Internal Bremsstrahlung and Ionization Accompanying Beta Decay
TL;DR: In this article, the theoretical internal bremsstrahlung spectrum of RaE was calculated by using both the observed forbidden beta spectrum and an allowed beta distribution, and the agreement between the theoretical and experimental results was considered satisfactory.
Abstract: Internal bremsstrahlung spectra from S35 and Pm147 have been investigated with the NaI scintillation spectrometer. Both the absolute cross section of production and the energy distribution agree with theoretical predictions. The theoretical internal bremsstrahlung spectrum of RaE was calculated by using both the observed forbidden beta spectrum and an allowed beta distribution. No significant differences in shape were found in these two cases except in the absolute cross section of production.
The ionization accompanying beta decay was studied in the case of RaE and also in Pm147 by measuring the characteristic x-rays in an NaI scintillation counter as well as in a proportional counter spectrometer. Both K and L radiations were observed, and their absolute cross sections were compared with the theoretical calculations of Migdal, Feinberg, and Levinger. Because of the approximate nature of the theoretical calculations, the agreement between the theoretical and experimental results is considered satisfactory.
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01 Jan 2020
TL;DR: In this paper, a history of the discovery and characterization of radioactivity is described, and a description of the properties of atomic constituents, and the relation between mass and energy is discussed.
Abstract: The chapter includes a history of the discovery and characterization of radioactivity. It follows with a description of the properties of atomic constituents, and the relation between mass and energy. This is followed with a treatment on the properties of the nucleus, nuclear forces, binding energy, nuclear models, and the relativistic properties of nuclear radiation. Natural and artificially produced radionuclides are discussed including radionuclides of cosmogenic origin and natural radionuclide decay chains. Nuclear reactions are discussed including reaction types, energy of reactions (Q value), and reaction cross section. A treatment of alpha decay, beta decay including negatron emission, positron emission, electron capture (EC), double beta (ββ) decay, and the interactions of alpha and beta radiation with matter. Also discussed are internal conversion and Auger electron emissions and a detailed treatment of neutron sources, interaction of neutrons with matter, neutron attenuation and cross section, and neutron decay. The wave-particle dual nature of matter is discussed and a treatment of electromagnetic radiation or photons including the mechanisms of photon interaction with matter. Cherenkov radiation, its origin, and properties are discussed. The origins, properties and applications of synchrotron radiation are also discussed. The chapter continues with a treatment of nuclear recoil and the calculations of recoil energy following alpha, beta, gamma, X-ray, and neutrino emission in radionuclide decay. Cosmic radiation is discussed including the origins, properties, classification, and showers of the cosmic radiation. A treatment of radiation dose, stopping power, and linear energy transfer is included. The principles of radionuclide decay, ingrowth, and equilibrium are included. There is also a discussion of radioactivity units and the correlation of radioactivity and radionuclide mass.
23 citations
01 Jan 2012
TL;DR: In this paper, a brief history of the discovery and early characterization of radioactivity is described together with the properties of atomic constituents, the distinction between nuclides, isotopes, isobars, isomers and isotones, and the relation between mass and energy.
Abstract: The chapter begins with a brief history of the discovery and early characterization of radioactivity. It follows with a description of basic units and definitions together with the properties of atomic constituents, the distinction between nuclides, isotopes, isobars, isomers and isotones, and the relation between mass and energy. This preliminary material is followed with a treatment on the properties of the nucleus, nuclear forces, binding energy, and nuclear models. Natural and artificially produced radionuclides are then discussed in detail including radionuclides of cosmogenic origin and natural radionuclide decay chains. Nuclear reactions are subsequently discussed including reaction types, energy of reactions ( Q value), and reaction cross section. Following is a detailed treatment of alpha decay, beta decay including negatron emission, positron emission, electron capture (EC), double beta ( ββ ) decay, and the interactions of alpha and beta radiation with matter. Other decay processes discussed are internal conversion and Auger electron emissions followed by a detailed treatment of neutron radiation including neutron sources, interaction of neutrons with matter, neutron attenuation and cross section, and neutron decay. The wave–particle dual nature of matter is discussed followed by a detailed treatment of electromagnetic radiation or photons including the mechanisms of photon interaction with matter. Cherenkov radiation, its origin, and properties are discussed. The chapter continues with a treatment of nuclear recoil and the calculations of recoil energy following alpha-, beta-, gamma-, x-ray-, and neutrino-emission in radionuclide decay. Cosmic radiation is discussed in detail including the origins, properties, classification, and showers of the cosmic radiation. A brief treatment of radiation dose, stopping power, and linear energy transfer is included. The principles of radionuclide decay, ingrowth, and equilibrium are dealt with in detail. The chapter concludes with a treatment of radioactivity units and the correlation of radioactivity and radionuclide mass.
19 citations
TL;DR: In this paper, the model for auto-ionization in the K-shell is extended to the L-shell and the comparison between the calculated and available experimental results is not as straightforward as for the k-shell case, due to complications arising from fluorescence yields and Coster-Kronig vacancy shifting probabilities.
18 citations
TL;DR: In this article, the total intensity of fluorescentL X-rays that follow the photoelectric absorption of a known flux of γ-rays in the L-shell was measured using a proportional counter.
Abstract: L-shell photoelectric cross-sections for mercury, gold, thallium, lead, bismuth, thorium and uranium at 145 and 279 keV energies have been determined via two methods. The technique employed involves measurement of the total intensity of fluorescentL X-rays that follow the photoelectric absorption of a known flux of γ-rays in theL-shell. A proportional counter has been used as a fluorescentL X-ray detector. The results are in good agreement with the theoretical predictions of Schmickley and Pratt.
17 citations
TL;DR: In this article, the total probability of a K-shake-off process in β-decay has been reformulated by correcting the theory by Law and Campbell and adding simple corrections for the k-shakeup contribution and for the correlation effect between K electron and other bound electrons.
Abstract: The total probability of aK-shake-off process in β-decay has been reformulated by correcting the theory by Law and Campbell. By means of the improved formulation and by adding simple corrections for theK-shake-up contribution and for the correlation effect betweenK electron and other bound electrons, the totalK hole creation probability per β-decay has been evaluated for 24 interesting nuclides. There exist distinct disagreements between our calculated values and recent experimental data; the measured probabilities are systematically larger than our calculated ones for medium- and high-Z nuclides. This clearly indicates that the theory ofK shake-off, as here corrected, is not sufficient to explain the recent experimental data. This is contrary to the conclusion recently presented by many other workers that theK-shake-off plus shake-up process is the predominant mechanism ofK-shell internal ionization and excitation in β-decay. It will be necessary to introduce the β-particleelectron correlation in future theoretical treatments.
16 citations