cosine is developing a new lens for focusing hard X-ray and gamma radiation. This lens could help make radiation therapy for cancer patients more accurate. The lens makes use of the Silicon Pore Optics technology developed at cosine for the Athena X-ray telescope of the European Space Agency.
cosine develops X-ray mirrors primarily for the Athena X-ray telescope of the European Space Agency that is scheduled to be launched into space in 2031. Even though these mirrors are developed to reflect X-rays, the same principle can be applied to focusing gamma rays. These silicon mirror plates can be used to create a lens for much higher energy radiation, from 100 keV till 500 keV, opening up new applications.
High spot concentration of radiation
“It is very difficult to reflect hard X-rays and gamma rays with a mirror, as they pass through most materials, but they can be reflected from crystal planes”, explains cosine founder and managing director Prof. Dr Marco Beijersbergen. “A so-called Laue lens uses crystals that are arranged to form a lens. However, if you use regular crystals with flat crystal planes, the focal spot will never be smaller than the dimensions of the crystals. And the production of such a lens is difficult and cumbersome.”
For the X-ray telescope Athena, cosine is developing curved mirrors that are made by bending silicon wafers, utilizing production technology which is normally used to produce memory chips. “These wafers are crystalline, but they are also bent, and therefore can focus radiation into a small spot of less than 1 mm3.”
Medical treatment
A possible medical application would be more accurate radiation therapy for cancer patients. Current day radiotherapy equipment uses a large number of gamma-ray sources operating at MeV energy. “The Laue lens not only focuses rays but also acts as a filter, selecting a narrow band pass of wavelength. This is key to replacing dangerous and decaying gamma-ray sources by much safer X-ray tubes”, explains Dr Nicolas Barrière, expert in Laue lenses who has been working at cosine on Silicon Pore Optics for 5 years. “Our gamma-ray lens can enable sub-MeV radiotherapy, which has the potential to cure resilient tumors, while sparing the skin thanks to its focused beam. The radiation dose can be delivered in a small and sharp volume, causing less damage in the surrounding tissue, without production of any radioactive waste. This could be a new and very effective tool for radiation therapy, complementary to existing ones”.
Applications
Whilst the Laue lens is being developed, cosine is looking for partners to bring this technology to the next level. Beijersbergen: “We have developed the technology and are developing the product, but to develop it further for specific applications we need to work together with launching customers. We are looking forward to further developing this technology with a client.”
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