A b s h c t Electron impact ionization of hydrogen in its 2s metastable state is investigated theoretically. An ob initio calculation is proposed which includes the carelated double continuum Brauner-Brigs-Klar (BBK) wavefunction. ' The results of this model are compared with those given by the use of the second Born approximation, Some interesting kinematical situations are explored for future experiments.

Abstract. Electron impact ionization of Lithium in its ground state is investigated theoretically. An ab-initio calculation is proposed which includes the correlated double continuum Brauner-Briggs-Klar BBK wave function [8]. The results are in good agreement with the existing experimental measurements and partial wave calculations for the symmetric case. Some interesting kinematical situations are explored for near future experiments and the similarity with the ionization of hydrogen (2s) studied.

Absbact The differential cross section of the ionization of hydrogen in its n = 2 degenerate state by electron impact is investigated theoretically by applying the correlated double continuum wavefunction satisfying the exact asymptotic conditions. The levels 2~ and Zp,, , being energetically undistinguishable from the 2s in a coincidence detection, contibute equally to the differential cross section and show some interesting interference structures. The comparison of the results with those obtained by simpler procedures like Coulomb projected first Born calculations shows the importance of having the correct asymptotic behaviour in the final state, specially for small scattering angles. This work constitutes a necessary step for future calculations concerning complex atoms, whose wave. functions could be constructed by 2p0 and Zp,, orbitals.

This study aims to determine the effectiveness of hybrid engineering technology to be applied to the groin to reduce longshore currents. The application of hybrid engineering as a breakwater and sediment trap in coastal areas has given good results so that it can be developed in permeable groin structures. The research method used is laboratory experimental with physical modeling to make prototypes and conduct tests on the wave flume to determine changes in current velocity against the existence of a hybrid engineering structure with several model scenarios by changing the characteristics of brushwood groin such as length and distance between groin to surface height. water. The expected result of this study is an engineering model of the permeable groin that can function as an efficient and effective hybrid engineering in reducing longshore currents.