QUASI-FREE ELECTRON-SCATTERING ON ATOMS IN THE INVERSE KINEMATIC SYSTEM

The measurement of elastic electron scattering is a sensitive tool to test ionic and atomic potentials. Because a dense ionic target is diff icult to produce, we use inverse kinematics, i.e. we exchange the role s of projectile and target and transform the cross sections. The absol ute singly and doubly differential cross sections for the projectile i onization of He-0 (0.1 MeV/u) scattered by Ne-0, measured for the dire ct and the inverse system in the whole angular range from 0 degrees to 180 degrees, show the validity of the transformation, We find a prono unced generalized Ramsauer-Townsend minimum in the angular-dependent s ingly differential cross section, Changing to the Ne3+ target the loss peak is absent in our measurements for larger emission angles. This m ay be explained by a large capture cross section into bound states of the neon ion, which depends on the impact parameter.