Soviet Hydrogen Bomb

In 1938 Sergei Kapitsa had been instrumental in freeing the eminent physicist Lev Landau after he had been imprisoned for adding his name to a leaflet that accused Stalin of hijacking the revolution.

During the years of the Cold War and the Iron Curtain, the ideological confrontation and the psychological pressure reached such a level that the possibility of a nuclear intervention was perceived in the USSR and the USA nearly as inevitability. Meanwhile, nuclear scientists began creating even more dangerous and destructive thermonuclear weapons. One of the “instigators” of this race was the outstanding American physicist of Hungarian origin Edward Teller. Igor Kurchatov, as the head of the Soviet atomic project in general, was also responsible for the development of the hydrogen, or thermonuclear bomb. The engineering of all versions of nuclear weapons, the theoretical and experimental verification of the construction was done at KB-11 headed by Y.B. Khariton. This issue, starting in 1948, was also laid upon I.E. Tamm, V.L. Ginzburg, A.D. Sakharov, and Y.B. Zeldovich.

In the summer of 1945, atomic scientists in the United States started talking about the possibility of creating a thermonuclear weapon. Part of the physicists in Los Alamos, including E. Fermi, switched to researching this problem. In September 1945, agents of the NKVD were able to extract the lectures given by Fermi to Los Alamos specialists. They contained important initial ideas about the initial version of a thermonuclear bomb, the so-called "classic super". More detailed information was received in March 1948. It reflected a higher level of development of this problem, in particular, it contained an interesting hint of the possibility of the formation of tritium from lithium irradiated by neurons during a thermonuclear reaction in the charge of a hydrogen bomb.

In 1947, Soviet intelligence received documents, which talked about lithium as a component of thermonuclear fuel. In March 1948, materials were obtained from the physicist Fuchs, who worked for Soviet intelligence, describing the two-stage design of the charge of a thermonuclear bomb operating on the principle of radiation inplosion. The principle of operation of the initiating compartment of the system was described and experimental and theoretical data related to justifying the operability of the project are presented. April 20, 1948 this information was sent to Stalin, Molotov and Beria.

The beginning of the first work on the thermonuclear program in the USSR dates back to 1945. Then I.V.Kurchatov received information about the research being conducted in the United States on the thermonuclear problem. They were launched on the initiative of Edward Teller in 1942, under the program Alarm Clock, the goal - the creation of a hydrogen bomb megaton class based on lithium-6 deuteride. In 1949, after the successful testing of the first Soviet atomic bomb, the Americans forcibly increased their strategic nuclear forces. The development of thermonuclear weapons became increasingly important for the Soviet Union.

Toward the end of June 1948, the illustrious Igor Tamm invited Sakharov and another student, Yuri Romanov, to his office, where he broke “startling news.” Orders had come down from the very top, the Council of Ministers and the Party Central Committee: Tamm had been appointed to head a group charged with exploring the possibilities of buildinga thermonuclear weapon. Sakharov and Romanov would be a part of that group. In 1948, when Sakharov went to work on the H-bomb project, the United States had fifty-six atomic weapons, the Soviet Union not one.

What Fermi had called the “superb physics” and Oppenheimer the “technically sweet” was not Sakharov’s chief motivation. “What was most important for me at the time, and also, I believe, for Tamm and the other members of the group, was the conviction that our work was essential.” The work on a thermonuclear weapon was a continuation of the war, the patriotism of survival. Hans Bethe, the German e´migre´ physicist who headed the Theoretical Division at Los Alamos, said of the Manhattan Project: “We all felt that, like the soldiers, we had done our duty.” The Russians were more literal. Kurchatov told Sakharov and the other physicists that they were “soldiers” and often signed his memos “Soldier Kurchatov.” Sakharov accepted the designation unhesitatingly and unequivocally, considering himself a “soldier in this new scientific war.” There was also a personal dimension to thermonuclear research for Sakharov, who saw it as a “possibility to prove what one can do, above all to oneself.”

A series of insights now constellated into a workable idea, soon known as the “First Idea.” Sakharov proposed an “alternate design for a thermonuclear charge that differed from the one pursued by Zeldovich’s group in both the explosion’s physical processes and the basic source of the energy released.” Nicknamed the “layer cake,” Sakharov’s idea proposed using a spherical assembly of concentric shells with an A-bomb as the ignition, tamped by a layer of uranium 238, which retards the expansion so that more reaction can occur. The atomic weapon kicks off a thermonuclear reaction in the surroundingfusion fuel, composed of lithium deuteride and lithium tritide. That in turn causes a fission reaction in another layer of uranium 238. Only about 20 percent of the yield of such a device would be truly thermonuclear, and the reaction is usually described as fission-fusion-fission. The same idea (nicknamed the “Alarm Clock”) had occurred to Edward Teller in 1946.

In 1948 A.D.Sakharov put forward the basic ideas of the construction of a hydrogen bomb RDS-6. After that, the development of the bomb went in two directions: "puff / Sloyka" (RDS-6S), which implied an atomic charge surrounded by several layers of light and heavy elements, and a "pipe" (RDS-6T), in which a plutonium bomb was immersed in liquid deuterium. The United States developed similar schemes.

For example, the "Alarm clock" scheme, which was put forward by Edward Teller, was an analog of the "Sakharov" puff, but it was never used in practice. But the scheme "Trumpet", over which scientists worked for so long, turned out to be a dead-end idea. After testing the RDS-1 bomb, the main efforts were concentrated on the "Sloyka" variant. The "Sloyka" scheme, however, did not have the prospects of scaling the explosion power over a megaton.

In the fall of 1948, after the “First Idea” was accepted by the Tamm group, Sakharov received a significant raise in pay and an invitation from a KGB general Sakharov to join the Communist Party. Sakharov declined. Suddenly surprisingly political, he cited his misgivings about the “arrest of innocent people and the excesses of the collectivization campaign.”

The Installation had originally been named Arzamas-60 because of the sixty-kilometer distance from Sarov, but that precision was considered a breach of security and the name was changed to 16, which signified absolutely nothing.

The result of the discussion on the possibility of creating a hydrogen bomb was Resolution No. 1989-73 of the Council of Ministers on the Supplementation of the Work Plan for KB-11. In particular, it obliged the KB-11 to carry out, before June 1, 1949, with the participation of the Physics Institute of the Academy of Sciences of the USSR, theoretical studies on the initiation and combustion of deuterium and mixtures of deuterium and tritium.

As David Holloway observed in Stalin and the Bomb: “The building of the atomic bomb was the kind of task for which the Stalinist command economy was ideally suited. . . . It was a heroic undertaking for which the resources of the country could be mobilized, including the best scientists and industrial managers, as well as the slave labor of the Gulag. The project was a curious combination of the best and the worst of Soviet society — of enthusiastic scientists and engineers produced by the expansion of education under Soviet rule, and of prisoners who lived in the inhuman conditions of the labor camp.”

On one subject there was no ambiguity, especially after Truman’s announcement of the American H-bomb project: Stalin wanted thermonuclear weapons and wanted them fast. In early March 1950 the grace period of requests, invitations, and visits came to an abrupt end — Sakharov was ordered to move to the Installation “without delay”.

Sakharov had devised the “First Idea,” which had been significantly supplemented by Vitaly Ginzburg’s “Second Idea” — that lithium deuteride in the form of a solid chemical compound be used as the thermonuclear fuel. Now, Sakharov and Zeldovich had co-sired a “Third” — “radiation implosion,” using the x rays generated by the fission of an atomic bomb to compress the thermonuclear fuel and yield more fusion.

After the arrest (or murder?) of Beria, atomic scientists were left without leadership. Previously, only Beria and Stalin stood above them, and party bosses were mostly in a pleasant ignorance. Ya.K. Golovanov wrote: "In all the crucial tests, Lavrentii Pavlovich, as a rule, was present, and here it was necessary to make the first explosion of the newly created hydrogen bomb, but there is no chief and no instructions are given to this account. All, however, understood that the impending test - an act not only scientific and technical, but also political and to show amateur performance here is impossible.

Malyshev and Kurchatov flew to Moscow. "When Malenkov heard from them about the impending trial, he was extremely surprised: about any hydrogen bomb the first person in the state knew nothing. Georgii Maximilianovich called Molotov, Voroshilov, Kaganovich, but they also did not really know anything, they "heard with the edge of their ear". And not to the bomb was the rest: events much more important shook the upper floors of power. Malenkov had to decide what to do-he had no one to ask. After a small meeting, a permit for the trial was received."

A decade of increasingly sophisticated Soviet testing of nuclear devices and weapons included the 1958 series, two series of intensive tests in 1961 and 1962, and two years of testing underground since the Partial Test Ban Treaty was signed in August 1963.

The Soviets had a family of thermonuclear (TN) weapons responsive to the present needs of their strategic attack and general purpose forces. Soviet Long Range Aviation and the Rocket Forces had a large number of older TN Weapons in the low megaton range based on the results of the tests conducted in 1958 and earlier. Weapons based on the 1961 and 1962 test series probably began to enter stockpile in 1964, and were being produced in significant quantities, and continued to be produced in order to replace older weapons still in the strategic attack forces stockpile.

These new weapons generally represented significant improvements over the entire weapons spectrum, and probably included some high yield (over ten MT TN wea ons for delivery by both aircraft and missiles.

CIA believed as of 1966 that a Threshold Treaty would impose prohibitive restrictions, beyond those of the Partial Test Ban, only for developingr weapons which might need new warheads of very high yield. If the development of such weapons had a sufficiently high priority the Soviets might conduct tests virtually certain to violate the treaty, in the belief that the violation could not be proved against them. As few as one or two such tests a year could be of significant aid to their military programs.

The Soviets had a variety of relatively large implosion fission weapons, which were still in stockpile in large numbers for tactical missie and rocket forces, for tactical aviation, for general purpose uses by the Soviet navy, and for SAM forces. As a result of the 1961-1962 tests the Soviets'were able to develop imprved fission weapons. Most of the newer fission weapons entering the Soviet stockpile in the mid-1960s were these improved low-yield Weapons.

Prior to the Partial Test Ban Treaty the Soviets had largely fulfilled their basic requirements for multimegaton TN weapons and for iission weapons. Theyv may still have a requirement for TN warheads in the submegaton and low megaton range, e.g., for the SS-ll. This requirement could be fulfilled under the Partial Test Ban, and probably would be fulfilled before the Soviets acceded to a Threshold Treaty. Under the Partial Test Ban, the Soviets conducted tests yielding up to 450 KT. Some of the tests yielding around 50 KT and higherwere probably directed toward development of TN weapons.

Several tests yielding 30 KT or less have been detected, especially during 1966; these could have been oriented toward development of either fission or TN weapons. Some weapons based on the underground tests of 1964-66 would start entering stockpile in 1967, and would be available for systems being deployed over the following several years.

Most of the thermonuclear tests were held at Novaya Zemlya, where the Soviets were probably able to instrument only for the basic diagnostic information required for development of TN weapons. Most of the Soviet fission devices were tested at Semipalatinsk. The Soviets conducted extensive tests of the effects of nuclear bursts on military equipment and structures. They clearly had ample opportunity to discover the same important nuclear effects which the US discovered.

Analysis of Soviet publications and classified manuals showed that the Soviets had acquired effects data of sufficient scope and quality on air, surface, under- water, and underground bursts to be adequate for planning and executing most military operations. Unclassified articles showed that they are aware of the transient radiation effects on electronic equipment (TREE). They were aware of the vulnerability of US missile guidance systems to these effects.

The Soviets have also shown that they understand the electro-magnetic pulse (EMP) phenomena produced by nuclear explosions, and they may have instrumented a number of low-yield surface tests to measure the EMP effect on military systems and communications equipment. Although the Soviets were probably aware of the EMP vulnerability of ICBMs and silos, it was doubtful that they have conducted tests of the surface EMP effects of high yield weapons.