Half-Life: The Divided Life of Bruno Pontecorvo, Physicist or Spy

by Close, Frank

  Before “Helen” began her work as a courier to and from Los Alamos, she traveled to the Canadian border to meet a contact who handed over papers that had originated in Canada. This occurred in early 1945. The name of her contact has never been revealed. Although it is tempting to speculate that her appointment might have been with Bruno Pontecorvo, especially given Skinner’s observation that Bruno traveled to the US-Canadian border regularly, the dates when Pontecorvo is known to have made such trips do not mesh easily with those of Lona Cohen. Pontecorvo visited the United States briefly during the 1944 New Year, and returned to Canada on January 2; however the KGB didn’t activate Lona Cohen in Canada until January 11.42 When interviewed years later, she remembered her first courier visit to the Canadian border as being “sometime in the first chilly months of 1945.” Pontecorvo’s next recorded trip into the United States occurred in May, which does not fit with Cohen’s description, although it’s possible her memory of the time frame is unreliable.

  By the end of the war, Lona Cohen was deeply involved in smuggling information both from Los Alamos and from Canada. In November 1945, Morris was discharged from the army and immediately signed on again with the KGB. Although Gouzenko’s defection in September had directly compromised only the GRU networks, the KGB took care to protect itself by putting its agents into effective hibernation for two years. Thus, the Cohens went dormant, and carried on with their lives like model US citizens.43 Years later, when a historian of the KGB interviewed Lona and Morris in Moscow, she turned to her husband and said, “Remember the Canadian case? We are connected.”44

  By the end of 1947, Lavrenti Beria was desperate to know about recent Western progress with nuclear weapons. It was around this time that he reactivated the wartime networks. In England, Klaus Fuchs, who had been quiet since 1946, linked up again with a Soviet contact and informed him that Enrico Fermi and Edward Teller, now at the University of Chicago, were interested in creating a thermonuclear “hydrogen” bomb, which used tritium and deuterium. In North America, the Cohens also resurfaced. As it happened, Ted Hall was working at the University of Chicago, and the Cohens, sensing a pathway to news about Fermi and Teller, renewed contact with him.

  Ted Hall’s wife, Joan, recalls a meeting that she and Ted had with the Cohens in 1949. Morris Cohen had met Ted Hall the previous year, and put great pressure on him to become active again as a spy.45 Cohen was successful, but within a year Hall wanted to disconnect once more, which led to the meeting of Joan and Ted Hall with Lona and Morris Cohen in a New York park.46 In Joan Hall’s opinion, the Cohens were trying hard to renew their old contacts, in part to prove to Moscow that they, Lona and Morris, were still a powerful force.

  The Cohens were able to renew their link with Hall, at least in 1948 and 1949. They also succeeded with an agent based in Canada.

  Lona Cohen’s official KGB biography reveals that, around this time, she “obtained a sample of uranium from Canada,” which she transported to her Soviet contact in New York.47 V. N. Krasnikov, the KGB’s resident deputy in New York, recalled that in the later part of the 1940s he was not only interested in the H-bomb, but also in uranium ores: “We contacted people on this issue. In my safebox in New York there was an envelope with powdered uranium.” He added, “The only uranium known to have come to New York is credited by Russian intelligence to Lona Cohen.”48

  Lona Cohen’s uranium sample was not the same as Nunn May’s, which had been handed over in the summer of 1945 and taken under close guard from Ottawa to Moscow. After Nunn May’s uranium arrived in Moscow, Igor Kurchatov asked for more samples. Cohen’s uranium was then obtained “on orders of the Centre.”49 Combined with Krasnikov’s account given above, this suggests that Cohen’s uranium was obtained later than 1945. Furthermore, uranium from the Canadian reactor was only available after 1947, and the Cohens had gone underground from late 1945 until the start of 1948.

  By 1948, the NRX reactor at Chalk River was working. It produced both plutonium and U-233. Joan Hall’s impression that the Cohens were under pressure to reactivate their networks at this time would suggest that, in addition to approaching Ted Hall, they also contacted their former source or sources in Canada. This period of the late 1940s is also when the Soviets began to show interest in developing a hydrogen bomb; this requires tritium, which can be produced in a heavy-water reactor. Hence the Soviets would have had a real interest in obtaining the blueprints of the Canadian reactor, as well as uranium samples, at this stage.

  Lona’s source in Canada has never been identified. If Gordievsky is wrong about Pontecorvo being the source, some other individual has managed to keep their secret ever since.

  HALF TIME

  TEN

  CHAIN REACTION

  1949–1950

  IN 1949, BRUNO’S ODYSSEY BROUGHT HIM TO HARWELL, IN THE HEART of England, to work on the British nuclear reactor program. He also devoted some of his time to fundamental work studying cosmic rays. However, his other love, the neutrino, would remain tantalizingly out of reach—the reactors being designed at Harwell would be unable to generate enough neutrinos for his needs.

  Harwell village, with its half-timbered, thatched cottages, could serve as a model for a classic English picture postcard. The Downs, as the uplands of southern England are known, cross the landscape about ten miles to the south. For most of the 1930s this area was a peaceful idyll, which was shattered in 1939 when an airfield was built to house Wellington bombers. After the end of the war, in 1946, this site was taken over by “the Atomic,” as Harwell Laboratory was affectionately known.

  The Atomic had an air of mystery, even of menace. Tall chimneys, tower blocks, and offices of red brick, prettified with sash windows, gave the place the appearance of an industrial site, which in effect it was. The runways of the former airfield became roads, and the vast areas of concrete where the planes had once taxied became bus terminals: large numbers of coaches were needed to ferry workers between the laboratory and the surrounding villages, which were several miles away. Behind the security fence, which was manned by armed police officers, the abandoned aircraft hangars became laboratories. Those allowed inside would discover the postwar state of the art in big science. The walls within the hangars housed three stories of offices and labs, which were reached by metal staircases. From walkways, high above the hangar floor, you could look down on piles of graphite and concrete blocks, which eventually would house a nuclear reactor.

  The scientists wore suits and ties. Many completed the ensemble with a waistcoat, within which a pencil or fountain pen would nestle, ready to record data. They smoked pipes as they watched lights flicker on monitors, recorded the readings from dials, or adjusted Bakelite knobs on the electronics. That was how science was done in the Britain of the 1940s.

  Seen from sixty years later, there is inevitability to Bruno Pontecorvo’s disappearance, a domino effect as world events cascaded through the first half of 1950 toward a terrible personal climax.

  Bruno had, after all, always felt pursued: by the fascists in Italy, by the Nazis in France, by the FBI in America; he later sensed a general atmosphere of suspicion in Canada. He had only been at Harwell a year when, in February 1950, his colleague, Klaus Fuchs, was arrested. Pontecorvo and Fuchs were independent colleagues, but shared common ideals, and the effect on Bruno can’t have been calming.1

  When tectonic plates shift on the ocean floor, waves spread imperceptibly until, perhaps thousands of miles away, a tsunami reaches land and wreaks havoc. For Pontecorvo, the disaster struck in September 1950. Unseen waves had been building for months, but their source, the metaphorical quake that set the whole saga in motion, took place back in 1949, in the United States. It was Bruno’s old friend, Emilio Segrè, who set the fateful events in motion.

  In the US, Senator Joseph McCarthy’s witch hunts and the persecution of “Reds” initially began as a Kafkaesque loyalty test: to prove your loyalty, give us the names of people known to you to be communists, or to have professed views th
at are communist, or left of center, or. . . . And names would be duly provided. Anyone who refused to take the test was immediately damned. It is a marked irony that the US was adopting practices that were de rigeur in the USSR, the very regime that was being painted as the new Satan.

  Which is how Emilio Segrè was cast as Judas Iscariot.

  Segrè, like Pontecorvo, was one of the Via Panisperna Boys. During the war, as we saw, their research was appropriated by the military. Now, postwar, the US government’s newly formed Atomic Energy Commission (AEC) was taking over this area. The slow-neutron method, developed and patented by the Via Panisperna Boys, was pivotal to their vision. Segrè was financially sophisticated and eager for the monetary rewards that this patent promised. Negotiations between the AEC and the patent holders were dragging on, however, and the US government was making strategic investigations into the political background of the “Boys,” looking for dirt to bolster its case against them.

  Segrè felt compromised. He was now working at the University of California, which became infamous for its enthusiastic application of the loyalty test to its employees. Segrè knew Pontecorvo’s family well. He was aware that Bruno’s siblings included professed communists, and that his cousin Emilio Sereni was a communist member of the Italian government. Segrè feared that his former association with Pontecorvo could call his own loyalty into question. So on November 9, 1949, Segrè met with Robert Thornton, an old friend from Berkeley who was now an official at the AEC, and told him about Bruno’s communist associations. Thornton passed this information on to the FBI.2

  The FBI checked their files and, realizing that Pontecorvo was working at Harwell in the UK, duly informed the British security services. The FBI also gave MI5 a second piece of information that corroborated what Segrè had said. Sent on December 15, the note “regarding possible communist or pro-communist tendencies of two nuclear physicists and a biologist,”3 keeps the names of its sources secret, but the content shows that the informant is not Segrè.4 The note reads, in part:

  Informant A of proven reliability on communist matters vouched for the reliability of informant B who said he was acquainted with three individuals in Paris under Prof Langevin who were exposed to the virus of communism. These were Bruno Pontecorvo, Sergio de Benedetto and Salvatore Luria. [B] said that he later met Bruno Pontecorvo on the ship Quanza and through him met Benedetto and Luria in New York City socially. [B] reported that he gained the impression in Paris that these three were either pro-communist or outright communists. He said that conversations that he had with them in the USA tended to strengthen his belief. The last time he saw them was in 1944. [B] reported that all three were friendly with Mr Sereni, a communist.

  MI5 took note. Someone highlighted the above paragraph in Pontecorvo’s file.5

  The testimony continued: “[B] reported Ambroglio and Berti had returned to Italy and Sereni had not been in the USA. [B] reported that Pontecorvo at one time was definitely aligned with the communists. In addition he reported that his brother-in-law (Ducio Tabet) was also pro-communist and had returned to Italy.” The FBI followed up on Bruno’s family and discovered that Bruno’s sister Giuliana, who had also come to their attention as a possible communist, lived a couple of doors away from an alleged member of Comintern.6

  The emerging picture of Bruno Pontecorvo at the FBI was of a nuclear scientist who was a communist, in an extended family of communists whose members were in all likelihood well connected with Comintern. If Segrè had hoped to smooth his own vetting process, and his claim on the patent, the attempt had backfired. Segrè and “Informant B” merely fed the anticommunist hysteria already rampant within the Atomic Energy Commission and the FBI. Segrè’s attempt to provide security for himself, by naming Pontecorvo, instead encouraged the AEC to dig deeper into Bruno’s activities. During 1949 and early 1950, the FBI doggedly investigated Pontecorvo’s politics.

  In the United Kingdom, by contrast, MI5 did nothing. Their lack of action at this time is possibly due to the fact that when the news of Pontecorvo’s communist associations arrived in 1949, the Harwell security team and MI5 were heavily occupied with the case of Klaus Fuchs. Fuchs was interrogated on December 21, again on the thirtieth, and for a third time on January 13.7 By the end of January, the investigation of Fuchs was complete, and he was arrested on Friday, February 3, 1950.

  The following week, starting on the tenth, Harwell hosted a four-day conference to decide which items in the field of nuclear physics should remain secret and which could be declassified now that the war was over. It was during this gathering that news of America’s growing concerns about Bruno reached Harwell and sealed his fate.

  On the Saturday evening there was a reception at Ridgeway House—an austere, government-standard brick building, which was used as a hostel for visitors, and doubled as an event center thanks to its large hall. Bruno had been invited to the reception by Sir John Cockcroft, “to meet the US and Canadian Delegates.”8 The American delegation from the AEC included Robert Thornton. Although on the surface the occasion was gregarious, with colleagues recalling their times together during the war, the undercurrent must have been cool. Thornton had already transmitted Segrè’s information about Bruno to the FBI. Now, at some point during the conference, he told Cockcroft that Pontecorvo and his family were communists.9

  This news worried Cockcroft. He had known Bruno as both a colleague and a friend during their time in Canada, and had expressed concerns about his background in 1946 when his transfer to Harwell was first mooted. However, there had been no direct linkage of Pontecorvo to communism at that stage—the FBI’s 1942 message about the communist literature in Pontecorvo’s house having gone astray. Now Cockcroft passed Thornton’s news to his security chief, Wing Commander Henry Arnold, and instructed him to get to the bottom of it.10

  Arnold, slightly built and suave, was a model “English gentleman.”11 Lorna Arnold, the distinguished historian of the British hydrogen bomb (and no relation to Henry), described him as the “perfect intelligence officer.” At the end of the 1950s, Henry and Lorna worked in the same branch of the UK Atomic Energy Authority, and the internal mail service kept getting their correspondence mixed up. As a result, Lorna recalled, “Henry was always coming to my office.” She remembered him as “very kindly, pleasant and courteous; average in height and build.” He was the perfect intelligence officer, she explained, because “his unobtrusive build and his personality helped him merge into the background. He was very observant and very tuned into people.” He was also very good at understanding the psychology of suspects, winning their confidence and then destabilizing them.12

  Arnold’s style was “softly, softly.” He maintained discretion by meeting with Pontecorvo in connection with his regular work. At the time, Pontecorvo’s research was focused on cosmic rays, and he was hoping to go to the Swiss Alps to work on an experiment being conducted on the Jungfraujoch. Trips abroad required approval from the security division, so Arnold used this formality to make seemingly innocent conversation about Pontecorvo’s trip. Arnold asked whether he would be visiting his parents, who lived in Milan, or his siblings elsewhere in Italy. Bruno confirmed that he had last seen his brother Gillo at an international conference in Lake Como in 1949, and he expected to meet him during the trip. During this discussion, Arnold wheedled out significant information, as he reported on March 1 in a phone call to MI5: “Pontecorvo disclosed that his brother, who is also a scientist with an international background, was an active communist.”13

  This set alarm bells ringing, if only quietly at first. Arnold went on to report that Bruno had recently been offered a job at the University of Liverpool. An easy way to eliminate any possible security risk would be to transfer Bruno Pontecorvo there, away from the classified work at Harwell. Arnold promised to send MI5 the latest facts about the Pontecorvo family, “so that [MI5] could offer advice in due course.”

  More information about Pontecorvo’s family arrived at MI5 the next day. This news cam
e not from Arnold but from an unexpected quarter. The Special Branch of the British police, which focused on security issues, reported that a source in Sweden had unequivocally asserted that Pontecorvo’s wife, Marianne, was a communist: “In Enskede, a suburb of Stockholm, there lives a Fru PONTE CORVO a Swedish national married to Italian born subject whose present nationality is unknown. Mr PONTE CORVO lives in England where he works in one of the British Atom Installations. Fru PONTE CORVO was in England in summer 49 with her two [sic] sons. Both she and her husband are described as avowed communists.”

  This last remark has been highlighted with two solid lines in the margin. The letter commented, “This report would appear to refer to Bruno Pontecorvo employed in [Harwell].”14

  Although the broad details are right, the letter is a classic case of the game of “telephone.” Somehow the Swedish authorities thought Bruno had six sisters and one brother, rather than three and four, and that he had two rather than three children. More significant is that in reality “Fru PONTE CORVO” lived in England and had only been visiting her parents in Sweden. When such errors are discovered, the recipient has to decide whether they are trivial flaws in transmission, or instead constitute evidence that the subject of the report has been misidentified. A few weeks later these errors were cleared up, with an apology from Special Branch. In addition, perhaps to save face, the writer insisted that their source “re-emphasises the authority of the informant.”15

  In March, Arnold must have been busy with other matters as he sent MI5 no further information about Pontecorvo. In the meantime the directors and their deputies in the MI5 divisions of Counter-espionage (section B), Examination of Credentials (section C), and Security (section D) were exchanging minutes and papers about Pontecorvo. They had to assess the level of threat, and then decide what to do about it. On March 20 Colonel John Collard of section C judged that the credibility of the Swedish source needed to be determined. Collard’s opposite number in Counter-espionage, J. Robertson, decided that further investigation should be undertaken by his own branch. Robertson’s colleague W. S. Mars, concerned about the lack of progress, also added a note to the file on March 20: “Is any news expected from Arnold soon?” On March 26 Collard spoke by phone with Arnold, who “undertook to see Pontecorvo again at a suitable opportunity.”