Minutes from target meeting held June 11 2010 in 892-1B-09

These minutes are available also from:

http://wwwcompass.cern.ch/compass/detector/target/Minutes/2010/

a) Fabrice: chilled cooling water to the isolation vacuum pumps lost on
Friday. The water recovered at 17:20 after TCR intervention. Condensation water
dropping from the DAQ barracks air conditioning unit to the polarized target 
storage area on Sunday. Problem fixed Monday. Alarm from magnet upstream neck
temperature. Readjust heater threshold. Fill cooling water to the NMR cable
heat exchanger. Correct the position of upstream neck heater cable on
Wednesday. 

b) Magnet safety system (MSS) repaired on Wednesday. Blown fuse replaced.
Probably problem in fuse status indicator wiring. Fabrice: ramp up the
solenoid after repair to 2.5 T and test the field rotation and the program 
to go to transverse field from longitudinal mode.  

c) Condense helium-3 on Thursday morning. Ramp up the solenoid to 2.5 T 9:45.
Start the microwaves, NMR and start to polarize with still heater 12 V 10:30.
Friday 8:30 to transverse frozen spin mode with polarizations -78.2 %, +76.6
% and, -78.4 %. For a test go back to longitudinal mode with polarizations
-77.5 %, +76.6 % and -77.9 %. Start to take physics data in transverse mode
10:15. 

d) Fabrice: cryogenic operators should be informed 2 - 3 days in advance about 
planned extra consumption of helium-4. For example in case of polarization 
build up. Contact person is Laura.

e) CERN support for the new helium-4 pump group was discussed. There could be
possibility to add similar PVSS system to the dilution cryostat PLC managed
now by the polarized target group. Probably from the COMPASS DCS system.

f) Jaakko: the magnet transistor bank cooling water line could be protected
with an overpressure valve that starts to leak out if high pressure is
reached (~ 8 bar). 

g) Kaori: NMR rack water cooler needs to be checked and refilled by the target
week coordinator. The PXI-crate to NMR PC communication stops about once per
day. The shift needs to press 'continue' on the pop-up window. No polarization
measurement is done now during the transverse data taking. In 2007 the
polarization measurement in dipole field was fluctuating a lot and was not
finally used in offline data production. The measured online polarization
data values are now available from the COMPASS run logbook MySQL database. 

h) Jaakko TB talk in:

http://wwwcompass.cern.ch/compass/detector/target/Talks/koivuniemi_10_6_2010.pdf