RC meeting and Run Plan, Friday Sept. 8, 2023
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RC Meeting Information
Time:at 3:30pm today
- Location: Counting house conference room
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Readiness for Beam
- CG: beam restoration to hall A projected to start swing Tue Sept 12. We will need to have a shift crew starting on Wed Sept 13th.
- SSG only has the Moller Target to check (everything else done).
- ZR: plan to do checklist on Tue (everyone out of the hall by lunch)
Beamline readiness: beamline quads and harps, bcms, bpms, ion chambers (Ciprian Gal)
- Daniel Moser: Beam plans for reviving the target protection systems (the position locks and ramp rate) in place (Bill will review).
- Beam current limit: 45uA.
For each subsystem we ask that the responsible person go over the following points:
- The overall status of your subsystem
- Will your subsystem be ready well before Hall lock-up on Friday or at the latest by Monday morning?
- Does your system being ready depend on your team only or are outside resources required?
- HCal (Jiwan Poudel)
- Bigbite (Arun Tadepalli)
- Provakar: BBcal is working
- Target cell status(Arun/Gordon)
- Field measurements completed by 1pm today
- Plan was to install the rest of the targets (reference cell on site)
- over the weekend plan to do polarization checks
- Target laser status (alignment, polarization, power etc)
- last step remains to use the alignment laser to get the ladder set up (planned for Monday)
- Counting House Alarms (Bill Henry)
- Bill tested the alarms and instructions for shift crew response in the wiki (needs further revision?)
- DAQ (Alex Camsonne)
- fixed the SBS, LHRS crate
- the rack for the TS tripped off -> will move the TS crate power to do further checks (today). Plan to leave the DAQ running over the weekend
- Paul K checked the helicity and everything looks fine
- GEMs (Holly Szumila-Vance)
- Vimukthi: fixed issue with SBS and BB GEMs (LEMO cables was the culprit - logbook still needs to be made) => check on this
- AC: from DAQ point of view it looks ok.
- ChG: Ellen has a mass flow controller and needs to find some time to install it (not a show stopper - gas mixture changes from 79%Ar to 70%) => Chandan can also change the MFC
- Target magnets and measurements (Bogdan W. and Bill Henry)
- WH: done.
- Moller polarimeter (Don Jones)
- Target motion not working (Ellen looking into it)
- we want to do at least one measurement at the beginning; all systems that could be checked now (besides the target) work as expected
- magnet not cold; expect to get it there end of week (over the weekend)
- SBS magnet and Bigbite magnets ramp and hold?
- seems to work; acid flush rescheduled for the long down
- Corrector magnets:
- tested by Ellen and signed off on the HCO list
- AC: fixed the HV power supply so it should be fine to turn on; already took cosmics but didn't look at the data
Preliminary run plan
- First, bring the beam safely into the hall (Beam recovery procedure - Jiwan and William Henry https://sbs.jlab.org/wiki/index.php/HOW_TOs#Beam_Recovery_Procedure)
Q: At what stage is the SBS turned ON? WH: will post links to the corrector checkout
- BigBite/single foil location reconstruction (~20 mins?) - BigBite + HCAL detector experts on call consulting analysis experts like Andrew/Sean (magnet on)
- Target performance assessment by target group - Arun (Why hasn’t the target reached xx% polarization?), tell us when we will get there (Target group - Arun) and plan for those hours in between
- Take production data!
List of items in case target isn’t ready:
- Take data on reference cell at 10 atm H2 (portions that add up to 1 day)
- BigBite Sieve slit
- with 8 carbon foils and take optics for 1 hr at 40 uA (Sean/Andrew - confirm time)
- 1 hour for single foil (magnets off) => Chance BBcal HV setting to appropriate values
- Moller measurement depending on availability of people and results from Hall C
In person: Ciprian G, Alexandre C, Hanjie L, Mark J, Chandan G,
Online: Bogdan W, Jimmy C, Sanghwa P, Don J, Ole H, Jack J, Saru, Todd, Brian M, Xinzhan B, Gordon C