State-of-the-art Petawatt laser facilities  routinely generate multi-GeV electron beams [2,3] by laser wakefield acceleration and are envisioned to study fundamental QED processes in near future . Laser pulses with intensities over 1022 W/cm2 can be used to investigate nonlinear QED effects by colliding against counter-propagating high energy electron beams [5,6], and produce copious amounts of high energy photons and electron-positron pairs. These sources will be of great importance in their applications in broad areas of physics, as well as for understanding QED in strong background fields.
In this work, we examine the directionality of positrons and electrons produced from the pair creation process during laser-electron collisions. We numerically investigate the pair creation processes in collisions where a laser pulse with intensity I > 1022 W/cm2 scatters off a multi-GeV electron beam. The simulations are performed using the 3D particle-in-cell code EPOCH . We observed that the pulse shape, intensity, and polarization have effects on the phase-space distributions of pairs produced from Breit-Wheeler and Trident processes . We noticed that a significant number of pairs is expelled from the center of the laser pulse, following the polarization direction. Additionally, a small number of particles reverse the direction of its longitudinal momentum, propagating in the opposite direction of the incident electron beam. The results obtained in this work can provide crucial information on planning and detection of electron-positron pairs in collision experiments performed at multi-petawatt laser facilities.
- J. H. Sung et al., “4.2 PW, 20 fs Ti:sapphire laser at 0.1 Hz”, Opt. Lett. 42, 2058 (2017)
- H.T. Kim et al., “Stable multi-GeV electron accelerator driven by waveform-controlled PW laser pulses”, Sci. Rep. 7, 10203 (2017)
- A. J. Gonsalves et al., “Petawatt laser guiding and Electron Beam Acceleration to 8 GeV in a Laser-Heated Capillary Discharge Waveguide”, Phys. Rev. Lett. 122, 084801 (2019)
- A. DiPiazza et al., “Extremely high-intensity laser interactions with fundamental quantum systems”, Rev. Mod. Phys. 84, 1177
- J. M. Cole et al., “Experimental Evidence of Radiation Reaction in the Collision of a High-Intensity Laser Pulse with a Laser-Wakefield Accelerated Electron Beam”, Phys. Rev. X 8, 011020 (2018)
- K. Poder et al., “Experimental Signatures of the Quantum Nature of Radiation Reaction in the Field of an Ultraintense Laser”, Phys. Rev. X 8, 031004 (2018)
- T. D. Arber et al, “Contemporary particle-in-cell approach to laser-plasma modelling”, Plasma Phys. Control. Fusion 57, 113001 (2015)
- C.I Hojbota, “Effect of the temporal laser pulse asymmetry on pair production processes during intense laser-electron scattering”, Plasma Phys. Control. Fusion 60, 064004 (2018)
|Working group||Theory and computation|