Elastic Scattering of Deuterons by Heavy Nuclei

Abstract

In the present paper the elastic scattering of deuterons by heavy nuclei is investigated through the analysis of the available data at 11 MeV and 15.2 MeV. Because Ze~/fiv}>1 and the reduced wave-length of the deuteron is much shorter than the nuclear dimensions, the center-of-mass motion of the deuteron can be described by the classical approach. The wave mechanical description is applied only to the internal motion of the deuteron. It is shown that for the· deuteron scattering at 11 MeV the departure from the Rutherford scattering can be completely attributed to the electric breakup of the deuteron. The result of the analysis of the deuteron scattering at 15.2 MeV shows that although at larger scattering angles the effect . of the nuclear absol'ption due to the diffractional scattering of deuterons cannot be neglected, the main contribution to the departure from the Rutherford scattering comes from the effect of the electric breakup of the deuteron. The calculation of the cross section of the electric breakup by the semi-classical method of the virtual quanta modified for the non-relativistic case is performed to compare with the result obtained from the analysis. The limitation of this method is also discussed.In conclusion, it is emphasized that the mechanism of the elastic scattering of deuterons by heavy nuclei is quite different from those of the elastic scattering of alpha-particles by nuclei and of deuterons by light nuclei. § I. IntroductionWithin the past few years vartous experimental investigations were performed concerning the elastic scattering of alpha-particles 1 J and deuterons 2 J 3 J 4 J by nuclei. One of the most striking features of these data is the fact that the scattered intensity shows the departure from the Rutherford value beyond a certain angle at a fixed energy. Such a character in the elastic scattering of alpha-particles could be successfully explained for overall nuclei as a result of their interactions with the nuclear optical potential. 5 J 6 J However, the satisfactory interpretation of the deuteron scatterir g is so far unknown. It may be supposed that the cause of the departure in the deuteron scattering will not necessarily be similar to that of alpha-particles because of the marked difference of structures between them. However, some evidences 2 J of the elastic scattering of deuterons by light nuclei suggest that the departure from the Rutherford scattering is due to their nuclear interactions (e.g. the existence of the diffraction pattern in the angular distribution). Then a question arises about whether the departure in the deuteron scattering may be explained for overall nuclei by only nuclear interactions of deuterons. In order * The preliminary part of this work was published in Prog.

Accretion of Solid Materials Onto Circumplanetary Disks From Protoplanetary Disks

“…We can expect that, in the retrograde encounter regime, particles tend to get strong gas drag and are easy to be captured, while particles in the prograde encounter regimes are more difficult to be captured. Note that there are very narrow bands which show close encounter in a discontinuity manner with respect to b, which arises from multiple encounter in each orbit (e.g., Nishida 1983;Ida & Nakazawa 1989). But this is so narrow that the bands does not have any significant effect on the solid accretion rate onto the circumplanetary disk in a statistical sense.…”