Konstantin Petrzhak

Konstantin Antonovich Petrzhak (alternatively Pietrzak;[1] Russian: Константи́н Анто́нович Пе́тржак, IPA: [kənstɐnʲˈtʲin ɐnˈtonəvʲɪtɕ ˈpʲedʐək], Polish: [ˈpjɛt.ʂak]; 4 September 1907– 10 October 1998) was a Russian nuclear physicist of Polish origin, and a professor of physics at the Saint Petersburg State University.

Konstantin Petrzhak
Константин Антонович Петржак
Konstantin Petrzhak.jpg
Konstantin Petrzhak (1907–1998)
Konstantin Antonovich Petzhak

(1907-09-04)September 4, 1907
Łuków, Poland, Russian Empire
(Present day in Łuków in Poland
Or in Dombrovo, Kaliningrad in Russia)
DiedOctober 10, 1998(1998-10-10) (aged 91)
Citizenship Russia
Alma materLeningrad State University
Known forDiscovery of spontaneous fission
Soviet atomic bomb project
AwardsSoviet Union State Prize (1950)
Scientific career
FieldsNuclear Physics
InstitutionsKhlopin Radium Institute
Academic advisorsIgor Kurchatov

Receiving credit with Georgy Flyorov, a physicist, for the discovery of spontaneous fission of uranium in 1940, he also greatly aided in Russia's atomic bomb project.[2]


Early and personal lifeEdit

Konstantin Petrzhak was born in Łuków, Poland in Russian Empire, on 4 September 1907.[3][4] Other Russian documented sources noted his birthplace in Dombrovo in Kaliningrad with same birth date.[4] There is very little information known about his early life and started working at the age of 12 (in 1919) as a painter at a glass-making factory in Malaya Vishera in Russia to provide income to his poor family.[4] In 1928, Petrzhak was sent to attend the trade school, Rabfak, that was affiliated with the Leningrad State University (now St. Petersburg Univ.), where he studied painting which remained his lifelong passion.[5] Later, he used his talent in painting when he covered the plates of ionization chamber with uranium which later led to discovery of spontaneous fission.[5] He also learned to play the music and was an amateur violinist and guitar player.[5]

Peterzhak went to the Leningrad State University worked with the research group at the university in 1931.[6] In November 1936, Pertzhak eventually earned his diploma certified under Igor Kurchatov[7] from the Leningrad State University.[6]

Konstantin Petrzhak married Galina Ivanovna Mitrofanova (b. 1918), also a radiochemist.[5]

In 1934, Petrzhak found the work at the Khlopin Radium Institute located in the State University in Saint Petersburg (First Radium Institute), which was directed by Igor Kurchatov, a nuclear physicist.[7]

Petrzhak remained associated with the Khlopin Radium Institute for the remainder of his life, and worked under the direction of Vitaly Khlopin and Igor Kurchatov where he eventually defended his thesis at the Ioffe Institute to obtain the Candidate of Sciences, titled: "Study of thorium and samarium radioactivity."[8][9][10][11]

Soviet atomic bomb project and academiaEdit

In 1939, Kurchatov was assigned research under Georgy Flyorov and Petzhak to conduct investigation on uranium fission induced by neutrons of different energy levels, following Yakov Frenkel's theory of fission.: 54[12][13] Earlier, Flyorov and his assistant Tatiana Nikitinskaya had already made an ionization chamber to detect heavy particles, and were directed to increase the sensitivity of the ionization chamber.[14][14] The team created a multilayer ionization chamber to detect decay products originating from the fission of uranium.[15][16]

The ionization chamber utilized electrodes with a total surface area of about 1000 cm2.[17] The chamber's 15 plates[18] were covered with uranium oxide with approximate surface density of 10–20 mg/cm2.[15] The detector compared particle activity to a background level control.[19] When the source of neutrons was taken away, the detector still found particles. The team made three ionization chambers to prove that the effect was not an error, including a more sensitive chamber with a surface area of 6000 cm2. Despite the instrument's high sensitivity, cosmic rays were still a possible source of particle activity. The team moved to an underground lab in the Dinamo station of Moscow Metro (about 50 m below the earth surface)[20] in an attempt to rule out the effects of cosmic rays. In May 1940, they were confident that they had discovered spontaneous fission.[21] The certificate of discovery stated, "the new type of radioactivity with mother nucleus decays into two nuclei, that have kinetic energy of about 160 MeV".[22][23] Later, the discovery of spontaneous fission was confirmed by Otto Robert Frisch.[24]

In 1940, Petrzhak was recommended for the top team in the Soviet atomic bomb project.[25] He is rumored to have participated in the said project.

When the Soviet Union entered World War II, Petrzhak was eligible to serve in the Red Army. Winning the Stalin Prize would exempt him from front line service. In the early 1940s, the Soviet Academy of Sciences nominated him for the award, which he did not receive.[26] Sources disagree on whether Petrzhak volunteered,[11] or was drafted[27] into the army.

Petrzhak served in the military intelligence company of a CIWS regiment first as a junior lieutenant,[28] and later as a senior lieutenant.[29][30] On 28 June 1941, he participated in the battle of Karelian Isthmus. Later, he fought in Volkhov Front.[27] In March 1942 he was ordered to leave the army[8] and join evacuated Radium Institute scientists in Kazan.

In 1943, Petrzhak studied neutron induced fission of uranium under the supervision of professor Piotr Lukirski. In 1944, Petrzhak proposed a method to determine the number of neutrons present during a nuclear reaction, based on the number of protons. He also participated in the development of technology to extract plutonium from irradiated uranium blocks. Jointly with M. Yakunin, Petrzhak developed methods for the radiochemical determination of plutonium, and found the mean free path of Pu-239 alpha particles. Petrzhak founded a laboratory of neutron physics and nuclear fission at the Khlopin Radium Institute in 1947. He was the head of this laboratory until 1986,[4] when he became a part-time contractor.

In 1949, Petrzhak was appointed a member of the Uranium Commission of the Soviet Academy of Sciences.[31] He was one of the founders of the Engineering faculty of the Saint Petersburg State Institute of Technology.[32] Petrzhak founded the Saint Petersburg State Institute of Technology department of nuclear physics in 1949,[4] and remained its chair for 22 years.[33] In 1958, he supervised Vladimir Georgievich Korsakov's diploma work.[34]

Konstantin Petrzhak created an express method to detect plutonium and associated radioisotopes in samples of irradiated uranium.[4] From 1963 to 1976, he published a series of articles on the measurement of photofission.[35][36] From 1973 through 1984, he took part in measuring induced fission cross-sections of U-238, U-235 and Pu-239 when irradiated by monoenergy neutrons[37][38] In 1978, Konstantin Petrzhak co-authored a paper (with Yuri Oganessian and others) about synthesis of hassium performed in Joint Institute for Nuclear Research.[39]

Petrzhak was doktor nauk (since 1948) and a professor. He was never elected an academician or the corresponding member of any academy, but Petrzhak was a member of Nuclear Physics Department of Russian Academy of Sciences.[40] According to SCOPUS, Konstantin Petrzhak has 59 publications with Hirsch index 6.[41] Konstantin Petrzhak published articles on fission products from nuclear reactors[42] until his death in 1998. He died on October 10, 1998 and was buried in Saint Petersburg.

Personal lifeEdit

Konstantin Petrzhak studied painting. He created paintings throughout his life. He used his skills in painting when he covered the plates of ionization chamber with uranium which later led to discovery of spontaneous fission. He was also an amateur violin and guitar player.[5] Konstantin Petrzhak married Galina Ivanovna Mitrofanova (b. 1918), also a radiochemist.


Selected worksEdit

  • Flerov GN, Petrzhak KA (1 July 1940). "Spontaneous fission of uranium". Phys. Rev. 58 (1): 89. Bibcode:1940PhRv...58...89F. doi:10.1103/PhysRev.58.89.2.
  • Adamov VM, Drapchinsky LV, Kovalenko SS, Petrzhak KA, Pleskachevsky LA, Tyutyugin II (1974). "Polar light particle emission in spontaneous fission of 252Cf". Physics Letters B. 48 (4): 311–314. Bibcode:1974PhLB...48..311A. doi:10.1016/0370-2693(74)90597-8.
  • Dushin, V.N.; Fomichev, A.V.; Kovalenko, S.S.; Petrzhak, K.A.; Shpakov, V.I.; Arlt, R.; Josch, M.; Muziol, G.; Ortlepp, H.G.; Wagner W. (1982). "Statistical analysis of the experimental data of fission cross section measurements on 233, 235, 238U, 237Np, 239, 242Pu at neutron energies of 2.5, 8.4 and 14.5 MeV". Proc. of XIIth International symp. on nuclear physics. Gaussig, 1982, ZfK-491. Dresden. p. 138.
  • Петржак, К. А.; Флеров, Г. Н. (1940). Спонтанное деление урана [Spontaneous fission of uranium]. ЖЭТФ (in Russian). 10: 10–13.
  • Петржак, К. А.; Флеров, Г. Н. (1941). Спонтанное деление урана [Spontaneous fission of uranium]. Успехи Физических Наук (in Russian). 25 (2): 241–249. doi:10.3367/UFNr.0025.194102i.0241.


  1. ^ Константин Антонович Петржак (Konstantin Pietrzak). Ядерная физика в Интернете (in Russian). Retrieved November 10, 2014.
  2. ^ Petrzhak KA, Flerov GN (1940). "Spontaneous fission of uranium". Proc USSR Acad Sci. 28 (6): 500.
  3. ^ "Konstantin Antonovich Petrzhak". www.npd.ac. Moskva: RuHEP-NP. 10 October 1998. Retrieved 20 July 2018.
  4. ^ a b c d e f "Konstantin Petrzhak" Константин Петржак. Russian Engineers (in Russian). 2010.
  5. ^ a b c d e Холодная, Варвара (5 June 2009). Не пропусти! [Do not miss]. Вечерний Петербург (in Russian). 102 (23946). Retrieved December 22, 2014.
  6. ^ a b Драпчинский, Л.В. К 100-летию со дня рождения К.А. Петржака [To 100-year anniversary of K. A. Petrzhak]. Семейные истории. Retrieved October 31, 2014.
  7. ^ a b Асташенков 1968, p. 92.
  8. ^ a b Konstantin Petrzhak obituary
  9. ^ Гринберг, А.П.; Френкель, В.Я. (1984). Igor Vasilyevich Kurchatov in Ioffe Institute (1925-1943) Игорь Васильевич Курчатов в Физико-техническом институте (1925-1943 гг.). Ленинград: Наука. p. 181. Retrieved November 12, 2014.
  10. ^ Иоффе, А. Ф. (1985). "Открытие молодых советских ученых" (PDF). О физике и физиках [About physics and physicists]. Наука. Мировоззрение. Жизнь (2 ed.). Ленинград.: Наука. Ленинградское отделение. Retrieved October 31, 2014.
  11. ^ a b Гапонов Ю. В. (2003). Игорь Васильевич Курчатов (1903-1960). Жизненный путь (К столетию со дня рождения) [Igor Vasilievich Kurchatov (1903-1960). Life way (to 100th anniversary)]. Физика элементарных частиц и атомного ядра. 34 (3): 530.
  12. ^ Holloway, David (1994). "§(Reacting to Fission)" (google books). Stalin and the Bomb: The Soviet Union and Atomic Energy, 1939-1956. Yale University Press. p. 450. ISBN 0300066643. Retrieved 24 July 2018.
  13. ^ Отто Ган [Otto Hahn] (in Russian). Archived from the original on 2015-09-25.
  14. ^ a b Асташенков 1968, p. 93.
  15. ^ a b Мухин 1974, p. 477.
  16. ^ Oganessian, Yuri (2003). Г. Н. Флёров. Молодые годы [G. Flyorov. Early years] (DOC) (in Russian).
  17. ^ Кузнецова, Р.В. Многослойная ионизационная камера [Multilayer ionization chamber]. Приборы и инструменты России (in Russian). p. 15.
  18. ^ Мухин 1974, p. 478.
  19. ^ Flerov GN, Petrzhak KA (1961). Спонтанное деление ядер [Spontaneous fission of nuclei] (PDF). Physics-Uspekhi (in Russian). LXXIII (4): 657.
  20. ^ Асташенков 1968, p. 96.
  21. ^ Paul Kuroda (2012). The Origin of the Chemical Elements and the Oklo Phenomenon. Springer Science & Business Media. p. 32. ISBN 978-3642686672.
  22. ^ Открытие спонтанного деления урана [Discovery of spontaneous fission in uranium] (in Russian).
  23. ^ Флеров, Петржак – Научное открытие №33 Спонтанное деление ядер урана [Flerov, Petrzhak - Scientific discovery №33. Spontaneous fission of uranium]. Научные открытия России (in Russian). Archived from the original on 25 January 2012. Retrieved October 24, 2014.
  24. ^ Гончаров Г. А.; Рябев Л. Д. (2001). О создании первой отечественной атомной бомбы [About the creation of the first national atomic bomb] (PDF). УФН (in Russian). 171 (1): 83.
  25. ^ Создание первой атомной бомбы в СССР [Works on creation of the first atomic bomb in USSR]. BioFile.ru (in Russian).
  26. ^ Губарев, B.C. (2000). XX век. Исповеди: судьба науки и ученых в России. [20th century. Confessions: the destiny of science and scientists of Russia.] (in Russian). М.: МАИК "Наука/Интерпериодика". ISBN 5-7846-0034-6. Retrieved October 31, 2014.
  27. ^ a b Рояль эмоций, Творцы - ч. 170 [Grand piano of emotions. Creators, part 170] (in Russian). Archived from the original on October 31, 2014. Retrieved October 31, 2014.
  28. ^ РФЯЦ-ВНИИЭФ 2000, p. 426.
  29. ^ Зенькович, Николай (2004). Тайны ушедшего века. Власть. Распри. Подоплека [Mysteries of the passing century. Power. Arguments. Causes.] (in Russian). Moscow: ОЛМА Медиа Групп. ISBN 5224046769. Retrieved October 22, 2014.
  30. ^ Крюков, С.Г. Достоин ли А. Сахаров почестей? [Whether A. Sakharov is worth ceremonial?]. Своими именами (in Russian). Retrieved October 31, 2014.
  31. ^ А.С. Дудырев; А.А. Копырин; Б.А. Лавров; А.А. Малыгин; В.Н. Нараев; А.А. Персинен; В.И. Штанько (2008). Наукоемкие технологии в начале XXI века [High technologies at the beginning of 21st century] (PDF). Известия Санкт-Петербургского государственного технологического института (in Russian). 4 (30): 80.
  32. ^ Выпускники и преподаватели [Alumni and Faculty]. Saint Petersburg State Institute of Technology (in Russian).
  33. ^ История кафедры [History of department]. Saint Petersburg State Institute of Technology (in Russian).
  34. ^ Сырков, А.Г.; Малыгин, А.А.; Сычев, М.М. (2014). К 80-летию со дня рождения профессора В.Г. Корсакова [On 80 years of V. G. Korsakov]. Известия Санкт-Петербургского государственного технологического института (in Russian). 24 (50): 104.
  35. ^ Kondrat'ko, M. Ya.; Korinets, V. N.; Petrzhak, K. A. (1976). "Dependence of asymmetry in the photofission of 233U and 239Pu on the maximum bremsstrahlung". Soviet Atomic Energy. 40 (1): 83–84. doi:10.1007/BF01119404. S2CID 101875009.
  36. ^ Петржак, К.А.; Кондратько, М.Я.; Никотин, О.П.; Теплых, В.Ф. (1963). Запаздывающие нейтроны при фотоделении тяжелых ядер [Delayed neutrons during photofission] (in Russian). 15: 157–158. Cite journal requires |journal= (help)
  37. ^ Алхазов, И.Д.; Касаткин, В.П; Косточкин, О.И.; et al. (1974). "Измерение сечения деления 238U нейтронами с энергией 14,6 МэВ" [Measurements of cross-sections of U-238 fission when irradiated with neutrons of energy 14.5 MeV]. Нейтронная физика, Материалы II Всесоюзной конференции по нейтронной физике, Киев, 1973 [Neutron physics, proceedings of II USSR conference on neutron physics, Kiev, 1973] (in Russian). 4. Обнинск. pp. 13–17.
  38. ^ Dushin, V. N.; Fomichev, A. V.; Kovalenko, S. S.; et al. (1983). "Statistical analysis of experimental data on the cross sections of 233, 235, 238U, 237Np, 239,242Pu fission by neutrons of energy 2.6, 8.5, and 14.5 MeV". Soviet Atomic Energy. 55 (4): 656–660. doi:10.1007/BF01124127. S2CID 97167743.
  39. ^ Оганесян, Ю.Ц.; Тер-Акопьян, Г.М.; Плеве, А.А.; et al. Опыты по синтезу 108 элемента в реакции 226Ra + 48Ca [Experiments on synthesis of 108th element in reaction 226Ra + 48Ca] (PDF) (in Russian).
  40. ^ "Members of Nuclear Physics Division of Physical Sciences Department of Russian Academy of Sciences". High Energy and Nuclear Physics in Russia.
  41. ^ K. A. Petrzhak SCOPUS
  42. ^ Teplykh, V. F.; Platygina, E. V.; Petrzhak, K. A. (1998). "Range of products with A=131–136 in the reactor neutron fission of 237Np, 243Am by and thermal neutron fission of 233U, 235U, and 239Pu". Atomic Energy. 84 (4): 292–294. doi:10.1007/BF02415238. S2CID 96393999.
  43. ^ "Russian discovery of atomic secrets". The Canberra Times. 20 (5869). January 29, 1946. p. 1.


  • Асташенков, Петр Тимофеевич (1968). Курчатов [Kurchatov]. М.: Молодая гвардия. p. 24.
  • Мухин, К.Н. (1974). Экспериментальная ядерная физика [Experimental nuclear physics] (in Russian). 1. М.: Атомиздат. p. 477.
  • Горбачев, В. М.; Замятнин, Ю. С.; Лбов, А. А. (1976). Взаимодействие излучений с ядрами тяжелых элементов и деление ядер. Справочник. [Interaction of radiation with nuclei of heavy elements and nuclear fission. Reference] (in Russian). М.: Атомиздат.
  • Рябев, Л. Д., ed. (2000). Атомный проект СССР. Том II. 1945-1954 Книга 2 [Soviet atomic project.] (in Russian). II. Москва-Саров: РФЯЦ-ВНИИЭФ. ISBN 5-85165-402-3.