Minutes from target meeting held November 8 2007 in 888

These minutes are available also from:

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

a) Takuma: field rotation from negative to positive solenoid current Saturday 
morning 09:00. Sunday water problem in SPS, no beam. Beam back on Monday 14:00.
Tuesday night at 02:00 diffusion pump stopped. PLC reset. 09:00 field rotation
from positive to negative current and Wednesday from negative to positive.
Thursday MD at 08:00. About 2 % polarization lost in 9 days. One shift missing
due to sickness on Thursday.

b) Yuri: polarize from positive value to negative to see the NMR frequency 
shift during build up after 30 min relaxation at 0 T. 

c) Nitrogen-14 and -15 NMR and NQR was discussed. Polarized nitrogen-15 should
be visible around 10.84 MHz at 2.5 T (natural abundance 0.37 %). The zero field
NQR of nitrogen-14 could be around 7 MHz, but this value depends strongly on 
the electric field gradient inside NH3 crystal. Nitrogen-14 polarization is 
not very big, only 10 - 14 % when the protons are polarized to more than 80 %. 
In low temperature physics nuclei with quadrupole moment are avoided to 
suppress the quadrupole heat capacity. In Phys. Rev. C 42 (1990) 2222 the 
polarized nitrogen-15 has similar asymmetric line shape like is observed for 
the highly polarized protons in ammonia-14.