Relativistic Positron Creation Using Ultraintense Short Pulse Lasers

Abstract

We measure up to 2x10;{10} positrons per steradian ejected out the back of approximately mm thick gold targets when illuminated with short ( approximately 1 ps) ultraintense ( approximately 1x10;{20} W/cm;{2}) laser pulses. Positrons are produced predominately by the Bethe-Heitler process and have an effective temperature of 2-4 MeV, with the distribution peaking at 4-7 MeV. The angular distribution of the positrons is anisotropic. Modeling based on the measurements indicate the positron density to be approximately 10;{16} positrons/cm;{3}, the highest ever created in the laboratory.

On the origin of super-hot electrons from intense laser interactions with solid targets having moderate scale length preformed plasmas

“…However, experiments and computer PIC modeling typically produce electrons with energies that are significantly higher than the non-injection limit (which of course varies with the corresponding a 0 ) 7,14,19,30 . Indeed, our PIC modeling also predicts electrons with greater energy than this limit (U e,max 200M eV , see FIG.…”

“…Over the last decade, laser facilities with peak intensity I > 10 20 W cm 2 have enabled the study of a variety of exciting applications including ion acceleration 1-3 , x-ray generation 4,5 , and laboratory astrophysics 6,7 . These applications are driven by the relativistic electron beams generated by ultraintense short pulse lasers interacting with plasma and, in general, are enhanced by maximizing the hot electron current and energies.…”

Particle energization in 3D magnetic reconnection of relativistic pair plasmas

“…Magnetic reconnection of pair plasmas provides a unique opportunity to examine critically the fundamental reconnection physics due to the absence of Hall term, [3] which is generally thought to be the main mechanism for fast reconnection in electron-ion plasmas. Understanding of relativistic magnetic reconnection of pair plasmas will also provide useful physical insights for both new laboratory experiments of pair plasmas [4] and observations of the high energy Universe.…”

Exploring novel target structures for manipulating relativistic laser–plasma interaction

“…They can be applied to various aspects such as target normal sheath acceleration of ions [16][17][18][19][20][21] , x/γ -ray emission [22] and generation of MeV-positron beams [23] . Both the cut-off energy and the population can be manipulated by adjusting the length and spatial period of the well-organized structures.…”