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Title: Half-life Measurements of Excited Levels in Fission Products around Mass Number 150

A spectrometer to measure nuclear level half-lives has been installed at the on-line isotope separator of the Kyoto University Reactor. This spectrometer consists of a LaBr3 scintillator, a thin plastic scintillator and an HPGe detector. Half-lives are deduced using the β-γ-γ delayed coincidence method. The prompt-time distribution curves measured with the spectrometer give a time resolution (FWHM) of 600 ps for 100-keV γ rays. This resolution means that half-lives down to the subnanosecond range or shorter can be measured. We reported recent measurements of the half-life of {sup 149}Pr and {sup 149}Nd. Some of the more interesting results include the first determination of the half-lives of {sup 149}Pr levels at 86.5 and 125.6 keV, which are 4.2(5) ns and 1.0(2) ns, respectively. In addition, the data indicate that the half-life of the 270.8-keV level in {sup 149}Nd is not 5.1(3) ns as reported previously, but 0.42(3) ns.
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [1]
  1. Radioisotope Research Center, Nagoya University, Nagoya 464-8602 (Japan)
  2. Graduate School of Engineering, Nagoya University, Nagoya 464-8603 (Japan)
  3. Institute of Health Biosciences, the University of Tokushima, Tokushima 770-8509 (Japan)
  4. Research Reactor Institute, Kyoto University, Kumatori 590-0494 (Japan)
Publication Date:
OSTI Identifier:
22436683
Resource Type:
Journal Article
Resource Relation:
Journal Name: Nuclear Data Sheets; Journal Volume: 120; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; COINCIDENCE METHODS; EXCITED STATES; FISSION PRODUCTS; HALF-LIFE; HIGH-PURITY GE DETECTORS; KEV RANGE 100-1000; KUR REACTOR; LANTHANUM BROMIDES; MASS NUMBER; NEODYMIUM 149; PRASEODYMIUM 149; SPECTROMETERS; TIME RESOLUTION