Minutes of the Feb 18, 2011 Tevatron Dept Meeting http://indico.fnal.gov/conferenceDisplay.py?confId=4120 * Weekly Operation Summary (Dean Still) - The Tevatron delivered 35 pb^-1 to the experiments this week. There have been 11 HEP stores with initial luminosity between 67 and 345 ub^-1/s. The low initial and delivered lumi have been caused by a failure in the Pelletron which provides the electron cooling for pbars in the Recycler. Store 8488 was ended on an apparently spurious abort by TECAR (ramp control for main bus). Store 8492 ended due to a ComEd power glitch that affected the entire accelerator complex hard. Just this morning, a beam tube vacuum leak near a collimator deteriorated such that store 8510 had to be terminated so mechanical techs could identify and repair the leak. * Halo Measurement for Hollow e-Beam Collimation (Giulio Stancari) - Giulio et al. have made initial attempts to characterize the halo when using hollow e-beam collimation during end-of-store studies. When applying the e-beam to only 1 train of pbar bunches while gradually moving a secondary (stainless steel) collimator closer to the beam, they can see more intensity loss from the affected bunches - demonstrating the e-beam is removing more beam than the other collimator alone. They have also made diffusion rate measurements vs amplitude (secondary collimator position) and get results consistent with expectations. Additional studies are planned. * Plan for Next Week (All) - Resume normal operation after repairs to D17 collimators and Pelletron. - T-980 cystal collimator (Dean et al., end-of-store) - Hollow e-beam (Giuilo et al., end-of-store and a quick proton-only) - Pbar longitudinal damper (Tan, proton-only then pbar-only) - Low-Beta Quad Tickling (Jerry, proton-only) - Electron Cloud (Xiaolong, 1 hr proton-only) - Test of RF Reduction (Ron, 30 min proton-only @ 150 GeV)