Observation of Gigawatt-Class THz Pulses from a Compact Laser-Driven Particle Accelerator
Gopal, A × Herzer, S Schmidt, A Singh, P Reinhard, A Ziegler, W Broemmel, D Karmakar, A Gibbon, Paul Dillner, U May, T Meyer, H-G Paulus, G. G #
American Physical Society
Physical Review Letters vol:111 issue:7
We report the observation of subpicosecond terahertz (T-ray) pulses with energies 460 micro-J from a laser-driven ion accelerator, thus rendering the peak power of the source higher even than that of state-of-the-art synchrotrons. Experiments were performed with intense laser pulses (up to 5 10^19 W/cm^2) to irradiate thin metal foil targets. Ion spectra measured simultaneously showed a square law dependence of the T-ray yield on particle number. Two-dimensional particle-in-cell simulations show the presence of transient currents at the target rear surface which could be responsible for the strong T-ray emission.