Simulation imaging process of laser-induced multi-MeV photon emission

Abstract

A complete simulation chain for the laser-based generation of a microfocus-size gamma ray beam of multi-MeV energy range able to produce radiographic images has been developed. The major interactions needed to obtain such a beam are treated individually. Particle-in-cell is used to study the generation of the electron beam through laser wake-field acceleration (LWFA), and Geant4 is employed for the Bremsstrahlung photon emission and for testing the imaging capabilities of the generated gamma beam. The paper presents detailed discussions about the implementation of each simulation, along with the results obtained. The structure of the article walks through the LWFA of up to 100 MeV electron beam, followed by its attenuation through a tantalum foil generating a 300μm spot size photon beam, later used for imaging of a thick lead test-object, assessing a 100μm resolution, and confirming the simulated imaging setup suitability for non-destructive testing applications of thick high-density objects. An analysis of the quality control parameters for the generated image along with discussions of possible improvements is also included.