Hyperspherical approach to double-electron excitation of He by fast-ion impact. II. Excitation to the (2 l 3 l prime ) and (3 l 3 l prime ) manifolds by proton and antiproton impact

Journal Article · Mon Jun 01 00:00:00 EDT 1992 · Physical Review A. General Physics; (United States)

DOI:https://doi.org/10.1103/PhysRevA.45.7922· OSTI ID:7183090

Moribayashi, K; Hino, K; Matsuzawa, M ^[1]; Kimura, M ^[2]

---

1. Department of Applied Physics and Chemistry, The University of Electro-Communications, 1-5-1 Chofu-ga-oka Chofu-shi, Tokyo 182 (Japan)
2. Argonne National Laboratory, Argonne, Illinois 60439 (United States) Department of Physics, Rice University, Houston, Texas 77251 (United States)

Double-electron excitation process of He atoms from the ground state to the manifolds of the doubly excited 2{ital l}3{ital l}{prime} and 3{ital l}3{ital l}{prime} states by proton and antiproton impact have been theoretically investigated using a close-coupling method at the 1.5-MeV/{ital u} energy regime. The semiclassical impact-parameter method with a straight-line-trajectory approximation is employed to describe collision processes. Hyperspherical wave functions are adopted to take full account of strongly correlated motion of two atomic electrons in He. The difference between the cross section by proton impact and that by antiproton impact is small except for the process to the 3{ital p}3{ital p} {sup 1}{ital S{ital e}} state. The reason for the small difference between {sigma}({ital p}) and {sigma}({ital {bar p}}) is discussed. The {sup 1}{ital P0} states are found to play an important role as intermediate ones. For the process to the doubly excited 2{ital l}3{ital l}{prime} states, the (2{ital s}3{ital p}+3{ital s}2{ital p}){sup 1}{ital P0} state plays a crucial role. For the excitation process to the 3{ital l}3{ital l}{prime} states, the ratio of the second-order process to the first-order one is larger than that in the case of the process to the 2{ital l}2{ital l}{prime} and 2{ital l}3{ital l}{prime} states, suggesting that the difference between the mechanism of the excitation to the (2{ital l},2{ital l}{prime}) and (2{ital l},3{ital l}{prime}) manifolds and that to the (3{ital l},3{ital l}{prime}) manifold arises from the smaller overlap of the (3{ital l},3{ital l}{prime}) wave functions with that of the ground state. It is seen that the physical interpretation of the results based on the rovibrator model of the doubly excited states gives a deeper physical insight into the mechanism of the double-electron excitation.

• DOE Contract Number: W-31-109-ENG-38
• OSTI ID: 7183090
• Journal Information: Physical Review A. General Physics; (United States), Vol. 45:11; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ANTIPROTONS
ION-ATOM COLLISIONS
HELIUM
PROTONS
CHARGE STATE
CROSS SECTIONS
EXCITATION
GROUND STATES
MEV RANGE
TWO-BODY PROBLEM
ANTIBARYONS
ANTIMATTER
ANTINUCLEI
ANTINUCLEONS
ANTIPARTICLES
ATOM COLLISIONS
BARYONS
COLLISIONS
ELEMENTARY PARTICLES
ELEMENTS
ENERGY LEVELS
ENERGY RANGE
ENERGY-LEVEL TRANSITIONS
FERMIONS
FLUIDS
GASES
HADRONS
ION COLLISIONS
MANY-BODY PROBLEM
MATTER
NONMETALS
NUCLEI
NUCLEONS
RARE GASES
664300* - Atomic & Molecular Physics- Collision Phenomena- (1992-)