L. Spielberger et al., Cross-section ratio of double to single ionization of helium by Compton scattering of 40-100-keV x rays, PHYS REV A, 59(1), 1999, pp. 371-379
We have measured the ratio of cross sections for double to single ionizatio
n of helium by Compton scattering, R-C = sigma(C)(++)/sigma(C)(+), at photo
n energies of 40, 80, and 100 keV using cold target recoil-ion momentum spe
ctroscopy. Comparison with calculations involving highly correlated initial
states and approximate final states with and without final-state correlati
ons, represented by 3C and 2C wave functions respectively, shows that the i
nfluence of final-state correlations persists to very high photon energies.
A comparison with recent charged-particle data is made. [S1050-2947(99)047
01-0].