They can be bent after all: In defiance of a decades-old assumption, gamma-rays can be focused with lenses. The discovery opens up a range of potential applications – from monitoring of nuclear waste to new cancer therapies.
Gamma-rays are extremely powerful electromagnetic waves that are far more energetic than visible light. Physicists have long assumed that gamma radiation cannot be refracted by lenses, and thus cannot be manipulated optically. In contrast, optics with X-rays was shown to be feasible in the mid-1990s.
In experiments carried out at the Institut Laue-Langevin (ILL) in Grenoble, researchers led by the physicist ProfessorDieter Habsof LMU Munich and the Max Planck Institute for Quantum Optics in Garching have now shown that lenses made of silicon can focus gamma-rays just like visible light. The effect is due to the interaction between the gamma-rays and the strong electric fields associated with silicon nuclei.
“Our findings open up an entirely new dimension in optics,” says Professor Habs. “We have, as it were, found spectacles that will make it possible to exploit gamma-rays for a range of applications.” Gamma-ray detectors for ultra-precise characterization of materials are but one example. “Gamma-rays are ten to a thousand times more energetic than X-rays and can penetrate very dense materials. One could even perform remote imaging of individual atoms – an important advantage for the detection of radioactive materials, for instance“, he explains.
Habs also envisages future applications in medicine. Monitoring of the distribution of chemotherapeutic drugs in the body would allow dosages to be adjusted as required. The degree of refraction achieved with the lenses used so far is relatively low. In future, Habs and his team plan to use lenses made of gold. Because the electric fields near gold nuclei exceed those in silicon atoms, the researchers expect the gamma-rays to be deflected to a greater extent by the former. The experiments with gold lenses will begin in the summer.
Photosynthesis: varying roads lead to the reaction center
Photosynthesis is the motor of all life on Earth. Complex processes are required for the sunlight-powered conversion of carbon dioxide and water to energy-rich sugar and oxygen. These processes are driven by two protein complexes, photosystems I and II. In photosystem I, sunlight is used wi ... more
Microscopy: highest resolution in three dimensions
Super-resolution microscopy methods are essential for uncovering the structures of cells and the dynamics of molecules. Since researchers overcame the resolution limit of around 250 nanometers (and winning the 2014 Nobel Prize in Chemistry for their efforts), which had long been considered ... more
The chemistry of mummification
A international team of researchers from LMU and University of Tübingen is unveiling the secrets of ancient Egyptian embalming. Vessels from a workshop in Saqqara are providing new insights into the substances that were used to preserve human bodies. Exactly 100 years ago, the tomb of Tutan ... more
Magnetic nanoparticles change their magnetic structure in a magnetic field
When ultrafine magnetic particles are exposed to an external magnetic field, their magnetic core grows in a previously unexpected way. This was observed by a team of scientists from the University of Cologne (UoC), Forschungszentrum Jülich and the Institut Laue-Langevin in Grenoble, France, ... more
The Institut Laue-Langevin is an international research centre at the leading edge of neutron science and technology. The Institute operates the most intense neutron source in the world, feeding intense beams of neutrons to a suite of 40 high-performance instruments that are constantly upg ... more
Quantum simulator enables first microscopic observation of charge carriers pairing
A team of researchers at the MPQ has for the first time monitored in an experiment how holes (positive charge carriers) in a solid-state model combined to form pairs. This process could play an important role in understanding high-temperature superconductivity. Using a quantum simulator, re ... more
When light impinges on molecules, it is absorbed and re-emitted. Advances in ultrafast laser technology have steadily improved the level of detail in studies of such light-matter interactions. FRS, a laser spectroscopy method in which the electric field of laser pulses repeating millions of ... more
Pumping up the music of molecules
Sensitive animal noses can sniff out trace particles, such as volatile organic compounds, in the ambient air. Humans, on the other hand, are developing innovative technologies for this purpose, such as optical spectroscopy. This uses laser light to detect the molecular composition of gases. ... more
Max-Planck-Institut für Quantenoptik
Research at the Max Planck Institute of Quantum Optics concentrates on the interaction of light and matter under extreme conditions. One focus is the high-precision spectroscopy of hydrogen. In the course of these measurements Prof. Theodor W. Hänsch developed the frequency comb technique f ... more
