It's fair to say very few people would still be going to work, and for free, more than 14 years after they retired. The number who have gained a Ph D after officially ending their work career and are now working on a post-doctoral thesiswould be minute, indeed.
But Dr Hugh Wyllie has a passion for his work in what might appear the highly esoteric world of calculating the rates of decay of radioactive substances. He's not sure whether he is caught by boundless scientific curiousity or an obsessive hobby, but most days find him travelling from his Cronulla home to work in an immaculate laboratory at ANSTO at Lucas Heights.
A bank of sensors connected to computers using programs written by Dr Wyllie count each burst of energy released as radioisotopes such as cobalt-60 decay. It's more than five decades since Hugh Wyllie collected his masters degree in chemistry from the University of Queensland.
He worked for the then ICI in its explosives and plastics divisions before joining ANSTO's predecessor, the Australian Atomic Energy Commission, in 1968. He was chemist in charge of radioactive sources produced for the CSIRO, industry and universities.
Because it is essential to minimise radiation exposure to patients receiving medical isotopes or in processes using industrial isotopes, precise knowledge of- the amount of radioactivity they emit is needed. The painstaking counting and analysis- of radioactive decay of such isotopes at Dr Wyllie's lab, cross-referenced against similar research overseas, means Australia's standards in the field are set at Lucas Heights.
While Dr Wyllie says accuracy was about 50 per cent when he joined the AAEC and is now about a tenth of one per cent for the widely used medical isotope cobalt-60, even more accuracy is required.
The problem he is now researching is called coincidence counting. When two types of radioactive particles, such as gamma and beta, decay at the same time, sensors can currently count only one. This means the amount of energy to which a patient getting a medical radioisotope is exposed can be underestimated.
How to make better calculations and provide more precise information for using radioactive substances in medicine and industry will be the subject of Dr Wyllie's postdoctoral thesis. It follows the impressively named, "Correction Equations for Radioactivity Measurements by Coincidence Counting," for which he was awarded his PhD at Macquarie University in 1997.
He doesn't watch television, listens to a fair bit of radio and keeps a notebook beside his bed to record those deep in the night inspirations. There isn't much spare time, although walking has taken over from previous pursuits of surfing and flying.
Then there's a couple more areas of research that interest him. First the thesis, now the post-doctoral thesis and its sequel ... "a bit like Terminator 3," Dr Wyllie mused.