Inelastic-scattering tunnel electrons towards an electrically driven single-photon light source (Conference Presentation)

Microfabrication is a kind of critical technology for the development of Micro Electro-Mechanical Systems (MEMS). The frequently-used microfabrication technologies are electric discharge machining, photoetching, LIGA and laser fabrication, et al. Micro structures may be fabricated by these technologies. The polymerization principle of two-photon of femtosecond laser is different from that of single-photon. Photoinitiator of photosensing material absorbs two photons simultaneously to accomplish energy level transition and to induce the material to occur photochemical reaction. For the material absorbing two photons, the energy of each photon is equivalent to half of the energy that needed by the material transiting from ground state to excited state. It is also equal to half of the energy needed by the material occurring single-photon absorption. Therefore, the photonic frequency of two-photon excitation light source is half of the single-photon light source. According to two-photon fabrication principle, machining system of two-photon of femtosecond laser is set up. Which includes light path transmission equipment, three dimensional micro displacement scanning stage and control software, et al. Involute micro gear is fabricated by two-photon of femtosecond laser generated by the system.

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Current and future detector developments at the Swiss Light Source

Acta Crystallographica Section A Foundations and Advances ◽

10.1107/s205327331409319x ◽

2014 ◽

Vol 70 (a1) ◽

pp. C680-C680

Author(s):

Bernd Schmitt ◽

Anna Bergamaschi ◽

Sebastian Cartier ◽

Roberto Dinapoli ◽

Dominic Greiffenberg ◽

...

Keyword(s):

Light Source ◽

Dynamic Range ◽

Single Photon ◽

Photon Counting ◽

Low Noise ◽

Pixel Size ◽

Present Measurement ◽

Single Photon Counting ◽

Pixel Detectors ◽

Swiss Light Source

The detector group of the Swiss Light Source (SLS) at the Paul Scherrer Institut (PSI) has a long history of x-ray detector developments for synchrotrons. Initially these detectors were all single photon counting systems. In the last years the focus at PSI was moving towards charge integrating systems mainly driven by the detector needs for the upcoming XFELs. Charge integrating systems however also solve some of the problems of single photon counting systems. Charge integrating systems have an almost infinite linear count rate capability, allow systems with smallest pixel sizes and for low photon energies. In this presentation we give an overview of the detector developments at PSI and focus on Jungfrau, Mönch and Eiger. Eiger is a single photon counting system specifically developed for high frame rates. It has a 75 micron pixel size and can run at frame rates up to 24 kHz. A 9M Eiger detector will be installed in a few months at the cSAXS beamline of the SLS. Jungfrau uses the same sensor as Eiger (about 4cm x 8 cm with a pixel size of 75 microns). It has a charge integrating architecture with dynamic gain switching to achieve a dynamic range of 10^4 photons (at 12 keV). With a frame rate of up to 2 kHz Jungfrau is currently being developed for applications at both XFELs and synchrotrons. 16M Jungfrau detectors are foreseen at the SwissFEL. Mönch is currently a research project. A first prototype with 160x160 pixels and a pixel size of 25 microns was designed and is currently characterised. It offers the smallest pixel size of current hybrid pixel detectors and also has a very low noise allowing hybrid pixel detectors to be used down to about 400eV. We present measurement results for Jungfrau, Mönch and Eiger and give an outlook on future possible systems.

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