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

by Close, Frank

  11. Mafai, Il lungo freddo, p. 164.

  12. Gil Pontecorvo interview, January 20, 2012.

  13. This is the date as Gil recalled it, sixty years later. Actually September 16 is the date he started school in 1949. In 1950 the term started on September 19. This illustrates both the detailed level of Gil’s memories, as well as the subtle tricks the mind plays over time.

  14. Gil Pontecorvo interview, August 25, 2011.

  15. Sereni’s diary shows that he went back and forth between the USSR and the West during this period. This was because he was a major party member, whom the Soviets saw as key to spreading communist influence in the world. It is thus possible that Bruno did not fully realize that he would be cutting himself off so thoroughly; for him, the move to the USSR could have been merely another stop on his life’s journey. Simone Turchetti interview, October 5, 2011.

  16. The early years of Laboratory Number Three are described in Boris Ioffe, “The First Dozen Years of the History of ITEP Theoretical Physics Laboratory,” European Physical Journal H 38, no. 1 (January 2013): 83–135.

  17. Ioffe, “A Top Secret Assignment,” p. 31; Boris Ioffe e-mail, August 5, 2011; Giuseppe Mussardo interview, December 12, 2012.

  18. The eventual success of the Soviet H-bomb occurred because Andrei Sakharov found a way (known as the “layer cake”) to make a bomb using a minimal amount of tritium, and Vitaly Ginzburg had the insight that tritium could be made within the bomb itself by bombarding lithium deuteride with neutrons.

  19. Ioffe, “A Top Secret Assignment,” p. 31; Boris Ioffe e-mail, August 5, 2011; Giuseppe Mussardo interview, December 12, 2012.

  20. Laboratory Number Three was officially established in December 1945, but during 1946 “no real work” occurred. Serious work happened only from 1947 onward (Boris Ioffe e-mail, August 5, 2011). Nunn May had been exposed in 1945. There is no mention of any blueprints in his deathbed statement (Broda, Scientist Spies, and Paul Broda e-mail, October 10, 2013). Only the final stage of the blueprints’ journey is known. Yakov Terletsky, a physics professor at Moscow State University, was a part-time employee of the KGB. His role was to filter all material on atomic projects coming from abroad, and ensure that the information reached the relevant teams in the USSR.

  21. Ioffe, “A Top Secret Assignment,” p. 31; Boris Ioffe e-mail, August 5, 2011; Giuseppe Mussardo interview, December 12, 2012.

  22. This comes via a trusted scientific colleague from the former Soviet Union, who was involved in the nuclear physics program in the 1950s and heard this from “the grapevine” decades ago. While I am confident of the reliability of my colleague, who also trusts his source, now dead, I cannot assess the accuracy of his source or his memory after so long.

  23. According to Popov, Pontecorvo “was regarded as so important that he was interviewed by Beria” (quoted in Pincher, Treachery, chap. 48 and Chapman Pincher interview, November 14, 2014). Given Pontecorvo’s significance as a nuclear scientist, the fact that the interview allegedly took place in the Kremlin, and Beria’s role in the Soviet atomic program, this is plausible. However, my informant was unable to confirm Beria’s presence. “Gray and mustard” is artistic license based on my personal experience of Soviet government decor from the 1970s. Henry Ford’s cars were famously available in any color as long as it was black. A similar uniformity seems to have applied to walls in the USSR. I have assumed that the same was true on this occasion.

  24. In Joan Hall’s opinion, if Ted had been forced to choose between fleeing to the USSR or facing ten years in jail “or worse, the electric chair,” his decision would have been obvious. Joan Hall interview, May 1, 2013.

  25. Bruno’s version of his arrival in the USSR was given decades later. Whether he was genuinely a willing participant, or if this was an example of revisionist history, only he knew. Clearly, if Bruno had the intention to move to the USSR before the Pontecorvos left England, they could have taken more suitable belongings. Anna had asked if she could hitch a ride with them en route to Italy. Her presence made space tight. She had to repack and leave a case behind in England. If Bruno were already planning to leave England forever, it would have been easy for him to politely tell Anna that there was no space for her, and then pack for his own needs more appropriately. Clothing and financial support could be provided by the Soviets, but personal memorabilia and family documents could not. Ronnie Reed of MI5 concluded as much in 1951.

  26. Remark by anonymous relative, confirmed by Anna Pontecorvo, March 21, 2012.

  27. This is the account Bruno gave to Miriam Mafai years later. The idea that Gil, at age twelve, had such a sophisticated understanding of socialism as to “scold” his mother seems like propaganda. If true, however, it would suggest that the family had discussed communist ideology in the home for some time.

  28. Gil Pontecorvo interview, February 24, 2011.

  29. Mafai, Il lungo freddo.

  30. Gil Pontecorvo interview, August 25, 2011.

  CHAPTER 15

  1. Pollock, Stalin and the Soviet Science Wars, p. 91, as quoted in Turchetti, The Pontecorvo Affair, p. 184.

  2. Ioffe, “A Top Secret Assignment”; Boris Ioffe e-mail, August 5, 2011; Giuseppe Mussardo interview, December 12, 2012.

  3. Dubna could accelerate deuterons to a kinetic energy of 280 MeV, alpha particles to 560 MeV, and protons to 680 MeV.

  4. Venedict Dzhelepov, in BPSSW. There is also some unsubstantiated gossip that Dzhelepov, who later became director of the laboratory, might have played a role in recruiting Bruno Pontecorvo to Dubna. Ugo Amaldi and Giuseppe Fidecaro interviews, November 9, 2013.

  5. TNA KV 2/1888.

  6. Joint Committee on Atomic Energy, “Soviet Atomic Espionage,” April 1951, http://archive.org/stream/sovietatomicespi1951unit/sovietatomicespi1951unit_djvu.txt.

  7. For example: “Prof Pontecorvo is said to have been seen [at Kamenice]” where “fresh uranium deposits have turned up” (“Two New Czech Atom Plants,” Daily Telegraph, March 21, 1951).

  8. Boris Ioffe video interview by Giuseppe Mussardo, 2012 Boris Ioffe e-mail, August 5, 2011; Ioffe’s interview by Giuseppe Mussardo, viewed by author December 12, 2012.

  9. Samoil Bilenky interview, October 12, 2013.

  10. Boris Ioffe video interview by Giuseppe Mussardo, 2012, viewed by author December 12, 2012.

  11. This was very similar to the “classical superbomb” developed by Edward Teller in the United States. The idea came to the USSR via Klaus Fuchs. See also Rhodes, Dark Sun, p. 256; In “A Top Secret Assignment,” p. 25, Ioffe argues that the idea was developed by Soviet physicists but that its true origin was known only to a handful.

  12. Ioffe, “A Top Secret Assignment,” p. 28.

  13. For the history of Pomeranchuk’s book as well as his career, see http://www.kipt.kharkov.ua/itp/akhiezer/en/recollections/pomeranchuk/.

  14. Burke, The Spy who Came In from the Co-op, pp. 13 and 122.

  15. Lorna Arnold interview, March 18, 2013.

  16. Bruno Pontecorvo press conference, 1955; quote is translation of Mafai, Il lungo freddo, p. 193.

  17. And there the collection of logbooks stayed for sixty years. In 2013, in preparation for celebrations of Bruno Pontecorvo’s hundredth birthday, some documents became available. It was at the celebration, held in Rome in September, that I met Gil and saw their content for the first time.

  18. The hydrogen in heavy water consists primarily of deuterium, whose atomic nuclei consist of a proton linked to a neutron. As there are two constituents in this hydrogen nucleus, it is sometimes referred to as H2. Tritium, which consists of a proton and two neutrons, is thus H3. “Quadium,” or H4, is a proton accompanied by three neutrons.

  19. Dubna could generate collisions between alpha particles and solid targets. Alpha particles consist of two protons and two neutrons, which offered the hope that H4, which consists of one proton and three neutrons, might be present in the debris.

  20. The material regarding H4 has no relevance other than
as an interesting dead end in the Soviets’ thermonuclear strategy. Having spent four decades as a nuclear and particle physicist, I can assert that H4 would be low on anyone’s list of interests, if it even appeared at all. If one were to ask any competent students of nuclear physics about H4, they would immediately recognize that it would probably be so unstable as to be in effect nonexistent. Basic quantum theory tells us that at most two neutrons can coexist in a relatively stable state in hydrogen isotopes. H3 (tritium) is already radioactive and unstable. A third neutron, as in H4, would have to be on a higher rung of the energy ladder. The most probable way for H4 to decay would be to release a neutron and leave tritium, which it does in less than a thousandth of a billionth of a billionth of a second.

  Bruno Pontecorvo, in 1950, was well versed in this field. It would be remarkable if this did not occur to him. Although the theory of the nuclear “shell model” is standard fare today, it was formulated only in 1948–49 by Maria Goeppert-Mayer and Hans Jensen, for which they later won the Nobel Prize. It is possible that this work was either not known or not accepted in the USSR in 1950. On balance it would seem likely that the Soviets were interested in the strategic possibility of producing “super-tritium” (H4), and the question was how to detect it. Bruno responded to this as an experimental challenge, ignoring the fact that well-established theory placed the existence of H4 in great doubt.

  21. It was during this period that stories linking Pontecorvo with uranium appeared in the Western media and in intelligence reports delivered by Western embassies. For examples, see the Daily Telegraph, March 21, 1951, and the secret report sent from Trieste to MI5 on April 13, 1951: “PONTECORVO is alleged to be directing extraction of uranium pitchblende in KAMENICE about 100 km SE of PRAGUE” (TNA KV 2/1889, memo 234).

  22. It seems implausible that the significance of this interest in fission and H4 particles could have escaped the attention of a nuclear physicist such as Bruno Pontecorvo.

  23. The alternative theories have various problems. One possibility is that he was ill and unable to work for a year, but there is no evidence for this. Marianne did fall ill, but there is no evidence that this unduly hindered Bruno’s physics career, and certainly not to the extent that he would write nothing at all in the logbooks for so long. If he spent his time gathering a team of scientists to conduct experiments, one would expect this activity to be recorded in the logs at some point. However, the entries from this period are not even sporadic; they are nonexistent. I spoke to several experimental nuclear and particle physicists, who were active half a century ago, and they found the lack of records inexplicable, unless Bruno was working on some other project during that period.

  24. One document from this period has come to light: a brief note from the Soviet Academy of Sciences, signed by Igor Kurchatov on July 27, 1951, and marked with the word “Approved.” This document refers to a “Consolidated Programme of Research Work for Installation M.” It appears to be an outline for a research program in particle physics, which later formed the core of the work reported in Bruno’s logbooks from September 1951 onward. Source: M. G. Sapozhnikov, “Seminar on B. Pontecorvo’s Life and Ideas,” JINR, Dubna, undated.

  25. Quoted in Close et al., The Particle Odyssey. p. 75.

  26. Soviet Academy of Sciences, “Report of the Institute for Nuclear Problems” [in Russian], 1951, referenced in Journal of Experimental and Theoretical Physics 29 (1955): 265–273, ref. 2; p. 129 in BPSSW.

  27. I am grateful to Gil Pontecorvo for accessing and translating this report.

  28. For example, see http://www.britannica.com/EBchecked/topic/438712/Abraham-Pais and http://www.webofstories.com/play/murray.gell-mann/68.

  29. Strange particles contain one or more strange quarks (or strange antiquarks). Particles without strangeness either have no strange quarks, or the number of strange quarks and antiquarks exactly balance, so that their individual positive and negative amounts of strangeness cancel.

  30. Mafai, Il lungo freddo, p. 177.

  31. Gil Pontecorvo interview, September 4, 2013.

  32. Mafai, Il lungo freddo, p. 192.

  33. Stella Rimington comment to author, June 14, 2013.

  34. Pincher, Treachery, chap. 55 and Chapman Pincher interview, November 13, 2013.

  35. Mafai, Il lungo freddo, p. 189; Miriam Mafai e-mail, 2012.

  36. Mafai, Il lungo freddo, p. 189.

  37. Mafai, Il lungo freddo, p. 186.

  38. Mafai, Il lungo freddo, p. 181.

  39. Stalin, who had engineered plots throughout his career, imagined conspiracies all around him and used the case of the Jewish doctors as an excuse to launch an anti-Semitic campaign. The obvious question of why these senior medical professionals, some of whom were also university professors, would commit such crimes was answered by a simple, blunt assertion: “They were agents of foreign powers.”

  40. Mafai, Il lungo freddo, p. 181.

  41. Gil Pontecorvo interview, September 4, 2013.

  42. Mafai, Il lungo freddo, p. 187.

  CHAPTER 16

  1. Mafai, Il lungo freddo, p. 192.

  2. The two conversational interviews conducted by Arnold hardly merit such a colorful description. Bruno’s reaction is more understandable, however, if he had learned in August 1950 that the FBI interest in him had resurfaced, and that the Americans were pressing MI5 for action.

  3. Quotes taken from British media reports of the Isvestia article and of the press conference, in TNA KV 2/1888.

  4. Guido Pontecorvo to MI5, in TNA KV 2/1888.

  5. The scientists’ statement (“Atomic Energy Control,” The Times, January 21, 1947) was mentioned in a speech to the UN Security Council by Andrei Gromyko, the Soviet Union’s deputy minister of foreign affairs. Quoted in Laucht, Elemental Germans, chap. 6.

  6. Picture Post, February 18, 1950: “British scientists answer the question all world is asking: what should be done about the hydrogen bomb?”; Daily Mirror, March 25, 1950, front page: “Scientists jib at H bomb jobs.”

  7. Years later, after the Krogers had been arrested in the UK, released, and returned once again to the USSR, Morris Cohen/Peter Kroger happened to run into George Blake, another infamous KGB spy, in Moscow. They arranged to meet. The authorities immediately ordered that no such meetings were to take place.

  8. Mafai, Il lungo freddo, p. 192.

  9. Bruno won the Stalin Prize in 1953. The cash value of the prize in 1950 was about a thousand times a typical monthly income. In other words, the winner received, in effect, a lifetime’s salary in advance. Life in the Soviet Union had been hard following the war, and although by the 1950s food was plentiful, there was “no variety of other goods” (Sacha Adriana interview, January 23, 2012). In addition, the award also gave the recipient access to special shops, which under the circumstances would have been invaluable. As a leading Academician and member of the party, Bruno also had access to foreign goods, theater tickets, special hotels, and other privileges off limits to the majority of citizens.

  10. Reports of press conference, for example Mafai, Il lungo freddo, p. 191 et seq.

  11. Gil still qualifies for a UK passport; it was Bruno that crossed the line and took his family with him. Gil Pontecorvo interview, August 25, 2011.

  12. Mafai, Il lungo freddo, p. 275.

  13. Mafai, Il lungo freddo, p. 147.

  14. Mafai, Il lungo freddo, p. 205.

  15. Ioffe, “A Top Secret Assignment”; Bruno Ioffe interview, December 2012.

  16. Semen Gershtein in BPSSW.

  17. Its proton kinetic energy was 600 MeV or 0.6 GeV. At CERN’s synchrotron in 1959, the energy was 28 GeV.

  18. Nino Zichichi interview, June 30, 2013.

  19. Gian Carlo Wick, as reported in Mafai, Il lungo freddo, p. 212; Ugo Amaldi interviews, April 18, 2013, and September 12, 2013.

  20. Mafai, Il lungo freddo, p. 212; Miriam Mafai interview, March 2012.

  CHAPTER 17

  1. Jack Steinberger, quoted in U. Dore and L. Zane
llo, “Bruno Pontecorvo and Neutrino Physics,” available at http://arxiv.org/pdf/0910.1657.pdf.

  2. Bruno Pontecorvo is one of a select group of scientists who have an equation inscribed on their tomb or memorial stone. Ludwig Boltzmann’s headstone in Vienna records the thermodynamic passage from order to decay. Paul Dirac’s eponymous equation for the electron is set in stone in London’s Westminster Abbey.

  3. The Cowan and Reines discovery paper is available at http://www.sciencemag.org/content/124/3212/103.

  4. In the acknowledgments at the end of the paper, Pontecorvo thanks Pomeranchuk for a comment about an effect of relativity. This appears to be one of only two cases where he and Pomeranchuk had any discussion about fundamental physics; the other dealt with strange particles.

  5. Venedict Dzhelepov in BPSSW.

  6. Given that the K-zero turns into an anti-K-zero through a two-step process, what would the analogous mechanism be for a neutrino? Bruno’s ideas on this subject seem to have matured when he considered the fact that an electrically neutral atom can be made from a negatively charged electron and a positively charged muon; he realized that a negatively charged muon accompanied by a positron forms a similar system. In 1947, he had showed that a muon decays into an electron and two neutrinos—actually, he now realized, one neutrino and one antineutrino. This implied that the atom (made of a positive muon and an electron) could convert into a neutrino and an antineutrino. In turn, this latter pair of neutral entities could materialize as a negative muon and a positron. The result would be the conversion of an atom into an anti-atom. This does not happen in reality, for reasons that became clear a few years later. However, this idea was an important step in the development of Bruno’s thinking about neutrinos. In theory, the process described above could have allowed a neutrino to convert to an antineutrino, or vice versa.

  7. Bruno Pontecorvo in Journal of Experimental and Theoretical Physics 36 (1959): 1615. Quotation taken from English-language version, “Universal Fermi Interaction and Astrophysics,” reprinted in BPSSW, p. 164.

  8. Schwinger combined relativity and quantum theory and applied them to QED (quantum electrodynamics). He won the prize in 1965 for work done in 1947.