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A hodoscope (from the Greek "hodos" for way or path, and "skopos" an observer) is an instrument used in particle detectors to detect passing charged particles and determine their trajectories. Hodoscopes are characterized by being made up of many segments; the combination of which segments record a detection is then used to infer where the particle passed through hodoscope.
The typical detector segment is a piece of scintillating material, which emits light when a particle passes through it. The scintillation light can be converted to an electrical signal either by a photomultiplier tube (PMT) or a PIN diode. If a segment measures some significant amount of light, the experimenter can infer that a particle passed through that segment. In addition to coordinate information, for some systems the strength of the light can be proportional to the deposited energy. By doing necessary calibrations, the deposited energy can be determined, which then can be used to infer information about the original particle's energy.
As an example: a simple hodoscope might be used to determine where a particle crossed a plane or a wall. In this case, the experimenter could use two segments shaped like strips, arranged in two layers. One layer of strips could be arranged horizontally, while a second layer could be arranged vertically. A particle passing through the wall would hit a strip in each layer; the vertical strip would reveal the particle's horizontal position when it crossed the wall, while the horizontal strip would indicate the particle's vertical position.
Hodoscopes are some of the simplest detectors for tracking charged particles. However, their spatial resolution is limited by the segment size. In applications where the spatial resolution is very important, hodoscopes have been superseded by other detectors such as drift chambers and time projection chambers.
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.
The Compact Muon Solenoid (CMS) experiment is one of two large general-purpose particle physics detectors built on the Large Hadron Collider (LHC) at CERN in Switzerland and France. The goal of the CMS experiment is to investigate a wide range of physics, including the search for the Higgs boson, extra dimensions, and particles that could make up dark matter.
The BaBar experiment, or simply BaBar, is an international collaboration of more than 500 physicists and engineers studying the subatomic world at energies of approximately ten times the rest mass of a proton (~10 GeV). Its design was motivated by the investigation of charge-parity violation. BaBar is located at the SLAC National Accelerator Laboratory, which is operated by Stanford University for the Department of Energy in California.
A semiconductor detector in ionizing radiation detection physics is a device that uses a semiconductor to measure the effect of incident charged particles or photons.
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. The technique was an improvement over the bubble chamber particle detection method, which used photographic techniques, as it allowed high speed electronics to track the particle path.
The Underground Area 2 (UA2) experiment was a high-energy physics experiment at the Proton-Antiproton Collider — a modification of the Super Proton Synchrotron (SPS) — at CERN. The experiment ran from 1981 until 1990, and its main objective was to discover the W and Z bosons. UA2, together with the UA1 experiment, succeeded in discovering these particles in 1983, leading to the 1984 Nobel Prize in Physics being awarded to Carlo Rubbia and Simon van der Meer. The UA2 experiment also observed the first evidence for jet production in hadron collisions in 1981, and was involved in the searches of the top quark and of supersymmetric particles. Pierre Darriulat was the spokesperson of UA2 from 1981 to 1986, followed by Luigi Di Lella from 1986 to 1990.
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 particle trajectory or interaction.
Gamma-ray spectroscopy is the qualitative study of the energy spectra of gamma-ray sources, such as in the nuclear industry, geochemical investigation, and astrophysics. Gamma-ray spectrometry, on the other hand, is the method used to acquire a quantitative spectrum measurement.
The Collider Detector at Fermilab (CDF) experimental collaboration studies high energy particle collisions from the Tevatron, the world's former highest-energy particle accelerator. The goal is to discover the identity and properties of the particles that make up the universe and to understand the forces and interactions between those particles.
ALICE is one of nine detector experiments at the Large Hadron Collider at CERN. The experiment is designed to study the conditions that are thought to have existed immediately after the Big Bang by measuring properties of quark-gluon plasma.
A neutrino detector is a physics apparatus which is designed to study neutrinos. Because neutrinos only weakly interact with other particles of matter, neutrino detectors must be very large to detect a significant number of neutrinos. Neutrino detectors are often built underground, to isolate the detector from cosmic rays and other background radiation. The field of neutrino astronomy is still very much in its infancy – the only confirmed extraterrestrial sources as of 2018 are the Sun and the supernova 1987A in the nearby Large Magellanic Cloud. Another likely source is the blazar TXS 0506+056 about 3.7 billion light years away. Neutrino observatories will "give astronomers fresh eyes with which to study the universe".
In particle physics, a hermetic detector is a particle detector designed to observe all possible decay products of an interaction between subatomic particles in a collider by covering as large an area around the interaction point as possible and incorporating multiple types of sub-detectors. They are typically roughly cylindrical, with different types of detectors wrapped around each other in concentric layers; each detector type specializes in particular particles so that almost any particle will be detected and identified. Such detectors are called "hermetic" because they are constructed so as the motion of particles are ceased at the boundaries of the chamber without any moving beyond due to the seals; the name "4π detector" comes from the fact that such detectors are designed to cover nearly all of the 4π steradians of solid angle around the interaction point; in terms of the standard coordinate system used in collider physics, this is equivalent to coverage of the entire range of azimuthal angle and pseudorapidity. In practice, particles with pseudorapidity above a certain threshold cannot be measured since they are too nearly parallel to the beamline and can thus pass through the detector. This limit on the pseudorapidity ranges which can be observed forms part of the acceptance of the detector ; broadly speaking, the main design objective of a hermetic detector is to maximise acceptance, i.e. to ensure that the detector is able to measure as large a phase space region as possible.
T2K is a particle physics experiment studying the oscillations of the accelerator neutrinos. The experiment is conducted in Japan by the international cooperation of about 500 physicists and engineers with over 60 research institutions from several countries from Europe, Asia and North America and it is a recognized CERN experiment (RE13). T2K collected data within its first phase of operation from 2010 till 2021. The second phase of data taking is expected to start in 2023 and last until commencement of the successor of T2K – the Hyper-Kamiokande experiment in 2027.
MACRO was a particle physics experiment located at the Laboratori Nazionali del Gran Sasso in Abruzzo, Italy. MACRO was proposed by 6 scientific institutions in the United States and 6 Italian institutions.
The NA58 experiment, or COMPASS is a 60-metre-long fixed-target experiment at the M2 beam line of the SPS at CERN. The experimental hall is located at the CERN North Area, close to the French village of Prévessin-Moëns. The experiment is a two-staged spectrometer with numerous tracking detectors, particle identification and calorimetry. The physics results are extracted by recording and analysing the final states of the scattering processes.
The Telescope Array project is an international collaboration involving research and educational institutions in Japan, The United States, Russia, South Korea, and Belgium. The experiment is designed to observe air showers induced by ultra-high-energy cosmic ray using a combination of ground array and air-fluorescence techniques. It is located in the high desert in Millard County, Utah, United States, at about 1,400 meters (4,600 ft) above sea level.
The NA62 experiment is a fixed-target particle physics experiment in the North Area of the SPS accelerator at CERN. The experiment was approved in February 2007. Data taking began in 2015, and the experiment is expected to become the first in the world to probe the decays of the charged kaon with probabilities down to 10−12. The experiment's spokesperson is Cristina Lazzeroni. The collaboration involves 333 individuals from 30 institutions and 13 countries around the world.
PERDaix is a novel, small and light weight magnetic spectrometer to measure the charge and mass dependent solar modulation periodically for deeper understanding of cosmic rays. For a better understanding of sources and acceleration of cosmic particles direct measurements of cosmic rays are necessary. Also for a better understanding of the solar modulation which is expected to follow the 22-year solar cycle, time dependent measurements are needed. PERDaix is a newly designed detector which is constructed by the Department of Physics 1b, RWTH Aachen University. Being proposed to the German Space Agency in November 2009 for a participation in the BEXUS Program after a first canceled flight attempt in October 2010 the actual flight took place as a post-BEXUS-campaign flight opportunity in November 2010.
The LUX-ZEPLIN (LZ) Experiment is a next-generation dark matter direct detection experiment hoping to observe weakly interacting massive particles (WIMP) scatters on nuclei. It was formed in 2012 by combining the LUX and ZEPLIN groups. It is currently a collaboration of 30 institutes in the US, UK, Portugal and South Korea. The experiment is located at the Sanford Underground Research Facility (SURF) in South Dakota, and is managed by the United States Department of Energy's (DOE) Lawrence Berkeley National Lab.
The Beijing Spectrometer III is a particle physics experiment at the Beijing Electron–Positron Collider II at the Institute of High Energy Physics (IHEP). It is designed to study the physics of charm, charmonium, and light hadron decays. It also performs studies of the tau lepton, tests of QCD, and searches for physics beyond the Standard Model. The experiment started collecting data in the summer of 2008.