ELIMINATION OF INSTRUMENTAL ASYMMETRIES IN ELECTRON POLARIZATION ANALYSIS

Recent advances in polarized-electron sources had the consequence that the accuracy of many experiments with polarized electrons is no longer limited by statistics, but rather by the uncertainty in polarization analysis by Mott scattering. One of the reasons for this uncertainty is spurious asymmetries that are caused by a small misalignment of the polarized beam. This article discusses how spurious asymmetries can be corrected for by proper use of monitor counters. It is shown that such a correction requires proper positioning of the monitor counters. A method of finding and checking the correct analyzer arrangement is given. The result is a polarization measurement with high reproducibility and accuracy.