Subject: Minutes of Tev Dept Mtg, Dec.27 Date: Fri, 27 Dec 2002 16:32:59 -0600 (CST) From: Vladimir Shiltsev To: tevatron , annala@fnal.gov, bhanna@fnal.gov, bollinger@fnal.gov, cytan@fnal.gov, erdelyi@fnal.gov, garbincius@fnal.gov, jwalton@fnal.gov, kipster@fnal.gov, koch@fnal.gov, martens@fnal.gov, mccormac@fnal.gov, meiqin@fnal.gov, pmivanov@fnal.gov, ranjbar@fnal.gov, rivetta@fnal.gov, ronmoore@fnal.gov, shiltsev@popgtw.fnal.gov, stefanski@fnal.gov, steimel@fnal.gov, still@fnal.gov, tjohnson@fnal.gov, tsen@fnal.gov, val@fnal.gov, volk@fnal.gov, xiaoam@fnal.gov, zhangxl@fnal.gov CC: tevcc , balbekov@fnal.gov, burov@fnal.gov, cheung@fnal.gov, church@fnal.gov, drozhdin@fnal.gov, emclark@fnal.gov, finley@fnal.gov, frankz@fnal.gov, fritzd@fnal.gov, frs@fnal.gov, holmes@fnal.gov, jansson@fnal.gov, mokhov@fnal.gov, mont@fnal.gov, scarpine@fnal.gov, slaughte@fnal.gov, spalding@fnal.gov, stephen@fnal.gov, syphers@fnal.gov 1. News from Vladimir&Ron: there 'll be 2-3 shifts of studies next week (starting early morning Thursday Jan 2) and tentatively 5 shifts in the week of Jan 6, 2003 2. Store summaries by C.Y.Tan: luminosity fluctuated between 24 and 33e30 in the last 5 stores, but mostly due to number of pbars (e.g., we lost transfers, we had problems in MI, etc.) Efective emittance this week was 23-23 pi - that is a bit (1.4 pi in average) larger than week ago. In the very last store #2105, the SLite pbar emittances seems are 20% larger than in previous store though FW and effective emittances are about the same in both stores. Major issue now is 20% loss of pbars on the ramp. Tan tried to change chromaticities and tunes here and there on the ramp but made things only worse (though expectations were that if one lowers chromaticities or/and straightens tunes, then losses have to go down. He will try to smooth orbits on the ramp today. 3. Vladimir reported that pbar tune scan at the end of 2103 failed because of the 3 feeddown curcuits tripped OFF. 4. Andreas analyzed hor proton removal data and concluded that proton SyncLite tracks FW emittances very well (without offsets as in Pbar SLite channel). Emittance scaling SLHor/FWHor=1.18; SLvert/FWVert=1.45, beam size found from hor scraping results in Emittance ratio ScraperHor/FwHor=33pi/27pi=1.22 (the latter somewhat dependent on the model of scraping, 1D or 2D). 5. Vladimir reconstructed hor beam distribution function from p-removal data and found that it has a significant dip at 1 sigma (600 microns), it's more like triangular in the core, and Gaussian in the tail (1.5 to 3.5 sigma). Jim Steimel pointed that the dip might be due to bulls-eye distribution in longitudinal phase plane (bands in the beam left after coalescing in MI - seen before). 6. Possible studies : a) today (after loss of store due to kicker prefire) - smooth orbits on the ramp; measure tunes on pbar helix; b) during next stores - lower C_v,h at 153 and 163 GeV slots by little steps; c) next week - ramp loss studies; reverse injection emittances; automatic aperture scan; ping the beam and get BPM readings. [see Tan for details]