Minutes from target meeting held January 13 2012 in 892-2-009

These minutes are available also from:

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

a) Polarized target isolation vacuum stayed at about 1 mbar during the 
winter shutdown while mixing chamber was at 170 mbar. Pressurize the mixing 
chamber and helium-3 roots pumps to atmospheric pressure with helium gas on 
Tuesday. Remove the target holder from the mixing chamber. Close the mixing 
chamber with a metallic plug. The pump room temperature stayed above +4 C
during the winter shutdown.

b) Testing and repair of the dilution cryostat was discussed. The microwave 
cavity needle valve needs to be fixed before the next cool down. A helium 
leak test to isolation vacuum and between the helium-3 and helium-4 volumes 
is also useful. The new diffusion pump could be connected and tested
after the rotation of the target platform.

c) Measuring the cable length was discussed. One possibility is to use
a cable tester or a time domain reflectometer. The other possibility is to
measure the capacitance of a disconnected cable. It is also possible to 
use a rope with markings pulled parallel with the cables. 

d) Yuri: unmount the microwave guides from the control room to the platform
on Tuesday.

e) Kaori: the old or new Q-meter circuit should be tested for radiation 
hardness with neutrons for the Drell-Yan polarized target. Possibility to
buy a new EIO generator tube from CPI is being discussed at Yamagata.

f) Jaakko: calculate preliminary polarization for each physics+ or physics-
run in 2011. See http://wwwcompass.cern.ch/elog/target_polar/155

Some jumps seen in the calculated thermal equilibrium areas. These need 
further analysis.