Laser Positron Accelerator - Novel Applications

A recently uncovered laser positron accelerator [Sahai, PRAB 21, 081301, 2018] for the first time makes possible production of ultra-short hundreds of MeV quasi-monoenergetic pico-Coulomb positron beams using currently available tens of Joule ultrafast CPA laser system. This groundbreaking model shows that acceleration of high-quality positron beam requires systematic understanding of the physics of interaction of laser-driven plasma-wave and laser-driven electromagnetic-shower. It takes advantage of the small source-size of the laser-driven electromagnetic-shower and the large tunable trapping potential of the laser-driven relativistic plasma-wave. While this technique has been verified using large-scale Particle-In-Cell computational modeling, its first experimental verification is still work in progress under the guidance of this model. In this work we explore certain important applications of hundreds of MeV positron beams. Although these applications hold the promise of paving new pathways they require positron beam characteristics which lay out major future challenges for the above model and demand new breakthroughs. These applications however put forth a strong case for positron beam production by ultrafast CPA laser-driven as uncovered by the above novel model.