07 December 2007

RHIC Startup: Two RF cavities tripped off last night, so RHIC filled with just a single cavity.  Then that cavity tripped off, leaving just the common cavities.  It was a very good fill.  The RF Igniters (Ignitrons) must be warm enough to fire, and the AC in the RF buildings is too cold. 

Nominal per bunch intensity for good running is 0.6E11 d per bunch and 1E9 Au per bunch

STAR report high background rates, which seems to correlate with vacuum levels.  PHENIX also sees high background rates, although primarily in the Blue side. 

Do steering studies during the day today, but otherwise just run good stores all day and weekend.  Experiments would not take data during the study, but it would not effect the store, and physics running could continue before and after.  Doing a vernier scan will allow both experiments to check how much of the background rates are due to collisions. 

Chromaticity was measured up the ramp.  Two sets of measurements of tune, with the radial offset on and off, to give the chromaticity. 

PHENIX wants to do a zero-field run at the end of this fill.  It was agreed to by RHIC and STAR.

Mike Brennan wants to bring on the Landau cavities for the next fill.  It was agreed to.