Double-to-Single Target Ionization Ratio for Electron Capture in Fastp-He Collisions

H. T. Schmidt, A. Fardi, R. Schuch, S. H. Schwartz, H. Zettergren, H. Cederquist, L. Bagge, H. Danared, A. Källberg, J. Jensen, K.-G. Rensfelt, V. Mergel (+3 others)
2002 Physical Review Letters  
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 ! H 0 He 2 e ÿ ) 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. Å berg, Phys. Rev. A 2, 1726 (1970)].
more » ... e velocity dependence of the TTI cross section is consistent with the theoretically predicted v ÿ11 scaling [
doi:10.1103/physrevlett.89.163201 pmid:12398718 fatcat:l33qsje4jvautivq66obbw44ve