Paper: Ultimate limitations in the performance of kinoform lenses for hard X-ray focusing
The science of X-ray focussing becomes clearer thanks to new results from Molecular Imaging researchers
Powerful imaging techniques, which are key for understanding the properties of new materials, and for imaging cells and proteins, rely on using special lenses to focus various forms of light. The ability of scientists to efficiently focus beams of X-rays is important for advanced imaging across many different scientific disciplines. This week scientists tested the long-standing idea that a special type of lens design, known as a kinoform, can increase the efficiency of Fresnel zone plates for focusing X-rays. The work is published in the journal Optica.
The work of the great French Scientist Augustin-Jean Fresnel (1788-1827) led to the development of the Fresnel zone plate, a device that can be used to efficiently focus visible light. It has also long been assumed that certain adaptations to Fresnel lens designs could yield devices suitable for very efficiently focusing X-rays. Manufacturing suitable kinoform Fresnel zone plates to test this idea has, however, proven incredibly difficult.
Recently, by using a focused ion beam – a kind of molecular milling machine – Australian Research Council Imaging Centre researchers were able to successfully produce a kinoform adapted Fresnel zone plate. Science though, rarely takes a straight path and, in collaboration with the Australian Synchrotron – Australia’s brightest X-ray source – the researchers made the surprising finding that such adapted Fresnel zone plates do not work nearly as well as originally predicted.
The researchers found that all the effort to fabricate complex three-dimensional lenses for efficient X-ray focusing did not yield significant enough returns to warrant the effort.
Dr. Sergery Gorelick first author on the paper, from Monash University’s Biomedicine Discovery Institute said “Once you do the mathematics, it is clear why this does not work. The question is why nobody bothered to do it before.”
Lead author Associate Professor Alex de Marco, Associate Investigator on the ARC Centre of Excellence in Advanced Molecular Imaging commented “Probably the biggest challenge we faced was the negative nature of the results, which is generally not well received,” said de Marco, “however, that is what makes this work crucial – once you have learned that a route is a dead end, you start to look around and find other unexplored directions.”
Based on their findings, the researchers are now working towards constructing new, innovative lens designs that they anticipate will have the desired results.
The study was a collaboration between researchers based at Monash University Biomedicine Discovery Institute, the ARC Imaging Centre of Excellence for Advanced Molecular Imaging, ANSTO, La Trobe Institute for Molecular Sciences and the University of Warwick. All measurements were performed at the Australian Synchrotron.
ARC Centre of Excellence in Advanced Molecular Imaging
The $39 million ARC-funded Imaging CoE develops and uses innovative imaging technologies to visualise the molecular interactions that underpin the immune system. Featuring an internationally renowned team of lead scientists across five major Australian Universities and academic and commercial partners globally, the Centre uses a truly multi scale and programmatic approach to imaging to deliver maximum impact.
The Imaging CoE is headquartered at Monash University with four collaborating organisations – La Trobe University, the University of Melbourne, University of New South Wales and the University of Queensland.
Monash Biomedicine Discovery Institute
Committed to making the discoveries that will relieve the future burden of disease, the newly established Monash Biomedicine Discovery Institute at Monash University brings together more than 120 internationally-renowned research teams. The Institute researchers’ are supported by world-class technology and infrastructure, and partner with industry, clinicians and researchers internationally to enhance lives through discovery.
ANSTO is the home of Australia’s most significant landmark and national infrastructure for research. Thousands of scientists from industry and academia benefit from gaining access to state-of-the-art instruments every year.
ANSTO operates much of Australia’s landmark infrastructure including one of the world’s most modern nuclear research reactors, OPAL; a comprehensive suite of neutron beam instruments; the Australian Synchrotron; the National Imaging Facility Research Cyclotron; and the Centre for Accelerator Science.
La Trobe Institute for Molecular Science
The La Trobe Institute for Molecular Science (LIMS) is committed to solving global problems and improving the welfare of human societies.
The Institute embodies La Trobe University’s strategic vision: to be globally recognised for its excellence, creativity and innovation in relation to the big issues of our time.
Launched in 2009, LIMS brings together the University’s leading scientists to create new levels of collaboration, and a multi-disciplinary approach to drive innovation and produce translatable research outcomes.
The LIMS complex has 56 research and support laboratories, advanced research equipment, a 200-seat auditorium, and over 3,000 square metres of teaching facilities. Around 400 La Trobe academics, research fellows, postgraduate students and support staff are based at the Institute. LIMS also has an important regional node: many of its scientists work at La Trobe’s Bendigo campus.
University of Warwick
Born out of boldness, imagination and collaboration, the University of Warwick is a world-leading university with the highest academic and research standards. Committed to attracting and nurturing the very best academics.
University of Warwick researchers are encouraged and supported to collaborate nationally and internationally, to ensure that they continue to address some of the world’s biggest challenges and channel their expertise into making the world healthier, safer, cleaner and more just.
The central pillar of academic research excellence remains publication in high quality journals, or publication of monographs with leading publishers. In a climate where Open Access and Open Research Data are increasingly standard, the University Warwick offer high quality library services, such as WRAP – an open access research repository.
Written by Aimee Sanderson
Contact: Juliana Villa-Ortiz, 0437 119 498, firstname.lastname@example.org
Image by Sergery Gorelick.
The surface of one of the kinoform lenses seen from a Scanning Electron Microscope.