Speaker
Dr
Stefaan Pommé
(EC-JRC-IRMM, Belgium)
Description
213Bi is one of the most important &alpha-emitting nuclides used in targeted alpha therapy (TAT) against cancer. It is readily available from the subsequent &alpha-decay of 225Ac → 221Fr → 217At → 213Bi. The parent half-life is T1/2(225Ac)=9.920 (3) d (Pommé et al., in press), while 221Fr and 217At are shorter-lived. 213Bi has a half-life of about 45.6 min and decays to the longest-lived alpha emitter 209Bi through two branches, each involving one &alpha-decay and two &beta-decays. An IAEA Coordinated Research Project has identified the need for a new half-life measurement of 213Bi.
In this work, 213Bi has been separated from an open 225Ac source by collecting recoil atoms onto a glass plate in vacuum. The activity of such recoil sources has been followed as a function of time, using an ion-implanted planar Si detector in quasi-2&pigreco geometry, resulting in a new half-life value. Additional high-resolution alpha-spectrometry measurements were performed at a solid angle of 0.4% of 4π sr, to verify the energies and emission probabilities of the &alpha-emissions from the decay products of 225Ac. For both experiments, a description of the measurement method and data analysis is provided. The resulting decay data are given with an uncertainty budget and compared with literature values.
Primary author
Dr
Maria Marouli
(EC-JRC-IRMM, Belgium)
Co-authors
Dr
Gabriel Suliman
(EC-JRC-IRMM)
Dr
Stefaan Pommé
(EC-JRC-IRMM, Belgium)