Absorbers consist of material that stops ionizing radiation. For example, lead, steel and concrete attenuate x-rays. Alpha particles and most beta particles can be stopped or absorbed by a sheet of paper or thin metal.
The absorption depends on the atomic number, density, thickness, etc. of the used material.
The interactions between the radiation and the absorber are three major processes: photoelectric absorption, Compton scattering, and pair production.

See also Absorption.

The x-ray absorption is the uptake of energy or the decrease of the number of photons by the tissue or matter through which the radiation travels.
Absorption in nuclear reactions and particulate radiation is a process of taking up kinetic energy of particles or the combination of particles with an atom, a nucleus, or another particle.
Absorption characteristics of imaged tissues are represented by their linear attenuation coefficients.

See also Absorber.

Chemical, usually acetic acid in the fixer and sodium carbonate in the developer, to neutralize the developer and to swell the gelatin, respectively.

See also Film Processor and X-Ray Film.

(ARS) The acute radiation syndrome is a form of radiation sickness. An acute radiation syndrome can be developed after the exposition to a high radiation dose received in a short period of time (e.g., x-rays or gamma rays). ARS subsyndromes include hematopoietic, cutaneous, gastrointestinal, and neurovascular diseases. The reaction will vary with dose and factors like age, medical co-morbitdity and immunosuppression.

Air KERMA (Kinetic Energy Released per unit MAss of air) measures the amount of radiation energy in air, unit is J/kg. This include the initial kinetic energy of the primary ionizing particles such as photoelectrons, Compton electrons, positron//negatron pairs from photon radiation, and scattered nuclei from fast neutrons, when for example air is irradiated by an x-ray beam. J/kg (gray) is also the unit of the radiation quantity 'Absorbed Dose'.