Moderator and beam port assembly for neutron radiography

Patent · Tue Jul 08 04:00:00 EDT 1986

OSTI ID:5455241

Whittermore, W L

A moderator and beam port assembly is described for use with a source of fast neutrons to provide a beam of thermal neutrons directed generally along an axis toward an object position for neutron radiography. The apparatus includes: a moderator formed of solid hydrogenous material, the moderator having a source cavity lying on the axis, means for supporting the source of fast neutrons adjacent the axis, the material having a high hydrogen density and substantially no neutron poisons and substantially surrounding the source cavity for thermalizing fast neutrons from the source within the moderator without substantial capture of the resulting thermal neutrons, aperture means containing neutron poisons outside the moderator for capturing substantially all neutrons striking the aperture means having energies less than a predetermined epithermal energy and for forming and defining an aperture disposed about the axis outside the moderator, the moderator having an axial inner beam port cavity therein extending about the axis axially from the aperture substantially to the source cavity for permitting thermal neutrons to escape from the moderator through the aperture.

• Assignee: GA Technologies, Inc., San Diego, CA
• Patent Number(s): US 4599515
• OSTI ID: 5455241
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420500* -- Engineering-- Materials Testing
APERTURES
ATTENUATION
BARYON REACTIONS
BARYONS
BEAMS
CAPTURE
COLLIMATORS
DENSITY
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
ELEMENTS
FAST NEUTRONS
FERMIONS
GAMMA RADIATION
HADRON REACTIONS
HADRONS
HYDROGEN
INDUSTRIAL RADIOGRAPHY
IONIZING RADIATIONS
METALS
MODERATORS
NEUTRON BEAMS
NEUTRON RADIOGRAPHY
NEUTRON REACTIONS
NEUTRON REFLECTORS
NEUTRONS
NONMETALS
NUCLEAR REACTIONS
NUCLEON BEAMS
NUCLEON REACTIONS
NUCLEONS
OPENINGS
PARTICLE BEAMS
PHYSICAL PROPERTIES
RADIATIONS
SHIELDING
SLOWING-DOWN
SPACE DEPENDENCE
THERMAL NEUTRONS
THERMALIZATION