The First War of Physics (37 page)

Kistiakowsky took charge of a division consisting of about a dozen or so scientists, many of whom had been close colleagues of Neddermeyer’s. Within a few months the division had grown to 600, including 400 army physicists and engineers recruited to a Special Engineering Detachment (SED). The SEDs were enlisted personnel, many college-educated and some with Ph.D.s, ordered by the army to work at Los Alamos.

Among them was David Greenglass, a machinist assigned to Kistiakowsky’s division.

A problem underestimated

Igor Kurchatov was by nature a patient man, with a temperament well suited to managing a fundamentally important, large-scale scientific programme. However, by September 1944 his patience had worn thin.

Kurchatov had gathered around him a group of talented scientists to support the Soviet bomb programme. This group included Yuli Khariton, who had gained his Ph.D. in Cambridge in 1928 and who had studied explosives at the Institute for Chemical Physics in Leningrad. Before the war, Khariton had worked with Yakov Zeldovich on the theory of nuclear chain reactions. Also included in the group were Flerov, Issak Kikoin, Abram Alikhanov and Aleksandr Leipunskii, all graduates of the Leningrad Polytechnical Institute. Kurchatov’s brother Boris joined the group in the middle of 1943.

A new, secret laboratory had been established at the Seismological Institute in Moscow under the overall control of Mikhail Pervukhin, People’s Commissar of the Chemical Industry. To disguise its purpose, it was called simply Laboratory No. 2. As more and more scientists joined the programme, the laboratory expanded into adjacent premises before relocating in April 1944 to new buildings in the north-west of Moscow, near the Moscow River.

Kurchatov now established his programme along familiar lines. He took for himself the responsibility of designing and building the Soviet
Union’s first nuclear reactor, eventually fixing on a uranium–graphite pile with a lattice configuration.
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He was well aware that his biggest headache was going to be the lack of sources of uranium for the pile. He estimated that he needed about 60 tons, compared to the one to two tons available to him in 1943. Surveys of potential uranium deposits in Central Asia had suggested that a little over ten tons could be available by early 1944, implying that it would take five to ten years to acquire sufficient uranium for a nuclear reactor. The People’s Commissariat of Non-ferrous Metallurgy had been asked to find over 100 tons of uranium ‘as soon as possible’, which, against the urgent demands of the war against Germany, implied the lowest priority.

Without a reactor there could be no plutonium. Kurchatov asked that his team establish a cyclotron at Laboratory No. 2 as a matter of urgency. This could be assembled from the component parts of the Fiztekh cyclotron, which had become somewhat scattered and some of which were now located dangerously close to the front line. The cyclotron was needed to generate minute quantities of plutonium with which to perform critical physical measurements.

Kikoin took charge of the effort to identify methods for the large-scale separation of U-235. This, again, was work that was obviously contingent on Kurchatov’s ability to acquire sufficient quantities of natural uranium. Kikoin first examined centrifuge techniques, before moving on to gaseous diffusion. Thermal diffusion was also studied. In 1944, Lev Artsimovich joined Laboratory No. 2 to work on electromagnetic separation.

There remained the matter of bomb design. Kurchatov had known Khariton for nearly twenty years and, as the Soviet programme got under way, he asked Khariton to lead the design effort. Khariton was initially reluctant to abandon his work on anti-tank weapons, but Kurchatov was ultimately persuasive. Without quantities of materials sufficient for experimental study, however, Khariton could make little progress. He began some basic experiments to investigate the gun method.

The cyclotron became operational on 25 September 1944. Kurchatov and the cyclotron team celebrated this success with champagne. But any feeling of elation that Kurchatov felt was quickly overtaken by a strong sense of frustration. From the intelligence materials on ENORMOZ that he had seen, it was obvious that the Americans had embarked on a major project. The Soviet programme, by contrast, was severely hampered by the lack of materials. Without sufficient uranium, all they could do was theorise and carry out experiments that nagged at the very edges of the problems they needed to solve. A few days later, Kurchatov poured his exasperation into a letter to Beria:

But in our country, in spite of great progress in developing this work on uranium in 1943–1944, the state of affairs remains completely unsatisfactory. The situation with raw materials and questions of separation is particularly bad. The research at Laboratory No. 2 lacks an adequate material-technical base. Research at many organisations that are cooperating with us is not developing as it should because of the lack of unified leadership, and because the significance of the problem is underestimated in these organisations.

Near the edge of mortal crimes

Bohr’s attempts at atomic diplomacy had broken on the rocks of Churchill’s misplaced faith in secrets. But his arguments had persuaded many in Churchill’s inner circle, including Cherwell and Anderson. Bohr returned to Washington on 16 June 1944 and reported on his failed meeting with Churchill to Frankfurter a few days later. Frankfurter advised Roosevelt. Despite Bohr’s lack of success, Roosevelt continued to make encouraging noises and invited Bohr to discuss the issues directly with him.

Bohr first summarised his views in a short memorandum, which spoke of ‘forestalling a fateful competition about the formidable weapon’. Father and son worked on the memorandum as Washington steamed in a summer
heatwave. Aage typed the various drafts as his father wrestled with the precision of his language, while darning socks and sewing buttons. Bohr met with Roosevelt on 26 August.

This was a very different meeting. It lasted for more than an hour. Unlike Churchill, who was grumpy and appeared to have taken an instant dislike to Bohr, Roosevelt was cordial and found him interesting. Most importantly, Roosevelt found Bohr’s arguments persuasive. According to Aage Bohr:

Roosevelt agreed that an approach to the Soviet Union of the kind suggested must be tried, and said that he had the best hopes that such a step would achieve a favourable result. In his opinion Stalin was enough of a realist to understand the revolutionary importance of this scientific and technical advance and the consequences it implied.

The meeting concluded on a positive note. Bohr summarised the main points of their discussion in a letter to Roosevelt which reached him the day before he was due to depart for another meeting with Churchill in Quebec.

Bohr had grounds for optimism, but had not counted on Churchill’s wilfulness and the extent of his influence over the American President. At the end of the Quebec conference, Roosevelt and Churchill adjourned to Roosevelt’s private estate in the Hudson Valley at Hyde Park, New York. At this meeting Churchill moved to stomp on any attempt to reveal the existence of the bomb programme to the Soviet Union, or indeed to anyone – friend or foe – outside the terms of the Quebec agreement. In a secret aide-mémoire drafted, it would seem, largely by Churchill at the end of their meeting, the two leaders agreed to maintain the utmost secrecy. They acknowledged that: ‘When a “bomb” is finally available, it might perhaps, after mature consideration, be used against the Japanese, who should be warned that this bombardment will be repeated until they surrender.’

Churchill reserved particular ire for Bohr: ‘Enquiries should be made regarding the activities of Professor Bohr and steps taken to ensure that he is responsible for no leakage of information particularly to the Russians.’

At issue was a letter Bohr had received from the Soviet physicist Peter Kapitza via the Soviet embassy in London in April that year. In this letter, dated 28 October 1943, Kapitza had invited Bohr to the Soviet Union, using veiled language that could be interpreted as an invitation to collaborate on the development of atomic weapons.
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Bohr had sent a non-committal reply, which he had been sure to send first to the SIS for approval. He had handled the approach carefully and correctly.

But Churchill sensed treachery. To his mind, Bohr was in close correspondence with a Russian professor, an old friend to whom he had written and might be writing still. In a memo to Cherwell written the day after his Hyde Park meeting with Roosevelt, Churchill went even further: ‘It seems to me Bohr ought to be confined or at any rate made to see that he is very near the edge of mortal crimes.’

Churchill could not understand the complementarity of the atomic bomb. Roosevelt may have had his own reasons for acquiescing to Churchill’s views. Both may have chosen to fix on doubts about Bohr’s trustworthiness as the world’s first atomic diplomat as a way of ducking the issues that Bohr was trying to raise. In any event, despite Bohr’s best endeavours, the prospects for a post-war nuclear arms race had now been greatly enhanced.

Cherwell and Anderson leapt to Bohr’s defence, and Bush and Conant did likewise across the Atlantic. Bohr was not arrested.

Breaking the American monopoly

It was a bit of a puzzle. If you had just decided that your concern for what your country would do with a monopoly on atomic weapons was sufficiently strong to overcome your moral qualms about betraying your country’s military secrets, what did you do next? Where did you go? You couldn’t just look up a list of Soviet spies in the phone book.

Theodore Hall was just nineteen years old. Despite his youth, he had been identified by Los Alamos talent-spotters and had joined the still-growing ranks of physicists on the Hill in January 1944, together with his friend and fellow Harvard graduate student Roy Glauber. They had arrived at Lamy railway station on 27 January, having journeyed with an older physicist who had simply introduced himself as Mr Newman. They later realised he was John von Neumann, held in awe by the teenage physicists as the man who had transformed the mathematical basis of quantum theory in the 1930s.

The new arrivals received their briefing from Bacher and devoured Serber’s ‘Los Alamos Primer’. Hall was put to work in the experimental physics division (P Division). He quickly made a positive impression. In April he was assigned to work on implosion, studying the radioactivity of samples of radium-lanthanum that had been imploded using high explosive packed around the outside. These ‘Ra-La’ experiments, as they were called, were set up at a small laboratory in Bayo Canyon, south-east of the main Los Alamos site. They provided a measure of the uniformity of the explosive Shockwave that had been created. As the effects of the Pu-240 crisis rippled through the laboratory, the Ra-La experiments took on considerably greater significance.

Hall was a Jewish radical. He had once been a member of the American Student Union, several chapters of which were associated with the Young Communist League, but he had resisted being part of what he came to think of as a Communist front. He never joined the Communist Party. At Harvard, he had joined the Marxist John Reed Society, but did so under the influence of his eloquent room-mates at Leverett House rather than from political conviction. Nevertheless, as his first summer at Los Alamos wore on, concern that America was building a monopoly in atomic weapons gnawed at him. America was a democratic state but, Hall now pondered, could another depression drive it towards fascism, as had happened in Germany? And what would a fascist America do with its atomic monopoly?

After all, there was some sympathy and much talk among some of the Los Alamos scientists about the need to inform the Soviet Union of their
work. Surely, Hall reasoned to himself, the post-war world would be a safer place if the secrets of the atomic bomb were shared with the Soviets. Years later he recalled what was going through his mind:

Thinking back to the rather arrogant 19-year-old I then was, I can recall quite well what was on my mind at the time. My decision about contacting the Soviets was a gradual one, and it was entirely my own. It was entirely voluntary, not influenced by any other individual or by any organisation … I was never ‘recruited’ by anyone … As I worked at Los Alamos and understood the destructive power of the atomic bomb, I asked myself what might happen if World War II was followed by a depression in the United States while it had an atomic monopoly … It seemed to me that an American monopoly was dangerous and should be prevented.

Having decided to share with the Soviet Union those secrets to which he had access, he then had to face the challenge of finding an appropriate channel.

In October 1944 he took two weeks’ leave from Los Alamos and returned to New York to celebrate his twentieth birthday. He confided his intentions to Saville Sax, another Harvard student friend, and together they tried to figure out how to make contact with the Soviets. Through a series of rather comical trial-and-error approaches to Artkino Pictures, the Soviet film distributor, and Amtorg, they were both directed towards the Soviet journalist Sergei Kurnakov, who contributed to the Communist Party’s newspaper, the
Daily Worker.
But Kurnakov seemed rather cagey and promised little.

‘Do you understand what you are doing?’ he asked Hall. ‘Why do you think it is necessary to disclose US secrets for the sake of the Soviet Union?’

‘There is no country except for the Soviet Union which could be entrusted with such a terrible thing’, was Hall’s reply.

Hall handed over a report he had written about Los Alamos which listed the scientists working there, including Oppenheimer, Bethe, Bohr, Fermi,
von Neumann, Kistiakowsky, Segrè, Penney, Compton, Lawrence, Urey and Teller. In fact, Kurnakov was a Soviet agent, though a rather low-level one. He did not have the authority to make any commitments to the young would-be spies.

Concerned that Hall would return to Los Alamos without establishing the needed contacts, towards the end of October Sax blundered into the Soviet consulate, where he met Yatskov. Sax gave him another copy of Hall’s report on Los Alamos. Yatskov promised little more, but subsequently checked the students’ story with Kurnakov. There had been rumours of a secret ‘Laboratory V’, involved in research on the properties of U-235 and plutonium for the purposes of building an atomic bomb. Hall’s report appeared genuine. Yatskov’s most important source inside the Manhattan Project had gone missing in August, and he sorely needed a replacement.