Minutes of the June 20, 2008 Tevatron Dept Meeting

http://indico.fnal.gov/conferenceDisplay.py?confId=1888

* Weekly Operations Summary (Xiaolong Zhang) - The Tevatron delivered 50 pb^-1
to the experiments this week.  There have been 8 HEP stores during the week
with initial luminosities between 191 and 286 ub^-1/s.  Store 6221 ended in a
quench during a thunderstorm; a lightning strike damaged a number of electronic
components.  Store 6228 quenched during another attempt to separate the beams
for CDF in an end-of-store study; more analysis is needed before attempting
again.  Store 6232 aborted cleanly when a small power supply in A2 failed
causing the main bus supply to think there it had an overcurrent condition and
resulted in a ramp dump.  Also in store 6232, the B11 vert separator sparked
a caused a ~40% drop in luminosity.  The B48 separator polarity switch is 
locked in single polarity due to a failure - no real impact on operations.
Xiaolong noted the FBI pbar intensity has been reporting more beam loss on
the ramp recently, but SBD does not show it - Instrumentation will investigate.
The low-beta QPM fast abort parameters were adjusted.  The D0 BPM network
was changed to 100 Mb operation.  A new version of orbit stabilization was
released (prevent sending out orbit changes after an aborted store.)

* IPM Status (Andreas Jansson) - The IPMs are now state-driven, similar to the
flying wires.  They are still fighting occasional data synchronization problems
that need to be solved for fully automatic data-taking.  After moving the 
teststand to FCC (with *real* beam-sync signals), they saw missing markers that
the front-end and buffer boards handle differently and causing errors.  They
also see unexplained PCI accesses to the buffer boards during data acquistions.
They hope to test new firmware some of the modifications in the horz IPM this
week.

* Pbar Collimator Study (Dean Still) - Although their standard pbar halo
counters show no problems, CDF has noticed higher rates of "missing Et"
background events from the incoming pbar direction of their detector.  They
have other halo counters that show rates much higher for pbar than protons.
Dean has found that a couple of the pbar collimators are occasionally stopping
short of the beam.  In an end-of-store study, Dean tried moving various
pbar collimators to investigate how to reduce the rates in the other counters.
He was able to reduce those rates by a factor of 6, but we don't yet know if
the background event rate at CDF was affected.  Dean has made some changes
to pbar scraping.

* Plan for Next Week (All)

   - Luminosity, luminosity, luminosity
   - P1 line matching (Alex, Jerry - proton only)
   - Bumper as Abort Gap Cleaner (Bruce, Steimel - proton only)
   - Chromaticity Tracker (Tan - proton only)
   - Test new 460 firmware (Jerry, controls - dry squeeze)
   - New BLM electronics (Dean, Marv - between stores)
   - TEL 2 parasitic studies (Seva, during HEP)