RC meeting and Run Plan, Saturday April 27th
Contents
RC Meeting Information
Current RC: Iuliia Skorodumina
No RC meeting today.
Useful Links
Summary
Yesterday around 1:30pm Arc1 Box Supply tripped and the recovery took until around 7pm (see https://logbooks.jlab.org/entry/4289680 and https://logbooks.jlab.org/entry/4289913). Once the beam was back we took a BB singles run on LH2 and then proceeded back to our normal production running with HCal threshold at -10 mV. We ran smoothly overnight.
Andrew Puckett analyzed elastic yield from the BB singles run we took yesterday (see his logentry https://logbooks.jlab.org/entry/4290174) and came to the following conclusions. First, the HCal threshold of -15 mV seems to be too high as it cuts up to 30-50% of good elastic events. This seems to be consistent with David Hamilton's estimations and with what we discussed yesterday during the RC meeting. Therefore, as soon as possible, we should do a new software and hardware gain matching targeting a higher overall gain for HCAL. For the time being, we will run with lower HCal threshold (-10 mV) until we figure out what to do about HCAL HV/gain matching.
Another conclusion of Andrew Puckett's study is that we might also have inefficiency from the BigBite trigger as the BB elastic yield is just about 40% of what we would expect. To better understand the situation we decided to take a test run with lower BBCal threshold (https://logbooks.jlab.org/entry/4290231).
Once we are done with the test run, we will get back to production running on LD2 at 12 uA and -10 mV HCal threshold (and BBCal threshold -395 mV). We will also need to take a 1-hour run on LH2 with the production settings once per shift.
Day shift summary (https://logbooks.jlab.org/entry/4289416).
Swing shift summary (https://logbooks.jlab.org/entry/4289899).
Owl shift summary (https://logbooks.jlab.org/entry/4289941).
Also, we urgently need a TO for the upcoming Sunday Owl shift. Please consider signing up.
We will not have RC meeting today.
Planned Access to the Hall
n/a
Accelerator
Wednesday (05/01) will be the maintenance day. MCC plans to take the beam away at 6:45 am to start working on SL.
Current Run Plan
Today we took a test run with lower BBCal threshold (see https://logbooks.jlab.org/entry/4290231 and https://logbooks.jlab.org/entry/4290326).
After the test run, we are back to our regular production running, which is LD2 target, 12 uA, and -10 mV HCal threshold (and BBCal threshold -395 mV). We will also need to take a 1-hour run on LH2 with the production settings once per shift.
See also Experiment run plans.
Current Issues
- Vimukthi and the GEM group would like to tweak high voltages for three SBS GEM modules. This will not disrupt production data taking. This is done with the intention of increasing the efficiency of those modules. See https://logbooks.jlab.org/entry/4289667 and they also want to try another setting once the beam is back.
- Bill Henry wants to turn off a few pmts in the active analyzer because they are noisy. He want to do it later this afternoon.
Future plans
- Wednesday (05/01) will be the maintenance day. MCC plans to take the beam away at 6:45 am to start working on SL.
- MCC does not plan any major beam changes up until May 14th.
