ABSTRACT
Microdosimetry as an experimental branch of radiation science arose more than half a century ago from efforts to measure the quantity Linear Energy Transfer (LET). At that time, LET was becoming recognised as the best way to characterise and quantify ‘ionisation density’ or ‘radiation quality’ as well as a means by which to understand the physical basis of why one radiation type may be different from another in its biological impact. Harald Rossi, considered the founding father of microdosimetry, along with other pioneers in the field, quickly realised that the experimental methods they were developing provided a distinctive insight into the stochastic nature of radiation interaction as well as a unique signature of radiation quantity. Albrecht Kellerer, a principal figure in formulating the theoretical foundations of microdosimetry and a longtime collaborator of Rossi’s, has given an insightful overview of the origins and evolution of microdosimetry in the first Rossi Lecture delivered at the 13th Symposium on Microdosimetry (Kellerer, 2002).
