Operation Castle
"Operation Castle" was intended to test lithium deuteride (LiD) as a thermonuclear fusion fuel. A solid at room temperature, LiD, if it worked, would be far more practical than the cryogenic liquid deuterium fuel in the Ivy Mike device. The same Teller-Ulam principle would be used as in the "Ivy Mike" so-called "Sausage" device, but the fusion reactions were different. "Ivy Mike" fused deuterium with deuterium, but the LiD devices would fuse deuterium with tritium. The tritium was produced during the explosion by irradiating the lithium with fast neutrons.