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Natural tritium
Author(s) -
Nir A.,
Kruger S. T.,
Lingenfelter R. E.,
Flamm E. J.
Publication year - 1966
Publication title -
reviews of geophysics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 8.087
H-Index - 156
eISSN - 1944-9208
pISSN - 8755-1209
DOI - 10.1029/rg004i004p00441
Subject(s) - cosmic ray , tritium , atmosphere (unit) , physics , solar flare , production rate , flare , environmental science , astrophysics , nuclear physics , meteorology , industrial engineering , engineering
The subject of natural tritium is reviewed from the inception of the search for this isotope in 1932 until the present. Three sources of natural tritium are considered: production in the atmosphere by galactic cosmic rays, production in the atmosphere by solar flare accelerated particles, and accretion from the sun. A recalculation of the cosmic‐ray production rate utilizing experimental data for the last solar cycle yields a worldwide average of 0.20 ± .09 triton/cm² sec during solar minimum and 0.16 ± .09 triton/cm² sec during solar maximum. Production of tritium by interaction of solar flare accelerated particles with the atmosphere is found to be less than 3% of the production by galactic cosmic rays. Calculations of the tritium decay rate from material balance, utilizing measured tritium concentrations of rain and ocean water corrected for synthetic tritium, are consistent within the limits of error with the production rate by galactic cosmic rays. The best estimate of the pre‐bomb inventory corresponds to a decay rate of 0.5 ± .3 triton/cm² sec as compared with the estimated production rate of 0.19 ± .09 triton/cm² sec. In view of the large errors it is not possible to determine whether appreciable amounts of tritium are accreted from the sun.