Abram Alikhanov

Abram Isaakovich Alikhanov (Абрам Исаакович Алиханов, born Alikhanian; 4 March 1904 – 8 December 1970) was a Soviet Armenian experimental physicist who specialized in particle and nuclear physics.

He was one of the Soviet Union's leading physicists.

Alikhanov studied X-rays and cosmic rays before joining the Soviet atomic bomb project.

Alikhanov was born Abraham Alikhanian (Աբրահամ Ալիխանյան) on 4 March 1904 in Elizavetpol (today Ganja, Azerbaijan) to Armenian parents.

They had two sisters: Araksia (b. 1906) and Ruzanna (b. 1913).

His younger brother, Artem Alikhanian (1908–78), was also a noted physicist.

His family lived in Alexandropol (today Gyumri) in 1912–13, where Abram attended a commercial college.

The family then moved to Tiflis (today Tbilisi), where they lived until 1918.

They again moved to live in Alexandropol until the Turkish–Armenian War of 1920.

They returned to Tiflis and Abram graduated from a Tiflis commercial college in 1921.

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.

In 1923 Alikhanov moved to Leningrad and enrolled in the chemistry department of the Polytechnic Institute.

In 1924 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.

His father, Isahak Alikhanian (d. 1925), was a railroad engineer (train driver) in the Transcaucasus Railway, while his mother, Yulia Artemevna (née Sulkhanova), was a housewife.

In 1925–27 he worked at the Mechnikov Hospital as a radiographer.

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.

He graduated in 1929.

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).

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."

In 1934 he and Igor Kurchatov created a "baby cyclotron", the first "cyclotron" operating outside of Berkeley, California.

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.

He was also a pioneer in Soviet accelerator technology.

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 Soviet Armenia and led the Yerevan Physics Institute for many years.