  We report the creation of super-high-flux gamma-rays with energy >8 MeV and
photo-neutrons via the (g,n) reaction near giant dipole resonance energies (8 -
20 MeV), using the ~130 J Texas Petawatt laser to irradiate high-Z (Au, Pt, Re,
W) targets of mm - cm thickness, at laser intensities up to ~5x1021W/cm2. We
detected up to ~ several x 1012 gamma-rays > 8 MeV (~3% of incident laser
energy) and ~ 1010 photo-neutrons per shot. Due to the short pulse and narrow
gamma-ray cone (~17o half-width) around laser forward, the peak emergent
gamma-ray flux >8 MeV reached ~1027 gammas/cm2/sec, and the peak emergent
neutron flux reached ~1020 neutrons/cm2/sec. Such intense gamma-ray and neutron
fluxes are among the highest achieved for short-pulse laser experiments. They
will facilitate the study of nuclear reactions requiring super-high-flux of
gamma-rays or neutrons, such as the creation of r-process elements. These
results may also have far-reaching applications for nuclear energy, such as the
transmutation of nuclear waste.
