Coulomb-nuclear interference in the inelastic scattering of deuterons by Ru99, Ru101

Author(s)

Cleber Lima Rodrigues

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Física (IF/SBI)
• Defense date: 2005-10-31

Examining board members

Thereza Borello Lewin; Nelson Carlin Filho; Mauro da Silva Dias; Diógenes Galetti; Otaviano Augusto Marcondes Helene

• Advisor: Thereza Borello Lewin

Abstract

Coulomb-Nuclear Interference measurements not previously reported in the 99,10 Ru odd nuclei complement the investigation of the collectivity of the first quadrupolar excitation in even Ru isotopes around A-I00, with projectiles that interact isoscarlarly with the nucleus. The Inelastic scattering angular distributions with 13 MeV incident deuterons on odd Ru stable nuclei were obtained in the facility Pelletron Accelerator - Enge Magnetic Spectrograph, using nuclear emulsion plates in the focal plane. Spectra associated with fourteen and sixteen scattering angles in 99Ru and 101Ru, respectively, were measured achieving an excellent characterization of the interference minimum of the core first quadrupolar excitation. The DWBADOMP description of the CNI with global optical model parameters employed allows the consistent analysis of the data in comparison with other analysis of the region. The simultaneous extraction of g N, mass deformation length and of C = C/N, ratio of charge (C ) and mass (N ) deformation lengths, was obtained in the fit of the theoretical predictions to the experimental angular distributions through the X2 minimization using the iterative Gauss-Marquardt method. Monte Carlo simulations of 5000 new sets of data, gaussian randomly generated, show the statistical adequacy of the method. The experimental values of C obtained distributed around 1.25 for 99Ru and 1.40 for lOlRu, with uncertainties of approximately 5%, indicating higher contribution of protons than neutrons in the excitations, in comparison with the N/Z ratios. The N measurements, with uncertainties less than 5%, point to lower values than published for even neighbor isotopes. The values of N and C extracted allow for the calculation of B(IS2), isoscalar reduced transition probability, and B(E2)/B(IS2), the ratio between electric (B(E2)) and isoscalar reduced transition probabilities. (AU)