The First War of Physics (16 page)

As Hitler began to use the emergency powers granted to him as Chancellor in 1933, Fuchs stepped up his activism. Slightly built and ascetic, he would have hardly posed much of a threat to the Nazi thugs now stalking the streets, yet he did not lack courage. Challenging the Brownshirts who were protesting against the rector of Kiel University, he was promptly beaten up and thrown in the river. When the Nazis began arresting Communists in significant numbers, Fuchs first went into hiding in Berlin before accepting the advice of his party comrades to leave the country. He was just 21 years old.

He found refuge in England in the home of Ronald and Jessie Gunn, a wealthy English couple who were also Communist sympathisers. The Gunns introduced Fuchs to Nevill Mott, professor of physics at Bristol University, who had just been appointed head of the physics department. Mott agreed to find a position for Fuchs as an assistant in his research team.

Where in Germany Fuchs had been an outspoken activist, characterised by an almost brash self-confidence and self-belief, in Britain he became shy and withdrawn, rarely speaking unless spoken to. He did not openly discuss politics. But the fact that Fuchs was no longer outspoken on political matters did not mean he had abandoned his political beliefs. After a time, he quietly registered his presence in Britain with Jurgen Kuczynski, a fellow member of the German Communist Party who had come to Britain in 1936. Unlike Kuczynski, Fuchs did not openly declare his affiliation to the party. Not that this mattered, perhaps, as the British police had already been informed that Fuchs was a Communist by the German Consulate in Bristol.

Mott soon found that Fuchs was a talented and persistent – if not dogged – theoretician. Fuchs worked diligently and secured his doctorate, on the application of quantum mechanics to metals, four years later. Realising that Fuchs’ personality and style would make for a poor lecturer, Mott sought and secured a post-doctoral research position for Fuchs with Max Born, another German émigré physicist, at Edinburgh University.

Born had helped to found the new quantum physics at Göttingen in the 1920s and early 1930s. Together with his assistant Pascual Jordan, he had in 1925 published an elaboration of a theory developed by Heisenberg which was to become known as matrix mechanics (an early version of quantum mechanics). Oppenheimer had studied for his doctorate under Born, and Fermi, Teller and Wigner had worked at different times as Born’s research assistants. Although a Lutheran, Born was classified by his ancestry as a Jew, and he lost his professorship in 1933. He had taken up the offer of a lectureship at Cambridge University before becoming a professor of natural philosophy at Edinburgh University in 1936.

Born warmed to Fuchs and, inasmuch as it was possible to be a friend with someone who never really opened up, Born and Fuchs became friends. As Fuchs’ reputation grew and he began to establish the beginnings of an academic career, he became somewhat less reserved. But he still kept his distance.

The Nazi–Soviet pact and the Soviet Union’s subsequent invasion of Finland were both shocks to Fuchs’ system, but he quickly managed to rationalise Stalin’s decisions as necessary preparation for the war between Germany and the Soviet Union which would surely follow. His application for British citizenship was overtaken by the outbreak of war in September 1939, and he became an enemy alien. Initially classified as a minimum risk to security because of his anti-Nazi stance, he was nevertheless interned on the Isle of Man in June 1940 as the Wehrmacht swept through Europe. From the Isle of Man he was moved swiftly to an internment camp at Sherbrooke, near Quebec City in Canada.

Most of the internees at Sherbrooke were Jewish, as they constituted the majority of the German émigré population in Britain at the time. Their Canadian guards were puzzled, as Jewish émigrés (including a few rabbis) hardly seemed to pose much of a threat to the security of a country at war with Nazi Germany. However, some among their number were not Jews, and among these were genuine Nazis. Fuchs resented being imprisoned alongside them.

The camp developed a thriving culture. Fuchs gave lectures on physics. Now back in a German community, he once again openly acknowledged
his Communist beliefs and regularly attended discussion meetings organised by fellow Communist internees. He was in touch with his younger sister Kristel, who had emigrated to America in 1936 and was now married and living in Cambridge, Massachusetts. Through one of her contacts she was able to arrange for Fuchs to receive some magazines. These were sent to Fuchs at Camp Sherbrooke by Israel Halperin, a young professor of mathematics at Queen’s University in Kingston, Ontario. Fuchs and Halperin had never met, but Halperin was a member of the Canadian Communist Party.

Born lobbied the British authorities and just six months after arriving at Sherbrooke, Fuchs was released and returned to Edinburgh. He left Sherbrooke on Christmas Day, 1940. Five months later he received a letter from Peierls inviting him to join a project that couldn’t be specified in detail, but which was expected to be important to the war effort. Fuchs accepted without hesitation.

There remained the question of Fuchs’ clearance to work on such a sensitive wartime project. MI5 had only two items of intelligence on him. There was the report from the German Consulate in Bristol, and a more recent report from one among the community of German refugees. Both reports declared that Fuchs was a Communist. Peierls was told that he could hire Fuchs provided he was told only what he needed to know in order to carry out his work, but Peierls claimed he could not work with Fuchs this way. The restriction was dropped and Fuchs was cleared to join the MAUD Committee team of physicists.

Fuchs quickly settled into his new surroundings in Birmingham. He set to work on two main tasks, the theory of nuclear chain reactions in U-235 and the theory of gaseous diffusion as a method for separating U-235 from U-238. Fuchs’ quiet reserve led Genia Peierls to coin him a new nickname – ‘penny-in-the-slot’. As she would explain to others: ‘Put a question in and you get an answer out. But if you don’t put anything in, you don’t get anything out.’

The MAUD report

On 15 July 1941, the MAUD Committee submitted two reports, one on the use of uranium for a bomb, the second on the use of uranium as a source of power. The first of these reports was unequivocal:

We have now reached the conclusion that it will be possible to make an effective uranium bomb which, containing some 25 lb of active material, would be equivalent as regards destructive effect to 1,800 tons of T.N.T. and would also release large quantities of radioactive substance, which would make places near to where the bomb exploded dangerous to human life for a long period.

The report went on to make three recommendations:

(i)  The committee considers that the scheme for a uranium bomb is practicable and likely to lead to decisive results in the war.

(ii)  It recommends that this work be continued on the highest priority and on the increasing scale necessary to obtain the weapon in the shortest possible time.

(iii) That the present collaboration with America should be continued and extended especially in the region of experimental work.

The committee physicists declared that they had started work on the project ‘with more scepticism than belief’, but, perhaps somewhat modestly, stressed that ‘the lines on which we are now working are such as would be likely to suggest themselves to any capable physicist’.

The report was optimistic about the likely time to production, suggesting that an atomic bomb could be available as soon as the end of 1943. Among the MAUD Committee physicists, only Blackett thought this overly optimistic. He very much doubted that so novel a project could be implemented without unforeseen difficulties likely to cause delays.

The MAUD Committee reports produced a flurry of activity in Whitehall. Lindemann had maintained a watching brief on the physicists’
deliberations and had attended many of the meetings of the technical sub-committee. He set great store by the judgement of Thomson and Simon and had been impressed by Peierls. Lindemann was now the British government’s leading scientific adviser. He had been ennobled as Lord Cherwell in June.

Cherwell had counselled Churchill in August 1939 that atomic weapons would not be available for ‘several years’. Although he had not been proved wrong, his initial scepticism about the possibility of an atomic bomb had now given way to great concern. Knowing Churchill liked briefing documents to occupy no more than half a page, Cherwell thought this one so important that he let it run to two and a half. But he still hedged his bets: ‘I would not bet more than two-to-one against, or even money,’ he wrote, ‘But I am quite clear we must go forward. It would be unforgivable if we let the Germans develop a process ahead of us by means of which they could defeat us or reserve the verdict after they had been defeated.’

Churchill sought the views of his Chiefs of Staff: ‘Although personally I am quite content with the existing explosives,’ he claimed, ‘I feel we must not stand in the path of improvement, and I therefore think that action should be taken in the sense proposed by Lord Cherwell: and that the Cabinet Minister responsible should be Sir John Anderson. I shall be glad to know what the Chiefs of Staff think.’ John Anderson, Lord President of the Council, was a former Home Secretary and physical chemist. He had completed his doctorate on the chemistry of uranium at Leipzig University.
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The MAUD Committee reports were formally reviewed by the Defence Services Panel of the Scientific Advisory Committee. This was chaired by Lord Hankey and included the physicist Sir Edward Appleton, the pharmacologist Sir Henry Dale, Nobel laureate and President of the Royal Society, and Sir Edward Mellanby, who had discovered vitamin D. The panel met with MAUD Committee physicists on 16 September. They discussed fuse mechanisms, the twenty-stage gaseous diffusion pilot plant, ICI’s commitment to source quantities of uranium hexafluoride and types of membranes that could be used in the diffusion plant that were available in America.

This was a meticulous review, which concluded:

We have been impressed by the unanimity and weight of scientific opinion by which the proposals are supported. The destructive power of the weapon which would thus be created, and the ultimate importance of the issues at stake, need no emphasis. Moreover, we have to reckon with the possibility that the Germans are at work in this field and may at any time achieve important results … For all these reasons we are strongly of the opinion that the development of the uranium bomb should be regarded as a project of first class importance and all possible steps should be taken to push on with the work.

On 20 September the Chiefs of Staff agreed, recommending that no time, labour, materials or money be spared. The panel completed its report, which also covered many points of policy and organisation, and submitted it to Anderson on 25 September.

Responsibility for the British project was passed to the Department of Scientific and Industrial Research. A senior ICI executive, Wallace Akers, was appointed to head it. Anderson and Akers gave the project a suitably misleading name – Tube Alloys – and the new organisation headed by Akers was called the Directorate of Tube Alloys. Akers was assisted by a deputy, Michael Perrin, also from ICI, and in October 1941 set up offices at 16 Old Queen Street in London, close to the headquarters of the SIS in Queen Anne’s Gate.

Leif Tronstad was one of the first to visit.

Of great value to the Soviet Union

On precisely the same day of the panel’s report to Anderson, NKVD spy Anatoly Gorsky (alias Soviet embassy attaché Anatoly Gromov) filed a
report from London to Moscow Centre. In Moscow the report was circulated by Yelena Potapova, an NKVD officer with good English and a grounding in science. The report read:

VADIM has relayed a report from [LISZT] about a meeting of the Uranium Committee of September 16, 1941. The meeting was chaired by BOSS.

VADIM was Gorsky’s codename. BOSS was a reference to Lord Hankey. Gorsky’s source was John Cairncross, Lord Hankey’s private secretary and a Soviet spy. Cairncross had been recruited to the Soviet cause in May 1937 by Anthony Blunt and Guy Burgess, as a replacement-in-waiting for another Soviet spy in the Foreign Office, Donald Maclean.
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Cairncross’s decision to betray atomic secrets to the Soviets was justified, in his own mind, as a way of providing practical support to an Allied power in the fight against the mutual threat of Nazism. Cairncross’s favourite composer was Franz Liszt.

The report went on to describe everything that had been discussed at the meeting, and so summarised the present state of the British atomic bomb project. The report concluded:

The Chiefs of Staffs Committee at their meeting on September 20,1941, made a decision to immediately launch construction in Britain of a plant to manufacture uranium bombs.

The Soviet Union thus knew of Britain’s decision to build an atomic bomb literally within days of the decision being made.

Soon the Soviets would know much more. While on a visit to London in late 1941, Fuchs decided to visit his friend Kuczynski. Perhaps Fuchs had guessed that Kuczynski was also working for Soviet intelligence. In fact, Kuczynski was an agent of the GRU.
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Fuchs had advised him that he had information about a secret project that could be of great value to the Soviet Union.

Fuchs became a Soviet spy.

Kuczynski put Fuchs in contact with Simon Kremer, secretary to the military attaché at the Soviet embassy in London. Kremer was also an agent of the GRU, known to Fuchs only by his cover name Alexander. Kremer gave Fuchs some rudimentary instruction in the tradecraft of a spy and they organised clandestine meetings at a house near Hyde Park. At these meetings Fuchs would hand over pages of carefully typed or handwritten script summarising the work in which he himself had been directly involved.

Despite his commitment to the Soviet cause and his decision to betray the secrets of the country for which he was now working, Fuchs adopted his own strict ethical code. He had relatively free access to the work of others, such as Peierls, and had sight of American research, but he refused to pass on documents relating to anything other than his own work. However, he did provide verbal summaries of what he knew.