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| − | = Wednesday January 24 =
| + | '''Run Coordination report for the week from 01/18-01/25/2023 (Alexandre Deur).''' |
| − | === Past 24 hours ===
| + | |
| − | * Beam study, with Hall D access. Then, production on diamond. ABU= 12.2 h for the day.
| + | |
| | | | |
| − | === Shift Reports ===
| + | The main task during this RC week was to align the diamond (JD70-103) and start 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 multiple issues with the accelerator. For the first day of the week, Wednesday Jan. 18th 2023, the beam was not available during the day due to beam and RF studies, and a long recovery from these studies: acceptable beam came back only Thursday at 1:10am. Hovanes, the expert aligning the diamond, waited until 1am and left since the beam was still unavailable and it was getting too late to start to do the long work of diamond alignment efficiently. We therefore took amorphous data in production configuration once the beam came back. Thursday, the beam was again taken way for RF study because the accelerator could not provide the high currents required concurrently by the Hall A and C experiments. The beam came back around 17:30. Hovanes checked if he could align the 0/90 directions of the diamond, which he hoped could be quick since they were already aligned for the CPP/NPP experiments. However, it happened to not be the case and that the alignment will need to be redone from scratch. Since it was getting too late for such task, diamond alignment was postponed again. Thus, during Thursday night, we ran again on amorphous radiator, choosing to do one production run (2h) on each of the 4 available Aluminum foils. This was to check the dependence of the rates with radiator thickness to try to understand why detector and PS rates counted 30% higher than expected for our nominal current. (This was ultimately traced back to a BCM calibration problem, see below in the list of issues). Friday, the beam was unavailable again starting around 7:30am due to a vacuum issue in South Linac. The beam came back Saturday at 2am. Hovanes was not available for Diamond alignment on Saturday, so the task was postponed to Sunday and we did production on the amorphous radiator of the goniometer until Sunday 9am. At that time, Hovanes started diamond alignment. It was relatively quick, finishing by Sunday 17:30. Then we started the GlueX-II data production, cycling over 0/90/45/135/amorphous and continued until the end of my RC tenure Wednesday, Jan. 25th. There was a pause on Tuesday due beam studies scheduled for the day (6h). The coherent peak spectrum displays a sharp edge and relatively high (~40%) maximum photon polarization. |
| − | * [https://logbooks.jlab.org/entry/4116249 Day shift summary]
| + | |
| − | * [https://logbooks.jlab.org/entry/4116506 Swing shift summary]
| + | |
| − | * [https://logbooks.jlab.org/entry/4116677 Owl shift summary]
| + | |
| − | * [https://logbooks.jlab.org/entry/4116888 Early Riser shift summary]
| + | |
| | | | |
| − | === Reports ===
| |
| − | * During Access, a certain number of problems were fixed:
| |
| − | ** [https://logbooks.jlab.org/entry/4116277 The TAGH HV crate power was cycled (A. Somov)] (See original problem [https://logbooks.jlab.org/entry/4116043 here])
| |
| − | ** [https://logbooks.jlab.org/entry/4116279 Target remote control was fixed (C. Carlin)]
| |
| − | ** [https://logbooks.jlab.org/entry/4116374 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 [https://logbooks.jlab.org/entry/4116505 it froze again] until this morning, 6:24am. [https://logbooks.jlab.org/entry/4116955 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.
| |
| − | * [https://logbooks.jlab.org/entry/4116246 Diamond orientations are consistent with 2020 (Alexander Austregesilo)]
| |
| − | * [https://logbooks.jlab.org/entry/4117016 Energy monitoring for Winter 2023 GlueX-II run]
| |
| | | | |
| − | === Issues ===
| + | Beside diamond alignement, the other special tasks done during the week were completing the detector check-out and calibrations (the detectors are working well) and, while waiting for the diamond to be aligned, to do a long empty target run (done during the Tuesday-Wednesday night). Its analysis shows the expected vertex distribution. |
| − | * [https://logbooks.jlab.org/entry/4116334 Start counter 96 degree rotation in cabling or software space (Simon)]
| + | |
| − | * [https://logbooks.jlab.org/entry/4116427 DIRC LED TDC missing (David Lawrence, Justin]
| + | |
| − | * [https://logbooks.jlab.org/entry/4116199 TOF timing (Beni)]. Later [https://logbooks.jlab.org/entry/4116298 fixed by Sean].
| + | |
| − | * [https://logbooks.jlab.org/entry/4116959 Long DAQ problem:~1.5h (Alison Laduke/Sergei Furletov)]. See also [https://logbooks.jlab.org/entry/4116888 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.
| + | |
| − | * [https://logbooks.jlab.org/entry/4116888 A request for the kitchen lights to be fixed should be submitted next time there is beam downtime.]
| + | |
| | | | |
| − | === Plans ===
| + | In all, the useful beam time (ABU) for the week was 47h, and we lost about 8h due to problems on our side (BANU), largely due to usual overheads (changing radiators/diamond orientations and DAQ stop/start). |
| − | * 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 =
| + | Issues discovered or that arose during the week (beside the usual running woes such as DAQ or FADC troubles) were: |
| − | === Past 24 hours ===
| + | * The calibration of our BCMs differed by 30% compared to the run period of 2020. Discussions with Ops revealed that the BCM calibration (called BLA calibration) is not done systematically before each run period and the last calibration was done in 2021. We discussed with Ops to ensure that it should now be done at each start of a new run period. We did a BLA calibration on Thursday, 01/24/2023; |
| − | * Production on diamond. Trippy beam, but good availability. ABU=16.2h for the day
| + | *The Start Counter is effectively (apparently not physically) rotated by about 96 degree. At the time this summary is being written (01/29/2023), the issue is not solved or fully understood; |
| − | | + | *Loss of communication with the target: for a few days, the target could only be could monitored, but not controlled remotely (e.g., switch empty <=> full). This was not a problem since there was no need to empty the target during that period; |
| − | === Shift Reports ===
| + | *Loss of communication with the TAGH high voltage crate; |
| − | * [https://logbooks.jlab.org/entry/4115595 Day shift summary]
| + | *DIRC LED TDC missing and the DIRC disconnecting from the DAQ; |
| − | * [https://logbooks.jlab.org/entry/4115786 Swing shift summary]
| + | *NMR probe readout failures; |
| − | * [https://logbooks.jlab.org/entry/4116022 Owl shift summary]
| + | *Beam energy modulations of a few MeV at most, due to artifacts in BPMs; |
| − | * [https://logbooks.jlab.org/entry/4116083 Early Riser shift summary]
| + | *The pressure sensor for the CDC producing unphysical spikes and triggering alarms. The sensor information was temporarily removed from the alarm. When the sensor was inspected during an access, it was found hanging. After being put back and shielded from winds, the spikes disappeared. Nevertheless, a spare was bought and will replace the current sensor. |
| − | | + | |
| − | === Reports ===
| + | |
| − | * [https://logbooks.jlab.org/files/2023/01/4115541/Hall%20D%20Electron%20Beam%20Harp%20Scan%202D%20Fitting%20Tool.pdf Beam profile from Harp scan done Monday morning looks good]
| + | |
| − | * [https://logbooks.jlab.org/entry/4115569 Coherent peak enhancement fit for 2023 (Justin)]
| + | |
| − | * [https://logbooks.jlab.org/entry/4115527 Start Counter performance (Beni)]
| + | |
| − | * [https://logbooks.jlab.org/entry/4115731 Rates comparison for GlueX, PrimEx and CPP/NPP (Alexandre D.)] | + | |
| − | * [https://logbooks.jlab.org/entry/4115667 Start Counter detector walk (Beni)]
| + | |
| − | | + | |
| − | === Issues ===
| + | |
| − | * [https://logbooks.jlab.org/entry/4116043 Tagger Hodoscope HV communication problem (Jon Zarling)]
| + | |
| − | * Main trigger scaler freeze goes unnoticed: [https://logbooks.jlab.org/entry/4114856 Sunday], [https://logbooks.jlab.org/entry/4116137 Monday] Can we include them in the scaler summary gui, so it is easy for the shift people to see them?
| + | |
| − | * [https://logbooks.jlab.org/entry/4115830 NMR probe not communicating.]. It started around 4pm Monday. DCCT current monitor for the tagger is also down.([https://logbooks.jlab.org/entry/4116083 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 [https://logbooks.jlab.org/entry/4115218 CBrem peak]). Then did Harp scans. Sunday ABU: 14.3h
| + | |
| − | | + | |
| − | === Shift Reports ===
| + | |
| − | * Day shift summary [https://logbooks.jlab.org/entry/4113703 Friday], [https://logbooks.jlab.org/entry/4114358 Saturday], [https://logbooks.jlab.org/entry/4114927 Sunday]
| + | |
| − | * Swing shift summary [https://logbooks.jlab.org/entry/4113892 Friday], [https://logbooks.jlab.org/entry/4114507 Saturday], [https://logbooks.jlab.org/entry/4115112 Sunday]
| + | |
| − | * Owl shift summary [https://logbooks.jlab.org/entry/4114007 Saturday], [https://logbooks.jlab.org/entry/4114730 Sunday], [https://logbooks.jlab.org/entry/4115243 Monday]
| + | |
| − | * Early Riser shift summary [https://logbooks.jlab.org/entry/4114137 Saturday], [https://logbooks.jlab.org/entry/4114774 Sunday], [https://logbooks.jlab.org/entry/4115380 Monday]
| + | |
| − | | + | |
| − | === Reports ===
| + | |
| − | * [https://logbooks.jlab.org/entry/4114903 Diamond alignment (Hovanes)]. See also [https://logbooks.jlab.org/entry/4114981 here] and [https://logbooks.jlab.org/entry/4114995 here] and [https://logbooks.jlab.org/entry/4115071 here]
| + | |
| − | * [https://logbooks.jlab.org/entry/4113672 Empty target vertex reconstruction (Simon Taylor)]
| + | |
| − | * [https://logbooks.jlab.org/entry/4113681 TAGM check] and also [https://logbooks.jlab.org/entry/4114603 here] (Richard Jones)
| + | |
| − | * [https://logbooks.jlab.org/entry/4113756 DIRC LED performance (Bill)]
| + | |
| − | * [https://logbooks.jlab.org/entry/4114222 FCAL occupancy plots (Churaman)]
| + | |
| − | * [https://logbooks.jlab.org/files/2023/01/4114183/HarpScanResultsExtraPolation_01212023_churamani.pdf Harp scan Saturday morning]. Convergence does not look very good, but we decided to run this way for now (amorphous runs).
| + | |
| − | * [https://logbooks.jlab.org/entry/4114336 cdc currents (Beni)]
| + | |
| − | * [https://logbooks.jlab.org/entry/4114884 TOF timing resolution (Beni)]
| + | |
| − | * [https://logbooks.jlab.org/entry/4115456 tagger field after power glicth (Alexandre Deur)]
| + | |
| − | | + | |
| − | === Issues ===
| + | |
| − | * 2 RC volunteers were needed (one for Beni's RC week because of his surgery, and another for Susan S's week because she had to cancel her trip to the US). Hovanes and Simon volunteered to cover the two weeks.
| + | |
| − | * Numerous pressure alarms. [https://logbooks.jlab.org/entry/4114307 Sensor problem? Since Saturday morning, instruction from Lubomir are that we should only acknowledge the alarms. No need for stoping the ongoing run.] [https://logbooks.jlab.org/entry/4114263 See also here.] [https://logbooks.jlab.org/entry/4114344 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.
| + | |
| − | **[https://logbooks.jlab.org/entry/4113855 Yields after BCM recalibration (A. Deur)]
| + | |
| − | ** Edy (Hall D Accelerator contact) has been asked to follow up on the issue.
| + | |
| − | * Target control issue. | + | |
| − | **[https://logbooks.jlab.org/entry/4113961 Target communication lost around 1pm Friday]. [https://logbooks.jlab.org/entry/4113908 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 [https://logbooks.jlab.org/entry/4113972 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 [https://logbooks.jlab.org/entry/4114519 this entry], [https://logbooks.jlab.org/entry/4114518 this one], and the comments in the [https://logbooks.jlab.org/entry/4114358 day] and [https://logbooks.jlab.org/entry/4114507 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?
| + | |
| − | * [https://halldweb.jlab.org/wiki/index.php/Run_Coordination_Meetings:Spring2023#Runplan Link to runplan]
| + | |
| − | | + | |
| − | = Friday January 20 =
| + | |
| − | === Past 24 hours ===
| + | |
| − | * Ran on amorphous radiator (250 nA) until 10am. Then, beam was taken away for [https://logbooks.jlab.org/entry/4113138 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 [https://logbooks.jlab.org/entry/4113378 ran on various amorphous radiators during the night] and [https://logbooks.jlab.org/entry/4113552 early morning]. ABU= 11.5h for the day
| + | |
| − | * Several accesses done during the day: | + | |
| − | ** Sasha (FADC replacement for TOF)
| + | |
| − | ** Sergey
| + | |
| − | | + | |
| − | === Shift Reports ===
| + | |
| − | * [https://logbooks.jlab.org/entry/4112998 Day shift summary]
| + | |
| − | * [https://logbooks.jlab.org/entry/4113173 Swing shift summary]
| + | |
| − | * [https://logbooks.jlab.org/entry/4113378 Owl shift summary]
| + | |
| − | * [https://logbooks.jlab.org/entry/4113552 Early Riser shift summary]
| + | |
| − | | + | |
| − | === Reports ===
| + | |
| − | * [https://logbooks.jlab.org/files/2023/01/4113248/harpscan20230119-1815.pdf Harp scans.] Sigma_y is too wide=> too wide photon beam spot (magenta). Okay for now (unpolarized beam)?
| + | |
| − | * [https://logbooks.jlab.org/entry/4112963 TOF calibration (Beni)], [https://logbooks.jlab.org/entry/4113076 FADC replacement for TOF (A. Somov)]
| + | |
| − | *[https://logbooks.jlab.org/entry/4113630 Difference in Shape of Reconstructed photon beam energy with different AMO radiators (Churamani Paudel)]
| + | |
| − | | + | |
| − | === Issues ===
| + | |
| − | * [https://logbooks.jlab.org/entry/4113047 Beam energy oscillation investigation (M. Tiefenback)]. Summary: Mike T. suspects the oscilations are not real but he is asking confirmation/advice from the system experts.
| + | |
| − | *[https://logbooks.jlab.org/entry/4113408 Tim W. reminder on acknowledging alarms]
| + | |
| − | * [https://logbooks.jlab.org/entry/4113027 HVB currents look high] and [https://logbooks.jlab.org/entry/4113590 follow-up] (Naomi)
| + | |
| − | * 30% increase in rates compared to Summer 2020 run period. | + | |
| − | **[https://logbooks.jlab.org/entry/4111933 Original finding by A. Somov]
| + | |
| − | **[https://logbooks.jlab.org/entry/4113029 Comparison of 2020 and 2023 for TAGH rates (A. Deur)]
| + | |
| − | **[https://logbooks.jlab.org/entry/4113193 Check that TAGH counters scale with (A. Deur)]
| + | |
| − | **[https://logbooks.jlab.org/entry/4113098 rho and pi0 yields (A. Austregesilo)]
| + | |
| − | **[https://logbooks.jlab.org/entry/4113253 BCM/FCup calibration suggested by the PD], [https://logbooks.jlab.org/entry/4113276 its results] and [https://logbooks.jlab.org/entry/4113408 follow-up].
| + | |
| − | **[https://logbooks.jlab.org/entry/4113656 the rate discrepancy after BCM/FCup calibration has been reduced by half (A. Deur)]
| + | |
| − | **[https://logbooks.jlab.org/entry/4113580 Ran overnight on different amo radiators] | + | |
| − | | + | |
| − | === Plans ===
| + | |
| − | * Thursday evening and Friday night: | + | |
| − | **Once beam come back, do Harp scans.
| + | |
| − | **FCup test of our beam dump BCM.
| + | |
| − | **Run 1h on the amo radiator of the goni (baseline for next runs below). 250 nA
| + | |
| − | **Run 2h on 0.19E-4 RL amo radiator on radiator ladder (250 nA).
| + | |
| − | **Run 2h on 1.12E-4 RL amo radiator on radiator ladder (250 nA).
| + | |
| − | **Run (until the beam is taken away in the morning) on 3.4E-4 RL amo radiator on radiator ladder (250 nA).
| + | |
| − | * Beam off starting Friday morning around 7:30am [https://logbooks.jlab.org/entry/4113148 to fix vacuum issue in south linac], until 4pm(?).
| + | |
| − | *When the beam comes back: | + | |
| − | **Harp scans
| + | |
| − | <!--**BCM comparison (~15min, invasive to other halls). PD (Joe Grames) recommends comparing (not calibrating) the Hall D MPS BCM against the injector Faraday Cup #2: To do this:
| + | |
| − | ***Turn off beam to other halls
| + | |
| − | ***Close chopping aperture to other halls
| + | |
| − | ***Send beam to FC#2, use an upstream corrector to convince oneself it is centered (max current)
| + | |
| − | ***Send current to FC#2 (record it), then pull cup and go to Hall D (record it). Repeat for several current values: 0, 50, 100, 150, 200, 250, 300, 350, 400 and 450 nA.
| + | |
| − | ***Restore the upstream corrector -->
| + | |
| − | **Production on goni amo radiator at 300 nA until Sunday morning.
| + | |
| − | * Hall access:
| + | |
| − | **Sergey F.
| + | |
| − | * Diamond alignment: Sunday morning, ~9am.
| + | |
| − | * Until then production on amorphous.
| + | |
| − | * [https://halldweb.jlab.org/wiki/index.php/Run_Coordination_Meetings:Spring2023#Runplan Link to runplan]
| + | |
| − | | + | |
| − | | + | |
| − | | + | |
| − | | + | |
| − | 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
| + | |
| − | | + | |
| − | and Friday.
| + | |
| − | | + | |
| − | 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.
| + | |
| − | | + | |
| − | 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.
| + | |
| − | | + | |
| − | | + | |
| − | === Plans ===
| + | |
| − | * Beam off starting around 10am for RF study, nominally until 4pm+/-4h.
| + | |
| − | * Hall in controlled access?
| + | |
| − | * Diamond alignment: Friday day ? (Hovanes unavailable today)
| + | |
| − | * Until Friday day, production on amorphous?
| + | |
| − | * [https://halldweb.jlab.org/wiki/index.php/Run_Coordination_Meetings:Spring2023#Runplan Link to runplan]
| + | |
The main task during this RC week was to align the diamond (JD70-103) and start 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 multiple issues with the accelerator. For the first day of the week, Wednesday Jan. 18th 2023, the beam was not available during the day due to beam and RF studies, and a long recovery from these studies: acceptable beam came back only Thursday at 1:10am. Hovanes, the expert aligning the diamond, waited until 1am and left since the beam was still unavailable and it was getting too late to start to do the long work of diamond alignment efficiently. We therefore took amorphous data in production configuration once the beam came back. Thursday, the beam was again taken way for RF study because the accelerator could not provide the high currents required concurrently by the Hall A and C experiments. The beam came back around 17:30. Hovanes checked if he could align the 0/90 directions of the diamond, which he hoped could be quick since they were already aligned for the CPP/NPP experiments. However, it happened to not be the case and that the alignment will need to be redone from scratch. Since it was getting too late for such task, diamond alignment was postponed again. Thus, during Thursday night, we ran again on amorphous radiator, choosing to do one production run (2h) on each of the 4 available Aluminum foils. This was to check the dependence of the rates with radiator thickness to try to understand why detector and PS rates counted 30% higher than expected for our nominal current. (This was ultimately traced back to a BCM calibration problem, see below in the list of issues). Friday, the beam was unavailable again starting around 7:30am due to a vacuum issue in South Linac. The beam came back Saturday at 2am. Hovanes was not available for Diamond alignment on Saturday, so the task was postponed to Sunday and we did production on the amorphous radiator of the goniometer until Sunday 9am. At that time, Hovanes started diamond alignment. It was relatively quick, finishing by Sunday 17:30. Then we started the GlueX-II data production, cycling over 0/90/45/135/amorphous and continued until the end of my RC tenure Wednesday, Jan. 25th. There was a pause on Tuesday due beam studies scheduled for the day (6h). The coherent peak spectrum displays a sharp edge and relatively high (~40%) maximum photon polarization.
In all, the useful beam time (ABU) for the week was 47h, and we lost about 8h due to problems on our side (BANU), largely due to usual overheads (changing radiators/diamond orientations and DAQ stop/start).
Issues discovered or that arose during the week (beside the usual running woes such as DAQ or FADC troubles) were:
