A multi-material diagnosis method based on high-energy proton radiography

Diagnosis of fluids is extremely significant at high temperatures and high pressures. As an advanced imaging technique, high-energy proton radiography has great potential for application to the diagnosis of high-density fluids. In high-energy proton radiography, an angular collimator can control the proton flux and thus enable material diagnosis and reconstruction of density. In this paper, we propose a multi-material diagnostic method using angular collimators. The method is verified by reconstructing the density distribution from the proton flux obtained via theoretical calculations and numerical simulations. We simulate a 20 GeV proton imaging system using the Geant4 software toolkit and obtain the characteristic parameters of single-material objects. We design several concentric spherical objects to verify the method. We discuss its application to detonation tests. The results show that this method can determine the material and boundary information about each component of a multi-material object. Thus, it can be used to diagnose a mixed material and reconstruct densities in a detonation.