[BLAST_SHIFTS] Run plan for tonight

From: Karen Dow (kdow@mit.edu)
Date: Tue Aug 24 2004 - 14:27:47 EDT


        Solenoids were full around 2pm after clearing an ice blockage. This means
the solenoids won't be at operating current until around 5pm, and therefore
no beam until 5pm.

        Repairs to the BLAST switchgear have been completed. ABS RF generator is
replaced. Turbo pump power supplies are now chilling.

        Nozzle and cryos have been regenerated. After the nozzle is cold, Genya
will check the alignment, and then the BLAST power supply will be run up.

        Once beam is back, Jan and/or Fuhua will work on the beam tune and try to
decrease the wire chamber scaler rates, and make the right and left WC
rates about the same. The overall WC scaler rate impacts our dead time,
and the high right rates may be causing the roll-off at large drift
distances in the right WC timing spectra.

        When the beam tuning is done, we will resume data-taking on polarized
deuterium. Chi has found indications that the spin angle is pointing more
forward now than it should, since about 2 days ago. We can't confirm that
with the Hall probe inside the chamber (broken) or with power supply V and
I (they appear stable for the past week). I think we have to continue
running on the assumption that the spin angle is 32 degrees and Chi is
battling statistics, and work out a plan to replace the Hall probe (which
involves opening the target chamber).

                                        Karen



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