Photodetachment of a Homo-Nuclear Linear Tetra-Atomic Negative Molecular Ion

The photodetachment of a homo-nuclear linear tetra-atomic negative molecular ion is studied theoretically for an arbitrary laser polarization. An expression for the total cross section is obtained by using an extended version of the two center model, where each center acts as a source of coherent photodetached-electron waves. Strong oscillations on observation plane, placed at a large distance from the ion, are observed. The amplitude of these oscillations is maximum when the laser polarization is parallel to the molecular axis. Furthermore, the amplitude decreases as the angle between the laser polarization and molecular axis increases and consequently vanishes when they are perpendicular to each other. It is also found that if the distance between the adjacent centers is very small or very large, then the amplitude of oscillations is negligibly small.