Decay mode, nuclides

Nuclide Half-life Decay mode Nuclide Half-life Decay mode... 

Half-life Principal Decay Mode Nuclide (yr) and Energy MeV) ... 

Information on isochronal annealing of Mo(CO)g has been given recently by Groening and Harbottle The most interesting result in this work was the clearly stepwise nature of the annealing, as is shown in Fig. 6. Curiously, not only the retention values but also the number and positions of the steps show isotropic differences. No clear explanation was offered other than the suggestion that the effect must arise from differences in the decay modes of the two excited nuclides. 

A detailed view of one portion of the N vs. Z plot of nuclides, illustrating the modes of nuclear decay for nuclides on either side of the belt of stability. 

Table 2. Half-lives for the U- and Th- decay series nuclides, with decay modes. 

Nuclide Symbol Mass Number Atomic Number Half-life3 Major Decay Mode"... 

G. W. C. Kaye and T. H. Laby, Tables of Physical and Chemical Constants, Longman 1995, gives a table of properties of the nuclides including isotopic abundance or half-life, decay modes, mass excess, neutron capture cross-section and ground-state spin and parity. This publication, with a prospect of regular updates, is available on the website http //www.kayelaby.npl.co.uk/. 

Detailed view of a portion of the Chart of the Nuclides. Stable isotopes are shaded. For stable nuclides, isotopic abundances are given below the element symbol and isotopic masses are given at the bottom of the square. Half-lives of the unstable nuclides are given, along with their decay modes. 

Nuclide Nr Half-life (years) Daughter isotope(s) Decay Stable nuclide mode N (Nr/Ns)o... 

The fact that there were three basic decay processes (and their names) was discovered by Rutherford. He showed that all three processes occur in a sample of decaying natural uranium (and its daughters). The emitted radiations were designated a, (3, and y to denote the penetrating power of the different radiation types. Further research has shown that in a decay, a heavy nucleus spontaneously emits a 4He nucleus (an a particle). The emitted a particles are monoenergetic, and, as a result of the decay, the parent nucleus loses two protons and two neutrons and is transformed into a new nuclide. All nuclei with Z > 83 are unstable with respect to this decay mode. 

Use the one-body theory of a decay to estimate the half-life of 224Ra for decay by emission of a 14C ion or a 4He ion. The measured half-life for the 14C decay mode is 10-9 relative to the 4He decay mode. Estimate the relative preformation factors for the a particle and 14C nucleus in the parent nuclide. 

Figure 11.15 Schematic representation of the mass yield distributions for the spontaneous fission of the trans-berkelium nuclides. (From D. C. Hoffman, et al., Spontaneous Fission in Nuclear Decay Modes, D. N. Poenaru, Ed. Copyright 1996 IOP Press. Reprinted by permission of IOP Press.)...

Nuclide tl/2 Decay Mode Amounts Available Specific Activity (dpm/p,g)... 

Nuclear reactions producing exotic nuclei at the limits of stability are usually very non-specific. For the fast and efficient removal of typically several tens of interfering elements with several hundreds of isotopes from the nuclides selected for study mainly mass separation [Han 79, Rav 79] and rapid chemical procedures [Her 82] are applied. The use of conventional mass separators is limited to elements for which suitable ion sources are available. There exists a number of elements, such as niobium, the noble metals etc., which create problems in mass separation due to restrictions in the diffusion-, evaporation- or ionization process. Such limitations do not exist for chemical methods. Although rapid off-line chemical methods are still valuable for some applications, continuously operated chemical procedures have been advanced recently since they deliver a steady source of activity needed for measurements with low counting efficiencies and for studies of rare decay modes. The present paper presents several examples for such techniques and reports briefly actual applications of these methods for the study of exotic nuclei. 

The two naturally occurring isotopes of copper are stable to nuclear decay. Nine synthetic radioisotopes have been reported ( Cu, Cu, Cu, Cu, Cu, Cu, Cu, " Cu, Cu) withhalf-hves of those nuclides ranging from 31 s ( Cu) to 2.58 days ( Cu). One isotope has been used for medical diagnostic purposes see Metal-based Imaging Agents) to scan the brain and to study Wilson s disease. This isotope, Cu, has a half-life of 12.7 h (decay modes at 0.571 MeV,... 

Radio- nuclide Production Decay mode and half-life [y] Production rate [atoms per m2 per y] Range of dating [y] Application... 

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