Abram Isaakovich Alikhanov (; born Abraham Alikhanian; 8 December 1970) was a Soviet experimental physicist of Armenian origin who specialized in particle and nuclear physics. He was one of the Soviet Union's leading physicists.
Before joining the Soviet atomic bomb project, Alikhanov studied X-rays and cosmic rays. Between 1945 and 1968, he directed the Institute for Theoretical and Experimental Physics (ITEP) in Moscow, which was named after him in 2004. He led the development of both the first research and the first industrial heavy water reactors in the Soviet Union. They were commissioned in 1949 and 1951, respectively. Alikhanov was also a pioneer in Soviet accelerator technology. In 1934, he and Igor Kurchatov created a "baby cyclotron", the first "cyclotron" operating outside of Berkeley, California. He was the driving force behind the construction of the 70 GeV synchrotron in Serpukhov (1967), the largest in the world at the time. His brother, Artem Alikhanian, was based in the Armenian SSR and led the Yerevan Physics Institute for many years.
Early life Alikhanov was born Abraham Alikhanian to Armenian parents on in Elizavetpol, a city then part of the Russian Empire and now part of Azerbaijan. His mother, Yulia Artemevna (), was a housewife, while his father, Isahak Alikhanian (d. 1925), was a railroad engineer in the Transcaucasus Railway. Abraham's younger brother, Artem Alikhanian (1908–1978), was also a physicist. They had two sisters: Araksia (b. 1906) and Ruzanna (b. 1913). From 1912 to 1913, the family lived in Alexandropol, where Abraham attended a commercial college. They then moved to Tiflis, where they lived until 1918. The family then moved back to Alexandropol, where they lived until the 1920 Turkish–Armenian War. They then moved back to Tiflis, where Abraham graduated from a commercial college the next year. He then enrolled in the Polytechnic Institute of Tiflis but, for the most part, did not study in order to financially support himself and his family. He worked as a cashier and telephone operator.
Early career in Leningrad (1927–41) In 1923, Abraham moved to Leningrad and enrolled in the chemistry department of the Polytechnic Institute. He Russified his name to Abram Isaakovich Alikhanov. The next year, he transferred to the department of physics and mechanics, founded by Abram Ioffe. Besides Ioffe, other prominent scientists taught there, including Nikolay Semyonov and Yakov Frenkel. From 1925 to 1927, Alikhanov worked at the Mechnikov Hospital as a radiographer. He graduated in 1929.
X-rays (1927–33) In 1927 Alikhanov began working part-time at the Physical-Technical Institute in Leningrad as a researcher focusing on X-rays, X-ray diffraction, and solid-state physics. In 1929 he published his first paper on the use of X-ray analysis in investigating the crystal structure of the copper-aluminium alloy. In 1929, after graduating from the Polytechnic Institute, he was employed by the Physical-Technical Institute full-time. He began a long-time collaboration with his younger brother, Artem, and Lev Artsimovich in 1930. Under the supervision of Pyotr Ivanovich Lukirskii, head of the X-ray laboratory, Alikhanov and Artsimovich studied X-ray optics from 1930 to 1933. Results included a "study of total internal reflection of X-rays from thin layers of various substances." He showed that aluminium does not undergo allotropic transformation when X-rayed at 550–600 °C. He also did a "study of the total internal reflection of X rays from thin layers and the estimation of the depth of their penetration into the medium. Alikhanov also proved that the laws of classical optics can be applied to the reflection of hard X rays." Alikhanov summarized the results in a 1933 monograph titled X-Ray Optics (Оптика рентгеновских лучей).
Nuclear physics (1933–41)
Alikhanov switched to nuclear physics in 1933, following the discovery of the neutron and the positron in 1932. Abram Ioffe appointed Alikhanov head of the positron laboratory at the Department of Solid-State Physics at the Physical-Technical Institute. His group studied pair production and gamma rays and made observations of positrons using Geiger counters. According to Viktor Frenkel, their work became a "starting point for the application of radio engineering to experimental nuclear physics in the Soviet Union."
Abov wrote that in 1933–34 Alikhanov and his colleagues were the "first to study in detail the spectrum of positrons from external pair conversion over the entire energy range. Among other things, they showed that, in accord with relevant theoretical results, the maximum of the spectrum occurs in the vicinity of the positron energy equal to half the endpoint energy." He added, "those investigations made it possible to reveal gamma lines that had previously been unknown, whereby it was possible to reconstruct the diagrams of decays of excited nuclei."
They went on to study beta decay using not the usual Wilson cloud chamber, but a spectrometer developed by Alikhanov and Mikhail Kozodayev. It was a "radically improved" version of the "classical magnetic spectrometer with transverse field, fitting it with a system of coincidence-coupled gas-discharge counters. The use of this registration system was an important methodological novelty. It opened the way to development of Soviet nuclear electronics, which has been advanced in many of its aspects by Alikhanov's students. The new magnetic spectrometer was capable of registering the comparatively infrequent processes of positron production and could be used to investigate their energy spectra, the dependence of positron yield on γ-quantum energy and on the atomic number of the element, etc."
In 1934 Alikhanov and Igor Kurchatov built a "baby cyclotron", which became the first "cyclotron" operating outside of Berkeley, California where Ernest Lawrence had invented it years earlier. It did not operate for long, though some experiments were conducted. The first proper cyclotron in the Soviet Union was built at the Radium Institute in Leningrad by 1936.
Alikhanov "discovered that positrons were present even in the absence of a converter made from a heavy element, and this led him to the discovery of a new phenomenon—production of an electron-positron pair as a result of internal conversion of the energy of the excited nucleus." This was later used in nuclear spectroscopy. Alikhanov's group also studied scattering of fast electrons in matter and beta spectra of radioactive substances. In 1938 Alikhanov discovered a new method of determining the rest mass of the neutrino using decay of the nuclei of 7Be.
He was awarded a PhD in Physical and Mathematical Sciences in 1935. He lectured at the St. Petersburg State Transport University in 1939–41 and chaired its Department of Physics.
Cosmic rays and Armenia (1941–43) Alikhanov planned to study cosmic rays, the only source of high-energy particles known at that time, in the Pamir Mountains in the summer of 1941, however, due to the approaching Nazi forces, Alikhanov and the Institute for Physical Problems were evacuated to Kazan in October 1941. In April 1942 he moved to Yerevan, Soviet Armenia with the intention to study cosmic rays at Mount Aragats. The expedition to Aragats resulted in the discovery of the "presence of an intense group of protons with comparatively small energies in the soft cosmic-radiation component" and "presence of a stream of fast protons in cosmic radiation."
Alikhanov and his group, including his brother Artem Alikhanian, also erroneously concluded in the existence of cosmic radiation particles, called by them varitrons, which supposedly possessed a broad spectrum of masses. Alikhanov-Alikhanian brothers were widely criticized for the claim. Turkevich noted in 1956 that "this claim was questioned in the West and attacked by a group of Soviet physicists, with a subsequent bitter polemic in the Soviet physics journals. The controversy has never been settled officially, and Soviet cosmic ray research has suffered a lack of prestige." Luis Walter Alvarez noted that the brothers received the Lenin Prize for their unverifiable discoveries and "for them to have retracted their claims would have been embarrassing to their government."
Alikhanov and his brother Artem established the Yerevan Physics Institute (YerPhI) in 1943 as a branch of Yerevan State University.
Career in Moscow (1943–68) After returning to Russia from Armenia, Alikhanov worked at the Institute for Physical Problems in Moscow from 1944 to 1946.
Between 1947 and 1951 Alikhanov headed the Department of Structure of Matter at the Faculty of Physics and Technology of Moscow State University. He helped organize the Nuclear Physics Division of the Soviet Academy of Sciences.
Among Alikhanov's students were Boris S. Dzhelepov, Venedikt P. Dzhelepov, Mikhail S. Kozodaev, Sergey Ya. Nikitin, Pyotr E. Spivak.
Atomic bomb project Alikhanov was involved in the Soviet atomic bomb project. After the Soviet authorities learned of the German, British and American programs of nuclear weapons in mid-1942, works began on the Soviet project led by Igor Kurchatov. At Laboratory no. 2, Alikhanov was assigned to develop a nuclear pile with heavy water. Lev Artsimovich, Isaak Kikoin, and Anatoly Alexandrov worked on electromagnetic isotope separation, gaseous diffusion process and thermal diffusion process, respectively. While Alikhanov led the research on the construction of a heavy-water reactor. In August 1945 the Special Committee under the Council of Ministers (Council of People's Commissars) was formed to oversee works on uranium, headed by Lavrentiy Beria. The Scientific-Technical Council was headed by Boris Vannikov and included Alikhanov (initially as it scientific secretary), Igor Kurchatov, Pyotr Kapitsa, Abram Ioffe and others.
ITEP
On December 1, 1945, Laboratory no. 3 of the Soviet Academy of Sciences was established in Moscow with Alikhanov as its head. The laboratory was renamed to Heat-Engineering Laboratory (Теплотехническая лаборатория) in 1949 and received its modern name, the Institute for Theoretical and Experimental Physics (ITEP), in 1958. Alikhanov lead the institute for 23 years, until he retired in 1968. Lev Landau and his student Isaak Pomeranchuk headed the theory division of the institute in 1945–46 and 1946–66, respectively.
At ITEP, Alikhanov led research on and advanced scintillation techniques, bubble chambers, and spark chambers.
Nuclear reactor The laboratory/institute initially focused on what Alikhanov had already begun working on: construction of a nuclear reactor based on heavy water. With a small staff, Alikhanov led the design of the first reactor by 1947. It was built in 1948 and successfully put into operation on April 25, 1949. Alikhanov was personally heavily involved in the project. He solved all the "physical and technical problems that arose in construction of the reactor," and tackled the "dirtiest jobs without hesitation; thus the reactor was for the most part his creature." It was the first heavy-water research reactor in the USSR. A number of studies and discoveries were done based on it. It was shut down in 1987.
The reactor was not invented for nuclear power generation, but instead for experiments that would advance the design and construction of other reactors. In 1959 Alikhanov led the design of 10 MW experimental research heavy-water reactors, which were built in China and Yugoslavia under his supervision.