Abstract: Fissionable materials are distinguished from other high-effective atomic number materials by producing dual-energy x-ray radiation sufficient to cause fission in fissionable materials and directing the dual-energy x-ray radiation sufficient to cause fission in fissionable materials towards a physical region. X-ray radiation and a product of fission from the physical region are sensed. An absorption of the dual-energy x-ray radiation by the physical region is determined based on the sensed x-ray radiation, and whether the physical region includes fissionable material is determined based on the presence of a product of fission.

Abstract: A first pulsed beam of charged particles from a particle accelerator is accelerated toward a first target that is configured to emit a fast neutron beam in response to being struck by an accelerated particle such that the fast neutron beam is directed toward a physical region. The last neutron beam includes a neutron having an energy sufficient to cause fission in a fissionable material. Data from a sensor configured to detect radiation of a fission product is accessed, and before accelerating a second pulsed beam of charged particles, whether the physical region includes a fissionable material based on the data from the sensor is determined.

Abstract: X-ray radiation is generated at a target that emits x-ray radiation in response to being struck by accelerated electrons, the electrons being emitted by a cathode that emits electrons in response to being illuminated by electromagnetic radiation from a source, and the x-ray radiation is moved by orienting a surface that directs the electromagnetic radiation from the source toward the cathode.