RADIOACTIVE DECAY OF W188

1962 ◽  
Vol 40 (6) ◽  
pp. 677-686 ◽  
Author(s):  
J. C. Roy
Keyword(s):  
Excited State ◽  
Gamma Rays ◽  
Ground State ◽  
Half Life ◽  
Decay Scheme ◽  
Radioactive Decay ◽  
Beta Transition ◽  
Upper Limit ◽  
Gamma Radiations

The half-life of W188 has been measured to be 69.4 ± 0.5 days. The gamma radiations emitted in the decay of W188 have been studied with an NaI scintillation spectrometer, and the beta radiations by absorption in aluminum. Three gamma rays with energies of 0.290 ± 0.005, 0.227 ± 0.005, and 0.063 ± 0.005 Mev were observed. The intensities of these gamma rays were measured relative to those gamma rays from the daughter activity Re188. The W188 gamma intensities thus deduced are respectively 0.002, 0.001, and about 0.001 per disintegration. The 0.227 and 0.063 gamma rays are in coincidence. It logically follows from the gamma results that 99.3% of the beta radiations go to the ground state of Re188 with an energy of 0.36 ± 0.04 Mev (determined by Feather analysis), while about 0.4% go to an excited state at 0.290 Mev; an upper limit of 0.3% has been set for a beta transition to the 0.063 state. A decay scheme for W188 is proposed.

RADIOACTIVE DECAY OF Au200

1959 ◽  
Vol 37 (4) ◽  
pp. 385-395 ◽  
Author(s):  
J. C. Roy ◽  
L. P. Roy
Keyword(s):  
Gamma Rays ◽  
Half Life ◽  
Decay Scheme ◽  
Radioactive Decay ◽  
End Point ◽  
Gamma Radiations

The half-life of Au200 has been measured to be 48.4 ± 0.3 minutes. The beta radiations emitted in the decay of Au200 have been studied by absorption in aluminum, and the gamma radiations with a multichannel scintillation spectrometer. Two beta rays with end-point energies of 2.25 ± 0.20 and 0.7 ± 0.1 Mev and respective abundance of (75 ± 3)% and (25 ± 3)% were detected. Three gamma rays with energies of 0.367, 1.23, and 1.60 Mev were observed. It was established that the 0.367- and 1.23-Mev gamma rays are in coincidence. A decay scheme for Au200 is proposed.

Decay of 103Ag

1969 ◽  
Vol 47 (4) ◽  
pp. 419-427 ◽  
Author(s):  
H. Bakhru ◽  
R. I. Morse ◽  
I. L. Preiss
Keyword(s):  
Gamma Rays ◽  
Compound Nucleus ◽  
Ground State ◽  
Half Life ◽  
Decay Scheme ◽  
Gamma Ray ◽  
Mass Difference ◽  
Direct Interaction ◽  
Direct Process ◽  
Silver Compound

The reaction 14N + 11B forming a silver compound nucleus and the direct interaction of 107Ag + 14N were utilized to produce the isotope 103Ag. In both instances the 103Ag results from the subsequent evaporation of nucleons from either the Ag compound nucleus or from the 105Ag* reaction intermediate in the case of the direct process. The decay of this isotope was studied using Ge(Li) detectors as well as with standard scintillation counters. The beta- and gamma-ray measurements confirm three beta groups of maximum energies 1.31 ± 0.05 MeV (60%), 1.03 ± 0.05 (30%), and 0.500 ± 0.1 MeV (10%) and gamma rays of energies 0.118, 0.148, 0.235, 0.268, 0.420, 0.540, 0.555, 0.585, 0.655, 0.740, 1.002, 1.1, 1.14, 1.27, 1.36, and 1.56 MeV all decaying with a half-life 1.1 h. Coincidence studies show that the 0.118 MeV gamma ray is in coincidence with 0.148, 0.511, 0.555, 0.740, 1.0, and 1.1 MeV gamma rays; the 0.148 MeV gamma ray with the 0.118, 0.511, 0.555, 0.740, 1.0, and 1.1 MeV gamma rays; the 0.235 MeV gamma ray with the 0.420, 0.511, 0.585, 0.740, 1.04, and 1.13 MeV gamma rays; the 0.540 MeV gamma ray with the 0.511 and 0.820 MeV gamma rays; and the 0.820 MeV gamma ray with the 0.511 and 0.740 MeV gamma rays only. Two beta groups of maximum energies 1.03 and 0.5 MeV are observed to be in coincidence with the 0.148 and 0.268 MeV transitions and with the 0.555 and 0.820 MeV gamma rays as a gate, only the beta group of energy 0.5 ± 0.1 MeV appears. Based on the above observation, a decay scheme of 103Ag is proposed and the results are discussed. The half-life of 118 keV level is measured by delayed coincidence and found to be (1.9 ± 0.4) × 10−9 s indicating an M1 multipolarity for this transition. The mass difference between the ground state of 103Ag and 103Pd is found to be 2.32 MeV.

scholarly journals The energy of disintegration of radio-phosphorous [P 30 ]

1935 ◽  
Vol 152 (877) ◽  
pp. 714-723 ◽  
Keyword(s):  
Excited State ◽  
Total Energy ◽  
Continuous Spectrum ◽  
Atomic Number ◽  
Particle Bombardment ◽  
Ground State ◽  
Radioactive Elements ◽  
Upper Limit ◽  
Association Meeting ◽  
The Difference

The exact masses of the nuclei are quantity of great interest depending directly on the forces of cohesion between the nuclear particles. Already much valuable information has been obtained about the lighter element both by mass-spectrographic methods and by the study of atomic dis-integrations. The discovery of the new radioactive elements has extended greatly the number of nuclei open to investigation, but since nearly all of these disintegrate by emitting either positrons or electrons forming a continuous spectrum we meet here the same difficulty in determining the total energy change in the disintegration as with the natural β-ray bodies. In this latter case Henderson* has proved the correcting of the suggestion of Ellis and Mott that the difference of energy of two nuclei, apart from γ-emission, is given by the upper limit of the β-ray spectrum. However, as was emphasized by Cockroft at the British Association Meeting at Norwich, in September, 1935, this is a point which needs verification in the region of low atomic number and particularly for positron disintegration. We have attempted to obtain some information on this point by investigating the disintegration of radio-phosphorus [P30] formed from aluminium by α-particle bombardment, The disintegration of radio phosphorus has already been investigated several times, but there is such a notable disagreement between the values given by different observers for the energy of the upper limit that we felt fresh experiments were needed, further, it is necessary to determine whether the upper limit corresponds to the formation of the ground state or of an excited state of the product nucleus.

Beta decay of 187W

1970 ◽  
Vol 48 (9) ◽  
pp. 1040-1054 ◽  
Author(s):  
A. W. Herman ◽  
E. A. Heighway ◽  
J. D. MacArthur
Keyword(s):  
Excited State ◽  
Beta Decay ◽  
Decay Scheme ◽  
Decay Energy ◽  
Beta Transition ◽  
Point Energy ◽  
Absolute Intensities ◽  
Gamma Coincidence ◽  
First Excited State ◽  
Coincidence Measurements

Coincidence studies have established in the decay scheme of,187W the existence of transitions of energy 7, 36, 77, 455, 589, and 639 keV with intensities of 3.0 ± 0.5%, 0.50 ± 0.06%, 0.31 ± 0.07%, 0.05 ± 0.02%, 0.14 ± 0.04%, and 0.05 ± 0.02% respectively as well as yielding the absolute intensities of the well-known transitions in 187Re. In addition the beta–gamma coincidence measurements have shown that (1) a first-forbidden unique transition feeds the first-excited state of 187Re, (2) there is at most a very weak beta transition to the level at 512 keV, (3) there is no inner beta group of about 300 keV end-point energy and intensity 8% as indicated by several earlier investigations, and (4) the decay energy of 187W to 187Re is 1311 ± 2 keV. The relevance of these observations to the structure of 187Re is discussed.

scholarly journals Nuclear Structure Investigations of some Medium-Weight Isotopes

2021 ◽  
Author(s):  
◽  
Gavin Wallace
Keyword(s):  
Nuclear Structure ◽  
Beta Decay ◽  
Cross Section ◽  
Gamma Rays ◽  
Half Life ◽  
Decay Scheme ◽  
Gamma Ray ◽  
Calculated Cross Section ◽  
Beta Spectrum ◽  
Gamma Ray Detectors

<p>This thesis describes the methods and results of investigations made to determine the decay schemes of three short-lived isotopes 112Ag, 114Ag and 116Ag. A total of 76 gamma-rays was observed with a Ge(Li) detector in the gamma-radiation which follows the Beta-decay of 112Ag to levels of 112Cd. gamma- gamma coincidence and angular correlation measurements were made with Ge(Li)-NaI(T1) and NaI(T1)-NaI(T1) systems. A decay scheme consistent with the present data is proposed. Cross sections for the reactions 112Cd(n,p)112Ag and 115In(n, alpha)112Ag were measured, and the half-life of the 112Ag decay was found to be 3.14 plus-minus 0.01 hr. The decay scheme of 114Ag was studied with Ge(Li) gamma-ray detectors and plastic Beta-ray detectors. 9 of the 11 gamma-rays observed in the decay were incorporated into 114Cd level structure previously determined by conversion electron measurements on the 113Cd(n,gamma)114Cd reaction. The endpoint energy of the Beta-decay was determined as 4.90 plus-minus 0.26 MeV; no branching was evident in the Beta-spectrum. A decay scheme is proposed for which the Beta-branching was deduced from the measured gamma-ray yield and a calculated cross section value for the 114Cd(n,p)114Ag reaction. The 114Ag half-life was determined as 4.52 plus-minus 0.03 sec; a search for a previously reported isomeric state of 114Ag was unsuccessful. Ge(Li) and NaI(T1) gamma-ray detectors were used to study the direct and coincidence spectra that result from the decay of 116Ag, the half-life of which was found to be 2.50 plus-minus 0.02 min. 53 gamma-rays were observed from this decay. The Beta-branching to the 17 excited states of 116Cd in the proposed decay scheme was derived from the measured gamma-ray yield and a calculated cross section value for the 116Cd(n,p)Ag reaction. Spin and parity assignments for ihe energy levels of 116Cd are made. An investigation of the applicability of two collective models to nuclear structure typical of the Cd nuclei studied demonstrated that one of the models was misleading when applied to vibrational nuclei. A potential function was developed in the other model to extend the investigation to include a study of the transition between extremes of collective motion. This was used to examine the correspondence between nuclear level schemes representative of rotational and vibrational excitations.</p>

Proton?Capture Gamma Rays from Nitrogen?13

1962 ◽  
Vol 15 (3) ◽  
pp. 443 ◽  
Author(s):  
AW Parker ◽  
GG Shute
Keyword(s):  
Angular Distribution ◽  
Excited State ◽  
Elastic Scattering ◽  
Gamma Rays ◽  
Ground State ◽  
Recent Experiment ◽  
Gamma Ray ◽  
Angular Distributions ◽  
Proton Capture ◽  
Yield Curves

From a recent experiment in this laboratory (Shute et al. 1962) on the elastic scattering of protons from 12C, resonance levels (E13N, J1t) of 13N were obtained at the laboratory bombarding energies (Ep) shown in Table 1. To confirm these results, an investigation of the yield and angular distribution of gamma rays from the reaction 12C(p'YO)13N and 12C(p'Yl)13N was undertaken. Accordingly, the theoretical angular distributions, W(8), for the gamma ray (Yo) to the ground state of 13Na-) and also for the gamma ray (Yl) to the 1st excited state of 13Na+) were evaluated on the assumptions that overlap of levels in 13N is small and lowest order multipoles are involved. As angular distributions are parity insensitive, these were found to be identical for the two gamma rays expected. The simpler of these angular distributions are also shown on the table. The expected angular distributions indicate that 90� is a suitable angle for yield curves.

THE ANGULAR DISTRIBUTION OF GAMMA RAYS IN THE C12(p,p′γ) REACTION

1953 ◽  
Vol 31 (2) ◽  
pp. 189-193 ◽  
Author(s):  
H. E. Gove ◽  
N. S. Wall
Keyword(s):  
Angular Momentum ◽  
Angular Distribution ◽  
Excited State ◽  
Proton Beam ◽  
Gamma Rays ◽  
Ground State ◽  
Expansion Formula ◽  
First Excited State ◽  
Incoming Proton

Protons of 7.1 Mev. energy from the MIT cyclotron have been used to investigate the angular distribution of gamma rays from the C12(p,p′γ) reaction with respect to the incoming proton beam. These gamma rays result from transitions between the first excited state of C12 at 4.45 Mev. and the ground state. The resulting distribution can be fitted by the expansion[Formula: see text]which is consistent with an assignment of two for the angular momentum of the first excited state of C12.

SUCCESSIVE DECAYS FROM Pr137 AND Ce137m: DECAY OF ADJACENT PRASEODYMIUM ISOTOPES

1958 ◽  
Vol 36 (11) ◽  
pp. 1487-1508 ◽  
Author(s):  
G. T. Danby ◽  
J. S. Foster ◽  
A. L. Thompson
Keyword(s):  
Excited State ◽  
Small Group ◽  
Electron Capture ◽  
High Spin ◽  
Gamma Rays ◽  
Isomeric State ◽  
Ground State ◽  
Branching Ratios ◽  
Spin States ◽  
High Spin States

The decay of Pr137 entirely to a 9.0-hour ground state of Ce137 was independently discovered. By allowed electron capture, Ce137 decays predominantly to a low-lying state of La137, with only a 3% branching to a 440-kev excited state. The 440-kev transition is at least predominantly E2 in character.A 34.4-hour isomeric state produced by the La139(p, 3n)Ce137m reaction decays by a 254.5-kev M4 transition to the 9-hour -ground state. A 0.6% branching was found from the isomeric state directly to a small group of apparently high spin states in La137.Studies of mass-separated isotopes confirmed the existence of 1.5-hour Pr137 and 1.0-hour Pr136. The K-capture to positron branching ratios observed in the decay of Pr139, Pr138, Pr137, and Pr136 show that these isotopes decay by allowed transitions to their cerium daughters. Characteristic gamma rays were observed.

THE DECAY OF Au193 AND LEVEL SCHEME OF Pt193

1957 ◽  
Vol 35 (5) ◽  
pp. 672-692 ◽  
Author(s):  
G. T. Ewan
Keyword(s):  
Excited State ◽  
Electron Capture ◽  
Level Scheme ◽  
Half Life ◽  
Internal Conversion ◽  
Upper Limit ◽  
First Excited State ◽  
Γ Rays ◽  
Γ Ray ◽  
Conversion Spectrum

Au193 has been produced as the daughter of Hg193 formed by the reaction Au197(p, 5n)Hg193 in the McGill synchrocyclotron. The internal conversion spectrum and unconverted γ-ray spectrum have been examined using β-ray spectrometers, Nal spectrometers, and coincidence techniques. Au193 decays by electron capture to Pt193 with a half-life of 17.5 ± 0.2 hr. An upper limit of 0.08% per disintegration has been placed on the probability of emission of positrons in this decay. Twenty-eight γ-rays, all below 500 kev., have been observed associated with the decay of Au193. The first excited state of Pt193 has been shown to be at 12.7 kev. and the lifetime of this state measured as (2.2 ± 0.8) × 10−9sec. A level scheme is proposed for Pt193.

scholarly journals Relative Intensity of the 17·2 and 14·3 MeV Gamma Rays from the 7Li(p,G)8Be Reaction

1960 ◽  
Vol 13 (2) ◽  
pp. 204 ◽  
Author(s):  
B Mainsbridge
Keyword(s):  
Excited State ◽  
Gamma Rays ◽  
Relative Intensity ◽  
Principal Components ◽  
Ground State ◽  
Intensity Ratio ◽  
Proton Capture ◽  
First Excited State

Radiation from proton capture in 7Li is known to consist of two principal components of energy (17�2+~.Ep) and (14'3+~Ep)MeV, corresponding to transitions to the ground state and first excited state of sBe respectively (Walker and McDaniel 1948). Resonances in the reaction are known to exist at Ep=441 keY, 1�03 and 2�1 MeV (Bonner and Evans 1948; Kraus 1954; Price 1954) and the relative intensity of the two y-rays is known to vary in the neighbourhood of the 441 keY resonance (Campbell 1956). It is not known if the intensity ratio varies in the region of the 1030 keY resonance and this experiment was designed to repeat the measurements of Campbell and extend the investigation to the higher resonance.

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