Unified model of secondary electron cascades in diamond

Journal Article · Tue Mar 15 04:00:00 EST 2005 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.1853494· OSTI ID:20668259

Ziaja, Beata; London, Richard A; Hajdu, Janos ^[1]

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1. Department of Theoretical Physics, Institute of Nuclear Physics, Radzikowskiego 152, 31-342 Cracow (Poland)

In this article we present a detailed and unified theoretical treatment of secondary electron cascades that follow the absorption of x-ray photons. A Monte Carlo model has been constructed that treats in detail the evolution of electron cascades induced by photoelectrons and by Auger electrons following inner shell ionizations. Detailed calculations are presented for cascades initiated by electron energies between 0.1 and 10 keV. The present article expands our earlier work [B. Ziaja, D. van der Spoel, A. Szoeke, and J. Hajdu, Phys. Rev. B 64, 214104 (2001), Phys. Rev. B 66, 024116 (2002)] by extending the primary energy range, by improving the treatment of secondary electrons, especially at low electron energies, by including ionization by holes, and by taking into account their coupling to the crystal lattice. The calculations describe the three-dimensional evolution of the electron cloud, and monitor the equivalent instantaneous temperature of the free electron gas as the system cools. The dissipation of the impact energy proceeds predominantly through the production of secondary electrons whose energies are comparable to the binding energies of the valence (40-50 eV) and of the core electrons (300 eV). The electron cloud generated by a 10 keV electron is strongly anisotropic in the early phases of the cascade (t{<=}1 fs). At later times, the sample is dominated by low energy electrons, and these are scattered more isotropically by atoms in the sample. Our results for the total number of secondary electrons agree with available experimental data, and show that the emission of secondary electrons approaches saturation within about 100 fs following the primary impact.

• OSTI ID: 20668259
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 6 Vol. 97; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABSORPTION
ANISOTROPY
AUGER ELECTRON SPECTROSCOPY
BINDING ENERGY
COUPLING
CRYSTAL LATTICES
DIAMONDS
ELECTRON EMISSION
ELECTRON GAS
ELECTRONS
EV RANGE 10-100
EV RANGE 100-1000
EXPERIMENTAL DATA
HOLES
INNER-SHELL IONIZATION
KEV RANGE 01-10
MONTE CARLO METHOD
THREE-DIMENSIONAL CALCULATIONS
UNIFIED MODEL
X-RAY PHOTOELECTRON SPECTROSCOPY