Minutes of the Aug 1, 2008 Tevatron Dept Meeting

http://indico.fnal.gov/conferenceDisplay.py?confId=1958

* News (Ron) - Planning continues for a 5-day shutdown possibly for early
October; the length is driven by the time needed for ComEd to replace an SF6 
switch on the electrical circuit feeding the Master Substation.  D0 has
surpassed 4 fb^-1 *recorded* luminosity; come join them for an informal
celebration today at the Users' Center at 5 pm.

* Weekly Operations Summary (Ron for Jerry) - The Tevatron delivered 52.9 pb^-1
to the experiments this week.  The total integrated luminosity for July was
195 pb^-1, the 3rd best ever.  There have been 7 HEP stores with initial
luminosities between 181 and 303 ub^-1/s.  Store 6324 set a new integrated
luminosity record of 11217 nb^-1; it was kept for > 40 hrs due to a Transport
access to repair a magnet that prevented any beam delivery past Booster.
All stores have been terminated intentionally.  All BLM houses have been 
converted to use the new electronics; many thanks to all involved in that
project.  BLM aborts during shot-setup were traced to a bug in an OAC that
led to the incorrect (lower) BLM thresholds being used; a fix was implemented.
There has been a rash of ACNET setting timeouts that have prevented some orbit
corrections and caused "incomplete" tune changes during shot-setup; controls
is investigating.  The E1 sump still needs to be repaired/replaced.

* New BLM Status (Dean Still) - Dean summarized the current situation.  All
BLMs are now using the new readout electronics.  They are unmasked at 150 GeV
just like we used the old system, but we will proceed on learning how to 
enable and set threshholds for *individual* BLMs at other times.  There are 
still some bugs to be worked out and additional features to exploit.

* Electron Cloud Study (Xiaolong Zhang) - Xiaolong reported that they were
able to reproduce earlier results where vacuum at A0 and C0 jumped > 3 orders
of magnitude with 30 uncoalesced bunches > 40 E9/bunch.  They were able to
inject 50 bunches, but the MI damper gain needed to be adjusted; they hope to
up to 80 uncoalesced bunches in a future study.  They saw ~4 pi/hr emittance
growth, much smaller than a previous study, but higher chromaticity may have
caused a suppression; they would like to measure emittance growth vs
chromaticity in a future study.  Moving the tunes close to resonances did not 
seem to change the emittance growth rate.

* Plan for next week

   - Luminosity, luminosity, luminosity.
   - Correct orbits during the squeeze.
   - b2 Drift Compenstation (Viktoriya, Ron, Jerry, 2 hr proton-only)
   - gap cleaning with bumper (Bruce, Jim, Elmie, proton-only)
   - ecloud studies (Xiaolong, Bruce, Vladimir, proton-only)