DISINTEGRATION OF Au198

1954 ◽  
Vol 32 (2) ◽  
pp. 153-166 ◽  
Author(s):  
L. G. Elliott ◽  
J. L. Wolfson ◽  
M. A. Preston
Keyword(s):  
Excited States ◽  
Magnetic Dipole ◽  
Ground State ◽  
Conversion Coefficient ◽  
Electric Quadrupole ◽  
Β Decay ◽  
Third Order ◽  
Decay Interaction ◽  
Forbidden Transition ◽  
Γ Ray

In addition to the 411.77 kev. γ-ray transition, two γ-ray transitions of energies 676.5 ± 0.8 kev. and 1088.9 ± 0.9 kev. have been observed in Hg198 following the disintegration of Au198. The intensities of these transitions were found to be (8.20 ± 0.56) × 10−3 and (1.63 ± 0.12) × 10−3 per disintegration respectively. The K conversion coefficient of the 676.5 kev. transition was measured as 0.0224 ± 0.0019, identifying the radiation as a mixture of magnetic dipole and electric quadrupole. The K conversion coefficient of the 1088.9 kev. transition was measured as 0.00450 ± 0.00034, identifying this radiation as electric quadrupole.A β-transition to the ground state of Hg198, of energy 1371 kev. and intensity (2.5 ± 0.5) × 10−4 per disintegration, has been observed and identified as a third order forbidden, transition. The shape of this spectrum has been studied above the end point of the intense 959 kev. β-transition. Of the four combinations considered for the β-decay interaction form, viz. SA, VA, ST, VT, it was found that the experimental shape can be fitted by any one of VA, ST, or VT, but not by SA. The log f0 t value for the transition is 11.7.A disintegration scheme is proposed in which the excited states of Hg198 at 412 and 1089 kev. are each assigned spin 2 and even parity and the ground state of Au198 spin 3 and odd parity.

Low-Lying Positive-Parity States in 101Tc

1972 ◽  
Vol 50 (13) ◽  
pp. 1511-1517 ◽  
Author(s):  
W. B. Cook ◽  
M. W. Johns ◽  
J. S. Geiger ◽  
R. L. Graham
Keyword(s):  
Excited States ◽  
Ground State ◽  
Decay Scheme ◽  
Internal Conversion ◽  
Conversion Coefficient ◽  
Low Energy ◽  
Positive Parity ◽  
Β Decay ◽  
Energy Transitions ◽  
Conversion Measurement

Internal conversion measurement studies of the 14.6 min 101Mo β decay have led to the discovery of the following low-energy transitions in 101Tc: 6.281 ± 0.007 (75.4 ± 9%), 9.317 ± 0.010 (97 ± 1%), and 15.606 ± 0.015 keV (1.9 + 0.3%). From relative L-subshell intensities, the 6.281 and 9.317 keV transitions are found to be M1 with E2 admixtures of 0.010 ± 0.005% and 0.021 + 0.006% respectively; the weak 15.606 keV transition is E2 in character. These transitions establish excited states in 101Tc at 9.317 ± 0.010 and 15.601 ± 0.009 keV. The measured multipolarities together with decay scheme considerations lead to Jπ values of 9/2 +, 7/2 +, and 5/2 + for the ground state, the 9.317, and the 15.601 keV states respectively. Since these transitions were not observed in earlier studies of the β decay of 101Mo, quoted decay energies have been 15.6 keV too low. The measured K-conversion coefficient of the 80.926 keV transition shows that it is M1 with an E2 component of < 9%.

Heavy-ion storage ring measurement of forbidden transition rates between ground-configuration levels in Si6+ and Si8+ ions

1998 ◽  
Vol 76 (11) ◽  
pp. 899-906 ◽  
Author(s):  
E Träbert ◽  
A Wolf ◽  
E H Pinnington ◽  
J Linkemann ◽  
E J Knystautas ◽  
...  
Keyword(s):  
Magnetic Dipole ◽  
Storage Ring ◽  
Theoretical Data ◽  
Electric Quadrupole ◽  
Heavy Ion ◽  
Transition Rates ◽  
Natural Level ◽  
Forbidden Transition ◽  
Ion Storage ◽  
34.50 Fa

The decay by magnetic dipole and electric quadrupole (M1 and E2) transitions of the 2s22p2 1D2 level in the ground complex of the C-like ion Si8+ and the 2s22p4 1D2 level in the O-like ion Si6+ have been optically observed with ions circulating in a storage ring. The measured natural level lifetimes of (38.3 ± 0.3) ms for Si8+ and (636 ± 0.7) ms for Si6+ corroborate theoretical data for such forbidden decays in multicharged ions of astrophysical interest. PACS Nos.: 32.70.Cs, 32.30.Jc, 34.50.Fa

AN INTERPRETATION OF THE LOW-LYING EXCITED STATES OF Mg25 AND Al25

1958 ◽  
Vol 36 (3) ◽  
pp. 378-404 ◽  
Author(s):  
A. E. Litherland ◽  
H. McManus ◽  
D. A. Bromley ◽  
H. E. Gove ◽  
E. B. Paul
Keyword(s):  
Excited States ◽  
Ground State ◽  
Salient Feature ◽  
Negative Parity ◽  
State Transitions ◽  
Rotational Model ◽  
Rotational States ◽  
Γ Ray ◽  
Deuteron Stripping ◽  
Experimental Values

A description of the experimental results obtained for Mg25 and Al25 is given based upon the assumption that the excited nuclear states are rotational states. In Mg25 and Al25 members of four rotational bands can be identified. The band based on the ground state can be assigned K = 5/2 whilst the three excited-state bands, two positive parity and one negative parity, can be assigned K = 1/2. The dipole γ-ray transitions between the K = 1/2 bands and the ground state K = 5/2 band are forbidden on the rotational model and it is a salient feature of the γ-ray cascading in Mg25 and Al25 that the ground-state transitions are always amongst the weakest transitions from excited states assigned to K = 1/2 bands. Besides giving a quantitative account of the γ-ray decay of the excited states the rotational model also predicts the number and type of the bands observed. The experimental values of the Mg24(d, p)Mg25 deuteron stripping reduced widths can also be approximately predicted by the model.

The 12 C(γ, 3α) reaction energy levels of 8 Be and 12 C

1955 ◽  
Vol 228 (1174) ◽  
pp. 376-396 ◽  
Keyword(s):  
Ground State ◽  
Energy Levels ◽  
Electric Quadrupole ◽  
Angular Distributions ◽  
Reaction Energy ◽  
Reaction Proceeds ◽  
Γ Ray ◽  
Relationship Of ◽  
The Relationship ◽  
Α Particles

The mechanism of the 12 C(γ, 3α) reaction, for γ-ray energies, E γ , up to about 40 MeV, has been determined from a study of over 2500 stars in nuclear emulsions. The study includes investigation of the angular distributions and correlations of the α-particles. The reaction is initiated mainly by electric-dipole and electric-quadrupole γ-ray interaction, the former being unexpectedly strong when E γ < 20 MeV. For E γ < 25 MeV the reaction proceeds mainly by transitions to the ground-state of 8 Be (spin J = 0), and to 2⋅95 ± 0⋅10 MeV ( J = 2) and 4⋅0 ± 0⋅1 MeV ( J = 2 or 4) levels of 8 Be. Transitions to levels near 6, 10 and 15 MeV (all J = 0, 2 or 4) become predominant when 25 MeV ≤ E γ <26 MeV. For E γ ≥ 26 MeV, most transitions lead to 16⋅8 ± 0⋅2 MeV ( J = 2) and 17⋅6 ± 0⋅2 MeV ( J = 2, possibly 0) levels, and possibly to a further 16⋅4 ± 0⋅2 MeV ( J = 0 or 2) level, levels which have not been detected in other reactions. The reaction mechanism is interpreted in terms of competing modes of decay of a compound nucleus, demonstrating the strong influence of the isotopic spins ( T ) of the levels of 12 C and 8 Be involved. For example, the 2 + levels of 12 C involved when 16 MeV ≤ E γ <20 MeV are (unexpectedly) found to have T = 1, and the 16⋅8 and 17⋅6 MeV levels of 8 Be are also found to have T = 1. The relationship of the 12 C (γ, 3α) reaction to other 12 C photodisintegration reactions (including some new reactions established during the present experiments) is discussed.

THE TOTAL INTERNAL CONVERSION COEFFICIENT OF THE 279-kev TRANSITION FOLLOWING THE DECAY OF Hg203 AS MEASURED BY A NEW COINCIDENCE METHOD

1962 ◽  
Vol 40 (4) ◽  
pp. 383-392 ◽  
Author(s):  
J. G. V. Taylor
Keyword(s):  
Standard Deviation ◽  
Internal Conversion ◽  
Conversion Coefficient ◽  
Internal Conversion Coefficient ◽  
Coincidence Method ◽  
Β Decay ◽  
A Value ◽  
Conversion Coefficients ◽  
Γ Ray ◽  
Total Conversion Coefficient

Using a new coincidence method, the total internal conversion coefficient for the 279-kev transition following the β-decay of Hg203 has been measured with a standard deviation of about 1%. The method which employs a 4πβ–γ coincidence arrangement is based on the differential absorption of β-particles and conversion electrons in 4π geometry. For determining the absolute efficiencies of γ-ray spectrometers or ion-chambers, the method has the advantage of yielding directly the number of γ-ray quanta emitted per Hg203 disintegration without requiring any knowledge of the K:L:M conversion ratios. Likely sources of systematic error have been investigated and their effect has been shown to be smaller than the quoted standard deviation. The value obtained is α = 0.2262 ±.0019 or γ/β = 0.8155 ±.0015, in excellent agreement with the recent β-ray spectrometer measurements of Nijgh et al. This is of interest because a number of widely differing values of conversion coefficients for this transition have been reported. If the K/(L+M+N) conversion ratio of 2.60 ±.06 found by Nijgh et al. is combined with our total conversion coefficient, a value αK = 0.1633 ±.0017 is obtained.

scholarly journals Electric quadrupole (E2) and magnetic dipole (M1) transitions for doubly and triply ionized krypton, xenon, and radon

2019 ◽  
Vol 97 (5) ◽  
pp. 529-536
Author(s):  
Selda Eser ◽  
Leyla Özdemir
Keyword(s):  
Magnetic Dipole ◽  
Atomic Structure ◽  
Ground State ◽  
Transition Probabilities ◽  
Electric Quadrupole ◽  
General Purpose ◽  
Oscillator Strengths ◽  
Ground State Configuration ◽  
Forbidden Transitions ◽  
State Configuration

We have reported the wavelengths, transition probabilities (or rates), oscillator strengths, and line strengths for forbidden transitions (electric quadrupole, E2, and magnetic dipole, M1) in doubly and triply ionized krypton, xenon, and radon using the general-purpose relativistic atomic structure package (GRASP). The results obtained from transitions between the levels of ground state configuration are in agreement with other available results in the literature. The data on forbidden transitions between high levels for these ions have been firstly presented in this work.

The magnetic dipole and electric quadrupole moments of dysprosium 161 and 163

1958 ◽  
Vol 245 (1240) ◽  
pp. 118-127 ◽  
Keyword(s):  
Magnetic Dipole ◽  
Ground State ◽  
Axial Symmetry ◽  
Dipole Moments ◽  
Electric Quadrupole ◽  
Magnesium Nitrate ◽  
Quadrupole Moments ◽  
Nuclear Spins ◽  
Paramagnetic Resonance ◽  
Electronic Ground

Paramagnetic resonance has been observed at 4.2 °K and a wavelength of 3.1 cm in magnetically dilute crystals of the acetate and double magnesium nitrate of dysprosium. Values for the nuclear spins and nuclear magnetic dipole moments of the odd isotopes 161 Dy and 163 Dy have been deduced from the spectrum in dysprosium acetate, although the spectrum does not have axial symmetry and cannot be analyzed in detail. More reliable values for these moments have been obtained from the spectrum of dysprosium double nitrate, which has axial symmetry. It has also been possible to make an approximate calculation of the electronic ground state of dysprosium ions in this salt and estimate the nuclear electric quadrupole moments. The values of the moments are: 161 µ = — 0.37 ± 0.04 n.m .; 163 µ = + 0.51 ± 0.06 n.m .; and, in units of 10 -24 cm 2 , 161 Q = + 1.1 ± 0.4; 163 Q = + 1.3 ± 0.4. For each isotope, only the relative signs of the two moments were determined experimentally; the signs quoted above are suggested as the most probable ones.

Microscopic description of ground state magnetic moment and low-lying magnetic dipole excitations in heavy odd-mass 181Ta nucleus

2016 ◽  
Vol 25 (08) ◽  
pp. 1650053 ◽  
Author(s):  
Emre Tabar ◽  
Hakan Yakut ◽  
Ali Akbar Kuliev
Keyword(s):  
Excited States ◽  
Magnetic Dipole ◽  
Ground State ◽  
Magnetic Moments ◽  
Nuclear Model ◽  
Spurious State ◽  
Restoration Method ◽  
State Mixing ◽  
Self Consistency

The ground state magnetic moments and the low-lying magnetic dipole (Ml) transitions from the ground to excited states in heavy deformed odd-mass [Formula: see text]Ta have been microscopically investigated on the basis of the quasiparticle-phonon nuclear model (QPNM). The problem of the spurious state mixing in M1 excitations is overcome by a restoration method allowing a self-consistent determination of the separable effective restoration forces. Due to the self-consistency of the method, these effective forces contain no arbitrary parameters. The results of calculations are compared with the available experimental data, the agreement being reasonably satisfactory.

Dependence of B(E2) and B(M1) transition strengths on energy and spin of excited states of 18F

2018 ◽  
Vol 33 (32) ◽  
pp. 1850188
Author(s):  
Rajesh Kharab
Keyword(s):  
Excitation Energy ◽  
Excited States ◽  
Magnetic Dipole ◽  
Potential Model ◽  
Transition Probabilities ◽  
Electric Quadrupole ◽  
Spin Parity ◽  
Model Based ◽  
Reduced Transition Probabilities ◽  
Simple Potential

The dependence of reduced transition probabilities corresponding to electric quadrupole [B(E2)] and magnetic dipole [B(M1)] transition occurring in [Formula: see text]F nucleus on excitation energy and spin parity of the states involved in the transition has been investigated within the framework of simple potential model based on M3Y interaction. It is found that B(E2) increases with increasing excitation energy irrespective of the spin of excited states while B(M1) is very sensitive to the spin of the excited states and is independent of excitation energy.

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