Excited states in 75As

1970 ◽  
Vol 48 (19) ◽  
pp. 2254-2264 ◽  
Author(s):  
Th. Paradellis ◽  
S. Hontzeas
Keyword(s):  
Excited States ◽  
Half Life ◽  
Gamma Ray ◽  
Collective Effects ◽  
Transition Rates ◽  
Electron Conversion ◽  
Conversion Coefficients ◽  
First Time ◽  
Coincidence Measurements

The gamma-ray spectrum of 75Se has been studied with a variety of Ge(Li) detectors. The energies and intensities of 15 lines have been accurately measured. Of these a 24.4 and 468.6 keV transition were substantiated for the first time in the gamma-ray spectrum. Ge(Li)–Ge(Li) coincidence measurements established the newly observed 24.4 keV transition. These experiments also substantiated the 80.8 keV transition (observed for the first time) deduced from electron conversion spectra. The accurate intensity values obtained in this work have been combined with proper literature data and conversion coefficients for various transitions have been determined. These data and recent half-life measurements of some excited states by other workers permitted us to calculate the transition rates in 75As. The data obtained indicate that the 198.6, 279.5, and 400.5 keV levels in 75As exhibit strong collective character, in contrast to the 264.6 keV level, which shows little influence of collective effects.

High spin states in 96Tc populated through the (α,n) reaction

1980 ◽  
Vol 58 (2) ◽  
pp. 174-190 ◽  
Author(s):  
H. A. Mach ◽  
M. W. Johns ◽  
J. V. Thompson
Keyword(s):  
Theoretical Model ◽  
High Spin ◽  
Spin Structure ◽  
Gamma Ray ◽  
Angular Distributions ◽  
Spin States ◽  
High Spin States ◽  
Gamma Coincidence ◽  
Electron Conversion ◽  
Conversion Coefficients

High spin states of 96Tc populated by the (α,n) reaction using alpha beams from 13 to 27 MeV have been studied. Gamma-ray energies and intensities, gamma–gamma coincidence probabilities, gamma-ray angular distributions, and electron conversion coefficients were determined at 18 MeV. In addition, some results taken at 14 MeV are reported.The high spin structure observed in this work includes the following levels: 49.3(6+), 318.8(6+), 574.7(7+), 926.9(9+), 946.5(8+), 1062.1(8+), 1138.8(8+), 1447.2(9+), 1702.8(10+), 1861.6(9+), 1922.3(11+), 2147.5(11+), 2213.5(10(+)), 2317.2(12+), 2396.8(11(+)), 2599.0((13)+), 2642.4((14)+), and 3020.1(12(+)).These experiments also clarify and extend the information obtained by previous workers. In particular, evidence is adduced for low-lying states at 0.0(7+), 34.3(4+), 45.3(5+), 120.3(3−), 177.0(5+), 226.2(2−), 227.0(4+), and 254.3(3+).The work identifies many other states of intermediate energy.Attenuation coefficients for states in 96Tc are calculated using a theoretical model.

Levels in 148Tb excited by the (6,7Li,xn) and (10B,xn) reactions

1979 ◽  
Vol 57 (3) ◽  
pp. 358-367 ◽  
Author(s):  
N. C. Singhal ◽  
M. W. Johns
Keyword(s):  
High Spin ◽  
Internal Conversion ◽  
Gamma Ray ◽  
Angular Distributions ◽  
Spin States ◽  
High Spin States ◽  
Internal Conversion Coefficients ◽  
Conversion Coefficients ◽  
Γ Ray ◽  
Coincidence Measurements

High spin slates in 148Tb have been excited by means of 144Sm(6Li,2n), 144Sm(7Li,3n), and 142Nd(10B,4n) reactions and studied by γ-ray and electron measurements. Gamma-ray singles, excitation functions, angular distributions, internal conversion coefficients, and γ–γ coincidence measurements have been made. A seven-fold gamma–gamma cascade feeding the 9+ isomeric state in 148Tb and originating in a level 4137 keV above that state is strongly excited. The spin and parity assignments are made on the basis of angular distribution and internal conversion coefficients. On the basis of these measurements, the 1006 keV transition is E3 in character; the half-life of the 1006 keV (12−) level is established to be 25 ± 2 ns.These experiments also confirm the existence of a number of high spin states in 148Gd seen by earlier workers.

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.

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.

A study of high spin states in 151Gd

1977 ◽  
Vol 55 (7-8) ◽  
pp. 690-713 ◽  
Author(s):  
H. J. Smith ◽  
M. W. Johns ◽  
G. Løvhøiden ◽  
J. V. Thompson ◽  
J. C. Waddington ◽  
...  
Keyword(s):  
Band Structure ◽  
Rotational Band ◽  
Gamma Ray ◽  
Level Structure ◽  
Negative Parity ◽  
Angular Distributions ◽  
Spin States ◽  
High Spin States ◽  
Conversion Coefficients ◽  
Coincidence Measurements

States in the transitional nucleus, 151Gd, excited by the (α,2n) reaction have been studied by gamma-ray and conversion electron measurements. Gamma-ray energies, intensities, excitation functions, and γ–γ coincidence measurements were used to establish the levels populated. Angular distributions involving measurements at seven angles from 0° to 90° and K-conversion coefficients have been used to make spin and parity assignments.The El character of the 65, 79, 340, 358, 406, and 462 keV transitions, which in the absence of K-conversion data had been tacitly assumed to be M1 by earlier workers leads to a significant revision of their parity assignments and interpretation of the level structure. The negative parity states at 1210, 1463, 1726, 2004, 2295, 2600, 2915, and 3237 keV form a well-developed rotational band based on the 11/2− [505] state at 1210 keV. The properties of this band in this nucleus are compared with those of the same band in a number of nearby nuclei. Two non-interacting negative parity bands with states at 0(7/2−), 706(11/2−), 1435(15/2−), 2078(19/2−), and 379(9/2−), 902(13/2−), 1511(17/2−), 2297(21/2−), respectively, have been found, as well as a number of other negative parity states of spin 7/2, 9/2, and 13/2. A complex positive band structure involving states at 784(11/2+), 852(13/2+), 1116(13/2+), 1346(17/2+), 1364(15/2+), 1677(17/2+), 1851(19/2+), 1853(21/2+), 2197(21/2+), 2325(23/2+), and 2405(25/2+) has been identified. By using a somewhat unusual set of parameters, we have been able to approach a description for the positive parity states in terms of the triaxial model of Meyer-ter-Vehn.

Levels populated in 193Ir from the beta decay of 193Os

1969 ◽  
Vol 47 (7) ◽  
pp. 727-746 ◽  
Author(s):  
R. H. Price ◽  
M. W. Johns ◽  
N. M. Ahmed ◽  
E. E. Habib
Keyword(s):  
Beta Decay ◽  
Internal Conversion ◽  
Gamma Ray ◽  
Magnetic Spectrometer ◽  
Mixing Ratios ◽  
Internal Conversion Coefficients ◽  
Conversion Coefficients ◽  
Coincidence Measurements

The beta and gamma ray transitions involved in the decay of 193Os have been studied using Ge(Li) and Nal(Tl) detectors and magnetic spectrometers, singly and in coincidence. Fifty-four gamma ray transitions have been observed and all but one classified on the basis of energy fit and β−γ and γ−γ coincidence measurements. The internal conversion coefficients of 25 of the stronger transitions were determined with a magnetic spectrometer operating at a resolution of ~0.1% in momentum, and multipole mixing ratios determined. The energies and spins of levels in 193Ir have been determined as follows: 0 (3/2+), 73.006 (1/2+), 138.887 (5/2+), 142.125 (+), 180.00(3/2+), 357.7 (7/2+), 361.79 (5/2+), 440.95 (+), 460.46 (3/2+), 557.29 (1/2+), 559.22 (5/2+), 660.09 (+), 667.13, 695.06 (3/2+), 712.08 (3/2+), 778.50,784.13, 848.94, 874.45, 891.57.

SPINS OF EXCITED STATES OF Os188

1959 ◽  
Vol 37 (6) ◽  
pp. 755-774 ◽  
Author(s):  
W. J. King ◽  
M. W. Johns
Keyword(s):  
Angular Correlation ◽  
Excited States ◽  
Beta Decay ◽  
Decay Scheme ◽  
Gamma Ray ◽  
Correlation Data ◽  
Conversion Coefficients

Seven excited states of Os188 populated through the beta decay of Re188 have been studied by gamma–gamma angular correlation experiments. The data for the various cascades fit the following theoretical functions: (all gamma-ray energies are in kev and the description following each cascade refers to the first transition) 478–155 (2–2–0, 99.7% E2, δ +ve), 931–155 (0–2–0), 672–633 (2–2–0), 97% M1, δ −ve or 3–2–0, 94% M1, δ −ve or conceivably 4–2–0), 828–633 (2–2–0, 98% M1, δ −ve or conceivably 3–2–0, 80% M1, δ −ve), 1132–633 (0–2–0), and 1308–633 (2–2–0, 98% M1, δ −ve). Some attenuation occurred in the correlations involving the 155-kev gamma ray. The K-conversion coefficients for the 478- and 633-kev transitions have been measured as 0.023 ± 0.003 and 0.010 ± 0.002 respectively, confirming the E2 character for these transitions obtained by angular correlation. These results, coupled with data concerning log ft values and gamma-ray intensities, lead to the following spin and parity assignments for levels in Os188: 155 (2+), 633 (2+), 1086 (0+), 1306 (2+ or 3+), 1461 (2+), 1765 (0+), 1941 (2+), and 1958 (1+ or 2+).The 631–137 correlation data in Os186 was found to fit an attenuated 2–2–0 function with the first transition 99% E2 and δ −ve. This result supports the established decay scheme for this nucleus.

One-step synthesis of well-dispersed polypyrrole copolymers under gamma-ray irradiation

2021 ◽  
Vol 12 (5) ◽  
pp. 645-649
Author(s):  
Yu Gu ◽  
Yuqing Qiao ◽  
Yusen Meng ◽  
Ming Yu ◽  
Bowu Zhang ◽  
...  
Keyword(s):  
Room Temperature ◽  
Gamma Ray ◽  
Gamma Ray Irradiation ◽  
One Step ◽  
First Time

Herein, we report for the first time the synthesis of polypyrrole copolymers with good solvent-dispersibility under gamma-ray irradiation at room temperature in air.

Gamma-Ray Angular Correlations and Lifetime Measurements for Some Excited States ofNe21

1969 ◽  
Vol 186 (4) ◽  
pp. 1174-1188 ◽  
Author(s):  
J. G. Pronko ◽  
C. Rolfs ◽  
H. J. Maier
Keyword(s):  
Excited States ◽  
Gamma Ray ◽  
Lifetime Measurements ◽  
Angular Correlations

LX-ray Spectra and E2 Internal Conversion Coefficients in Radon and Radium

1973 ◽  
Vol 28 (10) ◽  
pp. 1635-1641 ◽  
Author(s):  
A. G. de Pinho ◽  
M. Weksler
Keyword(s):  
Excited States ◽  
Internal Conversion ◽  
Electric Quadrupole ◽  
Alpha Decay ◽  
X Ray ◽  
Internal Conversion Coefficients ◽  
Conversion Coefficients ◽  
Good Agreement

The X-ray spectra resulting from the internal conversion of electric quadrupole transitions following the alpha decay of Th230 and Ra226 were analysed with a Si (Li) spectrometer. From the knowledge of the Coster-Kronig and fluorescence yields, the internal conversion coefficients of the E2 transitions from the first excited states in Ra226 and Rn222 could be deduced. Results are in good agreement with theoretical values.

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