11 January 2008

RHIC Running:  Wolfram adjusted tunes to correct for large losses in Yellow at the beginning of the store. 

The emittance of the Blue Horizontal is very different from bunch to bunch.  Triggering on bucket 100 and integrating for ~50 buckets shows emittance of 5-10 pimm-mr, whereas triggering on bucket 150 gives 10-15.  Yellow vertical and horizontal shows emittances of 10-20 and higher.  Where does the bucket to bucket difference come from?

There was a long discussion of the reason for the high Yellow losses and short Yellow lifetime.  One possibility is electron clouds, and changing the number of bunches would alter that.  Turning down the voltage on the storage cavity would reduce the momentum spread in the bunches.  This study will be done with the end of the morning store.  The next store work will be made on adjusting tunes to improve lifetime.

Todd has completed analysis of his Orbit Response Matrix (ORM) data, and is ready to load the corrections.  The purpose of the ORM is to find Gradient errors.  Todd wants to load the correction.  Thomas does not want to load them on Friday.  The compromise is to load the new settings next week during the APEX when Mai Bei will take an orbit measurement before and after the load to quantify the improvement.

It is Friday, so we are looking for the Blue Noise.  Kevin is ready to look at it using the LFShottky.  Paul has contacted LIPA you are looking at noise on input power.  Todd has ideas for isolating the source of the noise.