ON THE EIKONAL THEORY OF POTENTIAL SCATTERING IN THE PRESENCE OF A LOW-FREQUENCY LASER

We investigate the eikonal theory of charged-particle potential scattering in the presence of a laser when the collision time is much smaller than the laser period while the translational velocity of the particle is much larger than its classical oscillatory velocity in the field. Our detailed numerical calculations show that for small scattering angles, previous eikonal results of the Kroll-Watson type, based on a stationary phase approximation (SPA), are inaccurate for differential cross sections and become worse as one increases the range and/or the strength of the potential. We replace the SPA by a different approximation, ideally suited to small-angle scattering and obtain excellent agreement with the 'exact' numerical results.