Minutes from target meeting held May 24 2007 in 888

These minutes are available also from:

http://wwwcompass.cern.ch/compass/detector/target/Minutes/2007/

a) Stephane: target shifts have been filled until middle of August.

b) Yuri: the middle target cell was polarized from Tuesday evening with high
microwave power. Using lower power did not change the buildup rate. The speer
resistor indicates about two times higher power than in the SMC. The frequency
modulation is the same like in SMC about 7 kHz/15 MHz. The NMR signals
shift when the SM1 is switched on or off.

c) Kaori: the Q-meter varicap power supply has problems. If the NMR signals 
are not recorded correctly need to be switched off and on. 

d) Norihiro: new PLC I/O modules were installed to the control room and to
pump room. Cabling from the magnet is being prepared. 

e) Jacques: 4He was removed from the dilution cryostat and the 3He/4He mixture
was condensed on Monday. Tuesday morning 65 mK temperature was reached. 
Polarization was started on Tuesday evening 19:00. In 18 hours 60 % was 
reached in the middle cell. The magnet procedure from 2.5 T to 0.6 T dipole 
in deuteron mode was tested. Then from 0.6 T dipole to 2.5 T solenoid in
proton mode.

f) Jaakko: first attempt to fit the proton signals to the SMC model of three
protons in triangle with total spin -3/2, -1/2, +1/2 or +3/2. Due to 
the dipolar coupling between the spins the three NMR lines are not exactly 
at the same frequency. Three equally spaced gaussians can be fit to 
the highly polarized proton signal. The fit parameters are in agreement
with the values published by the SMC. The fit would suggest rather high
polarization of 82 - 92 %.