Enhancing Bremsstrahlung production from ultraintense laser-solid interactions with front surface structures

We report the results of a combined study of particle-in-cell and Monte Carlo modeling that investigates the production of Bremsstrahlung radiation produced when an ultraintense laser interacts with a tower-structured target. These targets are found to significantly narrow the electron angular distribution as well as produce significantly higher energies. These features combine to create a significant enhancement in directionality and energy of the Bremstrahlung radiation produced by a high-Z converter target. These studies employ short-pulse, high intensity laser pulses, and indicate that novel target design has potential to greatly enhance the yield and narrow the directionality of high energy electrons and γ -rays. We find that the peak γ -ray brightness for this source is 6.0 × 10 19 s −1 mm −2 mrad −2 at 10 MeV and 1.4 × 10 19 s −1 mm −2 mrad -2 at 100 MeV (0.1% bandwidth).