ANZAAS Victoria held a boffo symposium earlier this month--four hours of talks about the plans for the Australian synchrotron, a national facility to be constructed in Melbourne's eastern suburbs.
[Please note: I'm not a physicist! If you want detailed information about how the beastie works, visit the URL just above my signature thingo, or ask some of the more knowledgeable people on the list like Chris Lawson, Peter Macinnis, David Martin, Mike Mealy, Zero Sum et al. Any errors in the notes below are mine, not those of the people who spoke at the symposium.]
The synchrotron has been a long time coming. The idea was first raised in 1993-94, amid awareness that we were rapidly becoming a synchrotronic minority among OECD countries: it's just us, Mexico and Turkey who don't have synchrotrons; every other OECD country has built one. Currently, most Australian synchrotron work is sent to the US or Singapore--expensive and time-consuming for the researchers.
A synchrotron is a machine that speeds up electrons, then diverts them (in a circle) so that a stream of photons shoots off at a tangent. The photon beams are characterised by sharp pulses, separated by long periods, with a high degree of polarisation. (Look up photon beam experiments if you want to know more about this stuff.)
I've seen photos of synchrotron beams that look something like a coloured laser beam, but the synchrotron beam can be much more accurately 'tuned' to a particular wavelength than a laser beam. As well, the synchrotron can be set to emit a single frequency pretty much anywhere in the spectrum from x-rays to ultraviolet.
Earlier today, David Martin mentioned the 'candle' as a measure of brightness in stars. Here's a little comparison to give some perspective to the synchrotron's output:
Brightness = the number of photons per second per mm squared.
1 candle = 10 to the 9th photons per second per mm squared
Medical x-ray = 0.01 candle
Sunlight = 10,000 candles
Synchrotron = 10,000,000,000 candles
And yet the Australian synchrotron will require only about 5 megawatts of electricity to run. Golly.
The synchroton promises all kinds of wonderful usefulness: treating cancers, improved x-rays for medical diagnosis, making micromachines, x-ray microscopy of crystals for improved manufacturing purposes, detailed scanning of molecular structures for improved drug development...
Each of these applications requires a different output frequency, but 'tuning' the synchroton is not a matter of twiddling a dial. Instead it has fixed 'windows' that emit beams at pre-set wavelengths. At the moment, the national expert committee is deciding which eight of all the possible frequencies will get priority when the synchrotron first becomes operational in 2007 (more can be added later, up to about 30).
More about the Australian synchrotron here: http://www.synchrotron.vic.gov.au/about_us/
Next week I'll type up some more notes
from the symposium, outlining some of the possible applications for the
beastie. Tune in again, same bat-time, same bat-channel...
