Electronic excitations induced by swift heavy ions can be identified as the main process for the creation of material modifications in insulators. These excited electrons relax via electron-phonon coupling, leading to a local melting of the target. This is often treated within the two-temperature-model (TTM).
In order to investigate these material modifications after swift heavy ion impact, especially the electronic dynamics of the insulator, a combination of the Monte Carlo method (MC), with the TTM is applied.
Within the MC part the projectile penetration and the following excitation and relaxation of the electronic subsystem is simulated, while the MC output is used as initial conditions for the TTM calculations. The benefit of this combined modeling is that often inaccessible material parameters like the electron-phonon-coupling and the electronic diffusivity are directly calculated within the MC part.
It will be demonstrated that the temperature dependent specific heat capacity of the electrons can be calculated allowing to determine the degree of metallization of the insulator after swift heavy ion irradiation.
As a model system we choose the irradiation of SiO2 with Ca+19 ion at 11.4 MeV/u kinetic energy [1,2,3].



[1] P. Kluth, C. S. Schnohr, O. H. Pakarinen, F. Djurabekova,D. J. Sprouster, R. Giulian, M. C. Ridgway, A. P. Byrne, C. Trautmann, D. J. Cookson, Fine Structure in Swift Heavy Ion Tracks in Amorphous SiO2, Phys. Rev. Lett. 101,175503 (2008).
[2] N.Medvedev, A.E. Volkov , B. Rethfeld, N.S. Shcheblanov, NIMB (accepted)
[3] O. Osmani, N. Medvedev, M. Schleberger, B. Rethfeld
e-J. Surf. Sci. Nanotech., Excitation and relaxation of swift heavy ion irradiated dielectrics (acceped)

Orkhan Osmani*, University of Duisburg-Essen, Germany
Nikita Medvedev, Technical University of Kaiserslautern, Germany
Baerbel Rethfeld, Technical University of Kaiserslautern, Germany
Marika Schleberger, University of Duisburg-Essen, Germany

*presenting author