LUKIRSKII, PETR IVANOVICH

(b. Orenburg, Russia, 13 December 1894; d. Leningrad, U.S.S.R., 16 November 1954)

Physics.

Lukirskii’s father, Ivan Egorovich Lukirskii, was a land surveyor; his mother, Evodkia Stepanovna, was a housewife. In 1903 the family moved to Novgorod, where Lukirskii graduated from the gymnasium in 1912 (with a gold medal) and in the same year entered the Faculty of Mathematics and Physics of Petersburg University. In 1915 he graduated from the university but remained there to prepare for the professorship. Approximately at the same time, along with his university activities. Lukirskii joined the seminar on modern physics headed by A. F. Ioffe, which met at the Polytechnic Institute. (From this seminar came such outstanding physicists as I. G. Dorfman, P. L. Kapitsa. N. N. Semenov, and Y. I. Frenkel.) In 1918 Lukirskii became one of the first fellows of the Physical-Technical Institute (PTI), founded by loffe, where he concentrated on problems of electron physics. He is rightfully considered to have initiated this field in the U.S.S.R. In one of his first experimental works (with Semenov, 1923), he investigated the scattering of electrons from the surface of liquid mercury. At that time there were no satisfactory metallic monocrystals; mercury, with its ideally smooth surface (from which it was easy to remove the layers of absorbed substances), was a happy choice for the determination of the work function of secondary electrons and their angular and energy distributions.

Another of Lukirskii’s fields was X-ray physics (he was the head of that department at PTI). Being interested in soft X-rays (10–150Å), which are difficult to study with optical and crystal lattices, he suggested using maximum values of the energy of photoelectrons knocked from the surface of a sphere to determine, via Einstein’s relation, the wavelength of the incident X-rays. (The sphere served as one electrode of a spherical condenser). The spherical condenser method resulted in substantially more accurate measurements and became standard for Lukirskii’s investigations. With its aid he demonstrated the effect of polarization of X rays in Compton scattering and investigated the normal photoeffect from the surface of pure metals; he also determined the Planck constant with great accuracy.

Lukirskii next turned to further investigations of the photoeffect. Using the method of mote in Millikan’s condenser (employed by Millikan in mea suring the electron charge), he determined the value of the photoeffect threshold for a number of crystals. He also studied the selective photoeffect and the influence of absorption of impurities on the metal’s surface on the value of the electron work function. These investigations had considerable applied importance. Lukirskii was scientific head and consultant of research laboratories of the “Svetlana” plant, the largest producer of vacuum tubes in the Soviet Union in the early 1930’s.

In the mid 1930’s Lukirskii and his collaborators developed the first antimony-cesium photoelement. Its cathode demonstrated the greatest sensitivity then recorded in the violet and ultraviolet spectral regions, and the spectral characteristics were stable over time and not very sensitive to variations in the technology of cathode production. Lukirskii’s antimony-cesium cathode has played a significant role in the Soviet Union not only in engineering, electronics, automation, and astrophysics, but also in sound cinematography. Lukurskii initiated research work on autoemission electronics in the Soviet Union (1944–1950); the points of the emiters he investigated were also covered by antimony-cesium layers.

In 1944 Lukirskii carried out the classic experiment related to the problem of the equilibrium form of crystals. Heating a sphere of rocksalt, he showed that the equilibrium figure is a polyhedron with curved ribs. (A rough demonstration of this phenomenon was that the sphere, which had been freely rolling along the smooth surface, started “jumping” on it after being heated.) These works stimulated theoretical investigations of equilibrium forms of crystals (L. D. Landau, Frenkel) and the mechanism of natural roughness of crystals.

Lukirskii also studied problems of nuclear physics. From 1943 until the end of his life he headed the physics department at the Radium Institute of the Academy of Sciences of the U.S.S.R. Even earlier, in 1936, he had already begun experiments on elastic scattering of neutrons. A number of his researches involved nuclear reactions in thick-layered emulsions. For example, he investigated the reaction Be⁹ + π → Li⁷ + 2n, in which both neutrons go off in the same direction (bineutron). In collaboration with Zhdanov he investigated nuclear reactions caused by a heavy meson (the negative K-meson).

Lukirskii devoted great attention to teaching, and was a good lecturer. From 1919 to 1938 he taught at Leningrad University; for a number of years, he occupied a chair at the Leningrad Institute of Cinematographic Engineers; and from 1945 until his death, he served as professor and head of the department of physical electronics at the Leningrad Polytechnic Institute. Lukirskii was elected a corresponding member of the Academy of Sciences of the U.S.S.R. in 1933 and a full member in 1946. He was an excellent sportsman, especially absorbed by yachting and tennis. He was married to Elizaveta Nikolaevna, with whom he had one daughter and two sons.

BIBLIOGRAPHY

I. Original Works. Monographs include Osnovi elektronnoi teorii (Fundamentals of electron theory; 2nd ed., Moscow and Leiningard, 1929); O fotoeffekte (On the photoeffect; Leningrad and Moscow, 1933); Neitron (Neutron; Leningrad and Moscow, 1935); Stronie veshchestva (The structure of matter; Leningrad, 1938), pts. 1–3. Papers include “Rasseyanie elektronov zhidkoi rtutiyu” (Electron scattering on liquid mercury surface), in Zhurnal Russkogo fiziko-khimicheskogo obschestva, chast fizicheskaia, 55 , nos. 1–3 (1923), 107–119; “Photoeffect an Kristallen,” in Zeitschrift fä Physik, 37 , nos. 4–5 (1926), 308–318; “Issledovanie skorostei fotoelektronov” (The study of photoelectron velocities), in Zhurnal Russkogo fiziko-khimicheskogo obshchestva, chast fiziches kaia, 58 , no. 2 (1926), 319–328, written with S. S. Prilezhaev; “Über den normalen Photoeffekt,” in Zeitschrift für Physik, 49 , nos. 3–4 (1928), “The Compton Effect and Polarisation,” in Nature, 122 (1928), 275–276; “Versuche über die Eigenshaften der Atomschicten” in Zeitschrift für Physik, 71 , nos. 5–6 (1931), 306–324; “Abhängigkeit der lichtelektrischen Emission des Kaliums von der Anrodnung von atomaren Wassertoff-und Kaliumschichten auf ihrer Oberflache,” ibid., nos. 3–4 (1932), 249–252; “Slow Neutrons,” in Nature, 136, (1935) 681–682, written with T. Tsareva; “On the complex Photocathode Mechanism,” in Techn. Phys. URSS, 3, no. 8 (1936), 685–699; “Experiments with Rock-Salt Crystals,” in Comptes-rendus del’Académie des sciences de l’ URSS, 46, no. 7 (1945), 274–276; “The Negative Meson and its Mass,” ibid., 54, no.3 (1946), 219–222; “Opoti po izucheniiu avtoelektronnoi emissii pri zazlichnikh temperaturakh” (Experiments on autoelectronic [field] emission at various temperatures), in Sbornik posvyashchennii 70-letiiu aka demika A. F. Ioffe (Moscow, 1950), 109–112, written with T. V. Tsareva; “Iadernoe rasshcheplenie tyazhelim mesonom” (Nuclear splitting by heavy mesons), in Doklady Akademii nauk SSSR, 94, no. 5 (1954), 843–844, written with Iu. G. Degitariev and A. P. Zhdanov.

II. Secondary Literature. Obituaries are in Uspekhi fizicheskikh nauk, 55, no. 3 (1955), 289–295; Vestnik LGU, ser. mat. i fiz., no. 2 (1955), 203–204; and Zhurnal tekh nicheskoi fiziki, 25, no. 3 (1955), 367–367. See also Piotr Ivanovich Lukirskii (1894–1954) (Moscow, 1959).

V. J. Frenkel