Nuclear Physics 3

How many nucleons from the target nucleus are involved in direct nuclear reactions?

• 3
• 2
• 1
• 4

What is the direction of product distribution in a direct nuclear reaction?

• The products are absorbed back into the target.
• The products are emitted in all directions equally.
• The products are emitted in the forward direction.
• The products are emitted only in the backward direction.

Which of these statements is NOT true about compound nucleus reactions?

• Resonances are formed

• The target nucleus absorbs energy and enters an excited state

• The interaction time is longer than in a direct nuclear reaction

• The energy of the incident particle is high

What is conserved in elastic scattering reactions?

• Only momentum is conserved.
• Momentum and kinetic energy are conserved.
• Only kinetic energy is conserved.
• Kinetic energy and potential energy are conserved.

Why can inelastic scattering be ignored in light nuclei?

• Inelastic scattering dominates in light nuclei because they have strong nuclear forces.
• Elastic scattering is negligible in light nuclei because of their large mass.
• Inelastic scattering is more significant in light nuclei due to their high binding energy.
• Inelastic scattering can be ignored in light nuclei because the energy level of their first excites state is too high.

Which of these represents a radiative capture reaction?

• A + n -> B + e (where e is an electron)
• A + n -> B + p (where p is a proton)
• A + n -> B + γ (where A is the target nucleus, n is the neutron, B is the new nucleus, and γ is the gamma ray)
• A + n -> B + 2n (where 2n are two neutrons)

What is the difference between radiative capture at small neutron flux and at high neutron flux?

• Small neutron flux results in fewer interactions and lower capture probabilities.

• There is no significant difference between small and high neutron flux.
• High neutron flux leads to lower interaction rates and fewer captures.
• Small neutron flux increases the likelihood of multiple captures.

Neutron capture reactions are responsible for:

• Pu breeding in reactor fuel.

• High burn up in reactor fuel.

• The formation of many fission products.

• Fission reactions.

Which of these equations is an example of a charged particle ejection?

• X + n → Y + α

• X + α → Y + n

• X + n → Y + γ

• X + n → Y + p

Which of these is an example of a primary source of neutrons?

• Spontaneous fission of Cf-252

• A Sb-Be neutron source

• (γ,n) production of photoneutrons

• An (α,n) neutron source