Positively-charged, elementary, subatomic particles, constituents of all element nuclei having mass comparable to but slightly less than that of a neutron, and about 1836 times greater than that of an electron. They pass through matter with no detectable primary ionization. They interact with matter primarily through collision with other nuclei.
Neutrons are an essential tool in science.
Discovered in 1932 scientists have made increasing use of slow neutrons for studying the structure and dynamics of matter on atomic, molecular, and macro-molecular scales. The Spallation Process Spallation is thought to take place in two stages. Tantalum, tungsten, and lead are three examples of subactinide materials that can undergo high-energy fission following the cascade phase. Maximization of this leakage is another crucial aspect of spallation target design. The target designer also wants to control the leakage from the front surface of the target to minimize the neutrons that would otherwise head back down the high-energy beamline and be lost.