Speaker
Petr Bilek
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/O5.304.pdf
Simulation of electron interactions with liquid water and processes related
to sub-nanosecond electrical breakdown
P. Bílek1 , M. Šimek2 , T. Hoder1 , Z. Bonaventura1
1 Department of Physical Electronics, Faculty of Science, Masaryk University, Brno, Czechia
2 Department of Pulse Plasma Systems, Institute of Plasma Physics, Academy of Sciences of
the Czech Republic, Prague, Czech Republic
Initiation of electric discharge in dielectric liquids such as water can be caused either by
formation of gaseous bubbles (when the system is driven by high-voltage waveforms of mi-
crosecond duration) or due to creation of cavitation voids in case of very-steep high-voltage
pulses with sub-nanosecond rise times. Presence of these deformations prolong mean-free path
of electrons, which can then gain enough energy for excitation/ionization/dissociation of water
molecules. We propose to use Geant4-DNA [1, 2] toolkit for studies of elementary processes
related to interaction of accelerated electrons with liquid water. The Geant4-DNA provides a
complete set of models describing the step-by-step physical electromagnetic interactions of
electrons with liquid water. These models describe both the cross sections and the final states of
the physical interactions, with a full description of the interaction products, taking into account
the molecular structure of liquid water. Geant4-DNA electron models for the calculation of ion-
ization and excitation cross sections are based on the Emfietzoglou model [3] of the dielectric
function of liquid water. The dielectric function approach is currently the state-of-the-art tech-
nique for modeling the energy-loss of low-energy electrons in the condensed phase [4]. The aim
of our work will be to study elementary processes related to interaction of electrons with liquid
water. Basic parameters such as stopping distance and electron bremsstrahlung spectra will be
determined for given voltage pulse conditions and confronted with experimental data aquired in
point-plane electrode geometry [5, 6].
This research has been supported by the Czech Science Foundation research project 18-04676S.
References
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(2017).
