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 6.0×1019s−1mm−2mrad−2 at 10MeV and 1.4×1019s−1mm−2mrad−2 at 100MeV (0.1% bandwidth).Comment: arXiv admin note: text overlap with arXiv:1310.328