New Forensic Insight into Carl Auer von Welsbach's 1910 Observation of Induced Radioactivity: Theoretical, Experimental and Historical Approaches

Download statistics - Document (COUNTER):

Steinhauser, G.; Adunka, R.; Hainz, D.; Löffler, G.; Musilek, A.: New Forensic Insight into Carl Auer von Welsbach's 1910 Observation of Induced Radioactivity: Theoretical, Experimental and Historical Approaches. In: Interdisciplinary Science Reviews 41 (2016), Nr. 4, S. 297-318. DOI:

Repository version

To cite the version in the repository, please use this identifier:

Selected time period:


Sum total of downloads: 101

In 1910, Carl Auer von Welsbach noted that he had made an observation of a radioactive substance inducing radioactivity to an inactive substance. From today's point of view, this could have been the first observation of neutron activation. Herein, we present new insights into our investigation of this ‘mysterious observation’ as Auer von Welsbach termed it. We believe that one of the activated objects was a platinum–iridium crucible. The dominating activation product of the crucible could have been iridium-194. We have discovered several platinum crucibles from Auer's heritage and investigated them by gamma-spectrometry and, one of them, by SEM/EDX. In the EDX investigations, however, no iridium was found in the most promising crucible. Hence this particular crucible was probably not the activated object. In any case, gamma-ray spectrometry revealed very low but detectable amounts of natural radionuclides. This indicated that these crucibles were used by Auer von Welsbach for his radioactive work and that these crucibles were bought prior to World War I. Hence Auer von Welsbach somehow managed to save these crucibles from the noble metal collections during the war. Auer's 1910 publication carried the suffix ‘Part I’, however, Part II was thought to be lost. In our recent work, however, we rediscovered a hand-written manuscript of Part II, in which the peculiar observation is mentioned vaguely. Lastly, we converted Auer's uranium standard into becquerels. Based on this conversion, we estimated that Auer von Welsbach observed an 194Ir activity of the crucible of 500 kBq. It is further estimated that a (thermal) neutron flux density of approximately 8E+4 cm−2 s−1 was needed to activate the crucible in a way to meet Auer's description. This is an Accepted Manuscript of an article published by Taylor & Francis in Interdisciplinary Science Reviews on 2017-01-09, available online:
License of this version: Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden.
Document Type: Text
Publishing status: acceptedVersion
Issue Date: 2016
Appears in Collections:Fakultät für Mathematik und Physik

distribution of downloads over the selected time period:

downloads by country:

pos. country downloads
total perc.
1 image of flag of Germany Germany 85 84.16%
2 image of flag of Austria Austria 5 4.95%
3 image of flag of France France 3 2.97%
4 image of flag of United States United States 2 1.98%
5 image of flag of Japan Japan 2 1.98%
6 image of flag of Ukraine Ukraine 1 0.99%
7 image of flag of Tanzania, United Republic of Tanzania, United Republic of 1 0.99%
8 image of flag of Netherlands Netherlands 1 0.99%
9 image of flag of United Kingdom United Kingdom 1 0.99%

Further download figures and rankings:


Zur Erhebung der Downloadstatistiken kommen entsprechend dem „COUNTER Code of Practice for e-Resources“ international anerkannte Regeln und Normen zur Anwendung. COUNTER ist eine internationale Non-Profit-Organisation, in der Bibliotheksverbände, Datenbankanbieter und Verlage gemeinsam an Standards zur Erhebung, Speicherung und Verarbeitung von Nutzungsdaten elektronischer Ressourcen arbeiten, welche so Objektivität und Vergleichbarkeit gewährleisten sollen. Es werden hierbei ausschließlich Zugriffe auf die entsprechenden Volltexte ausgewertet, keine Aufrufe der Website an sich.

Search the repository