Minutes of the TeV Dept meeting, April 19, 2002

1) Vladimir announced shutdown plan: 2 weeks starting may 15 (or possibly,
June 1), and 5 weeks later this year (October?)

2) Todd informed about measures to make abort safer for the CDF in case
kicker trigger AA marker disappears. Seems that the hardware exists and in
some 2 weeks a proper scheme will be implemented.

3) Jean briefly overviewed CDF/D0 lumi discrepancy meeting. The work is
just started. D0 is probably overestimate its Lumi by 2-4%.

4) Jerry reported that the only two stores last week were not better not
much worse than others (L=12.3 and 10.8 e30). New proton intensity record
7.053e12. CDF losses suffered from F11 vacuum.

5) Harry Cheoung calibrated sensitivity of the SyncLite detector area and
observed number of "burnt" spots. Beam image moved to a better, fresh
spot.

6) Mike Martens reported much better pbar lifetime for smaller pbar
emittance (1hr for 32 pi, 4 hours for 9-12 pi). New 150 GeV helix is not
worse than the old one - so we stay with it and will try to improve pbar
lifetime. Tune measurements with Tan's tune-meter make more sense now.
Losses at the beginning of the ramp are huge for large emittance pbar
bunches. Mike noticed significant tune wobbling around 168 GeV - new
break-point to be introduced into the C49 next week and we'll try to
correct that.

7) Yuri and Jerry did study effect of octupoles on protons at 150 GeV. The
goal was to reduce chromaticity (expectations are that
p-lifetime will increase) by introduction of tune spread by octupoles. They
were able to reduce chromaticities down to 4 units (usually about 8) for
high intensity 36-bunch p-beam.

8) Bruce was looking into the TeV vacuum and observed terrible outgassing
of the ferrite at F11 sector when the beam is ON for more than 1 hour.
Seems that that phenomenon was there for a while.
F11 pressure rises from fewe-8 to 2e-6 Torr. The pipe is now baked for 17
hours at 110 C.

9) Vladimir correlated the F11 pressure rise with the bump in the CDF
losses few hours after beginning of many recent stores. On base of known
F11 pressure change he estimated average equivalent TeV vacuum to be some
2.4e-9 Torr [equivalent means assuming the same T, gas content as in F11].
The number is 15 times smaller last week estimates made by Valery on base
of 150 GeV emittance growth measurement.

10) XL Zhang measured A0 Horizontal orbit motion at low frequencies and
found many peaks including nx4.6 Hz (at n=1, amplitude was some 3-4
microns). Orbit motion at synchrotron frequency (32-35 Hz) can be
explained by 50 mrad=3 deg coherent phase oscillations - that must be
confirmed by beam phase measurement system (Tan/Steimel).