[Halla_parity] shifts cancelled until Friday Day

[Robert Michaels]

Dear Colleagues,

Shifts are cancelled until Friday Day.  The situation
may change between now and then leading to further
shift cancellations -- possibly until Monday.  We
will keep you apprised.

The PREX experiment has halted because of a large
vacuum leak which today was discovered to be at the
connection between the scattering chamber and the
collimator box.

Fixing this leak will require that the radiation
first subsides to an acceptable level, plus that
we have a good solution to prevent a leak from
happening again.

RADCON is in charge of monitoring the radiation
and following the DOE rules for determining when
it's safe to work.  The technical staff and physicists
are presently gathering information to deduce the
root cause of the leak and then coming up with 
a workable technical solution.

Please note: you will receive credit for any
shifts that were cancelled.

Sincerely
Robert Michaels
-------------------------------------------------------
Robert W. Michaels           http://www.jlab.org/~rom
Staff Scientist              phone (757) 269 7410
Thomas Jefferson National Accelerator Facility
12000 Jefferson Ave, Newport News, VA 23606 USA