Direct Photodisintegration of 9Be in the Low and Sub-Giant Resonance Energy Region

1969 ◽  
Vol 24 (8) ◽  
pp. 1188-1195
Author(s):  
Terje Aurdal
Keyword(s):  
Cross Sections ◽  
Giant Resonance ◽  
Resonance Energy ◽  
Wave Functions ◽  
Nuclear Model ◽  
Final States ◽  
Core State ◽  
Radial Wave ◽  
Total Cross Sections ◽  
Reaction Channels

Abstract Photodisintegration cross sections for the reaction 9Be(γ,n) 8Be with photonenergies varied from threshold to about 17 MeV are calculated. As nuclear model is assumed a single particle shell model where the valence neutron outside the 8Be core is feeling a spherical field. The core state is assumed to be a mixture of the ground (0+) and the first excited (2+) state of the 8Be nucleus. The total cross sections are splitted up according to the different contributing reaction channels. The radial wave functions in initial as well as final states are of the Saxon-Woods type.

scholarly journals On the quenching of Gamow–Teller strength

1987 ◽  
Vol 65 (6) ◽  
pp. 574-577 ◽  
Author(s):  
J. Rapaport
Keyword(s):  
Cross Sections ◽  
Wave Functions ◽  
Light Nuclei ◽  
Final States ◽  
Excitation Energies ◽  
Intermediate Energies ◽  
Quenching Factor ◽  
Configuration Mixing ◽  
Gamow Teller ◽  
Model Strength

The (p, n) reaction at intermediate energies has been used to measure differential cross sections in light nuclei to final states characterized with a ΔJπ = 1+ transfer (Gamow–Teller (GT) states). Experimental ft values for allowed beta-decay transitions in these nuclei are used to normalize the strength of the GT transitions in units of B(GT). This experimental GT strength is compared with predicted shell–model strength. For p-shell nuclei, the calculated excitation energies of the GT strength using Cohen and Kurath wave functions are in general agreement with the empirical GT distribution. Up to an excitation energy of about 20 MeV, the total experimental and calculated GT strengths are used to obtain the quenching factor, QF = Σ B(GT)exp/Σ B(GT)theor. It is found that QF decreases as the shell gets filled-up. The lowest value seems to occur for single-hole nuclei. This decrease may be explained by configuration mixing not specifically included in the calculations.

Stueckelberg-Landau-Zener-(SLZ)-Modell für atomare Stoßprozesse / Stueckelberg-Landau-Zener-(SLZ) Model for Atomic Scattering Processes

1973 ◽  
Vol 28 (10) ◽  
pp. 1642-1653
Author(s):  
G.-P. Raabe
Keyword(s):  
Cross Sections ◽  
Differential Cross ◽  
Wave Functions ◽  
Differential Cross Sections ◽  
Rare Gases ◽  
Radial Wave ◽  
Atomic Scattering ◽  
The Cross

Scattering processes of atoms, molecules and ions with two crossing electronic potentials may be treated in the Stueckelberg-Landau-Zener-(SLZ) model. In this paper the WKB-solutions for the radial wave functions, given by Stueckelberg are used to calculate differential cross sections. The effects on the cross sections are explained in a semiclassical picture, following the procedures of Ford and Wheeler, and Berry. In the scattering of H+ by rare gases, some effects in the elastic cross sections are observed which can be explained by the influence of the potential of the chargeexchanged particles, using the SLZ-model. The structure in the elastic cross sections for H2+-Kr can be explained as a rainbow structure with superimposed Stueckelberg oscillations.

scholarly journals Direct Photodisintegration of 13C below 17 MeV. Reaction 13C(γ,n) 12C

1969 ◽  
Vol 24 (9) ◽  
pp. 1361-1364 ◽  
Author(s):  
Terje Aurdal
Keyword(s):  
Cross Sections ◽  
Single Particle ◽  
Giant Dipole Resonance ◽  
Valence Neutron ◽  
Nuclear Model ◽  
Final States ◽  
Dipole Resonance

A nuclear model where the single-particle states of the valence neutron are vector coupled to the ground (0+) and first excited (2+) 12C-core states, is considered. The model is applied to calculate total photodisintegration cross sections of the reaction 13C(γ, n)12C for energies below the Giant dipole resonance. The radial wavefunctions in initial- as well as final states are of the Saxon-Woods type.

Periodicity of the Oscillatory J Dependence of Diatomic Molecule Franck–Condon Factors

1975 ◽  
Vol 53 (16) ◽  
pp. 1560-1572 ◽  
Author(s):  
Robert J. Le Roy ◽  
Edward R. Vrscay
Keyword(s):  
Simple Formula ◽  
Radial Wave Function ◽  
Wave Functions ◽  
Final States ◽  
Rotational Constants ◽  
Radial Wave ◽  
Condon Factors ◽  
Oscillating Functions ◽  
Vibration Rotation ◽  
Franck Condon

Numerical calculations have shown that vibration–rotation interaction often contributes significantly to the J dependence of transition intensities of diatomic molecules. This occurs because centrifugal displacements of the vibrational wave functions cause the Franck–Condon amplitudes (radial overlap integrals) to behave as oscillating functions of J(J + 1). The present paper discusses the origin of this behavior and derives and tests a simple formula for predicting the periodicity of such oscillations. This procedure requires only a knowledge of the rotational constants and vibrational spacings of the initial and final states. It utilizes the result that the average centrifugal displacement rate of a diatomic molecule's radial wave function is approximately [Formula: see text], where Bν and Dν are the usual diatomic rotational constants.

scholarly journals Single electron capture into arbitrary states of bare projectiles from multi-electron targets

2018 ◽  
Vol 16 (2) ◽  
pp. 239-247
Author(s):  
Nenad Milojevic ◽  
Ivan Mancev
Keyword(s):  
Electron Capture ◽  
Cross Sections ◽  
Single Electron ◽  
Final States ◽  
Total Cross Sections ◽  
Single Electron Capture ◽  
Body Boundary ◽  
Impact Energies ◽  
Good Agreement ◽  
Prior Form

The prior form of four-body boundary-corrected first Born (CB1-4B) method is applied to calculate the total cross sections for single electron capture from the Kshell of multi-electron atoms (C, N, O, Ar) by fast projectiles (H+, He2+and Li3+). All calculations are carried out for electron capture into the arbitrary n, l, and m final states of the projectiles. The present results are found to be in very good agreement with the available experimental data at intermediate and high impact energies.

Resonance charge transfer between H(1s) and H + calculated by means of an approximation based on an expansion in atomic eigenfunctions

1961 ◽  
Vol 264 (1319) ◽  
pp. 547-557 ◽  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Atomic Hydrogen ◽  
High Energy ◽  
Wave Functions ◽  
Final States ◽  
Energy Limit ◽  
Full Account ◽  
The Cross ◽  
Resonance Charge

An expression for the cross-section describing electron capture by protons in atomic hydrogen is derived from an expansion based on atomic wave functions. Full account is taken of momentum transfer and of the non-orthogonality of the wave functions of the initial and final states by the method due to Bates. The cross-sections have been computed for proton energies from 100 to 1 MeV. In the low energy limit, the results agree with the p.s.s. calculations of Dalgarno & Yadav and in the high energy limit with the calculations of Brinkm an & Kramers.

Electron Excitation in Noble Gases

1975 ◽  
Vol 53 (7) ◽  
pp. 689-699 ◽  
Author(s):  
H. G. P. Lins De Barros ◽  
H. S. Brandi
Keyword(s):  
Differential Cross Section ◽  
Electron Impact ◽  
Cross Section ◽  
Cross Sections ◽  
Differential Cross ◽  
Noble Gases ◽  
Electron Excitation ◽  
Wave Functions ◽  
Total Cross Sections ◽  
Collision Processes

Calculations for cross sections for some states of Ne excited by electron impact have been carried out. A parametrization of total and differential cross section in the Born–Ochkur approximation has been proposed. Using this parametrization and appropriate wave functions for the states involved in the collision processes, differential and total cross sections have been calculated. The results have shown that this parametrization is very convenient to study this type of problem.

Introductory remarks on the study of the pion-nucleon interaction

1966 ◽  
Vol 289 (1419) ◽  
pp. 442-448 ◽  
Keyword(s):  
Cross Sections ◽  
Resonance Energy ◽  
High Energy ◽  
Nucleon Interaction ◽  
Nucleon System ◽  
Total Cross Sections ◽  
The Past ◽  
Polarized Proton ◽  
Pion Nucleon

Our knowledge of the scattering interactions in the pion-nucleon system has been developing rapidly during the past few years. For the π + p and π - p systems, total cross-section measurements have been extended upwards in energy to 20 GeV/c laboratory momentum. As Galbraith will report at this meeting, measurements of high precision have recently been carried out for π + p and π - p total cross-sections between 2·5 and 7GeV/c by Citron et al. (1964,1965) at Brookhaven. From these and earlier data, about ten excited nucleon states have become established, with mass values up to about 3200 MeV. These excited nucleon states are listed in table 1. In the resonance energy range, detailed angular distribution measurements have now been made up to the region of the fifth excited state ( N * 1/2 (2190)), and many of these new measurements will be reported at this meeting. The recent use of polarized proton targets has allowed a very direct means for the systematic and accurate study of the polarization properties of pion-nucleon scattering, and this technique has recently been exploited at the Nimrod accelerator of the Rutherford High Energy Laboratory at Chilton by the Murphy-Thresher group (Atkinson et al. 1966) for the determination of the spin and parity of the third and fourth resonance states, N * 1/2 (1688) and N * 1/2 (1920).

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