Beta-delayed particle decay of 36K

Abstract

Protons and α-particles emitted from 36Ar levels following the β-decay of 36K ( T 1 2 = 0.34 s ) have been investigated. Delayed particles were detected using a surface barrier detector and a Microchannel plate in a back-to-back geometry. Five new proton groups and eight new α-particle groups at E p = 623, 1169, 1199, 1272, 1409 keV and E α = 1522, 1562, 1963, 2982, 3613, 3748, 3849, 4086 keV were identified. Particle branching ratios and corresponding upper limits for the log ƒt values of the precursor β + transitions were calculated. The observed particle groups were assigned to excited levels in 36Ar. Ratios of partial widths for proton and α-particle emission could be determined for two levels in 36Ar. New evidence for spin-parity assignments is presented. One of the new delayed α-particle groups corresponds to a previously unknown natural-parity state near the proton threshold in 36Ar. The implications for the explosive hydrogen burning of 35Cl are discussed.