Resonant laser ionization and mass separation of 225Ac

225 Ac is a radio-isotope that can be linked to biological vector molecules to treat certain distributed cancers using targeted alpha therapy. However, developing 225Ac-labelled radiopharmaceuticals remains a challenge due to the supply shortage of pure 225 Ac itself. Several techniques to obtain pure 225 Ac are being investigated, amongst which is the high-energy proton spallation of thorium or uranium combined with resonant laser ionization and mass separation. As a proof-of-principle, we perform off-line resonant ionization mass spectrometry on two samples of 225Ac, each with a known activity, in different chemical environments. We report overall operational collection efficiencies of 10.1(2)% and 9.9(8)% for the cases in which the 225 Ac was deposited on a rhenium surface and a ThO2 mimic target matrix respectively. The bottleneck of the technique was the laser ionization efficiency, which was deduced to be 15.1(6)%.

JOHNSON Jake David;  HEINES Michael;  BRUCHERTSEIFER Frank;  CHEVALLAY Eric;  COCOLIOS Thomas Elias;  DOCKX K.;  DUCHEMIN Charlotte;  HEINITZ Stephan;  HEINKE Reinhard;  HURIER Sophie;  LAMBERT Laura;  LEENDERS Benji;  SKLIAROVA Hanna;  STORA Thierry;  WOJTACZKA Wiktoria; 

2023-07-13

NATURE PORTFOLIO

JRC134375

2045-2322 (online),   

https://www.nature.com/articles/s41598-023-28299-4,    https://publications.jrc.ec.europa.eu/repository/handle/JRC134375,   

10.1038/s41598-023-28299-4 (online),