- closed South Hall round 17:00.
- problems with beam injection so no beam until 21:00
- started optimisation of horizontal slits but made only minor changes from
settings found by Tancredi in previous shift (L/R -2/23)
- however, lead shielding makes significant improvement (~5 x less
background using the elastic_tof12-13 trigger and no gas in target)
- rates comparable to before narrow collimator tube installed
- also tried adding +/- 1 mm bumps vertically and horizontally at LL1 with
little change
- +/- 1 mr angle change at LL1 made injection virtually impossible
- nearing end of shift so decided to turn on BLAST toroid
- 2000 A background rates increased about a factor of 3 possibly a
retune of slits, bumps, and angles is needed
- 5000 A background rates reduced to values comparable to rates
without field but lifetime drops from 9 min to 6 min. -> retune ?
- give machine to machine group
- Jan reports that vacuum in target region is quite bad 10**-7 - 10**-8
Adam Degrush and Doug Hasell
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