Proton stopping in dense molecular hydrogen: A molecular-confinement model
Por:
Cruz S.A., Soullard J., Gamaly E.G.
Publicada:
1 ene 1999
Resumen:
A molecular-confinement model is proposed for the calculation of density effects on the electronic stopping cross section (Se) in a condensed medium. In this model, the collective intermolecular interactions in the medium are represented by a mean field in which a particular molecule is embedded including the spatial constrictions imposed by the surrounding molecules. A molecule is thus viewed as a caged-in system within a spherical boundary with finite potential barrier height VB. Changes in the molecular electronic properties and molecular conformation as a function of medium density are self-consistently treated. As a first example of a general treatment for more complicated target structures, the model is explicitly applied to the case of proton stopping in dense molecular hydrogen. The lowest barrier height (VB=0) was selected for the stopping calculations since it provides a more realistic pressure-density relation at T=0 K than higher barrier values. Our results for dense molecular hydrogen predict a very small to moderate reduction in Se relative to the gas phase in going from atmospheric pressure (0.036 mol/cm3, ?Se?0.5%) up to 136 GPa (0.380 mol/cm3, ?Se?24%) for either the liquid or solid phase as determined by the phase diagram for this medium. ©1999 The American Physical Society.
Filiaciones:
Cruz S.A.:
Programa de Simulación Molecular, Instituto Mexicano del Petroleo, Apartado Postal 14-805, México Distrito Federal, 07730, Mexico
Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, Apartado Postal 55-534, México Distrito Federal, 09340, Mexico
Soullard J.:
Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, México Distrito Federal, 01000, Mexico
Gamaly E.G.:
Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, Apartado Postal 55-534, México Distrito Federal, 09340, Mexico
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