Formulation of the Binary-Encounter Approximation in Configuration Space and Its Application to Ionization by Light Ions

Oxygen inducedK-shell ionization of selected elements from sulphur to bromine

“…However, absolute cross sections are overestimated in most cases by more than one order of magnitude by PWBA, SCA and BEA calculations. Cross sections of the constrained BEA of Hansen [6] were found to be very little different from BEA curves shown in Figure 3 for the energy region of interest. The difference between PWBA and SCA curves is due to the Coulomb deflection effect which has been calculated in an approximation given by Basbas et al [10].…”

“…Inner-shell ionization via direct Coulomb interaction has been treated theoretically in different approximation schemes: the classical binaryencounter approximation (BEA) as formulated by Garcia and coworkers [5] and in a constrained version by Hansen [6]; the semi-classical approximation (SCA) by Bang and Hansteen [7]; and the plane wave Born approximation (PWBA) by Merzbacher and Lewis [8]. Direct Coulomb interaction theories have proven to be very successful in the interpretation of inner-shell ionization in collisions of light projectiles, as protons and alpha particles, with heavy atoms [1].…”

Charge distributions after ion-atom collisions

“…the Binary encounter approximation (BEA). Garcia [5], Gerjuoy [6], Hansen [7] and McGuire [8] developed slightly different methods to calculate impact parameter dependent probabilities within the framework of the BEA using Schr6dinger wavefunctions in the momentum or coordinate space. Harberger et al [9,10] succeeded in applying the BEA to compute the slowing down of energetic heavy charged particles in matter due to electronic collisions 9…”

Energy dependence of the x-ray production cross sections of Cu and Ag for 150 to 800 keV proton and He+ bombardment

“…Detailed reviews about inner shell vacancy production in ionatom collisions have been given by Garcia et al [1] and Rutledge and Kavanagh I-23. Most K-shell ionization experiments have been compared to the available theories: plane wave Born approximation (PWBA) [3], binary encounter approximation (BEA) [4] semiclassical approximation (SCA) I-5] and the PWBA theory with corrections for binding and Coulomb deflection effects (PWBABC) [6]. But it seems difficult to decide which theory is best since the discrepancies between the various measurements appear to be of the same order of magnitude as the difference between the theories.…”