Minutes of the 22 Apr 2011 Tevatron Dept Meeting

https://indico.fnal.gov/conferenceDisplay.py?confId=4398

* Weekly Operations Summary (Dean Still) - The Tevatron delivered 96 pb^-1 over
the past 2 weeks. There have been 16 HEP stores with initial luminosities
between 211 and 368 ub^-1/s.  Abort kicker prefires killed one store
prematurely and caused another shot to be lost before collisions.  A faulty
quench protection electronics cards caused one store loss, and lightning ended
another.  Abort kicker woes caused ~2 days of downtime; thyratron tubes were
swapped/replaced in 2 tanks, but the real problem was likely a broken HV cable
found during tube replacement.  Other maintenance included a cryo compressors,
power amplifier for an RF station, current readback cards for a low-beta
quadrupole, repair of electronics damaged by lightning.  Orbit smoothing and 
tune-ups were done to improve beam efficiency through the squeeze and reduce 
emittance blow-up when initiating collisions.

* Electron Cloud Study (Xiaolong Zhang) - Xiaolong is reviving electron cloud
observations in the Tevatron to test a new Retarding Field Analyzer detector.
Using high intensity uncoalsced protons at 150 GeV, he observed the usual 
pressure jumps in the warm straight sections, but they did not persist as long
as in the past experiments several years ago.  Beam instabilities were also
observed.  An amplifier needs to be added to the RFA to enhance the signal
output.

* Plan for Next Week (All)

   - Deliver luminosity.
   - Tune Mult Calibration (Ron, end-of-store)
   - Crystal collimator (Dean et al., end-of-store)
   - Lumi leveling (Ron, end-of-store)
   - Hollow e-beam (Alex, Giulio, end-of-store)