Table:
text: List of nuclear weapons tests
List of most powerful nuclear tests
List of most powerful nuclear tests
Date_GMT Yield_megatons Deployment Country Test_Site Name_or_Number
October 30, 1961 50 parachute air drop Soviet Union Novaya Zemlya Tsar Bomba , Test #130
December 24, 1962 24.2 air drop Soviet Union Novaya Zemlya Test #219
August 5, 1962 21.1 air drop Soviet Union Novaya Zemlya Test #147
September 27, 1962 20.0 air drop Soviet Union Novaya Zemlya Test #174
September 25, 1962 19.1 air drop Soviet Union Novaya Zemlya Test #173
February 28, 1954 15 ground USA Bikini Atoll Castle Bravo
May 4, 1954 13.5 barge USA Bikini Atoll Castle Yankee
October 23, 1961 12.5 air drop Soviet Union Novaya Zemlya Test #123

Question: What is the name of 15 yield under the list of nuclear weapons tests in the United States?