title: Double-to-single target ionization ratio for electron capture in fast p-He collisions.
abstract: We have used the ion storage ring CRYRING and its internal gas-jet target and recoil-ion-momentum spectrometer to measure absolute cross sections for transfer ionization (TI: p+He-->H0+He2++e(-)) in 2.5-4.5 MeV p-He collisions with separate Thomas (TTI) and kinematic (KTI) TI contributions. The probability for electron emission in kinematical capture decreases with increasing velocity and appears to approach the photoionization shakeoff value (1.63%) [T. Aberg, Phys. Rev. A 2, 1726 (1970)]]. The velocity dependence of the TTI cross section is consistent with the theoretically predicted v(-11) scaling [J. S. Briggs and K. Taulbjerg, J. Phys. B 12, 2565 (1979)]].
authors.affiliation: Department of Physics, Stockholm University, Sweden.
authors.forename: H T
authors.initials: HT
authors.lastname: Schmidt
authors.forename: A
authors.initials: A
authors.lastname: Fardi
authors.forename: R
authors.initials: R
authors.lastname: Schuch
authors.forename: S H
authors.initials: SH
authors.lastname: Schwartz
authors.forename: H
authors.initials: H
authors.lastname: Zettergren
authors.forename: H
authors.initials: H
authors.lastname: Cederquist
authors.forename: L
authors.initials: L
authors.lastname: Bagge
authors.forename: H
authors.initials: H
authors.lastname: Danared
authors.forename: A
authors.initials: A
authors.lastname: Källberg
authors.forename: J
authors.initials: J
authors.lastname: Jensen
authors.forename: K-G
authors.initials: KG
authors.lastname: Rensfelt
authors.forename: V
authors.initials: V
authors.lastname: Mergel
authors.forename: L
authors.initials: L
authors.lastname: Schmidt
authors.forename: H
authors.initials: H
authors.lastname: Schmidt-Böcking
authors.forename: C L
authors.initials: CL
authors.lastname: Cocke