Scattering ofαParticles Research Articles

Scattering of α-particles by 11B nuclei at an energy of 40MeV and role of the exchange mechanism with transfer of 7Li

The elastic and inelastic scatterings of [Formula: see text]-particles were investigated at an energy of 40[Formula: see text]MeV with excitation of low-lying states of the [Formula: see text]B nucleus [0.0 (3/2[Formula: see text]), 4.445 (5/2[Formula: see text]), 6.74 (7/2[Formula: see text]), 2.125 (1/2[Formula: see text]) and 5.02[Formula: see text]MeV (3/2[Formula: see text])]. The analysis of the experimental angular distributions was carried out via the coupled channels method within the framework of the collective model. The value of the quadrupole deformation parameter [Formula: see text] was extracted. Calculations indicate a preference for a negative sign for deformation. It is shown that the exchange mechanism with the transfer of the heavy 7Li cluster does not play an important role in the scattering of [Formula: see text]-particles on [Formula: see text]B nuclei at an energy of 40[Formula: see text]MeV.

Scattering of α-particles and 3He on 16O nuclei and its excitation mechanism at energies near 50MeV

Elastic and inelastic scattering of [Formula: see text]-particles at 48.1[Formula: see text]MeV and 3He at 60[Formula: see text]MeV on [Formula: see text]O nuclei has been measured with excitation of states at 6.05 (0[Formula: see text])–6.13 (3[Formula: see text])[Formula: see text]MeV, 6.92 (2[Formula: see text])–7.12 (1[Formula: see text])[Formula: see text]MeV and 8.87 (2[Formula: see text])[Formula: see text]MeV. The center-of-mass beam momenta are the same for these two strongly absorbed particles. Analysis of angular distributions was performed in the frameworks of the optical model, the coupled channels method and the Distorted Wave Born Approximation (DWBA). A good description of experimental data was obtained over the full angular range without taking into account the spin-orbit interaction and the cluster transfer mechanism with real potentials that have volume integrals of about 400[Formula: see text]MeV fm3. Collective and microscopic models were used in the analysis of the inelastic scattering. The values of the octupole deformation lengths were extracted. It is shown that nuclear rainbow effects appear not only in the elastic, but also in the inelastic scattering with excitation of the 3[Formula: see text] state of [Formula: see text]O.

Scattering of α-particles at medium energies

Elastic scattering of α-particles is treated within the context of high energy multiple diffraction theory. Terms up to fourth order in the expansion of the optical phase-shift function are retained (when necessary). The theoretical predictions are compared with the recent 5.05 and 4.30 GeV/ c α-α measurements. The effects of short-range dynamical correlations are discussed.

Elastic Scattering ofαParticles byBe9and Highly Excited States ofC13

Elastic Scattering ofαParticles byBe9and Highly Excited States ofC13

Elastic scattering of α-particles by 12C and the structure of 16O

Abstract Scattering of α-particles by 12 C has been investigated by the coupled-channel method in the weak-coupling model of the α-particle and 12 C nucleus. For 12 C the rotational model is adopted and the α-particle is simply treated as a point particle. Spin and angular momentum dependent interactions have been taken into account as a correction to the α- 12 C potential. We calculated the energies and widths of the resonance levels, the energies of the two bound states, the phase shifts, the excitation functions and the angular distributions of the differential cross sections, up to E α = 8 MeV. The experimental data are reasonably well reproduced. The deformation parameter of the α- 12 C potential is considerably different from that of the nucleon- 12 C potential. The reason for this difference is discussed.

Atomic Physics and Related Subjects.: Communications to Nature.: Scattering of α-Particles by Light Atoms

IN a letter to NATURE of Feb. 1, and in greater detail in the Philosophical Magazine, vol. 9, No. 56, February 1930, Prof. A. C. Banerji has discussed some wave mechanical calculations on the scattering of α-particles by light atoms. I should like to make some remarks on this problem, which I have treated in a paper to appear in the Zeitschrift fur Physik.

Scattering of α-Particles by Light Atoms

IN a recent discussion at the Royal Society (NATURE, vol. 123, p. 246), Sir Ernest Rutherford pointed out the great importance of the experiments on the scattering of α-particles by light atoms like those of magnesium, aluminium, helium, and hydrogen which are being carried out at the Cavendish Laboratory by himself and his co-workers Bieler, Chadwick, and others. The results of these experiments show very wide variation from the classical expression obtained on the assumption of an inverse square law, and led Rutherford and Bieler to the view that the repulsive force between positively charged particles changes into an attractive one when the distance of approach is less than 3 × 10−13 cm. Many attempts have been made to get an exact expression for this force. Bieler thought the force to be given by the law F = Ze2/r − μ/r4, while Debye and Hardemeier took the additive term to be inversely proportional to the fifth power of the distance.

XCIX. Scattering of α-particles by atomic nuclei and the law of force

(1925). XCIX. Scattering of α-particles by atomic nuclei and the law of force. The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science: Vol. 50, No. 299, pp. 889-913.