Minutes of the April 2, 2010 Tevatron Dept. Meeting

http://indico.fnal.gov/conferenceDisplay.py?confId=3259

* News - The Tevatron delivered a monthly record 272.7 pb^-1 to CDF and D0
in March 2010 (previous best 254.1 in Dec 08).  Nine of the top ten initial
luminosities occurred in March.  Congratulations!

* Weekly Operations Summary (Jerry Annala) - The Tevatron delivered 70.8 pb^-1
to the experiments over the past 7 days.  There have been 9 HEP stores with
initial luminosity between 252 and 361 ub^-1/s; no stores were lost
prematurely.  We still have longitudinal pbar instabilities early in stores,
but new instrumentation was added to each RF cavity this week; hopefully those
higher-order mode power meters will shed some light on the situation.  Both
proton and pbar halo rates have been high at start of HEP this week; looks like
tunes are not quite optimal early on.  Orbit changes across B0 has helped 
reduce proton beam loss early in the squeeze.  Planning for a ~12 hour shutdown
in 2 weeks to address the Feeder 46a fault as well as long accesses needed for
CDF and D0.

* Emittances between MI and Tevatron (Jerry Annala) - Jerry has been comparing
MI and Tevatron flying wire emittances for various beam scenarios (forward &
reverse injection line tune-up, protons & pbars for HEP shots).  It's hard to
conclude if there is a real blow-up between MI & Tevatron.  Simple scaling of
the emittances or slight changes in parameters (beta function, dispersion)
can make the emittances consistent.  The MI wires may be flying late upon 
reentry during our reverse injection tune-up the for A1 line.

* TEL-2 Beam-Beam Compensation Studies (Alex Valishev, Giulio Stancari,
Christoph Montag) - Recent progress includes demonstrating good alignment
between the (gaussian) e-beam and antiproton bunches during an HEP store; 
while scanning the e-beam horizontally and vertically, they observed expected
pattern of changing halo from the single bunch the e-beam was on.  During a 
pbar-only store, they observed the expected tune shift and spread as the 
electron current was varied.  During another colliding beam store, they 
observed the expected coherent modes and tune shift with and without the 
e-beam acting on a pair of antiproton bunches.  Plans include additional
analysis on gathered data and a couple of "special" colliding beam stores,
perhaps 3x3, where they could scan the e-beam on individual proton and pbar
bunches, to study the compensation of head-on beam-beam effects.

* Plan for Next Week (All)

   - Luminosity - deliver lots of it.
   - Chromaticity Study (Tan, proton-only)
   - Tune Mult Calibration (Ron, EOS)
   - TEL-2 abort gap cleaning (Alex, EOS)
   - Pbar BPM TBT test (controls, etc., shot-setup)
   - Aperture scans at CDF and D0 (proton-only)