Minutes of the Tevatron Department Meeting Friday meeting, April 26, 2002 1. Vladimir announcements: Thursday meeting of the Tev Dept Physicsts, The Accelerator Advisory Committe Meeting May 12-13 Activity to raise the bar for the TeV abort from one RF station trip to two. He also summarized P. Lebrun's presentation at the Run II mtg: a) there seems to be 4% of DC beam at injection; b) satellite bunches carry 2-16% of intensity; c) MI bunch length at 150 GeV is 0.4 - 0.6 ns shorter than TeV sigma at injection. 2. Jerry reported two luminosity records last week: 15.9e30 in store 1217 and 16.4 in store 1240. Luminosity lifetime is slightly better than a month ago (15-17 hours instead of 12-14 hours) probably because of lower pbar tunes (since about 2 weeks ago). Now the lifetime for bunches #1 and #12 is about the same as for others (before - it was much better than for #2-11). He observed an unexplained increase of initial p and pbar bunch length from store to store - some 10% for the four stores. 3. Mike Martens informed us about the addition of a breaking point very early at the ramp (at 153 GeV). First attempts to correct tunes wobbling there were not conclusive. He will continue tune/coupling correction at the ramp next week. 4. Octupoles can be used for improving p-lifetime at 150 GeV, claimed Yuri, but the first attempt last week was unsuccessful simply because we were unable to establish a 36 x 12 store. 5. Dean Still tried to tune up quads in the P1 (injection) line, possibly saw some emittnace improvement but it was not very conclusive, so no changes were left in place. 6. Vladimir did some homework analyzing CDF data on the size of the luminous region vs. z. His fit gives beta* of some 40 cm (vs 35 design), and effective emittance some 21 pi mm mrad (sounds reasonable). He also found good agreement beween Mokhov-Balbekov formula and loss rate observed due to F11 vacuum pressure rise. 7. Todd Johnson installed a thermocouple on the ferrite absorber of the F11 resistive wall monitor. He found that the pressure rise to about 2e-6 Torr few hours into each store, did not disappear after the recent 17 hr bakeout. The pressure rise correlates with 10C temperature rise. 8. There was a lengthy discussion whom to award with beam studies time as we had too many requests for studies this week. 9. At the very end of the meeting Stephen Pordes compared Flying Wire scans at the beginning and at the end of one of the recent stores: result- after 15 hrs hor emittance grew from 19.3 to 28.9 (p), 19.4 to 25.4 (pbar) pi mm mrad vert emittance grew from 23.8 to 29.8 (p), 21.5 to 25.8 (pbar) pi mm mrad dP/P grew from 1.28 to 1.47 (p), 1.13 to 1.16 (pbar) e-4 rms