Minutes from target meeting held on 5th of February 2003 in 892-1-B09

a) Jaakko asked if the hadron beam could cause radiation damage to our target
system if it will stay in place in case of hadron run. These would be 
190 GeV/c pions 2-3*10^7 /spill. Radiation damage to ECAL2 and silicon
detectors is expected. In addition there is plan to do calorimetry calibration
with low intensity electron beam with polarised target in place. Werner said 
that he does not expect that there is damage to polarised target. 

b) Since the switch from polarised target to hadron target has to be done in 
short time it is preferable to do the TE-calibration before the muon run.
Norihiro and Jaakko estimated 1 day to remove 3He/4He mixture, 5 days
to evaporate LHe from magnet and buffer dewar, 3 days to warm up the
mixing chamber to 100 K, 1 day for unloading, 2 - 3 days to remove LHe transfer
line, pumping lines and cables, and 1 day to rotate the platform. The
removal of the LHe can be done in parallel with the warming up of the mixing
chamber to 100 K. Thus this gives total time of 11 days with technicians and 
crane needed possibly also during the weekend. In this planning the magnet
will be cold below 100 K when the platform is rotated. Since the thermal
expansion will start only above 100 K this is probably the most safe 
procedure, but this has to be discussed with Saclay experts. The magnet
warms up the to room temperature in 2 months. Transverse mode will
be decided by the collaboration closer to the run.

c) The planning for 2003 was discussed. The cool down of the magnet was
moved two weeks earlier to start on 7th of April to get 2 weeks before the
run for testing target material properties. Thus the target loading is going 
to be done on 14th of April.

d) Stefan asked about the NMR coil problem of 2002. Jaakko explained that
there was a big ground loop around the upstream coils formed by the coaxial
cables, microwave stopper and 3He filling tube. The loop axis corresponded
to the most sensitive coil axis #1 and #3 while #2 and #4 were rotated
by 90 degrees with respect to this loop. Yuri proposed to add a plastic
part to the 3He filling tube to break the ground loop. Yuri wanted to
ask from Gerhard about possibility to get a scalar voltmeter for testing
the NMR circuit. Gerhard will visit CERN at the end of February. The
NMR tuning needs to be done in middle of March since the test loading
is planned on 24th of March.

e) Stefan wanted to fix the problem of target cell lids. The target
holder was transported to Bochum for reparation and will be back to
CERN at the end end of February. 

f) Yuri pointed out that the thermal shrinking should be taken into account 
when determining the target cell volumes and the material packing factor.
Stefan said that the coils should stay outside because of much better packing 
factor compared to 2001 when the coils were inside. Yuri said that the
Abragam and Saclay polarisation build up times for 6LiD were 3 - 4 times 
faster. Stefan said that this depends completely on system used, i.e. 
dilution cryostat, microwaves etc. Kaori said that the one loop 15 mm diameter
coil that was inside the target material in 2002 has too small inductance, 
small NMR signal and thus bad signal-to-noise ratio. The polarisation measured
by this coil is a little lower compared to coils outside.

g) Jaakko said that the magnet preparation and cool down needs to be 
coordinated with Jacques, Saclay and EP/TA3 help. Ales Srnka from Prague will
come to help in the cool down. Otherwise the target group has to do the
work in absence of Naoki.

h) The pumping system was discussed. The broken roots blower for 3He will be 
prepared by Pfeiffer if it can be prepared. The work started on 20th of
January and is expected to take 5 weeks. For the changing of the joints
in Alcatel 4He rotary pump there was a communication problem between CERN 
purchasing officer and Alcatel representative. Thus the order was only 
submitted on 14th of February. 

i) Stefan said that one new 1 W IMPATT diode system has been purchased and 
modulation on it has been installed. The modulation works ok up to 1 kHz.
Yuri said that we have 2 microwave PSUs and one new Nagoya PSU, 2 old EIO 
tubes, 1 new Nagoya tube, 1 SMC spare tube, and new cooling water box. 
The overall situation of the microwave system is good.

j) For the instrumentation the multireg has been serviced and is now ok.
There is no money left from Bochum to buy the Coulomb Blockage Thermometer.
The Yamagata 50 mm mixing chamber by Takahiro arrived at CERN on 7th of
February. The PLC system is being prepared.

k) Miroslav said that Stepan will be at CERN 1 month in February and 
3 months in summer from 17th June. Ales will come 3 weeks for magnet cool 
down and possibly for other 3 week periods.

l) Shifts were discussed. Fabrice said that the target group has 3 times 
higher shift load compared to the average load. There are two phases: the 
physics data taking and the preparation period before the run. The week
target coordination could be done also by external experts. From Prague 3 
persons more for the shifts than in 2002 are expected. The Japanese situation
is open. The preparation period takes 6 weeks. If there is hadron run this
would give for muon run 13 weeks*7*3 shifts = 273 shifts. Thus with one 
shift/week for one CERN target members gives 65 shifts. In addition 150 
shifts from collaboration and 65 from outside CERN target groups. 
For week coordination 13 weeks/5 - 10 = 1 - 3 shifts/ person. 

m) Publications were discussed briefly. Dead line for abstracts for the
Bad Honnef Polarised Solid Targets Workshop is 15th of June 2003.