A solid-state nuclear track detector or SSNTD (also known as an etched track detector or a dielectric track detector, DTD) is a section of a solid material (photographic emulsion

Emulsion

An emulsion is a mixture of two or more liquids that are normally immiscible . Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion is used when both the dispersed and the...

, crystal, glass or plastic) uncovered to nuclear radiation (neutron

Neutron

The neutron is a subatomic hadron particle which has the symbol or , no net electric charge and a mass slightly larger than that of a proton. With the exception of hydrogen, nuclei of atoms consist of protons and neutrons, which are therefore collectively referred to as nucleons. The number of...

s or charged particle

Charged particle

In physics, a charged particle is a particle with an electric charge. It may be either a subatomic particle or an ion. A collection of charged particles, or even a gas containing a proportion of charged particles, is called a plasma, which is called the fourth state of matter because its...

s, intermittently as well gamma ray

Gamma ray

Gamma radiation, also known as gamma rays or hyphenated as gamma-rays and denoted as γ, is electromagnetic radiation of high frequency . Gamma rays are usually naturally produced on Earth by decay of high energy states in atomic nuclei...

s), etched, and inspected microscopically. The pathway of nuclear particles are imprinted quicker than the body substance, in addition to the range and form of these trails acquiesce knowledge regarding the charge, mass, direction of motion of the particles as well as the energy. The benefits over other radiation detectors include the thorough knowledge accessible on distinctive particles, the perseverance of the passageways permitting measurements to be made over extended periods of time, and the easy, inexpensive and hearty construction of the detector.

The foundation of SSNTDs is that charged particles break the detector within nanometers down the path in such a way that the path can be imprinted persistently more rapidly than the unspoiled substance. Engraving, characteristically for some hours, extends the dent to tapering depths of micrometer dimensions, which can be seen with a microscope. For a known particle, the span of the pathway shows the energy of the particle. The charge can be acquired from the carve rate of the pathway in contrast to that of the main part. If the particles go through the exterior at normal incidence, the depths are circular; or else the ellipticity

Ellipse

In geometry, an ellipse is a plane curve that results from the intersection of a cone by a plane in a way that produces a closed curve. Circles are special cases of ellipses, obtained when the cutting plane is orthogonal to the cone's axis...

 and direction of the elliptical pit mouth suggests the direction of incidence.

SSNTDs are frequently used to learn more about cosmic ray

Cosmic ray

Cosmic rays are energetic charged subatomic particles, originating from outer space. They may produce secondary particles that penetrate the Earth's atmosphere and surface. The term ray is historical as cosmic rays were thought to be electromagnetic radiation...

s, long-standing radioactive elements, radon

Radon

Radon is a chemical element with symbol Rn and atomic number 86. It is a radioactive, colorless, odorless, tasteless noble gas, occurring naturally as the decay product of uranium or thorium. Its most stable isotope, 222Rn, has a half-life of 3.8 days...

 concentration in houses, and the age of geological samples.

A substance frequently used in SSNTDs is polyallyl diglycol carbonate (PADC), also known as Tastrak, CR-39 and CR39. It is a transparent, colorless, inflexible plastic with the chemical formula C₁₂H₁₈O₇. Etching to expose radiation damage is typically performed using solutions of caustic alkalis such as sodium hydroxide, regularly at high temperatures for a number of hours.

See also

• nuclear track detectors that are not solid state
  • cloud chamber
    Cloud chamber
    The cloud chamber, also known as the Wilson chamber, is a particle detector used for detecting ionizing radiation. In its most basic form, a cloud chamber is a sealed environment containing a supersaturated vapor of water or alcohol. When a charged particle interacts with the mixture, it ionizes it...
    
    
  • bubble chamber
    Bubble chamber
    A bubble chamber is a vessel filled with a superheated transparent liquid used to detect electrically charged particles moving through it. It was invented in 1952 by Donald A. Glaser, for which he was awarded the 1960 Nobel Prize in Physics...
    
    
• solid-state (semiconductor) nuclear detectors that do not record tracks
  • surface-barrier detector
  • silicon drift detector
    Silicon drift detector
    Silicon drift detectors are X-ray radiation detectors used in x-ray spectrometry and electron microscopy . Their chief characteristics compared with other X-ray detectors are:*high count rates*comparatively high energy resolution Silicon drift detectors (SDDs) are X-ray radiation detectors used...
    
    
  • lithium-drifted silicon detector - Si(Li)
  • intrinsic detector
• ion track

External links

• Gregory Choppin, Jan-Olov Liljenzin, Jan Rydberg Radiochemistry and Nuclear Chemistry, Chapter 8, "Detection and Measurement Techniques"