In experimental and applied

particle physics Particle physics or high energy physics is the study of fundamental particles and forces that constitute matter and radiation. The fundamental particles in the universe are classified in the Standard Model as fermions (matter particles) an ...

nuclear physics Nuclear physics is the field of physics that studies atomic nuclei and their constituents and interactions, in addition to the study of other forms of nuclear matter. Nuclear physics should not be confused with atomic physics, which studies the ...

, and nuclear engineering, a particle detector, also known as a radiation detector, is a device used to detect, track, and/or identify ionizing

particle In the Outline of physical science, physical sciences, a particle (or corpuscule in older texts) is a small wikt:local, localized physical body, object which can be described by several physical property, physical or chemical property, chemical ...

s, such as those produced by

nuclear decay Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is consid ...

cosmic radiation Cosmic rays are high-energy particles or clusters of particles (primarily represented by protons or atomic nuclei) that move through space at nearly the speed of light. They originate from the Sun, from outside of the Solar System in our own ...

, or reactions in a

particle accelerator A particle accelerator is a machine that uses electromagnetic fields to propel charged particles to very high speeds and energies, and to contain them in well-defined beams. Large accelerators are used for fundamental research in particle ...

. Detectors can measure the particle energy and other attributes such as momentum, spin, charge, particle type, in addition to merely registering the presence of the particle.

Examples and types

Many of the detectors invented and used so far are ionization detectors (of which

gaseous ionization detector Gaseous ionization detectors are radiation detection instruments used in particle physics to detect the presence of ionizing particles, and in radiation protection applications to measure ionizing radiation. They use the ionising effect of radi ...

s and

semiconductor detector A semiconductor detector in ionizing radiation detection physics is a device that uses a semiconductor (usually silicon or germanium) to measure the effect of incident charged particles or photons. Semiconductor detectors find broad applicati ...

s are most typical) and

scintillation detector Scintillation can refer to: *Scintillation (astronomy), atmospheric effects which influence astronomical observations *Interplanetary scintillation, fluctuations of radio waves caused by the solar wind *Scintillation (physics), a flash of light pro ...

s; but other, completely different principles have also been applied, like Čerenkov light and transition radiation. Alpha radiation in a cloud chamber

Historical examples *

Bubble chamber A 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 196 ...

* Wilson cloud chamber (diffusion chamber) *

Photographic plate Photographic plates preceded photographic film as a capture medium in photography, and were still used in some communities up until the late 20th century. The light-sensitive emulsion of silver salts was coated on a glass plate, typically thinn ...

;Detectors for radiation protection The following types of particle detector are widely used for radiation protection, and are commercially produced in large quantities for general use within the nuclear, medical, and environmental fields. *

Dosimeter A radiation dosimeter is a device that measures dose uptake of external ionizing radiation. It is worn by the person being monitored when used as a personal dosimeter, and is a record of the radiation dose received. Modern electronic personal dos ...

Electroscope The electroscope is an early scientific instrument used to detect the presence of electric charge on a body. It detects charge by the movement of a test object due to the Coulomb electrostatic force on it. The amount of charge on an object is ...

(when used as a portable dosimeter) *

Gaseous ionization detector Gaseous ionization detectors are radiation detection instruments used in particle physics to detect the presence of ionizing particles, and in radiation protection applications to measure ionizing radiation. They use the ionising effect of radi ...

Geiger counter A Geiger counter (also known as a Geiger–Müller counter) is an electronic instrument used for detecting and measuring ionizing radiation. It is widely used in applications such as radiation dosimetry, radiological protection, experimental ph ...

Ionization chamber The ionization chamber is the simplest type of gas-filled radiation detector, and is widely used for the detection and measurement of certain types of ionizing radiation, including X-rays, gamma rays, and beta particles. Conventionally, the term ...

Proportional counter The proportional counter is a type of gaseous ionization detector device used to measure particles of ionizing radiation. The key feature is its ability to measure the energy of incident radiation, by producing a detector output pulse that is ''prop ...

Scintillation counter A scintillation counter is an instrument for detecting and measuring ionizing radiation by using the excitation effect of incident radiation on a scintillating material, and detecting the resultant light pulses. It consists of a scintillator w ...

Semiconductor detector A semiconductor detector in ionizing radiation detection physics is a device that uses a semiconductor (usually silicon or germanium) to measure the effect of incident charged particles or photons. Semiconductor detectors find broad applicati ...

Commonly used detectors for particle and nuclear physics *

***

Multiwire proportional chamber A wire chamber or multi-wire proportional chamber is a type of proportional counter that detects charged particles and photons and can give positional information on their trajectory, by tracking the trails of gaseous ionization. was located via ...

***

Drift chamber A wire chamber or multi-wire proportional chamber is a type of proportional counter that detects charged particles and photons and can give positional information on their trajectory, by tracking the trails of gaseous ionization. was located via ...

***

Time projection chamber In physics, a time projection chamber (TPC) is a type of particle detector that uses a combination of electric fields and magnetic fields together with a sensitive volume of gas or liquid to perform a three-dimensional reconstruction of a particl ...

***

Micropattern gaseous detector Micropattern gaseous detectors (MPGDs) are a group of gaseous ionization detectors Gaseous ionization detectors are radiation detection instruments used in particle physics to detect the presence of ionizing particles, and in radiation protecti ...

** Geiger–Müller tube **

Spark chamber {{short description, Charged particle detector A spark chamber is a particle detector: a device used in particle physics for detecting electrically charged particles. They were most widely used as research tools from the 1930s to the 1960s and have ...

*Solid-state detectors: **

and variants including CCDs ***Silicon Vertex Detector **

Solid-state nuclear track detector A solid-state nuclear track detector or SSNTD (also known as an etched track detector or a dielectric track detector, DTD) is a sample of a solid material (photographic emulsion, crystal, glass or plastic) exposed to nuclear radiation (neutrons or c ...

** Cherenkov detector ***

Ring-imaging Cherenkov detector The ring-imaging Cherenkov, or RICH, detector is a device for identifying the type of an electrically charged subatomic particle of known momentum, that traverses a transparent refractive medium, by measurement of the presence and characteristics ...

(RICH) **

and associated

photomultiplier A photomultiplier is a device that converts incident photons into an electrical signal. Kinds of photomultiplier include: * Photomultiplier tube, a vacuum tube converting incident photons into an electric signal. Photomultiplier tubes (PMTs for sho ...

photodiode A photodiode is a light-sensitive semiconductor diode. It produces current when it absorbs photons. The package of a photodiode allows light (or infrared or ultraviolet radiation, or X-rays) to reach the sensitive part of the device. The packag ...

, or

avalanche photodiode An avalanche photodiode (APD) is a highly sensitive semiconductor photodiode detector that exploits the photoelectric effect to convert light into electricity. From a functional standpoint, they can be regarded as the semiconductor analog of phot ...

***

Lucas cell A Lucas cell is a type of scintillation counter. It is used to acquire a gas sample, filter out the radioactive particulates through a special filter and then count the radioactive decay. The inside of the gas chamber is coated with ZnS( Ag) - a ...

***

Time-of-flight detector 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. The first of the scintillators activates a clo ...

Transition radiation detector A transition radiation detector (TRD) is a particle detector using the \gamma-dependent threshold of transition radiation in a stratified material. It contains many layers of materials with different indices of refraction. At each interface betwe ...

Calorimeter A calorimeter is an object used for calorimetry, or the process of measuring the heat of chemical reactions or physical changes as well as heat capacity. Differential scanning calorimeters, isothermal micro calorimeters, titration calorimete ...

* Microchannel plate detector *

Neutron detector Neutron detection is the effective detection of neutrons entering a well-positioned detector. There are two key aspects to effective neutron detection: hardware and software. Detection hardware refers to the kind of neutron detector used (the most ...

Modern detectors

Modern detectors in particle physics combine several of the above elements in layers much like an

onion An onion (''Allium cepa'' L., from Latin ''cepa'' meaning "onion"), also known as the bulb onion or common onion, is a vegetable that is the most widely cultivated species of the genus ''Allium''. The shallot is a botanical variety of the onion ...

Research particle detectors

Detectors designed for modern accelerators are huge, both in size and in cost. The term ''

counter Counter may refer to: Mathematics and computing * Counter machine, a subclass of register machines * Counter (digital), an electronic device, mechanical device, or computer program for counting * Loop counter, the variable that controls the iter ...

'' is often used instead of ''detector'' when the detector counts the particles but does not resolve its energy or ionization. Particle detectors can also usually track ionizing radiation (high energy

photon A photon () is an elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Photons are massless, so they always ...

s or even visible

light Light or visible light is electromagnetic radiation that can be perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 tera ...

). If their main purpose is radiation measurement, they are called ''radiation detectors'', but as photons are also (massless) particles, the term ''particle detector'' is still correct.

At colliders

*At

CERN The European Organization for Nuclear Research, known as CERN (; ; ), is an intergovernmental organization that operates the largest particle physics laboratory in the world. Established in 1954, it is based in a northwestern suburb of Gene ...

**for the LHC ***

CMS CMS may refer to: Computing * Call management system * CMS-2 (programming language), used by the United States Navy * Code Morphing Software, a technology used by Transmeta * Collection management system for a museum collection * Color manag ...

***

ATLAS An atlas is a collection of maps; it is typically a bundle of maps of Earth or of a region of Earth. Atlases have traditionally been bound into book form, but today many atlases are in multimedia formats. In addition to presenting geographic ...

*** ALICE ***

LHCb The LHCb (Large Hadron Collider beauty) experiment is one of eight particle physics detector experiments collecting data at the Large Hadron Collider at CERN. LHCb is a specialized b-physics experiment, designed primarily to measure the paramet ...

**for the LEP *** Aleph

*** Delphi

*** L3 *** Opal

**for the

SPS SPS may refer to: Law and government * Agreement on the Application of Sanitary and Phytosanitary Measures of the WTO * NATO Science for Peace and Security * Single Payment Scheme, an EU agricultural subsidy * The Standard Procurement System, fo ...

*** The COMPASS Experiment *
Gargamelle
*
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Fermilab Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a United States Department of Energy national laboratory specializing in high-energy particle physics. Since 2007, Fermilab has been operat ...

**for the

Tevatron The Tevatron was a circular particle accelerator (active until 2011) in the United States, at the Fermilab, Fermi National Accelerator Laboratory (also known as ''Fermilab''), east of Batavia, Illinois, and is the second highest energy particle ...

*
CDF
*
D0
**

Mu2e Mu2e, or the Muon-to-Electron Conversion Experiment, is a particle physics experiment at Fermilab in the US. The goal of the experiment is to identify physics beyond the Standard Model, namely, the conversion of muons to electrons without the e ...

*At DESY **for

HERA In ancient Greek religion, Hera (; grc-gre, Ἥρα, Hḗrā; grc, Ἥρη, Hḗrē, label=none in Ionic and Homeric Greek) is the goddess of marriage, women and family, and the protector of women during childbirth. In Greek mythology, she ...

*** H1 *** HERA-B ***

HERMES Hermes (; grc-gre, Ἑρμῆς) is an Olympian deity in ancient Greek religion and mythology. Hermes is considered the herald of the gods. He is also considered the protector of human heralds, travellers, thieves, merchants, and orato ...

***

ZEUS Zeus or , , ; grc, Δῐός, ''Diós'', label=Genitive case, genitive Aeolic Greek, Boeotian Aeolic and Doric Greek#Laconian, Laconian grc-dor, Δεύς, Deús ; grc, Δέος, ''Déos'', label=Genitive case, genitive el, Δίας, ''D� ...

*At BNL **for the RHIC *** PHENIX *** Phobos *
STAR
*At

SLAC SLAC National Accelerator Laboratory, originally named the Stanford Linear Accelerator Center, is a United States Department of Energy National Laboratory operated by Stanford University under the programmatic direction of the U.S. Departme ...

**for th
PeP-II
***

BaBar Babar ( ur, ), also variously spelled as Baber, Babur, and Babor is a male given name of Pashto, and Persian language, Persian origin, and a popular male given name in Pakistan. It is generally taken in reference to the Persian language, Persian ...

**for th
SLC
*

*At

Cornell Cornell University is a private statutory land-grant research university based in Ithaca, New York. It is a member of the Ivy League. Founded in 1865 by Ezra Cornell and Andrew Dickson White, Cornell was founded with the intention to teach an ...

**for CESR ***

CLEO Cleo may refer to: Entertainment * ''Cleo'' (magazine), an Australian magazine established in 1972, now active in Indonesia, Malaysia, Singapore, and Thailand * Cleo (group), a South Korean girl group formed in 1999 * ''Cleo'' (play), by Lawren ...

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UC Irvine UC may refer to: Arts and entertainment * ''University Challenge'', a popular British quiz programme airing on BBC Two ** '' University Challenge (New Zealand)'', the New Zealand version of the British programme * Universal Century, one of the ti ...

Under construction

*For

International Linear Collider The International Linear Collider (ILC) is a proposed linear particle accelerator. It is planned to have a collision energy of 500 GeV initially, with the possibility for a later upgrade to 1000 GeV (1 TeV). Although early proposed ...

(ILC) **

CALICE Calice may refer to: * CALICE (Calorimeter for Linear Collider Experiment), a research and development organization * , an Austrian nobility, Austrian noble family * Calice Becker (fl. 1990–2014), French perfumer * Calice, an alternative name fo ...

(Calorimeter for Linear Collider Experiment)

Without colliders

* Antarctic Muon And Neutrino Detector Array (AMANDA) *

Cryogenic Dark Matter Search The Cryogenic Dark Matter Search (CDMS) is a series of experiments designed to directly detect particle dark matter in the form of Weakly Interacting Massive Particles (or WIMPs). Using an array of semiconductor detectors at millikelvin temperatur ...

(CDMS) *

Super-Kamiokande Super-Kamiokande (abbreviation of Super-Kamioka Neutrino Detection Experiment, also abbreviated to Super-K or SK; ja, スーパーカミオカンデ) is a neutrino observatory located under Mount Ikeno near the city of Hida, Gifu Prefecture ...

XENON Xenon is a chemical element with the symbol Xe and atomic number 54. It is a dense, colorless, odorless noble gas found in Earth's atmosphere in trace amounts. Although generally unreactive, it can undergo a few chemical reactions such as the ...

On spacecraft

Alpha Magnetic Spectrometer The Alpha Magnetic Spectrometer (AMS-02) is a particle physics experiment module that is mounted on the International Space Station (ISS).Kristine Rainey (April 2, 2013)Alpha Magnetic Spectrometer (AMS): How It Works NASA. Retrieved June 2, 20 ...

(AMS) *

JEDI Jedi (), Jedi Knights, or collectively the Jedi Order are the main heroic protagonists of many works of the '' Star Wars'' franchise. Working symbiotically alongside the Old Galactic Republic, and later supporting the Rebel Alliance, the Jedi O ...

(Jupiter Energetic-particle Detector Instrument)

Theoretical Models of Particle Detectors

Beyond their experimental implementations, theoretical models of particle detectors are also of great importance to theoretical physics. These models consider localized non-relativistic quantum systems coupled to a quantum field. They receive the name of particle detectors because when the non-relativistic quantum system is measured in an excited state, one can claim to have detected a particle. The first instance of particle detector models in the literature dates from the 80's, where a particle in a box was introduced by W. G. Unruh in order to probe a quantum field around a black hole. Shortly after,

Bryce DeWitt Bryce Seligman DeWitt (January 8, 1923 – September 23, 2004), was an American theoretical physicist noted for his work in gravitation and quantum field theory. Life He was born Carl Bryce Seligman, but he and his three brothers, including ...

proposed a simplification of the model, giving rise to the Unruh-DeWitt detector model. Beyond their applications to theoretical physics, particle detector models are related to experimental fields such as

quantum optics Quantum optics is a branch of atomic, molecular, and optical physics dealing with how individual quanta of light, known as photons, interact with atoms and molecules. It includes the study of the particle-like properties of photons. Photons have b ...

, where atoms can be used as detectors for the quantum electromagnetic field via the light-matter interaction. From a conceptual side, particle detectors also allow one to formally define the concept of particles without relying on asymptotic states, or representations of a quantum field theory. As M. Scully puts it, from an operational viewpoint one can state that "a particle is what a particle detector detects", which in essence defines a particle as the detection of excitations of a quantum field.

References

* * *