, Mrs. Geiger,
Lise Meitner,
Otto Hahn. Seated, l. to r.:
James Chadwick,
Hans Geiger,
Ernest Rutherford,
Stefan Meyer, Karl Przibram, International Bunsentagung on Radioactivity in Münster (16–19 May 1932) As early as 1926, Meyer had written to
Irène Joliot-Curie suggesting that Rona work with her to learn how his laboratory could make their own polonium samples. Once
Hans Pettersson was able to secure funds to pay Rona's expenses, Joliot-Curie allowed her to come and study polonium separation at the
Curie Institute in Paris. Rona developed an enhanced method of preparing polonium sources and producing alpha-emissions.(
α-emission). Gaining recognition as an expert in the field, she took those skills back to the Radium Institute along with a small disc of polonium. This disc allowed her to create lab specimens of polonium, which were used in much of the Institute's subsequent research. Her skills were in high demand and she formed many collaborations in Vienna, working with
Ewald Schmidt on the modification of
Paul Bonét-Maury's method of vaporizing polonium; with
Marietta Blau on photographic emulsions of hydrogen rays; and with Hans Pettersson. In 1928, Pettersson asked her to analyze a sample of sea bottom sediment to determine its radium content. Because the lab she was working in was contaminated, she took the samples to the oceanographic laboratory at
Bornö Marine Research Station on
Stora Bornö in
Gullmarsfjorden, Sweden, which would become her summer research destination for the next 12 years. Her analyses with
Berta Karlik on the half-lives of
uranium,
thorium, and
actinium decay identified
radiometric dating and elemental
alpha particle ranges. In 1933, Rona and Karlik won the
Austrian Academy of Sciences Haitinger Prize. In 1934, Rona was back in Paris studying with Joliot-Curie, who had discovered
artificial radioactivity. Soon after, Curie died and Rona became ill, but she was able to return to Vienna late the following year to share what had been learned with a group of researchers made up of Pettersson,
Elizabeth Kara-Michailova, and
Ernst Føyn, who was serving as an assistant to
Ellen Gleditsch at that time. Their studies centered on research of the effect caused by bombarding radionuclides with neutrons. In 1935 Rona consolidated some of these relationships, working on Stora Bornö, then visiting Gleditsch in
Oslo, then traveling to
Copenhagen to see Hevesy, and later to
Kålhuvudet, Sweden to meet with Karlik and Pettersson. One of the projects the group had been working on for several years was to determine if there was any correlation between water depth and radium content, and their seawater research evaluated the concentration of elements in seawater collected from different locations. After the 1938
Anschluss, Rona and Marietta Blau left the Radium Institute because of their Jewish heritage and the antisemitic persecution they experienced in the laboratory. Rona first returned to Budapest and worked in an industrial laboratory, but within a few months, the position was eliminated. She worked from October to December 1938 in Sweden, and then accepted a temporary position for one year at the
University of Oslo, which had been offered by Gleditsch. Reluctant to leave her home, at the end of her year in Oslo, Rona returned to Hungary. She was appointed to a position at the Radium-Cancer Hospital in Budapest, preparing radium for medicinal purposes. ==Emigration==