Dear Georg,

Find below my paragraph on proton polarimeters.

Best regards,  Thomas

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Significant R&D effort is being conducted into relliable polarimetry of 
circulating polarized proton beams. The very small magnet moment of the 
proton makes it very difficult to use electromagnetic probes and therefore
nuclear reactions with a large figure of merit (cross section x analyzing
power^2) have traditionally been used. At lower energies elastic scattering
from carbon or hydrogen target or inclusive proton production from a carbon
target give fast polarization measurements with reasonably well know analyzing
powers. At energies above 20 - 30 GeV very few reactions are know to 
have sizable analyzing powers. Inclusive pion production at x=0.5 and 
pt=0.5 GeV was measured at 200 GeV and has an anlyzing power of 
about 20% but a polarimeter based on this reaction would require large 
spectrometers. Very small angle elastic scattering in the Coulomb-Nuclear-
Interference region (t~ -0.001 GeV^2) has a analyzing power of 2 - 4%
which is approximately independent of beam energy. A fast polarimeter 
was developed for RHIC using small angle scattering from a ultra-thin 
carbon target detecting the recoil carbon. For absolute beam polarization 
a polarized hydrogen jet target will be used which will allow the comparison 
of the jet polarization with the beam polarization using again the small-angle 
elastic scattering reaction. The jet polarization can be measured to about 3%. 
These last two polarimeters allow for fast and acurate polarimetery at all 
beam energies.