More 'beam time' needed to map cadmium

NSW DPI scientist Paul Milham is planning a return for more valuable ‘beam time’ at the Advanced Photon Source (APS) near Chicago in his bid to develop a method for mapping the micro-scale concentration of cadmium in soils.

"The distribution of cadmium in soils is poorly understood and the particles are so small there is no current means of mapping them in soils," said Mr Milham, who is based at Richmond.

"Testing requires measurements using a powerful beam of x-rays from a synchrotron, which is not accessible in Australia.

"Electrons circulate in the synchroton’s one kilometre ‘ring’ - housed in a doughnut shaped building at Argonne near Chicago - faster than 99.9 per cent the speed of light."

Synchrotron time at the APS is scarce and Mr Milham’s 72 hour allocation last year was highly informative but inconclusive.

With assistance of another grant from the Australian Synchrotron Research Program Mr Milham plans a return trip and is confident of getting results.

"We are heading back to have another go with the synchrotron cranked up to the maximum level," he said.

"The physicist and engineer at Argonne near Chicago say they will be able to increase the sensitivity on the synchrotron by about 10-times.

"We have also learnt more about how to prepare and present the soil sample to the instrument.

"We aim to develop a three-dimensional map of cadmium in soils which will be invaluable for our understanding of the complex behaviour of this element."