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Title: Calculation of energy-loss straggling of C, Al, Si, and Cu for fast H, He, and Li ions

Abstract

We present theoretical calculations of the energy-loss straggling of C, Al, Si, and Cu targets for H, He, and Li ions in the range of intermediate to high energies (0.01-10 MeV/u). These calculations have been done by employing the dielectric formalism and by considering the different equilibrium charge states of the swift ion inside the solid as a function of its energy. Two different models are used: the Mermin energy-loss functions combined with generalized oscillator strengths (MELF-GOS) and the shellwise application of the local plasma approximation (SLPA). The MELF-GOS describes the target outer-electron excitations through a fitting to experimental data in the optical limit, employing a linear combination of Mermin-type energy-loss functions; the excitations of the inner-shell electrons are taken into account by means of generalized oscillator strengths. The SLPA employs a free-electron-gas model for the target valence electrons and the local density approximation for each shell of target electrons separately by using Hartree-Fock atomic wave functions. The results of the energy-loss straggling obtained by the two independent models show good agreement with the available experimental data. The calculated energy-loss straggling tends at high energies to the Bohr value and takes values below it at intermediate energies. The Bethe-Livingston shouldermore » (or overshooting) at intermediate energies does not appear in the present calculations. We find that the energy-loss straggling normalized to Z{sub P}{sup 2} is almost independent of the ion atomic number Z{sub P}; therefore, the results for H, He, and Li projectiles in each target can be approximated by a universal curve at high energies.« less

Authors:
; ; ; ;  [1];  [2];  [3];  [3]
  1. Instituto de Astronomia y Fisica del Espacio, Casilla de correo 67, Sucursal 28, 1428 Buenos Aires (Argentina)
  2. (Argentina)
  3. (Spain)
Publication Date:
OSTI Identifier:
20982137
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. A; Journal Volume: 75; Journal Issue: 2; Other Information: DOI: 10.1103/PhysRevA.75.022903; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; ALUMINIUM; ATOMIC IONS; CARBON; CHARGE STATES; COMPUTER CALCULATIONS; COPPER; DENSITY FUNCTIONAL METHOD; ELECTRON GAS; ENERGY LOSSES; EXCITED STATES; HARTREE-FOCK METHOD; HELIUM IONS; HYDROGEN IONS; ION-ATOM COLLISIONS; KEV RANGE; LITHIUM IONS; MEV RANGE 01-10; OSCILLATOR STRENGTHS; SILICON; WAVE FUNCTIONS

Citation Formats

Montanari, C. C., Miraglia, J. E., Heredia-Avalos, Santiago, Garcia-Molina, Rafael, Abril, Isabel, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Departamento de Fisica - CIOyN, Universidad de Murcia, Apartado 4021, E-30080 Murcia, and Departament de Fisica Aplicada, Universitat d'Alacant, Apartat 99, E-03080 Alacant. Calculation of energy-loss straggling of C, Al, Si, and Cu for fast H, He, and Li ions. United States: N. p., 2007. Web. doi:10.1103/PHYSREVA.75.022903.
Montanari, C. C., Miraglia, J. E., Heredia-Avalos, Santiago, Garcia-Molina, Rafael, Abril, Isabel, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Departamento de Fisica - CIOyN, Universidad de Murcia, Apartado 4021, E-30080 Murcia, & Departament de Fisica Aplicada, Universitat d'Alacant, Apartat 99, E-03080 Alacant. Calculation of energy-loss straggling of C, Al, Si, and Cu for fast H, He, and Li ions. United States. doi:10.1103/PHYSREVA.75.022903.
Montanari, C. C., Miraglia, J. E., Heredia-Avalos, Santiago, Garcia-Molina, Rafael, Abril, Isabel, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Departamento de Fisica - CIOyN, Universidad de Murcia, Apartado 4021, E-30080 Murcia, and Departament de Fisica Aplicada, Universitat d'Alacant, Apartat 99, E-03080 Alacant. Thu . "Calculation of energy-loss straggling of C, Al, Si, and Cu for fast H, He, and Li ions". United States. doi:10.1103/PHYSREVA.75.022903.
@article{osti_20982137,
title = {Calculation of energy-loss straggling of C, Al, Si, and Cu for fast H, He, and Li ions},
author = {Montanari, C. C. and Miraglia, J. E. and Heredia-Avalos, Santiago and Garcia-Molina, Rafael and Abril, Isabel and Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and Departamento de Fisica - CIOyN, Universidad de Murcia, Apartado 4021, E-30080 Murcia and Departament de Fisica Aplicada, Universitat d'Alacant, Apartat 99, E-03080 Alacant},
abstractNote = {We present theoretical calculations of the energy-loss straggling of C, Al, Si, and Cu targets for H, He, and Li ions in the range of intermediate to high energies (0.01-10 MeV/u). These calculations have been done by employing the dielectric formalism and by considering the different equilibrium charge states of the swift ion inside the solid as a function of its energy. Two different models are used: the Mermin energy-loss functions combined with generalized oscillator strengths (MELF-GOS) and the shellwise application of the local plasma approximation (SLPA). The MELF-GOS describes the target outer-electron excitations through a fitting to experimental data in the optical limit, employing a linear combination of Mermin-type energy-loss functions; the excitations of the inner-shell electrons are taken into account by means of generalized oscillator strengths. The SLPA employs a free-electron-gas model for the target valence electrons and the local density approximation for each shell of target electrons separately by using Hartree-Fock atomic wave functions. The results of the energy-loss straggling obtained by the two independent models show good agreement with the available experimental data. The calculated energy-loss straggling tends at high energies to the Bohr value and takes values below it at intermediate energies. The Bethe-Livingston shoulder (or overshooting) at intermediate energies does not appear in the present calculations. We find that the energy-loss straggling normalized to Z{sub P}{sup 2} is almost independent of the ion atomic number Z{sub P}; therefore, the results for H, He, and Li projectiles in each target can be approximated by a universal curve at high energies.},
doi = {10.1103/PHYSREVA.75.022903},
journal = {Physical Review. A},
number = 2,
volume = 75,
place = {United States},
year = {Thu Feb 15 00:00:00 EST 2007},
month = {Thu Feb 15 00:00:00 EST 2007}
}