Creating QED Photon Jets with Present-Day Lasers

Abstract

Large-scale, relativistic particle-in-cell simulations with quantum electrodynamics (QED) models show that high energy (1< Eγ < ∼ 75 MeV) QED photon jets with a flux of 10 12 sr −1 can be created with present-day lasers and planar, unstructured targets. This process involves a selfforming channel in the target in response to a laser pulse focused tightly (f number unity) onto the target surface. We show the self-formation of a channel to be robust to experimentally motivated variations in preplasma, angle of incidence, and laser stability, and present in simulations using historical shot data from the Texas Petawatt. We estimate that a detectable photon flux in the 10s of MeV range will require about 60 J in a 150 fs pulse.

Laser-driven neutron source from high temperature D-D fusion reactions

“…For a given laser intensity and target density, a well-defined range of target thickness optimizes transfer of laser energy into the target plasma [36]. Targets that are too thin (hundreds of nanometers as in the case of plastic foils) expand after ionization, significiantly decreasing the ion density and have a limited reaction volume, leading to a reduced neutron yield.…”