Selected Radioactive Isotopes

Decay modes are [latex]\alpha[/latex], [latex]{\beta }^{-}[/latex], [latex]{\beta }^{+}[/latex], electron capture (EC) and isomeric transition (IT). EC results in the same daughter nucleus as would [latex]{\beta }^{+}[/latex] decay. IT is a transition from a metastable excited state. Energies for [latex]{\beta }^{±}[/latex] decays are the maxima; average energies are roughly one-half the maxima.

Selected Radioactive Isotopes
Isotope t1/2 DecayMode(s) Energy(MeV) Percent [latex]\gamma[/latex]-Ray Energy(MeV) Percent
[latex]{\text{}}^{3}\text{H}[/latex] 12.33 y [latex]{\beta }^{-}[/latex] ­ 0.0186 100%
[latex]{\text{}}^{14}\text{C}[/latex] 5730 y [latex]{\beta }^{-}[/latex] 0.156 100%
[latex]{\text{}}^{13}\text{N}[/latex] 9.96 min [latex]{\beta }^{+}[/latex] 1.20 100%
[latex]{\text{}}^{22}\text{Na}[/latex] 2.602 y [latex]{\beta }^{+}[/latex] 0.55 90% [latex]\gamma[/latex] 1.27 100%
[latex]{\text{}}^{32}\text{P}[/latex] 14.28 d [latex]{\beta }^{-}[/latex] 1.71 100%
[latex]{\text{}}^{35}\text{S}[/latex] 87.4 d [latex]{\beta }^{-}[/latex] ­ 0.167 100%
[latex]{\text{}}^{36}\text{Cl}[/latex] [latex]3\text{.}\text{00}×{\text{10}}^{5}\text{y}[/latex] [latex]{\beta }^{-}[/latex] 0.710 100%
[latex]{\text{}}^{40}\text{K}[/latex] [latex]1\text{.}\text{28}×{\text{10}}^{9}\text{y}[/latex] [latex]{\beta }^{-}[/latex] 1.31 89%
[latex]{\text{}}^{43}\text{K}[/latex] 22.3 h [latex]{\beta }^{-}[/latex] 0.827 87% [latex]\gamma \phantom{\rule{0.10em}{0ex}}\text{s}[/latex] 0.373 87%
0.618 87%
[latex]{\text{}}^{45}\text{Ca}[/latex] 165 d [latex]{\beta }^{-}[/latex] ­ 0.257 100%
[latex]{\text{}}^{51}\text{Cr}[/latex] 27.70 d EC [latex]\gamma[/latex] 0.320 10%
[latex]{\text{}}^{52}\text{Mn}[/latex] 5.59d [latex]{\beta }^{+}[/latex] 3.69 28% [latex]\gamma \phantom{\rule{0.10em}{0ex}}\text{s}[/latex] 1.33 28%
1.43 28%
[latex]{\text{}}^{52}\text{Fe}[/latex] 8.27 h [latex]{\beta }^{+}[/latex] 1.80 43% 0.169 43%
0.378 43%
[latex]{\text{}}^{59}\text{Fe}[/latex] 44.6 d [latex]{\beta }^{-}\text{s}[/latex] 0.273 45% [latex]\gamma \phantom{\rule{0.10em}{0ex}}\text{s}[/latex] 1.10 57%
0.466 55% 1.29 43%
[latex]{\text{}}^{60}\text{Co}[/latex] 5.271 y [latex]{\beta }^{-}[/latex] ­ 0.318 100% [latex]\gamma \phantom{\rule{0.10em}{0ex}}\text{s}[/latex] 1.17 100%
1.33 100%
[latex]{\text{}}^{65}\text{Zn}[/latex] 244.1 d EC [latex]\gamma[/latex] 1.12 51%
[latex]{\text{}}^{67}\text{Ga}[/latex] 78.3 h EC [latex]\gamma \phantom{\rule{0.10em}{0ex}}\text{s}[/latex] 0.0933 70%
0.185 35%
0.300 19%
others
[latex]{\text{}}^{75}\text{Se}[/latex] 118.5 d EC [latex]\gamma \phantom{\rule{0.10em}{0ex}}\text{s}[/latex] 0.121 20%
0.136 65%
0.265 68%
0.280 20%
others
[latex]{\text{}}^{86}\text{Rb}[/latex] 18.8 d [latex]{\beta }^{-}\text{s}[/latex] 0.69 9% [latex]\gamma[/latex] 1.08 9%
1.77 91%
[latex]{\text{}}^{85}\text{Sr}[/latex] 64.8 d EC [latex]\gamma[/latex] 0.514 100%
[latex]{\text{}}^{90}\text{Sr}[/latex] 28.8 y [latex]{\beta }^{-}[/latex] ­ 0.546 100%
[latex]{\text{}}^{90}\text{Y}[/latex] 64.1 h [latex]{\beta }^{-}[/latex] ­ 2.28 100%
[latex]{\text{}}^{99m}\text{Tc}[/latex] 6.02 h IT [latex]\gamma[/latex] 0.142 100%
[latex]{\text{}}^{113m}\text{In}[/latex] 99.5 min IT [latex]\gamma[/latex] 0.392 100%
[latex]{\text{}}^{123}\text{I}[/latex] 13.0 h EC [latex]\gamma[/latex] 0.159 [latex]\text{≈100%}\text{}[/latex]
[latex]{\text{}}^{131}\text{I}[/latex] 8.040 d [latex]{\beta }^{-}\text{s}[/latex] 0.248 7% [latex]\gamma \phantom{\rule{0.10em}{0ex}}\text{s}[/latex] 0.364 85%
0.607 93% others
others
[latex]{\text{}}^{129}\text{Cs}[/latex] 32.3 h EC [latex]\gamma \phantom{\rule{0.10em}{0ex}}\text{s}[/latex] 0.0400 35%
0.372 32%
0.411 25%
others
[latex]{\text{}}^{137}\text{Cs}[/latex] 30.17 y [latex]{\beta }^{-}\text{s}[/latex] ­ 0.511 95% [latex]\gamma[/latex] 0.662 95%
1.17 5%
[latex]{\text{}}^{140}\text{Ba}[/latex] 12.79 d [latex]{\beta }^{-}[/latex] 1.035 [latex]\text{≈100%}\text{}[/latex] [latex]\gamma \phantom{\rule{0.10em}{0ex}}\text{s}[/latex] 0.030 25%
0.044 65%
0.537 24%
others
[latex]{\text{}}^{198}\text{Au}[/latex] 2.696 d [latex]{\beta }^{-}[/latex] ­ 1.161 [latex]\text{≈100%}\text{}[/latex] [latex]\gamma[/latex] 0.412 [latex]\text{≈100%}\text{}[/latex]
[latex]{\text{}}^{197}\text{Hg}[/latex] 64.1 h EC [latex]\gamma[/latex] 0.0733 100%
[latex]{\text{}}^{210}\text{Po}[/latex] 138.38 d [latex]\alpha[/latex] 5.41 100%
[latex]{\text{}}^{226}\text{Ra}[/latex] [latex]1\text{.}\text{60}×{\text{10}}^{3}\text{y}[/latex] [latex]\alpha \text{s}[/latex] 4.68 5% [latex]\gamma[/latex] 0.186 100%
4.87 95%
[latex]{\text{}}^{235}\text{U}[/latex] [latex]7\text{.}\text{038}×{\text{10}}^{8}\text{y}[/latex] [latex]\alpha[/latex] 4.68 [latex]\text{≈100%}\text{}[/latex] [latex]\gamma \phantom{\rule{0.10em}{0ex}}\text{s}[/latex] numerous <0.400%
[latex]{\text{}}^{238}\text{U}[/latex] [latex]4\text{.}\text{468}×{\text{10}}^{9}\text{y}[/latex] [latex]\alpha \text{s}[/latex] 4.22 23% [latex]\gamma[/latex] 0.050 23%
4.27 77%
[latex]{\text{}}^{237}\text{Np}[/latex] [latex]2\text{.}\text{14}×{\text{10}}^{6}\text{y}[/latex] [latex]\alpha \text{s}[/latex] numerous [latex]\gamma \phantom{\rule{0.10em}{0ex}}\text{s}[/latex] numerous <0.250%
4.96 (max.)
[latex]{\text{}}^{239}\text{Pu}[/latex] [latex]2\text{.}\text{41}×{\text{10}}^{4}\text{y}[/latex] [latex]\alpha \text{s}[/latex] 5.19 11% [latex]\gamma \phantom{\rule{0.10em}{0ex}}\text{s}[/latex] [latex]7\text{.}5×{\text{10}}^{-5}[/latex] 73%
5.23 15% 0.013 15%
5.24 73% 0.052 10%
others
[latex]{\text{}}^{243}\text{Am}[/latex] [latex]7\text{.}\text{37}×{\text{10}}^{3}\text{y}[/latex] [latex]\alpha \text{s}[/latex] Max. 5.44 [latex]\gamma \phantom{\rule{0.10em}{0ex}}\text{s}[/latex] 0.075
5.37 88% others
5.32 11%
others

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