Continuous Ultraviolet Absorption BY Si+(4Pe): an Exploratory R-Matrix Calculation

1988 ◽  
Vol 102 ◽  
pp. 185-188
Author(s):  
J.A. Tully

AbstractThe R-matrix method is used to calculate photoionisation from the first excited state 3s3p23Pe of Si+. The lowest two triplet terms 3s3p3Poand 3p23Peof the residual ion Si++are included in the calculation. They are approximated by configuration interaction wavefunctions which are constructed from six spectroscopic orbitals: 1s,2s,2p,3s,3p,3d. Partial and total cross-sections are tabulated for photon energies ranging from threshold (705 A) up to 2.5 Ryd (365 A). Some of the 3p2np autoionising resonances are delineated and shown graphically.

2006 ◽  
Vol 84 (8) ◽  
pp. 707-715 ◽  
Author(s):  
AK S Jha ◽  
N Singh ◽  
N Verma ◽  
M Mohan

The close-coupling R-matrix method has been used to calculate photoionization cross sections for the ground and the lowest three excited states using the relativistic Breit–Pauli approximation. Configuration interaction wave-functions are used to represent eleven lowest LSJ target states of Si VI retained in the R-matrix expansion. Relativistic effects are clearly revealed from resonance converging on the excited states of Si VI.PACS No.: 32.80.Fb


Atoms ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 47
Author(s):  
Kathryn R. Hamilton ◽  
Klaus Bartschat ◽  
Oleg Zatsarinny

We have applied the full-relativistic Dirac B-Spline R-matrix method to obtain cross sections for electron scattering from ytterbium atoms. The results are compared with those obtained from a semi-relativistic (Breit-Pauli) model-potential approach and the few available experimental data.


2012 ◽  
Vol 86 (6) ◽  
Author(s):  
S. MacMullin ◽  
M. Boswell ◽  
M. Devlin ◽  
S. R. Elliott ◽  
N. Fotiades ◽  
...  

1984 ◽  
Vol 37 (3) ◽  
pp. 267 ◽  
Author(s):  
FC Barker

The E1 decay strength of the t + first excited state of 9Be is calculated using R-matrix formulae in which the excited state is correctly treated as unbound. Agreement with experiment is obtained for a reasonable choice of channel radius.


2019 ◽  
Vol 11 ◽  
Author(s):  
G. Kalliabakos ◽  
S. Kossionides ◽  
P. Misailides ◽  
C. T. Papadopoulos ◽  
R. Vlastou

A combination of nuclear reaction analysis (NRA) and Rutherford backscattering spectroscopy (RBS) were utilized in order to obtain information on the depth distribution of sulphur and copper in artificially produced and natural patina layers. The copper profiling was performed by using the reaction 63Cu(p,p'y)6 3Cu and detecting the 1327 keV γ-ray deexciting the third excited state to the ground state of 6 3Cu produced. For the determination of sulfur the 2230 keV γ-ray was used, deexciting the first excited state to the ground state of 32S formed through the reaction 3 2S(p,p'y)3 2S, which exhibits three sharp resonances at projectile energies 3.094, 3.195 and 3.379 MeV. The relevant cross-sections were measured in the energy range between 3.0 and 3.7 MeV in steps of 20 keV at 125° to the incident proton beam direction. Supporting information on the depth distribution of oxygen and the other elements of the patina samples was obtained by p-RBS (Ep = 1.5 MeV; θ = 160°).


Atoms ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 51
Author(s):  
Oleg Zatsarinny ◽  
Swaraj Tayal

Partial and total photoionization cross sections of iron-peak elements are important for the determination of abundances in late-type stars and nebular objects. We have investigated photoionization of neutral chromium from the ground and excited states in the low energy region from the first ionization threshold at 6.77 eV to 30 eV. Accurate descriptions of the initial bound states of Cr I and the final residual Cr II ionic states have been obtained in the multiconfiguration Hartree-Fock method together with adjustable configuration expansions and term-dependent non-orthogonal orbitals. The B-spline R-matrix method has been used for the calculation of photoionization cross sections. The 194 LS final ionic states of Cr II 3d44s, 3d34s2, 3d5, 3d44p, and 3d34s4p principal configurations have been included in the close-coupling expansion. The inclusion of all terms of these configurations has significant impact on the near-threshold resonance structures as well as on the nonresonant background cross sections. Total photoionization cross sections from the ground 3d54sa7S and excited 3d54sa5S, 3d44s2a5D, 3d54pz5P, and 3d44s4py5P states of Cr I have been compared with other available R-matrix calculation to estimate the likely uncertainties in photoionization cross sections. We analyzed the partial photoionization cross sections for leaving the residual ion in various states to identify the important scattering channels, and noted that 3d electron ionization channel becomes dominant at higher energies.


Sign in / Sign up

Export Citation Format

Share Document