---------- Forwarded message ----------
Date: Sun, 07 Sep 1997 11:47:26 -0400
From: "Arne P. Freyberger" <freyberg@claspc1.cebaf.gov>
To: clas_photon@CEBAF.GOV
Subject: good news and bad news
Dear Clas Photon Collaborators:
I happy to inform you that the cause of the low tagging efficiency
has been found however I am not pleased that the problem was due to my
incompetence. I apologize for up-front for all the effort that appears
to have been for naught and I am at your service to try to recover as
much as possible of the past weeks run.
The low tagging efficiency during the photon runs and possibly poor
beam quality during the June electron run was due to 4 aluminum
alignment knobs on the alignment laser. These knobs were positioned
directly in the beam. The knobs are roughly 1cm in diameter and
made of Aluminum. The knobs should have been rotated out of the beam
but when the vacuum box was opened today it was immediate apparent
that the knobs were directly on beamline.
The laser has been removed.
Again, I apologize....let me know if I can be of any more help.
Arne
--
Arne Freyberger
JLAB (Mail Stop 12H) Phone: (757) 269-6268
12000 Jefferson Avenue Pager: (757) 680-8884 freyberg@cebaf.gov
Newport News, VA 23606 Phax: (757) 269-5800 http://www.cebaf.gov/~freyberg