Intenseγ-Ray Source in the Giant-Dipole-Resonance Range Driven by 10-TW Laser Pulses

Abstract

A $\gamma$-ray source with an intense component around the giant dipole resonance for photonuclear absorption has been obtained via bremsstrahlung of electron bunches driven by a 10-TW tabletop laser. 3D particle-in-cell simulation proves the achievement of a nonlinear regime leading to efficient acceleration of several sequential electron bunches per each laser pulse. The rate of the $\gamma$-ray yield in the giant dipole resonance region ($8<E_{\gamma }<17.5\mathrm{MeV}$) was measured, through the radio activation of a gold sample, to be $4\times {10}^8$ photons per joule of laser energy. This novel all-optical, compact, and efficient electron-$\gamma$ source is suitable for photonuclear studies and medical uses.