Electric quadrupole transitions

1991 ◽  
Vol 69 (7) ◽  
pp. 855-863 ◽  
Author(s):  
W. V. Prestwich ◽  
M. A. Islam ◽  
T. J. Kennett
Keyword(s):  
Energy Dependence ◽  
Radiative Capture ◽  
Strength Function ◽  
Electric Quadrupole ◽  
Mass Dependence ◽  
Data Set ◽  
Direct Capture ◽  
Quadrupole Resonance ◽  
Capture Mechanism

A data set has been compiled consisting of 101 E2 strengths observed in neutron radiative capture. The E2 strength function is found to be consistent with a fifth power energy dependence and mass dependence characterized by a power of n = 1.87 ± 0.07. The observed strengths are on average consistent with those predicted on the basis of the giant quadrupole resonance. A reduction in strengths is apparent near mass regions 28, 82, and 157. Evidence is cited for the possible existence of a direct capture mechanism.

Nuclear Electric Quadrupole Resonance inβ-Gallium

1972 ◽  
Vol 28 (15) ◽  
pp. 970-971 ◽  
Author(s):  
S. L. Segel ◽  
R. D. Heyding ◽  
E. F. W. Seymour
Keyword(s):  
Electric Quadrupole ◽  
Quadrupole Resonance

scholarly journals Testing the modified dependence of the radiative strength function on different excitation energies in the light nucleus 28Al

2018 ◽  
Vol 39 (1) ◽  
pp. 47-63
Author(s):  
D. Knezevic ◽  
N. Jovancevic ◽  
A. M. Sukhovoj ◽  
L.V. Mitsyna
Keyword(s):  
Radiative Capture ◽  
Level Density ◽  
Strength Function ◽  
Mean Value ◽  
Excitation Energies ◽  
Radiative Strength Function ◽  
The Mean ◽  
Strength Functions ◽  
Gamma Transitions ◽  
New Hypothesis

Abstract The spectrum of random functions of level density as well as radiative strength functions of dipole E1- and M1-transitions of 28Al were determined. Obtained functions can reproduce very precisely the intensity of the two-step cascade following the radiative capture of thermal neutrons for a given energy of the primary transitions. The density of the observed intermediate levels can be reproduced correctly using the mean value of these functions. In this work we proposed a new hypothesis about the dependence of radiative strength functions for gamma-transitions in heated nucleus on the energy of excited levels. The results provide a solid basis that this new hypothesis allows to get realistic estimation on the parameters of nuclear structure in any nucleus, including the light ones.

The direct capture mechanism for intermediate energy nucleons

1966 ◽  
Vol 79 (2) ◽  
pp. 257-274 ◽  
Author(s):  
H. Gutfreund ◽  
G. Rakavy
Keyword(s):  
Intermediate Energy ◽  
Direct Capture ◽  
Capture Mechanism

The capture γ-ray spectrum of Mg

1990 ◽  
Vol 68 (3) ◽  
pp. 261-267 ◽  
Author(s):  
W. V. Prestwich ◽  
T. J. Kennett
Keyword(s):  
Magnetic Dipole ◽  
Cross Sections ◽  
Electric Quadrupole ◽  
Capture Cross ◽  
Direct Capture ◽  
Γ Rays ◽  
Γ Ray ◽  
Capture Cross Sections

The capture γ rays of natural Mg are analyzed. The results indicate neutron separation energies of 7333.57 ± 0.07, 11 093.09 ± 0.08, and 6443.29 ± 0.12 keV for the 25Mg, 26Mg, and 27Mg products. From the primary intensities estimates of 51.5 ± 2.5 and 201 ± 9 mb for the 24Mg and 25Mg capture cross sections are deduced. Refined level energies for the three product isotopes are calculated and compared with previous results. Direct capture effects for electric and magnetic dipole and electric quadrupole transitions are discussed.

THE ELECTRON SPIN RESONANCE OF Fe+3 IN SINGLE CRYSTALS OF SPODUMENE

1965 ◽  
Vol 43 (12) ◽  
pp. 2262-2275 ◽  
Author(s):  
A. Manoogian ◽  
F. Holuj ◽  
J. W. Carswell
Keyword(s):  
Electron Spin Resonance ◽  
Single Crystals ◽  
Electron Spin ◽  
Ground State ◽  
Electric Quadrupole ◽  
Spin Hamiltonian ◽  
Electric Field Gradients ◽  
Field Gradients ◽  
Spin Resonance ◽  
Quadrupole Resonance

The electron spin resonance (ESR) spectrum of Fe+3 in spodumene, LiAl(SiO3)2, has been investigated at 24 kMc/sec. One set of five "allowed" transitions between the magnetic sublevels of the 6S5/2 ground state has been detected. The following values have been assigned to the parameters occurring in the spin Hamiltonian (eq. (1)) (bnm in gauss): gx = 2.0086 ± 50, gy = 2.0100 ± 50, gx ± 2.0046 ± 25, b20 = −1 430, b22 = −282, b40 = −20, b42 = 108, b44 = −182. Consideration of electric field gradients measured by methods of electric quadrupole resonance and of the orthorhombic parameters b20 and b22 did not lead to a unique assignment of the Fe+3 impurity to one of the two available cationic sites in spodumene.

Renormalization of the γ-ray strength functions of light nuclei

2015 ◽  
Vol 24 (03) ◽  
pp. 1550018
Author(s):  
Bora Canbula ◽  
Sibel Erşan ◽  
Halil Babacan
Keyword(s):  
Radiative Capture ◽  
Level Density ◽  
Strength Function ◽  
Light Nuclei ◽  
Collective Effects ◽  
Density Parameter ◽  
Nuclear Level Density ◽  
Γ Ray ◽  
Strength Functions ◽  
Normalization Factors

γ-ray strength function is the key input for the photonuclear reactions, which have a special astrophysical importance, and should be renormalized by using the nuclear level density for calculating the theoretical average radiative capture width, but performing such renormalization is challenging for light nuclei. With this motivation, recently introduced level density parameter formula including collective effects is used to calculate the average radiative capture width of light nuclei, and therefore to renormalize their γ-ray strength functions. Obtained normalization factors are tested in (n, γ) reactions for the necessity of renormalization for light nuclei.

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