Anomalous lepton acceleration in the radiation reaction dominated reflection regime

Area of Science:

• Plasma physics
• High-energy particle physics
• Laser-matter interactions

Background:

• Radiation reaction is expected to cause energy loss in relativistic electrons interacting with intense lasers.
• Previous studies focused on energy dissipation rather than particle acceleration in such scenarios.

Purpose of the Study:

• To investigate the counterintuitive energy gain of leptons under specific laser-electron interactions.
• To demonstrate a novel mechanism for generating and accelerating positrons to multi-GeV energies.

Main Methods:

• Utilizing three-dimensional particle-in-cell simulations.
• Modeling the interaction of ultraintense laser pulses with counterpropagating electrons.

Main Results:

• Observed reflected leptons (electrons and positrons) gaining significant energy.
• Demonstrated the generation of quasimonoenergetic positrons with multi-GeV energies.
• Achieved high number conversion efficiency for positron creation and acceleration.

Conclusions:

• A novel regime of lepton acceleration via laser-induced reflection and asymmetric field acceleration has been identified.
• This mechanism offers a single-stage solution for positron creation and acceleration using multipetawatt lasers.
• The findings have implications for understanding astrophysical phenomena, including the origin of ultrahigh-energy cosmic rays.