Minutes from target meeting held on 30th of January 2003 in 892-1-B09

a) Norihiro asked how much time will be used for transverse mode next summer
and when do we make the microwave polarisation reversals. Jaakko said that
even the possible hadron programme has not yet been decided and will be 
discussed during the next collaboration meeting.

b) Summer students for target were discussed. The dead line for the student
project proposals is 12th of February. More information available from CERN
Human Resources web page:
http://humanresources.web.cern.ch/humanresources/internal/default.asp

c) Kaori and Yuri presented summary of their polarisation calculations for
run 2002. Yuris polarisation data starts from 6th of July while Kaori analysed
the whole period from 18th of June to 18th of September. Yuri presented 
the average upstream and down stream polarisation values for the different
isotopes deuterium, 6Li, 7Li and protons. Jaakko said that the plot could
include simple table of the relative abundance of each isotope. 

Kaoris polarisation data was only for deuterium but polarisation measured by 
each coil #1 - #4 and #6 - #10 was presented. Kaori had done corrections for 
the influence of microwaves and field rotation to signal area. These were 
summarised in a short report. Yuri said that average polarisation does not 
depend on field rotation and considering each coil separately is not very
useful. Jaakko said that for the moment average up/downstream polarisation
is enough for the collaboration, but if longitudinal distribution is required
we should give them that too. A summary table to compare run 2001, Kaoris 
and Yuris results should be made. 

Yuri said that many of the collaborators don't understand the spin 
magnetisation direction with respect to solenoid field. Jaakko said that this 
would be easy to explain to collaboration: for positive polarisation the three
level population is concentrated on the lower energy levels while for the 
negative polarisation it is concentrated to higher energy levels. In the NMR 
we see voltage drop in the Q-meter for positive polarisation while in negative
polarisation case the voltage is increasing at resonance. Yuri said that we 
should not teach the collaboration solid state physics. For the polarisation 
error estimation also the temperature data needs to be summarised.

d) Shifts for next summer were discussed. Fabrice proposed that target 
experts from outside CERN could do also target week coordination shifts.
Jaakko said that this is ok if these people agree to do it. The shifts
in 2001 were done entirely by the target team. In 2002 the CERN target team 
did one shift/day to guarantee stable operation of the target. This lead
to big shifts load. On the other hand there were also hidden shifts
especially during the polarisation when the microwave experts did not trust
the other collaborators in setting the parameters while building the 
polarisation. Fabrice said that CERN target groups shift load is too much
compared to other collaborators. Jaakko said that taking care of the target
is our main activity and we are not taking part to physics data analysis.
Fabrice said that this is because we are very busy in the preparation work
for next run. Anyway this point should be discussed in the next bigger target
meeting.


e) Program before physics run 2003 will be discussed next Wednesday in the
bigger target meeting.

f) Yuri suggested that it would be interesting to check also the NMR signals 
of 6Li, 7Li and proton after observed loss of polarisation due to 
superradiance.

g) Inside/outside coils were discussed. Jaakko said that the 2001 and 2002 
filling factors suggest that we get better filling with coils outside.
For 2001 these were 0.50 for downstream and 0.45 for upstream and for 2002 
0.56 downstream and 0.50 upstream. The upstream smaller filling factor 
was discussed. Norihiro said that the target holder is more horizontal in 
the beginning of the material loading and is thus easier to fill. In the end 
when the upstream cell is being filled it is very much tilted. Yuri said
that it would be good idea to place the small inside coil in the centre
of the target cell. Yuri said that in SMC 5 % difference between 
inside/outside polarisation measurements was observed. Jaakko said that we 
do not understand even the longitudinal distribution yet, so the radial
distribution may not be so interesting.

h) Yuri said that with EPR-line saturation a 500 Hz shift of deuterium
NMR signal is expected. The F-centre concentration of our material is
twice higher than in the Abragam paper J. Magn. Res. 22 (1976) 53. This 
method could be used to measure the concentration of the F-centres and
the relaxation time of these centres.

i) Fabrice wanted to communicate the new offline polarisation data to 
the experiment database which now contains only the online values.
The new Oracle database has been implemented for the target web page. 
Now there is history of the parameters available by clicking the parameter
name. 

j) Jacques informed that Saclay could provide new gas heaters for the SMC
magnet and fix leaks on SMC magnet around these heaters and on the top of
current leads. The Saclay experts will visit the installation in the 
beginning of the March.