Early stage of the electron kinetics in swift heavy ion tracks in dielectrics

Journal Article · Wed Sep 15 00:00:00 EDT 2010 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.82.125425· OSTI ID:21421429

Medvedev, N A; Rethfeld, B ^[1]; Volkov, A E ^[2]; Shcheblanov, N S ^[2]

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1. Department of Physics and Research Center OPTIMAS, Technische Universitaet Kaiserslautern, Erwin-Schroedinger-Str. 46, D-67663 Kaiserslautern (Germany)
2. Russian Research Centre 'Kurchatov Institute', Kurchatov Sq. 1, 123182 Moscow (Russian Federation)

A Monte Carlo approach was applied for simulations of the early stage (first tens of femtosecond) of kinetics of the electronic subsystem of silica (SiO{sub 2}) in tracks of swift heavy ions (SHIs) decelerated in the electronic stopping regime. At the first step multiple ionizations of target atoms by a projectile (Ca{sup +19}, E=11.4 MeV/amu) were described that gave the initial spatial distributions of free electrons having different momenta as well as distributions of holes in different atomic shells. Spatial propagation of fast electrons results in secondary ionizations of target atoms as well as in energy transfer to the lattice at times much shorter than the times of atomic oscillations (phonons). The well detected front of excitation in the electronic and ionic subsystems is formed due to this propagation which cannot be described by models based on diffusion mechanisms (e.g., parabolic equations of heat diffusion). At times {approx}10 fs after the projectile passage, about {approx}0.1% of the energy is already transferred to the lattice. About 63% of the energy deposited by the ion is accumulated in holes at these times. Calculated distributions of these holes through the atomic shells are in excellent agreement with the spectroscopy experiments. Comparison with these experiments demonstrated also that relaxation of the electronic subsystem in SHI tracks in solids cannot be described adequately without taking into account intra-atomic and interatomic Auger (Knotek-Feibelman) processes.

• OSTI ID: 21421429
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Vol. 82, Issue 12; Other Information: DOI: 10.1103/PhysRevB.82.125425; (c) 2010 The American Physical Society; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CALCIUM IONS
COMPARATIVE EVALUATIONS
DIELECTRIC MATERIALS
DIFFUSION
ELECTRONIC STRUCTURE
ELECTRONS
ENERGY TRANSFER
EXCITATION
HEAVY IONS
IONIZATION
MEV RANGE 10-100
MONTE CARLO METHOD
OSCILLATIONS
RELAXATION
SILICON OXIDES
SIMULATION
SOLIDS
SPATIAL DISTRIBUTION
SPECTROSCOPY
CALCULATION METHODS
CHALCOGENIDES
CHARGED PARTICLES
DISTRIBUTION
ELEMENTARY PARTICLES
ENERGY RANGE
ENERGY-LEVEL TRANSITIONS
EVALUATION
FERMIONS
IONS
LEPTONS
MATERIALS
MEV RANGE
OXIDES
OXYGEN COMPOUNDS
SILICON COMPOUNDS