Role of Two-Center Electron–Electron Interaction in Projectile Electron Excitation and Loss

Montenegro, E. C.; Meyerhof, W. E.; McGuire, J. H.

doi:10.1016/s1049-250x(08)60079-8

Cited by 88 publications

(85 citation statements)

References 67 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2 at small q and Z 2 + N at large q that has been observed [45,46]. We suggest that for vortex photons such an analysis might be applied to the vortex factor of Eq(10) when λ/z R << 1, since this condition is analogous to Zv 0 /v << 1 that defines the region of validity for use of perturbation theory in ion-atom collisions, where Zv 0 is the speed of the electron about the nucleus of the projectile ion, and v is the speed of the projectile itself.…”

Section: Experimental Considerationsmentioning

confidence: 59%

Atomic form factor for twisted vortex photons interacting with atoms

Guthrey¹,

Kaplan²,

McGuire³

2014

Phys. Rev. A

View full text Add to dashboard Cite

The relatively new atomic form factor for twisted (vortex) beams, which carry orbital angular momentum (OAM), is considered and compared to the conventional atomic form factor for plane wave beams that carry only spin angular momentum (SAM). Since the vortex symmetry of a twisted photon is more complex that that of a plane-wave, evaluation of the atomic form factor is also more complex for twisted photons. On the other hand, the twisted photon has additional parameters, including the OAM quantum number, ℓ, the nodal radial number, p, and the Rayleigh range, z R that determines the cone angle of the vortex. This Rayleigh range may be used as a variable parameter to control, in new ways, the interaction of twisted photons with matter. Here we address: i) normalization of the vortex atomic form factor, ii) displacement of target atoms away from the center of the beam vortex, and iii) formulation of transition probabilities for a variety of photon-atom processes. We attend to features related to new experiments that can test the range of validity and accuracy of calculations of these variations of the atomic form factor. Using the absolute square of the form factor for vortex beams, we introduce a vortex factor that can be directly measured.

show abstract

Section: Experimental Considerationsmentioning

confidence: 59%

Atomic form factor for twisted vortex photons interacting with atoms

Guthrey¹,

Kaplan²,

McGuire³

2014

Phys. Rev. A

View full text Add to dashboard Cite

show abstract

“…Thus, we also neglect the so-called antiscreening effect, where the electron-electron interaction between the bound projectile electrons and the target electrons results in an enhancement of the ionization and excitation cross sections at intermediate to high energies. [32][33][34] Nevertheless, at these energies, the projectile-charge state is generally about the projectile atomic number and, consequently, the antiscreening effect is of minor importance for energy loss calculations. A comparison of the present model with other calculations is shown in Figs.…”

Section: ͑10͒mentioning

confidence: 99%

Random and channeling stopping powers of He and Li ions in Si

et al. 2002

View full text Add to dashboard Cite

In this work we have measured the electronic stopping powers of 4 He and 7 Li ions for channeling and random directions in Si as a function of the incident ion energy. The channeling (͗100͘ for Li, ͗110͘ and ͗111͘for Li and He͒ and the random ͑Li only͒ measurements cover a wide energy range between 200 keV and 9 MeV. The Rutherford backscattering technique together with different multilayer targets has been employed in the present experiments. The results are compared to calculations carried out in the framework of the unitary convolution approximation, which takes into account the impact-parameter-dependent energy loss for each projectile charge state, with further refinements including screening effects in close collisions between the electrons of the target and the screened projectile.

show abstract

“…This threshold, however, is partially diffused by the rather broad electron momentum distribution due to its orbital motion around the target. Today, this process is well understood within the electron scattering model [2][3][4][5] and the Born approximation [6,7] and is found to be important in excitation [1,[7][8][9] and ionization [10][11][12][13] processes in ion-atom collisions [14][15][16]. It is particularly prevalent in ion collisions with low-Z targets, where competition from excitation due to the target-nucleus charge is relatively smaller [16].…”

Section: Introduction -The 1s2s2p 4 P Transfer-loss Puzzlementioning

confidence: 99%

Production of 1s2s2p4P states by transfer-loss cascades in O5+ collisions with he and H2 targets

Zouros¹,

Sulik²,

Gulyás³

et al. 2006

Braz. J. Phys.

View full text Add to dashboard Cite

Single differential cross-sections for transfer-loss (TL) leading to the production of O 5+ (1s2s 3 S)nl 4 L states were computed for 0.2-1.2 MeV/u collisions of O 5+ (1s 2 2s) ions with He and H 2 targets. At these collision energies, 1s loss is significant and electron transfer to n = 3 − 4 levels is dominant. Furthermore, due to spin conservation, quartet states can only be populated by TL. Within the independent particle model (IPM), the probability of 1s electron loss from O 5+ (1s 2 2s) projectiles was calculated using the semi-classical approach, while the probability for electron transfer to the O 5+ (1s2s 3 S)nl 4 L states (n ≥ 2) was computed using the continuum distorted wave (CDW) approximation. The majority of states with n > 2 can be assumed to have sufficient time to eventually decay with an almost 100% probability to the long-living metastable 1s2s2p 4 P level via a much faster sequence of electric dipole transitions, thus establishing an upper limit to such cascade contributions. The inclusion of this cascade feeding is found to lead to a strong enhancement in the production of the 1s2s2p 4 P states, particularly for collisions with the H 2 target, thus reducing dramatically the existing two-order of magnitude discrepancy between older TL calculations (for n = 2 only) and existing zero-degree Auger projectile electron spectroscopy measurements.

show abstract

Role of Two-Center Electron–Electron Interaction in Projectile Electron Excitation and Loss

Cited by 88 publications

References 67 publications

Atomic form factor for twisted vortex photons interacting with atoms

Atomic form factor for twisted vortex photons interacting with atoms

Random and channeling stopping powers of He and Li ions in Si

Production of 1s2s2p4P states by transfer-loss cascades in O5+ collisions with he and H2 targets

Contact Info

Product

Resources

About