Minutes of the October 7, 2005 Tevatron Dept Meeting

* News - Jim Volk will organize a series of "Shutdown Readiness" reviews for 
our projects in the upcoming long shutdown.  (There has been no official 
decision on the start and length of the shutdown, but we are assuming March 1 
and 14 weeks for planning purposes.)

* Letter of Recognition - Roger Dixon presented Alex Valishev with a letter
of recognition for his work on designing and helping implement the new 28
cm beta* lattice we now use for Tevatron HEP stores.  Congratulations, Alex,
and thank you for the good work!

* Store Summary (Bruce) - It was a mixed week.  Two shots (4416, 4425) were 
lost during the squeeze due to high losses.  Large orbit distortions were to 
blame for shot 4416, and orbit smoothing was done after that shot attempt,
although it's not clear why the orbit was so bad.  For shot 4425, a faulted
HV cable in the B17 horz separator system was mostly to blame.  Repairing the
cable required a tunnel access.  There were three successful stores - two of
them had the two best initial luminosities (4431 - 141 E30 and 
4433 - 140 E 30 cm^-2 s^-1).  Store 4431 also set the world best for peak
luminosity at hadron-hadron colliders.  (CERN's ISR set the previous mark of
140 E30 cm^-2 s^-1 in 1982.)  Operators needed to abort store 4433 prematurely
due to impending quench caused by a cryo insulating vacuum leak in A3.  Three
shifts were needed to identify the problem, make repairs, and complete the cool
down.  Additional work on orbits needs to be done to reduce pbar losses during
the squeeze.  D0 still sees elevated losses between low-beta and initiate
collisions, but they are not as severe as previously.

* Status of Orbit Stabilization Application (Jerry and Vahid) - Desired
features and operational details were ironed out during a meeting this week.
The application will run in the background (so-called "slot 7" program) and
will controlled via ACNET state devices.  Appropriate devices will be created
for controlling the step-cut, correction frequency, etc. The application will 
NOT restore dipole corrector settings after termination - the sequencer will 
handle that. Most features have already been implemented and can be tested 
this week.

* Improving HEP Lifetimes (Alex) - Alex had continued analyzing the reduced
lifetimes since we implemented the 28 cm beta* lattice.  He presented three
action items to attack the problems.  1) Center the CDF IP beta* waist 
longitudinally (a known problem).  2) Move the proton tunes above the 7/12
resonances for more reliable store-to-store reproducibility and reliability.
3) Reduce chromaticity, especially for pbars.  (The pbar chromaticities are
higher with the new lattice.)  We'll need octupoles for that, so we will push
for in-store studies to implement this scheme.

* "Poor Man's" Luminosity Leveling (Ron) - The term "luminosity leveling" was
heard in a recent AD 9 o'clock operations meeting, so Ron proposed one  
possible scheme to do it.  When we implemented the 28 cm beta* lattice
in the middle of HEP stores, we played a special ramp in the CAMAC cards to
do that, so he considered that as a "one-shot" leveling, since we understand
the mechanics of that scheme.  In prinicple, we could begin a store with say,
a 50 cm beta* lattice, and then ramp to the 28 cm beta* lattice later.  The toy
model can include scale factors for luminosity and lifetime changes 
before/after the ramp to smaller beta*, possible downtime for the experiments,
length of stores.  Note that this is just an academic study - neither of the 
experiments has asked us to implement leveling.  We would have much work to 
do...develop (at least) one larger beta* lattice with improved optics than we 
currently have in the squeeze, use study time to test the new lattices, make 
the special "one-shot" ramp scheme more operationally robust, etc.

* Studies/maintenance highlights for next week

   - Make the orbit stabilization application operational (Vahid)
   - Fix the CDF IP beta* waist (Alex, Jerry - need a proton-only store?)
   - Move the proton tunes > 7/12 for HEP (several people)
   - Additional crystal collimator scans (Dean, end-of-store)
   - Check chromatic beta-function near 1/2 integer (Alex, proton-only)
   - several additional proton-only studies if time permits...