Minutes of the Mar 4, 2005 Tevatron Dept Meeting

1. Dept news: a) thanks to Ron Moore for coordinating Tevatron in the
month of February... welcome, XiaoLong Zhang!; b) a DoE Run II operations
review will take place at the end of March, some of us should be prepared;
c) 8 people from Tev dept will be supported for PAC'05.

2. Operations summary (XiaoLong): 6 attempts to put stores since last Fri
ended up in only 4 stores, Lumi btw 74-92e30; 3 quenches (MDAT problems,
T:SQ tripped and during scraping); there was pbar kicker AAK1 prefire (no
store lost); 7 um Flying Wires were flown at L=80 and that seems to be OK;
RF phase instability did not develop but noisy periods occur regularly, we
drop longitudinal damper gain to ease that; there are spikes in D0 losses
(see below); high losses during the second scrape need attention (there
are 4 possibilities to reduce them); CDF IP is creeping up (by some 0.5 mm
since early Jan) - probably due to orbit smoothing, can be fixed by
correctors if needed.

3. Valery Evdokimov of D0 has shown how 0.5-1.0% pbar losses trip D0 muon
detector crates, that happened between seq.24-25 of the squeeze. Jerry
explained that a fix of tune excursion (some studies done this
week) will probably resolve the issue.

4. Yuri analyzed increments of longitudinal multibunch modes with 36
p-bunches loaded and concluded that shift of RF cavity resonant frequency
down by several 100's Hz will damp all dipole modes (in theory).

5. Tan reported nice results from his tunetracker: vertical TT is
commissioned, emittance growth due to TT is not detectable (<0.2pi/hr at
150), Hor TT tracks perfectly on the ramp, tune available in ACNET (thanks to
Ron); chromaticity measurement with TT was correct within +-1 unit wrt
standard method... still, there are several improvments to do (e.g. vert
21Mhz Schottky - an input for TT - is too noisy).

6. Jerry, Dean and Dave McGinnis revived a RF-frequency modulation method
and measured chromaticity at 150; Vahid pinged coal bunch and got correct
Q'_x,y, too (with octupoles ON).

7. Vladimir presented an idea of luminosity leveling by changing RF
voltage during the store - start at low voltage (longer bunch length) and
raise it over the course of the store : the method allows to reduce PEAK
luminosity at the start of store by 16-22%, while giving a slight increase
in INTEGRATED luminosity (because lifetime is improved due to weaker IBS
for longer bunches).


Minutes recorded by V. Shiltsev; edited by R. Moore