Particle density measurements in beam-confinement fusion systems

A system for determining the spatial distribution of particles in beam-confinement fusion systems has been developed. In particular, the method has been applied to the self-collider beam-confinement fusion system currently under development at the University of Florida. In this system, fusionable charged particles such as protons, deuterons, 3He+, and heavier species injected by an electrostatic accelerator describe rosette-shaped trajectories under the influence of strong axially and radially focusing magnetic fields. The purpose of this arrangement is to create a high density of particles traveling in orbits that collide at the center of the distribution, thus establishing a favorable environment for the occurrence of fusion reactions. Computer simulations of the trajectories of the particles in the double-focused field show that at any given time the density of the particles varies as the inverse square of the distance from the center of the reaction chamber. Verification of these simulations requires the measurement of particle distribution within the chamber. The method developed for this purpose is based on the production of characteristic X rays by materials when bombarded by energetic particles: If targets of different materials are placed at different points in the three-dimensional region in which the distribution of energetic particles is to be measured, the different energies of the emitted characteristic X rays indicate the locations at which the X rays were produced, and the intensity of the spectral lines indicates the charged-particle density at those locations