FINE-STRUCTURE EFFECT FOR (E,2E) COLLISIONS

For the case of inelastic electron-atom scattering, it has been known for some time that significant spin effects may be observed even if sp in-dependent forces on the projectile can be ignored. These spin effec ts result from the Pauli principle and this phenomenon has become know n as the fine-structure effect. Recently, the question of whether or n ot these same types of effects should be observed for atomic ionizatio n has been considered and the initial indications are that significant spin asymmetries can also be expected for atomic ionization if the fi nal ion satisfies LS coupling and the final J state of the ion can be resolved. In this paper, we consider this problem for electron-impact ionization of inert gases. The theory of the fine-structure effect is presented for ionization and first-order distorted-wave results are co mpared with very recent experimental data.