[Halla_running] [New Logentry] Hall A Status update -- Friday PM

[brads at jlab.org]

Logentry Text:
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The accelerator continues to have difficulties that complicate beam delivery.  There have been 1 or 2 small squirts of beam, but nothing useful.

Beam loss (BLM) trips continue to be a problem in the 7S, 9S region as well at 1C12 in the Hall A arc.  I gather there are ideas on how to address those, but there are bigger problems been addressed at the moment...

The east arc heat exchanger problem was worked on for a full shift yesterday.  Some parts were replaced and the system is functioning again, but it is still somewhat marginal.  Machine recovery Thursday swing did not go well -- there were significant optics problems starting at the injector with impacts throughout the machine.   MCC spent SWING, OWL and a good part of Friday DAY working these issues.  Other issues include: a persistant 30s beam energy oscillation of unknown origin and a number of minor hardware failures.  To top it off, the CHL crashed this afternoon (recovery is presently ongoing).

On the upside, Hall A has the clear priority now and and OPS is focussed on (a) getting the machine up and running, and (b) delivering as much CW beam to Hall A as soon as they can without worring about the other Halls.  This may include turning off the RF separation and magnetically separating beam for Hall A only (which would prohibit delivery to Hall D over the weekend).

Bottom line:  Accelerator is struggling but Hall A is the priority -- we need to be ready for beam when it arrives.

[ There are a lot of empty shifts coming up early next week (and a few this weekend!) -- please sign up ASAP:  https://misportal.jlab.org/mis/apps/physics/shiftSchedule/index.cfm?experimentRunId=HALLA-FALL2014 ]

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This is a plain text email for clients that cannot display HTML.  The full logentry can be found online at https://logbooks.jlab.org/entry/3328473
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