Run Planning Meeting Notes, October 21 - October 27, 2021

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Hot news

11:44 "We just got out of the tunnel. The two bending dipole magnets leading to Hall D that we worked on yesterday (which included removing the DC leads) were found misconnected, thus reversed polarity. Both have been corrected and we are (fairly) confident that beam will now transport properly.

Backstory/Long story: these magnets had been repurposed from the 6GeV era. The old ‘+’ ‘-‘ labeling on the magnets were not removed and the technicians followed what they thought was the proper convention for hooking up the leads. Unfortunately the labels were incorrect for the magnet’s 12GeV application and so the incorrect polarity. Plenty of lessons learned from this adventure.

The BPMs and viewer were also made functional. This will help to confirm the proper transport toward the Tagger."


Tuesday 26 October

  1. Last 24h:
  2. Issues:
    • BCAL noise at 10 o'clock
    • Bleedthrough
  3. Plan:
    • When the beam is expected back, call Chris Keith to watch the target fill (1h40). Make the usual checks (radiation levels & harp scans) and then continue production at 200nA.
    • Hall C BCM calibration Wed.
    • Hall A is aiming for another configuration change on Friday (might have a problem w SBS magnet).

Monday 25 October

  1. By 1:30 will know what the magnet repair plan is. There is a spare on site. It would take about 2 weeks to swap.
  2. Happenings since Friday morning:
    • Everyone seemed optimistic at Friday's morning meeting.
    • Started filling the target a little before 9:30, with Chris Keith watching, and the shift crew here.
    • We went into controlled access so that Tim could go in to do something for CPP. Sasha also needs to make an access.
    • This looked promising
    • The problem was isolated to a ground fault in magnet YBBS04.
    • Shifts are cancelled until Monday 10am. Monday 10am+ shifts are on standby. Tuesday shifts remain unaltered.
    • The target has been emptied, the solenoid is still on, and the hall is in power permit.
  3. Work done:
  4. Issues:
    • BCAL noise at 10 o'clock
    • Bleedthrough
  5. Plan:
    • VIP visit (NL & Hall B) + arc 7 magnet tests + pass change.
    • Bill asked about changing DIRC water.
    • When the beam is back, call Chris Keith to watch the target fill & then continue production at 200nA after the usual checks (radiation levels & harp scans)

Friday, October 22

  1. Last 24h: Production runs continued smoothly until 2:51pm when an arc magnet tripped. About 7pm the team looking at the power supply found that there was a short in any one of the 42 magnets downstream, they will resume work in the morning. Shifts were cancelled until 9am.
arc 7 trip
  2. Remaining issues:
    • BCAL noise at 10 o'clock
    • Bleedthrough
  3. Plan:

Thursday, October 21

  1. Last 24h:
  2. Remaining issues:
    • Tagger hodoscope time shifts
    • communication with accel. w.r.t. tagger magnet - Paul Vasilauskis (Ops group leader): "I am putting out to my staff to contact the hall if they do need to touch the magnet and am looking into adding wording to the magnet screens"
    • BCAL noise at 10 o'clock
    • Bleedthrough
  3. Plan:
    • When the beam is back continue production at 200nA after the usual checks (radiation levels & harp scans)
    • Continue running with the solenoid on & target full until Friday or later
    • Pass change for A&B Saturday morning (A->4 pass)
    • Expect downtime Monday morning for VIP tour, start time TBC probably ~7am.
    • Ops will need another maintenance day before the energy change
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