title: Electron momentum states and bremsstrahlung radiation from the ultraintense field ionization of atoms.
abstract: Relativistic continuum dynamics for electrons from the ionization of atoms in an ultraintense (10 to the 17th W/cm square to 10 to the 20th W/cm square) laser focus are analyzed using a semi-classical wavelet model. The results quantify the energy and angle resolved photoionization yields due to the developing relativistic dynamics in ultraintense fields. Using the final state momentum, the bremsstrahlung radiation yield is calculated and shows a linear relationship between the radiation cutoff and the laser intensity. At 10 to the 20th W/cm square photons with energies out to 10MeV should be observed. The results are quantitatively comparable to the observed angle resolved photoelectron spectra of current ultraintense laser-atom experiments. The results show the azimuthal angular distributions becoming more isotropic with increasing intensity.
authors.forename: Enam
authors.initials: E
authors.lastname: Chowdhury
authors.forename: Isaac
authors.initials: I
authors.lastname: Ghebregziabher
authors.forename: James
authors.initials: J
authors.lastname: Macdonald
authors.forename: Barry
authors.initials: B
authors.lastname: Walker