Multi-stage scheme for nonlinear Breit-Wheeler pair-production utilising ultra-intense laser-solid interactions

TY - JOUR

T1 - Multi-stage scheme for nonlinear Breit-Wheeler pair-production utilising ultra-intense laser-solid interactions

AU - Duff, M. J.

AU - Capdessus, R.

AU - Ridgers, C. P.

AU - McKenna, P.

N1 - © 2019, IOP Publishing Ltd. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy.

PY - 2019/7/23

Y1 - 2019/7/23

N2 - Multi-petawatt (PW) lasers enable intensities exceeding 1023 W cm-2, at which point quantum electrodynamics (QED) processes, such as electron-positron pair-production via the nonlinear Breit-Wheeler process, will play a significant role in laser-plasma interactions. Using 2D QED-particle-in-cell simulations, we present a two-stage scheme in which nonlinear pair-production is induced via an ultra-intense laser-solid interaction. The first stage is the generation of a γ-ray beam, through the interaction of an ultra-intense laser pulse with a thick target, whose features are found to be strongly dependent on collective plasma effects. This compact, high energy γ-ray beam (characterised by a divergence half-angle ∼10° and average photon energy ∼10 MeV) then interacts with two counter-propagating laser pulses. By varying the laser polarisation and angle of incidence, we show that in the case of two circularly polarised laser pulses propagating at an angle equal to the divergence half-angle of the γ-ray beam, the produced positron distribution is highly anisotropic compared to the case of a standard head-on collision.

AB - Multi-petawatt (PW) lasers enable intensities exceeding 1023 W cm-2, at which point quantum electrodynamics (QED) processes, such as electron-positron pair-production via the nonlinear Breit-Wheeler process, will play a significant role in laser-plasma interactions. Using 2D QED-particle-in-cell simulations, we present a two-stage scheme in which nonlinear pair-production is induced via an ultra-intense laser-solid interaction. The first stage is the generation of a γ-ray beam, through the interaction of an ultra-intense laser pulse with a thick target, whose features are found to be strongly dependent on collective plasma effects. This compact, high energy γ-ray beam (characterised by a divergence half-angle ∼10° and average photon energy ∼10 MeV) then interacts with two counter-propagating laser pulses. By varying the laser polarisation and angle of incidence, we show that in the case of two circularly polarised laser pulses propagating at an angle equal to the divergence half-angle of the γ-ray beam, the produced positron distribution is highly anisotropic compared to the case of a standard head-on collision.

KW - nonlinear Breit-Wheeler process

KW - Pair-production

KW - ultra-intense laser-plasma interaction

UR - http://www.scopus.com/inward/record.url?scp=85072064137&partnerID=8YFLogxK

U2 - 10.1088/1361-6587/ab2ea6

DO - 10.1088/1361-6587/ab2ea6

M3 - Article

AN - SCOPUS:85072064137

SN - 0741-3335

VL - 61

JO - Plasma Physics and Controlled Fusion

JF - Plasma Physics and Controlled Fusion

IS - 9

M1 - 094001

ER -