Run Coordinator report: winter 2023 w2
Wednesday January 24
Past 24 hours
- Beam study, with Hall D access. Then, production on diamond. ABU= 12.2 h for the day.
Shift Reports
Reports
- During Access, a certain number of problems were fixed:
- The TAGH HV crate power was cycled (A. Somov) (See original problem here)
- Target remote control was fixed (C. Carlin)
- Misbehaving pressure sensor was taken care of(Scot). [It looks fine now (Beni)] and [agrees with Newportnews weather station (Naomi)]. Spare sensor was ordered. Should we restore the sensor in the alarm and the usual instruction to stop run if the alarm goes off?
- NMR probe fixed (Tim/Scot). Then it froze again until this morning, 6:24am. Now it is working again after Scot cycled it. Linked to Tagger magnet DCCT current sensor cycling.
- Malte and Mark Dalton worked on FCal.
- Justin worked on DIRC LED issue.
- Scot had Vlad's chiller taken out of the Hall.
- Diamond orientations are consistent with 2020 (Alexander Austregesilo)
- Energy monitoring for Winter 2023 GlueX-II run
Issues
- Start counter 96 degree rotation in cabling or software space (Simon)
- DIRC LED TDC missing (David Lawrence, Justin
- TOF timing (Beni). Later fixed by Sean.
- Long DAQ problem:~1.5h (Alison Laduke/Sergei Furletov). See also Early Riser shift summary
- BCM calibration. Accelerator instrumentation group informed us that last BLA calibration was done in 2021 (beside that done last Thursday, 01/19/2023? To be confirmed) and recommend Ops to do one at each start of the run period.
- A request for the kitchen lights to be fixed should be submitted next time there is beam downtime.
Plans
- Production (300 nA, 2h runs) with cycle:
- 2 runs para(0/90)
- 2 runs perp(0/90)
- 2 runs para(45/135)
- 2 runs perp(45/135)
- 1 run amo (use it to rejuvenate amo reference in CBREM GUI)
- Trigger fine tuning Thursday? (A. Somov)
Tuesday January 24
Past 24 hours
- Production on diamond. Trippy beam, but good availability. ABU=16.2h for the day
Shift Reports
Reports
- Beam profile from Harp scan done Monday morning looks good
- Coherent peak enhancement fit for 2023 (Justin)
- Start Counter performance (Beni)
- Rates comparison for GlueX, PrimEx and CPP/NPP (Alexandre D.)
- Start Counter detector walk (Beni)
Issues
- Tagger Hodoscope HV communication problem (Jon Zarling)
- Main trigger scaler freeze goes unnoticed: Sunday, Monday Can we include them in the scaler summary gui, so it is easy for the shift people to see them?
- NMR probe not communicating.. It started around 4pm Monday. DCCT current monitor for the tagger is also down.(See also Early Riser shift summary)
Plans
- 4h of beam studies + 2h beam restoration). Tagger and Hall to be surveyed around 9pm:
- Safety Walkthrough (M. Dalton + trainee(s))?
- Scot to access to take out Vlad's chiller
- Tagger access for HV communication issue?
- Investigate the faulty pressure sensor?
- Chris Carlin to fix the target controls
- Production (300 nA, 2h runs) with cycle:
- 2 runs para(0/90)
- 2 runs perp(0/90)
- 2 runs para(45/135)
- 2 runs perp(45/135)
- 1 run amo
Monday January 23
Past 72 hours
- Beam was off from Friday 7:30am to Saturday 2am due to vacuum issue in south linac. Friday ABU: 4.0h
- Saturday: Ran on amorphous (goni), 300 nA. Until Sunday 9am when Hovanes started diamond alignment. Saturday ABU: 18.6h
- Sunday 9am-5:30pm: diamond alignment. Sunday 8:30pm - Monday 7:30am: First production 0/90/45/135/amo cycle (see CBrem peak). Then did Harp scans. Sunday ABU: 14.3h
Shift Reports
- Day shift summary Friday, Saturday, Sunday
- Swing shift summary Friday, Saturday, Sunday
- Owl shift summary Saturday, Sunday, Monday
- Early Riser shift summary Saturday, Sunday, Monday
Reports
- Diamond alignment (Hovanes). See also here and here and here
- Empty target vertex reconstruction (Simon Taylor)
- TAGM check and also here (Richard Jones)
- DIRC LED performance (Bill)
- FCAL occupancy plots (Churaman)
- Harp scan Saturday morning. Convergence does not look very good, but we decided to run this way for now (amorphous runs).
- cdc currents (Beni)
- TOF timing resolution (Beni)
- tagger field after power glicth (Alexandre Deur)
Issues
- Numerous pressure alarms. Sensor problem? Since Saturday morning, instruction from Lubomir are that we should only acknowledge the alarms. No need for stoping the ongoing run. See also here. The suspicious sensor has been removed from the alarm (Hovanes)
- Beam energy oscillation investigation: Several accelerator experts are looking at it. No consensus whether it is real or not. Since it is at the MeV level, it should not be an issue for GlueX (but it is for accelerator).
- 30% increase in rates compared to Summer 2020 run period.
- Yields after BCM recalibration (A. Deur)
- Edy (Hall D Accelerator contact) has been asked to follow up on the issue.
- Target control issue.
- Target communication lost around 1pm Friday. Alarm acknowledged by shift crew without action or calling expert. New shift noticed this and called Hovanes. Hovanes informed Alexandre who checked what was the issue and call then Chris Carlin. Chris C. could not come (catching a flight at the airport) but instructed the crew to switch the the back-up IOC, which apparently fixed the issue. However, the controlled came back in a confused state (Full but with heater on, an incompatible situation) so Alexandre informed Chris Keith who went in (beam was off for repair during the whole event) with the shift leader (Dene) and partly fixed the issue by switching the target to local control.
- We can monitor the target, but not control it remotely (switch empty <=> full). For the moment, this is not a crucial problem.
- Numerous DIRC alarms Saturday, see this entry, this one, and the comments in the day and swing shift summaries.
Plans
- Production on amorphous (Goni, 300 nA) until the diamond is aligned.
- Diamond alignment: Sunday morning, ~9am. (Hovanes)
- Then production on diamond radiator, 4 orientations + amo. 300 nA. Presently, we do each orientation once (not twice) and each run is nominally 2h, including the amo run.
- Tomorrow (Tuesday, 24th: 4h of beam studies + 2h beam restoration):
- ?Safety Walkthrough (M. Dalton + trainee(s))?
- Scot to access to take out Vlad's chiller
- ?Investigate the faulty pressure sensor?
- ?Chris Carlin to fix the target controls?
- Link to runplan
Friday January 20
Past 24 hours
- Ran on amorphous radiator (250 nA) until 10am. Then, beam was taken away for RF work (high current push for Halls A and C). Beam came back around 5:30pm. We did harp scans, a BCM/FCup calibration, and then ran on various amorphous radiators during the night and early morning. ABU= 11.5h for the day
- Several accesses done during the day:
- Sasha (FADC replacement for TOF)
- Sergey
Shift Reports
Reports
- Harp scans. Sigma_y is too wide=> too wide photon beam spot (magenta). Okay for now (unpolarized beam)?
- TOF calibration (Beni), FADC replacement for TOF (A. Somov)
- Difference in Shape of Reconstructed photon beam energy with different AMO radiators (Churamani Paudel)
The main task during the RC week from 01/18-01/25/2023 was to align the diamond and start then production with linearly polarized photons. The diamond was aligned on Sunday (01/22/2023) and production started right after. The reason why alignment could not be done sooner is because of multiple issues with the accelerator. Wednesday, the beam was not available during the day for beam and RF study and a long recovery from these study: acceptable beam came back only Thursday at 1:10am. Hovanes, the expert aligning the diamond waited until 1am and left as the beam was still not there and it was getting too late to do the long work efficiently. We therefore took amorphous data in production configuration when the beam. Thursday, the beam was again taken way for RF study. The reason was that the accelerator could not reach the high currents required by the Hall A and C experiments. During Thursday night, we ran again on amorphous radiator, choosing to do one run on each of the 4 available Al. foils in order to check the dependence of the rates with radiator thickness. This was due to the rate appearing to be 30% larger than expected for our nominal current. (This was ultimately traced back to a BCM calibration problems, see below in the list of issues). Friday, the beam became unavailable again starting around 7:30am due to a vacuum issue in south linac.
The other special task done during the week (waiting for the aligned diamond to become available) was a long empty target run done during the Tueaday-Wednesday night. Its analysis shows the expected vertex distribution.
In all, ABU***
A significant issue discovered during the week was that the calibration of our BCM differed by 30% compared to the run in 2020. Discussions with Ops revealed that the BCM calibration (called BLA calibration) is not done systematically before each run period and the last one was done in 2021. We discussed with Ops to ensure that it should now be done at each start of new run period. We did the BLA calibration on Thursday, 01/24/2023. It was also discovered that the Start Counter was effectively (but not physically) rotated by about 90 degree. Smaller issues beside the usual running woes such as DAQ or FADC troubles, included discovering beam energy modulations of a few MeV due to artifacts in BPMs, the pressure sensor for the CDC producing unphysical spikes and triggering alarms (the sensor information was temporarily removed from the alarm). When it was inspected during an access, found hanging. After being put back and shielded from winds, the spikes disappeared.
