Minutes of the 30 Aug 2002 Tev Dept Meeting 1. XLZhang will be Tevatron coordinator for one more month till Sept 30, 2002. 2. Next week Vladimir is at CERN, Ron Moore will be acting Department Head. 3. XL reviewed 4 stores since last Fri: #1686 had L=13 and 4 hrs lifetime (due to pbar longitudinal shaving and transverse blowup), then there were some tune changes done at 980 and left for following stores --> three stores had L>20 and decent lifetime. 4. Jim Steimel and Tan for the first time attempted to close feedback loop of the horz bunch-by-bunch damper. They observed +10dB increase in the vert Schottky power, maybe minor (-0.001) hor tune shift, does not seem that the damper affected min (threshold) chromaticity at which coalesced bunch becomes unstable. Ideas to test: a) quantify the system noise; b) decouple well and separate tunes in order not to have x-y coupling messing the picture; c) change sign of the gain and see unstable beam - estimate is that with regular gain the increment will be some 10 ms or 200 turns; d) try to adjust loop phase manually to optimize performance; e) (+other ideas, like do experiment at 980 GeV where tune lines are more distinctive). 5. Fritz DeJongh and Dean advanced in making McGinnis C_v,h method operational: they proved once again that the method works and reported C_v,h are close to measured by usual method (df), the process is now partly automated and takes about 2 min. Significant noise level was observed in the demodulated VSA spectrum (?). Future steps: a) see how it works with coalesced beam; b) at 980? ; c) will it work on ramp?; d) can it work simulateneously with longitudinal damper? 6. Though Vic or Jerry were not at the meeting, several attendants (Stephen, Jim S, Valery) commented BLT situation: a) McGinnis provided fake beam signal and it has become clear that there are data acquisition errors; b) 20 dB attenuators were installed on proton side cables but it's unclear yet whether they help or not; c) some progress is expected in 1 week. 7. Valery did not get time for A1 line measurements - it has to be given to him at the very first occasion. 8. Dean was asked to change the Tev tables in order to have increased RF voltage at the first half of the ramp. That's been done, but recent 12x0 store has shown that losses on ramp are somewhat larger that usual (instead of expected reduction), so, all the changes are taken back (=>RF voltage is constant during the ramp). 9. Peter Ivanov summarized recent investigation of the transverse instability: it looks like weak head-tail, modes m=0,1,2 were observed, beam is stable (typical Tevatron beam parameters) at 150 GeV if C_v,h>6, instability at 2