https://doi.org/10.1140/epja/i2005-10318-5
Regular Article - Nuclear Structure and Reactions
A study of pre-equilibrium emission of neutrons in 93Nb(α, xn) reactions
1
Department of Physics, Aligarh Muslim University, (UP)-202 002, Aligarh, India
2
Department of Physics, DSN College, (UP)-209 801, Unnao, India
Received:
20
June
2005
Accepted:
23
November
2006
Published online:
22
January
2007
With a view to study the pre-equilibrium emission mechanism in α-induced reactions the excitation functions for 93Nb(α, n)96m Tc, 93Nb(α, n)96Tc, 93Nb(α, 2n)95m Tc, 93Nb(α, 2n)95g Tc and 93Nb(α, 3n)94Tc reactions have been measured in the energy range threshold to ≈ 10MeV/nucleon using the activation technique. The measured excitation functions have also been compared with theoretical predictions based on the semi-classical code, which takes into account compound nucleus as well as pre-equilibrium emission. The analysis of the data indicates significant contribution from pre-equilibrium emission at these energies particularly in the high-energy tail portion of EFs. The effect of the variation of the parameters used in the code has been studied. The isomeric cross-section ratios have also been measured. It has been observed that the pre-equilibrium fraction increases rapidly with the increase in α-particle bombarding energy.
PACS: 25.55.-e 3H-, 3He-, and 4He-induced reactions – / 27.60.+j 90 ⩽ A ⩽ 149 –
© Società Italiana di Fisica and Springer-Verlag, 2007