Recent Changes and Current Issues

Recent Changes

• To make a logbook entry of the strip charts, right-click somewhere on a blank area in any one of the charts. Un-click ELOG and select HBLOG and submit. The title of the logbook entry can be changed.

• Controlled Access to the Hall:

• After 60-75 nA beam current, we ask MCC to stop the beam down, wait for the beacon to stop flashing (15-20 minutes), and then do not need an escort to go in.

• After 95 nA beam current or a Moller run, the beacon will not stop flashing anytime soon, so we need escorted access, viz the ARM. In that case, we can keep the beam until the ARM arrives at the Counting House.

• ZOOM:

• To keep the 24-7 ZOOM session running in the Counting House, 1) click on https://jlab-org.zoomgov.com/j/1618614939, included on "Remote Shifts" under the runwiki Shift Worker tab, 2) choose the option to "join from browser" (Chrome is recommended) and ignore all other messages to update the ZOOM APP in the pop-up windows, and 3) enter the passcode from the logbook entry in the runwiki Shift Worker tab.

Current Issues

• Beamline:
  • After the HWP change, check the SLM and FCUP charge asymmetry (Q-Asym on Beamline Overview) as the absolute values should be less than 0.1%. If they are out of range, contact the Beamline Expert.
  • The beam position on BPM 2C21A is not essential during production; the beam orbit lock is on BPM 2H01. We want both, 2C24A and 2H01 to have our nominal beam positions.
  • Tagger Magnet Procedure: If the tagger magnet needs to be turned off, tell the operator to ONLY use the script for degaussing, NEVER do it "by hand"! The latter method might/will trip the circuit breaker for the power supply in the Hall.

• BMT/SVT:
  • If new hot channels appear, call the SVT/MM expert Yuri Gotra (757-541-7539). These channels need to be addressed by the expert.
  • BMT HV trips: no screenshots are necessary, power-cycle the channel HV as fast as possible (the underlying script will take care of ramping it up), note the trip and sector/layer in the shift summary. If the same channel trips frequently, ask the expert on call for guidance.
  • BMT S1L5 strip is OFF

• New MVT LV Reboot Procedure:
  • See https://logbooks.jlab.org/entry/4217011 for detailed information on rebooting the MVT LV when observing a drop in BMT strip occupancies. In brief, it requires a reboot of LV as follows:
  • Turn LV OFF from MVT Overview->Low Voltage->MVT-All. LV status indicators should change from green to black;
  • Wait 20 seconds, then turn LV back from the same menu;
  • In the alarm handler, with a 2-minute alarm delay, there can be alarm NActiveCrates, status also reported on the MVT Overview GUI. This alarm will be cleared 2 min after LV is turned back ON;
  • At this point, mvt1, mvt2, and mvt3 ROCS can be rebooted;
  • Start a run (Cancel → Reset → Configure → Download → Prestart → Go).
  • If the beam is ON, and a reboot process takes more than 5 min, please call the DAQ and/or SVT/MVT/MM expert.

• DAQ:
  • Some ROCs keep printing error messages while functioning properly; please see their list in this logbook entry # 4215299 to avoid unnecessary reboots since the printout in the ROC terminal won't change. The message will appear in the DAQ run control if they get disconnected!
  • NEW STANDARD end and start of the run: End run, Cancel, Reset, Download, Prestart, Go. This will ensure proper compression of the FADCs and therefore a smaller data rate.

• DC:
  • Make sure to log every DC trip in the shift summary. Make sure to list WHERE and why, possibly, the trip occurred.

• ECAL/PCAL:

• FTOF:
  • FTOF S2 Paddle 19-left and S4 Paddle 16-left are known to be "weak" channels that tend to come and go depending on torus polarity and rates. This cannot be fixed during this run period; see https://logbooks.jlab.org/entry/4219555 and https://logbooks.jlab.org/entry/4219876.

• RICH:
  • RICH Sector 1 has three missing tiles; this is known, and no action is required from the shifters.
• In case of RICH alarm do the following:
  • Make a logbook entry with screen shots of the RICH temperature and scaler screens, notify the RICH expert (vpk@jlab.org).
  • If the DAQ did not crash continue data taking.
  • For the next run, "restart DAQ".
  • If you still see dead RICH tiles in the temperature or scaler maps,
    • make another logbook entry with screenshots,
    • do a full RICH recovery after the run.
  • If it did not help call the RICH expert.
  • Remember to "restart DAQ" for the next run.