Minutes from target meeting held November 14 2014 in 926-1-039 

These minutes are available also from:

http://wwwcompass.cern.ch/compass/detector/target/Minutes/2014/

a) Try to get reading from all of the resistive thermometers in the still 
(helium-3 evaporator) and in the heat horizontal heat exchangers. TDR6, TDR7,
TPR7 show reasonable values. TTH9 inside the target holder vacuum space
has some bias on the reading. The TDR1 and TDR2 in the heat exchangers
are probably 1 kohm RuO chip resistors (RCWP-575 Dale). 

b) Check the voltage reading from the horizontal screen flow controller
FM50 and vertical screen controller FM51. For FM50 one Volt corresponds
to 2 SLPM and for FM51 one Volt is 0.2 SLPM. For the cavity flow meter
one Volt is 10 SLPM.

c) On Wednesday start to condense helium-4 to mixing chamber at 9:20 and 
stop condensation at 15:00. The flow in the helium-3 circuit stays high,
which is not normal. One possible explanation is a partial blockage due to
nitrogen ice inside the vertical heat exchanger in the dilution cryostat 
internal pumping line. An other anomaly is the relatively high horizontal 
screen temperature around 80 K while during the run 2011 the same screen 
reached temperature of 27 K with same helium flow.

d) Yuri: test microwave feeding to the cavity. No leak between the cells
observed at this temperature.

e) Fabrice: feed about 10 A of current to the solenoid and dipole magnets.
Problem found in voltage measurement. 

Trying to improve turret heating. Small risk with the melting ice that
could produce a water bridge.

f) Johannes: the LHe production stop is planned for December 17. Cooling
water circuits will close on December 19.