The first war of physics

A review of Atomic the First War of Physics and the Secret History of the Atomic Bomb, 1939–49, by J. Baggott, London, Icon Books, 2009, 576 pp., £20.00 (hardback), ISBN 978 184831 044 5. Scope: history of science. Level: general reader.

On 10 April 1945 Moscow Centre sent a coded message in Russian to Leonid Romanovich Kvasnikov, its man in New York. When translated it read 1:

ChARL’Z's information 2/57 on the atomic bomb (henceforth “BAL …” is of great value. Apart from the data on the atomic mass of the nuclear explosive and on the details of the explosive method of actuating “BAL …” it contains information received for the first time from you about the electromagnetic method of separation of ENORMOZ. We wish in addition to establish the following:(1)For what kind of fission – by means of fast or slow neutrons –

This message was recorded by the US authorities in its VENONA project 2 but not decrypted for four years. It shows that the Soviet spy codenamed CHARLES [ChARL'Z in Russian] knew the most secret information at the heart of the Manhattan Project, the attempt by the US together with Britain and Canada to build an atomic bomb during the second world war before Germany built one. In particular, CHARLES showed that he knew not only the critical mass of Pu239 but also the implosion method using explosive lenses that was needed to detonate plutonium (because of the presence of spontaneously fissile Pu240, the gun mechanism used in U235 whereby a critical mass is obtained by firing a U235 bullet into a nearly critical U235 cylinder cannot be used in plutonium) and moreover he knew details of the methods used to separate the fissile uranium isotope U235 from the predominant isotope U238, which does not fission with slow neutrons. ENORMOZ started as the code word for the enormous gaseous diffusion isotope separation plant at Oak Ridge in Tennessee. It was then used to describe U235 itself and sometimes the whole Manhattan Project. BAL was probably short for BALLON (balloon).

The number of scientists in the Manhattan Project who knew in detail about the work on critical mass calculations, uranium isotope separation and plutonium implosion was very small. One of those who did was Rudolf Peierls. He was the senior British theorist at Los Alamos; his memorandum 3 with Otto Frisch of March 1940 on the critical mass of U235 led directly to the precursors of the Manhattan Project in Britain and the United States; he had written (with Klaus Fuchs) one of the first British papers on uranium isotope separation 4 and he was section head of T-1 responsible for implosion dynamics at Los Alamos 5. Furthermore, his wife Genia was Russian. He was an obvious candidate to be CHARLES.

Another message from Moscow to New York dated 16 November 1944 6 was decrypted to read

On ARNO's last visit to CHARLES’ sister it became known that CHARLES has not left for the ISLAND but is at Camp 2. He flew to Chicago and telephoned his sister ….

The ISLAND was code for Britain and Camp 2 was Los Alamos (Camp 1 was Oak Ridge). So CHARLES was a member of the British mission at Los Alamos which numbered 19 men 7. Those who knew about critical mass calculations and implosion dynamics would have been in the Theoretical Division. When Peierls had been asked by Hans Bethe, the head of the Theoretical Division to come to Los Alamos, Peierls accepted provided that he could bring Fuchs and Tony Skyrme with him. The three, of them were already working on the gaseous diffusion method of isotope separation and they had been attached to the Kellex Corporation in New York which was designing Oak Ridge before going on to Los Alamos in 1944. Peierls, Fuchs and Skyrme were the only members of the British mission in the Theoretical Division in November 1944 8. So the number of suspects could be narrowed to just three, of whom Fuchs and Peierls were the principal suspects since they were dodgy refugees: Fuchs had a communist past while Professor and Mrs Peierls had visited the Soviet Union in 1937. Moreover, they both had sisters living in the US! Fuchs' sister Mrs Kristel Heineman lived in Cambridge, Massachusetts, while Peierls' sister Mrs Annie Krebs lived in New Jersey. A top secret cable from the British Embassy in Washington to Arthur Martin of MI5 dated September 21 1949 9 states that the FBI's ‘first priority is to identify Peierls’ sister.' It goes on ‘we still feel that Fuchs is a much more likely candidate’.

What put the identification of CHARLES as Klaus Fuchs beyond any reasonable doubt was that Fuchs had visited Fermi's Metallurgical laboratory in Chicago in an official capacity in late 1944 while Peierls remained at Los Alamos. Furthermore, a cable from Moscow dated 15 June 1944 10 referred to a report MSN-12 having been received from REST: the codename REST became CHARLES in October 1944. The MSN series of reports were written by the scientists in the British mission while they were working in New York on gaseous diffusion and MSN-12 was written by Fuchs.

Although this was all known to the British and American intelligence services, it was all secret and could not be made public without revealing the monitoring of diplomatic cables. Nor was evidence so obtained admissible either in English or US courts. So the public case against Fuchs at his trial was totally based on his confession when his interrogator William Skardon confronted him with details of his Soviet contacts.

Jim Baggott's Atomic: the First War of Physics and the Secret History of the Atom Bomb: 1939–40 covers all this ground. It is unusual in that in addition to the now well-known histories of the Manhattan Project 11, the Soviet nuclear programme 12, and the American H-bomb programme 13 it also describes the early German nuclear effort and the part that Soviet espionage played in the development of its nuclear weapons. Baggott tries to limit his story by confining it to the decade 1939–49 so ending the main narrative with the arrest of Fuchs in 1949 and the explosion of the first Soviet fission bomb Joe-1 the same year.

But in my opinion he relies too much on the work of others in all these areas without necessarily understanding the physics or the context. As he says himself in his preface ‘I have happily climbed on the shoulders of their scholarship’. But reliance on secondary sources is always dangerous. Especially when as here he states that he has drawn on those ‘sources of historical documents that can be found online’. The report MSN-12 referred to in the cable of 15 June 1944 can be read in its entirety at the Public Record Office at Kew 14 in London as can the personal files of both Peierls and Fuchs but none of these are available online. What can be found online are the VENONA decrypts of the KGB traffic between Moscow and the west 2.

Alan Nunn May, who was arrested in 1946 in London, convicted and sentenced to 10 years in prison (Fuchs got 14 years) is described by Baggott as ‘one of the most important of the spies identified by Gouzenko’. Gouzenko was a cipher clerk in the Soviet Embassy in Ottawa who defected when he was recalled. A document in his possession identified May who was working at the reactor project at Chalk River. May had contacted the Soviets in early 1945 and had offered help: the USSR was after all a major ally at the time in the war against Nazi Germany. In May's defence at his trial Gerald Gardiner, the future Lord Chancellor in the Labour government in the 1960s, said that May had been influenced by a statement by Winston Churchill that Britain had offered Russia any technical knowledge likely to have been of use to them. May had given his Soviet contact at the latter's request about a milligram of slightly enriched uranium oxide and one-tenth of a milligram of U233, which like U235 is fissile. This material was useful but hardly of major importance. Margaret Gowing and Lorna Arnold record that May ‘had no contact with weapon information’ and that Sir Wallace Akers, former Director of the British wartime nuclear project ‘was flabbergasted by the sentence and general attittude of the judge’. Maybe Baggott hadn't read Gowing and Arnold's Independence and Deterrence Britain and Atomic Energy 1945–52, Volume 2 15, where this is discussed: only Volume 1 is listed in the bibliography.

Then there is Ted Hall, who worked at Cambridge on biophysics from 1962 until he died in 1999. A decrypt of a cable dated 12 November 1944 actually identified him 16:

‘BEK visited Theodore Hall [TEODOR KHOLL] 19 years old, the son of a furrier. He is a graduate of Harvard University ….At the present time H. is in charge of a group at Camp 2. H. handed over to BEK a report about the Camp and named the key personnel employed on ENORMOZ.’

It is still unclear why Hall was never charged. In later cables he was assigned the codename MLAD and passed further details of the work at Los Alamos to his handler. His contribution was not as important as that of Fuchs but it was substantially more important than that of May given that he passed on information about the various sites of the Manhattan Project and what work was being done in them; a description of the four methods of enriching uranium being pursued at the time, and information about the scientists working on the project 17. Baggott shows the difficulty of writing about a field with only partial understanding of the subject matter when he says ‘a cable dated 23 January 1945 indicated that MLAD (whose codename had by then changed to YOUNG) … ’. In fact, MLAD means ‘young’ (or rather ‘young man’) in Russian.

Baggott's grasp of the physics is reasonable, at least where fission weapons are concerned, although he is occasionally inaccurate. He writes of the introductory lectures given by Robert Serber in April 1943 to the new arrivals at Los Alamos that ‘The critical mass of U-235 had by this stage been fixed at around 200 kilos’, which was ‘impractical for a weapon to be dropped from an aeroplane’. Baggott then says that with a surrounding tamper ‘this brought the critical mass down to 15 kilos’ and for plutonium to ‘just 5 kilos’. Serber did indeed give the figures of 15 kilo for U235 and 5 kilo for Pu239 with a thick uranium tamper but the 200 kilo figure comes from what he calls ‘the simplest estimate of minimum size of bomb’. Serber then explains that ‘the value of the critical mass is, however, considerably overestimated by the elementary diffusion theory’ 18 which he used in the calculation. A better calculation of the critical mass of a sphere of U235 without tamper would have given about 60 kg even in 1943.

On thermonuclear weapons he is muddled. He doesn't give any indication of understanding the physical principles of the Sakharov ‘sloika’ or ‘layer cake’ known in the west as Joe-4 to which he refers. The ‘layer-cake’ involves layers of light and heavy elements: the light elements were lithium and deuterium in the form of lithium-6 deuteride and the heavy layer was U238. He explains correctly that lithium-6 in the presence of energetic neutrons would produce tritium which could then undergo DT interactions. But the crucial point of Sakharov's ‘First Idea’ is that a layer of light elements between two layers of heavy elements in equilibrium at a high temperature would lead to compression of the light atoms by the heavy atoms thus enhancing the probability of fusion. For example if a layer of deuterium is surrounded by two layers of uranium then at temperatures T of millions of degrees the material becomes fully ionised and the pressure p = nkT, where n is the total concentration of nuclei and electrons. But the uranium nucleus is surrounded by 92 electrons while the deuteron nucleus only has one electron. At the interface between deuterium and uranium the pressures and temperatures must be equal so that the concentration of deuterons n _D and the concentration of uranium nuclei n _U are related by 19

This is known as ‘ionisation compression’ but it is better known in Russia as ‘sakharisation’ (‘sakhar’ means sugar in Russian). This discussion does not include the contribution of radiation to the pressure–temperature equation but it is easily shown that this does not change the result for the compression.

The First Idea dates from 1948 so is within Baggott's time frame. He goes on to discuss the Super design which Edward Teller hoped would become the US first H-bomb. There was a conference on the Super at Los Alamos in 1946 in which British scientists including Fuchs participated. With the advent of the first electronic computers later in the decade it became clear that the thermonuclear fuel in the Super could not ignite unless a few kilograms of tritium were used while the annual US production rate of tritium at the time was measured in tens of grams 20. The ignition problem was solved in the US by Ulam, Teller and others in the early 1950s which should have been outside Baggott's timeframe but he discusses it in the Epilogue together with the Soviet test of Joe-4 in November 1953. Again it is not clear that he understands the issues involved in Ulam and Teller's work or the corresponding work by Sakharov and Zel'dovich which led to the successful Soviet test of a two-stage thermonuclear weapon in 1955. He also has a chapter entitled ‘Proliferation’, yet he only discusses the Soviet programme although the British decision to produce nuclear weapons dates from 1947.

To be fair, Baggott tells a good story. Mark Walker, the distinguished historian of the German nuclear project is quoted on the dustcover that he ‘particularly likes the way Baggott has been able to weave the science, “grand-scale” politics and espionage together into one compelling narrative’. A colleague who prefers to be nameless but is very familiar with the issues told me that ‘This is a popular book, meant for a general audience, so that its derivative nature is to be expected. It would be over-ambitious if it claimed to be a thorough academic account, or to make an original contribution to our understanding of this period and these issues but it does not. I think that this book will fill a useful niche, and although it is more sensational than I personally would like, and he does dwell on the espionage more than I would have, it is a good synthesis of the basic facts, the politics of the time, and the spy stories that so many people are interested in. It is this synthesis, more than any particular chapter, that I think is impressive.’ But my own conclusion is that the deficiencies in the account pile up so readers should beware.

I started this review with the Soviet spy REST/CHARLES, who was soon identified as Fuchs but Rudolf Peierls was also under suspicion. Peierls in fact came to the attention of Special Branch as early as April 1938 when he returned from a visit to Denmark and immigration officials at Harwich noticed that he had a Soviet visa in his passport. His status as Professor of Mathematical Physics at the University of Birmingham meant that the matter was not pursued but it was entered into his personal security file 21. (Peierls had visited his in-laws in Leningrad in 1937). Official suspicion about him was further aroused in October 1943 when Niels and Aage Bohr visited Birmingham. Peierls took them to the Aliens Registration Office to register their stay under the wartime residence regulations then in force. The Birmingham Police thought it very odd that Peierls knew both the Bohrs. They reported to the Security Services that ‘it seems somewhat strange that two men, who have arrived in the country so recently, should be associated with Peierls’ especially given that ‘Peierls was formerly German and acquired British nationality by certificate of naturalisation’ 21. (Peierls had been a frequent visitor to the Institute of Theoretical Physics in Copenhagen in the period 1937–39 when he was collaborating with Niels Bohr on the compound nucleus.)

During 1945 and 1946 some progress was made in decrypting the VENONA messages 22 and Gouzenko defected so the British and American security services became aware of the extent of Soviet penetration of the Manhattan Project. This led to a review of the personnel who had taken part with emphasis on the refugees and on 23 January 1947 the Home Office was informed by the Security Services that both Fuchs and Peierls were to be investigated and their mail opened ‘to get a better idea of the circles in which Fuchs and Peierls move and the contacts they make’. The memo stated that ‘Both are Germans of the refugee type’ 21. This was more than a year after The Times published a prominent article entitled ‘Research on Atom Bomb: British Achievements’ 23 which drew attention to Peierls' pioneering work in 1940 on fission in uranium 235 on which the Manhattan Project was based.

In September 1949 after most of the VENONA messages had been decrypted, Fuchs was positively identified as REST/CHARLES. A note from the Security Services to the Prime Minister under the heading ‘Investigation into the activities of Emil Julius Klaus Fuchs’ stated that ‘All the usual methods of Security Service investigation have been brought into use in Harwell itself (Fuchs headed the Theoretical Physics Division at Harwell) …. By the same technical methods informaton is being obtained about the activities in Birmingham of Professor R E Peierls of Birmingham University, Fuchs’ close friend and scientific colleague'. Orders were made to intercept the mail of both Fuchs and Peierls and to tap their telephones 9. So when Peierls arrived back at Prestwick Airport from New York in October 1949 Special Branch kept an eye on him. ‘He was dressed in a shabby waterproof trench coat with belt; dark grey soft hat with black band – brim turned up all round, dark grey flannel trousers, brown shoes with crepe rubber soles’ 9 it noted. Fuchs confessed and was charged in March 1950: he pleaded guilty.

Finally the British security services were able to conclude that ‘there is no substantial doubt about the loyalty of Prof. Peierls’ 24 and Peierls' security file was closed in 1953 25. Yet doubt persisted in some quarters. Peierls was too eager to visit the Soviet Union, as he did when he went to a conference on high energy nuclear physics in Moscow in 1956. In the fevered atmosphere of Washington in the mid-1950s where Senator McCarthy's Committee on Government Operations held its hearings, even Robert Oppenheimer, the founding Scientific Director of Los Alamos was held to be a security risk. So a friend and colleague of both Oppenheimer and Fuchs with a Russian wife who visited Moscow was clearly also a security risk. Hence, in 1957 the US authorities informed Britain that no US classified information could be shown to Peierls 25 who in response gave up his Harwell consultancy.

Peierls moved to Oxford to become Wykeham Professor of Theoretical Physics in 1963. As at Birmingham 26 years earlier he set out to create a major centre of theoretical physics involving all branches of the subject. He arranged for Richard Dalitz to join him from Chicago as Royal Society Research Professor to lead the particle theory group and Dalitz, together with his students and post-docs, soon established Oxford as the world leader in research on the quark model. Peierls became actively involved with university teaching reform and the Pugwash movement of scientists which was working to limit the spread of nuclear weapons. He was instrumental in getting Landau and Lifshitz' massive Course of Theoretical Physics, on which a generation of Soviet physicists had been reared, to be published in English. He was also a member of the Editorial Board of Contemporary Physics. He was knighted in 1968 and died in 1995 aged 88.

That should have been the end of his involvement with Fuchs and the spy saga. But it was not to be as Baggott indicates in his Epilogue. For it was not only the US security services who never forgave Peierls for his association with Fuchs and his friendly relationship with Soviet physicists. The British security services also contained xenophobic elements who were convinced that Peierls had been a Soviet spy all along. After all, REST/CHARLES was not the only spy involved in the Manhattan Project who featured in the VENONA transcripts. There were others who were not identified. One was called first FOGEL and then PERS. According to the message from New York to Moscow of 16 June 1944 26

By the same post [8 June] were despatched two secret plans of the layout of ENORMOZ plant received from FOGEL.

The message of 13 December 1944 27 read

PERS [text not decoded] Camp 1. Our proposal [text not decoded] not to give any more on ENORMOZ.

On 29 May 1999 an article appeared in The Spectator entitled ‘Sir Rudolf and Lady Spies’ by Nicholas Farrell 28 who claimed that FOGEL/PERS was Rudolf Peierls and that another unidentified spy codenamed TINA based in London was Genia Peierls. According to Farrell this explained why Peierls' security clearance at Harwell was withdrawn. This claim could not have been published while Rudolf and Genia Peierls were alive since they could then sue for libel. Farrell called the Peierlses ‘the best candidates to be the British Rosenbergs’ (Ethel and Julius Rosenberg were executed for espionage in 1953). Farrell provided scant evidence for his claim, other than quoting anonymous ‘British security service sources’. His only ‘evidence’ seems to have been that Peierls' autobiography was called Bird of Passage and that Vogel was German for bird.

Dick Dalitz and I knew Peierls and his wife well and were convinced this was all nonsense. It soon became clear following an article in Physics World 29 that Farrell had based his article on material given him by the spy writer Nigel West (the pen name of Rupert Allason), who has good contacts with the security services and had just written a book 30 on VENONA. So Dalitz and I wrote a rebuttal to The Spectator 31 pointing out that Genia was in Los Alamos in summer 1945 when TINA was in London and that FOGEL/PERS had been described in a recent book The Haunted Wood by Allen Weinstein and Alexander Vassiliev based on KGB documents as ‘a young US engineer and communist party member’ 32. There was in fact nothing in VENONA to connect FOGEL/PERS with the British mission. We also pointed out that according to The Haunted Wood TINA worked for the British Association on Non-Ferrous Metals, an organisation charged with uranium procurement. Dalitz and I then wrote a more detailed letter to The Spectator emphasising that Peierls was in Los Alamos when FOGEL/PERS was in New York and that there was no reason to associate FOGEL/PERS with Los Alamos, which was Camp 2, whereas FOGEL/PERS seems to have been involved with Camp 1, that is Oak Ridge. The Spectator did not publish our second letter so Dalitz submitted an adapted version to Physics World 33. Farrell may or may not have known about VENONA but he was certainly ignorant about the Manhattan Project: he states as fact that FOGEL ‘supplied them [the Soviets] with a detailed map of Los Alamos containing precise information about who was working where and on what’. But the message of 16 June 1944 referred to ‘two secret plans of the layout of ENORMOZ plant received from FOGEL’. ENORMOZ meant Oak Ridge and/or The Manhattan Project generally, which involved many plants not just Los Alamos. Indeed, Ted Hall had listed eight of them in the VENONA cable of 26 May 1945 17.

I was able to identify TINA in September 1999 in a letter to The Times 34 following Melita Norwood's confession that she had been recruited to work for Soviet intelligence while she was working at the British Association on Non-Ferrous Metals. It was clear that she was TINA.

But who was FOGEL/PERS? That has remained a mystery until now. Alexander Vassiliev was joint author of The Haunted Wood which was part of an official US–Russia project to open up KGB files to historians. But that soon collapsed. Vassiliev, however, noted down the material he was inspecting, moved to Britain and eventually arranged for his notebooks to be shipped to him. He has just now published, together with John Earl Haynes and Harvey Klehr, Spies: The Rise and Fall of the KGB in America 35 which is based on those notebooks. At last FOGEL/PERS is identified.

FOGEL/PERS was not a member of the British mission at Los Alamos nor was he based at Los Alamos, just as Dalitz and I had argued. He was not even a physicist. He was an American engineer who worked for Kellex in New York, which was designing the enrichment plant at Oak Ridge. He was certainly not Rudolf Peierls. His name was Russell McNutt and he worked on the design of the water-coolers installed at Oak Ridge. He declined requests from his handlers to move to Oak Ridge and obtained a job with Gulf Oil, eventually becoming a vice-president of the company. He died last year.

Baggott's book can only be called a tertiary source as it is based on secondary sources. Spies is a secondary source but it is at least written by someone who has had access to primary sources. For example this is how Fuchs first met his courier:

Rendezvous in NY – to establish a connection with REST. Meeting place..at the door of Henry St settlement, in Henry St, Downtown, East End, Jewish Quarter, NY. Time at 1600 on the 1st and 3rd Sat. of every month, starting in Jan. 44. Recognition signals: REST will be holding a green book and a tennis ball. Our man will be wearing gloves. He will be carrying a third glove in one of his hands.

OUR MAN: What is the way to China Town?REST I think China Town is closed at 5 o'clock.

That is a real-life glimpse into a vanished secret world, but one which is familiar to devotees of John le Carré.

© 2010, Norman Dombey