Levels in 89Rb Populated by the Beta Decay of 89Kr

1972 ◽  
Vol 50 (22) ◽  
pp. 2741-2752 ◽  
Author(s):  
W. F. S. Poehlman ◽  
B. Singh ◽  
M. W. Johns
Keyword(s):  
Excited States ◽  
Beta Decay ◽  
Gamma Rays ◽  
Large Volume ◽  
Ground State ◽  
Level Scheme ◽  
Gamma Coincidence ◽  
Coincidence Data ◽  
Coincidence Arrangement

The decay of 3.2 min 89Kr has been investigated with small and large volume Ge(Li) detectors used singly and in a dual parameter coincidence arrangement. A total of 162 gamma rays are identified with the decay of this isotope, 120 of which are placed in a level scheme on the basis of gamma–gamma coincidence evidence and the energy differences between established levels. Levels at 220.9, 497.7, 577.3, 586.1, 930.7, 931.5, 997.6, 1195.5, 1324.6, 1530.1, 1533.6, 1694.1, 1822.1, 1998.9, 2160.5, 2401.5, 2598.5, 2867.2, 3099.7, 3329.9, 3363.1, 3372.1, 3534.1, 3719.3, 4145.1, 4217.4, 4340.9, and 4487.5 keV are well established by coincidence data and many energy sums. The levels proposed at 2783.4, 3429.7, 3456.6, 3978.4, 4058.4, and 4406.5 keV are less securely established. The most probable spins of the ground state and the first two excited states arc 3/2−. 5/2− and 1/2− respectively. Improved energies and intensities of the gamma rays from the decay of 15 min 89Rb have also been determined.

STUDIES IN THE ACTIVE DEPOSIT OF ACTINIUM: PART II: THE DECAY OF 211Pb (AcB)

1965 ◽  
Vol 43 (3) ◽  
pp. 383-403 ◽  
Author(s):  
C. R. Cothern ◽  
R. D. Connor
Keyword(s):  
Gamma Rays ◽  
Level Scheme ◽  
Gamma Ray ◽  
Ground Level ◽  
Conversion Line ◽  
Point Energy ◽  
Correlation Studies ◽  
Absolute Intensities ◽  
Gamma Coincidence ◽  
Conversion Coefficients

Studies of the active deposit of actinium using a Siegbahn–Slatis beta-ray spectrometer and scintillation counters together with gamma–gamma coincidence work and gamma–gamma angular correlation measurements have led to the establishment of a new decay scheme for 211Pb and a level scheme for 211Bi involving five excited states.The gamma rays have the following energies and absolute intensities:[Formula: see text]Conversion-line studies yielded energy values for the transitions marked with an asterisk as 403.3 ± 0.5 and 426.5 ± 0.5 keV respectively. The K conversion coefficients of the 400- and 430-keV transitions have been determined as 0.091 ± 0.018 and 0.117 ± 0.024 respectively.Fermi analysis yields 1.378 MeV as the highest end-point energy of the beta partial spectra. The remaining end points and the component intensities as deduced from the level scheme are as follows:[Formula: see text]The much less accurate results from Fermi analysis of the complete active deposit are in reasonable agreement with these data.Angular correlation studies of the 430–400- and 706–400-keV gamma-ray cascades have yielded spins for the levels concerned: ground level (9/2), 400-keV level (7/2), 830-keV level (9/2), and 1 100-keV level (7/2). These spins are the only ones consistent with the experimental evidence and the theoretical arguments presented.

Levels of 186W from the Decay of 186Ta

1973 ◽  
Vol 51 (3) ◽  
pp. 241-256 ◽  
Author(s):  
S. C. Gujrathi ◽  
S. K. Mark
Keyword(s):  
Experimental Data ◽  
High Resolution ◽  
Excited States ◽  
Gamma Rays ◽  
Decay Scheme ◽  
Transition Probabilities ◽  
Recent Experimental Data ◽  
Particle State ◽  
Quasi Particle ◽  
Coincidence Data

Gamma rays from the decay of 10.5 min 186Ta have been studied using high resolution Ge(Li) detectors. More than 90 gamma rays have been observed. Several photo-peaks previously reported as single lines were found to be close doublets. The results of this study have been correlated with the published γ–γ coincidence data and the recent (d,d′) reaction work and a decay scheme for 186Ta has been constructed. The scheme incorporates more than 85 transitions among 23 excited states in 186W. The level at 1661 keV has been discussed in terms of a two-proton quasi-particle state arising from the Nilsson orbitals Ωπ[NnzΛ] = 7/2+[404] and 1/2+[411]. Several transition probabilities have been extracted and compared with other recent experimental data and with the calculations of Kumar and Baranger as well as with the predictions of various phenomenological models.

IDENTIFICATION OF HIGH-SPIN STATES IN NEUTRON-RICH 88,90,92Kr AND 86Se

2011 ◽  
Vol 20 (08) ◽  
pp. 1825-1832 ◽  
Author(s):  
K. LI ◽  
J. H. HAMILTON ◽  
A. V. RAMAYYA ◽  
S. H. LIU ◽  
X. Q. ZHANG ◽  
...  
Keyword(s):  
Angular Correlation ◽  
Excited States ◽  
High Spin ◽  
Level Scheme ◽  
Spontaneous Fission ◽  
Detector Array ◽  
Spin States ◽  
High Spin States ◽  
Coincidence Data

Level schemes of even–even neutron-rich 88-92 Kr and 86 Se have been investigated by measuring triple-γ coincidence data from the spontaneous fission of 252 Cf with the Gammasphere detector array. The level scheme of 88 Kr has been extended up to 7169 keV state. Several new excited states with new transitions have been identified in 90,92 Kr and 86 Se . Spins and parities have been assigned to levels in these nuclei by following regional systematics and angular correlation measurements. The level structures of the N = 52, 54, Se , Kr , and Sr isotones are discussed.

Level Structure of 171Tm

1972 ◽  
Vol 50 (6) ◽  
pp. 513-528 ◽  
Author(s):  
R. L. Graham ◽  
J. S. Geiger ◽  
M. W. Johns
Keyword(s):  
Excited States ◽  
Internal Conversion ◽  
Gamma Ray ◽  
Level Structure ◽  
Line Intensities ◽  
Gamma Coincidence ◽  
Coincidence Data ◽  
Conversion Coefficients ◽  
Beta Spectrometer

The properties of the γ-ray transitions in 171Tm, following beta decay of 7.5 h 171Er, have been studied using an iron-free π√2 beta spectrometer and Ge(Li) detectors, singly and in coincidence. The multipolarities of 8 lower-energy γ transitions have been established from a study of L- or M-subshell-internal-conversion lines. The measured K-line intensities of 20 higher-energy transitions yield K conversion coefficients and hence additional multipolarity assignments. Gamma-ray energy measurements, together with an extensive series of gamma–gamma coincidence experiments, have been used to establish the role of 59 (out of 65) γ transitions in the 171Tm level scheme. Sixteen excited states are identified at energies of 5.025 (3/2+), 116.6 (5/2+), 129.0 (7/2+), 326.7* (9/2+), 424.8 (7/2−), 635.4 (7/2+), 675.7 (3/2+), 737.2 (5/2+), 822.3* (7/2+), 912.8 (5/2+), 998.6 (7/2+), 1225.5* (3/2, 5/2, or 7/2+), 1284.7* (5/2+), 1296.3*, 1391.2*, and 1400.5* (5/2+) keV. The asterisks indicate levels which are new or at variance with those proposed by some other workers. The coincidence data does not support a level at 861 keV proposed by two other groups of workers on the basis of energy sums. Nilsson orbital assignments are proposed and discussed for 12 levels.

Low lying levels in 81Br

1969 ◽  
Vol 47 (20) ◽  
pp. 2255-2259 ◽  
Author(s):  
M. Salomon ◽  
C. Hojvat
Keyword(s):  
Excited State ◽  
Energy Level ◽  
Excited States ◽  
Ground State ◽  
Level Scheme ◽  
Coulomb Excitation ◽  
Transition Probability ◽  
Energy Level Scheme ◽  
First Excited State

Coulomb excitation of Br targets and the reaction 80Se(p,γ)81Br were used to populate the low lying excited states of 81Br and an energy level scheme is proposed. The reduced transition probability from the ground state to the first excited state of 81Br (276 keV) has been measured to be B(E2) = 410 ± 40 e2 f4.

THE DECAY OF Os191 AND Os193

1958 ◽  
Vol 36 (10) ◽  
pp. 1409-1429 ◽  
Author(s):  
S. V. Nablo ◽  
M. W. Johns ◽  
R. H. Goodman ◽  
A. Artna
Keyword(s):  
Excited States ◽  
Gamma Rays ◽  
Cross Sections ◽  
Decay Scheme ◽  
Internal Conversion ◽  
Gamma Ray ◽  
Internal Conversion Coefficients ◽  
Gamma Coincidence ◽  
Conversion Coefficients ◽  
Activation Cross Sections

The beta- and gamma-ray spectra of Os191 and Os193 have been studied with a magnetic beta-ray spectrometer, scintillation spectrometers, and coincidence circuits. The 14-hour isomer of Os191 decays via a 0.0742-Mev (M3) transition. Gamma rays of energy 0.0418 (100%, E3), 0.0809 (1%, M1 + E2), 0.1287 (100%, M1 + E2), and 0.1858 (0.1%) Mev have been found to be associated with the 14.6 ± 0.3 day decay of Os191 and an extension of the accepted decay scheme proposed. The following 19 transitions have been associated with the 31.5 ± 0.5 hour decay of Os193: 0.0730 (14%), 0.1068 (~1%), 0.1393 (10%), 0.180 (0.3%), 0.196 (0.1%), 0.243 (~0.2%), 0.2485 (0.3%), 0.2514 (0.4%), 0.278 (0.6%), 0.2810 (1.6%), 0.2885 (0.3%), 0.2994 (0.4%), 0.314 (0.3%), 0.3218 (1.7%), 0.3620 (0.6%), 0.3878 (1.6%), 0.4604 (4.1%), 0.4857 (0.3%), and 0.5585 (2.2%). The internal conversion coefficients for all the stronger transitions suggest that they are M1 + E2 in character. The decay energy of Os193 is 1.132 ± 0.005 Mev. Fermi analyses and beta–gamma coincidence experiments have established excited states of Ir193 at 0.073, 0.139, 0.281, 0.362, 0.460, and 0.559 Mev above the ground state. Six otherwise unclassified weak gamma rays can be accommodated if levels at 0.247, 0.315, and 0.613 Mev are included in the decay scheme.The activation cross sections of Os184 and Os190 are (2.2 ± 0.5) × 103and 5.3 ± 2 barns respectively, relative to Seren's value of 1.6 ± 0.4 barns for Os192.

scholarly journals Nuclear Weak Processes in Presupernova Stars

1996 ◽  
Vol 145 ◽  
pp. 165-172
Author(s):  
A. Ray ◽  
T. Kar ◽  
S. Sarkar ◽  
S. Chakravarti
Keyword(s):  
Excited States ◽  
Beta Decay ◽  
Ground State ◽  
Strength Function ◽  
Supernova Explosion ◽  
Decay Rates ◽  
Distribution Method ◽  
The Core ◽  
Weak Transition ◽  
Late Stages

The structure and the size of the core of massive presupernova stars are determined by the electron fraction and entropy of the core during its late stages of evolution; these in turn affect the subsequent evolution during gravitational collapse and supernova explosion phases. Beta decay and electron capture on a number of neutron rich nuclei can contribute substantially towards the reduction of the entropy and possibly the electron fraction in the core. Methods for calculating the weak transition rates for a number of nuclei for which no reliable rates exist (particularly for A > 60) are outlined. The calculations are particularly suited for presupernova matter density (p = 107 - 109 g/cc) and temperature (T = 2 - 6 × 109 °K). We include besides the contributions from the ground state and the known excited states, the Gamow-Teller (GT) resonance states (e.g. for beta decay rates, the GT+ states) in the mother nucleus which are populated thermally. For the GT strength function for transitions from the ground state (as well as excited states) we use a sum rule calculated by the spectral distribution method where the centroid of the distribution is obtained from experimental data on (p,n) reactions. The contribution of the excited levels and GT+ resonances turn out to be important at high temperatures which may prevail in presupernova stellar cores.

14.—Ground State Rotational Bands in 158Dy, 160Dy and 162Dy

1972 ◽  
Vol 70 ◽  
pp. 155-163 ◽  
Author(s):  
G. T. Ewan ◽  
G. I. Andersson
Keyword(s):  
Gamma Rays ◽  
Ground State ◽  
Gamma Ray ◽  
Angular Distributions ◽  
Rotational Bands ◽  
Weak Evidence ◽  
Gamma Coincidence ◽  
Inertia Model ◽  
Coincidence Spectra ◽  
Variable Moment

SynopsisLevels in the ground state bands of 158Dy, 160Dy and 162Dy have been populated by (α, 2n) reactions on metallic targets of separated 156Gd, 158Gd and 160Gd isotopes. Two Ge(Li) detectors were used to study singles gamma-ray spectra, gamma-ray angular distributions, gamma-gamma coincidence spectra and relative yields of gamma-rays for bombarding energies from 20 to 27 MeV. Transitions from all levels in the ground state bands up to the 12+ member were identified and the following level energies in keV established: 158Dy: 0 (0+), 99·0 (2+), 317·4 (4+), 637·9 (6+), 1044·1 (8+), 1520·1 (10+) and 2049·4 (12+); 160Dy: 0 (0+), 86·7 (2+), 283·7 (4+), 581·4 (6+), 967·4 (8+), 1429·0 (10+), 1951·7 (12+); 162Dy: 0 (0+), 80·7 (2+), 265·7 (4+), 548·5 (6+), 921·1 (8+), 1374·8 (10+) and 1901·0 (12+). There is weak evidence for the 14+ levels in 158Dy and 160Dy. The level energies are compared with calculated values using the variable moment of inertia model.

Decay of 142La

1971 ◽  
Vol 49 (9) ◽  
pp. 1179-1185 ◽  
Author(s):  
S. L. Tong ◽  
W. V. Prestwich ◽  
K. Fritze
Keyword(s):  
Excited States ◽  
Beta Decay ◽  
Gamma Rays ◽  
Proportional Counter ◽  
Decay Scheme ◽  
Branching Ratios ◽  
Coincidence Measurement

The energies of the gamma rays following the beta decay of 92.5 min 142La have been precisely measured, and a coincidence measurement with a NaI(Tl) and Ge(Li) system was made by gating the NaI(Tl) at 641 keV. With these results, the decay scheme of 142Ce derived by Prestwich and Kennett was modified. The beta branching ratios of the decay of 142La to the ground and excited states of 142Ce have also been obtained by simultaneous gamma and 4π beta countings with a 3 in. × 3 in. NaI(Tl) detector and a 4π-proportional counter.

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