Multi-step Direct Reaction Models
Including Collectivity in Nucleon Induced
Reactions
E. V. Chimanski, R. Capote, B. V. Carlson, and A. J. Koning
1 Introduction
Pre-equilibrium nuclear reaction is known as a particle emission process that takes
place after the first projectile–target interaction but long before the equilibrium
of the compound system is reached. Griffin in 1966, pioneered the description of
such events with the so-called Exciton Model [1]. Since then, many improvements
and extensions as well as new models were developed to describe pre-equilibrium
phenomena [2–6]. These models, although being very sophisticated, are limited by
their semi-classical nature, i.e., they do not take into account the interference effects,
which are quantum-based features. Quantum mechanical models were developed
during the late 1970s to the late of 1980s in the framework of a multi-step formalism
by Agassi [7], Tamura [8], Feshbach [9], and Nishioka [10, 11].
In the quantum mechanical approach, the pre-equilibrium space is divided into
two components: events involving continuum components belong to the P space
and are called Multi-Step Direct (MSD) reactions, while those dealing with boundstates Q are named Multi-Step Compound (MSC) reactions. The MSD describes a
highly energetic projectile (leading particle) that stays in the continuum and creates
new particle–hole pairs on its way through the target nucleus. This process usually
E. V. Chimanski ()
Aeronautics Institute of Technology, São José dos Campos, Brazil
NAPC-Nuclear Data Section, International Atomic Energy Agency, Vienna, Austria
e-mail: chimanski@ita.br
R. Capote · A. J. Koning
NAPC-Nuclear Data Section, International Atomic Energy Agency, Vienna, Austria
B. V. Carlson
Instituto Tecnológico da Aeronáutica, São José dos Campos, SP, Brazil
© This is a U.S. government work and not under copyright protection
in the U.S.; foreign copyright protection may apply 2021
J. Escher et al. (eds.), Compound-Nuclear Reactions, Springer Proceedings in
Physics 254, https://doi.org/10.1007/978-3-030-58082-7_8
65
Including Collectivity in Nucleon Induced
Reactions
E. V. Chimanski, R. Capote, B. V. Carlson, and A. J. Koning
1 Introduction
Pre-equilibrium nuclear reaction is known as a particle emission process that takes
place after the first projectile–target interaction but long before the equilibrium
of the compound system is reached. Griffin in 1966, pioneered the description of
such events with the so-called Exciton Model [1]. Since then, many improvements
and extensions as well as new models were developed to describe pre-equilibrium
phenomena [2–6]. These models, although being very sophisticated, are limited by
their semi-classical nature, i.e., they do not take into account the interference effects,
which are quantum-based features. Quantum mechanical models were developed
during the late 1970s to the late of 1980s in the framework of a multi-step formalism
by Agassi [7], Tamura [8], Feshbach [9], and Nishioka [10, 11].
In the quantum mechanical approach, the pre-equilibrium space is divided into
two components: events involving continuum components belong to the P space
and are called Multi-Step Direct (MSD) reactions, while those dealing with boundstates Q are named Multi-Step Compound (MSC) reactions. The MSD describes a
highly energetic projectile (leading particle) that stays in the continuum and creates
new particle–hole pairs on its way through the target nucleus. This process usually
E. V. Chimanski ()
Aeronautics Institute of Technology, São José dos Campos, Brazil
NAPC-Nuclear Data Section, International Atomic Energy Agency, Vienna, Austria
e-mail: chimanski@ita.br
R. Capote · A. J. Koning
NAPC-Nuclear Data Section, International Atomic Energy Agency, Vienna, Austria
B. V. Carlson
Instituto Tecnológico da Aeronáutica, São José dos Campos, SP, Brazil
© This is a U.S. government work and not under copyright protection
in the U.S.; foreign copyright protection may apply 2021
J. Escher et al. (eds.), Compound-Nuclear Reactions, Springer Proceedings in
Physics 254, https://doi.org/10.1007/978-3-030-58082-7_8
65