The First War of Physics (28 page)

Feklisov later explained why he had not been troubled at the thought of spying on his American ally. He had noted the political double-standards of the Roosevelt administration. The Soviet Union was an ally only because Soviet Communism was temporarily a lesser evil than German National Socialism. With his privileged access to detailed information on ‘LendLease’ aid, he was able to surmise that the Americans were deliberately providing only defensive, not offensive, weapons to the Soviet Union. It seemed to him that America and Britain preferred to see the Soviet Union weakened as much as possible by its war with Nazi Germany, making it all the easier for them to control post-war events. ‘When you know you are being taken advantage of,’ Feklisov wrote years later, ‘you have every right to be clever.’

The San Franciso
rezidentura
had been established in November 1941 and was staffed by vice consul Gregori Kheifets and third secretary Pyotr Ivanov. They were charged with development of an intelligence network targeted against Germany and, subsequently, Japan. Kheifets and Ivanov immersed themselves in the activities of the local American Communist Party and progressive unions such as the Federation of Architects, Engineers, Chemists and Technicians (FAECT).

Although the necessary intelligence infrastructure was in place in America as Kurchatov issued his appeal for more information about the American atomic programme, the Soviet spies did not have direct access to America’s nuclear scientists. Fitin therefore decided to establish a
rezidentura
in New York, designated ‘XY’, dedicated to the task of gathering scientific and technical intelligence. Leonid Kvasnikov, an NKVD agent with some knowledge of engineering, was assigned to head it. He arrived in New York in January 1943 and took up the position of deputy
rezident.

Fitin gave the operation the codename
(ENORMOZ), meaning, literally, ‘enormous’.

The Chevalier incident

Kurchatov had put the Rad Lab at the top of his list of targets for Soviet espionage, and Kheifets and Ivanov had already begun recruiting intelligence contacts from among the group of radical physicists at the Berkeley laboratory. Given Oppenheimer’s ‘leftwandering’, it was inevitable that they would try to approach him too.

Kheifets possessed an outgoing, friendly personality and spoke good English. He was familiar with the milieu of physicists, having once targeted Fermi and Pontecorvo as potential recruits to the anti-fascist cause while deputy
rezident
in Rome in the 1930s. He met the Oppenheimers at a couple of fund-raising events in December 1941 and 1942 (Oppenheimer knew Kheifets only as ‘Mr Brown’). Shortly after his first meeting with Oppenheimer, Kheifets reported to Moscow of a private lunch conversation in which Oppenheimer had talked of Einstein’s letter to Roosevelt and his frustration at the lack of progress on what Kheifets understood to be a secret atomic weapons project.

Late in 1942, Ivanov had approached George Eltenton, a British chemical engineer who had worked for a time at the Leningrad Institute of Chemical Physics with the noted Soviet chemists Yuli Khariton and Nicolai Semenov. During this period both Eltenton and his wife Dolly had become dedicated Communists. Eltenton was now working at the Shell Development Laboratory in Emeryville, about eight miles from Berkeley, and organised the local FAECT chapter. Ivanov explained that he knew that the work at the Berkeley Rad Lab was connected with atomic energy. ‘Do you know any of the guys or any others connected with it?’ he asked Eltenton. Eltenton volunteered to make an approach to Oppenheimer through their mutual friend, Haakon Chevalier.

Chevalier was a native of New Jersey, born of French and Norwegian parents. He was professor of French literature at Berkeley, an accomplished translator, and author of a biography of Anatole France. A visit to France in 1933 and the outbreak of the Spanish Civil War in 1936 had encouraged his left-wing sensibilities in the direction of Communism. He was introduced to Oppenheimer at a meeting of the Teachers’ Union. They became good friends.

‘Eltenton’s manner was somewhat embarrassed’, Chevalier later wrote. ‘He seemed not too sure of himself. Through his roundabout phrases it gradually became clear to me that what the people behind him were really interested in was the secret project Oppenheimer was working on.’ According to Chevalier’s later account, he rejected the idea of spying for the Soviet Union but decided to mention Eltenton’s approach to Oppenheimer.

The opportunity to do this arose during a dinner hosted by Oppenheimer and Kitty at their home on Eagle Hill.
⁴
The Oppenheimers were preparing to leave Berkeley for Los Alamos, and wanted to share a farewell dinner with their closest friends. With Kitty and Chevalier’s wife Barbara playing a duet at the piano, Oppenheimer headed for the kitchen to fetch mixers and ice to make his legendary martinis. Chevalier followed.

Interpretations of what happened next vary. According to Chevalier, he simply described the approach that had been made to him by Eltenton. Oppenheimer agreed that Chevalier had been right to tell him about it and looked visibly shaken. Nothing more was said.

In later versions of the incident, Oppenheimer claimed that Chevalier had said that, through Eltenton, he had ‘means of getting technical information to Soviet scientists’, an overt suggestion that Oppenheimer pass atomic secrets to the Soviet Union.

Chevalier’s marriage was already in trouble, and some 40 years later his embittered ex-wife Barbara made plain Chevalier’s motives that night: ‘I was not, of course, in the kitchen when Haakon spoke to Oppie, but I knew what he was going to tell him. I also know that Haakon was one hundred per cent in favour of finding out what Oppie was doing and reporting it back to Eltenton. I believe Haakon also believed that Oppie would be in favour of co-operating with the Russians. I know that because we had a big fight about it beforehand.’

According to the version told many years after the event to Oppenheimer’s secretary Verna Hobson, Kitty, not wanting Oppenheimer and Chevalier to be alone, had also entered the kitchen and had heard Chevalier’s proposal. It was she who pointed out that passing information to Soviet scientists would be treason.

Irrespective of who said what, it is clear that Oppenheimer rejected this attempt to recruit him as a Soviet spy, if that was indeed what it was. However, it was not Oppenheimer’s response that was to cause him problems. The ‘Chevalier incident’ was soon to return to haunt him in other ways.

Although the FBI had no knowledge of the burgeoning atomic programme, they uncovered the first hard evidence for Soviet espionage against it on 29 March 1943. The FBI had planted bugs in Steve Nelson’s home, as well as in his Oakland office. Nelson returned home late from a union meeting to find someone, identified only as ‘Joe’, waiting patiently to talk to him. Joe explained that the Rad Lab physicists working on the bomb programme were soon to be relocated, and that he would be joining them.

They discussed ‘the professor’, who appeared to have forsaken his commitments to the Communist cause. ‘To my sorrow, his wife is influencing him in the wrong direction’, Nelson said. Nelson then pumped Joe for information, and though initially reluctant, Joe eventually described aspects of the Rad Lab work on electromagnetic separation and the site in Tennessee where a large-scale separation plant was already under construction.

The direct link with Soviet intelligence was subsequently confirmed by FBI surveillance. Nelson was observed meeting with Ivanov at San Francisco’s St Joseph Hospital on 6 April. In a further bugged conversation between Nelson and a man later identified as Zarubin, recorded on 10 April, Zarubin was heard counting out wads of money, ‘like a banker’. The two then discussed the Soviet intelligence network in America.

Whoever ‘Joe’ was, he was a Rad Lab physicist passing atomic secrets to the Soviets. And he was about to move to Los Alamos.

Los Alamos primer

Oppenheimer’s tenure as head of the Los Alamos laboratory got off to a shaky start. It seemed that those who had declared Oppenheimer unfit to run a hamburger stand were going to be proved right.

The first few months of construction of the new facility were chaotic, the result of a general lack of leadership and direction. Despite cajoling, Oppenheimer had failed to produce an organisation structure for the laboratory. Even the very idea of an organisation structure was new to him. As far as he was concerned, about 30 physicists were heading for New Mexico where they would build an atomic bomb. What could be simpler? When confronted about the chaos at a dinner party at his Eagle Hill home, Oppenheimer exploded with rage.

But rage was followed by a calm appraisal of the situation, and Oppenheimer learned quickly. By March 1943 he had produced an organisation chart and revised his estimate of the size of the Los Alamos population from 100 to 1,500. He began to take managerial control. Oppenheimer, Kitty and their young son Peter (nicknamed ‘Pronto’ because of his very prompt appearance, less than seven months after the Oppenheimers were married) arrived in Santa Fe on 16 March 1943. A few weeks later they moved up to ‘the Hill’, as the fledgling laboratory had become known.

They moved into a modest cabin, one of six original Ranch School buildings which were fitted with bathtubs, in contrast to the accommodation now being hastily erected by the Army Corps of Engineers, which were fitted only with showers. There were trucks and bulldozers everywhere, as 3,000 construction workers erected the main buildings, including five laboratories, a machine shop, a warehouse and barracks. The spring thaw had turned the unpaved roads to thick mud. It was a vision straight out of
the wild west. On his arrival, Bethe was shocked by the isolation and the shoddy buildings.

By early April, about 30 physicists had gathered on the Hill. Oppenheimer had moved quickly to recruit the ‘luminaries’ of the previous year’s summer school – Bethe, Bloch, Teller and Serber among them. He had also recruited a young Princeton physicist called Richard Feynman, whose bongo-playing left an indelible impression on Teller, sitting in the next room.

Feynman was young (he would celebrate his 25th birthday on 11 May), precocious and passionate about physics. He was now meeting for the first time colleagues familiar to him only by their names, which he had seen in the pages of
Physical Review.
But his was not the kind of personality that was easily over-awed. He quickly gained a reputation for his voluble debating with Bethe, who needed and welcomed the stimulation, and was made a group leader under Bethe. His wife Arline was suffering from tuberculosis and had at Oppenheimer’s direction been installed in a clinic in Albuquerque so that Feynman could make frequent visits.

Fermi’s work on uranium–graphite reactors in Chicago was too important for him to abandon in favour of joining the team of physicists assembling at Los Alamos. And yet Fermi’s grasp of the experimental problems and his insight were too important to forgo. Oppenheimer settled for a compromise. Fermi would serve as a visiting consultant to the Los Alamos laboratory.

Oppenheimer had wanted to recruit Rabi as associate director of the laboratory, but Rabi was working on radar at MIT and argued that this was more important than working instead to turn three centuries of gloriously successful physics into weapons of mass destruction. Although Rabi’s reasons were different, Oppenheimer was able to persuade him to accept the same compromise solution as Fermi. With some reluctance, Rabi too became a visiting consultant to Los Alamos.

On 15 April, the Los Alamos physicists assembled for their first meeting, in an empty library, and the first of a series of inaugural lectures to be delivered by Serber. Groves’ opening remarks were downbeat. It seemed as though he was already planning for failure and anticipating what he would
say to the congressional committee that would undoubtedly be convened to find out how the money had been squandered.

Serber then delivered his first lecture, summarising the output of the summer study group and the work on fast-neutron fission that had been done in the last year. He was not a great speaker, but this was an occasion on which the substance was much more important than the style of delivery. ‘The object of the project,’ Serber said, ‘is to produce a
practical military weapon
in the form of a bomb in which the energy is released by a fast-neutron chain reaction in one or more materials known to show nuclear fission.’
⁵
For many in the audience, compartmentalisation had so far prevented them from understanding the full implications of the work they had been doing. Some had guessed at the details. Others had heard rumours. Now they started to become absorbed by the larger problem.

On the surface, making an atomic bomb seems relatively straightforward. Take two pieces of U-235 or plutonium whose masses are subcritical when kept apart, but which when brought together form a mass in excess of the critical mass, which then explodes. But there are some not-so-straightforward hurdles to be overcome.

The first is concerned with efficiency. The critical mass of U-235 had by this stage been fixed at around 200 kilos – a little impractical for a weapon to be dropped from an aeroplane. The study group had proposed to raise the efficiency of the device and so reduce the amount of active, fissionable material required by surrounding it with a ‘tamper’ – made of U-238 or gold – to reflect neutrons back into the active material. For U-235 this brought the critical mass down to fifteen kilos. For plutonium the critical mass was estimated to be just five kilos with a uranium tamper.