X-ray targets for generating x-ray radiation from a waveguide
These innovative multilayer x-ray targets allow the generation of x-ray radiation based on direct emission of spontaneous x-rays into waveguide modes. Photons are generated by electron impact onto a structured anode target, which is formed as an x-ray waveguide or waveguide array.
Challenge
X-ray sources usually emit radiation in a 360° solid angle. Since there are no diffractive, refractive and only a few, very complex reflective optics in this low wavelength range, it is difficult to collect and refocus the radiation. Therefore usually most of the emitted light is lost for the desired application.
Our solution
This invention now proposes a novel X-ray source concept based on the direct emission of X-ray photons in X-ray waveguides. The inventors showed direct emission of characteristic and bremsstrahlung radiation into a waveguide. They directly generate x-rays inside a waveguide by an electron beam. This approach is fundamentally different from first generating the x-rays and then coupling into the waveguide and results in pronounced peaks in the angular far-field distribution which changes also with the distance between the exciting e-beam and the side edge of the waveguide. The radiation generated in the newly developed target is very brilliant, coherent and is emitted directionally. Thus, instead of first generating a beam in an X-ray tube and then laboriously coupling it into a waveguide, the X-ray photons are generated directly in a patterned anode target that also acts as an X-ray waveguide or waveguide array. The coherent and brilliant X-ray light generated in this way can be produced in a laboratory source and is therefore an alternative to synchrotron radiation, which is usually not available at all times due to fixed beam times that have to be requested.
An e-beam (e) impinges onto a planar waveguide. The electron impact excites atoms, which emit characteristic x-rays and bremsstrahlung into the waveguide. (source: M. Vassholz and T. Salditt, Georg-August-Universität Göttingen)
Advantages
- Directed and spatially coherent X-ray emission from waveguide anode
- Generation of X-rays with high brightness and high spatial coherence
- Decoupled size of electron beam and X-ray source
- Integrated optics into an X-ray source target
- Brilliance up to ~ 10¹¹ ph/(s mrad² mm²) with suited heat-management
- Usable in laboratory sources and therefore an alternative to synchrotron radiation
- Creation of 1D and 2D planar waveguide anodes possible
Applications
- Creation of directed and spatially coherent X-ray emission
- New possibilities for X-ray quantum optics
- Benefits for coherent imaging y removing the need for synchrotron radiation
Development Status
Targets successfully produced and function verified, current testing in different sources
Patent Status
Patent holder: Georg-August-Universität Göttingen
DE102020109906B4 (granted)
WO2021204846A1 (disclosed)
References
M. Vassholz et al. - Science Advances 7.4 (2021)
Contact
Dr. Maria Kamper
Patent Manager Physics / Techninology
E-Mail: mkamper(at)sciencebridge.de
Tel.: +49 551 30724 159
Reference: CPA-2224-SUG
Tags: Laser physics and optics, Physics and Technology & Software
