Simulation of Coherent Terahertz Radiation from Relativistic Laser-Solid Interactions

Experiments to study the interaction between a high-intensity (>10¹⁸ W/cm²) laser and various solid targets have been performed at the University of Rochester Laboratory for Laser Energetics (LLE) lab aimed to generate terahertz (THz) radiation.  2D3V particle-in-cell (PIC) simulations have been performed at TAE Technologies, Inc (TAE) in support of the experiment.  The PIC simulations reproduce the experimentally observed THz characteristics as well as the electron energy spectrum.  Further, we shall report on the scaling of THz energy with laser intensity.  We shall also report on a more optimized scenario where a microplasma waveguide (MPW) is irradiated with a relativistic (a0>1) p-polarized sub-pico second laser, resulting in high-charge (10s nC) electron bunches with energies up to 100 MeV.  Lastly, we shall present THz radiation application to a novel pulsed polarimetry method to enable the measurement of internal magnetic fields in burning plasmas, with applications to TAE’s next generation field reversed configuration (FRC) device – Copernicus.