Minutes from target meeting held May 11 2012 in 892-2-009

These minutes are available also from:

http://wwwcompass.cern.ch/compass/detector/target/Minutes/2012/

a) On Wednesday morning unsolder in the clean area the waveguide going to 
the downstream end of the microwave cavity. Remove the thermometers
and disconnect the helium-4 cooling pipes. Open the cavity downstream 
conical part. The mixing chamber touching the downstream microwave stopper 
with 2.9 mm gap on the top part. Measure the diameter of the downstream 
copper flange 448.94 horizontal, 448.96 vertical and 449.02 diagonal. Thus 
no deformation of the cavity in transverse plane. 

Open the upstream microwave stopper copper flange. The mixing chamber 
centering is ok. Remove the microwave stopper and the steel conical connection
piece from the dilution cryostat. The stoppers and the conical parts stored
into the office cup boards. The copper flanges are soft and are easily
damaged.   

b) Planning for the dilution cryostat and microwave tests were discussed.
The dilution cryostat can be leak tested with a helium leak detector after
replacing the mixing chamber with a steel flange. Possible longitudinal
deformation of the mixing chamber needs to be checked. The needle valves
can be tested separately with a flow meter.

c) Kaori: no spare amplifier blocks available on the market for the used
Q-meters. The company that had some stock was closed in 2009.

New EIO microwave generator tube bought from CPI Japan. The microwave
power supply needs to be send to Canada for testing with the new EIO tube.

d) Ideas and plans for the microwave cavity modifications were discussed.
The tensions and torques acting the cavity wall and the end window should be
estimated both for the case of the pressure difference between inside
and outside, and for the eddy currents due to rapid discharge of the magnet.