June 28, 2015 to July 2, 2015
JW Marriott Starr Pass Resort
Etc/GMT-7 timezone

The Role of Cryogenics in the U.S. Hydrogen Bomb Program and Vise Versa

Jun 30, 2015, 8:15 AM
Tucson Ballroom EF

Tucson Ballroom EF

Plenary CEC-02 - Large-Scale Systems, Facilities, and Testing C2PL - Tuesday CEC Plenary Session - sponsored by Cryomech, Inc.


Dr Ray Radebaugh (National Institute of Standards and Technology)


Research on the H-bomb (called the “super” during early work) began at a low level at Los Alamos National Laboratory during the early- to mid-1940s as part of the Manhattan Project. Theorist felt the thermonuclear reaction within liquid deuterium was the simplest and best understood at that time. On January 31, 1950, President Truman gave the order to pursue the H-bomb, which resulted in an arms race with the Soviet Union at a cost of trillions of dollars. Another outcome was the construction of the world’s largest hydrogen liquefier (320 L/hr) at that time, along with the establishment of the NBS Cryogenic Engineering Laboratory (CEL) in Boulder. A duplicate liquefier on Eniwetok Atoll in the Marshall Islands of the Pacific was used to liquefy deuterium gas generated from electrolysis of heavy water at NBS CEL and shipped to Eniwetok. The first full-scale test of thermonuclear fusion used a liquid deuterium secondary enclosed inside a thick steel shell containing the fission primary. Details of the massive cryogenic program, including declassified video clips, leading up to the test of this “wet” device will be discussed. The yield of 10.4 Mt in the November 1, 1952, Ivy Mike test was about 500 times that of the WWII fission bombs. During the next year and a half, lighter versions of the “wet” device were under development, but their tests were cancelled after the success of the first “dry” bomb that used lithium deuteride. Funding from the Atomic Energy Commission for further cryogenic research pertaining to weapons quickly evaporated, but the newly acquired expertise at NBS in liquid hydrogen and cryogenics in general was put to good use in the space program, which had just begun, and in some other classified programs. The first Cryogenic Engineering Conference held at NBS/Boulder in September, 1954, was organized because of the need to quickly spread the word about the cryogenic expertise available to new programs. Some of the significant cryogenic advances that came out of the H-bomb program will be discussed.

Primary author

Dr Ray Radebaugh (National Institute of Standards and Technology)

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