The liquid deuterium fuel of Ivy Mike was impractical for a deployable weapon , and the next advance was to use a solid lithium deuteride fusion fuel instead . In 1954 this was tested in the " Castle Bravo " shot ( the device was code-named '' Shrimp '' ) , which had a yield of 15 megatons ( 2.5 times expected ) and is the largest U.S. bomb ever tested
Castle Bravo
Castle Bravo
Thermonuclear weapon