17 December 2007

RHIC Startup: New operating instructions for injecting gold beam.  Now we must just kick out the "pilot" bunch, leave three more bunches in booster.  We must always have extraction going so beam is dumped in the W-dump at all times,  Dumping beam even at low energies is a problem.

One difference between last year and this year is that last year we did not make use of early turn off.  We also forgot to turn on the dump bump a few times, bringing the beam to a bad location outside of the AGS beam dump. 

Have changes in collimator settings improved things?  The collimator work brought down several stores on Friday.

Instability re-appeared late Sunday night.  Increasing the octupole strength helped previously, but has deteriorated since.

Rebucketing in Blue has deteriorated also. 

Gap cleaning kicker in Yellow is ringing and effecting bunches outside the gap.  Angelika thinks that with stochastic cooling on, we don't need gap cleaning.  She suggests turning it off. 

Yellow abort kicker prefire brought down a store on Saturday at 12:20. This coincided with a power glitch the blew fuses in PASS, blew out an ODH sensor, tripped several radiation sensors, and

STAR sees ZDC singles rates of 2MHz.  ~60% of this is not collision related.  STAR cannot run like this.  Will need to spend some time today immediately after the morning store ends(11:00AM) to scrub the vacuum.

A crow bar fault on b4 has brought down several stores.  Don wants to hang a 16 channel data recorder on the power supply to try to catch the problem in action.  May need to swap in a replacement PS. 

There is a discrepancy between the emittance measurement that vernier scans a IPM gives.  This discrepancy has existed for years.    The emittance measured in the ATR is a factor of two larger than the results from either the AGS or RHIC IPMs.

PHENIX reports that they will need to make a brief access on Wednesday to fix communication with the MU Tracker.

PHENIX also has a broken railing on their wheelchair ramp.  It is a safety hazard.