Minutes from target meeting held November 25 2011 in 892-2-009

These minutes are available also from:

http://wwwcompass.cern.ch/compass/detector/target/Minutes/2011/

a) On Saturday 16:00 switch on the largest roots blower for empty target
cell thermal equilibrium calibration at 1.0 K. Finish the calibration on 
Monday 14:00. Start pumping out helium from the mixing chamber. At 14:30 stop
the helium-4 evaporator pumps and bypass the evaporator and the microwave 
cavity cooling line to the helium recovery. Pump out helium-3 from the vapor 
pressure thermometer. Ramp down the solenoid 15:00 and up again 15:40 for 
the magnet tests. The solenoid set to zero from Tuesday 15:00. The mixing 
chamber empty on Tuesday 00:00 and warmed 100 K by Friday morning. Magnet 
kept cold for electrical tests in superconducting state at nominal liquid 
helium level of 92 %.

b) While the mixing chamber was pumped empty at 1.5 K the trim coils were set
to zero and the NMR-signals were recorded from 16:00 on Monday to until
Tuesday morning. 

c) Start to measure the weight of the upstream sock of the unloaded ammonia
on Tuesday morning 9:00. No stable value reached by 17:00 due to sock partly
inside liquid nitrogen. Measure the weight of the two central cell socks
on Wednesday and Thursday.

d) Purge the helium-3 roots water circuit on Tuesday. Disconnect the 
temporary hoses for the water inlet and outlet. Leave the valves open to 
let any remaining water to slowly drip down. Purge the water from 
the helium-4 pumps on Wednesday and disconnect the water hoses. 

The pump room temperature from last week can be seen from

http://wwwcompass.cern.ch/compass/detector/target/run/checkhist.php

with command "WEEK PLOT TPR".

e) Change the liquid helium level in the 2000 l buffer dewar on the target
platform on Thursday 15:00 to 40 % and on Friday 7:00 to 20 %. The lower 
buffer dewar level allows faster emptying of the magnet for warming up.