Minutes of the Dec 3, 2004 Tevatron Dept Meeting

1. Dept news: a) Sasha Valishev is going back to Russia after 1 year term
as a Guest Scientist - we are thankful to him for contributions in the SL
progress, optics and beam-beam studies, hope he'll be back; b) from
various meetings this week - 1st OTR will be ready for installation in
A150 line by Xmas; full scale new BLM prototype - by Feb'05; FWs and SBD
upgrades (OACs) - by Xmas.

2. Dean summarized start-up: started on Sunday, spent 3 shifts on single
turn because of vacuum valves stuck in beam at D17 and E11;  smoothed
orbits 150 to LB (correctors OK); significant changes in coupling on ramp;
in general, coupling is greatly reduced, SQ circuit current reduced after
reshimming to 1.1A (vs 2.8A before shutdown and 0.9A expected); "old" and
new separators and polarity switches checked with the beam; started helix
work at 150; over weekend we'll finish helix work on the ramp and squueze,
will do instrumentation checks (dampers, kickers, TEL), reverse injection.
Expect first pbars next Monday - for test purposes, first shot Tuesday.

3. Mike McGee on CDF girder support work: two columns installed, 12 Hz
oscillations gone, long term stability under investigation; LVDTs
installed on both sides and show <10 um vertical motion of the girder
(acceptable) and 25-50 micron in H-plane (worrisome), lateral invar
supports should probably be removed on B-side.

4. Todd looked into orbit vibrations and found that though 12 Hz line
(10's of microns) completely gone (0.1 um or so), rms amplitude is about
the same as before shutdown (40-80 microns in both planes, p-to-peak);
several times he saw significant enchancement of orbit vibrations
amplitude after squeeze (over 100-200 microns at 3- and 33 Hz) and then it
dissipates. Jerry mentioned these frequencies are close to synchrotron
lines and that uncoalesced bunches are dancing.

5. Alex Koschik observed significant change in behavior of dancing
bunches: in 2003 uncoalesced bunches were dancing as a whole, while now
there is a stable core (>50% of beam) and very narrow sub-bunch
oscillating around. There was a discussion whether it's a novelty - Alvin
reported that he saw dancing sub-bunches in the Tev in last century.

6. Alex also pointed out that according to measured frequency of the
fundamental mode of Tev RF cavities we should see Robinson instability at
150 and stability at 980 (while we seem to be stable in both cases) - to
be investigated further.

7. Jim Steimel and Bob Webber reported progress with A3 BPMs (new ones) -
all of them datalogged, they are still under commissioning though report
smth reasonable.

8. Alvin estimated T:IBEAM lifetime of an uncoalesced beam at 980 GeV
(12/01/04) to be about 2100 hrs (too good to believe... last
best time was 600-1000 hrs).

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