Range and light output measurements of trajectory images in a GAGG plate with different alpha particle energies

Abstract

An imaging method that utilizes a scintillator plate combined with a magnifying unit and a cooled electron multiplying charge-coupled device (EM-CCD) camera shows promise for obtaining high-resolution trajectory images. However, it is not yet clear whether the ranges of the trajectory images change with the energy of the alpha particles. Additionally, it remains unclear whether the intensity of the trajectory images is affected by the energy of the alpha particles. To address these questions in our trajectory imaging research, we conducted experiments to capture trajectory images of alpha particles with varying energy levels. To generate alpha particles with different energies, we modulated the energy using an americium-241 (Am-241) source covered with varying numbers of Mylar films. With this alpha source and imaging system, we successfully captured trajectory images with different alpha particle energies and were able to assess the ranges and intensities of these trajectories at various energy levels. The estimated ranges from the measured images with different alpha particle energies closely matched the results obtained through simulations. However, it's worth noting that the light output, as evaluated for the measured trajectory images, was slightly lower than the simulated results at lower energy levels probably due to the non-proportionality of the GAGG plate with respect to alpha particle energies.

A method for estimating the incident directions of alpha particles in 2-dimensional trajectory images in a GAGG plate

“…This improvement in spatial resolution can be attributed to the use of the finely polished GAGG plate, which has a smoother surface conducive to high-quality and high-resolution imaging. The energy resolution of the imaging system was ∼ 30% FWHM for ∼ 5MeV alpha particles [15].…”