Version History

Example of how to reference this online database: (Replace year, month day with database access date.)

Unterweger, M.P. (2003), Radionuclide Half-Life Measurements at the National Institute of Standards and Technology (version 3.0). [Online] Available: http://physics.nist.gov/Halflife [year, month day]. National Institute of Standards and Technology, Gaithersburg, MD.

Citation Form:

Author/editor (Year), Title (edition). [Type of medium] Available: URL [Access date].

Version 3.0 April 2003		Radionuclides ³²P, ^99mTc (acid), ¹⁰³Ru, and ¹⁸⁸W were added; and the values for ⁶⁰Co, ⁶²Cu, ⁸⁵Kr, ¹²⁵Sb, ¹³³Ba, ¹³⁷Cs, ¹⁴⁴Ce, ¹⁵²Eu, ¹⁵⁴Eu, ¹⁵⁵Eu, ¹⁶⁶Ho, ¹⁸⁸Re, and ²⁰⁷Bi and the associated references were changed.
Version 2.1 August 2000		The value of the half-life of ³H (tritium) was improved from 4504 ± 9 d to 4500 ± 8 d, and the associated reference was changed.
Version 2.0 July 1999		Radionuclides ³H, ⁴⁴Ti, ⁶²Cu, ^117mSn, and ¹⁷⁷Lu were added and the layout was redesigned.
Version 1.0 May 1997		Available online.
NBS SP 626 1982		D.D. Hoppes and F.J. Schima NBS Special Publication 626