Cooling and phase space control by using laser-undulator beat wave

In order to control and manipulate internal phase space structure of charged particle beam, we present a general theory to use ponderomotive force between undulator and laser wave packet which is appropriately designed by employing coherent multiple discrete modes. We applied the method to an electron beam system which is shortly bunched in storage ring and demonstrated by computer simulation that the longitudinal energy spread is efficiently cooled in much faster time scale than the conventional synchrotron radiation cooling. The scattered laser light is found to preserve statistical characteristics of cooling related to the entropy exchange between beam and laser. The cooling in phase space is found to result from entropic resonance which is different from the usual wave-particle resonance. copyright 1996 American Institute of Physics