Angular distributions of the reaction12C(d,p)13C belowE d=2 MeV

Abstract

Excitation functions of the 12C(d, Po) and 12C(d, d) reactions were measured at 90 ~ in the range E a = 900--2000 keV in 10 keV steps. Angular distributions of the 12C(d, p0)~aC reaction were measured in steps of 25 keV. The experimental data are interpreted in terms of interfering compound levels. Interference phenomena suggest additional new levels in ltN. l. IntroductionAngular distributions of the 12C(d,p0)13C reaction in the range Ea = =800--1500 keV were first measured by PHILLIrS [1] who also suggested spins and parities for the compound levels. SARMA et al.[2] determined angular distributions at 17 different bombarding energies in the same range. On assuming a pure compound nuclear reaction mechanism, these authors succeeded in assigning spins to four of the five known levels of 14N in the energy range concerned. The parity and spin assignments were made on the assumption that the neutron and proton reduced widths of the highly excited states in the N = Z nucleus 14N were of the same order of magnitude. Angular distributions of the (d, d), (d, p~) and (d, Pl) reactions were measured by KASHY et al. [3] up to 2 MeV. Spins, parities, as well as neutron, proton and deuteron reduced widths of five 14N levels were identified by least square fits of the theoretical angular distribution formula for many-level resonance reactions. In the same energy region, WILLIAMSON [4] studied the energy dependence of the distributions and observed, for the first time, significant Legendre components above L = 4. Two tentative spin assignments were made unambiguous by this very detailed experiment. The results of [1--4] ate summarized in Table I. However, every previous attempt had failed to reproduce the angular distributions above Ed = 1500 keV in terms of overlapping levels. Some of the authors [3] suspect the existence of several unidentified compound states in this region. --Resonances at Ea = 1730 keV and 1950 keV are known from 12C(d, n)~3N reaction [5, 6] but have not yet been observed in (d, p) processes.--As regards the non-resonant contribution, ir seems to play an important