Using Nuclear Resonance Excitation to Observe United Atoms in Symmetric Ion-Atom Collisions

Abstract

SummaryWe consider nuclear resonance excitation as a means to observe the distribution of united-atom orbitals in symmetric ion-atom collisions. We develop this possibility with the application of a two-state adiabatic model to an analysis of a 8Be nuclear resonance experiment. To test our model, and to provide a more direct determination of the nuclear resonance widtn, we propose that the 8Be expeririment be repeated with metastabDle helium targets.

Atomic effects on α-α scattering to the 8Be ground state

“…Feagin and Kocbach [9] based on a molecular orbital model. This model describes evolution of the He + ion plus He ~ atom into Be + states of (ls)22p and 1s(2p) 2 configurations with respective binding energies E** = 386 and 256 eV and equal population probabilities (b~=b~=0.50).…”

“…We therefore concluded that none of the available models could reproduce the data. Indeed, the Zfirich group [4] as well as Feagin and Kocbach [9] had pointed out that inelastic electron channels also could contribute to the scattering process. In these inelastic channels one or several (up to 3) electrons could be promoted into the continuum.…”

“…This model analysis, together with a convolution of the theoretical curves with the experimental resolution A E, led to the resonance parameters quoted above. However, subsequent analyses [8][9][10] based on atomic physics models could not reproduce the data (e.g. dotted curve in Fig.…”

“…1 with a "best" fit for F R = 5.0 eV) and questioned the validity of the values quoted for the resonance parameters. It was suggested [8][9][10] that improved e-c~ elastic scattering data to the aBe ground state were highly desirable. Such improved data are reported here.…”