X-ray and Gamma-ray laser-based photon sources

The Gamma Factory project offers the possibility of creating novel research tools by exploiting laser-particle interactions between ultra-relativistic beams of highly ionised atoms in CERN’s accelerator complex and exciting their atomic degrees of freedom by cavity enhanced MW-class average power laser frequency combs. The resulting Gamma-ray beam has an intensity that exceeds by several orders of magnitude the ones offered by the presently operating FEL light sources, in the particularly interesting energy domain from about 100 keV to above 400 MeV.

Representative publications in this area:

Inverse Compton scattering refers to the phenomenon where low-energy photons are scattered by ultrarelativistic electrons, resulting in the photons gaining energy while the electrons lose energy. Unlike the conventional Compton effect, in this process, it's the electrons that lose energy rather than the photons, hence the term "inverse." Thus, inverse Compton scattering is a means of creating very high energy photons in the X-ray and Gamma ray parts of the spectrum.

In our experiments, a photoinjector generated electron beam pulse train is scattered by a recirculating laser pulse in a novel resonant configuration termed "burst-mode Fabry-Perot enhancement cavities." Our works relies on recent developments related to Electro-Optic frequency combs at GHz repetition rates.

Relevant publications in this area:

Light in the extreme ultraviolet (EUV) region of the electromagnetic spectrum covers the 5-50 nm range. Because its wavelength is 100-10 times shorter than visible light it can ‘see’ and ‘write’ smaller patterns in applications such as microscopy and lithography. Furthermore, these wavelengths are well matched to the primary atomic resonances of most elements, making possible many element- and chemically- specific spectroscopies and spectromicroscopies.

Scaling up the average power and pulse energy of ultra-short-pulse lasers is one of the main topics in laser physics. A variety of approaches are investigated, which can and are being combined in a single system to provide ultra-short high-energy pulses at high repetition rates and average powers. This makes these systems suitable for applications like high harmonic generation (HHG) that require high peak powers to work, while the high repetition rates compensate for the low conversion efficiency.