X-ray generation by Compton scattering of elliptically polarized laser light at relativistic radiation powers

The generation of short X-ray pulses is presently a topic of great practical interest. One of the possible mechanisms to achieve this goal is Compton scattering at very high laser powers. In order to find out under which circumstances this process is most efficient, we investigate nonlinear Compton scattering in an elliptically polarized laser field at very high kradiation power such that the ponderomotive energy of the target electron is larger than its rest energy, i.e., U-p greater than or equal to mc(2). We investigate in detail the polarisation dependence of the efficiency of the laser-induced nonlinear Compton processes of the order N of absorbed laser photons omega, assuming that the electrons are at the surface of a solid target. In the case of metals, the electron binding energy can be neglected at the laser powers considered but the electron density of some 10(21) cm(-3) will enormously enhance the efficiency of the process of X-ray generation. The present work is a generalization of our previous analysis of Compton scattering in a linearly polarized laser field (Phys. Rev. A 65 (2002) 022712). (C) 2002 Elsevier Science B.V. All rights reserved.