Enhanced electron–positron pair production by ultra intense laser irradiating a compound target

Abstract

High-energy-density electron-positron pairs play an increasingly important role in many potential applications. Here, we propose a scheme for enhanced positron production by an ultra intense laser irradiating a gas-Al compound target via the multi-photon Breit-Wheeler (BW) process. The laser pulse first ionizes the gas and interacts with a near-critical-density plasma, forming an electron bubble behind the laser pulse. A great deal of electrons are trapped and accelerated in the bubble, while the laser front hole-bores the Al target and deforms its front surface. A part of the laser wave is thus reflected by the inner curved target surface and collides with the accelerated electron bunch. Finally, a large number of γ photons are emitted in the forward direction via the Compton back-scattering process and the BW process is initiated. Dense electron-positron pairs are produced with a maximum density of × 6.02 10 27 m −3 . Simulation results show that the positron generation is greatly enhanced in the compound target, where the positron yield is two orders of magnitude greater than that in only the solid slab case. The influences of the laser intensity, gas density and length on the positron beam quality are also discussed, which demonstrates the feasibility of the scheme in practice.

Highly efficient laser-driven Compton gamma-ray source

“…On the other hand, thanks to the spatiotemporal self-focusing process enabled by plasma lens in our scheme, one can initially employ a not-so-intense laser pulse with a large beam radius that is much easier to achieve in practice. In this sense, this scheme is also different from the previous works where a tightly focused laser pulse with a very large intensity and a rather small beam radius is assumed [49,50], which is, however, quite challenging in experiments for petawatt lasers.…”

Quantum electrodynamics experiments with colliding petawatt laser pulses

“…(Courtesy X-L. Zhu and T-P. Yu. ) pairs and very high laser energy conversion efficiency to hard Gamma photons [11][12][13][14][15][16][17][18][19][20] .…”

“…A third scheme [13][14][15] simulates the second colliding PWclass laser pulse being replaced by the reflection of the first pulse plasma mirror. The first laser pulse travelling through the plasma is reflected by the mirror and interacts with the high energy electron bunch generating copious Gamma photons and positrons.…”

“…Theoretical studies of colliding laser beams in solid and near-critical plasmas at intensities of 10 22 W/cm 2 , 10 23 W/cm 2 and even 10 24 W/cm 2 predict efficient conversion of laser energy into dense electron-positron pairs and bursts of energetic Gamma rays [11][12][13][14][15][16][17][18][19][20] .…”

High density γ-ray emission and dense positron production via multi-laser driven circular target

“…Another way is to change the plasma target configuration, such as one or multiple laser interaction with near-critical-density plasma [28][29][30][31], solid Al target [32][33][34] or gas plasma [35,36]. Among them, laser wakefield acceleration [37] and laser ponderomotive acceleration [38,39] are generally used to enhance electron acceleration and constraint.…”