Among the hatches, twisted pipes and over six kilometres of aluminum foil that lies within the synchrotron at the U of S, researchers are harnessing the power of light to make highly detailed images of everything from live animals to diseases.
The bulk of the Canadian Light Source is essentially an electron holding tank. Fired from an electron gun housed next door to the facility, highly charged electrons are kept circulating within the inner chamber, attaining speeds close to that of light. The electrons are kept circulating with the use of powerful electromagnets.
When the electrons change directions, they emit photons, tiny particles of light. Researchers use the light radiated from the electrons to take images of samples — shining different spectrums of light rays at them and watching the reaction.
The synchrotron runs 24 hours a day for researchers, with some waiting up to six months to get a spot on a beamline. Running those powerful magnets takes up a hefty amount of energy, with the CLS consuming as much as 10 per cent of the city’s electricity. A small price to pay, some would say, for the revolutionary imaging techniques provided by the facility.
“The hallmark of the beamline is being able to look at things without having to take them apart,” said David Chapman, who works on the biomedical imaging and therapy beamline.
Unlike conventional X-rays, the radiation from the synchrotron can even be employed to get detailed images of softer tissues, like tumors.
“We can develop contrasts you can’t get from normal X-rays,” said Chapman. He and his team have been doing studies with applications for veterinary medicine.
“The beamline itself is, I’d guess I’d use the term ”˜coming alive,’ ” he said. “We’ve imaged live chickens. Eventually we’ll be able to image things as big as a horse or a cow.”
Chapman is doing research on the bone development of broiler chickens.
“Those chickens grow very, very fast. Roughly in about 30 days from being hatched they’re made into food.” This leads to stress on their bones and, sometimes, broken limbs.
“They grow so fast that there’s some pathology with the bones that isn’t understood at all. A few per cent of those chickens are crippled by that,” said Chapman.
He said it’s not just an economic issue but also one of animal welfare.
Similarly, Chapman has teamed up with a Calgary researcher to do images of the hooves of horses that have gone lame.
“Understanding what goes on in the hoof in this disease is something we’re hoping we can look at. Again, it’s an animal welfare issue”¦ Occasionally they’ll shoot animals because they can’t walk,” he said.
Chapman uses a technology called defraction enhanced imaging, which allows him to get much more detailed pictures than typical X-rays can provide.
“It’s very good at finding the edges of things,” he said. This has applications for breast cancer, allowing doctors to accurately pinpoint how far the cancer has spread.
“In something like breast cancer, one of the things that’s very hard is finding what’s called the margins of the cancer.”
So far, the CLS is not used to study live human beings, but it’s just a matter of time, says Chapman. There are many safeguards that must be met before studies can begin on people. “We have to look carefully at how that is done and make sure that’s done safey,” Chapman said.
Putting a human in the beamline exposes them to radiation but the dose of radiation is likely lower than that from a conventional X-ray, though there is some potential for high doses in some of the beamlines.
“Even though you can walk into a clinic and get a dose that’s probably higher, we have to make sure it’s done right the first time. I’ve been imaged, so it’s not fatal— at least not yet,” said Chapman, laughing.
The CLS does not just provide opportunities for post-graduate researchers. Some undergraduates are getting in on the action too.
Agriculture and bio-resources engineering student Stephan Kopchynski landed a summer job at the CLS in the machine shop.
“Machine design is kind of my specialty relative to everybody else. I’m not really a computer guy,” he said.
Kopchynski works at the synchrotron part time along with his classes, doing drawings for the biomedical beamline. “They want the beamline drawn in a 3-D model,” he explained.
Kopchynski landed the job after one of his professors gave him a tip that they were looking for people. Now he’s been offered to join the project as a master’s student when he completes his degree. He says he is still on the fence about it though.
Working with a team of professional researchers has been a little intimidating.
“You’re in over your head on some level but you have to start somewhere. And they understand that too. They don’t expect an undergrad to know everything about the synchrotron.”
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photo: Robby Davis