Run Meeting: Feb 25th, 2019

Back to:

Main Page

Daily Run Meetings

halog

3:30PM Run Meeting, Counting house meeting room (200C)

RC: Cameron Clarke

Status

Control access to fix LHRS Dipole Quench

• After recovering from a spontaneous (no clear cause) RQ2 quench, 2.5 hours later we got another spontaneous L Dipole quench
• The hall will go into controlled access and Jack will diagnose the LHRS Dipole in the morning when he arrives
• After recovering the LHRS Dipole we will return to 50uA running, depending on the status of PQB studies during Monday Day shift

Experiment Updates

• Deadtime from Trigger Supervisor fluctuates a lot and seems to grow during a CODA run: https://logbooks.jlab.org/entry/3658989
• Bob Michaels adjusted the coincidence timing window by shortening T5 and T2 triggers: https://logbooks.jlab.org/entry/3659062, https://logbooks.jlab.org/entry/3659071
  • 10 uA, we see a large increase in relative "good" T6s vs. total including accidentals, but this may just be because we were at 10 uA where accidentals are rarer: https://logbooks.jlab.org/entry/3659071
  • We don't see the expected reduction in T6 scaler rate: https://logbooks.jlab.org/entry/3659238, https://logbooks.jlab.org/entry/3659266
  • A number of plots will need adjusted now that the data looks different (starting in run 4348), so time should be allocated to paying attention to plots, old and new, during the daily meeting: https://logbooks.jlab.org/entry/3659137
• Sci Fi testing (many more log entries precede this one): https://logbooks.jlab.org/entry/3659086
  • This was simultaneous with DAQ timing change, see log entry summarizing both sets of extra activities here: https://logbooks.jlab.org/entry/3659117
  • An access was taken to reboot the raspberry pi connected to the motion control system. Possible causes of network failure are internal clock issues, or possibly a bad serial connection to the motion controller: https://logbooks.jlab.org/entry/3659121#comment-20384
• RQ2 magnet quenched (summary https://logbooks.jlab.org/entry/3659232): https://logbooks.jlab.org/entry/3659148
  • Lost a few hours while working with Matt and Jessie to bring the magnet back with some considerable effort: https://logbooks.jlab.org/entry/3659207
  • Jessie's note that the magnet should be treated carefully: https://logbooks.jlab.org/entry/3659218
  • After coming back up the regulator is still not hitting the exact set point, see achieved current readback here: https://logbooks.jlab.org/entry/3659223
• L Dipole quenched at 3:30 AM (after 2.5 hours of good production during Owl, after a couple of hours of good production during Swing surrounded by sci fi, magnet trips, and DAQ tuning accesses): https://logbooks.jlab.org/entry/3659238
  • Mode of failure not clear: https://logbooks.jlab.org/entry/3659291
  • Hall A will go up to controlled access and Jack will repair this magnet (and probably look at a number of other magnets as well): https://logbooks.jlab.org/entry/3659292

Plan for Monday

• Attempt to bring the LHRS Dipole back online as fast as possible to take advantage of beautiful 50uA running
• Continue production data on Tungsten 2.8% target at 50uA, and move higher if possible.
• Possibly (though still under discussion) take data during Monday Beam Studies Day shift if it takes place. Parity Quality Beam studies would be performed during Day shift and should not affect heavily the quantity or quality of beam delivered to the tungsten foil target.

Slides/Links

MCC scheduling Whiteboard: http://accboard.acc.jlab.org/

APEX wiki page: https://hallaweb.jlab.org/wiki/index.php/APEX

Bluejeans connection information

To join the Meeting: https://bluejeans.com/256205934

To join via Room System: Video Conferencing System: bjn.vc -or-199.48.152.152 Meeting ID : 256205934

To join via phone : 1) Dial:

  +1.408.740.7256 (United States)
  +1.888.240.2560 (US Toll Free)
  +1.408.317.9253 (Alternate number)
  (see all numbers - http://bluejeans.com/numbers)

2) Enter Conference ID : 256205934