The device was called '' ' SHRIMP ' '' and had the same basic configuration ( radiation implosion ) as the '' Ivy Mike '' wet device , except with a different type of fusion fuel . '' SHRIMP '' used lithium deuteride ( LiD ) , which is solid at room temperature ; '' Ivy Mike '' used cryogenic liquid deuterium ( D2 ) , which required elaborate cooling equipment . '' Castle Bravo '' was the first test by the United States of a practical deliverable fusion bomb , even though the TX-21 as proof-tested in the Bravo event was not weaponized . The successful test rendered obsolete the cryogenic design used by '' Ivy Mike '' and its weaponized derivative , the '' JUGHEAD '' , which was slated to be tested as the initial '' Castle Yankee '' . It also used a 7075 aluminium 9.5 cm thick ballistic case . Aluminium was used to drastically reduce bomb 's weight and simultaneously provided sufficient radiation confinement time to raise yield , a departure from the heavy stainless steel casing ( 304L or MIM 316L ) employed by contemporary weapon-projects
Ivy Mike
Ivy Mike
Castle Bravo