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%.

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.

scholarly journals On the Decay of 165Dy

1968 ◽  
Vol 23 (7) ◽  
pp. 962-967
Author(s):  
E. Bashandy ◽  
N. Ibrahiem ◽  
G. El-Sayad
Keyword(s):  
Decay Scheme ◽  
Internal Conversion ◽  
Level Structure ◽  
Low Energy ◽  
Conversion Electron Spectrum ◽  
Nuclear Models ◽  
Conversion Coefficients ◽  
Γ Rays ◽  
Double Focusing ◽  
Experimental Level

The internal conversion electron spectrum of transitions in the decay of (139 min) 165Dy to 165Ho has been studied using a high resolution iron-free double focusing β-ray spectrometer. In addition to γ rays previously reported eight new γ rays, mostly in the low energy region, have been observed. A decay scheme involving 17 excited levels is proposed for 165Ho. Multipolarity data, obtained from the measurements of absolute or ratios of conversion coefficients of γ rays, were utilized for assigning possible spins and parities to the levels of 165Ho. The experimental level structure is discussed in the light of nuclear models.

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.

Investigation of exotic states of 13C at low energy

2018 ◽  
Vol 27 (03) ◽  
pp. 1850025 ◽  
Author(s):  
N. Burtebayev ◽  
D. M. Janseitov ◽  
Zh. Kerimkulov ◽  
Y. S. Mukhamejanov ◽  
M. Nassurlla ◽  
...  
Keyword(s):  
Excited States ◽  
Cross Sections ◽  
Differential Cross ◽  
Ground State ◽  
Low Energy ◽  
Neutron Halo ◽  
Differential Cross Sections ◽  
Hoyle State ◽  
Exotic States ◽  
Diffraction Model

The differential cross-sections of the elastic and inelastic [Formula: see text]C scattering have been measured at E[Formula: see text][Formula: see text]MeV. The radii of the exited states: 3.09 [Formula: see text] and 8.86 [Formula: see text] MeV were determined using the Modified Diffraction Model. The radii of these excited states are larger than that of the ground state of [Formula: see text]C, confirming the suggestion that the 8.86 [Formula: see text] MeV state could be an analog of the Hoyle state in [Formula: see text]C and the 3.09 [Formula: see text] MeV state has a neutron halo. The possibility of coexistence of various exotic states in the structure of the [Formula: see text]C nucleus is shown.

scholarly journals On Anomalous Fluorescence of Symmetrical Polymethine Dyes

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
P. O. Kondratenko ◽  
Yu. M. Lopatkin
Keyword(s):  
Excited States ◽  
Ground State ◽  
Internal Conversion ◽  
Polymethine Dyes ◽  
Necessary Condition ◽  
Relaxation Processes ◽  
Sufficient Condition ◽  
Radiative Relaxation ◽  
Higher Excited States ◽  
Group Theoretical Analysis

The group-theoretical analysis of polymethine dyes (PMD) showed that relaxation processes between the states S3 and S1 are forbidden, either by radiation or by internal conversion. From the state S3, only transition to the ground state of the molecule is possible. Since the experimental data state that the quantum yield of S3 ⟶ S0 fluorescence does not exceed 1%, it is indicated that the internal conversion rate can be 2 orders of magnitude higher than the radiative relaxation rate of the molecule. Concerning the reasons for the appearance of fluorescence from the higher excited states of molecules, it can be asserted that the necessary condition for the appearance of S3 ⟶ S0 fluorescence is the absence of S0 ⟶ S1(v)-absorption in the region of the S0 ⟶ S3 transition. The sufficient condition is the corresponding symmetry of the excited states, which imposes a prohibition on the S3 ⟶ S1 relaxation process.

scholarly journals Analogues of Excited States in 91Zr

1969 ◽  
Vol 22 (4) ◽  
pp. 541 ◽  
Author(s):  
GA Jones ◽  
GC Morrison ◽  
RB Taylor
Keyword(s):  
Excitation Energy ◽  
Excited States ◽  
Single Particle ◽  
Ground State ◽  
Level Structure ◽  
Positive Parity

The level structure in 91Zr has been investigated by Cohen and Chubinsky (1963) with the 90Zr (d, p)91Zr reaction. They noted some 14 levels up to an excitation energy of 3�9 MeV. All these states were found to have positive parity and their structure is fairly well understood in terms of coupling a single-particle neutron to the ground state and the first two excited states of 90Zr (Ramavataram 1964). A study of the isobaric analogues of the 9lZr states with the 90Zr(p, pO)90Zr reaction was carried out by Moore (1964).

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