Abstract
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Objectives: For the development of new radio-compounds for targeting alpha radionuclide therapy, high resolution, low background alpha particle imaging system is desired. For this purpose we developed a new alpha particle imaging system with background rejection capability.
Methods: We used a Gd3(GaAl)5O12:Ce(GGAG) plate for the scintillator which is an excellent material for the development of an event-by-event-based radiation imaging detector when it was combined with a position sensitive photomultiplier (PSPMT). With the developed GGAG imaging detector, we found that the decay times for alpha particles and gamma photons or beta particles were different. These characteristics are advantageous for developing an imaging detector for the simultaneous imaging and separating the different types of radiations using pulse shape discrimination.
Results: The spatial resolution of the imaging system for alpha particles was better than 0.5mm FWHM. With the developed system, energy and pulse shape spectra for the different types of radiations could be measured. We obtained clearly separated images for alpha particles and gamma photons or beta particles using pulse shape discrimination. We could obtain high resolution alpha particle distribution images of the slices of rat administered Astatine-211.
Conclusions: We conclude that the developed alpha particle imaging system with background rejection capability is promising for alpha autoradiography.