Helmholtz Young Investigator Group - Dominik Kraus
Dynamic Warm Dense Matter Research with HIBEF
"Warm Dense Matter" (WDM) is the name of the transition regime between cold solid or liquid matter and very hot plasmas. With temperatures from several thousand to several hundred thousand Kelvins and densities around solid-state density, resulting in pressures from several thousand to several million atmospheres, a detailed investigation of matter under these extreme conditions is a young and highly evolving field of physics.
A better understanding of the WDM state is highly desirable for astrophysics to e.g. improve modeling of the internal structure and evolution of planets, brown dwarfs and stars. Particularly, chemical processes in warm dense mixtures of light elements in the interior of planets strongly influence the magnetic field and surface temperature, which are important observables for models of planets in our and other solar systems. Moreover, WDM conditions were present within giant impacts during the early stages of our solar system, which defined the planetary structure up to creating the environment necessary for life on our planet. Finally, WDM conditions can be found as a transient state in every laboratory experiment where a solid-state sample is transferred quickly to a plasma state, prominent examples being intense laser-matter interaction as well as high-performance material and radiation damage research.
Robust physical models with predictive capabilities of the WDM regime are very challenging for various reasons . On the one hand, the temperature is in the order of the Fermi energy and thus, WDM cannot be described with methods of classical solid state physics (T~0) or plasma physics (T>>TF). On the other hand, the thermal energy is similar to the ionization energy of valence electrons and chemical bonding energies, leading to partial ionization of the atoms. The resulting ions remain in a strongly coupled state with remnants of solid or liquid structure, given by highly complex ion-ion interaction potentials.
The controlled creation and even more the precise diagnosis of dynamic processes in WDM is extremely challenging. High-quality experiments require homogeneous samples, extreme temporal resolution and need to cover a broad parameter space. Since WDM samples are usually opaque for optical light, most brilliant X-ray sources are required for high-quality experiments. For a complete characterization, “over-diagnosis”, i. e. determining the same observable with different methods at the same time, is highly desirable, since most methods to determine WDM quantities are based on assumptions or require sophisticated theoretical models. This is especially true for measurements in non-equilibrium conditions. The combination of X-ray free electron lasers with high-energy/high-power optical lasers has shown to be capable of WDM experiments of unprecedented quality in terms of precision and time resolution. The HED experimental area at European XFEL equipped with HIBEF will set new standards here and our group is working towards first experiments at this facility to gain unprecedented insights into the dynamic properties of Warm Dense Matter.
MSc / BSc positions will be available soon.
Contact Dominik Kraus for further information.
- D. Kraus, A. Ravasio, M. Gauthier, D. O. Gericke, J. Vorberger, S. Frydrych, J. Helfrich, L. B. Fletcher, G. Schaumann, B. Nagler, B. Barbrel, B. Bachmann, E. J. Gamboa, S. Göde, E. Granados, G. Gregori, H. J. Lee, P. Neumayer, W. Schumaker, T. Döppner, R. W. Falcone, S. H. Glenzer, M. Roth
Nanosecond formation of diamond and lonsdaleite by shock compression of graphite
Nature Communications 7, 10970 (2016)
- D. Kraus, D. A. Chapman, A. L. Kritcher, R. A. Baggott, B. Bachmann, G. W. Collins, S. H. Glenzer, J. A. Hawreliak, D. H. Kalantar, O. L. Landen, T. Ma, S. Le Pape, J. Nilsen, D. C. Swift, P. Neumayer, R. W. Falcone, D. O. Gericke, T. Döppner
X-ray scattering measurements on imploding CH spheres at the National Ignition Facility
Physical Review E 94, 011202(R) (2016)
- D. Kraus, J. Vorberger, J. Helfrich, D. O. Gericke, B. Bachmann, V. Bagnoud, B. Barbrel, A. Blazevic, D. C. Carroll, W. Cayzac, T. Döppner, L. B. Fletcher, A. Frank, S. Frydrych, E. J. Gamboa, M. Gauthier, S. Goede, E. Granados, G. Gregori, N. Hartley, B. Kettle, H. J. Lee, B. Nagler, P. Neumayer, M. M. Notley, A. Ortner, A. Otten, A. Ravasio, D. Riley, F. Roth, G. Schaumann, D. Schumacher, W. Schumaker, K. Siegenthaler, C. Spindloe, F. Wagner, K. Wuensch, S. H. Glenzer, M. Roth, R. W. Falcone
The complex ion structure of warm dense carbon measured by spectrally resolved x-ray scattering
Physics of Plasmas 22, 056307 (2015)
- D. Kraus, J. Vorberger, D. O. Gericke, V. Bagnoud, A. Blazevic, W. Cayzac, A. Frank, G. Gregori, A. Ortner, A. Otten, F. Roth, G. Schaumann, D. Schumacher, K. Siegenthaler, F. Wagner, K. Wünsch, M. Roth
Probing the complex ion structure of liquid carbon at 100 GPa
Physical Review Letters 111, 255501 (2013)
- A. Frank, A. Blazevic, V. Bagnoud, M. M. Basko, M. Börner, W. Cayzac, D. Kraus, T. Heßling, D. H. H. Hoffmann, A. Ortner, A. Otten, A. Pelka, D. Pepler, D. Schumacher, An. Tauschwitz, M. Roth
Energy Loss and Charge Transfer of Argon in a Laser-Generated Carbon Plasma
Physical Review Letters 110, 115001 (2013)
- T. Bartal, M. E. Foord, C. Bellei, M. H. Key, K. A. Flippo, S. A. Gaillard, D. T. Offermann, P. K. Patel, L. C. Jarrott, D. P. Higginson, M. Roth, A. Otten, D. Kraus, R. B. Stephens, H. S. McLean, E. M. Giraldez, M. S. Wei, D. C. Gautier, F. N. Beg
Focusing of short-pulse high-intensity laser-accelerated proton beams
Nature Physics 8, 139–142 (2012)