Abram A. Slutskin

Abram A. Slutskin (1881–1950) was a Russian scientist and professor who had a major role in shaping radio science in the Soviet Union. He was a pioneer in cavity magnetron development and the application of these devices in radio-location (radar) systems.

Slutskin, a native of Ukraine, entered the Kharkov University (KU) in 1910. He received the Kandidat Nauk (Candidate of Science – approximately equivalent to the Ph.D. degree) from the Physics-Mathematics Department in 1916, and remained there as a docent and researcher during the turbulent times of the Russian Revolution. In 1921, prominent physicist Dmitry Rozhansky started a research department of physics at KU. Slutskin joined this activity as soon as it was formed.

Rozhansky had a strong interest in high-frequency electromagnetic oscillations, and influenced Slutskin to begin research in this area. The earlier work on magnetrons by Albert Hull (American), August Žáček (Czech), and Erich Habann (German) was studied and improved, resulting in devices generating oscillations with wavelengths between 300 to 40 cm., (It is noted that Shteinberg was the supervisor of the research unit, and, by custom, his name was added as such.) During 1928-1930, Slutskin studied in Germany under Heinrich Barkhausen at the Dresden Technische Hochschule. While there, he published another important paper on magnetrons in Annalen der Physik, a highly respected and widely read German journal.

In 1928-1929, the Ukrainian Physico-Technical Institute (UPTI) was established as a Soviet research organization in Kharkov. (The Institute was later renamed Kharkiv Institute of Physics and Technology, but the original name is used herein.) The primary staff, including Ivan V. Obreimov, the director, was transferred from the Leningrad Physico-Technical Institute (LPTI), but the UPTI shared many senior personnel with KU. Upon his return from Germany, Slutskin was awarded the D.Sc. degree from KU, elevating him to the rank of professor. He was also added to the UPTI staff, heading a newly formed Laboratory of Electromagnetic Oscillations (LEMO). Here he continued with the development of magnetrons and other ultra-high-frequency (UHF) devices. At KU, his students included Aleksandr S. Usikov, Semion Y. Braude, and Ivan D. Truten, all of whom would later make major contributions in this field at the LIPT.

Under Slutskin’s leadership, research at the LEMO resulted in water-cooled magnetrons generating continuous power up to 17 kW at 80 cm, and a magnetron tunable over a 30 percent wavelength variation (only reported much later). Research was also performed on frequency control and pulsed modulation. Work on magnetrons and their applications was also underway at the LIPT, and the LEMO supplied their products to researchers in Leningrad. The development of the L-Band (15–30 cm, 2–1 GHz) magnetron gained the attention of the Technical Department of the Red Army. The UPTI was tasked to investigate magnetrons for use in radio-location (radar) units. From this, an un-cooled magnetron was developed that generated pulsed power up to 60 kW at 60 to 65 cm.

In March 1937, the LEMO started an internally funded project to develop a pulsed, electromagnetic, gun-aiming system. Slutskin was responsible for the overall project under the code name Zenit, the name of a popular football team at that time. Development of the pulsed, L-band transmitter was under Usikov, and Braude designed a superheterodyne receiver using a low-power magnetron as the local oscillator. This system, with transmitting and receiving antennas separated by about 50 m, was first tested in October 1938, detecting an aircraft at 3 km in its first version.

The receiver of the initial Zenit system was not sufficiently sensitive, and was redesigned by Truten using a 955 acorn triode from RCA. In September 1940, Slutskin demonstrated the revised Zenit to the Red Army and Red Navy, detecting aircraft at ranges up to 25 km. This was the first full three-coordinate, radio-location system in the Soviet Union. However, the time required to measure the coordinates (distance, azimuth, and elevation) was too long for gun-laying in anti-aircraft batteries. Although not accepted by the military, the Zenit did show the way for further developments.

While the Zenit was being developed, there was major discord within the UPTI. The radio-location work at the LEMO was conducted in great secrecy, and other units of the UPTI objected to the lack of “freedom of scientific knowledge.” It was also learned that LEMP scientists were paid substantially more than other UPTI professionals. This resulted in a push to have LEMP become a totally separate organization. At this same time, Joseph Stalin’s Great Purge swept the nation, and the UPTI was a target. Many persons were arrested under charges of sabotage and two were executed by a firing squad. Slutskin and his LEMO staff, however, remained safe and turned to converting the Zenit to a new, improved system.

Germany started the invasion of the USSR in June 1941, and Kharkov was a primary target. In a short while, all of the critical operations in Kharkov were ordered to evacuate into the Far East. For this, the UPTI was split, most going to Alma-Ata in Kazakhstan, and the LEMO to Bukhar in Uzbekistan, separated by 1,500 km; thus the war accomplished what the scientists had earlier failed to do. The evacuation started in October 1941, but it was well into 1942 before facilities in Bukhara were in operation.

With Slutskin remaining the director, the new radio-location project was placed under Truten. Code-named Rubin, this system used an improved transmitter and receiver from Zenit, but had a single antenna, made possible by a device (a duplexer) personally developed by Truten. The times for determining coordinates were greatly reduced by displaying measurements on a cathode-ray tube. By August 1943, a prototype Rubin system was completed and transported to Moscow, where it was demonstrated in an anti-aircraft battery. While the Rubin was being developed, however, the USSR received a GL Mk II radar from the British. This was a well-tested, gun-laying system and was immediately reverse-engineered and placed into production, thus eliminating the need for the Rubin.

As the war closed in the summer of 1945, both the UPTI and the LEMO returned to Kharkov (changed in spelling to Kharkiv), but remained fully separate organizations. Slutskin, then in his mid-60s, continued to head the LEMO as well as serving as a professor at Kharkiv State University. Earlier, in 1939, Slutskin had been elected as a Corresponding Member of the Academy of Sciences of Ukraine, and in 1948, his status was upgraded to Academician. Before he died in 1950, Slutskin gradually turned the LEMO leadership over to Truten and Usikov. In 1955, the LEMO became the Institute of Radio-Physics and Electronics (IRE), initially headed by Usikov.

According to standard practice, Abram Slutskin cannot be named "Russian scientist" because he lived and worked all his life in Ukraine. For instance, his most famous former student Semion Braude is correctly mentioned in Wikipedia as "Ukrainian scientist." He can be called, however, a Soviet scientist although he started his research career well before the communist revolution [1a,2a]. He was an ethnic Ukrainian Jew (similarly to S. Braude) by his origin. Through his career, Slutskin had much stronger ties with the Academy of Sciences of Ukraine than with any organization or agency in Russia. Until his death he remained strongly negative to the involvement of UPTI under the umbrella of the Moscow-based 1-st Chief Directorate (nicknamed "Nuclear Politburo") and kept his LEMO out of this structure [1a].

The magnetrons developed by Slutskin between 1925 and 1941 were not the "cavity magnetrons" that became famous during the World War II, they were the "split-anode magnetrons" [2a]. This device had no internal high-quality cavities that stabilized the frequency of the generated electromagnetic oscillations. As a result, the split-anode magnetrons were extremely unstable sources and their use in the design of pulsed radar was not successful. The true cavity magnetron was invented by Randall and Boot in 1939-1940; it had 6 and later 8 side cavities at 10-cm wavelength and 10 kW output power. A similar device of Alekseev and Malyarov dated 1936 (their Soviet paper published in 1940 was translated in the USA in 1944 where Malyarov was erroneously typed as "Malairov"); however it had only 4 side cavities and therefore the output power was only 300 W at 9 cm [3a]. This was in fact the design of M. Bonch-Bruyevich who was under investigation for (false) sabotage at that moment and whose name was apparently not allowed for mentioning.

UPTI and LEMO did not come back to Kharkiv in 1945 as separate entities; instead, LEMO had remained a department (later, a sector) inside UPTI till the final separation in 1955 [1a]. A. Slutskin had been remaining a staunch opponent of the separation of LEMO (that was pushed by K. Sinelnikov, the post-war director of UPTI with support of the 1-st Chief Directorate) until his death. He died unexpectedly in 1950 of the heart attack when waiting for a flight back from Moscow. He was very strong character and it is a mistake to believe that he was thinking about delegating his leadership in LEMO to Truten or Usikov. His most talented and high-positioned student at that moment (and later on) was S. Braude - the only one who had a higher doctorate (D.Sc., since 1943). In his last interview around 2000, Braude recalled how, in the late 1940s, Slutskin charged him with doing research into the microwave propagation but removed him from the magnetron research telling that magnetrons were to be pursued by Slutskin himself.

[1a] A.A. Kostenko, A.I. Nosich, Y.N. Ranyuk, “Prehistory of the IRE NASU”, Science and Science of Science, Kiev, no. 4, pp. 102–135, 2005 (in Russian).

[2a] A.I. Nosich, A.A. Kostenko, "In the labor people's name: development of 60-kW magnetrons in the artificial famine plagued Ukraine in the early 1930s," Proc. Int. Conf. Origins and Evolution of the Cavity Magnetron (CAVMAG-2010), Bournemouth, 2010, pp. 82–88.

[3a] M.M. Lobanov, Beginning of the Soviet Radar, Sovetskoe Radio Publ., Moscow, 1975 (in Russian).

• Erickson, John; “Radio-location and the air defense problem: The design and development of Soviet Radar 1934-40,” Social Studies of Science, vol. 2, pp. 241–268, 1972
• Tvrnov, O. F. and B. G. Yemets; “Fifty years of Kharkov University’s Department of Radio Physics,” Proc. of the IEEE International Crimean Conference, pp. 824–826, Sept. 2003
• Watson, Raymond C., Jr.; Radar Origins Worldwide: History of its Evolution in 13 Nations Through World War II, Trafford Publishing, 2009