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Thought for the Day…

• “It is still an unending source of surprise to me to see how a few scribbles on a blackboard could change the course of human affairs.” – Stanislaw Ulam, Polish mathematician and ‘co-

inventor’ of the US hydrogen bomb

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The Race to Build the ‘Super’

• Consider the hydrogen bomb on a number of levels such as…

• Consider the broader idea of how the H-bomb represented quest for a technological solution to a complex problem.

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What are the Effects of a Nuclear Explosion?

• Blast effects –

• Thermal radiation – 35% of the energy,

• Direct nuclear radiation

• Fallout – Long term effects

• Electromagnetic Pulse

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Consider the explosion of a nuclear device (150KT) over Manhattan

1 second

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4 seconds

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6 Seconds

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10 seconds

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16 seconds

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Distance fromground zero (mi.)

Population Fatalities Injuries Uninjured

0 - 0.4 75,000 75,000 0 0

0.4 - 1.0 400,000 300,000 100,000 0

1.0 - 1.5 500,000 220,000 220,000 60,000

1.5 - 2.5 1,500,000 235,000 525,000 740,000

2.5 - 4.0 500,000 0 30,000 470,000

Totals 2,975,000 830,000 875,000 1,270,000

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How a Hydrogen Bomb Works

• Unlike fission weapons which get their energy from the disintegration of elements like uranium and plutonium, the hydrogen bomb is a fusion weapon. The explosive energy comes from the joining together of light elements like hydrogen and lithium.

• Fusion is what powers the sun and other stars…

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Hans A. Bethe

• German physicist; Ph.D. in 1928; Nobel in 1968.

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• Nuclear energy can also be released by fusion of two light elements (elements with low atomic numbers).

• In H-bomb, two isotopes of hydrogen, deuterium and tritium are fused to form a nucleus of helium and a neutron.

• This fusion releases a great deal of energy.

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• Unlike nuclear fission, there is no limit on the amount of the fusion that can occur (i.e. bombs can be made as big as desired)

• The ingredients are cheap and plentiful.

• Plus – U-238 is usually the material used in various parts of the bomb's design to supply additional neutrons for the fusion process. This also produces a very high level of radioactive fallout.

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Nuclear Fusion

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The Technical Problem

• The question facing designers was “How do you build a bomb that will maintain the high temperatures and high pressures required for thermonuclear reactions to occur?”

• This became one of the focal points of work for scientists working on the H-bomb.

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The Life and Times of Edward Teller

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Early History of the H-bomb

• Idea for a fusion bomb first proposed by Teller in 1942 and worked on by Bethe, Teller, et al. at Los Alamos.

• Work at Los Alamos, to Teller’s disappointment, focused on fission weapons for the war.

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1946, Los Alamos“Super” Conference

• April 1946, about 30 scientists attend top secret meeting

• Teller describes his “classical” Super

• Klaus Fuch (Soviet spy) also in attendance

• Teller’s design proved unworkable by 1950

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Initial Efforts to Design the ‘Super’

• Ex: Teller’s “tube design”

• See article by Bethe for lots more detail

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The General Advisory Committee (GAC) to the Atomic Energy Commission

• 1949; GAC advised the AEC on matters of science and policy

• Group of several high-powered scientists.– Oppenheimer (chair)– Lee DuBridge (president, Caltech)– Enrico Fermi (Nobel)– Isidor Rabi (Nobel)– James Conant (president, Harvard)

• “…over my dead body”

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The GAC Report

• Group meets Oct. 28-29, 1949

• Issues a majority and minority opinion– Majority (Oppenheimer, DuBridge, Conant, et al.)

• US should not pursue the Super under any circumstances. It is a “weapon of genocide” which has no military value and would turn world opinion against the US. The US can and will have adequate number of fission bombs so as not to need the Super.

• Conant: “This whole discussion makes me feel I was seeing the same film, and a punk one, for the second time.”

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• Minority (Rabi and Fermi)– It is “necessarily an evil thing in any light” which

“cannot be justified on any ethical ground which gives a human being a certain individuality and dignity.”

– However – US should not unilaterally commit to not building it, but such a decision should be conditional on Soviet renunciation of future development.

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Summary so far…

• H-bomb has practically unlimited explosive potential. Requires an atomic bomb (!) to set it off and ignite the fusion reaction.

• Challenge to the weaponeers was how to do this.

• H-bomb decision divisive among scientists.

• GAC report recommends against ‘Super’

• Report goes ‘up’ to the AEC commissioners

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Enter Lewis L. Strauss

• 1896-1974; former shoe salesman turned millionaire banker and atomic enthusiast; played a pivotal role in shaping US nuclear policy.

• Member of AEC Commission, close connections with Truman and (later) Eisenhower.

• Advocates crash program to build H-bomb.

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Strauss Lobbies Truman for H-Bomb

• Strauss to Truman, Nov. 25, 1949– “…I believe it unwise to renounce unilaterally any

weapon which the enemy can reasonably be expected to possess.”

– Why? Russians are probably working on it (true); there is at least a 50-50 chance of success (probably true); Russians are atheists and have no moral qualms (??!); H-bomb can be used as a tactical weapon against deployed armies (false!).

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Other Voices

• David Lilienthal (AEC)

• Louis Johnson (Sec. Defense)

• Dean Acheson (Sec. State)

• Scientists and military leaders…

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• David Lilienthal, diary entry, March 1958– “E.O Lawrence, Luiz Alvarez, Edward Teller –

Madison Avenue-type scientists. Scientists in gray flannel suits.”

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Truman’s Decision to Build the ‘Super’

• January 31, 1950

• Context?– Soviet A-bomb– Alger Hiss – Klaus Fuchs – Korean War

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Truman Speaks

• January 31, 1950:• “I have directed the Atomic Energy Commission to

continue work on all forms of atomic weapons, including the so-called hydrogen or super bomb.”

• Surprisingly little concerted public outcry…most supported the idea (while still paradoxically hoping for some form of international arms control.

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Is there a pattern here?

• Fear and crisis…reaction?

• Continued focus on secrecy, exclusion, and monopoly, only now with regard to a new weapon.

• Continued belief that the U.S. would retain the edge.

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Errors of Judgment?

• What security and advantages did nuclear weapons bring?

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A New Weapons Laboratory

• Lawrence Livermore National Laboratory founded in 1952 about 45 miles from Berkeley.

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Scientists and the H-bomb Debate

• The H-bomb controversy was incredibly divisive for the American science community along the Teller/Lawrence – Oppenheimer/Conant axis.

• Differences between the H-bomb/A-bomb decision? Similarities?

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• The H-bomb fight became an important part of the 1954 decision to revoke Oppenheimer’s security clearance.

• The debate continues to raise important historical questions…

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H-Bomb Efforts in Russia

• Andrei Sakharov, 1921-1989.

• Soviet physicist, bomb designer, and (later) human rights activist.

• Son of a physicist; spent WW2 working in a munitions factory; turned down nuclear bomb work two times: “The third time nobody asked me.”

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Sakharov’s Sloika

• Sakharov “recruited” in spring 1950; a few months later he proposed a bomb design called the sloika – Russian for “layer cake.”

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Meanwhile, in the U.S. – Edward Teller and Stanislaw Ulam’s

Breakthrough

• Stanislaw Ulam, Polish-born mathematician; worked on Manhattan Project; returned to Los Alamos.

• March 1951 – Teller and Ulam develop idea of radiation-implosion.

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• Their plan? Use the radiation from the fission primary to compress and ignite the fusion secondary.

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The GEORGE Test

• May 1951

• Small capsule of hydrogen fuel placed next to an ‘ordinary’ atomic bomb.

• 25 kilotons

• Shows that Teller-Ulam idea should work…

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The MIKE Test

• November 1, 1952 – Large-scale physics experiment to test whether a hydrogen device (as opposed to an actual bomb) would work.

• Device (‘the sausage’) itself was 7’ x 20’ and weighed some 82 tons…hardly a weapon (yet).

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10 megatons with a fireball 3 miles in diameter. Cloud rose over 50 miles high.

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E. Teller: “It’s a boy.”

2 miles wide; ½ mile deep

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First Test of Soviet H-Bomb Device

• Less than a year after MIKE test…August 12, 1953…Sakharov’s Sloika” is tested

• Smaller in yield than MIKE but also small enough to be carried by a bomber (unlike MIKE).

• First full-fledged USSR thermonuclear test in 1955 – arms race now appears even.

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Largest Nuclear Test to Date

• Soviet 58 megaton explosion; October 30, 1961.

• Explosion visible over 400 miles away.

• Could cause 3rd degree burns up to 50 miles away.

• 100 Mt device designed; not tested.

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BRAVO and the Lucky Dragon

• The Bravo test – March 1, 1954 – 15 megatons (1000 times more powerful than Hiroshima bomb).

• Largest US test ever

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• Massive amounts of fallout created.

• Besides affecting islanders, the Japanese fishing vessel Daigo Fukuryu Maru (Lucky Dragon) was also heavily contaminated, with the 23 crewmen exposed (one later died).

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Fallout from Bravo Test

• Eisenhower very concerned that the world would think America was “skunks, saber-rattlers, and warmongers”

• Public fears over testing

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Epilogue: Are Technological Solutions the Answer?

• Hydrogen bomb

• Missile defense program

• Other areas of life…energy policy for example. Build hydrogen-cell cars or conserve gas? Health…eat less or liposuction?

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According to one observer…

• “The body of a bird was seen, but no living animals and only the stumps of vegetation. Among the specimens collected were fish which seemed to have been burned. On each of these fish, the skin was missing from one side, as if…the animal had been dropped into a hot pan.”

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• The first page of a memo by Zeldovich and Sakharov of 14 January 1954, describing the idea of AO - “Atomnoe Obzhatie” (atomic compression). 

• Translation:

“Top Secret. Special dossier. To Comrade Khariton. About using the gadget for implosion of the supergadget RDS-6s. This report presents a preliminary schematic of a device for the AO of the supergadget and calculations evaluating its performance.”