Observation of low-lying resonance states of [Formula Presented] at the [Formula Presented]S and [Formula Presented]S He thresholds

We measured the cusp electron production associated with target ionization at the impact of a 400-keV pure2[Formula Presented]S He beam and a mixed beam containing all three long-lived He states, i.e., 1[Formula Presented]S,n2[Formula Presented]S, and 2[Formula Presented]S. Using the results of an e...

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Detalles Bibliográficos
Publicado: 1997
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_10502947_v55_n1_pR14_Bader
http://hdl.handle.net/20.500.12110/paper_10502947_v55_n1_pR14_Bader
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Sumario:We measured the cusp electron production associated with target ionization at the impact of a 400-keV pure2[Formula Presented]S He beam and a mixed beam containing all three long-lived He states, i.e., 1[Formula Presented]S,n2[Formula Presented]S, and 2[Formula Presented]S. Using the results of an earlier experiment [Kuzel et al., Phys. Rev. A 48, R1745 (1993)], we estimated the cross section for both metastable states of He. We found that the cusp for the 2[Formula Presented]S state is much larger and sharper than for the 2[Formula Presented]S state. The peaks are manifestations of excitation of low-lying virtual or weakly bound states of the [Formula Presented] ion at the 2[Formula Presented]S and 2[Formula Presented]S thresholds. © 1997 The American Physical Society.