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Level Density of Light Nuclei

E. Gadioli and L. Zetta

  • Istituto di Fisica dell'Università di Milano, Italy and Istituto Mazionale di Fisica Nucleare, Sezione di Milano, Milano, Italy

Phys. Rev. 167, 1016 – Published 20 March, 1968

DOI: https://doi.org/10.1103/PhysRev.167.1016

Abstract

The level density of light nuclei (A70) is studied by analyzing statistical reaction spectra, slow-neutron resonances, and level widths at high excitation energy. Further evidence seems to indicate that, as proposed in a preceding work, the effective excitation energy of excited nuclei, appearing in the Lang-Le Couteur level-density formula, must be calculated by means of the following expression: U=(EΔ+70A) E is the usual excitation energy, Δ is the pairing energy, and 70A MeV is a term that shifts, in a smooth manner, the zero of the energy scale of different nuclei. In this case the Lang-Le Couteur formula, assuming R1.5A13 F, I=0.7Irig, a=(0.127A) MeV1, gives, without further changes of its parameters, a correct estimation of the slope and absolute value of the level densities of light nuclei for energies ranging from (1+Δ) up to ∼20 MeV. It is also shown that the preceding choice of the parameters of Lang-Le Couteur level-density expression allows one to reproduce very well the experimental distributions of low-energy levels observed with reactions which proceed, at least partially, through the formation of a compound nucleus.

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