Minutes of the Feb 11, 2005 Tevatron Dept Meeting

1. Dept news (Vladimir): BTeV is cancelled, probably no C0 work during
next shutdown, the shutdown date and duration not set yet.

2. Ron Moore on operations: 4 stores lumi from 42 to 78e30, all the time
shoot from reduced stack/stash beacuse of either quench before or problems
in the injection chain; 2 quenches - one in squezee seq 18-19
(unexplained), another in #3969 due to human error (RF reference for 
longitudinal damper unplugged --> bunchlength growth, 65e9 in DC beam -->
losses at E --> abort...quench at A1 but NO LB quench! 
Need SBD profiles to be saved on every
abort); octupoles are introduced at 150 GeV and in the latest 4 stores
they reduced pbar losses by factor of 2 or so, and proton loses at 150 GeV
helix by factor of 1.3 or so; those 2% of pbars saved at 150 are later
shaved on the ramp; there is 1% sudden loss of pbar at seq 24 of the
squeeze exactly where Qy=-0.007 tune excursion occurs (need an extra
sequence point to fix it; or smth else like temporary increase of
separator voltages).

3. Jim Volk and others on short 4 shift shutdown after MI PSs accident:
F17 kicker replaced, A49 separator leak fixed, crystal collimator
repaired, F0 leak is being fixed now; RF cavity water heaters and A17 vert
Schottky were not fixed due to various reasons.

4. Yuri explored effects of crossing angles on luminosity at
the end of store and saw 1-2% changes at both CDF and D0. He also
explained in detail how he, Jerry and Peter introduced octupoles in
operation; now chromaticities are H/V=4/4 for protons and 0.5/(3-4) for
pbars; he suggests to lower vert Cv for pbars by 3 units.

5. Peter Ivanov compared 150 GeV lifetimes in stores without and with
octupoles: pbar lifetime for the same emittance bunches improved by factor
of 9; now with octupoles even AA pbars with Emm=11pi live twice better (36
hrs) than 5 pi pbars from RR without octupoles; proton lifetime with
all pbars loaded improved by factor of 3 (store 3968 vs 3952); he
suggests that longitudinal shaving is affecting proton lifetime.

6. Vladimir added that in (a typical) store 3972 proton loss rate at 150
was proportional to a number of pbars loaded; that's a clear sign of beam
beam effects. Yuri suggested to move hor tune off 12th order resonance
(from 0.583 to 0.586) to reduce the p-loss.

7. Aimin looked into difference between antiprotons in the Tevatron loaded
from RR and from RR (16 stores after shutdown): RR-Pbars have better
efficiency to LB (98% to 92%)  due to probably smaller emittance; they
have better intensity lifetime at LB but slightly worse luminosity
lifetime (not reasonable exlanation found);  bunch length is longer, too.

8. Vladimir added that in store #3972 average effective emittance from
luminosity (Na*Np/Lumi[i]) is 10% smaller for pbar bunches from RR; but
according to AA/RR guys for the same stack or stash size, the emittances
in AA and RR are about the same.

9. Jim Steimel informed on staus of new BPMS: A3 BPM checks are ~complete;
TCLK interrupts fixed by reducing closed orbit acquisition rate from 500Hz
to 100Hz; W68 page allows now to get TBT ASCII data; B3 house BPM system
was installed in 1.75 hours.

10. Valery reported that his lattice measurements show no big
difference in beta-functions bteween Feb'05 and April'04. Vladimir
mentioned that E17 hor-beta function changed by +25% according to tune
modulation-by-quad method (too much to be explained by the inaccuracy
of the differential orbit method).


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