Experimental evidence of beam-foil convoy electrons being produced by an electron transfer to the continuum mechanism
The origin of beam-foil convoy electrons has been a subject of many controversial interpretations and discussions. In this work, velocity distributions of electrons ejected into the forward direction from a carbon-foil target have been measured with incident proton beams of energies between 60 and 300 keV, and under the same experimental conditions as equivalent measurements recently performed in this laboratory with a He-gas target. Cusp widths are discussed as a function of projectile velocity and instrumental angular acceptance by taking fractional peak heights from the base line as well as by previously subtracting a background obtained by joining peak tails. It is concluded that neither of these procedures is valid. On the other hand, measured electron spectra can be well fitted in terms of a general parametric expression of the scattering amplitude for an electron transfer to the continuum process. The absence of a strong negative cusp skewness, as was observed with the gas target, hints in the direction of an electron loss rather than an electron capture to the continuum process. A significant background contribution that is absent for a single-collision electron transfer to the continuum process is interpreted as due to the emission of secondary electrons that are not correlated to the emerging projectiles.
- Research Organization:
- Centro Atomico Bariloche, Comision Nacional de Energia Atomica, 8400-Bariloche, Argentina and Instituto Balseiro, Comision Nacional de Energia Atomica and Universidad Nacional de Cuyo, 8400-Bariloche, Argentina
- OSTI ID:
- 5675993
- Journal Information:
- Phys. Rev. A; (United States), Vol. 28:2
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CARBON
ION SPECTROSCOPY
ANGULAR DISTRIBUTION
ELECTRON LOSS
ELECTRON TRANSFER
ELECTRONS
EXPERIMENTAL DATA
KEV RANGE 10-100
KEV RANGE 100-1000
NOISE
PROTONS
SECONDARY EMISSION
THIN FILMS
BARYONS
DATA
DISTRIBUTION
ELEMENTARY PARTICLES
ELEMENTS
EMISSION
ENERGY RANGE
FERMIONS
FILMS
HADRONS
INFORMATION
KEV RANGE
LEPTONS
NONMETALS
NUCLEONS
NUMERICAL DATA
SPECTROSCOPY
640304* - Atomic
Molecular & Chemical Physics- Collision Phenomena