The Studies Of The Photodetachment Cross Section Of H-in Anti Parallel Electric And Magnetic Fields

In the present thesis, we give the semiclassical treatment of the photodetachment of H- in anti parallel electric and magnetic fields. Using cylindrical coordinates, we express the equations of motion of the detached electron from which the conditions of returning of the orbits are given. Taking advantage of the bifurcation theory, the bifurcations of orbits of the electron are described. Using semiclassical approximations, the photodetachment cross sections are calculated and the relevant spectra are determined. The general relationship between the closed orbits and the photodetachment cross section is given. The cross sections ,as function of the energy E and the electric and magnetic fields strengths,depend also on the orientation of the two fields . Expected results are obtained and are in good agreement with those obtained by Peters, Jaffe and Delos [5],and in this respect, some comparisons with the case of parallel electric and magnetic fields are done.The phases of the oscillations depend on the polar angle O~ which depends on the orientation of the fields.The structures of the oscillations are function of the magnitude of the dimensionless scale variable R, which measures the relative effects of the two fields. As the magnetic field strength increases, the wave amplitudes of the oscillations also increases and when its magnitude is greater than 60T,some discrepancies appear due to the rescattering effect. It 憇 that the characteristic of the general non linear phenomena.