Science Headlines - Synchrotrons: splitting hairs
An information service for media in New Zealand
Australian researchers recently used a United States synchrotron to identify arsenic in a hair belonging to the famous and long-dead racehorse Phar Lap.
Synchrotrons are a highly useful investigative tool for a number of areas of science from archaeology to medical research, and forensic science to advanced materials research. New Zealand researchers will soon have access to the Australian Synchrotron, a football field sized facility that is expected to come online early next year.
1. Professor Geoff Jameson, a structural biologist and Director of the Centre for Structural Biology at Massey University
"The scientists who analysed Phar Lap's hair would have used a technique called x-ray absorption spectroscopy. Each element absorbs high energy light in a specific way, so it would have been quite easy to tell that there was arsenic in Phar Lap's hair. Careful analysis showed that arsenic was present in two distinct chemical forms indicating that arsenic was administered to Phar Lap. Synchrotrons have also been used to detect art forgery and to examine samples of Beethoven’s hair for symptoms of lead poisoning.
"The Australian synchrotron - due to start operating next year - will be one of about a dozen third-generation synchrotrons in the world. A synchrotron provides a very intense, and tunable, source of light. The Australian synchrotron will accelerate electrons around a 76m diameter ring bending their path with New Zealand-made magnets and accelerating them to around 99.995% of the speed of light.
"New Zealand has put A$5million into the beamline funding pool - the total cost of the whole facility is expected to be around A$220million. We're also putting in about A$5million over six years for running costs. So for a relatively small investment, we’re getting ready access to state-of-the-art facilities that are core to science, medicine and technology today."
2. Professor Jim Metson, a materials scientist at The University of Auckland
“The Australian Synchrotron means number one that we will get far greater access to synchrotrons. Research on the structure of proteins already makes use of synchrotrons, and New Zealand scientists in this area will be able to screen a larger number of crystals more easily. In my area of materials science better access to synchrotrons will open up a whole new field.
“One application has been in the material which is used in blue light emitting diodes - made from gallium nitride - which are likely to form the basis of the next generation of electronic devices. Because blue light is shorter in wavelength than red, the next generation of DVDs will use blue laser light. The shorter wavelength means you have higher information density and you can fit much more on a disc."
“I’ve been working with a group in Wellington on different ways of making gallium nitride, and using a synchrotron has basically told us what is possible and what is not.”
3. Professor Sally Brooker, a synthetic chemist and X-ray crystallographer at the University of Otago
“One of my interests is in something called spin crossover - where molecules switch between two states depending on temperature, pressure or irradiation by light. This switching can be considered akin to a binary code, zero or one, so ultimately these sorts of molecules could form the switches in molecular (tiny yet powerful!) computers. We try to relate the detailed 3D structure of the molecules in these crystals to how they behave, such as at what temperature the molecule switches states. Once you know that relationship you can fine-tune the design of the molecule to improve its behaviour.
“But when we make really small crystals - unfortunately sometimes we simply can’t grow bigger crystals! - we can’t study them using conventional light sources like the X -rays we have access to in NZ. They’re just too weak. For really tiny crystals the intense synchrotron X- rays are perfect and allow us to determine the 3D structure of new materials which we couldn’t otherwise do. We’ve sent a few such tiny crystals to synchrotrons overseas but most of them haven’t survived the trip. The Australian synchrotron - as well as Melbourne being cheap and easy for us to get to - is at a university, so we should be able to use the chemistry department facilities there to grow the crystals we want tested at the synchrotron so they no longer have to survive a long trip.”
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