The effect of dynamical screening on helium (e, 3e) differential cross-sections

Götz, J.; Walter, Michael; Briggs, J S

doi:10.1088/0953-4075/38/10/014

Cited by 20 publications

(17 citation statements)

References 39 publications

(47 reference statements)

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“…Furthermore, in most collisions the projectile scattering angles and, therefore, the momentum transfers are small, and the cross sections very closely resemble these observed in double photoionization of helium being governed by the dipole selection rules. For these reasons, various few-body Coulomb methods [16,17] or the convergent close coupling (CCC) method in combination with the first [18] or second Born approximation [19] were in good agreement with the experimental data on a relative scale.…”

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confidence: 82%

(e,3e)on Helium at Low Impact Energy: The Strongly Correlated Three-Electron Continuum

et al. 2007

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Double ionization of the helium atom by slow electron impact (E(0)=106 eV) is studied in a kinematically complete experiment. Because of a low excess energy E(exc)=27 eV above the double ionization threshold, a strongly correlated three-electron continuum is realized. This is demonstrated by measuring and calculating the fully differential cross sections for equal energy sharing of the final-state electrons. While the electron emission is dominated by a strong Coulomb repulsion, also signatures of more complex dynamics of the full four-body system are identified.

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confidence: 82%

(e,3e)on Helium at Low Impact Energy: The Strongly Correlated Three-Electron Continuum

et al. 2007

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“…Such processes are described by rigorously established integral equations in momentum space [1] and configuration-space methods, more convenient for calculations, are well established [2][3][4][5]. Some researchers [6][7][8][9], perhaps emboldened by successes in numerical treatments of collisions involving three charged particles in continuum states, have turned their attention to the e → 3e reaction; double ionization of helium provides the simplest example. The theoretical basis for such calculations is rather less firm than it is for single ionization.…”

Section: Introductionmentioning

confidence: 99%

General time-independent theory of ionization and breakup reactions

Rosenberg¹

2008

J. Phys. B: At. Mol. Opt. Phys.

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A rigorous formulation of non-relativistic time-dependent multiparticle collision theory was developed some time ago, in which the effect of long-range Coulomb forces was accounted for by a modification of the standard wave operator that appears in treatments of neutral-particle scattering. This theory is here converted to a time-independent form, with the wave-operator modification replaced by the use of Coulomb-modified plane waves in the construction of the wave packets that appear in the theory. This provides a convenient basis for the development of approximation techniques in configuration space, including the use of variational methods of calculation, based on integral identities for the transition amplitudes. In many cases oscillatory divergences appear in the integrals representing the ionization or breakup amplitudes. A method for removing such divergences by an averaging of the integrand at great distances is defined.

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“…This is based on the realization that the three-body screening effects are not represented in the 3C wave function [10]. One of the simplest ways is the replacement of the fixed charges of the particles by dynamically screened effective charges depending upon the relative coordinates or momenta of the outgoing particles, known as the dynamically screened 3C (DS3C) approximation [11].…”

Section: Introductionmentioning

confidence: 99%

Two-electron cusp in the double ionization of helium

et al. 2010

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We analyze the double ionization of He under the impact of 100 keV He 2+ projectiles. The process is described within the framework of the impact parameter and frozen-correlation approximations where the one-electron events are treated by the continuum distorted wave method. Correlation between the emitted electrons, which plays an important role in forming the shape of the differential distribution of the electron emission, is described by the Coulomb density of states approximation (CDS). Special attention is paid to the region of the two-electron cusp that has been observed in a recent experiment for 100 keV He 0 + He collisions [L. Sarkadi and A. Orbán, Phys. Rev. Lett. 100, 133201 (2008)]. In the cusp region the correlated motion of the two electrons is influenced dominantly by the outgoing projectile, that is, the correlation function of the CDS treatment is expected to depend on the electron momenta measured relative to the projectile rather than to the target nucleus. A qualitative agreement with the experiment is achieved with a CDS model based on the use of such a projectile-centered correlation function that applies effective charges as given in the dynamically screened three-Coulomb wave function.

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The effect of dynamical screening on helium (e, 3e) differential cross-sections

Cited by 20 publications

References 39 publications

(e,3e)on Helium at Low Impact Energy: The Strongly Correlated Three-Electron Continuum

(e,3e)on Helium at Low Impact Energy: The Strongly Correlated Three-Electron Continuum

General time-independent theory of ionization and breakup reactions

Two-electron cusp in the double ionization of helium

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