How is californium-252 used in neutron-activation analysis and neutron radiography?

Californium-252 is a highly effective, intense source of neutrons because approximately 3 percent of its decay occurs through spontaneous fission.12

In these specialized applications, it functions as follows:

• Neutron-activation analysis: The isotope provides a reliable flux of neutrons used to identify and quantify elements within a sample. This process is utilized in practical fields such as mineral prospecting and the monitoring of oil wells.2
• Neutron radiography: Similar to X-ray imaging, this technique uses the neutron beam emitted by californium-252 to create images of the internal structure of objects. Because neutrons interact with matter differently than X-rays, this method is particularly useful for inspecting materials that are otherwise difficult to visualize.2

Beyond these uses, the isotope is employed in airport security detectors to identify nitrogenous materials like explosives and serves as a medical tool for irradiating tumors that do not respond well to traditional gamma-ray therapy. Its primary industrial role remains its use as a start-up source for calibrating nuclear reactor instrumentation.2