ELECTRON-SCATTERING WITH POLARIZED BEAMS AND HE-3-TARGETS

The first part of the paper deals with some typical experimental situations met in scattering of polarized electrons from unpolarized and polarized targets. One example described is the measurement of parity violation measured in quasi-elastic scattering of polarized electrons at the 300-MeV Mainz-Linac. The main problems posed by this kind of experiments lie in achieving the necessary statistical and systematic error limits which have to be well below 10-6 in order to detect the parity violating asymmetry. Much larger asymmetries can be observed in parity conserving, purely electromagnetic scattering processes. However, they require polarized targets in addition or polarization analysis in the final state. Such experiments can reveal fundamental insight in the electromagnetic structure of the nucleons. The d(e,e′n) and 3He(e,e′n) reactions are discussed as examples. The second part briefly reports on the status and performance of polarized GaAsP-electron sources. The third part deals with polarized 3He targets. Attempts to build a dense 3He target, obtained by compressing an optically pumped 3He vapour are described in particular. © 1990.