Moller Measurements for E97-110 (GDH), July-August 2003

Last updated: Thu, 13 Aug 2003 gen@jlab.org

Here a summary is given of the Moller measurements done for E97-110 The GDH Rule and the Spin Structure of ³He and the Neutron Using Nearly Real Photons running in July-August 2003.

The results have been corrected for the leakthrough from Hall C. The final value of polarization in Hall A (the column marked "Leak. corr.") contains the systematic error estimate, associated with this correction. The other systematic errors are about 3% relative. The statistical errors are about 0.2% absolute. The polarization sign convention is opposite to the one used for HRS analysis and Compton polarimeter. The polarization is positive, if the beam particle helicity is +1 during the period when the NIM polarization signal is at logical unit (-0.8V).

The last column presents an estimate of the injector polarization, obtained using the spin angle prediction, in order to check the stability of the results. The sign flip in the measurements 3-5 is understood (it was caused by an accidental removal of a HWP from the injector at the given time period). The error given is associated with the accuracy of the precession angle calculation, with the beam energy accuracy of 0.05%.

  # date         1-st     Energy, GeV     N         spin       Polarization in A       Injector
  #  m  d  h      run    beam   linac   pass  HWP   turns   not corr.   Leak. corr.    polariz.
  1 07 17 22    10907   2.1366  0.51955   2    0    4.041     0.723     0.737 +/-0.4    76.2 +/-0.3
  2 07 21 18    10932   2.1366  0.51955   2    1    4.041    -0.721    -0.746 +/-0.6    77.2 +/-0.3
  3 07 26 00    10956   4.2169  0.51981   4    0   17.921    -0.602    -0.652 +/-1.2   -74.3 +/-2.1
  4 07 28 19    10982   2.1374  0.51975   2    1    4.043     0.725     0.747 +/-0.5   -77.5 +/-0.4
  5 07 31 20    11001   2.8492  0.46615   3    1    9.022     0.737     0.767 +/-0.7   -77.5 +/-0.5
  6 08 08 19    11030   3.7818  0.46619   4    0   16.041     0.764     0.765 +/-0.03   79.0 +/-1.6
  7 08 14 19    11047   1.1482  0.54355   1    0    1.041     0.758     0.762 +/-0.1    78.8 +/-0.1
  8 08 16 19    11048   2.2359  0.54369   2    0    4.522    -0.751    -0.761 +/-0.2    76.8 +/-0.1
  9 08 21 23    11085   4.4153  0.54427   4    0   18.990     0.751     0.756 +/-0.1    75.8 +/-0.1
 10 08 25 21    11104   3.3241  0.54383   3    1   10.510     0.774     0.778 +/-0.1    78.0 +/-0.1

The details of the measurements can be found here.