Minutes of the April 17, 2009 Tevatron Dept Meeting

http://indico.fnal.gov/conferenceDisplay.py?confId=2525

* Weekly Operations Summary (Dean Still) - The Tevatron has delivered 61 pb^-1
to CDF and D0 over the past week.  There have been 9 stores with initial
luminosities between 193 and 340 ub^-1/s; pbars were limited for a couple of
days due to a problem with the Accumulator bend bus.  Two stores were aborted
prematurely: store 6966 ended after 7 hours when a vacuum circuit break for the
A3 power supply opened up; store 6970 ended after 11.4 hours when the SF
sextupole circuit tripped off (a switch with a bad connection was repaired).
A controls applications related to orbit smoothing was found to have a memory
leak that likely caused recent crashes of the Tevatron sequencer during shot
setup; the code was fixed.  Overall, it was a good week with no major problems.

* Preview of PAC Talk (Alex Valishev) - Alex showed some slides on his upcoming
talk "Recent Tevatron Operational Experience".  Beam-beam effects are not a big
problem up to our highest luminosities of 350 ub^-1/s.  Alex categorized the
cause of quenches during shot-setup; beam-induced quenches are the biggest
problem during the squeeze.  Reducing chromaticity (and smaller proton
emittances) have helped reduce the proton loss.  Alex showed an interesting
plot of how we need to make much fewer store-to-store tune adjustments at 
collisions since implementing the improved orbit stabilization.  Operational
stability has been key to the improved integrated luminosity.

* Plan for Next Week

   - Luminosity, luminosity, luminosity.
   - Electron column (Alex and Alex, proton-only)
   - Crystal collimator (Dean et al., use during normal HEP scraping)
   - Bumper as abort gap cleaner (Bruce et al., proton-only)
   - Chromaticity Tracker (Tan, proton-only)