The schedule now stands as follows:
July 18-21 Tagger commissioning at 1.6 GeV
July 25-28 Tagger commissioning at 4.0 GeV
August 1-4 Tagger commissioning at 4.0 GeV
August 8-12 Photofission at 4.0 GeV
August 14-19 Photofission at 1.6 GeV
August 20-21 Photofission contingency
In view of past performance of the accelerator, I'm afraid this still has
to viewed as somewhat tentative, making it hard to plan, especially for
those of you who are far away. Still, it's the best guess we have, and
for now we need to treat this schedule seriously.
There was some sparking damage to some of the PPAD cathode foils during
the last run, and new ones are being fabricated so that we have plenty of
spares. Our best guess is that this was caused by periods of intense
radiation when the accelerator was run in pulsed mode. We won't put them
in the beamline again until AFTER the beam is tuned satisfactorily.
It turns out also that no PPAD data was saved. Apparently, no one thought
to read the disk until after the run was over, and before this could
happen the disk crashed and all was lost. Henceforward we'll read the
data disk periodically, at frequent intervals. All the same, we are
confident that all is well, from the analog spectra and counting rates
that we acquired for selected PPADs.
We'll have a meeting at JLab on Friday, July 25, at 2 pm (room TBA). I
hope that most of you who plan to participate in the data runs will be
there. Thanks very much, Barry
Barry L. Berman
Professor and Chair
Department of Physics
The George Washington University
Corcoran Hall, Suite 208
725 21st Street NW
Washington, DC 20052
Telephone: (202) 994-7192
Secretary: (202) 994-6276
Fax: (202) 994-3001
>>> Please note: My new E-mail address is berman@gwis2.circ.gwu.edu <<<