scholarly journals How to Explain the Difference between (?, e) and (e, 2e) Spectroscopic Factors

1991 ◽  
Vol 44 (3) ◽  
pp. 293 ◽  
Author(s):  
M Ya Amusia ◽  
AS Kheifets
Keyword(s):  
Atomic State ◽  
Final States ◽  
Electron Correlations ◽  
Atomic Shell ◽  
Initial State ◽  
Electron Momentum ◽  
Relative Line ◽  
Spectroscopic Factors ◽  
Electron Momentum Spectroscopy ◽  
The Difference

It is shown that the relative line intensity of the main and satellite lines in the atomic shell ionisation spectrum depends significantly on the mechanism responsible for the removal of the electron. This dependence is explained by the influence of many-electron correlations in the initial state of the atom to be ionised, which is considerable when the momentum transferred to the ion is large. This is the case for photoionisation, i.e. the (y, e) reaction under the condition of large photon energy. On the contrary, in electron momentum spectroscopy, such as the symmetric noncoplanar (e, 2e) reaction, the momentum transferred to the ion is typically small and the initial atomic state correlations are negligible. It follows from this that the spectroscopic factors of the different final states of the ion, as defined in the usual way, can be measured only for the (e,2e) reaction, whereas a more involved interpretation is necessary for the (y, e) reaction. Comparison of the calculated spectroscopic factors of Ar II and Xe II 2S ion eigenstates with recent (Y,e) and (e,2e) experimental data has confirmed this conclusion.

scholarly journals Electron Momentum Spectroscopy

1986 ◽  
Vol 39 (5) ◽  
pp. 587 ◽  
Author(s):  
IE McCarthy
Keyword(s):  
Impulse Approximation ◽  
High Electron ◽  
Final States ◽  
Final State ◽  
Structure Information ◽  
Plane Wave Impulse Approximation ◽  
Ion Structure ◽  
Spectroscopic Factors ◽  
Electron Momentum Spectroscopy ◽  
Energy And Momentum

For sufficiently high electron energies (greater than a few hundred eV) and sufficiently low recoil momenta Oess than a few atomic units) the differential cross section for the non-coplanar symmetric (e,2e) reaction on an atom or molecule depends on the target and ion structure only through the target-ion overlap. Experimental criteria for the energy and momentum are that the apparent structure information does not change when the energy and momentum are varied. The plane-wave impulse approximation is a sufficient description of the reaction mechanism for determining spherically averaged squares of momentum-space orbitals for atoms and molecules and for coefficients describing initial- and final-state correlations. For mainly uncorrelated initial states, spectroscopic factors for final states belonging to the same manifold are uniquely determined. For molecules, summed spectroscopic factors can be compared for different ion manifolds. For atoms, summed spectroscopic factors and higher-momentum profiles require the dist~rted-wave impulse approximation.

Electron momentum spectroscopy ofH2andD2: Ionization to ground and excited final states

1997 ◽  
Vol 56 (2) ◽  
pp. 1393-1402 ◽  
Author(s):  
N. Lermer ◽  
B. R. Todd ◽  
N. M. Cann ◽  
Y. Zheng ◽  
C. E. Brion ◽  
...  
Keyword(s):  
Final States ◽  
Electron Momentum ◽  
Electron Momentum Spectroscopy

Recent Advances in Electron Momentum Spectroscopy

1993 ◽  
Vol 48 (1-2) ◽  
pp. 371-389
Author(s):  
Erich Weigold
Keyword(s):  
Excited State ◽  
Valence Electron ◽  
Condensed Matter ◽  
Momentum Density ◽  
Initial State ◽  
Electron Momentum ◽  
Hartree Fock ◽  
Electron Momentum Spectroscopy ◽  
Momentum Distributions ◽  
D Wave

Abstract The flexibility of the (e, 2e) technique or "electron momentum spectroscopy" (EMS) in obtaining information on the electronic structure of atoms, molecules, and solids is demonstrated. High-resolution EMS measurements for argon, including the first measurements of momentum profiles belonging to the 2P0 and 2De -manifolds, are used to demonstrate the technique for atomic targets. The d-wave transitions in argon are entirely due to initial-state correlations. The first (e, 2e) measurements on an excited target, and also on an oriented target, are discussed. Sodium atoms are pumped to the ml = +1 state of the excited 3p-state by σ+ -light from a laser. The (e, 2e) measurements on this excited state are in excellent agreement with the momentum density given by the 3p (ml - 1) Hartree-Fock wavefunction. The recent measurements of the valence-electron momentum distributions for ethyne, as well as some earlier results for water, are used as an example of the application of EMS to the study of molecules. The application of the EMS technique to measure spectral momentum densities in condensed-matter targets is demonstrated by some recent results on amorphous carbon.

Electron momentum spectroscopy of atoms, molecules, and thin films

1999 ◽  
Vol 169 (10) ◽  
pp. 1111 ◽  
Author(s):  
Vladimir G. Neudachin ◽  
Yurii V. Popov ◽  
Yurii F. Smirnov
Keyword(s):  
Thin Films ◽  
Electron Momentum ◽  
Electron Momentum Spectroscopy

Electron momentum spectroscopy of N2O

2003 ◽  
Vol 133 (1-3) ◽  
pp. 113-121 ◽  
Author(s):  
Y. Khajuria ◽  
M. Takahashi ◽  
Y. Udagawa
Keyword(s):  
Electron Momentum ◽  
Electron Momentum Spectroscopy

The electronic structure of different forms of solid carbon studied by electron momentum spectroscopy

1998 ◽  
Vol 87 (3) ◽  
pp. 231-251 ◽  
Author(s):  
M. Vos ◽  
A. Kheifets ◽  
E. Weigold ◽  
S.A. Canney ◽  
F.F. Kurp
Keyword(s):  
Electronic Structure ◽  
Solid Carbon ◽  
Electron Momentum ◽  
Electron Momentum Spectroscopy

An electron momentum spectroscopy study of the highest occupied molecular orbital of difluoromethane

2004 ◽  
Vol 390 (1-3) ◽  
pp. 162-165 ◽  
Author(s):  
G.L. Su ◽  
C.G. Ning ◽  
S.F. Zhang ◽  
X.G. Ren ◽  
H. Zhou ◽  
...  
Keyword(s):  
Molecular Orbital ◽  
Spectroscopy Study ◽  
Electron Momentum ◽  
Highest Occupied Molecular Orbital ◽  
Electron Momentum Spectroscopy

Electron-Momentum Spectroscopy of Solids by the (e,2e) Reaction

1997 ◽  
pp. 249-259
Author(s):  
A. S. Kheifets ◽  
M. Vos ◽  
S. A. Canney ◽  
X. Guo ◽  
I. E. McCarthy ◽  
...  
Keyword(s):  
Electron Momentum ◽  
Electron Momentum Spectroscopy

Sensitive observations of orbital electron density image by electron momentum spectroscopy with different impact energies

2005 ◽  
Vol 404 (4-6) ◽  
pp. 279-283 ◽  
Author(s):  
X.G. Ren ◽  
C.G. Ning ◽  
J.K. Deng ◽  
S.F. Zhang ◽  
G.L. Su ◽  
...  
Keyword(s):  
Electron Density ◽  
Electron Momentum ◽  
Electron Momentum Spectroscopy ◽  
Orbital Electron ◽  
Density Image ◽  
Impact Energies
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