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This document presents results of an investigation of the material and geometry choice for the transport shield of germanium, the active detector material used in 76Ge neutrinoless double beta decay searches. The objective of this...
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This document presents results of an investigation of the material and geometry choice for the transport shield of germanium, the active detector material used in 76Ge neutrinoless double beta decay searches. The objective of this work is to select the optimal material and geometry to minimize cosmogenic production of radioactive isotopes in the germanium material. The design of such a shield is based on the calculation of the cosmogenic production rate of isotopes that are known to cause interfering backgrounds in 76Ge neutrinoless double beta decay searches.
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The average beta and gamma energies in the decay of 382 known fission products have been determined. As far as possible the values are based on experimental data: direct determinations, published decay schemes, and a study of beta...
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The average beta and gamma energies in the decay of 382 known fission products have been determined. As far as possible the values are based on experimental data: direct determinations, published decay schemes, and a study of beta strength functions. In cases for which no experimental data exist the average energies have been derived using extrapolated beta strength functions. (Atomindex citation 10:460359)
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We compute the spectrum of (beta)-decay, assuming that (Majorana or Dirac) neutrinos propagate in constant potentials. We study the modifications of the spectrum due to the effect of these potentials. Data on tritium decay and on ...
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We compute the spectrum of (beta)-decay, assuming that (Majorana or Dirac) neutrinos propagate in constant potentials. We study the modifications of the spectrum due to the effect of these potentials. Data on tritium decay and on (sup 3)H-(sup 3)He mass difference allow us to infer bounds in the electronvolts range on the potentials. (author). 9 refs, 1 fig. (Atomindex citation 28:069718)
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A review of recent results on branching fractions and time-integrated CP asymmetries of rare B(sub u) and B(sub d) decays to mesonic final states from BABAR Belle and CLEO experiments is presented.
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The beta spectrum of the decay of free molecular tritium has been accurately measured in order to search for a finite anti nu/sub e/ mass. The betas originating from the decay of free tritium molecules in a differentially pumped s...
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The beta spectrum of the decay of free molecular tritium has been accurately measured in order to search for a finite anti nu/sub e/ mass. The betas originating from the decay of free tritium molecules in a differentially pumped source region were momentum analyzed in a toroidal beta spectrometer with 36-eV resolution. The final state effects in molecular tritium are accurately known and the data thus allow us to set an upper limit of 29.3 eV on the anti nu/sub e/ mass at the 95% confidence level. (ERA citation 11:055305)
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Tables and graphs are given of beta-ray dose distributions near isotropic point and plane beta sources in water and air, for 95 nuclides of importance in medicine and radiation protection. These are calculated from Spencer's dose-...
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Tables and graphs are given of beta-ray dose distributions near isotropic point and plane beta sources in water and air, for 95 nuclides of importance in medicine and radiation protection. These are calculated from Spencer's dose-distribution tables for monoenergetic electrons and from recent nuclear decay data. Information is given for determining dose distributions in other low-Z media. (Atomindex citation 15:004875)
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In the last decade, a variety of neutrino oscillation experiments have established that there is a mass difference between neutrino flavors, without determining the absolute neutrino mass scale. The Enriched Xenon Observatory for ...
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In the last decade, a variety of neutrino oscillation experiments have established that there is a mass difference between neutrino flavors, without determining the absolute neutrino mass scale. The Enriched Xenon Observatory for neutrinoless double beta decay (EXO) will search for the rare decays of xenon to determine the absolute value of the neutrino mass. The experiment uses a novel technique to minimize backgrounds, identifying the decay daughter product in real time using single ion spectroscopy. Here, we describe single ion trapping and spectroscopy compatible with the EXO detector. We extend the technique of single ion trapping in ultrahigh vacuum to trapping in xenon gas. With this technique, EXO will achieve a neutrino mass sensitivity of (approximately equal) .010 eV.
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The results of a review and evaluation of neutron and non-neutron nuclear data published in the scientific literature are presented. The status of new chemical elements is examined. Data on revised values for the isotopic composit...
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The results of a review and evaluation of neutron and non-neutron nuclear data published in the scientific literature are presented. The status of new chemical elements is examined. Data on revised values for the isotopic composition of the elements are reviewed and recommended values are presented. Half-lives of very long-lived nuclides are presented, including double beta decay, double electron capture, long-lived alpha decay and long-lived beta decay. Data from new measurements on the very heavy elements (trans-meitnerium elements) are discussed and tabulated. The first observation of the radioactive decay mode of the free neutron is discussed. New measurements that have expanded the neutron drip line for magnesium and aluminum are discussed. Data on recent neutron cross-section and resonance integral measurements are also discussed.
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Fireman(1) has reported the results of a rather difficult beta-particle coincidence counting experiment in which the decay of Sn{sup 124} by the simultaneous emission of two negative beta-particles, with a half-life between 0.4 x ...
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Fireman(1) has reported the results of a rather difficult beta-particle coincidence counting experiment in which the decay of Sn{sup 124} by the simultaneous emission of two negative beta-particles, with a half-life between 0.4 x 10{sup 16} years and 0.9 x 10{sup 16} years, seems to have been observed. This note reports the results obtained from a different and somewhat simpler method of looking for the phenomenon of simultaneous emission of two beta-particles. These results are negative so far and show that this process is considerably less probable in the case chosen by us than in that reported by Fireman. The method consists of looking in uranium samples for 90-year Pu{sup 238} which would come from U{sup 238} by the double beta-particle mechanism since Np{sup 238} is heavier than U{sup 238}, which in turn is substantially heavier than Pu{sup 238}, in the isobaric triplet {sub 92}U{sup 238}-{sub 93}Np{sup 238}-{sub 94}Pu{sup 238}. This chemical method of investigation is particularly applicable to this isobaric triplet because there appears to be no other mechanisms to account for the Pu{sup 238} should it be found. The energetics of the situation are summarized in the following diagram, where the disintegration energies are derived from sources which may be traced through a recent compilation.
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