that should be Friday around 6pm) do the following:
    • Take longitudinal NMR
    • Rotate target to 90deg
    • Take transverse NMR
    • Take 3 hours of transverse production data (HMS/SHMS -3.5/-3.4 GeV) with 3He target (no change in kinematics)
    • Take transverse NMR
    • If polarization is still high, then
      • Take 3 hours of transverse production data (HMS/SHMS -3.5/-3.4 GeV) with 3He target (no change in kinematics)
    • Else, if polarization is low immediately go back to longitudinal
      • Rotate back to longitudinal (180deg)
    • Take longitudinal NMR
  • Continue taking production data (HMS/SHMS -3.5/-3.4 GeV) with 3He target, longitudinal polarization until further notice. NMR every 5 hrs.

Standing Orders

 If beam goes away for more than 2h, or if during the downtime, MCC does operations
 that may change the beam tuning, then do [https://hallcweb.jlab.or/wiki/index.php/Beam_and_Raster_Checkout_for_A1n/d2n_(Short_Procedure)
 beam recovery procedure] (do YAG viewer part only if you are suspicious of
 the harp scan results)
  • NOTE: Shift crew should NOT give authorization to MCC change ion chamber thresholds. If they ask, tell the Operator to contact an appropriate expert. Make a log entry if trips persist, or call the RC if it becomes severe (for example, >20 trips/hour is getting intolerable)
  • Check the position locks are on.
  • Do your best to accommodate Hall A's request for a PITA scan promptly. It is OK to stop the present runs and start new ones in 5--10 minutes after they are done.
  • Check that CODA is running normally (had one strange hangup lately)
  • Check online replays shortly after starting runs, & full replay results too.
  • Make sure all the beam specs are followed (e.g. no raster size below 4mm on 3He cell).
  • Always take 120Hz of EDTM
  • Fill BTA with realistic numbers. You may follow the guidance coming from "load from EPICS", if it does not overestimate the ABU (as it generally does). https://logbooks.jlab.org/entry/3783171. If we have to lower the beam current we actually want because the beam is too unstable, prorate the ABUs.
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!                                                     !!
!!  ATTN: SHIFT LEADERS                                !!
!!     Please follow the shift summary template on     !!
!!     the laminated SL instructions.                  !!
!!                                                     !!
!!  ATTN: TARGET OPERATORS                             !!
!!  All NMR measurement HCLOG entries should include:  !!
!!     1) A title that clearly lists polarization      !!
!!     2) Screenshots of both NMR_FieldSweep and       !!
!!        the polarization fit                         !!
!!                                                     !!
!!     For an example see the following entry:         !!
!!     https://logbooks.jlab.org/entry/3768696       !!
!!                                                     !!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Notices in Effect for Shift Crew

  • Policy for CANS-related hall status change: Make a logbook entry when the hall goes in, or comes out of laser-controlled access.
  • Magnet policies
    • Spectrometer GUI (go_magnets) should always be visible on Shift Leader computer, hcdesk3
    • HMS Q1 must be ramped down in 50A steps in all cases
    • Do not ramp HMS Q2 to zero, only go to 10A and then switch off power.
    • If any magnet trips, snapshot the associated power supply window and post it to hclog before resetting the interlock.
  • Monitor the beam position on target and call MCC immediately if you see large excursions (1 mm level).
  • Ramp rate lock instructions are here and added to checklist[7]

Bluejeans remote connection information

 To join the Meeting:
 https://bluejeans.com/861439920
 To join via Room System:
 Video Conferencing System: bjn.vc -or-199.48.152.152
 Meeting ID : 861439920
 To join via phone :
 1)  Dial:
   +1.408.740.7256 (US (San Jose))
   +1.888.240.2560 (US Toll Free))
   +1.408.317.9253 (US (Primary, San Jose))
   (see all numbers - http://bluejeans.com/numbers)
 2)  Enter Conference ID : 861439920

Useful Links

Target Polarization Angle Conventions

Be VERY clear here about the convention (beam-right/left/up/downstream) vs 0, 90, 180, 270)
for each run period.  More notes and references to log entries are better.

Polarization Calibration Data

ADD LIST OF CALIBRATION RUNS HERE
AND A TABLE OF RELEVANT CALIBRATION CONSTANTS TO USE FOR WHAT RUNS
Cell Calibration
Type 		SHMS Angle
/degree 		SHMS Momentum
/GeV 		Field Direction
/degree 		Calibration Results Status Oven Temperature
/°C 		Log#
Tommy EPR-NMR 11 7.5 90 5.24 %/mV Done 200 3839939
Tommy EPR-NMR 18 5.6 270 5.04(1) %/mV Done 205 3843301
Tommy EPR-NMR 18 5.6 90 undone 205
Tommy EPR-NMR 11 7.5 270 undone 208
Tommy AFP Loss 14.5 6.4 90 1.25%/Sweep Done 200 3840618, 3840143, 3840618
Tommy EPR Amplifier
on/off NMR Signal 		11 7.5 90 Done 200 3839962
Tommy Temperature Test 18 5.6 90 Done 205 3844089
Tommy AFP Loss 18 5.6 270 Done 205 3845255
Tommy Temperature Test 18 5.6 270 Done 205 3845336
Briana EPR-NMR 18 5.6 180 8.60 Done 205 3834036, 3834243
Briana EPR-NMR 18 5.6 270 5.6 Done 205 3835512, 3835587
Austin EPR-NMR 18 5.6 90 4.88 Done 200 3814717
Austin EPR-NMR 11 7.5 180 7.64 Done 210 3817200
Austin EPR-NMR 11 7.5 0 8.13 Done 210 3818761
Austin EPR-NMR 11 7.5 270 4.56 Done 210 3819882
Austin EPR-NMR 11 7.5 270 4.58 Done 210 3822296
Austin EPR-NMR 11 7.5 90 4.91 Done 210 3824907
Austin EPR-NMR 18 0 90 4.58 Done 210 3815895
Austin EPR-NMR 11 0 180 6.91 Done 210 3816724

Target Polarization Database

d2n Run Period

D2n Target Run List: https://docs.google.com/spreadsheets/d/16TrIUXVA-znVNUyEKy9FHaIlcvq-KXzu97k9nJowuE8/edit#gid=0

  • Junhao Chen is maintaining it

A1n Run Period

https://docs.google.com/spreadsheets/d/e/2PACX-1vSoTyDugD8wt3hKmBGZBxwUJTPHmUgyvGVJvM7N6qeVoNWhEXumCwwkPI7Sw9Asae3N4k9h5L0Y7qmw/pubhtml

  • Mingyu Chen will updating the runlist while Murchhana Roy will do the cross check.

Recent polarization measurements

PolHe3 Polarization Measurements

Misc Links

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