Konstantin Petrzhak

For other people named Pietrzak, see Pietrzak (disambiguation).

Konstantin Petrzhak
Константин Антонович Петржак
Born	(1907-09-07)September 7, 1907 Łuków, Congress Poland, Russian Empire (now Łuków, Poland)
Died	October 10, 1998(1998-10-10) (aged 91) Russia
Nationality	Pole
Alma mater	Saint Petersburg State University
Known for	Discovery of spontaneous fission
Awards
Scientific career
Fields	Physics (nuclear)
Institutions	Khlopin Radium Institute Saint Petersburg State Institute of Technology
Doctoral advisor	Igor Kurchatov
Other academic advisors	Vitaly Khlopin

Konstantin Petrzhak (Russian: Константи́н Анто́нович Петржак, IPA: [kənstɐnʲˈtʲin ɐnˈtonɐvɪt͡ɕ pʲɛtʐak]; 1907-1998) was a Soviet physicist of Polish origin. He discovered spontaneous fission of uranium jointly with Georgy Flyorov in 1940.

Biography

Konstantin Petrzhak was born on 3 September 1907 in Łuków (Congress Poland, Russian Empire, now in Poland). Antoni Petrzhak was his father. In 1936 Konstantin Petrzhak graduated from Saint Petersburg State University. Later he started working at Khlopin Radium Institute in Saint Petersburg (which was named First Radium Institute at that time). Igor Kurchatov was the head of laboratory where he started working. There Konstantin Petrzhak wrote his thesis. 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 station of Moscow Metro. They constructed a highly sensitive ionization chamber to detect uranium debris. The ionization chamber had electrodes in it with the total square of about 1000 cm². The samples of uranium were placed inside the chamber. The detector was checked while measuring background. When the source of neutrons was taken away the detector still detected particles. Then they assumed that spontaneous fission was discovered. 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".

In 1940 Konstantin Petrzhak was suggested to enter the leading team of soviet atomic bomb project. He is rumoured to participate in soviet atomic project.

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.

Konstantin Petrzhak founded a laboratory of neutron physics and nuclear fission in Khlopin Radium Institute in 1947 and was the head of this laboratory until 1986. Later he was one of the founders of Engineering faculty of Saint Petersburg State Institute of Technology. There he founded a department of nuclear physics in 1949 and was the head of it for 22 years. 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. He was awarded 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.

Selected works

• 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. doi:10.1016/0370-2693(74)90597-8.{{cite journal}}: CS1 maint: multiple names: authors list (link)