scholarly journals Probing Electronic Wave Functions of Sodium-Doped Clusters: Dyson Orbitals, Anisotropy Parameters, and Ionization Cross-Sections

2016 ◽  
Vol 120 (49) ◽  
pp. 9841-9856 ◽  
Author(s):  
Anastasia O. Gunina ◽  
Anna I. Krylov
Keyword(s):  
Cross Sections ◽  
Wave Functions ◽  
Ionization Cross ◽  
Electronic Wave ◽  
Anisotropy Parameters ◽  
Electronic Wave Functions ◽  
Doped Clusters ◽  
Ionization Cross Sections

A comparison of theory and experiment for photo-ionization cross-sections I. Neon and the elements from boron to neon

1951 ◽  
Vol 208 (1094) ◽  
pp. 408-418 ◽  
Keyword(s):  
Cross Sections ◽  
General Trend ◽  
Wave Functions ◽  
Ionization Cross ◽  
Hartree Fock ◽  
Quantal Theory ◽  
Ionization Cross Sections ◽  
Photo Ionization ◽  
Near Future ◽  
Dipole Length

The quantal theory of the continuous photo-electric absorption of radiation is briefly summarized, pàrticular attention being given to the alternative formulae available and to the accuracy to be expected in practical calculations. Detailed calculations are described for the photo-ionization cross-section of neon, a system for which it is understood that experimental data should be available in the near future. The calculation is made using Hartree-Fock wave functions and the two formulae of the dipole length and the dipole velocity. The corresponding cross-sections are found to be 5.8 and 4.4 x 10- 18 cm 2 . at the spectral head and to rise slowly with increasing frequency until a broad maximum is reached for an energy of the ejected electron of about 11 eV. A comparison is made with previous calculations on the elements from boron to neon ; the general trend of the results is discussed and improved estimates for boron and fluorine are given (10 x 10 -18 cm 2 . for boron and 4.3 x 10- 18 cm 2 . for fluorine at the spectral head).

LIGHT ION-INDUCED L-SHELL IONIZATION OF HIGH-Z ELEMENTS

1996 ◽  
Vol 06 (01n02) ◽  
pp. 39-50 ◽  
Author(s):  
E. PERILLO ◽  
P. CUZZOCREA ◽  
N. DE CESARE ◽  
G. SPADACCINI ◽  
M. VIGILANTE
Keyword(s):  
Cross Sections ◽  
Production Cross ◽  
Wave Functions ◽  
Ionization Cross ◽  
X Ray ◽  
Li Ion ◽  
Ion Impact ◽  
Ionization Cross Sections ◽  
Coupled Channel ◽  
Shell Ionization

L-shell X-ray production cross sections for selected heavy elements (Tl, Pb, Bi), of interest in BIO-PIXE analyses, have been measured by proton and 7 Li ion impact in the energy range 0.8–2.6 MeV and 1.8–3.3 MeV respectively. Further, production cross sections for 7 Li ion impact on Au between 1.0 and 2.4 MeV have been measured. L-subshell ionization cross sections have been extracted and arranged, together with similar results from other laboratories, in an analysis aiming at testing the performance of various theoretical approximations in the description of the ionization process. The disagreement observed at low values of the reduced velocity parameter ξ R L between the data and the predictions of the ECPSSR model is significantly reduced by using a United Atom approximation in the treatment of the binding correction, suggested by our group (ECPSSR-UA). The remaining discrepancies, mostly for the L 1-subshell, are almost completely removed by replacing the screened hydrogenlike wave functions with the more realistic Dirac-Hartree-Slater ones. In the case of 7 Li ions, especially for L 2-subshell, also a more refined Coulomb deflection correction and more sophisticated coupled channel calculations are needed.

Convergence of energy-differential ionization cross sections obtained from aT-matrix approach withR-matrix wave functions

2002 ◽  
Vol 65 (6) ◽  
Author(s):  
K. Bartschat ◽  
M. P. Scott ◽  
P. G. Burke ◽  
T. Stitt ◽  
N. S. Scott ◽  
...  
Keyword(s):  
Cross Sections ◽  
Wave Functions ◽  
Matrix Approach ◽  
Ionization Cross ◽  
Ionization Cross Sections

Electron Ionization Cross Sections for Atomic Subshells

2003 ◽  
Vol 9 (1) ◽  
pp. 42-53 ◽  
Author(s):  
Peter Rez
Keyword(s):  
Cross Sections ◽  
Wave Functions ◽  
Mathematical Form ◽  
Atomic Shell ◽  
Ionization Cross ◽  
X Ray ◽  
High Energies ◽  
Low Energies ◽  
Ionization Cross Sections ◽  
Selection Of

Ionization of atoms is the first step in many analytical procedures. The cross section for ionizing a particular atomic shell is essential for calculating the magnitude of analytical signals. Calculations using atomic wave functions for various shells of all elements relevant for X-ray microanalysis over a range of electron energies up to 400 keV were performed. The calculations for high energies above threshold can be considerably simplified by using the mathematical form of the Bethe ridge that dominates the scattering in this region. Corrections for exchange at low energies above threshold are incorporated in these calculations. A selection of results showing the effects of different approximations on ionization cross sections for K, L, and M shells is presented.

A comparison of theory and experiment for photo-ionization cross-sections II. Sodium and the alkali metals

1951 ◽  
Vol 208 (1094) ◽  
pp. 418-430 ◽  
Keyword(s):  
Cross Sections ◽  
Alkali Metals ◽  
Line Strength ◽  
Wave Functions ◽  
Experimental Results ◽  
Ionization Cross ◽  
Sum Rule ◽  
The Cross ◽  
Ionization Cross Sections ◽  
Photo Ionization

A summary is given of the results of experimental determinations of the atomic photo-ionization cross-sections of the alkali metals. Detailed calculations on sodium are described, using Hartree-Fock wave functions, and it is shown that the theory is capable of reproducing the main features of the experimental results. A comparison with line-strength calculations is made, and the applicability of sum-rule tests is discussed. The finite minimum which is found experimentally in the cross-sections of certain of the alkali metals is attributed to spin-orbit perturbations of the free-electron wave functions. For caesium and rubidium the theoretical calculation based on this effect is shown to give minima of a magnitude comparable to those of the experimental results. The accuracy of previous calculations on the cross-sections of Ca ll is discussed, use being made of sum-rule tests.

EXCITATION AND IONIZATION CROSS SECTIONS FOR HE I FROM NORMALIZED BORN AND K-MATRIX CALCULATIONS: ΔS = 0 TRANSITIONS FROM n = 2, 3 EXCITED STATES

2000 ◽  
Vol 74 (1) ◽  
pp. 123-153 ◽  
Author(s):  
I.L. Beigman ◽  
L.A. Vainshtein ◽  
M. Brix ◽  
A. Pospieszczyk ◽  
I. Bray ◽  
...  
Keyword(s):  
Excited States ◽  
Cross Sections ◽  
Ionization Cross ◽  
Ionization Cross Sections ◽  
K Matrix

Differential transfer ionization cross sections for 50–175-keV proton-helium collisions

1994 ◽  
Vol 50 (1) ◽  
pp. 337-342 ◽  
Author(s):  
S. W. Bross ◽  
S. M. Bonham ◽  
A. D. Gaus ◽  
J. L. Peacher ◽  
T. Vajnai ◽  
...  
Keyword(s):  
Cross Sections ◽  
Ionization Cross ◽  
Transfer Ionization ◽  
Ionization Cross Sections
Sign in / Sign up

Export Citation Format

Share Document