Josef von Schintlmeister (16 June 1908, Radstadt – 14 August 1971, Hinterglemm) was an Austrian nuclear physicist and an amateur alpinist.

This work was done under the German nuclear energy project, also known as the Uranverein (Uranium Club); see, for example, the publications cited below under Internal Reports.

[2][3][4] In work completed in June 1940 and published in 1941, Schintlmeister had followed a line of reasoning similar to that of Carl Friedrich von Weizsäcker and Fritz Houtermans and had predicted the existence of the 94th element, plutonium.

In two papers published in May 1941, Schintlmeister spelled out the implications of the 94th element in that it could be generated in a Uranmaschine (uranium machine, i.e., a nuclear reactor) and that it would be fissionable.

The main search team, headed by Colonel General Zavenyagin, arrived in Berlin on 3 May, the day after Russia announced the fall of Berlin to their military forces; it included Colonel General V. A. Makhnjov, and nuclear physicists Yulij Borisovich Khariton, Isaak Konstantinovich Kikoin, and Lev Andreevich Artsimovich.

[18][19][20] On Schintlmeister's return to Vienna, he was invited to the British embassy, where a Scientific and Technical Intelligence Branch (STIB)[21] officer asked him about his time in the Soviet Union.

Once, visiting Austria after he had taken the positions in Dresden, British officials offered him the choice of either defecting or becoming a source in the Bloc, preferably the Soviet Union.