In nuclear physics, beta decay (β-decay) is a type of radioactive decay in which an atomic nucleus emits a beta particle, transforming into an isobar of that nuclide. For example, beta decay of a neutron transforms it into a proton by the emission of an electron accompanied by an antineutrino; or, conversely a proton is converted into a neutron by the emission of a positron with a neutrino in what is called positron emission. Neither the beta particle nor its associated (anti-)neutrino exist within the nucleus prior to beta decay, but are created in the decay process. By this process, unstable atoms obtain a more stable ratio of protons to neutrons. The probability of a nuclide decaying due to beta and other forms of decay is determined by its nuclear binding energy. The binding energies of all existing nuclides form what is called the nuclear band or valley of stability. For either electron or positron emission to be energetically possible, the energy release or Q value must be positive.
The neutron is a subatomic particle, symbol
n
or
n0
, which has no electric charge, and a mass slightly greater than that of a proton. Protons and neutrons constitute the nuclei of atoms. Since protons and neutrons behave similarly within the nucleus, they are both referred to as nucleons. Nucleons have a mass of approximately one atomic mass unit, or dalton. Their properties and interactions are described by nuclear physics. Protons and neutrons are not elementary particles; each is composed of three quarks.
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.
Particle physics or high-energy physics is the study of fundamental particles and forces that constitute matter and radiation. The field also studies combinations of elementary particles up to the scale of protons and neutrons, while the study of combination of protons and neutrons is called nuclear physics.
The term p-process (p for proton) is used in two ways in the scientific literature concerning the astrophysical origin of the elements (nucleosynthesis). Originally it referred to a proton capture process which was proposed to be the source of certain, naturally occurring, neutron-deficient isotopes of the elements from selenium to mercury. These nuclides are called p-nuclei and their origin is still not completely understood. Although it was shown that the originally suggested process cannot produce the p-nuclei, later on the term p-process was sometimes used to generally refer to any nucleosynthesis process supposed to be responsible for the p-nuclei.
TRIUMF is Canada's national particle accelerator centre. It is considered Canada's premier physics laboratory, and consistently regarded as one of the world's leading subatomic physics research centres. Owned and operated by a consortium of universities, it is on the south campus of one of its founding members, the University of British Columbia in Vancouver, British Columbia, Canada. It houses the world's largest normal conducting cyclotron, a source of 520 MeV protons, which was named an IEEE Milestone in 2010. Its accelerator-focused activities involve particle physics, nuclear physics, nuclear medicine, materials science, and detector and accelerator development.
The ISOLDE Radioactive Ion Beam Facility, is an on-line isotope separator facility located at the centre of the CERN accelerator complex on the Franco-Swiss border. Created in 1964, the ISOLDE facility started delivering radioactive ion beams (RIBs) to users in 1967. Originally located at the Synchro-Cyclotron (SC) accelerator, the facility has been upgraded several times most notably in 1992 when the whole facility was moved to be connected to CERN's ProtonSynchroton Booster (PSB). ISOLDE is currently the longest-running facility in operation at CERN, with continuous developments of the facility and its experiments keeping ISOLDE at the forefront of science with RIBs. ISOLDE benefits a wide range of physics communities with applications covering nuclear, atomic, molecular and solid-state physics, but also biophysics and astrophysics, as well as high-precision experiments looking for physics beyond the Standard Model. The facility is operated by the ISOLDE Collaboration, comprising CERN and sixteen (mostly) European countries. As of 2019, close to 1,000 experimentalists around the world are coming to ISOLDE to perform typically 50 different experiments per year.
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 the properties of quark-gluon plasma.
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.
The LHCf is a special-purpose Large Hadron Collider experiment for astroparticle physics, and one of nine detectors in the LHC accelerator at CERN. LHCf is designed to study the particles generated in the forward region of collisions, those almost directly in line with the colliding proton beams.
NA61/SHINE is a particle physics experiment at the Super Proton Synchrotron (SPS) at the European Organization for Nuclear Research (CERN). The experiment studies the hadronic final states produced in interactions of various beam particles with a variety of fixed nuclear targets at the SPS energies.
An accelerator-driven subcritical reactor (ADSR) is a nuclear reactor design formed by coupling a substantially subcritical nuclear reactor core with a high-energy proton or electron accelerator. It could use thorium as a fuel, which is more abundant than uranium.
The Soreq Applied Research Accelerator Facility (SARAF) is a superconducting radiofrequency linear accelerator and neutron source, located at the Soreq Nuclear Research Center in Yavne, Israel. Its highly configurable neutron spectrum and produced range of light radionuclides makes it suitable for a range of research topics that previously required a nuclear reactor, such as fusion reactor material studies, producing radionuclides and astrophysics research.
The PUMA AD-9 experiment, at the Antiproton decelerator (AD) facility at CERN, Geneva, aims to look into the quantum interactions and annihilation processes between the antiprotons and the exotic slow-moving nuclei. PUMA's experimental goals require about one billion trapped antiprotons made by AD and ELENA to be transported to the ISOLDE-nuclear physics facility at CERN, which will supply the exotic nuclei. Antimatter has never been transported out of the AD facility before. Designing and building a trap for this transportation is the most challenging aspect for the PUMA collaboration.
Michael C. F. Wiescher is a German-American experimental nuclear physicist and astrophysicist, known for his laboratory research in nuclear physics connected with various astrophysical phenomena such as stellar evolution and explosion environments.
Harold Matthew Spinka Jr. was an American physicist, specializing in experimental particle physics.
The ISOLDE Decay Station (IDS) is a permanent experiment located in the ISOLDE facility at CERN. The purpose of the experiment is to measure decay properties of radioactive isotopes using spectroscopy techniques for a variety of applications, including nuclear engineering and astrophysics. The experimental setup has been operational since 2014.
The ISOLDE Solenoidal Spectrometer (ISS) experiment is a permanent experimental setup located in the ISOLDE facility at CERN. By using an ex-MRI magnet, heavy radioactive ion beams (RIBs) produced by the HIE-ISOLDE post-accelerator are directed at a light target and the kinematics of the reaction is measured. The purpose of the experiment is to measure properties of atomic nuclei replicating the conditions present in some astrophysical processes, such as the production of chemical elements in stars. The experiment will also produce results that provide a better understanding of nucleon-nucleon interactions in highly-unstable, very radioactive (exotic) nuclei.
The high-precision mass spectrometer ISOLTRAP experiment is a permanent experimental setup located at the ISOLDE facility at CERN. The purpose of the experiment is to make precision mass measurements using the time-of-flight (ToF) detection technique. Studying nuclides and probing nuclear structure gives insight into various areas of physics, including astrophysics.
The Underground Area 6 (UA6), also referred to as PHOTONS, 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 1984 to 1990, with the purpose of studying inclusive electromagnetic final states and lambda production in proton-antiproton and proton-proton interactions. Towards the end of its run it focused more on direct-photon and J/ψ production. The experiment is complementary to the UA1, UA2 and CDF experiments.
