TRIPLE DIFFERENTIAL CROSS-SECTION MEASUREMENTS FOR KR(3D) ELECTRON-IMPACT IONIZATION

Triple differential cross sections have been measured for the electron -impact ionization of the 3d orbital of krypton. The measurements have been performed in asymmetric coplanar geometry at incident energies a round 1 keV, and ejected electron energies of 72 eV (corresponding to bound Bethe ridge conditions) and 50 eV. Both of these energies are si gnificantly below the binding energy of the 3d orbital of approximatel y 94 eV. The measured cross sections are compared with calculations pe rformed in the distorted-wave Born approximation and the distorted-wav e impulse approximation. There is quite good agreement in the former c ase, but no agreement in the latter, despite kinematics which should e mphasize the impulsive nature of the collision.