Minutes of the Jun 8, 2007 Tevatron Dept Meeting

https://indico.fnal.gov/conferenceDisplay.py?confId=916

* News (Ron) - Welcome to Debbie Ziomek as our new administrative assistant!
Andreas Jansson, Jim Steimel, Elmie Peoples and Ken Koch are now part of the
new Accelerator Physics Center, but they will continue to contribute to
Tevatron operations and support.

* Weekly Operations Summary (Dan Bollinger) - The Tevatron delivered 38 pb^-1
to each CDF and D0 over the past week, and there was even one 7 day period
in which 45 pb^-1 was delivered!  We have surpassed 1 fb^-1 delivered for 
FY07.  There have been 6 stores with initial lumi between 138 and 257 ub^-1/s.
All HEP stores were terminated intentionally.  One shot was lost during the 
squeeze (fast quench @ C2); the quench seemed consistent with the beam valve 
at C2 closing onto the beam, but there was no direct evidence of that, and 
attempts to reproduce the problem failed.  The Recycler mysteriously lost its 
pbar stash soon after the lost Tev shot, so the next store had few available 
pbars.  One of the beam valves around the A49 separators has a leaky actuator;
mechanical techs added additional compressors to keep the valve open while 
they wait for an opportunity to fix it.  The new sextupole circuits were tried
during pbar injections on 1 shot and implemented at low-beta for 1 HEP store;
we need additional stores to evaluate their performance.  Introducing a B0 
vertical angle bump @ LBSEQ 7 seems to decrease the CDF losses; the bump will 
be extended to other parts of the squeeze.

* Shutdown Tasks (Jim Volk) - Jim showed a draft timeline of the Tevatron
shutdown tasks.  We hope to "lock in" all the work requests soon.  Four houses
will be warmed up to fix known cold leaks or unroll magnets.  The usual 
low-beta quad alignment will be done, and we hope to replace stands on ~40 
magnets.

* New Sextupole Commissioning (Alex Valishev) - A new mult to turn on the 
second order chromaticity sextupoles at 150 (while keeping the tunes and 
coupling ~fixed) was exercised. This mult was then used to try roll-in the
new sextupoles during pbar injections of one store; reverse injection tune-up
was done without those sextupoles on, so the first pbar transfer had larger
than normal emittance dilution caused by poor closure.  There was no visible
impact on the proton lifetime (good or bad) because the pbar intensity was
low and the injected proton bunches had good delta_p/p.  Store 5480 was the
first store with the new sextupoles in use at low-beta; all of the corrections
(tunes, coupling, separators) needed during an "in-store" study last week were
implemented, too.  Overall, it went well, but the pbar vertical tune landed
high causing some emittance blow-up, and the proton vertical tune landed low
causing reduced lifetime.  Additional tweaks will be made for the next stores.

* IPM Status (Andreas Jansson) - The vertical IPM shows evidence of quadrupole
oscillations during proton injections.  Andreas will begin working on studies
to improve the lattice match between the P1 line and the Tevatron.  The horz
IPM, which has the full complement of 80 channels now, has some timing
synchronization problems - Andreas suspects a problem in the firmware on one
of the upstairs boards.  There is also some "structure" in the background,
presumably from electrical noise, that would affect the measured bunch
profiles.

* Plan for Next Week

   - Complete implementation of second order chromaticity sextupoles.
     (Including proton-only and pbar-only (!) for collision helix closure)
   - Continue work on reducing CDF losses during the squeeze.
   - TEL-1 studies (Seva, during HEP stores)
   - IPM studies (Andreas, shot-setup and/or proton-only)
   - Chromaticity Tracker (Tan, proton-only)
   - Try E48 bumper as abort gap cleaner (Steimel, Bruce, Elmie, proton-only)