Theory and simulation of high intensity laser plasma interactions.

Vacuum scattering of electrons by an intense laser field is considered. This phenomenon is shown in many cases to be a polarization independent effect for arbitrary angle of incidence by an electron on a linearly polarized laser pulse. As the laser intensity grows and the focal volume shrinks, however, this independence fails. The corresponding electron energy and laser intensity transition is derived here for the first time. Such vacuum scattering is found to be driven by several mechanisms that occur over several scale lengths. Using both plane wave and focused laser field models, the relative importance of each is probed. In addition to extending the state of the art TEM00 to eighth order in the diffraction angle, an independent solution to the full Maxwell wave equation is also derived here based on the spectral methodology in which the imposed transverse laser fields are purely Gaussian in the focal plane. This is compared to the series expansion and found to be a distinct solution. Finally, this method is extended to allow for an arbitrary super-Gaussian transverse field profile boundary condition in the focal plane. After addressing these fundamental physics problems, some discussion of applications is given. First, the Thomson scattering cross section is derived for all laser intensities and electron energies. This allows the total amount of energy scattered by a Maxwellian electron beam to be computed: a useful experimental quantity. Following this, a simple, intuitive model is developed to calculate the brightness of a Thomson light source in a given frequency band. This is then compared to experiment and used to estimate the brightness of such a source driven by Z-Beamlet. Finally, a tunable infrared source is theoretically demonstrated. Electrons trapped in a standing electromagnetic wave tend to oscillate within the ponderomotive potential well. This bounce frequency and the laser frequency mix creating several intermodulation products that are manifested in the Thomson scattered spectra. For intensities on the order of 1017 W/cm2 , this phenomenon will scatter light along the laser polarization in the near infrared regime.Ph.D.Applied SciencesElectrical engineeringElectromagneticsOpticsPure SciencesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/124931/2/3163927.pd