Minutes of the July 29, 2005 Tevatron Dept Mtg

* News (Ron) - The start and duration of the "Fall 05" shutdown won't be
decided until mid-August.  It is possible the shutdown may not happen until
some time in 2006.  Ron will be away next week, so Jerry will be Acting Dept
Head.  AD Headquarters wants to know what equipment we expect to purchase 
in the remainder of this fiscal year - send your list to Jerry by 8/2.

* Weekly Summary (Bruce) - 7 stores were attempted this week.  Initial
luminosities ranged from 56 to 115 E30 cm^-2 s^-1.  One (4298) ended in a 
quench during the squeeze (LBSEQ 7).  It was a fast loss, consistent
with a separator spark, but no sparks were recorded.  The B17H and C17V seps
were conditioned @ 145 kV anyway after the event.  Three stores were ended
intentionally.  Store 4301 ended with a pbar abort kicker (AAK5) prefire.
That tube last prefired on 2/28/2003.  Store 4304 was terminated after only
2.7 hours by a Main Injector studier who mistakenly pushed the Tevatron abort
button instead of the Main Injector abort reset button.  Store 4308 is in
progress.  The horizontal proton tune was lowered 0.001 to help improve
lifetime with high brightness pbars from the Recycler.  Occasional proton
longitudinal instabilites have reappeared, so we have reinstituted lowering
the longitudinal damper gain during HEP stores.  Pbar tune stabilization is
now operational.  Bruce looked at the A49 RGA before and after a recent quench
at A4.  Surprisingly, he saw increased He after the quench, as well as 
increased in H and Ar.  He has not obtained the temperature data yet.

* Pbar Tune Stabilization (Ron) - The OAC (Open Access Client) TEVATF is now
operational.  The goal is to keep the pbar tunes above the 7/12 resonance as
the beam-beam tune shift decreases over a store.  The OAC monitors the pbar 
tunes from the 1.7 GHz Schottky system and causes an ACNET device to alarm when
the pbar tunes should be increased.  MCR operators then use a dedicated tune
mult to raise the horz and vert pbar tunes simulataneously (in steps of 0.001).
Horz chromaticity increases with those tune changes, so the mult will be
modified to compensate the chromaticity changes.  The proton tunes could be
monitored and adjusted in a similar manner to help proton lifetimes during
stores with high brightness pbars.

* 28 cm beta* Status (Alex) - The model is well-described by both turn-by-turn
and differential orbit measurements - differences between the two methods are
on the order of 1-2%.  The model still shows much improved beta-beating in
the arcs, as compared to the current 35 cm lattice, after additional tweaks.
The model indicates horz/vert beta* 29.9/28.0 cm @ CDF and 28.1/27.4 cm @ D0.
The waists are offset ~5cm or so; Alex will make new alpha bumps for the 28 cm
lattice.  Alex showed results of beam-beam simulations; beam-beam effects are
no worse than for the 35 cm.  Specifically, the beam-beam contribution to 
lifetimes and backgrounds should not change.  Yuri noted that based on 
initial results of TBT analysis from data on the helix, the beta* on the proton
helix are slightly smaller than for the central orbit.  Another round
of proton-only studies are needed before trying the new optics at the end of
an HEP store.


* Studies for next week -

   * Cont'd 28 cm beta* - helix, feeddown, maybe even end-of-store?

   * Tuning TEL for cleaning DC beam during injection

   * Commissioning coupling measurements with C100

   * Crystal collimator commissioning

   * Test Mode 0 longitudinal damper (needs hardware check before beam study)