Elastic and Inelastic Scattering of 28.5 MeV Alpha-Particles from O16, Ne20, Mg24 and Si28

Elastic and inelastic scattering of 28.5 MeV alpha-particles have been investigated. Blair's phase rule is fairly well satisfied in forward angles (<90°) with a few exceptions. Some anomalous diffractive patterns were obtained for 4 + states in O 16 , Ne 20 and Mg 24 , which have some common feature with each other. A relatively large yield from a doublet at 6.88 MeV in Si 28 seems to contradict the current assignment of spin-parity of the doublet. The inelastic scattering from unnatural-parity states in these nuclei shows a diffractive pattern and the relation between the phase and the angular momentum transfer is similar to the Blair's phase rule in spite of the reverse parity, except in the case of O 16 where the relation is almost reverse. The reaction mechanism is considered most probably to be a successive multiple excitation and/or an exchange process.

[1]  T. Tamura.  Adiabatic and non-adiabatic coupled channel calculations of the scattering of protons by deformed nuclei , 1964 .

[2]  J. L. Yntema,et al.  Shell-model selection rules and excitation of 4+ states in the Ti(α,α′) reaction , 1964 .

[3]  A. E. Litherland,et al.  An enhanced E3 transition in Ne20 , 1964 .

[4]  J. Kuehner,et al.  5.63 and 5.80 MeV levels of Ne20; de-excitation branching , 1964 .

[5]  P. Sorokin,et al.  Energy levels of the Si28 nucleus , 1964 .

[6]  E. B. Carter,et al.  ELASTIC SCATTERING OF ALPHA PARTICLES BY C$sup 12$ IN THE BOMBARDING ENERGY RANGE 10 to 19 Mev , 1964 .

[7]  W. B. Jones,et al.  Scattering of 65 MeV helium ions from O16 , 1964 .

[8]  H. Nakamura,et al.  Excitation of unnatural-parity states in (α, α′) scatterings on O16, Ne20, Mg24 and Si28 at 28.5 MeV , 1964 .

[9]  I. Kumabe,et al.  Elastic and Inelastic Scattering of 28.5 MeV Alpha Particles by Medium-Weight Nuclei , 1964 .

[10]  J. Faivre,et al.  Excitation des etats dits “a deux phonons” dans Fe56, Fe58, Ni62, Ni64 par diffusion inelastique de particules α de 44 MeV , 1963 .

[11]  J. K. Dickens,et al.  PROTON EXCITATION OF TWO-PHONON LEVELS , 1963 .

[12]  R. Nordhagen.  THE 936 AND 1261 kev RESONANCES IN THE $sup 27$Al(p,$gamma$)$sup 28$Si REACTION AND THE PROPERTIES OF THE 6.88 Mev DOUBLET STATE IN $sup 28$Si , 1963 .

[13]  R. Nordhagen,et al.  The 1315, 1362 and 1363 keV resonances in the 27Al(p, γ)28Si reaction and the properties of the 6.88 MeV doublet state in 28Si☆ , 1963 .

[14]  D. Brink,et al.  Excited states in oxygen 16 , 1963 .

[15]  E. Rost,et al.  Analysis of the Inelastic Scattering of Alpha Particles. I , 1962 .

[16]  J. Cramer,et al.  Production of Unnatural-Parity States by Inelastic Alpha-Particle Scattering , 1962 .

[17]  H. W. Broek.  A possible three-phonon group from Ni62 , 1962 .

[18]  R. Bent,et al.  Study of the Reaction Ne 20 (α, α'γ)Ne 20 , 1962 .

[19]  E. Rost,et al.  DISTORTED-WAVES THEORY OF DOUBLE-EXCITATION BY INELASTIC SCATTERING , 1962 .

[20]  E. Inopin.  INELASTIC DIFFRACTION SCATTERING , 1962 .

[21]  B. Buck.  EXCITATION OF TWO-PHONON STATES BY INELASTIC $alpha$-PARTICLE SCATTERING , 1962 .

[22]  T. H. Braid,et al.  ELASTIC AND INELASTIC SCATTERING OF 43-Mev ALPHA PARTICLES BY Ni$sup 58$ AND Ni$sup 6$$sup 0$ , 1962 .

[23]  J. Cookson,et al.  Decay schemes of excited states in Mg24 and Si28 and the collective model , 1962 .

[24]  P. Endt,et al.  Energy levels of light nuclei. III Z = 11 to Z = 20 , 1962 .

[25]  R. H. Lemmer,et al.  EXCITATIONS OF TWO-PHONON SURFACE VIBRATIONS IN NUCLEI , 1961 .

[26]  J. Kokame.  Inelastic Scattering of Protons from Several Light Odd-Even Nuclei in the Energy Range from 6.0 MeV to 7.5 MeV , 1961 .

[27]  A. B. Clegg.  Rotational bands in the 1p-shell , 1961 .

[28]  H. Gove,et al.  Rotational Bands inNe20 , 1961 .

[29]  J. P. Davidson,et al.  Octupole vibrations of deformed even nuclei , 1961 .

[30]  T. Mikumo.  ANOMALIES IN THE SCATTERING OF ALPHA PARTICLES BY CARBON , 1961 .

[31]  K. Wildermuth,et al.  Reduced widths in O16 and gamma transition probabilities in F19 , 1960 .

[32]  D. McDaniels,et al.  Alpha-particle excitation of quadrupole and octupole surface modes in Ti, Fe, Ni, Zn and Sr , 1960 .

[33]  D. McDaniels,et al.  Diffraction analysis of elastic and inelastic scattering by magnesium , 1960 .

[34]  H. Gove,et al.  Gamma rays from the 4.24 MeV state in magnesium-24 , 1960 .

[35]  W. Burcham,et al.  The scattering of 38 MeV α-particles by C, N, 0, F and Kr nuclei , 1960, Proceedings of the Royal Society of London. Series A, Mathematical and physical sciences.

[36]  R. E. Meads,et al.  γ-rays from 2+ States in 16O , 1960 .

[37]  J. Blair.  Inelastic Diffraction Scattering , 1959 .

[38]  G. W. Farwell,et al.  Angular distributions for elastic and inelastic scattering of 40-MeV alpha particles by carbon, nitrogen, oxygen, and argon , 1959 .

[39]  S. Kato,et al.  ELASTIC AND INELASTIC SCATTERING OF 22 Mev ALPHA PARTICLES BY LIGHT ELEMENTS , 1959 .

[40]  G. B. Shook.  ANGULAR DISTRIBUTIONS AND CORRELATIONS FOR ALPHA-PARTICLE SCATTERING BY C$sup 12$, Mg$sup 24$, AND Ca$sup 4$$sup 0$ , 1959 .

[41]  D. J. Tendam,et al.  Elastic and Inelastic Scattering of 18-Mev Alpha Particles from Neon, Argon, and Xenon , 1958 .

[42]  S. Yoshida.  Theory of Direct Interaction in Nucleon Inelastic Scattering , 1958 .

[43]  H. J. Watters.  ELASTIC AND INELASTIC SCATTERING OF 31.5-MEV ALPHA PARTICLES BY LIGHT NUCLEI , 1956 .