Lab-Astrophysics by Laser-Plasmas
By squeezing an enormous amount of energy into a tiny space, they can reproduce similar states to astrophysical phenomena, such as black hole radiation, gigantic gamma flares, core collapse and supernova explosion, matter-anti-matter mixture just after the big bang, genesis of cosmic magnetic fields, and so many others. The concentration of energy into a small space can be most efficiently achieved by focusing high power lasers. We theoretically study the next-generation lab-astrophysics based on exawatt and zettawatt lasers.
Radiation Reaction
Photon emission from a uniformly accelerated charge is among the most mysterious physical phenomena. Theories based on the Lorentz-Abraham-Dirac equation mostly conclude that a uniformly accelerated point charge cannot feel radiation reaction. Such a conclusion suggests that the origin of the photon energy is unclear. In this paper, we determine the self-force of a uniformly accelerated charged sphere using the Lorentz force equation, with an assumption that the sphere is Lorentz-contracted during the acceleration. For large acceleration, the calculated self-force converges to the radiation reaction (given by the Larmor formula) via a new factor γa, which describes an acceleration-dependent increase in the effective mass. This increased mass makes it harder to accelerate the particle (compared to a point-charge), which means more energy should be provided to the particle in order to get the expected acceleration. This extra energy can be interpreted as the origin of the photon energy.
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