Investigation of particle-unbound excited states in light nuclei with resonance-decay spectroscopy using aBe12beam

Abstract

Resonance-decay spectroscopy is used to study particle-unbound excited states produced in interactions of E/A = 50 MeV 12 Be on polyethylene and carbon targets. The particle-unbound states are produced in a variety of reaction mechanisms, ranging from projectile fragmentation to proton pickup. New proton-decaying excited states are observed in 9 Li(E * = 14.1 ± 0.1 MeV, = 207 ± 49 keV) and 10 Be(E * = 20.4 ± 0.1 MeV, = 182 ± 74 keV). In addition a new α-decaying state is observed in 13 B(E * = 13.6 ± 0.1 MeV, 320 keV). Also found was a 8 Be state with E * = 23 MeV, = 616 ± 30 keV, which decays to the p + 3 H + α channel. Correlation between the fragments indicates that the decay is initiated by a proton emission to the 4.63-MeV state of 7 Li and the spin of the state is J > 2. A second T = 2 state was confirmed in 12 B at 14.82 MeV, which decays to the p + 11 Be, 3 H + 9 Be, and α + 8 Li channels. Its width was found to be 100 keV and its spin is consistent with J π = 2 + .

Invariant-mass spectroscopy of Ne18, O16 , and CCharity1, Brown2, Elson3 et al. 2019Phys. Rev. CSelf Cite252420View full textAdd to dashboardCite

“…Note that we are using the excitation energy from Refs. [53][54][55] rather than the compiled value of E * =9.560 MeV [18]. The width of our 10 C peak (Γ=490 keV [3]) is of similar magnitude but larger than the value of Γ=141 keV [18] for the J=2 + level in the mirror system which is not unreasonable as the protonrich member of a mirror pair of levels in the continuum generally has a larger width.…”

“…This is the only available final exit channel for particle decay until E * =15.0 MeV when the 3 He+ 7 Be channel is available. A number of invariant-mass studies have investigated 2p+2α exit channels produced in the inelastic excitation of a 10 C beam [50][51][52][53]. Numerous states were observed whose decay are initiated by either by p, α, or direct two-proton emission.…”

Invariant-mass spectroscopy of $^{18}$Ne, $^{16}$O, and $^{10}$C excited states formed in neutron transfer reactions

“…Note that we are using the excitation energy from Refs. [50][51][52] rather than the compiled value of E * =9.560 MeV [18]. The width of our 10 C peak (Γ=490 keV [3]) is of similar magnitude but larger than the value of Γ=141 keV [18] for the J=2 + level in the mirror system which is not unreasonable as the protonrich member of a mirror pair of levels in the continuum generally has a larger width.…”

“…This is the only available final exit channel for particle decay until E * =15.0 MeV when the 3 He+ 7 Be channel is available. A number of invariant-mass studies have investigated 2p+2α exit channels produced in the inelastic excitation of the a 10 C beam [47][48][49][50]. Numerous states were observed whose decay are initiated by either by p, α, or direct two-proton emission.…”

Multi-Channel Integrated Circuits For Use In Research With Radioactive Ion Beams

“…These works include the study of 6 Be [3,4], 10 C [5, 6, 7], 12 Be and other light neutron-rich nuclei [8,9]. These works include the study of 6 Be [3,4], 10 C [5, 6, 7], 12 Be and other light neutron-rich nuclei [8,9].…”