Minutes of the June 3, 2005 Tevatron Dept Meeting

1. Dept news: Vladimir informed about recent DoE Review of US-LHC
Accelerator Research Program (LARP), as well as about beam phys meetings
on octupoles and use of new BPMs.

2. Jerry on operations: 5 stores, lumi btw 79 and 103e30 (reduced due to
pbar intensities), there was one RF station trip at 150 GeV, pbar lifetime
in stores was reduced as we moved pbar tunes recently down by
-0.002(0.004), but luminosity lifetime improved a bit; 5 studies performed
(see below), D0 losses at the end of squeeze were tolerable (again
because of smaller # of pbars).

3. Tan and Vahid compared three methods to measure chromaticity: RF (C43),
TT (tuneTracker) and HT (Head-Tail, C100) - and found that only HT
correctly tracked changes in chromaticity settings. Repeatibility of HT is
about +-0.1(H) and 0.25(V) units. Investigations needed- why C43 and TT did
not track properly (impedance? larger dP/P?). Vladimir added that C100
chromaticities measured in the last 50 stores do correlate better with
proton lifetime at 150 than C43 chromaticities --> should try to use C100
as base method for tuneup.

4. Tan also demonstrated that his BBQ tune measurement system can see
(ungated) pbars in collisions if extra 6W of H-noise excitation is
provided for the time of measurements. His TT system successfully tracked
tunes of few coalesced proton bunches on the ramp when they crossed each
other - as usual, with superb resolution --> next week he'll try to track
in real store.

5. Andreas did study dynamics with higher intensity proton bunches
(310-340e9 vs 270e9, 20% larger long emittance due to 9 vs 7 bunch
coalescing, about the same transverse emm) #10,22,34 in HEP stores. He
explained the choice of the bunches and showed that no additional
emittance growth of pbars occured at 150 GeV, losses on the ramp were ~as
normal, in one store vert pbar emittance of corresponding bunches blew up
by 4 pi, in another store - after LB pbar tune correction - by <2 pi.
After another 2 more "test" stores he will perform statistical analysis
and conclude whether higher proton bunch intensity can help to increase
integrated luminosity.

6. Tanaji summarized three beam-beam codes for Tevatron simulations: a)
BBSIM (his own) - 6D code, parallel, was used for wire compensition
studies, needs more manpower to continue work on Tev and LHC issues; b)
SLAC (A. Kabel) - reproduced experimentally observed SQRT(time)  and Q'
dependencies of 150 GeV pbar lifetime in 2003, now fully modified, also
needs manpower to produce more results for the TeV; c) LBL (Qiang) -
strong-strong parallel simulations code, gave predictions on 150 GeV and
LB lifetimes which strongly contradict observations.

7. Ron is on the way to automatic pbar tune stabilization at LB: a new
mult is built to move both H and V tunes simultaneously, mult was
found to be causing small (acceptable?) changes in proton tunes,
chromaticities and some 100 micron orbit distortions.


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