Recent Changes and Current Issues

Recent Changes

• NEW: when starting a new run after a successful end, do not go from Prestart, but Abort, Download, Prestart, and Go.

• Run #18740: Trigger bit 30 https://logbooks.jlab.org/entry/4218054

• 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 50-60 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.

• Target Change in the Hall: In case of questions from MCC about the necessary controlled access, refer to the logbook entry #: 4196113 for the access requirements. We do need escorted access after >=90nA (on the CuSn target).

• New RICH recovery protocol: see the "Shift Expert" tab for the up-to-date information to avoid unnecessary recoveries.

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.

• Currently, the Faraday Cup can not be used for the beam current or accumulated charge measurements as the vacuum is degraded after the ion pump failure.

• Tagger Magnet Procedure: If the tagger magnet needs to be turned off, tell the operator to use only the script for degaussing, NEVER do "by hand"! The latter method might/will trip the circuit breaker for the power supply in the Hall.

• BMT/FMT/SVT:

• If new hot channels appear, call the MVT/SVT/MM expert Yuri Gotra (757-541-7539). These channels need to be addressed by the expert.

• BMT Layer 5 SEC1 is OFF;

- As of 11/12/23: BMT Strips of S2L5 and S3L1 were turned back ON for testing; thus, their distributions are different than the current reference run (18767) plot; see https://logbooks.jlab.org/entry/4219589.

• 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. If any of them get disconnected, the message will appear in the run control itself!

• ECAL/PCAL:

• HV channel SEC3_V_E16 is OFF;

• PCAL HV_SEC3_V_E16 HV instability is reported at https://logbooks.jlab.org/entry/4215851;

• Hot PCAL U strip # 43 is observed in "adcEnergy" S3 spectra; see https://logbooks.jlab.org/entry/4215294.

• ECal S5 L8 PMT occasionally disappears for short periods. This behavior is common for both FADC and TDC; see https://logbooks.jlab.org/entry/4219587.

• FTOF:

• FTOF S2 Paddle 19-left and S4 Paddle 17-left are a known "weak" channel that tends to come and go depending on torus polarity and rates, which can't 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 shift.