Comment on 'Asymptotic behaviour of the total cross section for double ionization of helium-like ions by electrons'

Defrance et al (Defrance P, Kereselidze T M, Noselidze I L and Tzulukidze M F 2001b J. Phys. B: At. Mol. Opt. Phys. 34 4957-68; Defrance P, Kereselidze T, Noselidze I and Tzulukidze M 2001 a 22nd Int. Conf. on Photonic, Electronic, and Atomic Collisions (Santa Fe, CA) (abstracts of contributed papers) p 315) have reported calculations of the electron-impact double-ionization cross section for helium that display a markedly different high-energy behaviour than do most of the published experimental data and they contend that new precise measurements are needed. The results presented here confirm the correctness of the more recent experimental data and indicate that revision of the theory is required.