Sorry, I’m not actually here to talk about doughnuts with sugar and icing. I’m here to talk about the giant, spaceship-looking kind that can produce light 10 billion times brighter than the Sun, aka the synchrotron light source .
Up to 1.5 km in circumference, a synchrotron ring is a type of particle accelerator. Negatively charged particles, or electrons, are travelling so fast they could travel around the entire globe seven and a half times a second , and guided around the ring by a number of huge magnets. Each time this speedy electron beam hits a magnet and subsequently steered back on track, it loses energy.
The experimental hall and storage ring building of the ESRF. (Courtesy: P.Ginter/ESRF)
Ever heard the old adage, “One man’s trash is another man’s treasure”?
Well, in this instance the first man is the electron and the other man is us, the scientists, who bottle up that lost energy and use it for our experiments.
This energy loss is better than it sounds. It’s a beam of light that is so powerful it has a brilliance of up to 1020 photons per second per millimetre squared per milliradian squared per 0.1% of the bandwidth!
That means nothing to me either . Apparently, it means it’s really bright and up to 10,000,000,000,000 times brighter than a hospital x-ray source. In addition to its incomprehensible brilliance, this radiation has a wide fan of wavelengths either side of visible light; from infrared to hard x-rays. In other words, we have a tool that can study activity at a sub-atomic level that couldn’t be done with the naked eye or even electron microscopes. By tuning the wavelength of this beam, made possible by various optics and monochromators that focus light into different wavelengths , we can pick what kind of “molecular microscope” we need. Ultraviolet light, soft x-rays and hard x-rays have wavelengths much shorter than those of visible light, and so these are useful to look at atomic structures and chemical reactions in minute detail. Infrared radiation, longer wavelength than visible light, can be used to probe the atomic vibrations within our samples. .h3> Then what?
There is some amazing research going on at synchrotrons encompassing a huge spectrum of topics. Molecular information about new pharmaceuticals is being discovered nearly every day, including the anti-flu drug Tamiflu, whose atomic structure was determined using synchrotron radiation . At the synchrotron in Brookhaven, USA, researchers have molecularly mapped the entire components of human hair . If that isn’t good enough, researchers at the Rutherford Appleton Lab in collaboration with Oxford University take actual live spiders to a synchrotron and probe their silk in-situ to unravel the secrets of the strongest polymer known on Earth . Sounds like we could be travelling in aeroplanes made out of spider webs pretty soon, which I’m not sure yet is really cool or really freaky.
Not really. At least not without a significant amount of funding, a successful application and, often the limiting factor, passing an online safety test. However, if you are lucky enough to have the opportunity to work at a synchrotron facility, be grateful but also prepared. The facilities are usually 24 hours, so round-the-clock data collection is not uncommon. You may find yourself working during hours you didn’t know existed, and not being sure of the day, date or year . Having said that, if you can put up with being delirious for five days, it can be worth it for being both at the beginning and the forefront of science. You may want to bring actual doughnuts.