Run Planning Meeting Notes, Feb 13-Feb 19, 2020

Thursday, February 13

1. Last 24 hours
   • Accelerator down 8:00-noon, hall in controlled access
     • Beni went into hall to work on CDC boards
     • Radcon released failed goni motor from tagger hall, taken for repair
     • start counter dark pulse measurements (raw mode random triggers)
     • Lubomir adjusted FDC thresholds
     • other activities during controlled access...
   • Quick-check harp scan at 12:15pm
   • Production started at 12:30pm
   • 200M evts collected, 46 minutes ABU
   • Solenoid trip at 2:30 -- detailed report from experts
     • cause of trip -- over-temperature on PS component
     • subsequently discovered -- controller communications issue
     • solenoid will not ramp, shifts cancelled until 8:00 2/13
   • Hall currently in restricted access
     • acid flush of PS cooling loop underway, finished by noon
     • after that, diagnosis and repair of PS controller
     • if all goes well, should be able to start ramp by 5:00pm
2. Reports

Friday, February 14

1. Last 24 hours
   • 8:00-noon, hall in controlled access
     • acid flush of solenoid PS cooling loop
     • work on PS controls started around noon
     • work-around found for electronics issue
     • hall restored to beam permit at 15:00
   • solenoid current ramp started at 14:30
     • 0 - 800A, wait
     • 800 - 1000A, wait
     • 1000 - 1200A, wait
     • 1200 - 1360A, wait
     • 1360 - 1350A, then go!
     • ramp completed around 22:30
   • Production resumed at 22:30pm
   • Meanwhile, attempt at high-intensity accidentals test
     • all detector systems turned off except: PS/PSC, TPOL, TAGM
     • JD70-106 radiator, 2.1 uA
     • beam was very unstable, attempts to understand it
     • no change in gain setting of active collimator was needed
     • we think that BPMs were saturating at 2.1 uA, driving the locks awry
     • accel turned off the locks at 250nA, then ramped up to 2.1uA
     • no coherent edge was visible in TAGM at any of the 4 settings (0/90 and 45/135 PARA/PERP)
     • spent considerable time doing nudges, no change in TAGM spectrum
     • finally, decided just to take data at 2.1uA
     • one run, maybe 5 minutes of 2.1uA beam over ~1 hour period
     • alignment of JD70-106 is a mystery -- what were we doing wrong?
2. Reports
   • PS / active target / main trigger instabilities -- Alexandre Deur
     • Rates from PS and main trigger are fluctuating
     • Rates and their ratio
     • Follow-up Re: Rates from PS and main trigger are fluctuating

Monday, February 17

1. Last 72 hours
   • smooth running at 350 nA
     • no emergencies, RC phone has been quiet!
     • beam off for several hours (pass change) on Saturday
   • several monitoring plots with noted differences
     • example -- Hall-D Monitoring Plots Run 71855
2. Reports
   • Potential improvements from realignment of JD70-105 -- Richard Jones
     • argument for realigning diamond JD70-105
   • PS / active target / main trigger instabilities -- Alexandre Deur
     • another dip in the collimator transmission fraction, amorphous run -- Justin Stevens
     • systematics of PS/tagger ratio variations -- Richard Jones
     • high-resolution time plots of active collimator signals -- Richard Jones
     • Follow-up Re: Rates from PS and main trigger are fluctuating
     • raster images from active collimator (run 71845)

Tuesday, February 18

1. Last 24 hours
   • Accelerator down from 8:00am for Wein angle change
   • Opportunistic access taken by multiple workers
   • Planned work included survey crew measuring alignment related to test setup (parasitic) upstream of solenoid
     • survey sphere brought too close to magnet, broke free of mount
     • worker could see it where it ended up (upstream BCAL readout), pulled it out
     • bias voltage on that module tripped
   • Detailed report on incident and response -- Tim Whitlatch
   • Present status
     • solenoid ramped down, target emptied
     • Hall D is being swept, preparing to pull back the target
   • Work plan for today -- experts
     • target emptied, being pulled back
     • no emergencies, RC phone has been quiet!
     • beam off for several hours (pass change) on Saturday
2. Reports
   • Plan for diamond realignment -- Hovanes

Wednesday, February 19

1. Last 24 hours
   • Temporary repairs to BCAL module 26 successful!
     • Temporary workaround in place, Hall D is operational -- Mark
   • Solenoid ramped up successfully
     • Chimney 4 cold cathode gauge
   • False alarm on CDC near BCAL module 26
   • Worked on diamond spot moves, alignment during solenoid ramp -- Hovanes
     • Moved position for JD70-105 45/135
     • problems with alignment for JD70-106 found and fixed (EPICS variables not defined)
2. Reports
   • more on the normalized PS and trigger rates fluctuations
     • PS rate fluctuations in time vs position -- Hovanes
     • Rates from PS and main trigger continue to fluctuate -- Alexandre
     • Beam transmission and trigger efficiency -- Alexandre
   • TOF hit location and Tracking -- Beni
   • Integrated trigger counter update -- Alexander