Nuclear Physics Flashcards
Activity
Rate of decay per second
Background Radiation
Radiation that is found in small quantities all around us. It originates from natural sources such as rocks and cosmic rays as well as man-made sources such as nuclear accidents and medical sources.
Binding Energy
The amount of energy required to split a nucleus into all its separate constituent nucleons. It is equivalent to the mass defect.
Chain Reaction
The process of the neutrons released by a fission reaction inducing further fissile nuclei to undergo fission.
Closest Approach
A method of estimating a nuclear radius by firing a alpha particle at it. It involves calculating the distance at which all the alpha particle’s kinetic energy is converted to electric potential energy.
Contamination
The introduction of radioactive material to another object. The object is consequently radioactive.
Control Rods
Rods found in nuclear reactors to absorb neutrons and control the rate of reaction. They can be raised or lowered depending on the rate required.
Coolant
A substance that passes through nuclear reactors and is responsible for removing heat from the core. This heat is then used to generate energy.
Critical Mass
The smallest mass of fissile material required in a fission reactor for a chain reaction to be sustained.
Fission
The splitting a nucleus, to form two smaller daughter nuclei, neutrons and energy.
Fusion
The joining of two smaller nuclei to form a larger nucleus and to release energy.
Half-Life
The average time it takes for the number of radioactive nuclei in a sample to halve.
Inverse Square-Law
A law that governs the intensity of gamma radiation. It means that the intensity of radiation at any point is inversely proportional to the square of the distance from its source.
Irradiation
The exposure of an object to radiation. The exposed object does not become radioactive.
Mass Defect
The difference in mass between a nucleus and the sum of the masses of its constituent nucleons.
