Artículo
Importance of considering helium excited states in He + scattering by an aluminum surface
Fecha de publicación:
11/2014
Editorial:
American Physical Society
Revista:
Physical Review B
ISSN:
0163-1829
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
The He+/Al system is a very interesting projectile-surface combination which was thought initially as an example of a pure Auger neutralization mechanism. Then, because of the measured reionization explained by the antibonding interaction of the projectile state with the core target states, the resonant charge exchange with the band states was considered as another important contribution to the neutralization. Nevertheless, by only considering the neutralization to the ground state of helium, the measured ion survival probability is still overestimated. On the other hand, measurements of electron emission from an Al surface bombarded by He positive ions suggested the possibility of occupied excited states of helium due to the ion-surface collision. In this work, we also include the excited states of He within the time-dependent scattering process in which both neutralization mechanisms, resonant and Auger, are simultaneously contemplated. Our starting point is a multiorbital Anderson Hamiltonian projected over the selected space of ground and excited atomic configurations. An extra term related to the Auger mechanism is added to this Hamiltonian. A difference with previous works is that this approach includes the electron spin and, therefore, the spin fluctuation statistics in the charge-exchange process is correctly taken into account. We find a notable improvement in the agreement with the experiments and also that the interference between both mechanisms is not dramatic.
Archivos asociados
Licencia
Identificadores
Colecciones
Articulos(IFIS - LITORAL)
Articulos de INST.DE FISICA DEL LITORAL
Articulos de INST.DE FISICA DEL LITORAL
Articulos(SEDE CENTRAL)
Articulos de SEDE CENTRAL
Articulos de SEDE CENTRAL
Citación
Iglesias Garcia, Adalberto de Jesus; Garcia, Evelina Andrea; Goldberg, Edith Catalina; Importance of considering helium excited states in He + scattering by an aluminum surface; American Physical Society; Physical Review B; 90; 19; 11-2014; 195416-195416
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