A Study of 2H + 3He Elastic Scattering and the Reaction 2H( 3He, 4He)1H Between 17.5 and 44.1 MeV

摘要

An investigation of 2H + 3He elastic scattering and the reaction 2H ( 3He , 4He) 1H has been conducted at bombarding energies between 17.5 and 44.1 MeV to determine whether any states in 5Li, with appreciable widths for decay into two-body final states, exist in the region of excitation from 23.4 to 34 MeV in 5Li. An excitation function for 2H + 3He elastic scattering was measured at three laboratory scattering angles, and for 2H ( 3He, 4He) 1H at four laboratory scattering angles. No evidence was found for virtual states of the nucleus 5Li having appreciable two-body decay widths between 23.4 and 30.4 MeV excitation. Any such states have widths less than 200 keV between 23.4 and 25 MeV, less than 1.4 MeV between 25 and 30.4 MeV, less than 100 keV between 30.4 and 31 MeV, and less than 1 MeV between 31 and 34 MeV excitation in 5Li. Complete angular distributions for 2H + 3He elastic scattering and the reaction 2H( 3He , 3He) 1H were taken at several bombarding energies between 18.5 and 44.1 MeV. A partial-wave decomposition of the elastic scattering angular distributions has been performed. No anomalous behavior is observed. The angular distributions were also fitted with a linear Legendre polynomial series. Finally, the angular distributions have been compared to the predictions of two simple direct-reaction theories: the Butler stripping theory and the diffraction theory. The fits to the Butler theory are satisfactory, and the fits to the diffraction theory are remarkably good. Absolute differential cross sections were measured to an accuracy of 3%. At bombarding energies below 21.6 MeV they supplement existing data of comparable accuracy. Between 34.8 and 40.5 MeV bombarding energy, existing data are sparse, and of only moderate (14%) accuracy. The present work extends the data in this region, and improves the absolute accuracy by a factor of five. The differential cross sections measured above 40 MeV in the present, work are the only data in this energy region.