Jean Danysz (11 March 1884 – 4 November 1914) born Jan Kazimierz Danysz, was a French physicist of

Polish Polish may refer to: * Anything from or related to Poland, a country in Europe * Polish language * Poles Poles,, ; singular masculine: ''Polak'', singular feminine: ''Polka'' or Polish people, are a West Slavic nation and ethnic group, w ...

extraction. He was an assistant of

Maria Skłodowska-Curie Marie Salomea Skłodowska–Curie ( , , ; born Maria Salomea Skłodowska, ; 7 November 1867 – 4 July 1934) was a Polish and naturalized-French physicist and chemist who conducted pioneering research on radioactivity. She was the first ...

and notable in the development of beta spectrometry. Danysz made considerable advances on the

magnetic deflection In physics, deflection is a change in a moving object's velocity, hence its trajectory, as a consequence of contact (collision) with a surface or the influence of a non-contact force field. Examples of the former include a ball bouncing off the ...

techniques of Baeyer, Hahn and Meitner, placing the source (he used radium) in a capillary tube under a slit, with a photographic plate in the same horizontal plane. By this means the known number of lines (later understood to be conversion lines) superimposed on the beta energy spectrum of RaB + RaC went from 9 to 27 (later work by

Robinson Robinson may refer to: People and names * Robinson (name) Fictional characters * Robinson Crusoe, the main character, and title of a novel by Daniel Defoe, published in 1719 Geography * Robinson projection, a map projection used since the 1960 ...

and Rutherford found 64; 16 from RaB and 48 from RaC). He finished his doctoral thesis in 1913, and by 1914 he was considered by Rutherford as a leading researcher into

beta decay In nuclear physics, beta decay (β-decay) is a type of radioactive decay in which a beta particle (fast energetic electron or positron) is emitted from an atomic nucleus, transforming the original nuclide to an isobar of that nuclide. For ...

, but he did no further work. He enlisted in the French army in 1914 and was killed in action near Cormicy.

Publications

J. Danysz, Le Radium 9, 1 (1912); 10, 4 (1913) Danysz, J. ''Recherches expérimentales sur les β rayons de la famille du radium'' Ann. Chim. Phys. 30 (1913) 241–320

Family

* He was the son of biologist Jean Danysz (1860-1928).''Bulletin littéraire et scientifique'' (Association des anciens élèves de l'Ecole polonaise) - 1914/12/15 (Année 39, N°316) * He was the father of physicist Marian Danysz (1909–1983).

References

1884 births 1914 deaths 20th-century French physicists French Army soldiers French military personnel killed in World War I {{Physicist-stub