| The TRIUMPF laser may allow making self-generated fields in a laser-plasma interaction at ultra-relativistic intensity (>1022 W/cm2). Recent simulations show that a laser pulse with an ultra-high peak intensity (5x1022 W/cm2) can generate an azimuthal megatesla-level magnetic field in a classically overcritical plasm, as illustrated in Figure 3.6[1]. The field is sustained by a strong longitudinal electron current driven by the laser field in relativistic transparent plasma. MT scale B-fields could be generated, comparable to the oscillating magnetic field of the intense laser itself This strong magnetic field stimulates emission of multi-MeV photons, producing a collimated beam of gamma-rays. The density of emitting electrons is significantly over-critical and, as a result, the density of photons would be significantly higher than what is typically observed in underdense plasmas. |
Figure 3.6: Simulation of an ultra-intense multi-PW pulse propagating through relativistically transparent overdense plasma generating magnetic fields of over 1 MegaTesla. |
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[1] D. J. Stark, T. Toncian and A. V. Arefiev “Enhanced Multi-MeV Photon Emission by a Laser-Driven Electron Beam in a Self-Generated Magnetic Field,” Phys. Rev. Lett. 116, 185003 (2016). https://doi.org/10.1103/PhysRevLett.116.185003