Elastic Scattering of α‐Particles on Be⁹

Abstract

The differential cross-section for the elastic scattering of He4 particles on Be9 has been studied in the bombarding energy range 1.4-2.5 MeV.The excitation functions for the elastically smttered a-particles from BeQ were measured a t six angles 90". 125", 132", 140", 160" and 160" in the centre of mass system. A clear and pronounced resonance is observed in the measured cross-section a t incident a-particle energy 1.93 MeV. Analysis of the data in terms of the single level approximation 5' theory leads to the assignment J" =for the observed resonance. Reduced and partial 2 widths for elastic scattering were determined.

Spectroscopy of C13 above the α threshold with α+Be9

“…Since low energy states can interfere with higher energy states changing the shape of excitation functions [51], we complemented our elastic scattering DCS data-set with data at θ cm = 160,150 • taken from Ref. [33] and covering the energy range E α 1.0-1.7 MeV. During the R-matrix fit procedure, we allowed the presence of small normalization factors (within 15% from unity) to account for eventual absolute normalization errors in the original data set of Ref.…”

“…During the R-matrix fit procedure, we allowed the presence of small normalization factors (within 15% from unity) to account for eventual absolute normalization errors in the original data set of Ref. [33].…”

“…Despite the strong theoretical efforts, experimental data on the structure of 13 C at excitation energies above the α emission threshold are quite fragmentary and often characterized by conflicting J π assignments that prevent any firm conclusions on the structure of this nucleus. Possible reactions that can help to clarify the situation are the α + 9 Be elastic and inelastic resonant scattering [25,[31][32][33][34][35][36], 9 Be(α,n) 12 C reactions [37][38][39], n+ 12 C elastic and inelastic scattering [40][41][42] and transfer reactions, such as the 9 Be( 6 Li,d) 13 C * case [26,43,44]. A review of results concerning 13 C spectroscopy is reported in Ref.…”

The role of 13C excited states in α+9Be reaction and scattering cross sections

“…Our data set was complemented with low energy data of Ref. [30] and by including also neutron data from Ref. [25] and [26].…”

Analysis of excited states in 13C and their cluster structure

“…Because of the clustered structure of 9 Be, α+ 9 Be reactions have been proposed to be very powerful tools to explore the spectroscopy of 13 C above the α-threshold [13]. When an α-particle strikes a 9 Be, dominant reactions are the elastic or inelastic resonant scatterings, respectively 9 Be(α,α) and 9 Be(α,α ) [13][14][15][16][17][18][19], and the 9 Be(α,n) reactions [20,21]. To help to clarify the spectroscopy of 13 C above the α-threshold, we performed, for the first time, * e-mail: ivano.lombardo@ct.infn.it a completely unified and comprehensive analysis of the above mentioned reactions in terms of the R-matrix theory.…”