Deterministic model for the transport of energetic particles: Application in the electron radiotherapy

Efficient ion acceleration and dense electron–positron plasma creation in ultra-high intensity laser-solid interactions

“…Ultra-high intensity lasers accelerate ions over much shorter distances than conventional accelerators (microns compared to many meters) with potential applications in medical physics [1] as well as in fundamental physics [2]. Next generation lasers, such as those comprising the soon to be completed Extreme Light Infrastructure [3], could accelerate ions to GeV energies with 100% efficiency in principle [4,5].…”

Mapping the Damping Dynamics of Mega-Ampere Electron Pulses Inside a Solid

“…A major problem in understanding the physics arises due to the paucity of information on the characteristics of these fast electrons as they transit through the solid. From a practical viewpoint, the behavior of energetic electrons as they pass through a dense, hot solid is central to a multitude of applications of short-pulse laser-matter interaction [8,9], as the energy is transferred from the driving laser field to the secondary emissions through these electrons. Although hot-electron transport through solids has been studied [10][11][12][13], very little is known about the time the electrons spend inside a solid while dissipating their energy.…”

“…So far, most studies have used micron-thick targets and relied on optical transient emission from the rear side to diagnose hot-electron transport [11,23,24]. In relativistic laser-matter interaction, however, electron energies can be as high as a few MeV, with a stopping range of a few millimetres in a solid [9]. For thin targets, only a fraction of the hot-electron population with the stopping range matching the target thickness would contribute to the Cherenkov emission, while the higher energy electrons would escape the target.…”

“…The observed Cherenkov temporal evolution has three distinct features: a "rise," a "broad peak," and a "decay." The earliest photons we measure come from a few highestenergy electrons that propagate without losing much of their energy until the target rear, where they get scattered off nuclei at angles of ∼40°− 50° [9]. As these electrons travel at near-light speeds until target rear, the Cherenkov photons they generate are produced at time t 1 ≃ d=c with respect to t ¼ 0, d being the target thickness.…”

“…As seen from these simulations, the discrepancy between the lifetimes of superluminal electrons and the Cherenkov emission is due to the multiple scattering events the electrons undergo while getting damped [9,31], spreading them in the transverse direction. Cherenkov photons from these sources will need to traverse additional paths in order to reach the detector, yielding delays in the observed Cherenkov signal.…”