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Archived Messages for EG1_RUN@cebaf.gov: Acceptance Tests at Oxford Instruments

Acceptance Tests at Oxford Instruments

Donald G. Crabb (dgc3q@erwin.phys.virginia.edu)
Fri, 27 Mar 1998 11:01:44 -0500

Dear Colleagues,
Today Marco and I accepted the magnet and refrigerator system
necessary for the eg1 run later this year. Both systems achieved
their specifications.
Briefly: the magnet has been ramped to 5.1T several times and
run in persistent mode. It was cycled between 5.1T and 4.845T
(simulating a deuteron TE measurement) for four hours, while work
was proceeding on the fridge. It was ramped from zero to full
field in 30 mins. The magnet protection circuit was proven during
a fortuitous power outage. The magnet was being ramped down and
did not quench.

Fridge: Tested with a small pumping system (estimated at 180
m**3/hr at the fridge top plate) and achieved 1.5K with the banjo
filled to 70% and the flow was measured at 20 l/m. The fridge was
used to fill the banjo three times and took 1 - 2 hrs to collect
LHe at the bottom (depending on the initial temperature). We put
in a 1W heat load using a real target stick with a heater
attached. This gave a flow of 36 lpm at 1.63K.
Stepper motor operation for moving the target up and down was
confirmed as was operaion with the needle valves.

After some minor modifications the system will leave the Oxford
factory on Monday (30th March) and be airfreighted to Boston. It
is estimated that it will take two weeks to arrive at TJNAF. An
Oxford rep. from the UK factory is scheduled to arrive on April
20th to start installation.

Regards,

Don Crabb & Marco Anghinolfi