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In experimental and applied particle physics, a particle detector, also known as a radiation detector, is a device used to detect, track, and/or identify high-energy particles, such as produced by nuclear decay, cosmic radiation, or reactions in a particle accelerator. Modern detectors are also used as calorimeters to measure energy of the detected radiation. They may also be used to measure other attributes such as momentum, spin, charge etc. of the particles.

Description

Detectors designed for modern accelerators are huge, both in size and in cost. The term "counter" is often used instead of detector, when the detector counts the particles but does not resolve its energy or ionization. Particle detectors usually can also track ionizing radiation (high energy photons or even visible light). If their main purpose is radiation measurement, they are called radiation detector, but as photons can also be seen as (massless) particles, the term particle detector is still correct.

Examples and types

Many of the detectors invented and used so far may are ionization detectors (of which gaseous ionization detectors and semiconductor detectors are most typical) and scintillation detectors; but other, completely different principles have also been applied, like Cherenkov light and transition radiation.

Historical Examples Detectors for Radiation Protection Commonly used detectors for Particle and Nuclear Physics

Modern detectors

Main article: Hermetic detector
Modern detectors in particle physics combine several of the above elements in layers much like an onion.

Installations of particle detectors

At colliders

Without colliders

See also

External articles and references

Filmstrips
  • "Radiation detectors". H. M. Stone Productions, Schloat. Tarrytown, N.Y., Prentice-Hall Media, 1972.
General Information
Particle physics is a branch of physics that studies the elementary constituents of matter and radiation, and the interactions between them. It is also called "high energy physics"
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For the novel, see .


In particle physics, an elementary particle or fundamental particle is a not known to have substructure; that is, it is not known to be made up of smaller particles.
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Radioactive decay is the process in which an unstable atomic nucleus loses energy by emitting radiation in the form of particles or electromagnetic waves. This decay, or loss of energy, results in an atom of one type, called the parent nuclide
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Cosmic rays are energetic particles originating from space that impinge on Earth's atmosphere. Almost 90% of all the incoming cosmic ray particles are protons, about 9% are helium nuclei (alpha particles) and about 1% are electrons.
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particle accelerator is a device that uses electric fields to propel electrically charged particles to high speeds and to contain them. An ordinary CRT television set is a simple form of accelerator. There are two basic types: linear (i.e.
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counter is a device which stores (and sometimes displays) the number of times a particular event or process has occurred, often in relationship to a clock signal. In practice, there are two types of counters:
  • up counters which increase (increment) in value

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Photon

Photons emitted in a coherent beam from a laser
Composition: Elementary particle
Family: Boson
Group: Gauge boson
Interaction: Electromagnetic
Theorized: Albert Einstein (1905–17)
Symbol: or
Mass: 0[1]
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Light is electromagnetic radiation of a wavelength that is visible to the eye (visible light). In a scientific context, the word "light" is sometimes used to refer to the entire electromagnetic spectrum.
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In particle physics, gaseous ionization detectors are detectors designed to seek the presence of particles (a particle detector). If a particle has enough energy to ionize a gas, the resulting electrons emitted can cause a current flow which can be measured in different ways.
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A semiconductor detector is a device that uses a semiconductor (usually silicon or germanium) to detect traversing charged particles or the absorption of photons. In the field of particle physics, these detectors are usually known as silicon detectors.
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scintillator is a substance that absorbs high energy (ionizing) electromagnetic or charged particle radiation then, in response, fluoresces photons at a characteristic Stokes-shifted (longer) wavelength, releasing the previously absorbed energy.
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bubble chamber is a vessel filled with a superheated transparent liquid (most often liquid hydrogen) 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.
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cloud chamber, also known as the Wilson chamber, is used for detecting particles of ionizing radiation. In its most basic form, a cloud chamber is a sealed environment containing a supercooled, supersaturated water vapour.
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A dosimeter is any device used to measure an individual's exposure to a hazardous environment, particularly when the hazard is cumulative over long intervals of time, or one's lifetime.
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In an electroscope is a scientific instrument that is used to detect the presence and magnitude of electric charge on a body.

There are two classical types of electroscopes:
  • Pith-ball electroscope; and
  • Gold-leaf electroscope.

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In particle physics, a calorimeter is an experimental apparatus that measures the energy of particles. Most particles enter the calorimeter and initiate a particle shower and the particles' energy is deposited in the calorimeter, collected, and measured.
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A time of flight (TOF) detector is a particle detector which can discriminate between a lighter and a heavier elementary particle of same momentum using their time of flight between two scintillators.
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Photographic plates were one of the earliest forms of photographic film, in which a light-sensitive emulsion of silver salts was applied to a glass plate. This form of photographic emulsion largely faded from the consumer market in the early years of the 20th century, as more
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A Cherenkov (Čerenkov) detector is a particle detector utilizing the mass-dependent threshold energy of Čherenkov radiation. This allows a discrimination between a lighter particle (which does radiate) and a heavier particle (which does not radiate).
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A transition radiation detector (TRD) is a particle detector utilizing the -dependent threshold of transition radiation in a stratified material. It contains many layers of materials with different indices of refraction.
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A scintillation counter measures ionizing radiation. The sensor, called a scintillator, consists of a transparent crystal, usually phosphor, plastic (usually containing anthracene), or organic liquid (see liquid scintillation counting) that fluoresces when struck by ionizing
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Photomultiplier tubes (photomultipliers or PMTs for short) are extremely sensitive detectors of light in the ultraviolet, visible and near infrared. These detectors multiply the signal produced by incident light by as much as 108
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photodiode is a semiconductor diode that functions as a photodetector. Photodiodes are packaged with either a window or optical fibre connection, in order to let in the light to the sensitive part of the device. They may also be used without a window to detect vacuum UV or X-rays.
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Avalanche photodiodes (APDs) are photodetectors that can be regarded as the semiconductor analog to photomultipliers. By applying a high reverse bias voltage (typically 100-200 V in silicon), APDs show an internal current gain effect (around 100) due to impact ionization (avalanche
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A Lucas cell is a type of scintillation particle detector. It is used to grab a gas sample, filter out the radioactive particulates through a special filter and then count the radioactive decay. It is frequently used to measure radon gas concentrations.
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A semiconductor detector is a device that uses a semiconductor (usually silicon or germanium) to detect traversing charged particles or the absorption of photons. In the field of particle physics, these detectors are usually known as silicon detectors.
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In particle physics, gaseous ionization detectors are detectors designed to seek the presence of particles (a particle detector). If a particle has enough energy to ionize a gas, the resulting electrons emitted can cause a current flow which can be measured in different ways.
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An ionization chamber is a device used for two major purposes: detecting particles in air (as in a smoke detector), and for detection or measurement of ionizing radiation.
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A proportional counter is a measurement device to count particles of ionizing radiation and measure their energy.

A proportional counter is a type of Gaseous ionization detector - it works on the same principal as the Geiger-Müller counter, but uses a lower operating voltage.
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A Geiger-Müller tube (or GM tube) is the sensing element of a Geiger counter instrument that can detect a single particle of ionizing radiation, and typically produce an audible click for each.
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