Abstract
The partial widths for α-particle and γ-ray decay of the second 2
+
T = 1 level in
20Ne at 12.22 MeV have been measured. The reaction
19F(
3He, d)
20Ne was employed, with deuterons detected in singles and in coincidence with γ-rays from the decay of the 12.22 MeV level. The coincidence efficiency was determined using the 100% γ-decay of the 10.89 MeV 3
+
T = 1 level. The ratio of the γ-decay width to the total width of the 12.22 MeV level was measured to be 0.88 ±0.05, which combined with a recent 16
O(α, γ)
20Ne measurement yields a very small α-particle width of 0.32±0.06 eV. This result is also of relevance to the radiative decay of the 18.43 MeV 2
+
T = 2 level in
20Ne, and confirms a large discrepancy between the measured γ-decay width of the 2
+
T = 2 level and the predictions of the shell model.