Minutes from target meeting held July 23 2010 in 888

These minutes are available also from:

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

a) Restart to polarize on Thursday 13:00. +77.7 %, -77.2 % and +77.9 % reached
by Friday 13:00.

b) Short meeting with Laura on the helium-3 roots spare motors at 16:00 on 
Monday. The motor coils could be tested with a multimeter. It is possible
to connect also electricity to the coils though the rotor is probably attached
to the rotating shaft inside the pump. The motor replacement can be done
in principle, but the list of needed materials and the exact procedure are 
missing.

c) Gunter: contact Pfeiffer for servicing the helium-3 roots blowers. Similar
service that was done 12 years ago could still be done. The motors are not
produced any more however. The time schedule in the previous service was: 
pumps sent to Pfeiffer in November and back at CERN in June. Jaakko: this did 
not include any service to the control cabinet.

d) Slow control for the helium-3 roots blowers was discussed. The protection
is now by simple on/off relays and manual switches. There is no PLC or PVSS 
like in the new helium-4 pump system.

e) Test reading of the pt100s on the helium-3 roots motors from the PLC with
help of CERN Siemens PLC support. After replacing the terminal modules (TM-E)
the 2 AI RTD modules started to read correct values from the pt100s in
the pump room.

f) Kaori: increase the voltage to the upstream microwave attenuator step motor
control from 24 V to 36 V (Yui). The remote control did not work in 2.5 T field
however. The motor is in high field region next to the entrance of the 
microwave guides.