Konstantin Petrzhak: Difference between revisions

Konstantin Petrzhak
Konstantin Petrzhak
Константин Антонович Петржак
	K. A. Petrzhak, photo from the archive of Radium Institute
Born	Konstantin Antonovich Petrzhak; September 4, 1907; Łuków, Siedlce Governorate, Poland in Russian Empire; ((Present-day, Łuków in Poland)
Died	October 10, 1998 (aged 91); Saint Petersburg, Russia
Nationality	Polish
Citizenship	Russia
Alma mater	Leningrad State University
Known for	Discovery of spontaneous fission; Soviet atomic bomb project
Awards	Stalin Prize (1950)
	Scientific career
Fields	Physics
Institutions	Khlopin Radium Institute
Thesis	Study of thorium and samarium radioactivity (1948)

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

Receiving credit with Georgy Flyorov, a physicist, for the fundamental discovery of spontaneous fission of uranium in 1940, Petrzhak's career in physics was then spent mostly in the former Soviet program of nuclear weapons.^[2] Konstantin Petrzhak was among of Soviet pioneers in nuclear physics research.^[3]

Biography

Early and personal life

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, 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 a job 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 program of nuclear weapons and academia

In 1939, Kurchatov was assigned research under Georgy Flyorov and Petrzhak 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 I. 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 Academy of Sciences of the Soviet Union 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] On 20th of March 1942 he was ordered to leave the army^[6] and join evacuated Radium Institute scientists in Kazan.

In 1943, Petrzhak studied neutron induced fission of uranium under the supervision of professor Pyotr Lukirsky. 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] Hundreds of graduates of Engineering faculty studied under his supervision, he was also a scientific supervisor of dozens of Candidates of Science and Doktors of Science.^[4]

Konstantin Petrzhak created an express method to detect plutonium and associated radioisotopes in samples of irradiated uranium.^[4] In 1960s he and his colleagues studied fission with simultaneous emission of protons, tritons and alpha-particles.^[34] In 1960s jointly with the colleagues Petrzhak performed a series of precision absolute measurements of induced fission, caused by neutrons, which have monoenergy as well as fission-spectrum neutrons.^[6] 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 awarded Doctor of Sciences in 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] Konstantin Petrzhak published articles on fission products from nuclear reactors^[41] until his death in 1998. He died on October 10, 1998, and was buried at Serafimovskoe Cemetery in Saint Petersburg.

Personal life

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.

Awards

1946 Stalin Prize (2nd degree; jointly with Georgy Flyorov for discovery of spontaneous fission; 100000 Soviet rubles each;^[42])
1950 Council of Ministers Prize (for work on fulfillment of governmental tasks)
1953 Stalin Prize (for work on soviet atomic project)
1953 Order of the Red Banner of Labour (for work on soviet atomic project)
1957 Presidium of Academy of Sciences of the Soviet Union Prize

Selected works

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.
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, 238}U, ²³⁷Np, ^{239, 242}Pu 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.{{cite book}}: CS1 maint: location missing publisher (link)
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.

Notes

^ Константин Антонович Петржак (Konstantin Pietrzak). Ядерная физика в Интернете (in Russian). Retrieved November 10, 2014.
^ Petrzhak KA, Flerov GN (1940). "Spontaneous fission of uranium". Proc USSR Acad Sci. 28 (6): 500.
^ ^a ^b "Konstantin Antonovich Petrzhak". www.npd.ac. Moskva: RuHEP-NP. 10 October 1998. Retrieved 20 July 2018.
^ ^a ^b ^c ^d ^e ^f ^g "Konstantin Petrzhak" Константин Петржак. Russian Engineers (in Russian). 2010. Archived from the original on 2014-10-22.
^ ^a ^b ^c ^d ^e Холодная, Варвара (5 June 2009). Не пропусти! [Do not miss]. Вечерний Петербург (in Russian). Vol. 102, no. 23946. Retrieved December 22, 2014.
^ ^a ^b ^c ^d 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.
^ ^a ^b Асташенков 1968, p. 92.
^ Konstantin Petrzhak obituary
^ 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.
^ 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.
^ ^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.
^ 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.
^ Отто Ган [Otto Hahn] (in Russian). Archived from the original on 2015-09-25.
^ ^a ^b Асташенков 1968, p. 93.
^ ^a ^b Мухин 1974, p. 477.
^ Oganessian, Yuri (2003). Г. Н. Флёров. Молодые годы [G. Flyorov. Early years] (DOC) (in Russian).
^ Кузнецова, Р.В. Многослойная ионизационная камера [Multilayer ionization chamber]. Приборы и инструменты России (in Russian). p. 15.
^ Мухин 1974, p. 478.
^ Flerov GN, Petrzhak KA (1961). Спонтанное деление ядер [Spontaneous fission of nuclei] (PDF). Physics-Uspekhi (in Russian). LXXIII (4): 657.
^ Асташенков 1968, p. 96.
^ Paul Kuroda (2012). The Origin of the Chemical Elements and the Oklo Phenomenon. Springer Science & Business Media. p. 32. ISBN 978-3642686672.
^ Открытие спонтанного деления урана [Discovery of spontaneous fission in uranium] (in Russian).
^ 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.
^ 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.
^ "Works on creation of the first atomic bomb in USSR" Создание первой атомной бомбы в СССР [Works on creation of the first atomic bomb in USSR]. BioFile.ru (in Russian). Archived from the original on 2013-08-08.
^ 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.
^ ^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.
^ РФЯЦ-ВНИИЭФ 2000, p. 426.
^ 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.
^ Крюков, С.Г. Достоин ли А. Сахаров почестей? [Whether A. Sakharov is worth ceremonial?]. Своими именами (in Russian). Retrieved October 31, 2014.
^ 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. Archived from the original (PDF) on 2018-07-13. Retrieved 2015-09-17.
^ Выпускники и преподаватели [Alumni and Faculty]. Saint Petersburg State Institute of Technology (in Russian). Archived from the original on 2019-02-05. Retrieved 2014-10-17.
^ История кафедры [History of department]. Saint Petersburg State Institute of Technology (in Russian). Archived from the original on 2017-07-03. Retrieved 2014-10-17.
^ 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.
^ 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.
^ Петржак, К.А.; Кондратько, М.Я.; Никотин, О.П.; Теплых, В.Ф. (1963). Запаздывающие нейтроны при фотоделении тяжелых ядер [Delayed neutrons during photofission]. Атомная энергия (in Russian). 15: 157–158.
^ 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). Vol. 4. Обнинск. pp. 13–17.{{cite book}}: CS1 maint: location missing publisher (link)
^ Dushin, V. N.; Fomichev, A. V.; Kovalenko, S. S.; et al. (1983). "Statistical analysis of experimental data on the cross sections of ^{233, 235, 238}U, 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.
^ 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).
^ "Members of Nuclear Physics Division of Physical Sciences Department of Russian Academy of Sciences". High Energy and Nuclear Physics in Russia.
^ 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.
^ "Russian discovery of atomic secrets". The Canberra Times. Vol. 20, no. 5869. January 29, 1946. p. 1.

References

Асташенков, Петр Тимофеевич (1968). Курчатов [Kurchatov]. М.: Молодая гвардия. p. 24.
Мухин, К.Н. (1974). Экспериментальная ядерная физика [Experimental nuclear physics] (in Russian). Vol. 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). Vol. II. Москва-Саров: РФЯЦ-ВНИИЭФ. ISBN 5-85165-402-3.

[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.

[RuHEP-NP-3] "Konstantin Antonovich Petrzhak". www.npd.ac. Moskva: RuHEP-NP. 10 October 1998. Retrieved 20 July 2018.

[rus-eng-4] ^ ^a ^b ^c ^d ^e ^f ^g "Konstantin Petrzhak" Константин Петржак. Russian Engineers (in Russian). 2010. Archived from the original on 2014-10-22.

[Вечерний_Петербург-5] Холодная, Варвара (5 June 2009). Не пропусти! [Do not miss]. Вечерний Петербург (in Russian). Vol. 102, no. 23946. Retrieved December 22, 2014.

[Семейные_истории-6] 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.

[FOOTNOTEАсташенков196892-7] Асташенков 1968, p. 92.

[obituary-8] 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.

[Kurchatov-11] 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.

[Yale_University_Press,_Holloway,_1994-12] 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.

[FOOTNOTEАсташенков196893-14] Асташенков 1968, p. 93.

[FOOTNOTEМухин1974477-15] 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.

[FOOTNOTEМухин1974478-18] 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.

[FOOTNOTEАсташенков196896-20] 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] "Works on creation of the first atomic bomb in USSR" Создание первой атомной бомбы в СССР [Works on creation of the first atomic bomb in USSR]. BioFile.ru (in Russian). Archived from the original on 2013-08-08.

[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.

[Grand_piano-27] 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.

[FOOTNOTEРФЯЦ-ВНИИЭФ2000426-28] 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. Archived from the original (PDF) on 2018-07-13. Retrieved 2015-09-17.

[32] Выпускники и преподаватели [Alumni and Faculty]. Saint Petersburg State Institute of Technology (in Russian). Archived from the original on 2019-02-05. Retrieved 2014-10-17.

[33] История кафедры [History of department]. Saint Petersburg State Institute of Technology (in Russian). Archived from the original on 2017-07-03. Retrieved 2014-10-17.

[34] 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.

[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]. Атомная энергия (in Russian). 15: 157–158.

[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). Vol. 4. Обнинск. pp. 13–17.{{cite book}}: CS1 maint: location missing publisher (link)

[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, 238}U, 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] 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.

[42] "Russian discovery of atomic secrets". The Canberra Times. Vol. 20, no. 5869. January 29, 1946. p. 1.

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+{{Short description|Russian nuclear physicist}}
-{{Refimprove|date=October 2014}}
+{{expand Russian|topic=bio|Петржак, Константин Антонович|date=September 2014}}
-{{Other people2|Pietrzak}}
 {{Infobox scientist
-| name        = Konstantin Petrzhak
+| name              = Konstantin Petrzhak
-| native_name = Константин Антонович Петржак
+| native_name       = Константин Антонович Петржак
-| native_name_lang = ru
+| native_name_lang  = ru
-| image       = Konstantin Petrzhak.jpg
+| image             = Konstantin Petrzhak.jpg
+| image_size        =
-| birth_date  =  {{birth date |1907|9|7|mf=y}}
+| alt               =
-| birth_place = [[Łuków]], [[Poland]]
+| caption           = K. A.  Petrzhak, photo from the archive of Radium Institute
-| death_date  = {{death date and age |1998|10|10 |1907|09|07}}
+| birth_name        = Konstantin Antonovich Petrzhak
-| death_place = [[Russia]]
-| residence   = {{ublist |[[USSR]] |[[Russia]]}}
+| birth_date        = {{birth date|1907|9|4|mf=y}}
+| birth_place       = [[Łuków]], [[Siedlce Governorate]], [[Congress Poland|Poland]] in [[Russian Empire]]<br>({{small|(Present-day, Łuków in [[Poland]])}}
-| nationality = [[Poles|Pole]]
+| death_date        = {{death date and age|1998|10|10|1907|9|4|mf=y}}
-| fields      = [[Physics]] ([[Nuclear physics|nuclear]])
+| death_place       = [[Saint Petersburg]], [[Russia]]
-| workplaces  = {{ublist |[[V. G. Khlopin Radium Institute|Khlopin Radium Institute]] |[[Saint Petersburg State Institute of Technology]]}}
+| resting_place     =
-| alma_mater  = [[Saint Petersburg State University]]
+| resting_place_coordinates = <!--{{coord|LAT|LONG|type:landmark|display=inline,title}}-->
-| thesis_title =  <!--(or  | thesis1_title =  and  | thesis2_title = )-->
+| other_names       =
-| thesis_url  =   <!--(or  | thesis1_url  =   and  | thesis2_url  =  )-->
+| citizenship       = {{RUS}}
-| thesis_year =   <!--(or  | thesis1_year =   and  | thesis2_year =  )-->
+| nationality       = [[Polish minority in Russia|Polish]]
-| doctoral_advisor = [[Igor Kurchatov]]
-| academic_advisors = [[Vitaly Khlopin]]
+| fields            = [[Physics]]
+| workplaces        = [[V. G. Khlopin Radium Institute|Khlopin Radium Institute]]
-| known_for   = {{longitem|Discovery of [[spontaneous fission]]}}
-| awards      = {{Order of the Badge of Honour}}
+| patrons           =
+| alma_mater        = [[Leningrad State University]]
+| thesis_title      = Study of thorium and samarium radioactivity
+| thesis_url        = <!--(or  | thesis1_url  =   and  | thesis2_url  =  )-->
+| thesis_year       = 1948
+| doctoral_advisor  = <!--(or  | doctoral_advisors = )-->
+| academic_advisors =
+| doctoral_students =
+| notable_students  =
+| known_for         = Discovery of [[spontaneous fission]]<br>[[Soviet nuclear program|Soviet atomic bomb project]]
+| awards            = [[USSR State Prize|Stalin Prize]] {{small|(1950)}}
+| author_abbrev_bot =
+| author_abbrev_zoo =
+| spouse            = <!--(or | spouses = )-->
+| partner           = <!--(or | partners = )-->
+| children          =
+| signature         = <!--(filename only)-->
+| signature_alt     =
+| website           = <!--{{URL|www.example.com}}-->
+| footnotes         =
 }}
-'''Konstantin Petrzhak''' ({{lang-rus|Константи́н Анто́нович Петржак|p=kənstɐnʲˈtʲin ɐnˈtonɐvɪt͡ɕ pʲɛtʐak}}; 1907-1998) was a Soviet physicist of [[Poles|Polish]] origin. He discovered [[spontaneous fission]] of uranium jointly with [[Georgy Flyorov]] in 1940.<ref>{{cite journal |author=Flerov GN, Petrzhak KA|year=1940 |title=Spontaneous fission of uranium |journal=[[Proceedings of the USSR Academy of Sciences|Proc USSR Acad Sci]] |issue=28 |pages=500 }}</ref>
+'''Konstantin Antonovich Petrzhak''' (alternatively '''Pietrzak''';<ref>{{cite web |url=http://nuclphys.sinp.msu.ru/persons/pages/petrzhak_konstantin.htm |script-title=ru:Константин Антонович Петржак (Konstantin Pietrzak) |website=Ядерная физика в Интернете |language=ru|access-date=November 10, 2014}}</ref> {{lang-rus|Константи́н Анто́нович Пе́тржак|p=kənstɐnʲˈtʲin ɐnˈtonəvʲɪtɕ ˈpʲedʐək}}, {{IPA|pl|ˈpjɛt.ʂak|lang}}; 4 September 1907– 10 October 1998), {{small|[[Doctor of Sciences|D.Sc.]]}}, was a Russian [[Physics|physicist]] of [[Polish people|Polish origin]], and a professor of physics at the [[Saint Petersburg State University]].
+Receiving credit with [[Georgy Flyorov]], a physicist, for the fundamental discovery of [[spontaneous fission]] of [[uranium]] in 1940, Petrzhak's career in physics was then spent mostly in the former [[Soviet atomic bomb project|Soviet program of nuclear weapons]].<ref>{{cite journal |vauthors=Petrzhak KA, Flerov GN |year=1940 |title=Spontaneous fission of uranium |journal=[[Proceedings of the USSR Academy of Sciences|Proc USSR Acad Sci]] |issue=6|volume=28 |pages=500}}</ref> Konstantin Petrzhak was among of Soviet pioneers in nuclear physics research.<ref name="RuHEP-NP"/>
 == Biography ==
+===Early and personal life===
-Konstantin Petrzhak was born on 3 September 1907 in [[Łuków]] ([[Congress Poland]], Russian Empire, now in [[Poland]]). Antoni Petrzhak was his father. In 1936 he graduated from [[Saint Petersburg State University]]. Later he wrote thesis at [[V. G. Khlopin Radium Institute|Khlopin Radium Institute]] in Saint Petersburg (which was named First Radium Institute at that time). [[Vitaly Khlopin]] and [[Igor Kurchatov]] were his scientific advisors. From 1939 to 1940 he and [[Georgy Flyorov]] tried to detect [[spontaneous fission]] under general supervision of Igor Kurchatov. In 1939 the experiments were carried out in Saint Petersburg. In 1940 they were verified in Moscow in an underground lab under [[Dinamo (Moscow Metro)|Dinamo station]] of Moscow Metro. They constructed a highly sensitive [[ionization chamber]] to detect uranium debris.<ref>{{cite web |url=http://flerovlab.jinr.ru/linkc/flerov/doc/%D0%A4%D0%BB%D1%91%D1%80%D0%BE%D0%B2%20(%D0%B1%D0%B8%D0%BE%D0%B3%D1%80%D0%B0%D1%84%D0%B8%D1%8F)%20%D1%81%D1%82%D0%B0%D1%82%D1%8C%D1%8F%20%D0%B2%20%D0%94%D1%83%D0%B1%D0%BD%D1%83.doc| title=G. Flyorov. Early years |script-title=ru:Г. Н. Флёров. Молодые годы |format=DOC|last=Oganessian |first=Yuri |authorlink=Yuri Oganessian |year=2003 |language=ru|}}</ref> The ionization chamber had electrodes in it with the total square of about 1000 cm<sup>2</sup>.<ref>{{cite web |url=http://files.school-collection.edu.ru/dlrstore/bab9ee0a-7e14-4561-890b-b29ca67435ce/KameraMnogoslojnajaIonizacionnaja-opis.htm |title=Multilayer ionization chamber |script-title=ru:Многослойная ионизационная камера |last=Кузнецова|first=Р.В.|language=ru|page=15|website=Приборы и инструменты России}}</ref> The samples of uranium were placed inside the chamber.<ref name=ufn>{{cite journal |author=Flerov GN, Petrzhak KA|year=1961 |title=Спонтанное деление ядер| trans-title =Spontaneous fission of nuclei | language = Russian |url=http://nuclphys.sinp.msu.ru/UFN/r614f.pdf |journal=Physics-Uspekhi |volume=LXXIII |issue=4 |pages=657 |pmc= }}</ref> The detector was checked while measuring background.<ref name=ufn/> When the source of neutrons was taken away the detector still detected particles. Then they assumed that spontaneous fission was discovered.<ref>{{cite web |url=http://hirosima.scepsis.ru/library/lib_27.html |title=Stalin and the Bomb |script-title=Сталин и бомба |last=Holloway |first= David |language=ru |isbn=0300066643}}</ref> 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".<ref>{{cite web |url=http://www.aes1.ru/mission/dates/d11 |title=Discovery of spontaneous fission in uranium |script-title=Открытие спонтанного деления урана |language=ru}}</ref><ref>{{cite web |url=http://ross-nauka.narod.ru/04/04-033.html |title=Flerov, Petrzhak - Scientific discovery №33. Spontaneous fission of uranium |script-title=ru:Флеров, Петржак – Научное открытие №33 Спонтанное деление ядер урана |accessdate=2014-10-24 |website=Научные открытия России| language =ru}}</ref>
+Konstantin Petrzhak was born in [[Łuków]], [[Congress Poland|Poland]] in [[Russian Empire]], on 4 September 1907.<ref name="RuHEP-NP">{{cite web |title=Konstantin Antonovich Petrzhak |url=http://www.npd.ac.ru/obituary/petrzhak.htm |website=www.npd.ac |publisher=RuHEP-NP |access-date=20 July 2018 |location=Moskva |language=en |date=10 October 1998}}</ref><ref name=rus-eng>{{cite web |url=http://rus-eng.org/eng/Petrzhak%20Konstantin%20Antonovich.htm |title=Konstantin Petrzhak|script-title=ru:Константин Петржак|year=2010|website=Russian Engineers |language=ru|url-status=dead|archive-url=https://web.archive.org/web/20141022104515/rus-eng.org/eng/Petrzhak%20Konstantin%20Antonovich.htm|archive-date=2014-10-22}}</ref> Other Russian documented sources noted his birthplace in Dombrovo in [[Kaliningrad Oblast|Kaliningrad]] with same birth date.<ref name="rus-eng"/> 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.<ref name="rus-eng"/> In 1928, Petrzhak was sent to attend the trade school, ''[[Rabfak]]'', that was affiliated with the [[Saint Petersburg State University|Leningrad State University]], where he studied [[painting]] which remained his lifelong passion.<ref name="Вечерний Петербург">{{cite news |last=Холодная |first=Варвара |date=5 June 2009 |script-title=ru:Не пропусти! |trans-title=Do not miss|url=http://www.vppress.ru/stories/4525 |language=ru |newspaper=Вечерний Петербург |issue=23946 |access-date=December 22, 2014|volume=102 }}</ref> 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.<ref name="Вечерний Петербург"/> He also learned to play the [[Classical music|music]] and was an amateur [[violin]]ist and [[Guitarist|guitar player]].<ref name="Вечерний Петербург"/>
+Peterzhak went to the Leningrad State University worked with the research group at the university in 1931.<ref name="Семейные истории">{{cite web |url=http://www.famhist.ru/famhist/tanki/0008092f.htm |script-title=ru:К 100-летию со дня рождения К.А. Петржака|trans-title=To 100-year anniversary of K. A. Petrzhak|last1=Драпчинский |first1=Л.В. |website=Семейные истории |access-date=October 31, 2014}}</ref> In November 1936, Pertzhak eventually earned his [[diploma]] certified under [[Igor Kurchatov]]{{sfn|Асташенков|1968|p=92}} from the Leningrad State University.<ref name="Семейные истории"/>
-In 1940 Konstantin Petrzhak was suggested to enter the leading team of [[soviet atomic bomb project]].<ref>{{cite web |url=http://biofile.ru/his/528.html |title=Works on creation of the first atomic bomb in USSR |script-title=Создание первой атомной бомбы в СССР |website="BioFile.ru" |language=ru}}</ref> He is rumoured to participate in soviet atomic project.
+Konstantin Petrzhak married Galina Ivanovna Mitrofanova (b. 1918), also a radiochemist.<ref name="Вечерний Петербург"/>
-When the USSR entered the World War II Petrzhak was eligible for serving in the army. If he was awarded the Stalin Prize he could avoid entering the regular army. The Academy of Sciences of USSR nominated him to receive this prize in early 1940s. But he didn't receive the prize. So during World War II Petrzhak served in military intelligence.<ref>{{cite book |last=Зенькович |first=Николай |date=2004 |title=Тайны ушедшего века. Власть. Распри. Подоплека |trans_title=Mysteries of the passing century. Power. Arguements. Causes. |url=http://books.google.by/books?id=3oVYMfHhrnEC&pg=PA204&lpg=PA204&dq=%D0%9F%D0%B5%D1%82%D1%80%D0%B6%D0%B0%D0%BA+%D0%91%D0%BE%D0%BC%D0%B1%D0%B0&source=bl&ots=RDQWEMt0tj&sig=tDe4kMzVR1LW2waRJ-lHYmJuAu4&hl=be&sa=X&ei=yD5GVOuJBNjiat7jgdAO&ved=0CFgQ6AEwCA#v=onepage&q&f=false |language=ru |location=Moscow |publisher=ОЛМА Медиа Групп |isbn=5224046769 |accessdate=October 22, 2012 }}</ref>
+In 1934, Petrzhak found a job at the [[V. G. Khlopin Radium Institute|Khlopin Radium Institute]] located in the State University in [[Saint Petersburg]] (First Radium Institute), which was directed by Igor Kurchatov, a nuclear physicist.{{sfn|Асташенков|1968|p=92}}
-Konstantin Petrzhak founded a laboratory of neutron physics and physics of fission in Khlopin Radium Institute in 1947 and was the head of this laboratory until 1986.<ref name=rus-eng>{{cite web |url=http://rus-eng.org/eng/Petrzhak%20Konstantin%20Antonovich.htm |title=Konstantin Petrzhak|script-title=ru:Константин Петржак|year=2010|website=Russian Engineers |series= |publisher= |at= |language=ru}}</ref> Later he was one of the founders of Engineering faculty of [[Saint Petersburg State Institute of Technology]].<ref>{{cite web |url=http://www1.lti-gti.ru/museum/%D0%92%D1%8B%D0%BF%D1%83%D1%81%D0%BA%D0%BD%D0%B8%D0%BA%D0%B8%20%D0%A2%D0%98%20%D0%B8%20%D0%BA%D1%83%D0%BB%D1%8C%D1%82%D1%83%D1%80%D0%B0.htm |title=Alumni and Faculty |script-title=ru:Выпускники и преподаватели |website=Saint Petersburg State Institute of Technology |publisher= |at= |language=ru }}</ref> There he founded a department of nuclear physics in 1949<ref name=rus-eng/> and was the head of it for 22 years.<ref>{{cite web |url=http://technolog.edu.ru/ru/faculties/engineering-and-technological/kafedry-5-fakulteta/kafedra-radiatsionnoj-tekhnologii/%D0%B8%D1%81%D1%82%D0%BE%D1%80%D0%B8%D1%8F-%D0%BA%D0%B0%D1%84%D0%B5%D0%B4%D1%80%D1%8B.html |title=History of department |script-title=История кафедры |website=Saint Petersburg State Institute of Technology |language=ru }}</ref> In 1961 he founded a laboratory of nuclear energy there. Konstantin Petrzhak created an express method of detection of plutonium and satellite radioative elements in samples of irradiated uranium.<ref name=rus-eng/> He was awarded [[USSR State Prize|Stalin prize]] in 1946 (jointly with [[Georgy Flyorov]] for discovery of spontaneous fission) and in 1953. He died on October 10, 1998 and was buried in Saint Petersburg.
+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."<ref name=obituary>[http://www.ruhep.ru/obituary/petrzhak.htm Konstantin Petrzhak obituary]</ref><ref>{{cite book |last1=Гринберг |first1=А.П. |last2=Френкель |first2=В.Я. |year=1984|title=Igor Vasilyevich Kurchatov in Ioffe Institute (1925-1943)|script-title=ru:Игорь Васильевич Курчатов в Физико-техническом институте (1925-1943 гг.) |url=http://physiclib.ru/books/item/f00/s00/z0000027/st040.shtml |location=Ленинград |publisher=Наука |pages=181 |access-date=November 12, 2014 }}</ref><ref>{{cite book |last=Иоффе |first=А. Ф. |year=1985 |script-title=ru:О физике и физиках |trans-title=About physics and physicists|chapter=Открытие молодых советских ученых |chapter-url=http://alexandr4784.narod.ru/ioffe/ioffe_1_10.pdf|edition=2 |location=Ленинград. |publisher=Наука. Ленинградское отделение |access-date=October 31, 2014|series=Наука. Мировоззрение. Жизнь }}</ref><ref name=Kurchatov>{{Cite journal|author=Гапонов Ю. В. |url=http://nuclphys.sinp.msu.ru/radioactivity/ract07.htm|script-title=ru:Игорь Васильевич Курчатов (1903-1960). Жизненный путь (К столетию со дня рождения)|trans-title=Igor Vasilievich Kurchatov (1903-1960). Life way (to 100th anniversary) |journal=Физика элементарных частиц и атомного ядра|year=2003|volume=34|issue=3|pages=530}}</ref>
+===Soviet program of nuclear weapons and academia===
+In 1939, Kurchatov was assigned research under Georgy Flyorov and Petrzhak to conduct investigation on uranium fission induced by neutrons of different energy levels, following [[Yakov Frenkel]]'s theory of fission.{{rp|54}}<ref name="Yale University Press, Holloway, 1994">{{cite book |last1=Holloway |first1=David |title=Stalin and the Bomb: The Soviet Union and Atomic Energy, 1939-1956 |date=1994 |publisher=Yale University Press |isbn=0300066643 |pages=450 |chapter-url=https://books.google.com/books?id=ICO6aUnQ2KcC&pg=PA54 |access-date=24 July 2018 |language=en |chapter-format=google books |chapter={{small|§(Reacting to Fission)}}}}</ref><ref>{{Cite web|url=http://allreferat.org.ua/referat/71686/referat_from_site_www.allreferat.org.ua_.rtf|language=ru|script-title=ru:Отто Ган|trans-title=Otto Hahn|url-status=dead|archive-url=https://web.archive.org/web/20150925073446/http://allreferat.org.ua/referat/71686/referat_from_site_www.allreferat.org.ua_.rtf|archive-date=2015-09-25}}</ref> Earlier, Flyorov and his assistant Tatiana I. Nikitinskaya had already made an ionization chamber to detect heavy particles, and were directed to increase the sensitivity of the ionization chamber.{{sfn|Асташенков|1968|p=93}}{{sfn|Асташенков|1968|p=93}} The team created a multilayer [[ionization chamber]] to detect [[decay product]]s originating from the fission of uranium.{{sfn|Мухин|1974|p=477}}<ref>{{cite web |url=http://flerovlab.jinr.ru/linkc/flerov/doc/%D0%A4%D0%BB%D1%91%D1%80%D0%BE%D0%B2%20(%D0%B1%D0%B8%D0%BE%D0%B3%D1%80%D0%B0%D1%84%D0%B8%D1%8F)%20%D1%81%D1%82%D0%B0%D1%82%D1%8C%D1%8F%20%D0%B2%20%D0%94%D1%83%D0%B1%D0%BD%D1%83.doc| trans-title=G. Flyorov. Early years |script-title=ru:Г. Н. Флёров. Молодые годы |format=DOC|last=Oganessian |first=Yuri |author-link=Yuri Oganessian |year=2003 |language=ru}}</ref>
+The ionization chamber utilized electrodes with a total surface area of about 1000&nbsp;cm<sup>2</sup>.<ref>{{cite web |url=http://files.school-collection.edu.ru/dlrstore/bab9ee0a-7e14-4561-890b-b29ca67435ce/KameraMnogoslojnajaIonizacionnaja-opis.htm |trans-title=Multilayer ionization chamber |script-title=ru:Многослойная ионизационная камера |last=Кузнецова|first=Р.В.|language=ru|page=15|website=Приборы и инструменты России}}</ref> The chamber's 15 plates{{sfn|Мухин|1974|p=478}} were covered with uranium oxide with approximate surface density of 10–20&nbsp;mg/cm<sup>2</sup>.{{sfn|Мухин|1974|p=477}} The detector compared particle activity to a background level control.<ref>{{cite journal |author=Flerov GN, '''Petrzhak KA'''|year=1961 |script-title=ru:Спонтанное деление ядер| trans-title =Spontaneous fission of nuclei | language=ru |url=http://nuclphys.sinp.msu.ru/UFN/r614f.pdf |journal=Physics-Uspekhi |volume=LXXIII |issue=4 |pages=657 }}</ref> 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&nbsp;cm<sup>2</sup>. 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 (Moscow Metro)|Dinamo station]] of Moscow Metro (about 50 m below the earth surface){{sfn|Асташенков|1968|p=96}} in an attempt to rule out the effects of cosmic rays. In May 1940, they were confident that they had discovered spontaneous fission.<ref>{{cite book |url=https://books.google.com/books?id=Gav7CAAAQBAJ&pg=PA32 |title=The Origin of the Chemical Elements and the Oklo Phenomenon|author=Paul Kuroda |isbn=978-3642686672|year=2012|publisher=Springer Science & Business Media|pages=32|author-link=Paul Kuroda}}</ref> 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".<ref>{{cite web |url=http://www.aes1.ru/mission/dates/d11 |trans-title=Discovery of spontaneous fission in uranium |script-title=ru:Открытие спонтанного деления урана |language=ru}}</ref><ref>{{cite web |url=http://ross-nauka.narod.ru/04/04-033.html |trans-title=Flerov, Petrzhak - Scientific discovery №33. Spontaneous fission of uranium |script-title=ru:Флеров, Петржак – Научное открытие №33 Спонтанное деление ядер урана |access-date=October 24, 2014|website=Научные открытия России| language =ru |archive-url=https://web.archive.org/web/20120125194736/http://ross-nauka.narod.ru/04/04-033.html|archive-date=25 January 2012}}</ref> Later, the discovery of spontaneous fission was confirmed by [[Otto Robert Frisch]].<ref>{{cite journal|script-title=ru:О создании первой отечественной атомной бомбы|pages=83|trans-title=About the creation of the first national atomic bomb|author=Гончаров Г. А. |author2=Рябев Л. Д.|journal=УФН|year=2001|volume=171|number=1|language=ru|url=http://elibrary.lt/resursai/Uzsienio%20leidiniai/Uspechi_Fiz_Nauk/2001/N01/2001-1-03.pdf}}</ref>
+In 1940, Petrzhak was recommended for the top team in the [[Soviet atomic bomb project]].<ref>{{cite web |url=http://biofile.ru/his/528.html |trans-title=Works on creation of the first atomic bomb in USSR |script-title=ru:Создание первой атомной бомбы в СССР |website=BioFile.ru |language=ru|title=Works on creation of the first atomic bomb in USSR|url-status=dead|archive-url=https://web.archive.org/web/20130808012825/biofile.ru/his/528.html|archive-date=2013-08-08}}</ref> 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 [[Academy of Sciences of the Soviet Union]] nominated him for the award, which he did not receive.<ref>{{cite book |last=Губарев |first=B.C. |year=2000 |script-title=ru:XX век. Исповеди: судьба науки и ученых в России.|trans-title=20th century. Confessions: the destiny of science and scientists of Russia. |url=http://textarchive.ru/c-2437582-p3.html |language=ru|location=М. |publisher=[[МАИК "Наука/Интерпериодика"]] |isbn=5-7846-0034-6 |access-date=October 31, 2014}}</ref> Sources disagree on whether Petrzhak volunteered,<ref name="Kurchatov" /> or was drafted<ref name="Grand piano">{{cite web |url=http://ugservis23.ru/library/rojal-jemocij/tvorcy-ch-170.html |script-title=ru:Рояль эмоций, Творцы - ч. 170|trans-title=Grand piano of emotions. Creators, part 170|language=ru|access-date=October 31, 2014|archive-url=https://web.archive.org/web/20141031105734/http://ugservis23.ru/library/rojal-jemocij/tvorcy-ch-170.html|archive-date=October 31, 2014}}</ref> into the army.
+Petrzhak served in the military intelligence company of a [[Close-in weapon system|CIWS]] regiment first as a junior lieutenant,{{sfn |РФЯЦ-ВНИИЭФ|2000|p=426}} and later as a senior lieutenant.<ref>{{cite book |last=Зенькович |first=Николай |date=2004 |script-title=ru:Тайны ушедшего века. Власть. Распри. Подоплека |trans-title=Mysteries of the passing century. Power. Arguments. Causes. |url=https://books.google.com/books?id=3oVYMfHhrnEC&pg=PA204 |language=ru |location=Moscow |publisher=ОЛМА Медиа Групп |isbn=5224046769 |access-date=October 22, 2014 }}</ref><ref>{{cite web |url=http://svoim.info/201118/?18_7_1 |script-title=ru:Достоин ли А. Сахаров почестей?|trans-title=Whether A. Sakharov is worth ceremonial? |last1=Крюков |first1=С.Г. |website=Своими именами |language=ru|access-date=October 31, 2014}}</ref> On 28 June 1941, he participated in the battle of [[Karelian Isthmus]]. Later, he fought in [[Volkhov Front]].<ref name="Grand piano" /> On 20th of March 1942 he was ordered to leave the army<ref name="Семейные истории"/> and join evacuated Radium Institute scientists in Kazan.
+In 1943, Petrzhak studied neutron induced fission of uranium under the supervision of professor [[Pyotr Lukirsky]]. 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,<ref name="rus-eng" /> when he became a part-time contractor.
+In 1949, Petrzhak was appointed a member of the Uranium Commission of the Soviet Academy of Sciences.<ref>{{cite journal|journal=Известия Санкт-Петербургского государственного технологического института|volume=4|issue=30|year=2008|pages=80|url=http://science.spb.ru/files/IzvetiyaTI/2008/4/Full/files/assets/downloads/publication.pdf|author1=А.С. Дудырев|author2=А.А. Копырин|author3=Б.А. Лавров|author4=А.А. Малыгин|author5=В.Н. Нараев|author6=А.А. Персинен|author7=В.И. Штанько|trans-title=High technologies at the beginning of 21st century|script-title=ru:Наукоемкие технологии в начале XXI века|language=ru|access-date=2015-09-17|archive-date=2018-07-13|archive-url=https://web.archive.org/web/20180713120732/http://science.spb.ru/files/IzvetiyaTI/2008/4/Full/files/assets/downloads/publication.pdf|url-status=dead}}</ref> He was one of the founders of the Engineering faculty of the [[Saint Petersburg State Institute of Technology]].<ref>{{cite web |url=http://www1.lti-gti.ru/museum/%D0%92%D1%8B%D0%BF%D1%83%D1%81%D0%BA%D0%BD%D0%B8%D0%BA%D0%B8%20%D0%A2%D0%98%20%D0%B8%20%D0%BA%D1%83%D0%BB%D1%8C%D1%82%D1%83%D1%80%D0%B0.htm |trans-title=Alumni and Faculty |script-title=ru:Выпускники и преподаватели |website=Saint Petersburg State Institute of Technology |language=ru |access-date=2014-10-17 |archive-date=2019-02-05 |archive-url=https://web.archive.org/web/20190205120044/http://www1.lti-gti.ru/museum/%D0%92%D1%8B%D0%BF%D1%83%D1%81%D0%BA%D0%BD%D0%B8%D0%BA%D0%B8%20%D0%A2%D0%98%20%D0%B8%20%D0%BA%D1%83%D0%BB%D1%8C%D1%82%D1%83%D1%80%D0%B0.htm |url-status=dead }}</ref> Petrzhak founded the Saint Petersburg State Institute of Technology department of nuclear physics in 1949,<ref name="rus-eng" /> and remained its chair for 22 years.<ref>{{cite web |url=http://technolog.edu.ru/ru/faculties/engineering-and-technological/kafedry-5-fakulteta/kafedra-radiatsionnoj-tekhnologii/%D0%B8%D1%81%D1%82%D0%BE%D1%80%D0%B8%D1%8F-%D0%BA%D0%B0%D1%84%D0%B5%D0%B4%D1%80%D1%8B.html |trans-title=History of department |script-title=ru:История кафедры |website=Saint Petersburg State Institute of Technology |language=ru |access-date=2014-10-17 |archive-date=2017-07-03 |archive-url=https://web.archive.org/web/20170703190635/http://technolog.edu.ru/ru/faculties/engineering-and-technological/kafedry-5-fakulteta/kafedra-radiatsionnoj-tekhnologii/%D0%B8%D1%81%D1%82%D0%BE%D1%80%D0%B8%D1%8F-%D0%BA%D0%B0%D1%84%D0%B5%D0%B4%D1%80%D1%8B.html |url-status=dead }}</ref> Hundreds of graduates of Engineering faculty studied under his supervision, he was also a scientific supervisor of dozens of Candidates of Science and Doktors of Science.<ref name=rus-eng/>
+Konstantin Petrzhak created an express method to detect plutonium and associated radioisotopes in samples of irradiated uranium.<ref name="rus-eng" /> In 1960s he and his colleagues studied fission with simultaneous emission of protons, [[Tritium|tritons]] and [[alpha-particle]]s.<ref>{{cite journal |vauthors=Adamov VM, Drapchinsky LV, Kovalenko SS, Petrzhak KA, Pleskachevsky LA, Tyutyugin II |year=1974 |title=Polar light particle emission in spontaneous fission of <sup>252</sup>Cf |journal=Physics Letters B |volume=48 |issue=4 |pages=311–314 |doi=10.1016/0370-2693(74)90597-8 |bibcode=1974PhLB...48..311A }}</ref> In 1960s jointly with the colleagues Petrzhak performed a series of precision absolute measurements of induced fission, caused by neutrons, which have monoenergy as well as fission-spectrum neutrons.<ref name="Семейные истории"/> From 1963 to 1976, he published a series of articles on the measurement of photofission.<ref>{{Cite journal|first1= M. Ya. |last1=Kondrat'ko |first2=V. N. |last2=Korinets |first3=K. A. |last3=Petrzhak|title=Dependence of asymmetry in the photofission of <sup>233</sup>U and <sup>239</sup>Pu on the maximum bremsstrahlung|journal=Soviet Atomic Energy|year=1976|volume=40|issue=1|pages=83–84|doi=10.1007/BF01119404|s2cid=101875009 }}</ref><ref>{{Cite journal|script-title=ru:Запаздывающие нейтроны при фотоделении тяжелых ядер |url=http://elib.biblioatom.ru/text/atomnaya-energiya_t15-2_1963/go,52/|trans-title=Delayed neutrons during photofission|author=Петржак, К.А. |author2=Кондратько, М.Я. |author3=Никотин, О.П. |author4=Теплых, В.Ф. |language=ru |year=1963|volume=15|pages=157–158|journal=Атомная энергия}}</ref> 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<ref>{{Cite book|last1=Алхазов |first1=И.Д. |last2=Касаткин |first2=В.П |last3=Косточкин |first3= О.И.|last4=Малкин |first4=Л.З. |last5=Сорокина |first5=A.B. |last6=Петржак |first6=К.А. |last7=Фомичёв |first7=A.B. |last8=Шпаков |first8=В.И. |last9=Румянцев |first9=Б.В. |author10=Соколов A.M. |display-authors=3|chapter=Измерение сечения деления 238U нейтронами с энергией 14,6 МэВ|trans-chapter=Measurements of cross-sections of U-238 fission when irradiated with neutrons of energy 14.5 MeV|script-title=ru:Нейтронная физика, Материалы II Всесоюзной конференции по нейтронной физике, Киев, 1973|trans-title=Neutron physics, proceedings of II USSR conference on neutron physics, Kiev, 1973 |language=ru |place=Обнинск|year=1974|volume=4|pages=13–17}}</ref><ref>{{cite journal|last1=Dushin|first1=V. N.|last2=Fomichev|first2=A. V. |last3=Kovalenko |first3=S. S. |last4=Petrzhak |first4=K. A. |last5=Shpakov |first5=V. I. |last6=Arl't |first6=R. |last7=Iosh |first7=M. |last8=Muziol |first8=G. |author9=Ortlepp, Kh.-G. |author10=Vagner, V. |display-authors=3|title=Statistical analysis of experimental data on the cross sections of <sup>233, 235, 238</sup>U, <sup>237</sup>Np, <sup>239,242</sup>Pu fission by neutrons of energy 2.6, 8.5, and 14.5 MeV|journal=Soviet Atomic Energy|year=1983|volume=55|issue=4|pages=656–660|doi=10.1007/BF01124127|s2cid=97167743}}</ref> In 1978, Konstantin Petrzhak co-authored a paper (with [[Yuri Oganessian]] and others) about synthesis of [[hassium]] performed in [[Joint Institute for Nuclear Research]].<ref>{{Cite web|url=http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/13/643/13643968.pdf|last2=Тер-Акопьян|first2=Г.М.|language=ru|script-title=ru:Опыты по синтезу 108 элемента в реакции <sup>226</sup>Ra + <sup>48</sup>Ca|trans-title=Experiments on synthesis of 108th element in reaction <sup>226</sup>Ra + <sup>48</sup>Ca|last3=Плеве|first3=А.А.|last4=Чепигин|first4=В.И.|last5=Орлова|first5=О.А.|last6=Зайдель|first6=В.|last7=Селицкий|first7=Ю.А.|last8=Фунштейн|first8=В.Б.|last9=Брухертзайфер|first9=Х. |author10=Константинеску, О. |author11=Шварценберг, М. |author12=Гаврилов, К.А. |author13=Коваленко, С.С. |author14=Петржак, К.А.|last1=Оганесян|first1=Ю.Ц.|author-link1=Yuri Oganessian |display-authors=3}}</ref>
+Petrzhak was awarded [[Doctor of Sciences]] in 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.<ref>{{cite web|url=http://www.ruhep.ru/npd/member.npd/member_e.htm|title=Members of Nuclear Physics Division of Physical Sciences Department of Russian Academy of Sciences|publisher=High Energy and Nuclear Physics in Russia}}</ref> Konstantin Petrzhak published articles on fission products from nuclear reactors<ref>{{cite journal|title=Range of products with A=131–136 in the reactor neutron fission of <sup>237</sup>Np, <sup>243</sup>Am by and thermal neutron fission of <sup>233</sup>U, <sup>235</sup>U, and <sup>239</sup>Pu|journal=Atomic Energy|year=1998|volume=84|issue=4|pages=292–294|last1=Teplykh |first1=V. F. |last2=Platygina |first2=E. V. |last3=Petrzhak |first3=K. A.|doi=10.1007/BF02415238|s2cid=96393999}}</ref> until his death in 1998. He died on October 10, 1998, and was buried at [[Serafimovskoe Cemetery]] in Saint Petersburg.
+== Personal life ==
+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.<ref name="Вечерний Петербург"/> Konstantin Petrzhak married Galina Ivanovna Mitrofanova (b. 1918), also a radiochemist.
+== Awards ==
+* 1946 [[USSR State Prize|Stalin Prize]] (2nd degree; jointly with [[Georgy Flyorov]] for discovery of spontaneous fission; {{Val|100000}} [[Soviet ruble|Soviet rubles]] each;<ref>{{cite news|title=Russian discovery of atomic secrets|url=http://nla.gov.au/nla.news-page686271|newspaper=The Canberra Times|date=January 29, 1946|volume=20|number=5869|page=1}}</ref>)
+* 1950 [[Council of Ministers of the Soviet Union|Council of Ministers]] Prize (for work on fulfillment of governmental tasks)
+* 1953 Stalin Prize (for work on soviet atomic project)
+* 1953 [[Order of the Red Banner of Labour]] (for work on soviet atomic project)
+* 1957 Presidium of Academy of Sciences of the Soviet Union Prize
 == Selected works ==
-* {{cite journal |author=Adamov VM, Drapchinsky LV, Kovalenko SS, Petrzhak KA, Pleskachevsky LA, Tyutyugin II |year=1974 |title=Polar light particle emission in spontaneous fission of <sup>252</sup>Cf |url= |journal=Physics Letters B |publisher= |volume=48 |issue=4 |pages=311-314 |doi=10.1016/0370-2693(74)90597-8 |pmc= }}
+* {{cite journal |vauthors=Flerov GN, Petrzhak KA |title=Spontaneous fission of uranium|journal= [[Physical Review|Phys. Rev.]]|volume= 58|issue=1|pages= 89|date=1 July 1940|doi=10.1103/PhysRev.58.89.2|bibcode=1940PhRv...58...89F}}
+* {{cite book|last1=Dushin|first1=V.N.|last2=Fomichev|first2=A.V.|last3=Kovalenko|first3=S.S.|last4=Petrzhak|first4=K.A. |last5=Shpakov |first5=V.I. |last6=Arlt |first6=R. |last7=Josch |first7=M. |last8=Muziol |first8=G. |last9=Ortlepp |first9=H.G. |author10=Wagner W.|chapter=Statistical analysis of the experimental data of fission cross section measurements on <sup>233, 235, 238</sup>U, <sup>237</sup>Np, <sup>239, 242</sup>Pu at neutron energies of 2.5, 8.4 and 14.5 MeV|title=Proc. of XIIth International symp. on nuclear physics. Gaussig, 1982, ZfK-491|place=Dresden|year=1982|pages=138}}
+* {{cite journal |author=Петржак, К. А. |author2=Флеров, Г. Н.|script-title=ru:Спонтанное деление урана |trans-title=Spontaneous fission of uranium |language=ru |journal=ЖЭТФ| year=1940 |volume=10 |pages=10–13 }}
+* {{cite journal |author=Петржак, К. А. |author2=Флеров, Г. Н.|script-title=ru:Спонтанное деление урана|trans-title=Spontaneous fission of uranium |language=ru |journal=Успехи Физических Наук | year=1941 |volume=25 |issue=2 |pages=241–249|url=http://ufn.ru/ru/articles/1941/2/f/|doi=10.3367/UFNr.0025.194102i.0241}}
-== References ==
+== Notes ==
 <references/>
+==References==
-{{Expand Russian|Петржак, Константин Антонович|date=September 2014}}
+* {{cite book |last= Асташенков |first=Петр Тимофеевич |year=1968 |script-title=ru:Курчатов |trans-title=Kurchatov  |location=М. |publisher=Молодая гвардия |page=24 }}
+* {{cite book |last=Мухин |first=К.Н. |year=1974 |script-title=ru:Экспериментальная ядерная физика|trans-title=Experimental nuclear physics |language=ru |volume=1 |location=М. |publisher=Атомиздат |pages=477}}
+* {{cite book |author=Горбачев, В. М. |author2=Замятнин, Ю. С. |author3=Лбов, А. А.|script-title=ru:Взаимодействие излучений с ядрами тяжелых элементов и деление ядер. Справочник.|trans-title=Interaction of radiation with nuclei of heavy elements and nuclear fission. Reference |language=ru |location=М. |publisher=Атомиздат |year=1976}}
+* {{cite book |year=2000 |editor1-last=Рябев |editor1-first=Л. Д. |script-title=ru:Атомный проект СССР. Том II. 1945-1954 Книга 2 |trans-title=Soviet atomic project.|language=ru |volume=II |location=Москва-Саров |publisher=РФЯЦ-ВНИИЭФ |isbn=5-85165-402-3 |ref={{harvid|РФЯЦ-ВНИИЭФ|2000}}}}
+{{Soviet Atomic Bomb Project}}
+{{authority control}}
-{{Persondata
-| NAME              = Petrzhak, Konstantin
-| ALTERNATIVE NAMES =
-| SHORT DESCRIPTION = Soviet nuclear physicist
-| DATE OF BIRTH     = 1907
-| PLACE OF BIRTH    =
-| DATE OF DEATH     = 1998
-| PLACE OF DEATH    =
-}}
 {{DEFAULTSORT:Petrzhak, Konstantin}}
-[[Category:People from Łuków County]]
 [[Category:1907 births]]
-[[Category:Soviet nuclear physicists]]
+[[Category:1998 deaths]]
-[[Category:Stalin Prize winners]]
+[[Category:People from Łuków]]
+[[Category:People from Siedlce Governorate]]
+[[Category:Academic staff of the Saint Petersburg State Institute of Technology]]
+[[Category:Saint Petersburg State University alumni]]
 [[Category:Recipients of the Order of the Badge of Honour]]
 [[Category:Recipients of the Order of the Red Banner of Labour]]
-[[Category:Recipients of the Order of the Patriotic War, 2nd class]]
+[[Category:Recipients of the Stalin Prize]]
-[[Category:Saint Petersburg State University alumni]]
+[[Category:Nuclear weapons program of the Soviet Union people]]
-[[Category:1998 deaths]]
+[[Category:Soviet Army officers]]
+[[Category:Soviet military personnel of World War II]]
+[[Category:Soviet nuclear physicists]]
+[[Category:Soviet people of Polish descent]]
-{{Russia-physicist-stub}}
+[[Category:Burials at Serafimovskoe Cemetery]]