J C Willmott

The Energy Levels of 26Al

The 25Mg(p, γ)26Al reaction has been studied at six resonances in the region of 675 keV to 960 keV. New levels have been located at 2.32 MeV, 3.16 MeV, 3.76 MeV and 4.55 MeV, and the level at 2.09 MeV is shown to be a close doublet. Spins and parities have been assigned on the basis of angular distribution measurements. The resonances are shown to be reasonably pure isotopic spin states with the main transitions being E1 transitions satisfying the isotopic spin selection rules.

LXXXI. The angular distributions of α-particles from the 14N(d, α) reaction at low bombarding energies

Abstract The angular distribution of the α-particles from the 14N(d, α) reaction proceeding to the ground and first excited states of 12C have been studied at low bombarding energies. The results show that in the region of 21 mev excitation energy 16O has states 1-, 2+, 3-, but there is no state of zero spin and even parity.

The Energy Levels of 31P III: Comparison with the Nilsson Model

The spins and parities and decay properties of 31P determined in Parts I and II are compared with the predictions of the Nilsson model. It is found that the energies, spins and parities of the lower levels are well accounted for but not their decay properties.

The Energy Levels of 31P I: γ-ray Spectra and Decay Schemes

Gamma-ray spectra have been studied at ten resonances in the reaction 30Si(p, γ)31P and decay schemes found by analysis of the spectra and coincidence experiments.

On the 8·06 and 8·70 MeV states in ,4N

Abstract WE have recently reported measurements on the γ-rays emitted by the 1-, T=l state at 8–06 Mev in 14N (Broude et al. 1957). This level has a rather large isotopic spin impurity (∼7%) and a possible explanation of this has been given by Wilkinson and Clegg (1956) in terms of mutual contamination by the four states formed from a single 2s particle with the ground state of 13C as a unique parent. In a previous paper we suggested a possible identification of these four states on the basis of the weak decay modes of the 8.06 Mev state. The 8.70 Mev state in 14N is, like the 8.06 Mev state, a very broad level formed by s-wave capture of protons by 13C. It is a 0×, T = 1 state and possibly a member of this quartet of states. The present investigation had two purposes. Firstly to investigate the γ-ray decay scheme of the 8.70 Mev level and secondly to investigate the isotropy of the ground state transition from the 8.06 Mev state to see if the ingoing particle is purely s-wave. If there is a substantial d...

The Energy Levels of 31P II: Angular Distributions and Correlations

Angular distributions and triple correlations have been measured at the resonances in the reaction 30Si(p, γ)31P discussed in Part I and spin and parity assignments made for levels in 31P.

CXIII. The low lying levels of 25Al

Abstract The γ-ray spectrum at the 825 kev resonance in 24Mg has been investigated and the angular distributions of the three initial γ-rays measured. The spins and parities of the ground state and first excited states are confirmed as 5/2+ and 1/2+ respectively and the second excited state is shown to be 3/2+. Evidence is presented which lends a measure of support to the view that a level exists in 25Al at 1·92 mev.

Angular Distributions from (d, n) Reactions at 0.86 MeV Deuteron Energy

The angular distributions of neutron groups from the reactions 9Be(d,n)10B and 13C(d,n)14N have been measured for a deuteron energy of 0.86 MeV. The excitation energies of the first few excited states of 10B and 14N have been measured, and are in good agreement with previous measurements. The angular distributions have been analysed in terms of both compound nucleus and stripping interactions. Only the fourth excited state of 10B and the third excited state of 14N were found to be formed to a large extent by deuteron stripping.