Minutes of Tev Dept Meeting  07/12/02


1. Mike Church presented "Letter of Recognition" from John Marriner to
Bruce Hanna (for leadership of three recent harware improvement projects
and being Tev coordinator during after-shutdown recovery and meeting one
of the Run II milestones of luminosity 2e31). Congratulations!

2. Vladimir overviewed Tevatron status and 2 month progress. It'll be
posted on Tev Dept web page later. Summary: 10% increase in average peak L
since May (more pbars at low-beta); Tev changed a lot after May 21; we
have to fix newly appeared pbar losses during squeeze and p-losses on
ramp; previous expectations failed (we have 2.1e31 instead of expected
2.5); new expectation - we'll have 2.6-3.0e31 in September (10-15% more
p's and 15-20% more pbars  at low beta).

3. There was a meeting on C0 magnet replacement: it was decide to raplace
only lambersons with MI dipoles. Peter Grabincius will lead the project.
Bruce will help.

4. Peter Ivanov was introduced as a new Guest Scientist in the Tev Dept.
Initailly, he will work with Jerry Annala.

5. Bruce reported that there were 5 stores since last Fri, including
record L=2.13e31 with record 510e9 pbars at low beta. Lumi-Lifetime is
about 10 hours - about the same as in store 1337 May,20 when we had
previous record of 1.96e31. One store lost due to abort kicker prefire (no
obvious reason and fix).

6. Jim S. and CYTan have commissioned bunch-by-bunch longitudinal damper.
It works, it does not do any harm, has damping time 1-2 min, we hope it
will help to elimiate sigma_s blowup which again started to occure in
p-bunches early at 980 GeV.

7. Mike M. has measured tune and coupling drift at 150 GeV that latter is
as big as 0.025 (!) in 2 hrs. Drifts are repeatable within about 10%. The
data will be used for changing injection time-tables and drift
compensation.

8. Vladimir has presented some (3x12)x0 store data (analyzed by him, Slava
Danilov and Wolfram): a) loss on ramp depends on N_p - 14% for 200e9 and
8% for 50e9 (or on sigma_s which is larger for larger N_p); b) d
sigma_s/dt does not depend on N_p/bunch. As Tnaji mentioned, the last fact
contradicts to Paul SDA analysis ... but agrees well with previous 36x0
store in February.

9. Alvin used data in the store where RF station 2 tripped off to
calibrate CDF loss counters, separated losses due to luminosity, vacuum
and RF bucket leak. His estimate on the average Tev vacuum is 4e-10 Torr
that is factor of 3 better than previous estimate of Ron/Vladimir and
factor of 10 btyerer than Valery's estimate. Alvin also reported large
variation in the F11 vacuum pressure which contribute some 5-10% in the
CDF background. He aksed for one ACNET channel reporting TEv avg vacuum to
see effect of the beam heating.

10. Yuri and Bruce moved Lamberston to see how beam position at F0 affects
150 GeV lifetime (Last week they found it's 2.5 times better on pbar helix
than on the proton one - 5 vs 2 hrs). Vertical centering (5 mm
bump) allowed them to get lifetime on p-helix to about 4.5 hrs.

11. TEL shift was reduced t 2 hrs (reports Vladimir), 70-100 hrs lifetime
was obtained with dQ=0.0028, but when e-position changes were made to
increase it to 0.0032, the lifetime dropped significantly to 12 hrs
(why?=puzzle).

12. Tanaji presented pbar only store tune measurements - another puzzle:
vert tunes reported by two instruments (Schottky and Tan's Q-meter)
disagree a lot (0.01). There was no comparison made with p-tunes on pbar
helix (topic to study in the future).