Innovation Award Berlin Brandenburg for femtosecond X-ray source for the investigation of molecular structures in real time

Together with the IfG Institute for Scientific Instruments GmbH, the Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy (MBI) for the development of a laser driven x-ray plasma source was awarded the 2010 Innovation Prize. The new compact device - powered by a high-intensity short-pulse laser system - delivers pulses of hard X-rays with an extremely short duration of 100 fs (1 fs = 10-15s, 1 billionth of a millionth of a second) and a kilohertz repetition rate. These X-ray pulses are synchronized with the optical pulses of the laser system used and allow the implementation of X-ray diffraction experiments highest time resolution. "The success is the result of the close exchange and intensive cooperation of basic researchers and engineers at the Berlin-Adlershof location," emphasized Prof. Norbert Langhoff (IfG) and Prof. Thomas Elsässer (MBI) in accepting the prize.

In many fields, such as molecular biology, nanotechnology or sensor technology, fundamental properties and technical functions are associated with movements of molecules or atomic layers. These take place extremely fast in an unimaginably small space. In order to understand such processes and optimize their function, you have to make their process visible. This requires a 'camera' that produces an ultrafast sequence of snapshots of the system and thus maps its current structure. This dream can be realized with the excellent femtosecond X-ray plasma source, which allows the direct imaging of ultrafast atomic and molecular movements with maximum time resolution.

Ultra-short x-ray pulses are generated in the plasma source by the irradiation of a metal target, e.g. a copper strip, produced with high-intensity ultrashort light pulses from a commercial laser system. In the high electric field of the laser pulses, electrons are strongly accelerated and, after penetrating into the metal, produce so-called characteristic X-rays, similar to the principle of a conventional X-ray tube. Since the driving laser pulse lasts only about 50 fs, the acceleration of the electrons and thus the duration of X-ray generation are limited to this extremely short time interval. To produce a sequence of x-ray snapshots, the process to be investigated is started with an ultrashort light pulse and the x-ray pulse is diffracted at a specific delay time on the excited sample. By varying the delay time in the experiment, a sequence of snapshots, the 'X-ray movie', is created.

The technology developed here is internationally unrivaled and has contributed significantly to MBI's leading role in time-resolved structural research. For example, the femtosecond diffraction of crystalline powders in the specialist press, which was recently demonstrated for the first time, was recognized as an outstanding breakthrough. The work on the MBI will i.a. funded by an Advanced Grant for Pioneering Frontier Research of the European Research Council. As a new field of application, the innovation opens up materials research, nanotechnology, chemistry and pharmacy. The device has been realized four times, ggw. Sales negotiations are conducted with four other customers. The turnover amounts to approx. 2 million euros net.