Radionuclide Half-Life Measurements Made at NIST

Radionuclide Half Life Measurements Made at NIST

  Radionuclide     Number of
Sources Number of
  Half Lives
Followed   Half Life^*   Statistical
Standard
  Uncertainty   Other
Standard
  Uncertainty     Reference^¤

¹⁵²Eu 4 1.6 - 1.8 4947.2 ą 1.1 d 0.7 0.8 §,6

¹⁵⁴Eu 3 2.4 3145.2 ą 1.1 d 1.1 0.0 §,6

¹⁵⁵Eu 2 3.1 - 4.3 1739.06 ą 0.45 d 0.45 0.0 §,6

Radionuclide	Number of Sources	Number of Half Lives Followed	Half Life^*	Statistical Standard Uncertainty	Other Standard Uncertainty	Reference^¤
¹⁵²Eu	4	1.6 - 1.8	4947.2 ą 1.1 d	0.7	0.8	§,6
¹⁵⁴Eu	3	2.4	3145.2 ą 1.1 d	1.1	0.0	§,6
¹⁵⁵Eu	2	3.1 - 4.3	1739.06 ą 0.45 d	0.45	0.0	§,6

*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.

^¤The reference for every radionuclide is § unless otherwise noted.