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Synchrotron - why we should get involvedSee also http://www.synchrotron.vic.gov.au/index.asp March 26 2004: Minister Pete Hodgson today welcomed the news that New Zealand company CMS Alphatech has won a $6 million contract to design and supply more than 200 giant magnets for an Australian Synchrotron under construction in Victoria. The Synchrotron project is estimated to cost $206 million and is due for completion in 2007. The magnets for the Australian Synchrotron’s storage ring will be up to 1.7 metres long and weigh up to 7.5 tonnes. They will be used to force electrons into a circular path, creating the intense beams of synchrotron light which can be used to study the composition of matter. CMS Alphatech has been supplying the research and medical physics communities in Australia for more than 15 years. The magnets will be built at Buckley Systems in Auckland, which has been manufacturing electromagnets for particle accelerators since the 1970s. 15 December 2003: "A Light to the Future: The science case for New Zealand investment in the Australian synchrotron" addresses an unparalleled opportunity to invest in New Zealand science and technology, through partnership in a regional science facility of international significance the Australian Synchrotron. Synchrotron science already impacts on a wide spectrum New Zealand R&D no other experimental facility or technique would contribute as broadly, across so many disciplines, and with such scope for further uptake. See /news/synchrotron/case.php Synchrotrons produce very bright light, and are able to shine it on very small things. For instance, they can "see" molecular structures, structures in materials and medical images. Their beams may one day be focused accurately to attack individual cancer cells. To date, Australia has made the major investment for building the ring of the synchrotron, ready for action in 2007. Synchrotron use in countries with such facilities averages some 15% of the science population, and could eventually be even greater in New Zealand, given our science mix. Below is a quick summary of the how, what, and why, of synchrotron radiation compiled by the Royal Society of New Zealand.
1. What is synchrotron radiation?When charged particles such as electrons are forced to move in a circular orbit photons are emitted. If the particles are moving at close to the speed of light, the photons are emitted in a narrow cone in the forward direction and at a tangent to the particles orbit. In a high-energy electron or positron storage ring these photons are emitted with energies ranging from low energy infrared to energetic short wavelength X-rays. This radiation is called Synchrotron Radiation. 2. Advantages of synchrotron radiation2.1. High brightnessThe greatest advantage of the synchrotron radiation is its brightness: synchrotron radiation is extremely intense, hundreds of thousands of times higher than conventional X-ray tubes, and highly collimated (light rays are aligned parallel to one another). You could compare an x-ray beam from a synchrotron with a laser and one from an X-ray tube with a floodlight. While they both might deliver an equal number of photons per second, those from the synchrotron are concentrated in a smaller angle, whereas those from the x-ray tube are widely scattered. A higher flux of photons on a smaller area allows scientists to increase the specificity of their experiments. They can study smaller objects or choose a very specific range of photon energies with which to examine samples. 2.2. Wide energy spectrumSynchrotron radiation is emitted over a wide range of energies, allowing a beam of any energy to be selected. Light used to “see” an object must have a wavelength about the same size as or smaller than the object. Light generated at a synchrotron facility generally covers the range from the far infrared to the hard X-ray region of the electromagnetic spectrum. This range of wavelengths is suited to studying molecules and atoms. 2.3. PolarizationSynchrotron radiation is highly polarized (the electromagnetic radiation is restricted to vibrate in one dimension). This provides a powerful tool with which to study the magnetic properties of materials. 3. How a synchrotron worksCharges particles (electrons) are accelerated to nearly (99.999%) the speed of light. They are forced into almost circular path by sets of magnets, separated by several straight sections. Bright infrared, ultraviolet, and X-ray light emitted by these speeding electrons is directed down beamlines to end stations where researchers perform their experiments. 4. Synchrotron components4.1. The electron gunMuch like a cathode-ray tube in a TV, an electron gun generates electrons from a heated filament that are then directed into a ultra-high-vacuum metal tube. 4.2. LinacA linear accelerator uses microwave energy to increase the kinetic energies of the electrons. When the electrons leave the Linac, they are moving at nearly the speed of light – almost 300 million meters per second. 4.3. Booster ringThe size of a linear accelerator required to obtain the electron energies desired for synchrotron radiation is impractical. Instead, a circular booster ring is used to increase the energy of the electrons. The electrons are bent into a circular path using a series of magnets and accelerated to higher energies using microwave energy. The booster ramps up the electron energy by about a factor of 10. 4.4. Storage ringOnce the electrons reach their target energy in the booster, they are transferred to a long doughnut-shaped vacuum chamber, called the storage ring. Here they are accelerated to their final energy and are then circulated for many hours. In one hour, they travel over one billion kilometers. The electron beam is steered and focused by powerful magnets. As the electrons circle the ring, they shed energy in the form of photons – Synchrotron Radiation. 4.5. Wigglers and undulatorsWigglers and undulators are used in increase the brightness of the synchrotron radiation. A series of magnets of alternating polarity positioned along the straight sections of the storage ring force the electrons into a snaking path. Each bend produces an increase in the intensity of radiation. The overall result is incredibly bright photon beam. The spacing and strength of the magnets can be tuned to enhance specific wavelengths. 4.6. Beamlines / scientific end stationsSynchrotron light is channeled down beamlines, which are used to select specific wavelengths. Finally, when the light reaches the end of the beamline it is directed into individual end stations where the experiments and measurements are conducted. 5. Applications of synchrotron lightSynchrotron light is a versatile and revolutionary tool for researchers in universities and industry who study physical, chemical, geological and biological processes. Among its many applications, synchrotron light is used to:
5.1 Materials researchWorldwide, about 70 percent of all beam time on synchrotrons is used for materials research. Synchrotron light has been used to explore the properties of materials as diverse as semiconductors, glasses, muscle fibers, and plastics. It has played a major role in development of new injection-molded materials such as running shoes, car bodies and bumpers, and furniture foam. The ultra-bright X-rays are being used to help the industry develop solvent-free paints, find new ways to manufacture biodegradable plastics that can be eaten by bugs, and study the surfaces and interfaces between materials; research which can help tackle corrosion problems in cars, planes, and pipelines. 5.2. Medical and biotechnology research:University researchers and a growing number of pharmaceutical and biotechnology companies use synchrotron radiation to determine the three-dimensional structure of proteins. This knowledge can lead to new and better drugs or increase the winter hardiness of wheat. Synchrotron radiation has allowed protein crystal structures to be solved in days verses months or years. Recent preliminary research published in the peer-reviewed journal Nature suggests that synchrotron analysis of a single hair from a woman may reveal whether she has breast cancer. Synchrotron radiation is also used to study the brain and to develop new imaging techniques for medical diagnostics such as non-invasive angiography; X-ray study of the heart and blood vessels to reveal obstructions. It has also been used to study the life cycle of the deadliest malaria parasite in red blood cells. Synchrotron light also has applications in the pharmaceutical, mining, petrochemical, advanced materials, electronics, manufacturing, and transportation industries. Among numerous applications synchrotron radiation is used to:
For more applications see: http://www.sunchrotron.vic.gov.au/about_us/practical.asp 6. The Australian synchrotronThe $206 million Australian Synchrotron Project is expected to create up to 2500 jobs and add as much as $65 million a year to the economy. To date, Australia has made the major investment for building the ring of the synchrotron, which is to be constructed on the Monash University Campus, and is projected to become operational in 2007. The performance parameters of the design include the following:
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