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M. P.
Unterweger,1 D. D. Hoppes,1 F. J.
Schima,1, and J. S. Coursey2 |
1National Institute of Standards and Technology, Physics
Laboratory, Ionizing Radiation Division
2NIST, Physics Laboratory, Office of Electronic Commerce in
Scientific and Engineering Data |
The half lives of many radionuclides have been measured in the Radioactivity
Group of NIST. The table below, based on "New and revised half-life
measurements results,"§ by
M.P. Unterweger, D.D. Hoppes, and F.J. Schima (1992), is a revised listing of
the half lives determined at NIST since 1967. This table supersedes the table
presented in NBS Special Publication 626 [D.D. Hoppes and
F.J. Schima, ed. (1982), p. 85] as well as that presented
in "New and revised half-life measurements results." Included in this
table are new values not previously tabulated in either publication. The
references are given for these values. Values revised since NBS Special
Publication 626 for the half lives of various "short-lived"
radionuclides arise from improved impurity analysis, incorporation of
additional data from new sources, and reevaluation of old data.
Values in common usage in certificates and reports are available from the
National Nuclear Data Center.
In case of discrepant data, the NIST value is recommended.
ASCII table (good for cutting and
pasting)
Radionuclide |
Number of Sources |
Number of Half Lives Followed |
Half Life* |
Statistical Standard Uncertainty |
Other Standard Uncertainty |
Reference |
|
3H | 18 | 3 | 4500 ± 8 d | 8 | 0 | 1 (a) |
18F | 3 | 13.1 | 1.82951 ± 0.00034 h | 0.00024 | 0.00024 | § |
22Na | 5 | 1.9 - 4.7 | 950.97 ± 0.15 d | 0.09 | 0.12 | § |
24Na | 14 | 1.1 - 7.6 | 14.9512 ± 0.0032 h | 0.0009 | 0.0031 | § |
32P | 2 | 2.8 | 14.263 ± 0.003 d | 0.003 | 0.0 | 6 |
44Ti | 1 | 0.35 | 22154 ± 456 d | 180 | 419 | 2 |
46Sc | 4 | 3.6 - 10.3 | 83.831 ± 0.066 d | 0.030 | 0.059 | § |
51Cr | 11 | 2.3 - 8.9 | 27.7010 ± 0.0012 d | 0.0007 | 0.0009 | § |
54Mn | 2 | 3.3 - 7.4 | 312.028 ± 0.034 d | 0.034 | 0.0 | § |
57Co | 7 | 4.7 - 10.4 | 272.11 ± 0.26 d | 0.09 | 0.25 | § |
58Co | 1 | 9.1 | 70.77 ± 0.11 d | 0.11 | 0.0 | § |
59Fe | 6 | 4.0 - 9.3 | 44.5074 ± 0.0072 d | 0.0048 | 0.0053 | § |
60Co | 8 | 3.7 - 5.3 | 1925.20 ± 0.25 d | 0.10 | 0.23 | §,6 |
62Cu | 3 | 2.7 - 3.9 | 9.6725 ± 0.0080 min | 0.0080 | 0.0 | 3,6 |
65Zn | 1 | 3.2 | 244.164 ± 0.099 d | 0.099 | 0.0 | § |
67Ga | 13 | 1.8 - 8.3 | 3.26154 ± 0.00054 d | 0.00015 | 0.00052 | § |
75Se | 19 | 2.4 - 8.7 | 119.809 ± 0.066 d | 0.014 | 0.065 | § |
85Kr | 1 | 1.9 | 3935.7 ± 1.2 d | 1.2 | 0.0 | §,6 |
85Sr | 8 | 1.1 - 4.8 | 64.8530 ± 0.0081 d | 0.0039 | 0.0071 | § |
88Y | 8 | 1.3 - 8.1 | 106.626 ± 0.044 d | 0.017 | 0.041 | § |
99Mo | 14 | 3.6 - 9.5 | 65.9239 ± 0.0058 h | 0.0031 | 0.0049 | § |
99mTc | 33 | 2.1 - 12.0 | 6.00718 ± 0.00087 h | 0.00015 | 0.00086 | § (b) |
99mTc | 17 | 1.9 - 8.0 | 6.0123 ± 0.0032 h | 0.0007 | 0.0031 | 6 (c) |
103Ru | 7 | 0.4 | 39.310 ± 0.044 d | 0.044 | 0.0 | 6 |
109Cd | 2 | 3.4 - 5.3 | 463.26 ± 0.63 d | 0.36 | 0.51 | § |
110mAg | 1 | 9.3 | 249.950 ± 0.024 d | 0.024 | 0.0 | § |
111In | 11 | 1.4 - 9.3 | 2.80477 ± 0.00053 d | 0.00017 | 0.00051 | § |
113Sn | 11 | 2.3 - 11.0 | 115.079 ± 0.080 d | 0.025 | 0.076 | § |
117mSn | 10 | 1.5 - 4.0 | 14.00 ± 0.05 d | 0.05 | 0.0 | 4 |
123I | 3 | 5.4 - 12.7 | 13.2235 ± 0.0019 h | 0.0019 | 0.0 | § |
125I | 18 | 1.4 - 6.2 | 59.49 ± 0.13 d | 0.03 | 0.12 | § |
125Sb | 1 | 5.4 | 1007.56 ± 0.10 d | 0.10 | 0.0 | §,6 |
127Xe | 5 | 1.1 - 11.5 | 36.3446 ± 0.0028 d | 0.0028 | 0.0 | § |
131I | 21 | 1.0 - 10.9 | 8.0197 ± 0.0022 d | 0.0005 | 0.0021 | § |
131mXe | 2 | 1.8 | 11.934 ± 0.021 d | 0.014 | 0.016 | § |
133Ba | 4 | 2.0 | 3854.7 ± 2.8 d | 1.3 | 2.5 | §,6 |
133Xe | 3 | 4.8 - 11.2 | 5.24747 ± 0.00045 d | 0.00045 | 0.0 | § |
134Cs | 5 | 1.7 - 3.0 | 753.88 ± 0.15 d | 0.11 | 0.11 | § |
137Cs | 6 | 0.7 - 0.9 | 11018.3 ± 9.5 d | 3.5 | 8.8 | §,6 |
139Ce | 9 | 1.5 - 6.4 | 137.734 ± 0.091 d | 0.029 | 0.086 | § |
140Ba | 10 | 1.8 - 4.4 | 12.7527 ± 0.0023 d | 0.0009 | 0.0022 | § |
140La | 2 | 4.2 | 40.293 ± 0.012 h | 0.008 | 0.009 | § |
141Ce | 1 | 6.1 | 32.510 ± 0.024 d | 0.024 | 0.0 | § |
144Ce | 1 | 3.9 | 284.534 ± 0.032 d | 0.032 | 0.0 | §,6 |
152Eu | 4 | 1.6 - 1.8 | 4947.2 ± 1.1 d | 0.7 | 0.8 | §,6 |
153Gd | 2 | 7.3 | 239.472 ± 0.069 d | 0.041 | 0.055 | § |
153Sm | 1 | 7.3 | 46.2853 ± 0.0014 h | 0.0014 | 0.0 | § |
154Eu | 3 | 2.4 | 3145.2 ± 1.1 d | 1.1 | 0.0 | §,6 |
155Eu | 2 | 3.1 - 4.3 | 1739.06 ± 0.45 d | 0.45 | 0.0 | §,6 |
166Ho | 2 | 5.4 - 7.2 | 26.794 ± 0.023 h | 0.013 | 0.019 | §,6 |
169Yb | 14 | 3.4 - 9.5 | 32.0147 ± 0.0093 d | 0.0026 | 0.0089 | § |
177Lu | 4 | 2 - 5 | 6.64 ± 0.01 d | 0.01 | 0.0 | 5 |
181W | 3 | 5.9 - 6.6 | 121.095 ± 0.064 d | 0.042 | 0.048 | § |
186Re | 2 | 5.7 - 6.5 | 89.248 ± 0.069 h | 0.018 | 0.067 | § |
188Re | 3 | 4.2 - 7.1 | 17.001 ± 0.022 h | 0.09 | 0.021 | §,6 |
188W | 1 | 4.0 | 69.783 ± 0.048 d | 0.048 | 0.0 | 6 |
192Ir | 1 | 2.4 | 73.810 ± 0.019 d | 0.019 | 0.0 | § |
195Au | 5 | 0.6 - 6.0 | 186.098 ± 0.047 d | 0.021 | 0.042 | § |
198Au | 4 | 4.5 - 7.4 | 2.69517 ± 0.00021 d | 0.00021 | 0.0 | § |
201Tl | 12 | 2.6 - 11.5 | 3.0456 ± 0.0015 d | 0.0004 | 0.0014 | § |
202Tl | 1 | 1.4 | 12.466 ± 0.081 d | 0.081 | 0.0 | § |
203Hg | 14 | 1.7 - 6.6 | 46.619 ± 0.027 d | 0.007 | 0.026 | § |
203Pb | 7 | 1.8 - 2.8 | 51.923 ± 0.037 h | 0.013 | 0.034 | § |
207Bi | 2 | 0.9 | 11523. ± 15. d | 9 | 12 | §,6 |
228Th | 6 | 1.7 - 8.3 | 698.60 ± 0.36 d | 0.14 | 0.33 | § |
* |
The stated uncertainties are the sum,
in quadrature, of the statistical uncertainty (the "external standard deviation"
in the weighted mean) and other uncertainties which include those from the
Stevenson equation (NBS Special Publication 626) and from the correction for
the 210Bi ingrowth in the radium reference sources. |
(a) |
Measured by internal gas proportional counting. |
(b) |
Normal saline solution. |
(c) |
Acid solution. |
This work was supported in part by NIST's Systems
Integration for Manufacturing Applications (SIMA) Program.
NIST Standard Reference Database 120
Inquiries or comments: Feedback
Online: May 1997 Last Update: April 2003
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