Target dependence of binary encounter electron peak anomalies in collisions of partially stripped heavy ions with molecular hydrogen and noble gases

A systematic search was performed for the manifestation of quantum interference effects in the shape and angular distribution of the binary-encounter electron peak in collisions of partially stripped, or structured, heavy ions with noble gases and molecular hydrogen. The ionic species investigated were Cu5+,19+, I7+,23+, Au11+,29+ and U13+, all at the same nominal velocity equivalent to 0.6 MeV amu-1. Experimental double-differential cross sections for secondary electron emission in the binary encounter energy region are compared with a simple model based on the elastic scattering of quasi-free target electrons in the projectile field as well as with results of impulse approximation (IA) calculations. While these calculations provide a good qualitative overall description of the observed quantum effects for noble gas targets, this is not the case for H2 targets. An attempt was made to incorporate target molecular structure into the impulse approximation code by allowing the binary electron amplitudes from each of the hydrogen atoms, assumed to constitute the H2 molecule, to interfere. This approach, while demonstrating the strong influence of molecular orientation upon the intermediate energy region of the cross sections, did not meet with success, thereby indicating the necessity to consider the final-state interaction of the binary electron with the two protons of the residual H2+ or H22+ target.

[1]  L. H. Andersen,et al.  The enhancement of the binary encounter peak for q=1 to Z in collisions of fast Cq+ and Oq+ on H2 , 1994 .

[2]  W. Wolff,et al.  Ionic charge dependence of the zero degree binary encounter peak for partially stripped heavy ions , 1993 .

[3]  W. Wolff,et al.  Transition from quantum to quasi-classical behaviour of the binary encounter peak in collisions of 0.6 to 3.6 MeV amu-1 I23+ and Xe21+ with He and Ar , 1993 .

[4]  W. Wolff,et al.  Dependence of binary encounter electron production on the charge state of the recoil ion , 1993 .

[5]  S. Grabbe,et al.  Binary encounter electrons in ion-atom collisions☆ , 1993 .

[6]  W. Wolff,et al.  Diffraction effects in binary encounter electron production from collisions of partially stripped ions , 1993 .

[7]  Richard,et al.  Effect of exchange on the binary-encounter-electron double-differential cross section in Cq+-H2 collisions at 0.75 MeV/amu. , 1993, Physical review. A, Atomic, molecular, and optical physics.

[8]  W. Wolff,et al.  Pronounced small-angle diffraction in the binary encounter peak in collisions of Au11+ with H2 , 1993 .

[9]  G. Kraft,et al.  Delta-electron emission in fast heavy ion — atom collisions: observations of new phenomena and breakdown of common scaling laws , 1992, Advances in space research : the official journal of the Committee on Space Research.

[10]  W. Wolff,et al.  Diffraction in the binary encounter electron peak observed in collisions of 0.6 MeV amu-1 I7+ I23+ and Au11+ projectiles with He and Ar , 1992 .

[11]  Macek,et al.  Ion-impact ionization of He targets. , 1992, Physical review. A, Atomic, molecular, and optical physics.

[12]  J. Ullrich,et al.  Quasi-discretization of the electron continuum emitted in collisions of 0.6 MeV u-1 Au11+ with noble gases , 1992 .

[13]  Ponce,et al.  Binary-encounter electron production in energetic heavy-bare-ion-atom collisions. , 1992, Physical review. A, Atomic, molecular, and optical physics.

[14]  Wang,et al.  Electron loss at backward observation angles. , 1991, Physical review. A, Atomic, molecular, and optical physics.

[15]  D. Schultz,et al.  Binary peak enhancement and structure in partially stripped ion-atom collisions , 1991 .

[16]  V. Ponce,et al.  Two-centre effects in ionization by ion impact , 1991 .

[17]  Miraglia,et al.  Quantum-mechanical impulse approximation for single ionization of hydrogenlike atoms by multicharged ions. , 1991, Physical review. A, Atomic, molecular, and optical physics.

[18]  McGuire,et al.  Projectile electron loss with a molecular hydrogen target. , 1991, Physical review. A, Atomic, molecular, and optical physics.

[19]  Olson,et al.  Quantum interference in clothed-ion-atom binary peak structures. , 1991, Physical review letters.

[20]  D. Schultz,et al.  Theoretical description of the binary peak in clothed ion-atom collisions , 1990 .

[21]  A. Petersen,et al.  Two-centre effects in electron emission from the impact of fast multiply charged projectiles on helium , 1990 .

[22]  D. Schultz,et al.  Non-q2 scaling of the ionization cross section near the binary peak , 1990 .

[23]  D. Lee,et al.  Anomalous q dependence of 0' binary encounter electron production in energetic collisions of Fq+ (q=3-9) with He and H2 targets , 1990 .

[24]  D. Lee,et al.  Binary-encounter electrons observed at 0° in collisions of 1-2-MeV/amu H + , C 6+ , N 7+ , O 8+ , and F 9+ ions with H 2 and He targets , 1990 .

[25]  Macek,et al.  Perturbation theory for strongly interacting atomic systems. , 1990, Physical Review A. Atomic, Molecular, and Optical Physics.

[26]  S. Schmidt,et al.  Observation of structures in the binary encounter peak in fast uranium-rare gas collisions , 1989 .

[27]  Olson,et al.  Classical two-center effects in ejected-electron spectra from p+, p-, and He2++He collisions at intermediate energies. , 1989, Physical review. A, General physics.

[28]  N. Stolterfoht,et al.  Evidence for Two-Centre Effects in the Electron Emission from 25 MeV/u Mo40+ + He Collisions: Theory and Experiment , 1987 .

[29]  J. Miraglia,et al.  Ionisation and excitation to Rydberg states in collisions of fully stripped ions with hydrogen atoms , 1987 .

[30]  D. Jakubassa-Amundsen.  Electron emission in asymmetric collisions with fast, heavy projectiles via continuum charge transfer , 1983 .

[31]  W. E. Wilson,et al.  Distributions in Energy and Angle of Electrons Ejected from Molecular Nitrogen by 0.3- to 1.7-MeV Protons , 1971 .

[32]  J. Macek.  Theory of the Forward Peak in the Angular Distribution of Electrons Ejecteed by Fast Protons , 1970 .