X.L. Zhang, F. Zimmermann

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EOS- lifetime and losses vs chromaticity11/26/200
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X.L. Zhang, F. Zimmermann
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end-of-store study on 11/26 reduce CH,V by 10
units in steps of -1
no effect on intensity or loss, some increase in
H Schottky power at 10 sudden instability and
beam loss quenched the Tevatron
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• some related informations
• quench appeared to have been caused by p-bars
• (signature of pbar quench at F48, by Dean et
  al.)
• on November 4 Xiaolong had scanned both Ch and
  Cv
• (independently) by 24 and 20 units without
  problems
• but a quench occurred at DCv -21
• in p-bar removal study on November 17, proton
• chromaticities were measured as Ch13, Cv16
• (i.e., lower in H)
• according to Tanajis calculation the
  0-amplitude
• chromaticities of p-bars are lower by 10 and
  1 units
• compared with protons (at 3s the differences
  are 6 and
• -3)

if we trust these numbers the nominal pbar
chromat. is Ch3 only, which was dropped to 7
in the course of the study - no wonder the beam
became unstable!
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absolute changes were certainly larger on
November 4, but
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perhaps we cannot deduce from the two successful
pink curves that the brown one should be stable
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circumstantial observation that the sextupole
feeddowns (S5F1A-S5D3A) were 50 different on
the two occasions, namely Nov 4 4.2
- 4.3 Nov 17/26 6.7
why were they different, and does this matter
for the p-bar stability?