Minutes from target meeting held October 12 2007 in 892-1-D20

These minutes are available also from:

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

a) Saturday October 6 around 23:00 PLC CPU failure again. After reset 
and restart of vacuum pumps normal operation recovered. Jaakko: the CPU has 
the smallest MTBF (see target Wiki) so it was changed. Other possible reasons
power supply unit or micro power cut in 48 VDC network. The IT communication
processor firmware needs to be updated. Could be moved to COMPASS network, but
then only access through the gateways. Norihiro: program was running ok in 
2006, so it is unlikely to be the reason. 

b) Claude: MD on Wednesday October 10 08:00. Go to longitudinal 2.5 T with 
polarizations -82.2 %, +77.1 % and -77.5 %. On Thursday 18:00 back to 
transverse field with polarizations -89.2 %, +80.8 % and -83.9 %. 

c) Jaakko: polarized NH3 molecule simulations. The central NH3 has three 
acceptor molecules on plane 2.494 A above and three donors 0.468 A below.
The molecule is rotated with random Euler angles. The second moment of the 
NMR signal is calculated. This technique is similar to the powder average 
found from text books. The second moment does not depend on the polarization 
in this model. 90 % polarization gives about 10 kHz average frequency shift 
due to the local field. At the same time the dipole shifts to +20 kHz are 
enhanced while the -20 kHz are suppressed. Histograms in Elog.