The inception of photoelectric scintillation detection commemorated after three decades

The modern photoelectric scintillation detector emerged just 30 years ago out of the rubble of World War II. Kallmann in Germany had the original idea of combining an organic fluor (naphthalene), which is transparent to its fluorescent light, with an electronmultiplier phototube for the detection of single scintillation evants. Hofstadter at Princeton discovered that the inorganic thallium-activated sodium iodide scintillator has superior gamma detection efficiency and a high photoelectric yield for gamma spectrometry.