1978MOZL: ²⁰Mg; measured σ(E_p) for β-delayed proton. ²⁰Mg deduced decay scheme.

1979AYZX: ²⁰Mg; measured spectra of β-delayed protons. ²⁰Mg deduced T_1/2, mass, coefficients of isobaric multiplet mass equation.

1979MO02: ²⁰Mg; measured β-delayed protons. ²⁰Na deduced mass excess.

1980MOZM: ²⁰Mg; measured β-delayed E_p, I_p. ²⁰Na deduced T = 2, 0⁺ state mass excess.

1981AY01: ²⁰Mg; measured β-delayed E_p, I_p; deduced T_1/2, proton-branching; deduced coefficients of isobaric multiplet mass equation. ²⁰Na level deduced mass excess.

1991KUZP: ²⁰Mg(β⁺); measured E_p, E_β, E_γ.

1991KUZR: ²⁰Mg(β⁺); measured E_p, E_β, E_γ; deduced rapid proton process mechanism. ²⁰Na deduced levels.

1992GO10: ²⁰Mg(β⁺p); measured β-delayed E_p, I_p; deduced log ft.

1992KU07: ²⁰Mg(β⁺); measured T_1/2, βp-coin; deduced log ft. 20Na deduced levels, possible J, π.

1992KU24: ²⁰Mg(β⁺); measured decay curve. ²⁰Na deduced 1⁺ state may not be s-wave resonance.

1992KUZO: ²⁰Mg(β⁺); measured E_p, E_α, T_1/2 of ²⁰Mg. ²⁰Na deduced levels, J, π.

1992KUZQ: ²⁰Mg(β⁺), (β⁺p); measured E_p, pβ-, αβ-coin, T_1/2. ²⁰Mg deduced β⁺ decay branching. ²⁰Na deduced levels, J, π, β⁺ decay branching.

1992PIZT: ²⁰Mg(β⁺p); measured β-delayed particle spectra, E_β, I_β, γγ-coin; deduced r-process implications. ²⁰Na deduced levels, Fermi, Gamow-Teller transition strengths.

1993PIZZ: ²⁰Mg(β⁺p); measured β-delayed particle-, γ-spectra; deduced log ft consequences on ¹⁹Ne(p, γ) reaction. ²⁰Na deduced levels, J, π, β-branching ratio.

1995PI03: ²⁰Mg(β⁺p); measured β-delayed E_p, I_p, γ spectra. ²⁰Na levels deduced J, π, β-decay feeding upper limit, Gamow-Teller transition strength.

2010SIZW: ²⁰Mg(β⁺p); measured β-delayed E_p, I_p.

2012WA15: ²⁰Mg(β⁺p); measured decay products, E_β, I_β, E_p, I_p. ¹⁹Ne; deduced proton energy spectrum, resonant states, resonance strengths.

2015GL03: ²⁰Mg(β⁺); measured E_γ, I_γ, βγ-coin. ²⁰Na; deduced levels, precise energy of the T = 2 state, J, π.

2016LI45: ²⁰Mg(β⁺p), (β⁺2p); measured decay products, E_p, I_p; deduced energy, T_1/2, branching-ratios.

2016LU13: ²⁰Mg(β⁺p); measured decay products, E_p, I_p, E_γ, I_γ; deduced T_1/2, decay scheme, J, π, absolute beta-delayed proton emission branching ratio, resonance parameters.

2017SU05: ²⁰Mg(β⁺), (β⁺p); measured reaction products, E_p, I_p, E_γ, I_γ, γγ-, γβ- and pβ-coin, (²⁰Mg)γ-coin, half-life of ²⁰Mg decay. ²⁰Na, ¹⁹Ne; deduced levels, branching ratios, log ft values.

2017WR02: ²⁰Mg(β⁺), (β⁺p); measured E_γ, I_γ, βγ- and (implants)γ-coin. ¹⁹Ne; deduced level at 4034 keV, β⁺-delayed proton branching ratio; discussed possible α-decay of 4034 level. ²⁰Mg(β⁺α); discussed possible decay branch.

2018GL01: ²⁰Mg(β⁺), measured decay products, E_β, I_β, E_γ, I_γ; deduced γ-ray energies and limits on intensities of β-delayed γ-rays, Gamow-Teller strengths B(GT) and associated log ft values.

2019GL02: ²⁰Mg(β⁺p), measured E_β⁺, E_γ, I_γ, β⁺γ-coin, γ-decay branching ratios, and E(p). ¹⁹Ne; deduced levels, J, π, half-life of 1507.5 level from Doppler broadening analysis, β⁺p feedings.

2020BA07: compiled β⁺-delayed proton (or α) emission for very neutron-deficient nuclei, J, π, T_1/2, branching ratios.

Measured half-life for ²⁰Mg(β⁺)²⁰Na

Recommended value (April, 2017):	90.4 ± 0.7 ms
Summary Table of Uncertainty Analysis:	(PDF);	Summary chart of all values:    (PDF)
Measured values:	90.0 ± 0.6 ms	(2017SU05)
	91.4 ± 1.0 ms	(2016LU13)
	95 ± 3 ms	(1995PI03)
	82 ± 4 ms	(1992GO10)
	114 ± 17 ms	(1992KU07)
	95+80-50 ms	(1979MO02, 1981Ay01)
	85 ± 15 ms	(1964FL03)
Other Reviews:	91 ± 4 ms	(Our analysis in August, 2015)

Previous Measurements

 

Decay to 20Na* (keV) a	Jπ a	Branching Ratio (%)			log ft			B(GT) b
		(1992GO10)	(1992KU07)	(1995PI03) c	(1992GO10)	(1992KU07)	(1995PI03)	(1995PI03)
984.25 ± 0.10	1+	74 ± 7	85	69.7 ± 1.2	3.70 ± 0.05	3.87	3.83 ± 0.02	0.579 ± 0.030
2645	?	≤ 0.2	< 1	≤ 0.1	≥ 5.85	> 5.42	≥ 6.24	≤ 0.002
3001 ± 2	1+	10.7 ± 0.5	9	11.5 ± 1.4	3.99 ± 0.04	4.31	4.08 ± 0.06	0.33 ± 0.05
3874 ± 15	1+	5.4 ± 0.5	5	4.8 ± 0.6	3.99 ± 0.05	4.26	4.17 ± 0.06	0.27 ± 0.04
4123 ± 16	1+			2.7 ± 0.3			4.33 ± 0.06	0.18 ± 0.03
≈ 4800 d	1+			≥ 1.9 [3.6 ± 0.5]			≤ 4.23 [3.95 ± 0.06]	≥ 0.23 [0.45 ± 0.07]
≈ 5600 d	1+			≥ 1.5 [2.8 ± 0.4]			≤ 3.97 [3.70 ± 0.06]	≥ 0.42 [0.79 ± 0.10]
6266 ± 30	1+			1.2 ± 0.1			3.72 ± 0.06	0.75 ± 0.11
6521 ± 30	0+	3.0 ± 0.8 e	1.5	3.3 ± 0.4	3.08 ± 0.22 e	3.68	3.13 ± 0.06	B(F) 4.57 ± 0.68
6770 ± 100	(1+)			≥ 0.03			≤ 5.01	≥ 0.04
6920 ± 100	(1+)			≥ 0.01			≤ 5.39	≥ 0.03
7440 ± 100	(1+)			≥ 0.01			≤ 4.99	≥ 0.04

a) From (1995PI03).

b) Gamow-Teller strength.

c) These branching ratios refer to the number of implanted 20Mg atoms as 100%. For details on branching of the proton decay into 19Ne levels see (1995PI03).

d) Unresolved levels. These are broad or unresolved states, for which the branching percentage could be determined only from proton emission to excited 19Ne levels. The numbers in square brackets indicate the estimated branch, log ft and B(GT) values under inclusion of the 3% branching to the 19Ne ground state.

e) Branching ratio for this super-allowed decay = (3 ± 2)%, and log ft = 3.18 in (1979MO02).

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²⁰N(β^-)²⁰O Evaluated Data

²⁰O(β^-)²⁰F Evaluated Data

²⁰F(β^-)²⁰Ne Evaluated Data

²⁰Na(β⁺)²⁰Ne Evaluated Data

A = 20 Beta-Decays Diagram

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Last modified: 24 June 2021