Communication
Install
Faster access than browser!

# Mass attenuation coefficient

The mass attenuation coefficient, mass extinction coefficient, or mass narrow beam attenuation coefficient of the volume of a material characterizes how easily it can be penetrated by a beam of light, sound, particles, or other energy or matter. [1]

In physics, absorption of electromagnetic radiation is the way in which the energy of a photon is taken up by matter, typically the electrons of an atom.

## Absorption cross section

Absorption cross section is a measure for the probability of an absorption process.

## Attenuation

In physics, attenuation or, in some contexts, extinction is the gradual loss of flux intensity through a medium.

## Attenuation coefficient

Attenuation coefficient or narrow beam attenuation coefficient of the volume of a material characterizes how easily it can be penetrated by a beam of light, sound, particles, or other energy or matter.

## Attenuation length

In physics, the attenuation length or absorption length is the distance \lambda into a material when the probability has dropped to 1/e that a particle has not been absorbed.

## Beer–Lambert law

The Beer–Lambert law, also known as Beer's law, the Lambert–Beer law, or the Beer–Lambert–Bouguer law relates the attenuation of light to the properties of the material through which the light is travelling.

## Bremsstrahlung

Bremsstrahlung, from bremsen "to brake" and Strahlung "radiation"; i.e., "braking radiation" or "deceleration radiation", is electromagnetic radiation produced by the deceleration of a charged particle when deflected by another charged particle, typically an electron by an atomic nucleus.

## Cargo scanning

Cargo scanning or non-intrusive inspection (NII) refers to non-destructive methods of inspecting and identifying goods in transportation systems.

## Chemical species

A chemical species is a chemical substance or ensemble composed of chemically identical molecular entities that can explore the same set of molecular energy levels on a characteristic or delineated time scale.

## Collimated light

Collimated light is light whose rays are parallel, and therefore will spread minimally as it propagates.

## Compton edge

In spectrophotometry, the Compton edge is a feature of the spectrograph that results from the Compton scattering in the scintillator or detector.

## Compton scattering

Compton scattering, discovered by Arthur Holly Compton, is the scattering of a photon by a charged particle, usually an electron.

## Cross section (physics)

When two particles interact, their mutual cross section is the area transverse to their relative motion within which they must meet in order to scatter from each other.

## Crystallography

Crystallography is the experimental science of determining the arrangement of atoms in crystalline solids (see crystal structure).

## Density

The density, or more precisely, the volumetric mass density, of a substance is its mass per unit volume.

## Diffraction

--> Diffraction refers to various phenomena that occur when a wave encounters an obstacle or a slit.

## Dosimetry

Radiation dosimetry in the fields of health physics and radiation protection is the measurement, calculation and assessment of the ionizing radiation dose absorbed by the human body.

In physics, electromagnetic radiation (EM radiation or EMR) refers to the waves (or their quanta, photons) of the electromagnetic field, propagating (radiating) through space-time, carrying electromagnetic radiant energy.

## Energy

In physics, energy is the quantitative property that must be transferred to an object in order to perform work on, or to heat, the object.

## Gamma ray

A gamma ray or gamma radiation (symbol γ or \gamma), is penetrating electromagnetic radiation arising from the radioactive decay of atomic nuclei.

## High-energy X-rays

High-energy X-rays or HEX-rays are very hard X-rays, with typical energies of 80–1000 keV (1 MeV), about one order of magnitude higher than conventional X-rays (and well into gamma-ray energies over 120 keV).

## Interferometry

Interferometry is a family of techniques in which waves, usually electromagnetic waves, are superimposed causing the phenomenon of interference in order to extract information.

## International System of Units

The International System of Units (SI, abbreviated from the French Système international (d'unités)) is the modern form of the metric system, and is the most widely used system of measurement.

## Kilogram

The kilogram or kilogramme (symbol: kg) is the base unit of mass in the International System of Units (SI), and is defined as being equal to the mass of the International Prototype of the Kilogram (IPK, also known as "Le Grand K" or "Big K"), a cylinder of platinum-iridium alloy stored by the International Bureau of Weights and Measures at Saint-Cloud, France.

## Light

Light is electromagnetic radiation within a certain portion of the electromagnetic spectrum.

## Matter

In the classical physics observed in everyday life, matter is any substance that has mass and takes up space by having volume.

## Mean free path

In physics, the mean free path is the average distance traveled by a moving particle (such as an atom, a molecule, a photon) between successive impacts (collisions), which modify its direction or energy or other particle properties.

## Molar attenuation coefficient

The molar attenuation coefficient is a measurement of how strongly a chemical species attenuates light at a given wavelength.

## Molar mass

In chemistry, the molar mass M is a physical property defined as the mass of a given substance (chemical element or chemical compound) divided by the amount of substance.

## National Institute of Standards and Technology

The National Institute of Standards and Technology (NIST) is one of the oldest physical science laboratories in the United States.

## Pair production

Pair production is the creation of an elementary particle and its antiparticle from a neutral boson.

## Particle

In the physical sciences, a particle (or corpuscule in older texts) is a small localized object to which can be ascribed several physical or chemical properties such as volume, density or mass.

## Photoelectric effect

The photoelectric effect is the emission of electrons or other free carriers when light shines on a material.

## Photon

The photon is a type of elementary particle, the quantum of the electromagnetic field including electromagnetic radiation such as light, and the force carrier for the electromagnetic force (even when static via virtual particles).

## Propagation constant

The propagation constant of a sinusoidal electromagnetic wave is a measure of the change undergone by the amplitude and phase of the wave as it propagates in a given direction.

In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium.

In physics, the radiation length is a characteristic of a material, related to the energy loss of high energy, electromagnetic-interacting particles with it.

Radiography is an imaging technique using X-rays to view the internal form of an object.

## Ray (optics)

In optics a ray is an idealized model of light, obtained by choosing a line that is perpendicular to the wavefronts of the actual light, and that points in the direction of energy flow.

## Rayleigh scattering

Rayleigh scattering (pronounced), named after the British physicist Lord Rayleigh (John William Strutt), is the (dominantly) elastic scattering of light or other electromagnetic radiation by particles much smaller than the wavelength of the radiation.

## Scattering

Scattering is a general physical process where some forms of radiation, such as light, sound, or moving particles, are forced to deviate from a straight trajectory by one or more paths due to localized non-uniformities in the medium through which they pass.

## Scattering theory

In mathematics and physics, scattering theory is a framework for studying and understanding the scattering of waves and particles.

## Solution

In chemistry, a solution is a special type of homogeneous mixture composed of two or more substances.

## Solvent

A solvent (from the Latin solvō, "loosen, untie, solve") is a substance that dissolves a solute (a chemically distinct liquid, solid or gas), resulting in a solution.

## Sound

In physics, sound is a vibration that typically propagates as an audible wave of pressure, through a transmission medium such as a gas, liquid or solid.

## System of equations

In mathematics, a set of simultaneous equations, also known as a system of equations or an equation system, is a finite set of equations for which common solutions are sought.

## Transmittance

Transmittance of the surface of a material is its effectiveness in transmitting radiant energy.