A Reconsideration of Ştefania Mărăcineanu’s Measurements of Polonium-210’s Half-Life: Understanding Her Claim to the Discovery of Artificial Radioactivity

• Published in: Physics in perspective Vol. 22; no. 3; pp. 162 - 181
• Main Author: Bucurescu, Dorel
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.09.2020; Springer Nature B.V
• Subjects: Half-life; Least squares method; Physics; Physics and Astronomy; Polonium; Radioactivity; Radium; 210-polonium half-life; Institut du Radium; history of nuclear physics; Ştefania Mărăcineanu; Marie Curie; artificial radioactivity
• ISSN: 1422-6944; 1422-6960
• DOI: 10.1007/s00016-020-00259-9

I re-examine the raw data of the measurements of the half-life of 210 Po from the Romanian physicist Ştefania Mărăcineanu’s doctoral thesis, performed at the Institut du Radium, 1921–1923, under the supervision of Marie Curie. The half-life values reported in the thesis show relatively large divergences and a possible dependence on the (metallic) support on which the Po source was deposited. These findings influenced Mărăcineanu’s subsequent independent research, and later compelled her to claim priority for the discovery of artificial radioactivity. The present analysis of these data, performed with the least-squares method, certifies the outstanding accuracy of the experimental measurements by providing values with good agreement between the different series of measurements and an average value that is close to the currently adopted half-life value of this isotope. On the other hand, this analysis changes our perspective by showing that the rudimentary procedure Mărăcineanu used to processing the data introduced errors in her reported values, which favored a poor interpretation of the results.