Minutes from target meeting held 22nd March 2002 in 892-2-009 14:30

a) Summer student from Italy was selected on Monday for period 2.7. - 27.9.

b) The roots pump #16 from Pfeiffer service was installed back to the pumping 
system of 3He. The volume between roots #13 and electro-pneumatic valve was 
leak tested before reconnecting the piping to roots #13. 

c) One of the coaxial vacuum feed throughs from TH to mixing chamber is 
leaking and needs to be repaired.

d) Support ring for TH came from Helsinki workshop. Loading of the target
has to be practised while still at room temperature.

e) Kaori estimated the proton content of the deuterium in the target to be 
0.46 - 0.55 % from the NMR-signals. The estimation is difficult due to to
the broad proton background. Tuning of the NMR coils is in progress.

f) Yuri used the local field change due to polarised spins to estimate the
deuterium spin density in the target material. For 6Li, 7Li and p a relative
value based on their abundance in the material was obtained. The spin
density for deuterium was estimated to be 3.975 10^22 spin/cm^3. Yuri raised
the question of 3He polarisation. The typical magnetic relaxation time of
3He at 80 mK is 8000 s. It might be interesting to check the NMR-signal
of 3He also during the frozen spin mode or to try to measure the
temperature dependence of 3He NMR signal size. Jaakko pointed out that
3He signal is very narrow and there was some indication of its saturation
due to high RF field in run 2001. The small satellite seen in the deuterium
NMR signal was discussed. There are at least three different possibilities:
water on the surface of the beads (= magnetic oxygen?), free D2 or lattice 
defects which produce a quadrapole shifting of the NMR-signal. Norihiro 
proposed a simple method of measuring the weight of the target material to 
determine the spin density. This technique was also discussed.

g) Fabrice is making the PVSS - LabVIEW connection. There is problem about
a license, since the CERN license is only for LHC.

h) Norihiro is preparing the pt100s. Yuri proposed exchanging the speer
up and speer down the target cell.

i) Gunter asked why kapton foil was not used in the construction of the
new target cell. Jaakko said that only the NMR coils are being replaced.
Otherwise the target cell will remain as it was in 2001. Also one has to
worry about the free conduction of 4He to cool the beads.