Ne ionization induced by the impact of 106-keV/u H[sup +] and [sup 3]He[sup 2+]: Two-center effects on the soft-electron emission

Journal Article · Wed Dec 01 00:00:00 EST 1993 · Physical Review A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.48.4339· OSTI ID:5798348

Suarez, S; Garibotti, C; Bernardi, G; Focke, P; Meckbach, W ^[1]

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1. Centro Atomico Bariloche e Instituto Balseiro, Comision Nacional de Energia Atomica y Universidad Nacional de Cuyo, 8400 San Carlos de Bariloche, Rio Negro (Argentina)

We present an experimental study of the electron emission induced by the collisional ionization of Ne gas by 106-keV/u H[sup +] and [sup 3]He[sup 2+] projectiles. Cross sections, doubly differential in electron energy [ital E][sub [ital e]] and angle [theta], were measured throughout the ranges 0.5[le][ital E][sub [ital e]][le]440 eV and 0[degree][le][theta][le]180[degree]. We show that measurements at electron energies down to 0.5 eV were possible after a reduction of the physical extension of the gas target to a minimum. We find a remarkable dependence of the measured distribution of soft electrons with the extension of the target. We try a model according to which this effect is attributed to the scattering of electrons into the acceptance cone defined by the detector. Our measurements enable us to perform a quantitative analysis of the shape of the soft-electron peak. Contrary to current belief, this peak is found to be strongly asymmetric. The magnitude of this asymmetry is comparable to that of the cusp resulting from electron capture into the continuum. This puts into evidence that, also for these low-energy electrons, the interaction with the two Coulomb centers, projectile and residual target ion, is essential. By analyzing the ratio of the emission obtained with [sup 3]He[sup 2+] and H[sup +], we also study the dependence of the doubly differential cross section on the projectile charge.

• OSTI ID: 5798348
• Journal Information: Physical Review A; (United States), Vol. 48:6; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
HELIUM IONS
ION-ATOM COLLISIONS
HYDROGEN IONS 1 PLUS
NEON
IONIZATION
ANGULAR DISTRIBUTION
CATIONS
DIFFERENTIAL CROSS SECTIONS
ELECTRON EMISSION
ENERGY SPECTRA
HELIUM 3
KEV RANGE 100-1000
PROTONS
ATOM COLLISIONS
BARYONS
CHARGED PARTICLES
COLLISIONS
CROSS SECTIONS
DISTRIBUTION
ELEMENTARY PARTICLES
ELEMENTS
EMISSION
ENERGY RANGE
EVEN-ODD NUCLEI
FERMIONS
FLUIDS
GASES
HADRONS
HELIUM ISOTOPES
HYDROGEN IONS
ION COLLISIONS
IONS
ISOTOPES
KEV RANGE
LIGHT NUCLEI
NONMETALS
NUCLEI
NUCLEONS
RARE GASES
SPECTRA
STABLE ISOTOPES
664300* - Atomic & Molecular Physics- Collision Phenomena- (1992-)