The radioactive decay series 138Nd → 138Pr → 138Ce

1970 ◽  
Vol 48 (14) ◽  
pp. 2151-2157 ◽  
Author(s):  
James J. Hogan
Keyword(s):  
Direct Measurement ◽  
Gamma Rays ◽  
Radioactive Decay ◽  
Excited Level ◽  
Branching Ratio ◽  
Decay Chain ◽  
Decay Series

Measurements of the energies and intensities of gamma rays associated with decay of 138Nd, 138Prm, and 138Prg have been performed using a Ge(Li) detector. The branching ratio to a previously unreported excited level of 138Pr (328.1 keV) has been measured, thus allowing for direct measurement of the decay of 138Nd. Half-lives of 2.20 ± 0.07 and 5.04 ± 0.09 h have been measured for 138Prm and 138Nd, respectively. Decay schemes for 138Prm → 138Ce and for the decay chain 138Nd → 138Prg → 138Ce are proposed.

15.—Natural Radioactive Decay Series Elements in the Oceans and Sediments

1972 ◽  
Vol 72 (1) ◽  
pp. 167-182 ◽  
Author(s):  
J Thomson ◽  
A. Walton
Keyword(s):  
Radioactive Decay ◽  
Decay Chain ◽  
Secular Equilibrium ◽  
Marine Geochemistry ◽  
Daughter Nuclide ◽  
Decay Products ◽  
Naturally Occurring ◽  
Decay Series ◽  
Time Required ◽  
Radio Isotopes

The parents of the three naturally occurring radioactive decay series (text-fig. 1),232Th, 238U and 235U, have existed since the time of formation of the earth and through the process of radioactive decay have continuously generated their shorterlived daughter radio-isotopes. Under conditions where these decay products are not separated from the parents the situation referred to as secular equilibrium may be attained at which the activity ratio of any two daughters in the same decay chain is unity. The time required for the attainment of this situation corresponds to several half-lives of the longest lived daughter nuclide. In a great many instances, however, secular equilibrium is not achieved. Excellent examples of disequilibrium are to be found in the distribution of natural radioactive decay series elements in the oceans and sediments. These situations can be used to advantage in marine geochemistry to obtain information on residence times of elements in the oceans and rates of sedimentation occurring under a variety of conditions.

scholarly journals DECSERVIS: a tool for radioactive decay series visualisation

2006 ◽  
Vol 4 (4) ◽  
pp. 822-834 ◽  
Author(s):  
Saad Azzam ◽  
Juhani Suksi
Keyword(s):  
Initial Conditions ◽  
Radioactive Decay ◽  
Decay Chain ◽  
Decay Series ◽  
Closed Systems ◽  
Natural Decay ◽  
User Friendly ◽  
Interactive Visualisation ◽  
Flexible Operation ◽  
Chain Decay

AbstractWe have developed an interactive visualisation tool, decay series visualisation (DECSERVIS), for exploring the three natural radioactive decay chains. Through DECSERVIS, one can investigate the full decay scheme of any natural decay chain radionuclide to obtain the number of nuclides, their masses, activities, and activity ratios, accounting for all the daughters, starting from initial conditions freely chosen by the user. The tool has been developed particularly for user friendly and flexible operation. Chain decay in closed systems can be explored as a function of time with various graphical presentations such as solid curve and column diagrams or animation. We present several exploration examples related to geological dating. DECSERVIS will be freely available on request.

Sur la Mise en Evidence de Faibles Branches β dans la Désintégration de 77As

1971 ◽  
Vol 49 (13) ◽  
pp. 1731-1737 ◽  
Author(s):  
G. Ardisson ◽  
C. Marsol
Keyword(s):  
Gamma Rays ◽  
Level Scheme ◽  
Branching Ratio ◽  
Coincidence Spectra

The decay of 77As was reinvestigated by means of a Ge(Li) detector, γ–γ coincidences and sum coincidence spectra were also measured with a Ge(Li)–NaI(Tl) assembly. Five new gamma rays are observed at 62.2, 82.0, 139.2, 200.6, and 439.7 keV, which are situated in a revised level scheme of 77Se. An anomalous 5/2+ level of 301 keV, seen in 76Se(d,p)77Se experiments, is suggested to be fed in the decay of 77As, with a branching ratio of 0.014%. The 440 keV (5/2−) collective level is also fed by 0.001% of the decays.

Simultaneous resolution of reactive radioactive decay, non-isothermal flow, and migration with application to the performance assessment for HLW repositories

2010 ◽  
Vol 98 (6) ◽  
Author(s):  
R. Juncosa ◽  
I. Font ◽  
J. Delgado
Keyword(s):  
Ion Exchange ◽  
Radioactive Decay ◽  
Chemical Species ◽  
High Level Waste ◽  
Chemical Components ◽  
Clay Material ◽  
Decay Series ◽  
And Migration ◽  
High Level ◽  
Radioactive Species

AbstractRadioactive decay is an important subject to take into account when studying the thermo-hydro-dynamic behavior of the buffer clay material used in the containment of radioactive waste. The modern concepts for the multibarrier design of a repository of high level waste in deep geologic formations consider that once canisters have failed, the buffer clay material must ensure the retention and/or delay of radionuclides within the time framework given in the assessment studies. Within the clay buffer, different chemical species are retarded/fixed according to several physicochemical processes (ion exchange, surface complexation, precipitation, matrix diffusion, ...) but typical approaches do not consider the eventuality that radioactive species change their chemical nature (The radioactive decay of an element takes place independently of the phase (aqueous, solid or gaseous) to which it belongs. This means that, in terms of radionuclide fixation, some geochemical processes will be effective scavengers (for instance mineral precipitation of crystal growth) while others will not (for instance ion exchange and/or sorption).In this contribution we present a reactive radioactive decay model of any number of chemical components including those that belong to decay series. The model, which is named FLOW-DECAY, also takes into account flow and isotopic migration and it has been applied considering a hypothetical model scenario provided by the project ENRESA 2000 and direct comparison with the results generated by the probabilistic code GoldSim. Results indicate that FLOW-DECAY may simulate the decay processes in a similar way that GoldSim, being the differences related to factors associated to code architecture.

Investigation of gamma rays in the decay chain

1967 ◽  
Vol 106 (2) ◽  
pp. 275-288 ◽  
Author(s):  
I. Adam ◽  
K.S. Toth ◽  
R.A. Meyer
Keyword(s):  
Gamma Rays ◽  
Decay Chain

The Decay of 169Yb

1972 ◽  
Vol 50 (19) ◽  
pp. 2348-2354 ◽  
Author(s):  
S. K. Sen ◽  
D. L. Salie ◽  
E. Tomchuk
Keyword(s):  
Direct Measurement ◽  
Gamma Rays ◽  
Internal Conversion ◽  
Gamma Ray ◽  
Conversion Coefficient ◽  
Coulomb Excitation ◽  
Internal Conversion Coefficient ◽  
Electron Capture Decay ◽  
Upper Limits ◽  
First Time

The decay of 169Yb was investigated using several Ge(Li) detectors of different sizes. The following gamma rays (energies in keV and intensities within brackets) were definitely identified with the 169Yb decay: 20.7 (0.66 ± 0.04), 63.1 (124 ± 5), 93.6 (7.2 ± 0.3), 109.8 (50 ± 2), 117.3 (0.08 ± 0.04), 118.2 (5.4 ± 0.2), 130.5 (34 ± 2), 156.7 (0.023 ± 0.004), 177.2(59 ± 3), 198.0 (100), 240.4 (0.33 ± 0.02), 261.0 (4.7 ± 0.2), and 307.7 (28 ± 1). The recently reported weak gamma-ray peaks at 515 (0.008 ± 0.002) and 625 (0.010 ± 0.002) were also observed and could not be ruled out as not belonging to 169Yb. The recently reported gamma-ray peaks at 140, 160, 207, 288, 295, 316, 320, 328, 355, 371, 379, 396, and 417 were detected and shown not to be from the decay of 169Yb while those at 218, 229, 285, 304, 335, 388, 411, and 425 were not observed and upper limits were placed on their intensities. The presence of very weak peaks at 515 and 625 establishes the formation of the 633 keV state of 169Tm following electron capture decay of 169Yb as reported by George. (This level has been previously observed only in Coulomb excitation of 169Tm.) The total internal conversion coefficient for the 20.7 keV transition was determined for the first time from the direct measurement of the gamma-ray intensity as 51 ± 10 corresponding to an M1 transition.

scholarly journals Radon content in Danish till deposits: relationship with redox conditions and age

1969 ◽  
Vol 20 ◽  
pp. 39-42
Author(s):  
Peter Gravesen ◽  
Peter Roll Jakobsen
Keyword(s):  
Water Content ◽  
Clay Minerals ◽  
Organic Material ◽  
Half Life ◽  
Radioactive Decay ◽  
Decay Chain ◽  
Redox Conditions ◽  
Transport Rate ◽  
Radon Content

Radon (222Rn) is a radioactive, noble insoluble gas with a half-life of 3.8 days. It belongs to the uranium (238U) decay chain where radon is formed from radium (226Ra). Uranium and radium are built into mineral structures or are, for example, adsorbed on the surface of clay minerals, limonite or organic material. When radon is formed by radioactive decay from radium, parts of it enter the pores of rocks and soils and are transported by diffusive or advective forces in the pores. The transport rate depends on the permeability and water content in the pores (Nazaroff 1992).

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