Minutes from target meeting held March 30 2012 in 892-2-009

These minutes are available also from:

http://wwwcompass.cern.ch/compass/detector/target/Minutes/2012/

a) Plot the NMR-peak frequency versus polarization for polarization build
up 2010 September 10 and fit a line to this plot for each coil. For example
coil #6 

https://svnweb.cern.ch/cern/wsvn/ptpolaris/2010/plots/pdf/pol100910fvspN6.pdf

The error in fitting of the line is taken as the systematic error of possible
non-linearity. This gives a systematic error to the polarized signals
0.6 - 1.2 %. See more details in

https://svnweb.cern.ch/cern/wsvn/ptpolaris/2010/fshiftpol/fshiftpol10.txt

Note that the fitting parameters do not necessarily reproduce exactly between
the different buildups.

b) Estimate the total systematic error for the polarized proton signals 2010.
This includes the systematic effect from the choice of integration window 
(0.2 - 0.9 %), NMR circuit non-linearity (0.6 - 1.2 %) and polarization 
relaxation in 0.63 T transverse field (0.3 - 1.0 %). The total systematic 
error for the enhanced signals is 1.2 - 1.8 %. See 

https://svnweb.cern.ch/cern/wsvn/ptpolaris/2010/EnhErr/Enh10Err.txt

c) From the Gaussian fits to the thermal equilibrium NMR-signals the stability 
of the magnetic field could be estimated. This leads to a systematic error of 
0.05 % in the thermal equilibrium polarization at 1 K and 2.5 T. The gain 
stability of the Yale cards was estimated to add an error of 0.2 %.

d) Estimate the total systematic errors in 2010 transverse polarization 
values. After removing coil #1 from the calculations the transverse 
polarizations are

upstream     0.807+-0.0103(stat)+-0.0611(sys)
central cell 0.789+-0.0085(stat)+-0.0418(sys)
downstream   0.799+-0.0081(stat)+-0.0405(sys)

If the central cell is split into two halves the errors are

upstream     0.807+-0.0103(stat)+-0.0611(sys)
central up   0.782+-0.0158(stat)+-0.0414(sys)
central down 0.792+-0.0096(stat)+-0.0355(sys)
downstream   0.799+-0.0081(stat)+-0.0405(sys)

See https://svnweb.cern.ch/cern/wsvn/ptpolaris/2010/Run10/SysErr10.txt

e) Kaori: talk given in the JPS 66th Annual Meeting at Kwansei on the 
transversity physics of COMPASS. 

Removal of the NMR PXI crate from the experimental hall planned next week.