Polarization experiments with electron accelerators

There has been a shift from large-current pulsed electron linac to continuous electron beam accelerator as a means of electron acceleration, mainly because 'exclusive', rather than 'inclusive', experiments have become necessary to permit detailed physical analysis. Polarization experiments, as well as coincidence experiments, are a major purpose of most of the new electron accelerators currently under plan or under construction. Thus, greater attention has been focused on the application of electron beam to polarization experiments as more efforts are made to make wider use of an electron accumulating ring. An important objective of polarization expperiments is to perform detailed analysis of the electromagnetic nature of atomic nuclei. Brief theoretical discussion of such nature is made on the basis of the electron scattering cross section, focusing on structure functions. For coincidence experiments, so-called out-of-plane observation is required to determine the structure functions separately. The combination of coincidence and polarization experiments can provide useful data for detailed analysis of the nature of nuclei. Some examples of such experiments are also described. (N.K.)