The dilution analysis is used to calculate the quantity of an unknown substance by addition of a radioactively marked substance with a well-known quantity and a well-known specific activity.

Leakage radiation is all radiation escaping from within the source assembly except for the useful beam. It is primarily controlled through the design of the tube housing and proper collimator filtering.

Neutron radiation is one type of ionizing radiation. Neutrons get emitted from an atom by the fission process or by decay processes. In the upper atmosphere neutron radiation is produced by the interaction of cosmic radiation with air. Neutron radiation is used for the production of medical isotopes and certain direct medical therapies.

See also Neutron Activation, Neutron Activation Analysis and Neutron Capture.

The primary radiation is the useful beam emitted from the x-ray source.

The calibration factor helps to convert between the measured value of a parameter and the actual value of that parameter in a system.
This normalization is necessary in cases where detectors and sensors do not directly sample a parameter, for example the radiation energy is measured by a detector that produces an electrical pulse whose total charge is proportional to the supplied radiation.