These types of reactions are called the compound nucleus reactions. There is always some non-direct (multiple internuclear interactions) component in all reactions, but the direct reactions have this component limited. What is the Compound Nucleus and the Nuclear Resonance?

In contrast, compound nucleus reaction involve many nucleon-nucleon interactions, in fact very many so these collisions lead to a complete thermal equilibrium (equal energy partition between nucleons) inside

The compound nuclei of certain energies are referred to as nuclear resonances. The formation of resonances is caused by the quantum nature of nuclear forces.

In nuclear physics and nuclear chemistry, a nuclear reaction is a process in which two nuclei, or a nucleus and an external subatomic particle, collide to produce one or more new nuclides. Thus, a nuclear reaction must cause a transformation of at least one nuclide to another.

Compound-nucleus model, description of atomic nuclei proposed (1936) by the Danish physicist Niels Bohr to explain nuclear reactions as a two-stage process comprising the formation of a relatively long-lived intermediate nucleus and its subsequent decay.

Compound Nucleus Reactions. The compound nucleus is a relatively long-lived intermediate state of particle-target composite system. The compound nucleus reactions involve many nucleon-nucleon interactions. The large number of collisions between the nucleons leads to a thermal equilibrium inside the compound nucleus.

Compound reactions involve much longer scales, as the energy of the captured projectile has to be distributed over all nucleons in the target. The reaction duration depends on the energy of the projectile. Typical time scales for the decay of a compound nucleus can vary between 10-16-10-15 s (at low beam energies) and 10-21-10-20 s (at high ...

17.1 Types of Reactions and Conservation Laws A typical nuclear reaction is depicted in Figure 17.1. The following two ways of describing that reaction are equivalent: a+X → Y+b , or X(a,b)Y . From now on, we shall usually use the latter because it is more compact (and easier to type!).

Theoretical and experimental physicists at LLNL collaborate to develop new approaches for studying nuclear reactions key to stockpile stewardship and the production of elements in the cosmos. Neutron-induced reactions touch every aspect of modern life.

Formation and decay of the compound nucleus are independent processes. Bohr’s compound-nucleus idea formalized in the Hauser-Feshbach formula for the average reaction cross section. Energy average (brackets) over many resonances.