Compact X-ray Lasers from Plasmas
Short-wavelength carries advantages for spectroscopy: (i) direct single-photon ionization for sensitive electron or ion detection; (ii) nano-scale spatial resolution, thanks to a tighter focus, for high-resolution imaging. The challenge to realize XUV/X-ray lasing in tiny setups is addressed, to make the short-wavelength lasing potentials at hand.
Tabletop Beams for Short Wavelength Spectrochemistry
Spectrochemistry is the instrumental analysis of substances with light pulses. High brightness beams such as lasers, capillary discharges, etc. have dramatically contributed to the advancement of spectrochemistry, and largely replaced traditional continuous wave lamps. To extend this progress, intense pulses of even shorter wavelengths than state-of-the-art, such as in the extreme ultraviolet or soft/hard X-ray regions, are necessary. With that, one is able to carry out tabletop spectroscopy with high resolution in space, time and frequency. Unfortunately, such advanced beams are not yet commercially available but only found at synchrotron beamlines. Here, the user access is discontinuous, granted to large teams (”big science”), and mainly dedicated to proof-of-principle experiments. To fill the 24/7 gap between users and tools, prototypes of high-brightness short-wavelength sources for tabletop operation, have been developed. Complementary figures-of-merit make them unique for specific high resolution domains, such as generating tunable hard X-rays, monochromatic lines, or ultrafast pulses.
Empulse: A Compact Chirped-Pulse Amplification Terawatt System
A tabletop X-ray source based on laser-produced plasmas (LPP) for round the clock advanced spectroscopy is being developed based on chirped pulse amplification (CPA). The technique permits to obtain pump pulses in the Terawatt. CPA is known for the Physics Nobel prize 2018. The building blocks of the setup are gradually amplifying a seed femtosecond pulse of a few nanojoules on a compact footprint. The results from the front-end are such that this is the most energetic laser installation in Switzerland. The progress on the amplification stages is obtained with a scheme to extract up to 30 J laser pulses of a ps in duration. At the output the pulses hit on rotating target for generating a plasma to lead to population inversion (Ne-like or Ni-Like): as such to enable the emission of Soft X-rays. Soft X-rays laser lines form different targets will be characterized and used for different spectroscopy experiments. A conceptual artist's view of the system is shown here below.