ASNT Neutron Radiography

Question 1

What fundamental particle is used as the probing radiation in neutron radiography?

Accepted Answer

Neutron

Answer

Neutron radiography uses neutrons as the probing radiation to penetrate materials and reveal internal features.

Question 2

Which of the following is the primary advantage of neutron radiography over conventional X-ray radiography?

Accepted Answer

Ability to detect light elements like hydrogen in dense metal assemblies

Answer

Neutrons interact strongly with light elements such as hydrogen, making neutron radiography uniquely suited to imaging hydrogen-containing materials (explosives, organics, corrosion) inside heavy metals that X-rays cannot penetrate effectively.

Question 3

Which class of materials is most easily detected by thermal neutron radiography due to their high neutron attenuation cross-sections?

Accepted Answer

Light elements such as hydrogen, lithium, and boron

Answer

Thermal neutrons are strongly attenuated by light elements—particularly hydrogen, lithium, and boron—which have very large neutron capture or scattering cross-sections.

Question 4

What is the most common facility-based neutron source used for neutron radiography?

Accepted Answer

Nuclear research reactor

Answer

Nuclear research reactors are the most common source of high-flux thermal neutrons used for neutron radiography because they provide high neutron fluence rates.

Question 5

In the direct neutron radiography method, which converter screen material is most commonly paired with X-ray film?

Accepted Answer

Gadolinium foil

Answer

Gadolinium has an exceptionally high thermal neutron capture cross-section and emits low-energy electrons upon neutron absorption, which then expose the adjacent X-ray film.

ASNT - American Society for Nondestructive Testing, Inc. Practice Test

ASNT - American Society for Nondestructive Testing, Inc. Practice Test

ASNT Neutron Radiography