[Halla_running] [EXTERNAL] RC Update -- Wednesday 11/24 [resend]
Brad Sawatzky
brads at jlab.org
Thu Nov 25 12:09:39 EST 2021
This RC update was sent out Wed afternoon but seems to be stuck in the
sbs_running moderation queue.
The full version (probably with better formatting and working links) can
be found here:
https://logbooks.jlab.org/entry/3949555
-- Brad (outgoing RC)
========================================================
RC Update -- Wednesday 11/24
========================================================
Lognumber 3949555. Submitted by brads on Wed, 11/24/2021 - 16:22.
Logbooks: HALOG
Backlinks: Hodo RF status update
Accelerator and Hall Status
Configuration change to SBS-11 completed during Tuesday DAY shift
LV cable got pulled out during changeover [1]; fixed, but something to watch/check after next config change
Accelerator worked on the pass change through Swing into Owl, got some beam into the Hall mid-Owl shift
Had difficulties completing the Raster and Beam position checkout. Possibly due to optics issues downstream of the raster in the A-line [2], [3]. Under investigation during day shift
Moller quads had an issue cycling -- now fixed [4]
DAQ latencies noted on the GEMs seem to be global and caused issues with data taking throughout the night
It is still unclear why the latency changed [5], [6], but they are being adjusted based on what we are seeing this morning. See more detailed notes in the DAQ sub-detector discussions
Had some trouble with BBhodo HVs [7]
Steve suggests a power cycle of the crate may help -- requires escorted access
Cryo flow to target was found to be constrained last night
This did not impact the program and was corrected this morning.
Ran into a few computer related issues during Tuesday swing, now corrected [8], [9]
4th pass separator issue will be worked on today (Wednesday)
Original 4th Pass IOT ("IOT3") has been declared unrepairable (for now)
Plan is to move 2nd Pass IOT up to 4th (then move it back later in the program) [10]
This primarily impacts Hall C at this point, but there will be downtimes associated with reintegration and tuning once repairs are completed.
Run Plan for Wednesday--Thursday
This will be updated as we better understand what needs to be redone with corrected readout latencies.
We should be able to complete the 'Initial Beam steer-up', raster and beam position checkout this morning.
The SBS-11 Runplan (PDF) document is on the DocDB. Please update the file there if needed.
Position + separation of protons and neutrons for SBS11 (Bdl = 1.6 T.m)
[Complete] Beam restoration to the Hall(MCC driven program to get beam to the dump)
BB Sieve is IN
Ensure target is OUT
GEM HVs OFF
SBS, BB Magnets OFF
All other systems should be ready to go
After initial steer-up into Hall is complete (call Don Jones if you have issues during Swing/Owl or David Flay during the Day Phone Numbers)
Verify beam profile with Harp scans
Determine raster size and positionon target
When complete be sure to make a halog and update the whiteboard with the new raster and beam position numbers
Inform the RC when we get here. The plan will be to stop beam to Hall A and allow OPS to work on the 4th-pass line and RF separator system. We will stay in Beam Permit and retake the BBCal cosmics runs (below).
[Complete] Take BBCal cosmics data with magnets on to get HV settings established when above steering/raster checks are complete. (Call the RC)
Turn on BB (750A) and ask MCC to ramp SBS to 2100A
Ensure all detector HVs are ON, set BBCal threshold for Cosmics (~200 Hz), take 500k triggers
Keep beam out of the Hall until this is completed
Call MCC and ask that they complete their procedure to ramp SBS to production currents (2100A pos) and adjust correctors
This may require ramping BB to zero (ask them)
Verify beam position is still where you want it (centered on target)
Ask MCC will to complete Ion Chamber calibrations on LD2
'Thin' target ion chamber calibration should be complete Wed OWL (covers carbon foils, dummy)
Prep for GEM/Optics checkout
Contact GEM expert (on whiteboard) to support the GEM checkout program
Contact Holly and Andrew [call numbers on whiteboard] as well, if this starts before midnight
Turn GEM HV back ON; Ensure other detectors are ready to go.
Initil threshold settings for BBCAL and HCAL
BBCAL threshold ~0.5 GeV (readback is: -100 mV)
HCAL threshold ~0.5 GeV (readback: -80 mV)
Optics Runs for SBS-11
Zero Field Alignment
SBS OFF, BB OFF, Sieve IN
single C foil target
BBCAL threshold 0.5 GeV (-100 mV); adjust threshold/beam to get a ~3 kHz of rate
I = 5 uA
30 min of beam on target
Vertex and Angle Reconstruction 1/2
SBS ON (2100A pos.), BB ON (750A neg.), Sieve IN
5-foil Optics target
BBCAL threshold 0.8 GeV (-160 mV)
I = 20 uA
60 min of beam on target
Vertex and Angle Reconstruction 2/2
SBS ON (2100A pos.), BB ON (750A neg.), Sieve IN
4-foil Optics target
BBCAL threshold 0.8 GeV (-160 mV)
I = 20 uA
60 min of beam on target
Escorted Access to take Sieve OUT(needs trained personnel!)
Call RC ~1 hour before you will need to do this (Brad, Bill, _???_ are authorized to move sieve)
Low current GEM runs
SBS ON (2100A pos.), BB ON (750A neg.)
BBCAL threshold set to establish sufficient rate for a GEM efficiency HV scan; Adjust threshold to get to a few kHz of triggers
1 uA on LH2 target
Take 7 ~5 min long runs with different GEM HV settings for quick voltage scan
GEM expert driven ONLY (ensure GEM expert on shift; or call RC if not sure)
Voltages: 3653, 3608, 3564, 3519, 3475, 3430, 3385
Confirm Production Threshold Settings in BBCal and HCal
GEM Rate Study
Ensure GEM HVs are back at standard settings; detectors should be at Production settings
SBS ON (2100A pos.), BB ON (750A neg.)
BBCAL threshold 2.0 GeV (-400 mV) -- want a nominal 100k triggers/run
LH2 target
I=1 uA ; take 1 30min run
I=15 uA ; take 1 30min run
I=5 uA ; take 1 30min run
I=1 uA ; take 1 30min run
Move to Production Running cycle
SBS ON (2100A pos.), BB ON (750A neg.)
BBCAL threshold 2.0 GeV (-400 mV)
HCAL threshold ~0.5 GeV (-80 mV)
Goal: HCAL calib
LH2 Target; I = 15uA
10M triggers (nom. 1 hr)
Goal: Production
LD2 Target; I = 8uA
40M triggers (nom. 4 hr)
Goal: HCAL calib
LH2 Target; I = 15uA
10M triggers (nom. 1 hr)
Goal: Production
LD2 Target; I = 8uA
30M triggers (nom. 3 hr)
Goal: Production/Dummy
Dummy Target; I = 15uA
2.5M triggers (nom. 0.5 hr)
This nominally takes us to Friday 11/26 in the SBS-11 Runplan (PDF) document. Progress will be reassessed and subsequent runplan updated as needed.
Upcoming shift schedule issues https://misportal.jlab.org/mis/physics/shiftSchedule/?experimentRunId=GMn-2021
Several open TO positions starting Nov 26 (Bill H. picked up shifts on 24,25)
Reminders / Notes
Role sharing between SL and TO was discussed
TO should support the SL wherever possible while still keeping primary focus on the target
Beam Time accounting; Shift Checklist tasks are low-hanging fruit
Suggestion is to have TO start/stop runs and maintain the Run Log spreadsheet?
Run plan communication / documentation will be 'officially' documented on the Daily_Meetings#RC_Meetingspage
Don has made the Run Coordinator 'Run Plan / Report' page more visible on the wiki (and nicely formatted it)
Subsystem Updates
Hall A left side camera not responding (can't switch to it) [11]
HV Questions/Issues
BB hodoscope HV issues [12] (Steve, Ralph?)
HCAL HV status display glitch? [13] -- Cause understood. Due to 'Crate OFF' button being used. Largely cosmetic
HCal:
Present data on HCal detector calibrations (timing, energy calibration and uniformity over acceptance, coordinate resolution) at upcoming meeting
Working on clustering in SBS offline
Will be using old HVs for SBS-11 startup
BBCal:
New HV settings made for upcoming BB/SBS on/off settings
Contact BBCal experts [Arun] to load these and monitor BBCal performance during beam restart
Cosmics runs in SBS-11 configuration with magnets on: [14]; significant fringe field gain suppression in PMTs
HVs adjusted and uploaded [15]
Parts arrived for PMT dry-air flushing system; needs SSG support
Timing hodoscope:
Working on RF alignment
Rachel gave a status update online and will post to the halog
Been working through analysis related issues; making progress; several issues remain in presentation
Mark suggested he may need to write a new class to handle the RF time and make it easier to work with within the analyzer
Grinch:
Study of LED data taken under different BB+SBS conditions underway
Maria/Todd/Bradley will be taking some more opportunistic LED pulser data tonight (Monday)
Status update on LED data to Halog was requested
GEMS:
GEM experts will be monitoring the gas bottles over the holidays (should be fine, but extra eyes will help)
GEM HV Cosmic Scan Status
No analysis of these runs yet -- many had bad latency; may not be useful...
Work continues on calibrating/understanding the new GEM layer
Andrew reports things seem to be generally working, but some issues still being worked on
Still investigating the following: large number of fake tracks; possible issues with pedestal suppression, or perhaps indication of cross-talk; unclear... (this hypothesis is still under test)
GEM "HV-off" cosmics data are on disk -- not clear if it has been looked at (may help disentangle potential cross talk sources)
DAQ latencies issues noted in the GEMs seem to be global and caused issues with data taking throughout the night
It is still unclear why these changed [16], [17], but latencies are being adjusted based on what we are seeing this morning: HCAL, GEM, UV GEMs, BBCAL, BBHod, BBGrinch seem to be OK now
Beamline:
David F is looking at scaler sanity checks with Paul
DAQ:
Need electronics, timing diagrams that represents 'as-built' system
Latency shift was discovered to be common to entire DAQ
Seems to have changed around the time the ROLs were updated; which was around the time of some library updates
Latency configurations seem to be a mess based on comments in Slack (scattered across many files, interactions between global and 'local' settings, etc)
At minimum, this should probably be documented on the wiki?
Replay analysis:
GEM work is ongoing (see above)
Eric working on end-of-run report file output along with Dave F.
Would be great to summarize total Charge on target, 'good event' statistics, as well as summarizing efficiencies and other QA related parameters?
Probably most useful for full replays? (Online histo display should cover most/all of what the shift crew need to monitor already?)
Online analysis golden runs -- what do shift crew check run-by-run?
Generate a stripped-down set of plots for shift crew monitoring; experts can use a different Panguin config with a full set of plots?
Plan for full analyses on Farm?
This seems to be one of the items holding up more complete analyses of prior data
Sounds like a plan needs to be hammered out and implemented?
--
Brad Sawatzky (he/him), PhD <brads at jlab.org> -<>- Jefferson Lab/ Hall C/C111
Ph: 757-269-5947 -<>- Fax: 757-269-5235 -<>- Pager: brads-page at jlab.org
The most exciting phrase to hear in science, the one that heralds new
discoveries, is not "Eureka!" but "That's funny..." -- Isaac Asimov
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