Investigation of the 47,49Ti(n, γ)48,50 reactions

Abstract

Ahstraet:The y-radiation produced by thermal neutron capture in enriched "'Ti and @Ti targets has been investigated.In the analysis 57 excited states of 48Ti and 31 of soTi have been identified. The Q-value of the 47Ti(n, y) reaction, 11 626.66(4) keV, is in agreement with previous data. The present value for 49Ti, 10 939.20(4) keV, differs by five standard deviations from a previous result.The nature of the neutron-capture mechanism has been investigated by comparing the present results with those from previous (d, p) work. It appears that in 47Ti capture proceeds through a doorway state and that the potential capture formalism is valid for 49Ti. Yet the @Ti cross section for transitions to p-states is predicted low by a factor of 4. The Fermi gas model gives a good representation of the nuclear level density in both nuclei. The combination of nuclear orientation measurements and circular polarization measurements has yielded the unambiguous determination of the spins of one 48Ti state and of five soTi states. Further spin and parity determinations for six 48Ti and for five "Ti states have been obtained from the analysis of the identified branches together with the results of previous experiments.Shell-model calculations, which yielded excitation energies, branching ratios, lifetimes and (d, p) spectroscopic factors, give a good representation of the experimental data for the low-lying states in both nuclei. NUCLEAR REACTIONS 47Ti(n, y), (polarized n, i), @Ti(n, y), (polarized n, +), E = E thermal; measured E,, I,(E,, 0), y-CP; deduced Q-values, 48Ti deduced levels, y-branching, J, rr, soTi deduced levels, y-branching, J, n. Enriched, polarized, unpolarized targets.

Decay spectroscopy of $^{50}$Sc and $^{50m}$Sc to $^{50}$Ti

“…There is good agreement between the current work and that from a previous β-decay study reported by Alburger et al [21] as well as with Ruyl et al [22] who utilized thermal neutron capture on metallic titanium targets. In the present work, the level scheme has been expanded with a number of levels and transitions observed for the first time in β decay.…”

“…The 3 + state also decays to the 1554 keV 2 + 1 state via a 2618 kev γ ray and is assigned an additional 1497 keV decay pathway to the 2675 keV 4 + 1 state. Both the 1497 and 2618 keV transitions are observed here with intensities that are in good agreement with neutron-capture measurements [22]. Both the measurement of γ-ray energies 2618.0(2), 1497.1(2) keV and intensities are consistent with dominant β-feeding to the 4171.968(17) keV 3 + state.…”

“…An estimate of the branching ratio for the unobserved 2 + 3 → 0 + 2 440 keV E2 transition is reported here via consideration of the 2314 keV transition (not observed in the present work) which is placed de-exciting the 0 + 2 state [22]. We assume that the intensity of the 2314 keV transition is directly analogous to the 440 since (i) no additional transitions are placed feeding the 0 + 2 state, (ii) the 0 + 2 → 2 + 1 decay has a branching ratio equal to unity and (iii) direct β feeding to the 0 + 2 state is unlikely.…”

β -decay Q values among the A=50 Ti-V-Cr isobaric triplet and atomic masses of Ti<

“…These results can be directly compared with the (n,γ) measurements of Ref. [43,44] that are used in the Ame2016 evaluation, see Table IV. This comparison provides a test of E = mc 2 , similar to that described in Ref.…”

“…Neutron separation energies obtained via cyclotron frequency ratio measurements described here, En, and from γ-ray spectroscopy measurements performed after neutron capture on47,48,49 Ti, Eγ[43,44].…”