Subject: Minutes of the Tev Dept mtg , June 13
Date: Fri, 14 Jun 2002 18:17:39 -0500 (CDT)
From: Vladimir Shiltsev <shiltsev@fnal.gov>
To: tevatron <alexahin@fnal.gov>, annala@fnal.gov, balbekov@fnal.gov,
     bhanna@fnal.gov, bollinger@fnal.gov, church@fnal.gov, cytan@fnal.gov,
     drozhdin@fnal.gov, erdelyi@fnal.gov, gena@fnal.gov, jwalton@fnal.gov,
     koch@fnal.gov, martens@fnal.gov, mccormac@fnal.gov, meiqin@fnal.gov,
     mokhov@fnal.gov, P.M.Ivanov@inp.nsk.su, ronmoore@fnal.gov,
     shiltsev@popgtw.fnal.gov, slaughte@fnal.gov,
     steimel@fnal.gov, still@fnal.gov, stupakov@slac.stanford.edu,
     syphers@fnal.gov, tjohnson@fnal.gov, tsen@fnal.gov, val@fnal.gov,
     xiaoam@fnal.gov, yunhai@slac.stanford.edu, zhangxl@fnal.gov
CC: tevcc <alvin@fnal.gov>, cheung@fnal.gov, emclark@fnal.gov, harms@fnal.gov,
     mont@fnal.gov, stephen@fnal.gov

1. CY Tan: there was a meeting on longitudinal instability (dancing
bunches) where Valery Lebedev and Valery Balbekov presented an idea of an
iductive impedance as possible reason for that. VB estimates Z/n to be
seme 2 Ohm. A non-physical delay is part of the model and has to
beremoved. John Reid is finishing installation of passive dampers of 153
MHz HOMs in the TEV cavities.

2. Bruce reported that all the work planned for the shutdown is complete
(only exception - baking C49 separator, but the vacuum is not bad there).
There are indications of cold air leak in 2 of 7 cryohouses warmed during
this shutdown. F11 vacuum improved to 1e-9 Torr (at ion pump). 4 larger
aperture BPMs and 2 striplines are installed at F0 and baked.
Problematic torlon pieces (current leads) are replaced. Surveyors observed
significant roll (>4mrad) in a number of dipoles at E2 and B1. D0 vacuum
was measured with ion pumps ON /OFF --> should be enough to estimate
for outgasing rate.

3. Mike Martens has finnished processing tune drift data:
after 40-60 min at 150 GeV vertical drift is +0.015 and horizontal -0.007.
Time dependence is close to measured behavior of b2 components in SC
dipoles. We did not observe tuneshifts of that scale in Run I. His
analysis excludes that the shift is due to orbit in SD SF sextupoles
(more 1 mm systematic same-polarity offsets are reqired). A
possible explanation is varying sextupole strength in Tev dipoles with
systematic orbit offsets.

4. (after the meeting Alvin pointed out that F11 vacuum rise in the last 3
stores before the shutdown - with old "bad" ferrite - was much smaller-->
indication of a threshold effect that strongly depends on proton intensity
and bunch length.)