Kiyoji Fukunaga

Elastic Scattering of 14 MeV Protons by Deuterons and by Protons

The differential cross sections for the elastic scattering of 13.93 MeV protons by deuterons were measured with accuracy varying from 1 to 3% at angles from 12° to 164° in the center-of-mass system. A shallow Coulomb-nuclear interference minimum near 17° was observed. The angular distribution is in good agreement with that of neutrons scattered by deuterons at 14 MeV, although the p – d cross sections seem systematically a little smaller than the n – d cross sections at backward angles. For forward angles, the experimental results contradict with the prediction of the existing theory. The small-angle p – d elastic scattering at 10.14 MeV was also investigated and a similar shallow Coulomb-nuclear interference was observed, in contrast with the theoretical curve of Christian and Gammel. The p – p scattering experiment at 14.16 MeV is also described. Measurements were made with accuracy of 1 to 2% for angles from 30° to 114° in the center-of-mass system.

Elastic Scattering of Protons from B¹¹, Al, P, Co and Cu from 6 to 7.4 MeV

The energy dependence of the angular distributions of protons elastically scattered by the odd nuclei, B 11 , Al, P, Co and Cu, was measured in the energy range from 6 to 7.4 MeV by using the 105 cm Kyoto University Cyclotron. No remarkable energy dependence of the pattern of the angular distributions was found in all the energy and angular ranges studied. It may be concluded that a less energy dependence of the angular distributions of protons elastically scattered by the odd nuclei is due to a less contribution of the compound elastic scattering and moreover a less energy dependence of the compound elastic scattering.

Elastic and Inelastic Scattering of 14.7 MeV Deuterons and of 29.4 MeV Alpha-Particles by Li 6 and Li 7

The angular distributions of alpha-particles and deuterons scattered elastically and inelastically by Li 6 and Li 7 were measured. The 2.18 MeV state of Li 6 , the 0.478 MeV and the 4.63 MeV states of Li 7 were appreciably excited. The experimental angular distributions were analysed with the DWBA theory, and the deformation parameters of the above mentioned states were determined. Experimental results and the DWBA analysis show the existence of some difference between the inelastic scattering of alpha-particles by Li 6 and by Li 7 , while no appreciable difference was observed in the case of the deuteron scattering. The DWBA calculation predicts larger quadrupole deformations of the excited states of Li 6 and Li 7 as compared with rotational model calculations of the energy levels.

Continuous Energy Spectra of Protons and Alpha Particles Emitted by the Deuteron and Alpha Particle Reaction

Continuous energy spectra of protons and alpha particles have been studied in the deuteron-alpha particle scattering at the incident deuteron energy of 14.2 MeV. In the energy spectra of protons, the evidence for a final state resonance in the neutron and alpha particle system have been obtained and the energy spectrum is compared with the theory of final state interaction. There is a good agreement between the experiment and the theory. The angular dependence of the cross sections at peaks shows a stripping-like feature. The energy spectrum of the alpha particles at the higher energy is mainly affected by the effect of the final state interaction of the triplet S state in the neutron and proton system. The angular dependence of these alpha particles shows a forward peak in the laboratory system and it may be explained by an exchange process.

MEASUREMENT OF SPIN CORRELATION COEFFICIENTS IN p-p SCATTERING AT 52 Mev.

ABS>The methods and results of spin correlation coefficient C/sub nn/ measurements for p-p interections at 52 Mev at 90 deg in the C.M. system are discussed. (R.E.U.)

Multiple Scattering Correction on Quasi-Free Scattering

A rescattering effect in the multiple scattering is calculated for the transition amplitude of quasi-free scattering in the reaction p + d → p + p + n . The calculated results reproduce, except for a limited region, the ratio of the experimental cross section to the calculation on a spectator model in an impulse approximation. We find that the effect of the second scattering term and the spin factor are important in the difference between the p - p and p - n quasi-free scatterings.

MEASUREMENTS OF THE POLARIZATION IN PROTON-HELIUM ELASTIC SCATTERING

The polarization of protons elastically scattered by helium was measured by the double scattering method. Incident proton or alpha-particle beam was obtained from the INSJ 160-cm variable energy cyclotron. Three interdependent measurements, in which the polarization product was equul to P/sub 1/P/sub 2/, P/ sub 2/P/sub 3/, or P/sub 3/P/sub 1/, were made. The following results were obtained: P/sub 1/(6.2 Mev, 130.0 deg ) = 0.92 plus or minus 0.11: P/sub 2/(11.5 Mev, 61.1 deg ) =--0.45 plus or minus 0.06; and P/sub 3/(9.1 Mev, 61.1 deg ) = - -0.45 plus or minus 0.06, where angles and energies are those in the center-of- mass system. Experimental values of the polarization agreed well to the values calculated by using phase shifts, which were obtained from the analysis of the angular distribution of the scattering cross sections. (auth)

Breakup Reaction of 3He by 3He at 120 MeV

Kinematically complete experiments for the 3 He(τ, τ p ) d , d * reaction and the 3 He(τ, τ d ) p reaction were performed at 120 MeV. In the coincident energy spectra, large peaks corresponding to the quasi-free scattering were observed and bumps were also observed at higher part in the 3 He energy. The energy spectra were compared with the curves calculated on the basis of the Alt, Grassberger and Sandhas (AGS) formalism and the bump was reproduced well with the curve for the τ- d quasi-free scattering followed by the p - d final state interaction. Any evidence for the excited state of 3 He nucleus was not found.

Continuous Energy Spectra of Alpha-Particles from 11B(p, α)8Be Reaction

Spectra of alpha-particles emitted from the 11 B( p , α) 8 Be are obtained at the angle of 90° in the energy range from 6.5 to 7.3 MeV and also in the angular range from 20° to 160° at the proton energy of 7.26 MeV. The energy spectra are analyzed by a resonance formula. The width corresponding to the first excited state of 8 Be varies with the incident proton energy and the observing angle. The observed width is narrow at the resonance of the intermediate system of 12 C.

Inelastic Scattering of Alpha Particles by Be 9 at 28.5 MeV

Differential cross sections of the elastic scattering and the inelastic scatterings of alpha particles from Be 9 at the incident energy of 28.5 MeV are obtained. The angular distributions for the ground state and 2.43 MeV state show the clear diffractive nature. For the positive parity state, the phase relation of the experiment does not agree with the diffraction theory, and the interaction radius is smaller than those for the ground state and the collective state. The peak at 1.7 MeV in pulse height spectrum is considered to be caused by a final state interaction between the S wave neutron and the Be 8 nucleus.