QED-driven laser absorption

Abstract

Absorption covers the physical processes which convert intense photon flux into energetic particles when a high-power laser illuminates optically-thick matter. It underpins important petawatt-scale applications today, e.g., medical-quality proton beam production. However, development of ultrahigh-field applications has been hindered since no study so far has described absorption throughout the entire transition from the classical to the quantum electrodynamical (QED) regime of plasma physics. Here we present a model of absorption that holds over an unprecedented six orders-ofmagnitude in optical intensity and lays the groundwork for QED applications of laser-driven particle beams. We demonstrate 58% efficient γ-ray production at 1.8 × 10 25 W cm −2 and the creation of an anti-matter source achieving 4 × 10 24 positrons cm −3 , 10 6 × denser than of any known photonic scheme. These results will find applications in scaled laboratory probes of black hole and pulsar winds,γ-ray radiography for materials science and homeland security, and fundamental nuclear physics.

Efficient ion acceleration and dense electron-positron plasma creation in ultra-high intensity laser-solid interactions

“…( 1) and ( 2) require a prediction for the laser absorption caused by QED radiation losses. Several scaling laws for QED-mediated laser absorption have been discussed in the literature [47], for linear [48,49] and circular [4,50] laser polarization. In the simulation discussed above (and those discussed later) the laser absorption occurs almost entirely in the self-generated pair plasma.…”