The First War of Physics (69 page)

After some ups and downs, the design of the first thermonuclear bomb was fixed in March 1952. This was the sequence of physical events. The fission primary would explode at the tip of a 20-foot long cylinder weighing
82 tons. X-rays from the fission explosion would be channelled down the cylinder and around the outside of the secondary device positioned along the cylinder’s long axis. A lining of polyethylene would be turned to plasma, radiating more X-rays towards the centre of the secondary, the radiation pressure collapsing and concentrating the cold, liquid deuterium it contained. Squeezing the deuterium from the outside in would implode a fission ‘sparkplug’ made of plutonium and suspended down the centre of the secondary. This would trigger a second fission explosion boosted by high-energy neutrons from fusion reactions. Squeezing the deuterium now also from the inside out and heating it with X-rays would trigger a series of nuclear fusion reactions. These reactions would all liberate nuclear energy but the greatest source of explosive force would come from high-energy neutron fissioning of U-238 nuclei from the uranium ‘pusher’ which would line the outside of the secondary device.

The bomb, designated Mike, was tested at Eniwetok Atoll on 1 November 1952, part of the Ivy test series. Its yield was 10.4 million tons of TNT equivalent, about 1,000 times more powerful than the Hiroshima atomic bomb. Within seconds of ignition it had produced a fireball that spread three miles in diameter. It vaporised the tiny island of Elugelab, leaving a circular crater more than a mile wide and 200 feet deep.

For what it was worth, America had re-established its technical lead in nuclear weapons.

Scorpions in a bottle

Stalin died on 5 March 1953 of a cerebral haemorrhage. Molotov later revealed in his memoirs that Beria claimed to have poisoned him, although the precise circumstances of Stalin’s death may never be known. Georgei Malenkov was appointed as chairman of the Council of Ministers. Beria himself was arrested by Marshal Zhukov on 26 June. Towards the end of July the Party Central Committee issued a letter declaring Beria a ‘bourgeois degenerate’ and detailing his horrific crimes. But it was not opprobrium over Beria’s reign of terror that had led to his arrest. As part of his strategy to seize power after Stalin’s death he had initiated a relaxation
of Soviet policy which had backfired in East Germany. He was arrested because he had gone too far and was judged a liability. He was executed on 23 December.

Stalin was gone but it was business as usual. On 12 August 1953 the Soviet Union tested RDS-6s, or Joe-4, a ‘layer cake’ thermonuclear device which made use of fusion in lithium deuteride to enhance the yield of a fission bomb. It yielded 400,000 tons. Vyacheslav Malyshev, who had taken over from Beria as head of the Soviet atomic programme, declared after the test that he had just received a call from Malenkov: ‘He congratulates everyone who helped build the hydrogen bomb – the scientists, the engineers, the workmen – on their wonderful success. Georgei Maximilianovich [Malenkov] requested me to congratulate and embrace Sakharov in particular for his exceptional contributions to the cause of peace.’

The nature and scale of nuclear weapons escalation was now set. In a speech to the Council on Foreign Relations in New York on 17 February 1953, Oppenheimer had made this comparison:

The trouble then is just this: During this period the atomic clock ticks faster and faster; we may anticipate a state of affairs in which two Great Powers will each be in a position to put an end to the civilisation and life of the other, though not without risking its own. We may be likened to two scorpions in a bottle, each capable of killing the other, but only at the risk of his own life.

Although the Soviet ‘layer cake’ was in many ways inferior to the two-stage Teller–Ulam design tested the previous November, the Soviet physicists were indeed not that far behind, at least in their understanding of the theory. Having pushed various ‘exotic’ variations on the design of RDS-6s, in early 1954 Sakharov abandoned these in favour of a two-stage radiation compression design – essentially the Teller-Ulam configuration – that had been developed independently by several theoreticians at Arzamas-16. In his memoirs Sakharov called it the ‘Third Idea’.

Meanwhile, with support from Lawrence, Teller had arm-twisted the AEC into setting up a second thermonuclear weapons laboratory, at a
cost of nearly $12 million, on the site of a former air base at Livermore in California. Teller’s popularity rating at Los Alamos fell to a new low as a bitter rivalry developed.

Despite this rivalry, the Livermore laboratory and Los Alamos combined their efforts in the Bravo test on Bikini, part of the Castle series, on 1 March 1954. Bravo was a much smaller lithium deuteride-fuelled thermonuclear device, weighing in at nearly twelve tons and therefore much easier to ‘weaponise’ than Mike. The rare Li-6 isotope had been enriched in the fuel from 7.5 to 40 per cent.

An error in the measurement of the rate of a nuclear reaction involving the dominant Li-7 isotope led the physicists to underestimate its potential yield. Bravo should have yielded five million tons. It actually yielded three times this figure; at fifteen million tons it was the largest nuclear weapon ever tested by the United States. Its fireball measured nearly four miles across as it vaporised three islands and threw radioactive debris over nearly 50,000 square miles, exposing the task force personnel thought to be at a safe distance out at sea and the crew of a Japanese fishing boat. The Japanese fishermen arrived at port suffering radiation sickness similar to the initial survivors of Hiroshima and Nagasaki. The inhabitants of the islands of Rongelap and Ailinginae had to be hastily evacuated.

The Soviet Union tested its first two-stage, lithium deuteride-fuelled, megaton-yield weapon on 22 November 1955. Designated RDS-37, and dropped from an aeroplane rather than triggered atop a tower, its theoretical yield was three megatons but it had deliberately been limited to little more than half this to reduce the risks from fallout. The Shockwave cracked the ceiling of the observation bunker, raining loose plaster on Zavenyagin’s head. It also collapsed a trench in which a platoon of soldiers was sheltering, killing one young soldier in his first year of service. There were further fatalities among the civilian population living close to the Semipalatinsk test site. Another collapsed shelter had killed a two-year-old girl.

‘For my part, I experienced a range of contradictory sentiments,’ Sakharov wrote, ‘perhaps chief among them a fear that this newly released force could slip out of control and lead to unimaginable disasters. The accident reports, and especially the deaths of the little girl and the soldier,
heightened my sense of foreboding. I did not hold myself personally responsible for their deaths, but I could not escape a feeling of complicity.’

The pattern of escalation was repeated again and again throughout the Cold War. In truth, the Soviets did catch up in terms of the science and technology, but they never did surpass the potential destructive force of the American nuclear arsenal. But this had long since ceased to be the point. The larger American scorpion carried the greater sting, but the Soviet scorpion’s smaller sting was still deadly. The American policy of ‘massive retaliation’ did not change the simple fact that in nuclear war destruction remained mutual, and assured.

The inexorable growth of the American nuclear arsenal simply increased the American military’s ability to ‘bounce rubble’.

In the matter of J. Robert Oppenheimer

Oppenheimer had used the position he had acquired on the world stage as the ‘father of the atom bomb’ to make political pronouncements and exert influence over American nuclear policy. But what some perceived to be clear-headed and reasoned arguments, others saw as misguided liberal sermonising. And although Oppenheimer retained the ability to charm, he had lost none of his character flaws. His casual arrogance, his thinlydisguised disdain for those he thought intellectually inferior or wrongheaded, and his acidic put-downs had helped create enemies where friends might have proved more useful.

Chief among his enemies was Lewis Strauss, who had resigned as AEC commissioner in protest over delays to the Super programme. When Eisenhower, elected as US President on 4 November 1952, appointed Strauss as chairman of the AEC in January 1953, Strauss began a campaign to discredit Oppenheimer and remove him completely from his position of influence. By this time Oppenheimer was no longer chairman of the GAC. He had stepped down in 1952, largely in frustration, but had been persuaded to continue as a consultant, extending his Q-clearance for at least another year.

Strauss had contributed to Eisenhower’s election campaign fund and now moved to sow seeds of doubt in the President’s mind regarding Oppenheimer’s fitness even for his lesser role as consultant. Strauss also encouraged William L. Borden, a young member of the Joint Committee on Atomic Energy
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and already deeply suspicious of Oppenheimer, to examine the evidence that had sat festering in Oppenheimer’s weighty FBI file for more than a decade. On 7 November 1953 Borden, on his ‘own personal initiative and responsibility’, wrote a letter to Hoover in which he asserted, ‘based upon years of study, of the available classified evidence, that more probably than not J. Robert Oppenheimer is an agent of the Soviet Union’. The letter went on to declare that: ‘[H]e has since acted under a Soviet directive in influencing United States military, atomic energy, intelligence and diplomatic policy.’

In truth, Borden had no new evidence on which to base his denunciation. The most serious allegation against Oppenheimer’s loyalty to America remained his attempted obfuscation regarding the ‘Chevalier incident’. This was an incident that had been examined several times in numerous security reviews and, while all who knew of it regarded it as very unfortunate, it had not previously been seen as sufficiently serious to deny security clearance. The real issue was the perceived loss of American technical leadership on the H-bomb, for which Oppenheimer was regarded as worthy of blame. Oppenheimer’s obstinacy, amplified by his extensive influence, was seen by Borden to be motivated not by rational scientific or moral judgements, but by directive from Moscow. There was absolutely no evidence for this.

Strauss knew he would get only one chance to bring Oppenheimer down and wanted to wait for precisely the right moment to spring his trap, but events forced his hand. Borden’s letter was forwarded to Eisenhower who, fearing that a failure to act would expose his administration to damaging allegations of incompetence by McCarthy, secretly suspended Oppenheimer’s security clearance on 3 December. Hoover had already
moved to divert McCarthy from the Oppenheimer case, concerned that the Wisconsin senator would bungle it.

Oppenheimer was told of the decision to suspend his clearance on 21 December. Two days later he requested a formal hearing so that he could clear his name.

This was to be a hearing of the AEC’s Personnel Security Board. As such it had no precedent and no formal basis in law and, as AEC chairman, Strauss was free to set it up in whatever way he saw fit. He proceeded to stack the deck as firmly and as unfairly against Oppenheimer as he could, through a series of manoeuvres worthy of the Soviet Politburo.

Strauss handpicked the members of the Security Board that would sit in judgement. He ensured that the members of this ‘jury’ had full access to all the evidence assembled by the FBI, which they reviewed in the presence of the prosecuting attorney, Roger Robb. Strauss had selected Robb on the strength of his reputation: he had the cross-examination skills of a Rottweiler.

Oppenheimer was once again under ‘technical surveillance’ by the FBI, meaning that his phones were tapped and his offices bugged. Strauss ensured that the surveillance continued throughout the hearing and that the prosecuting attorney had access to the results, including taped conversations between Oppenheimer and his defence attorney, Lloyd Garrison. In his turn, Garrison was denied access to the FBI evidence against his client. When the AEC finally relented and agreed to expedite his Q-clearance, he was told that this couldn’t be extended to the other members of the defence team. Garrison made a profound mistake, withdrawing the request for clearance in the belief that it would be impossible for the defence team to work together if only one member had access to the relevant information. By the time he changed his mind it was too late. Garrison never gained access to the FBI files and several times during the hearing the defence team was obliged to leave the room.

The hearing began on 12 April 1954, in room 2022 at the AEC’s headquarters, Building T-3 on the corner of Sixteenth and Constitution in Washington, DC. It began by reading into the record a list of charges levelled by AEC general manager Kenneth D. Nichols, Groves’ former aide
on the Manhattan Project, and Oppenheimer’s personal, lengthy, rebuttal. Two days later, Robb was relentlessly pursuing Oppenheimer on the circumstances surrounding the Chevalier incident.

‘Now let us get back to your interview with Colonel Pash. Did you tell Pash the truth about this thing?’ Robb asked.

‘No’, Oppenheimer answered.

‘You lied to him?’

‘Yes.’

Robb now probed the details of the story Oppenheimer had given Pash and Johnson that August day in Berkeley, nearly eleven years before. He asked if Oppenheimer had said that Chevalier, then unnamed, had approached three people.

‘Probably’, Oppenheimer replied.

‘Why did you do that, Doctor?’

‘Because I was an idiot.’

Robb later told a reporter that at this stage in the proceedings Oppenheimer was visibly struggling with his testimony, wringing his hands between his knees as he sat, under oath, in the witness-box. Robb proceeded to read from the transcript of the recorded conversation, advising Oppenheimer that ‘for your information, I might say we have a record of your voice’. The nature of Oppenheimer’s ‘cock and bull story’ was fully exposed. Robb forced him to admit that he had told ‘not one lie … but a whole fabrication and tissue of lies’.