Emission of Auger electrons and X-rays can be triggered by creation of vacancies through nuclear decays such as internal conversion of electron capture. Non-energetic Auger electrons are usually neglected in handling of Auger-electron-emitting radioisotopes. Recent experiments show that Auger electrons exhibit high linear energy transfer (LET) behaviour, and are effective in killing targeted cells when emitting radioisotopes are very close to the nuclear DNA (~10 nm). Auger emitters are now of great interest in internal radiotherapy of malignancies. Biological effectiveness of Auger emitters depends on theirs Auger yields per nuclear decay. The databases of Auger yields for medical radioisotopes are highly inconsistent and computed using outdated nuclear and atomic data.
The project is an experimental effort that will be part of a larger research program and aims to verify the theoretical calculations on this topic performed at the ANU by Boon, Kibedi and Stuchbery. It is thus an experimental test of our understanding of the Auger yield per nuclear decay.
This experimental project will involve developing methods for making thin film samples electro-chemically and measuring these samples with a modern spectrometer. First nanometer-thick films will be prepared and characterised by electron spectroscopy from stable atoms, and after this method has been perfected similar films will be grown using radioactive atoms. The Auger electrons leaving the films after nuclear decay will be measured. In this way an experimental estimate of the number of Auger electrons (and their kinetic energy) per nuclear decay will be obtained.