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 fundamental particles in the universe are classified in the Standard Model as fermions and bosons. There are three generations of fermions, although ordinary matter is made only from the first fermion generation. The first generation consists of up and down quarks which form protons and neutrons, and electrons and electron neutrinos. The three fundamental interactions known to be mediated by bosons are electromagnetism, the weak interaction, and the strong interaction.
In nuclear physics, the island of stability is a predicted set of isotopes of superheavy elements that may have considerably longer half-lives than known isotopes of these elements. It is predicted to appear as an "island" in the chart of nuclides, separated from known stable and long-lived primordial radionuclides. Its theoretical existence is attributed to stabilizing effects of predicted "magic numbers" of protons and neutrons in the superheavy mass region.
The National Superconducting Cyclotron Laboratory (NSCL), located on the campus of Michigan State University was a rare isotope research facility in the United States. Established in 1963, the cyclotron laboratory has been succeeded by the Facility for Rare Isotope Beams, a linear accelerator providing beam to the same detector halls.
Proton emission is a rare type of radioactive decay in which a proton is ejected from a nucleus. Proton emission can occur from high-lying excited states in a nucleus following a beta decay, in which case the process is known as beta-delayed proton emission, or can occur from the ground state of very proton-rich nuclei, in which case the process is very similar to alpha decay. For a proton to escape a nucleus, the proton separation energy must be negative —the proton is therefore unbound, and tunnels out of the nucleus in a finite time. The rate of proton emission is governed by the nuclear, Coulomb, and centrifugal potentials of the nucleus, where centrifugal potential affects a large part of the rate of proton emission. Half-life of proton emission is affected by the proton energy and its orbital angular momentum. Proton emission is not seen in naturally occurring isotopes; proton emitters can be produced via nuclear reactions, usually using linear particle accelerators.
In nuclear physics, a magic number is a number of nucleons such that they are arranged into complete shells within the atomic nucleus. As a result, atomic nuclei with a 'magic' number of protons or neutrons are much more stable than other nuclei. The seven most widely recognized magic numbers as of 2019 are 2, 8, 20, 28, 50, 82, and 126.
Unbibium, also known as element 122 or eka-thorium, is a hypothetical chemical element; it has placeholder symbol Ubb and atomic number 122. Unbibium and Ubb are the temporary systematic IUPAC name and symbol respectively, which are used until the element is discovered, confirmed, and a permanent name is decided upon. In the periodic table of the elements, it is expected to follow unbiunium as the second element of the superactinides and the fourth element of the 8th period. Similarly to unbiunium, it is expected to fall within the range of the island of stability, potentially conferring additional stability on some isotopes, especially 306Ubb which is expected to have a magic number of neutrons (184).
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 1000 experimentalists around the world are coming to ISOLDE to perform typically 50 different experiments per year.
The Argonne Tandem Linac Accelerator System (ATLAS) is a U.S. Department of Energy scientific user facility at Argonne National Laboratory. ATLAS is the first superconducting linear accelerator for heavy ions at energies in the vicinity of the Coulomb barrier and is open to scientists from all over the world.
The Variable Energy Cyclotron Centre (VECC) is a research and development unit of the Department of Atomic Energy. The VECC is located in Kolkata, India and performs research in basic and applied nuclear sciences and development of the latest nuclear particle accelerators. It has a collaboration with the European Organization for Nuclear Research. The Centre houses a 224 cm cyclotron—the first of its kind in India—which has been operational since 16 June 1977. It provides proton, deuteron, alpha particle and heavy ion beams of various energies to other institutions.
Although there are nine known isotopes of helium (2He), only helium-3 and helium-4 are stable. All radioisotopes are short-lived, the longest-lived being 6
He
with a half-life of 806.92(24) milliseconds. The least stable is 10
He
, with a half-life of 260(40) yoctoseconds, although it is possible that 2
He
may have an even shorter half-life.
Electron scattering occurs when electrons are displaced from their original trajectory. This is due to the electrostatic forces within matter interaction or, if an external magnetic field is present, the electron may be deflected by the Lorentz force. This scattering typically happens with solids such as metals, semiconductors and insulators; and is a limiting factor in integrated circuits and transistors.
Calcium-48 is a scarce isotope of calcium containing 20 protons and 28 neutrons. It makes up 0.187% of natural calcium by mole fraction. Although it is unusually neutron-rich for such a light nucleus, its beta decay is extremely hindered, and so the only radioactive decay pathway that it has been observed to undergo is the extremely rare process of double beta decay. Its half-life is about 6.4×1019 years, so for all practical purposes it can be treated as stable. One factor contributing to this unusual stability is that 20 and 28 are both magic numbers, making 48Ca a "doubly magic" nucleus.
A gamma ray, also known as gamma radiation (symbol γ or ), is a penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nuclei. It consists of the shortest wavelength electromagnetic waves, typically shorter than those of X-rays. With frequencies above 30 exahertz (3×1019 Hz), it imparts the highest photon energy. Paul Villard, a French chemist and physicist, discovered gamma radiation in 1900 while studying radiation emitted by radium. In 1903, Ernest Rutherford named this radiation gamma rays based on their relatively strong penetration of matter; in 1900 he had already named two less penetrating types of decay radiation (discovered by Henri Becquerel) alpha rays and beta rays in ascending order of penetrating power.
Alpha particles, also called alpha rays or alpha radiation, consist of two protons and two neutrons bound together into a particle identical to a helium-4 nucleus. They are generally produced in the process of alpha decay, but may also be produced in other ways. Alpha particles are named after the first letter in the Greek alphabet, α. The symbol for the alpha particle is α or α2+. Because they are identical to helium nuclei, they are also sometimes written as He2+
or 4
2He2+
indicating a helium ion with a +2 charge. Once the ion gains electrons from its environment, the alpha particle becomes a normal helium atom 4
2He.
The Soreq Applied Research Accelerator Facility (SARAF) is a multi-user and versatile particle accelerator facility. It is on a proton/deuteron RF superconducting linear accelerator, with variable energy and a continuous wave (CW) high ion current, and located at the Soreq Nuclear Research Center.
The Synchro-Cyclotron, or Synchrocyclotron (SC), built in 1957, was CERN’s first accelerator. It was 15.7 metres (52 ft) in circumference and provided beams for CERN's first experiments in particle and nuclear physics. It accelerated particles to energies up to 600 MeV. The foundation stone of CERN was laid at the site of the Synchrocyclotron by the first Director-General of CERN, Felix Bloch. After its remarkably long 33 years of service time, the SC was decommissioned in 1990. Nowadays it accepts visitors as an exhibition area in CERN.
The Laboratori Nazionali di Legnaro is one of the four major research centers of the Italian National Institute for Nuclear Physics (INFN). The primary focus of research at this laboratory is in the fields of nuclear physics and nuclear astrophysics, where five accelerators are currently used. It is one of the most important facilities in Italy for research in these fields. The main future project of the laboratory is the Selective Production of Exotic Species (SPES), in which various radionuclides will be produced for research and medicinal purposes.
Alexandre Obertelli is a French experimental nuclear physicist and Alexander von Humboldt Professor of Experimental Nuclear Structure Physics at the Institute of Nuclear Physics of the Technische Universität Darmstadt.
