Jean Danysz (11 March 1884 – 4 November 1914) born Jan Kazimierz Danysz, was a French physicist of Polish extraction. He was an assistant of Maria Skłodowska-Curie and notable in the development of

beta Beta (, ; uppercase , lowercase , or cursive ; or ) is the second letter of the Greek alphabet. In the system of Greek numerals, it has a value of 2. In Ancient Greek, beta represented the voiced bilabial plosive . In Modern Greek, it represe ...

spectrometry. Danysz made considerable advances on the

magnetic deflection 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 ground o ...

techniques of

Baeyer Johann Friedrich Wilhelm Adolf von Baeyer (; 31 October 1835 – 20 August 1917) was a German chemist who synthesised indigo and developed a nomenclature for cyclic compounds (that was subsequently extended and adopted as part of the IUPAC org ...

, 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 19 ...

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 an atomic nucleus emits a beta particle (fast energetic electron or positron), transforming into an isobar of that nuclide. For example, beta decay of a neutron ...

, 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 Jean Danysz (11 March 1884 – 4 November 1914) born Jan Kazimierz Danysz, was a French physicist of Poland, Polish extraction. He was an assistant of Maria Sklodowska-Curie, Maria Skłodowska-Curie and notable in the development of Beta dec ...

(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