Preliminary result of the target polarization 2004

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Preliminary resultof the target
polarization2004

• Kaori Kondo
• COMPASS target team

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Polarization measurement 2004
downstream cell
upstream cell
120
outer coil
inner coil (coil 6)
Coil 6 does not work.
60 mm
f 15 mm
f 30 mm
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NMR signals
magnetic field direction
(spin anti-parallel to the field)
negative polarization
(spin parallel to the field)
positive polarization
always monitored!
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building up polarization
typical polarization buildup
polarization ()
1 day 42 -40 2 days 47
-46 3 days 50 -48 5 days 52
-49
day
relaxation time
at 60 mK 2.50 T (normal frozen mode) 15000
hours at 60 mK 0.42 T (transverse mode)
1400 hours
lost 0.7 in 2 weeks lost 23 in 5 days
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TE calibration
Period Temperature (K)
5 May 7 May 1.52
7 May 9 May 1.28
9 May 12 May 1.17
9 June 12 June 1.00
12 June 14 June 1.32
We had very good calibration with 5 temperature
points.
Errors from TE calibration can be about 1
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upstream
relaxation time measurement
TE calibration
transverse
2 Aug. cooling water pressure
downstream
20 Aug. cooling water stop
thanks to Isabel
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H E L P ! !
We would like target shift crews 21 Sept. 4
Oct.
Still 13 shifts are not occupied.
Experienced people are welcomed.
Have a look on http//compass-target.web.cern.ch
/compass-target/ -gt shiftlist.
Contact with Fabrice Gautheron for
volunteering! Fabrice.Gautheron_at_cern.ch
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