After some initial tune up it was immediately clear that the TAC was
seeing 85-90% of the tagged photons. Consistent with the losses due
to 35meters of air. We were able to take several runs with different
configurations and all are consistent with a tagging efficiency above
95% once you correct for the losses.
The collimator was also installed and the efficiency drop to 60%,
obviously the beam will have to be brought to the center of the
collimator. I also hope to get a chance in the comming down times to
realign the collimator since the platform was inadvertly moved by the
survey crew.
We also made first use of the 1nA BPM cavitity installed on
Monday/Tuesday of this week. Once the system is fully operational we
will know the position (to within 100microns) AND ANGLE of the beam
at the radiator. This will aid in our alignment.
Last night success was the result of the fact that ALL systems were
working and although many of you could not be present for this shift,
it is obvious that ALL the hard work and previous shifts paid off in
the end.
Onward to March/April!!
Thanks everyone for your efforts!!!!
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