Multi-Frame Ion Pinhole Camera for Intense Ion Beam Transport and Focusing Experiments

摘要

We have developed a new ion pinhole camera to obtain energy density profiles of a focused multi-terawatt ion beam as a function of ion energy. Beam ions that are elastically scattered from a thin gold foil are imaged through six baffled pinholes onto six separate areas of a sheet of CR-39 nuclear track detector. Each of the areas is covered by an aluminum range filter and records an image with a different lower bound on the ion energy. Subtracting images with adjacent cutoff energies results in images with upper and lower bounds on the ion energy. Ion images are read from the CR-39 with VERA, a fully-automatic, image-processor-based nuclear-track-counting system. Images of the Particle Beam Fusion Accelerator-II (PBFA-II) proton beam have been obtained and show that the beam has been focused to achieve a horizontal FWHM of 5.7 mm and has delivered 18 kJcm sup 2 to a target. 4 refs., 6 figs. (ERA citation 13:029784)