Minutes of the 11/08/02 Tev Dept Meeting


1. Welcome Vahid Ranjbar (newly hired RA in Tev Dept) and Frank Zimmermann
(visitor from CERN till Dec.17)!

2. Vladimir reviewed Tev progress since Sept.1,2002: average luminosity up
28%, record peak L is up 37% - mostly due to BLT work and better
coalescing in MI which resulted in larger number of pbars at LB. Number of
protons is down 3%, lifetimes of L, and p, pbars are about thesame as 2
mos ago. Major focus for Nov+Dec: prepare well for 3.5 week January'03
shutdown (starts 01/13/03), fix A1 line, avoid scallops in pbar emittances
after "initiate collisions", explore behefits of dampers, continue
studies. Predicted (record) peak luminosity in January'03 (37-44)e30.

3. Once again (Vladimir) we will have 3.5 weeks shutdown starting jan.13,
2003 - mostly to replace C0 Lamberstons (+ install Schottky detectors at
E17+replace TEL gun+some vacuum work+alignement)

4. Ray Stefanski, leader of the "Tev Alignement project", reviewed shutdown
work - mostly focused on C0 alignement after magnet replacement, there are
18 magnets candidates for re-alignement, Aimin Xiao helps ray to prepare
"beam sheets" (MAD work)

5. valery summarized recent BLT mtg: we have two system: McGinnis's
system will be used in future as head-tail monitor (+ provide info on
tunes, coupling, etc), digital receiver system (thousands of turns) to be
the main one for BLT as soon as it's ready.

6. Dean on the last week luminosity: it was far from stellar week
L=22...26, scallops (increased pbar emittances) hit the luminosity,
p-lifetime was really bad at 150 GeV (1.1-1.6 hrs). Intensity wise we were
at the same ball park as e.g. in store #1865 when L=33.6 but effective
emittance at that time was 20 pi while last week it was 25-28 pi. [Note:
over the weekend we lowered vertical tune, that eliminated scallops and we
got new L-record of 36.7 in #1953]

7. Morris Binkley & Co installed new counters near D49 target collimator
T:E0LABT, T:E0LTOT. Loss rate there is much larger than at the CDF
counters, so it's now easy to get enough counts to see loss
variationbunch-by-bunch, 53 MHz structure in the abort gaps and  in
between the bunches losses. Morris mentioned that since store #1914 losses
in the abort gap grow every store.

8. Todd commented on the earthquake-induced quench last Sun, Nov.3: signals
were seen well in low-beta tiltmeters and beam losses. The only orbit
motion was detected in the TEL vertical BPM of about 100 microns that
looks too small to be reason of the quench as regular 15 Hz orbit
oscillations are of about the same scale. So, it's not clear HOW
earthquake led to the beam loss. [ANL/APS beam was also lost at the same
time].

9. Todd: separator scan had shown that our separators are close to
optimum, no changes left.

10. XLZhang and Meqin presented results of the EOS WP scans: a) T55 page
tune changes were calibrated; b) available WP(tune) area for pbars is
about 0.006Hx0.003V and some 0.007Hx0.005V for protons; c) footprints have
strange shape, not always correlated with resonance lines; d) pbar
and proton losses are quite different for different bunches (e.g. some
bunches were not blown during the scan); e) it was found that proton
losses strongly anticorrelate with chromaticity (dN/dt goes up when C_v
or C_h were reduced) while pbar losses were not that sensitive (though
anticorrelate as well). Item e) is not what one would expect from general
theory.