14C

¹⁴C

β^--Decay Evaluated Data

Measurements

1946RE10: ¹⁴C; measured T_1/2.
1948NO02: ¹⁴C; measured T_1/2.
1948YA02: ¹⁴C; measured T_1/2.
1949HA52: ¹⁴C; measured T_1/2.
1949JO07: ¹⁴C; measured T_1/2.
1950EN59: ¹⁴C; measured T_1/2.
1950MI10: ¹⁴C; measured T_1/2.
1951LI26: ¹⁴C.
1951MA30: ¹⁴C; measured T_1/2.
1954CA41: ¹⁴C.
1957LI51: ¹⁴C.
1961WA16: ¹⁴C; measured not abstracted; deduced nuclear properties.
1962OL04: ¹⁴C; measured not abstracted; deduced nuclear properties.
1964HU09: ¹⁴C; measured not abstracted; deduced nuclear properties.
1968BE47: ¹⁴C; measured not abstracted; deduced nuclear properties.
1968REZZ: ¹⁴C; measured T_1/2.
1971GO40: ¹⁴C; deduced log ft.
1972EM01: ¹⁴C; measured T_1/2.
1985RU09: ¹⁴C(β^-); measured I(β), I(ce).
1987GE04: ¹⁴C(β^-); measured maximum, average β^- energies.
1987MO19: ¹⁴C(β^-); measured β-spectra.
1987SM06: ¹⁴C(β^-); measured βγ-coin, β-count rate.
1988RA37: ¹⁴C(β^-); measured internal bremsstrahlung spectra following β-decay; deduced total internal bremsstrahlung yields.
1989BA33: ¹⁴C(β^-); measured β-spectra, I(ce).
1989TA08: ¹⁴C(β^-); measured β-activity.
1991NO07: ¹⁴C(β^-); measured β-spectra; deduced heavy neutrino evidence, mass, emission probability.
1993GR07: ¹⁴C(β^-); measured β-spectra unfolding, quench intensities.
1994GR04: ¹⁴C(β^-); measured β-counting rates, spectra.
1994HO11: ¹⁴C(β^-); measured integral β-counting rates.
1994SI21: ¹⁴C(β^-); measured activity. Triple-to-double coincidence ratio.
1994VA14: ¹⁴C(β^-); measured β-spectra.
1994YA05: ¹⁴C(β^-); measured E_β, I_β(θ); deduced anisotropy origin.
1995WI20: ¹⁴C(β^-); measured β-endpoint energy; deduced Q_β, no 17 keV neutrino evidence.
1996BE48: ¹⁴C(β^-); measured 2π-β counting rates; calculated 2π-β counting rates, E_β, I_β(θ).
1996SZ04: ¹⁴C(β^-); measured βγ-, (e)γ-, (X-ray)γ-coin.
1998AL07: ¹⁴C(β^-); measured β-spectra.
2000KU25: ¹⁴C(β^-); measured E_β, I_β.
2001CE02: ¹⁴C(β^-); measured β spectra.
2004KR10: ¹⁴C(β^-); measured E_β.
2005TO21: ¹⁴C(β^-); analyzed T_1/2.
2007CH90: ¹⁴C(β^-); analyzed available carbon dating data; measured decay products, E_β, I_β; deduced T_1/2 and its uncertainties, β spectrum.
2008AY04: ¹⁴C(β^-); compiled T_1/2 from various ISOL facilities.
2012AS03: ¹⁴C(β^-); analyzed data; deduced non-exponential nature of the decay from radiocarbon dating.
2016PO08: ¹⁴C(β^-); measured decay products; deduced exponential nature of nuclear decay.
2020SIZZ: ¹⁴C(β^-); measured decay products, E_β, I_β; deduced β-spectra.

Measured half-life for ¹⁴C(β^-)¹⁴N

Recommended value (September, 2015):	5686 ± 40 years:	Weighted average of all values below excluding (1952JE11).
		Note: Weighted average of the five most recent values is 5699 ± 20 years.
Summary Table of Uncertainty Analysis:	(PDF)
Measured values:	5736 ± 56 years	(1972EM01, 1968REZZ)
	5660 ± 30 years	(1968BE47)
	5745 ± 50 years	(1964HU09: Adjustment of 5760 ± 50 years from (1961MA32).
		Note: an estimated adjusted value of 5740 ± 50 years was used
		in determining 5730 ± 40 years in (1962GO33) below.)
	5680 ± 40 years	(1962OL04)
	5780 ± 65 years	(1961WA16)
	5900 ± 250 years	(1954CA41)
	5100 ± 85 years	(1952JE11) (Excluded)
	5370 ± 200 years	(1951MA30)
	5580⁺⁹⁰_-45 years	(1950EN59: 5580 ± 45 years is the published adjustment by -2.5% from 5720 ± 47 years in
		Engelkemeir, et al., Phys. Rev. 75 (1949) 1825. The value is often cited as 5580 ± 90 years.
		We take 5580⁺⁹⁰_-45 years.)
	6360 ± 190 years	(1950MI10)
	5513 ± 165 years	(1950MI10)
	6360 ± 200 years	(1949HA52)
	5589 ± 75 years	(1949JO07)
	5100 ± 200 years	(1948NO02)
	7200 ± 500 years	(1948YA02)
	4700 ± 400 years	(1946RE10)
Other Reviews:	5730 ± 40 years	(1962GO33: Value adopted at the 5th Radiocarbon Dating Conference, Cambridge, 1962.
		The value is the unweighted average of (1961WA16), (1962OL04) and 5740 ± 50 years from
		discussion in (1964HU09) (PDF). This value remains adopted in that community.)
	5568 ± 30 years	(1951AN1A: In the text the authors mention the value 5568 ± 30 years based on
		(Engelkemeir, et al., Phys. Rev. 75 (1949) 1825, 1949HA52, 1949JO07, 1950MI10, 1950EN59)
		(PDF). This value was widely used in the radiocarbon dating community. It is difficult to
		obtain this value using any combination of the pre 1951 values.)