Minutes of the Mar 13, 2009 Tevatron Dept Meeting

http://indico.fnal.gov/conferenceDisplay.py?confId=2446

* News (Ron) - Ryoichi Miyamoto won the APS Award for Outstanding Doctoral
Thesis Research in Beam Physics (Tevatron AC Dipole) - congratulations!

* Weekly Operations Summary (Jerry Annala) - The Tevatron delivered 47.3 pb^-1
to the experiments over the past 7 days.  There have been 7 stores with initial
luminosities between 165 and 311 ub^-1/s.  All were terminated intentionally
except store 6891 which ended this morning when there was a power glitch.
Two more shots were lost during the squeeze when the C4Q3 low-beta quad
quenched.  There has been a lot of effort spent investigating these quenches,
but no smoking gun has been identified.  Protons are being lost at the time
(beam-beam effects), but there is no indication of increased loss at those 
quads; indeed we survive much higher losses at nearby locations earlier in the
squeeze.  Aperture scans show no restriction.  Vertical orbit angle changes 
around the time may be contributing, so some bumps have been implemented.  The
pbar sync light mirror that starts moving in during the squeeze has been 
effectively ruled out as the cause.  Cryo lowered the temperature of the string
a small amount (0.1K at the cryo feedcan).  As a sanity check, we stopped 
testing the insertion of the E01 horz collimator during the squeeze; it should
have been far from the beam.  Some minor tuning has been done, but there were 
no obvious problems to correct.  The last 6 stores have been successful, so 
we're cautiously optimistic for now.

* Losses in the Squeeze (Alex Valishev) - Alex summarized all this things we've
considered during our investigation into the lost stores.  (Many things 
mentioned above.)  The incoming beam quality is essentially the same since
Dec 08; the proton bunch lengths are just slightly longer.  There is some 
evidence of longitudianl bunch shaving just prior to the quench, but the beam
loss during the helix transition earlier in the squeeze has been improved, so 
perhaps we're just losing off-momentum beam later than previously.  Alex
also measure the lattice at LBSEQ 22 (prior to the quench), but all looks OK
there.

* Planning for Long Shutdown (Jim Volk) - Jim summarized the known work
requests, assuming a 10 week shutdown starting June 15.  We can likely warm
up 4 houses to fix cold leaks.  Also on the docket: the usual magnet roll 
measurements, low-beta as-founds, ~50-60 magnet unrolls, ~several magnet stand 
replancements, hydrostatic level work, move horz crystal collimator and insert
vert crystal colliamtor, various maintenance.

* Plan for Next Week (All)

   - Recover the Tevatron after this morning's glitch.
   - Deliver luminosity to CDF and D0.
   - Crystal Collimator (Dean et al., end/start of HEP)
   - Tune Mult Calibration (Ron, 2 hr end of HEP)
   - Test E01 collimatior in squeeze (Jerry, proton-only and HEP shot)
   - Bumper Magner as Abort Gap Cleaner (Bruce et al., proton-only)
   - Chromaticity Tracker (Tan, proton-only)