Minutes from target meeting held November 16 2007 in 888

These minutes are available also from:

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

a) Longitudinal data taking finished on Sunday November 11 at 9:00. Start
preparation of Drell-Yan test with pion beam intensity of 10^7. Check 
polarizations at 2.5 T field from 11:00 to 16:00. Go to 1.0 T solenoid field
at 16:40. End of beam Monday 7:00. 8:30 back to 2.5 T solenoid with 
polarizations -86.2 %, +78.3 % and -79.8 %.

b) Try to measure polarized nitrogen-15 signal around 10 MHz without retuning 
the Q-meter. No signal seen. After this stay 30 minutes at 0 T and go back 
to 2.5 T. Rebuild polarization with opposite sign to check the NMR lineshape. 
Go to 0 T at 19:00 and start removing helium-3/4 mixture.

c) Tuesday November 13 safety valves to open circulation. Start condensing 
helium-4. Problem with helium-3 vapor pressure baratron. The control unit
gives wrong pressure values. TTH4, TTH5 and helium-4 vapor pressure used 
instead. At 16:00 the nominal liquid helium level reached in the cryostat. 
Thermal equilibrium calibration temperatures 1.5 K, 1.3 K and 1.0 K used.
Kaori: First analysis is consistent with the calibration done in May 2007.

d) Fabrice: Power cut scheduled for Thursday 7:00 - 7:10. Ramp field to zero
at 6:00. Stop NMR and stop the dilution cryostat pumps. All networks down
except the 48 VDC. UPS network did not restart automatically. Cooling water
recovered only 45 minutes later. Magnet cryogenic control PC hard disk lost.
At 14:00 restart slow control. The liquid helium level dropped to 80 %.
90 % level recovered at 15:00 and magnet restarted.