Semiempirical method for extracting electron molecule cross sections from experimental data: CF4 as an example

1993 ◽  
Vol 13 (4) ◽  
pp. 655-671 ◽  
Author(s):  
B. Stefanov ◽  
P. Pirgov
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.


1999 ◽  
Vol 14 (03) ◽  
pp. 223-230 ◽  
Author(s):  
O. V. SELYUGIN

A possibility to obtain restrictions of the magnitude of the elastic spin-flip hadron scattering amplitude from accurately measured experimental data on the differential cross-sections of elastic hadron–hadron scattering is shown. Appropriate estimations confirm the previous analysis of experimental data at [Formula: see text] GeV and a probable contribution of the hadron spin-flip amplitude.


2016 ◽  
Vol 104 (8) ◽  
Author(s):  
Junhua Luo ◽  
Chunlei Wu ◽  
Li Jiang ◽  
Long He

Abstract:The cross sections for (n,x) reactions on samarium isotopes were measured at (d-T) neutron energies of 13.5 and 14.8 MeV with the activation technique. Samples were activated along with Nb and Al monitor foils to determine the incident neutron flux. Theoretical calculations of excitation functions were performed using the nuclear model codes TALYS-1.6 and EMPIRE-3.2 Malta with default parameters, at neutron energies varying from the reaction threshold to 20 MeV. The results were discussed and compared with experimental data found in the literature. At neutron energies 13.5 and 14.8 MeV, the cross sections of the


2011 ◽  
Vol 20 (04) ◽  
pp. 953-957 ◽  
Author(s):  
P. HUU-TAI CHAU

An overview of calculations performed within the Continuum Discretized Coupled Channels (CDCC) approach for deuteron induced reactions is given. We briefly present an extension of the CDCC formalism which accounts for the target excitations allowing us to determine ( d , d ') cross sections off deformed nuclei. We compare some calculated inelastic cross sections with experimental data. Then it is shown that the CDCC formalism can also be a useful tool to determine ( d , p ) cross sections. This point is illustrated with 54 Cr ( d , p )55 Cr reactions.


2015 ◽  
Vol 24 (07) ◽  
pp. 1550050 ◽  
Author(s):  
E. Matsinos ◽  
G. Rasche

In a previous paper, we reported the results of a partial-wave analysis (PWA) of the pion–nucleon (πN) differential cross-sections (DCSs) of the CHAOS Collaboration and came to the conclusion that the angular distribution of their π+p data sets is incompatible with the rest of the modern (meson factory) database. The present work, re-addressing this issue, has been instigated by a number of recent improvements in our analysis, namely regarding the inclusion of the theoretical uncertainties when investigating the reproduction of experimental data sets on the basis of a given "theoretical" solution, modifications in the parametrization of the form factors of the proton and of the pion entering the electromagnetic part of the πN amplitude, and the inclusion of the effects of the variation of the σ-meson mass when fitting the ETH model of the πN interaction to the experimental data. The new analysis of the CHAOS DCSs confirms our earlier conclusions and casts doubt on the value for the πN Σ term, which Stahov, Clement and Wagner have extracted from these data.


1990 ◽  
Vol 68 (1) ◽  
pp. 104-110 ◽  
Author(s):  
B. Plenkiewicz ◽  
P. Plenkiewicz ◽  
J.-P. Jay-Gerin

Our earlier pseudopotential calculations on electrons colliding with argon and krypton are extended to consider the elastic electron–helium scattering system. In this paper, we present detailed results for phase shifts, differential, total, and momentum-transfer cross sections for this system for incident electron energies in the range from 0 to 20 eV. These agree very well with existing experimental data and with other theoretical calculations.


2018 ◽  
Vol 194 ◽  
pp. 07002
Author(s):  
M.K. Gaidarov ◽  
V.K. Lukyanov ◽  
D.N. Kadrev ◽  
E.V. Zemlyanaya ◽  
A.N. Antonov ◽  
...  

A microscopic analysis of the optical potentials (OPs) and cross sections of elastic scattering of 8B on 12C, 58Ni, and 208Pb targets at energies 20 < E < 170 MeV and 12,14Be on 12C at 56 MeV/nucleon is carried out. The real part of the OP is calculated by a folding procedure and the imaginary part is obtained on the base of the high-energy approximation (HEA). The density distributions of 8B evaluated within the variational Monte Carlo (VMC) model and the three-cluster model (3CM) are used to construct the potentials. The 14Be densities obtained in the framework of the the generator coordinate method (GCM) are used to calculate the optical potentials, while for the same purpose both the VMC model and GCM densities of 12Be are used. In the hybrid model developed and explored in our previous works, the only free parameters are the depths of the real and imaginary parts of OP obtained by fitting the experimental data. The use of HEA to estimate the imaginary OP at energies just above the Coulomb barrier is discussed. In addition, cluster model, in which 8B consists of a p-halo and the 7Be core, is applied to calculate the breakup cross sections of 8B nucleus on 9Be, 12C, and 197Au targets, as well as momentum distributions of 7Be fragments. A good agreement of the theoretical results with the available experimental data is obtained. It is concluded that the reaction studies performed in this work may provide supplemental information on the internal spatial structure of the proton- and neutron-halo nuclei.


2006 ◽  
Vol 15 (02) ◽  
pp. 387-392 ◽  
Author(s):  
V. A. PLUJKO ◽  
I. M. KADENKO ◽  
O. A. BEZSHYYKO ◽  
L. O. GOLINKA-BEZSHYYKO ◽  
O. I. DAVIDOVSKAYA

Extensive comparisons of E1 strength calculations within framework of the various methods are performed in atomic nuclei near beta-stability line. Photoabsorption cross-sections are calculated and compared with experimental data to test radiative strength function models.


2018 ◽  
pp. 81-89
Author(s):  
Erika Martins de Carvalho ◽  
Roselene Ribeiro Riente ◽  
José Daniel Figueroa Villar

Various complexes of DHA with transition-metal cations are known for their antifungal properties. Here, four novel Zn and Cd complexes were prepared via the substitution of water by pyridine andg-picoline using Zn(DHA)2(H2O)2 (2) and Cd(DHA)2(H2O)2 (3) as starting materials. The products were characterized by IR, UV, elemental analysis, TGA and NMR techniques, including correlation times and intermolecular distance measurements using the NULL pulse sequence. The experimental data were compared to the molecular modeling results using DFT and the semiempirical method PM3, confirming that the pentacoordinated Zn complexes have bipyramidal geometry while the Cd complexes have the expected octahedral geometry. These results show that substitution of Zn by Cd leads to an important modification of the coordination structure, especially when strong ligands are involved.


2018 ◽  
Vol 64 (5) ◽  
pp. 498
Author(s):  
Hocine Aouchiche

Differential and integral cross sections for elastic scattering of electron by NH3 molecule are investigated for the energy ranging from 10 eV to 20 keV.  The calculations are carried out in the framework of partial wave formalism describing the target molecule by means of one center molecular Hartree-Fock functions.  A spherical complex optical potential used includes a static part – obtained here numerically from quantum calculation – and fine effects like correlation, polarization and exchange potentials. The results obtained in this model point out clearly the role played by the exchange and the correlation-polarization contributions in particular at lower scattering angles and lower incident energies. Both differential and integral cross sections obtained are compared with a large set of experimental data available in the literature and well agreement is found throughout the scattering angles and whole energy range investigated here.


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