Double ionization of helium by 6 MeV proton impact has been explored in a kinematically complete experiment using a “reaction microscope.” For the first time, fully differential cross sections for positively charged projectiles have been obtained and compared with data from 2 keV electron impact. The significant differences observed in the angular distribution of the ejected electrons are attributed to the charge sign of the projectile, resulting in different dynamics of the four-particle Coulomb system, which is not considered in the first Born approximation.
D. Fischer and R. Moshammer and A. Dorn and J. R. Crespo Lopez-Urrutia and B. Feuerstein and C. Hohr and C. D. Schroter and S. Hagmann and H. Kollmus and R. Mann and B. Bapat and J. H. Ullrich and H. Kollmus, "Projectile-Charge Sign Dependence of Four-Particle Dynamics in Helium Double Ionization," Physical Review Letters, vol. 90, no. 24, pp. 243201/1-243201/4, American Physical Society (APS), Jun 2003.
The definitive version is available at https://doi.org/10.1103/PhysRevLett.90.243201
Keywords and Phrases
Charged Particles; Helium; Ionization Of Gases; Kinematics; Protons; Four Particle Dynamics; Helium Double Ionization; Projectile Charge Sign; Molecular Dynamics
International Standard Serial Number (ISSN)
Article - Journal
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