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GENERAL: See Table 20.35 [Table of Energy Levels] (in PDF or PS).

Mass of ²⁰Na: From the threshold energy of the ²⁰Ne(p, n)²⁰Na reaction, E_thresh. = 15.419 ± 0.006 MeV, the atomic mass excess of ²⁰Na is 6.850 ± 0.006 MeV (GO71F, WI71F). See also (GA64A, GA66C, KE66C, HA69H).

1. 20Na(β+)20Ne

Qm = 13.892

²⁰Na decays by positron emission to ²⁰Ne*(1.63) and to a number of excited states which decay by α-emission to the ground state of ¹⁶O: see Table 20.34 (in PDF or PS) (PO67L, SU67C). The half-life of ²⁰Na is τ_1/2 = 408 ± 6 msec (SU67C), 448 ± 4 msec (OA70), 442 ± 5 msec (GO71F, WI71F), 446 ± 8 msec (MO72A). See also (59AJ76) and reaction 43 in ²⁰Ne.

The character of the β⁺ decay, which takes place by allowed transitions to 2⁺ states of ²⁰Ne, sets J^π = 2⁺ for the ground state of ²⁰Na.

2. 20Ne(p, n)20Na	Qm = -14.674
	Q0 = -14.674 ± 0.006 (GO71F).

Observed neutron groups at E_p = 22.9 MeV are displayed in Table 20.36 (in PDF or PS) (MO72). See also (OA70, BE71Y, RU71D, WI71F).

3. 20Ne(3He, t)20Na	Qm = -13.910
	Q0 = -14.04 ± 0.08 (PE65);
	Q0 = -13.89 ± 0.06 (DO65).

At E(³He) = 32 MeV, triton groups are observed to nine states of ²⁰Na: see Table 20.36 (in PDF or PS) (DO65, PE65).

4. 24Mg(p, αn)20Na

Qm = -23.989

See (PO67L, SU67C).