Isotope separation is the process of concentrating specific isotopes of a chemical element by removing other isotopes. The use of the nuclides produced is varied. The largest variety is used in research. By tonnage, separating natural uranium into enriched uranium and depleted uranium is the largest application. In the following text, mainly uranium enrichment is considered. This process is crucial in the manufacture of uranium fuel for nuclear power plants, and is also required for the creation of uranium-based nuclear weapons. Plutonium-based weapons use plutonium produced in a nuclear reactor, which must be operated in such a way as to produce plutonium already of suitable isotopic mix or grade.
In nuclear physics, an atomic nucleus is called a halo nucleus or is said to have a nuclear halo when it has a core nucleus surrounded by a "halo" of orbiting protons or neutrons, which makes the radius of the nucleus appreciably larger than that predicted by the liquid drop model. Halo nuclei form at the extreme edges of the table of nuclides — the neutron drip line and proton drip line — and have short half-lives, measured in milliseconds. These nuclei are studied shortly after their formation in an ion beam.
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.
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.
A radio-frequency quadrupole (RFQ) beam cooler is a device for particle beam cooling, especially suited for ion beams. It lowers the temperature of a particle beam by reducing its energy dispersion and emittance, effectively increasing its brightness (brilliance). The prevalent mechanism for cooling in this case is buffer-gas cooling, whereby the beam loses energy from collisions with a light, neutral and inert gas. The cooling must take place within a confining field in order to counteract the thermal diffusion that results from the ion-atom collisions.
Klaus Blaum is a German physicist and director at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany.
Total absorption spectroscopy is a measurement technique that allows the measurement of the gamma radiation emitted in the different nuclear gamma transitions that may take place in the daughter nucleus after its unstable parent has decayed by means of the beta decay process. This technique can be used for beta decay studies related to beta feeding measurements within the full decay energy window for nuclei far from stability.
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.
CERN-MEDical Isotopes Collected from ISOLDE (MEDICIS) is a facility located in the Isotope Separator Online DEvice (ISOLDE) facility at CERN, designed to produce high-purity isotopes for developing the practice of patient diagnosis and treatment. The facility was initiated in 2010, with its first radioisotopes (terbium-155) produced on 12 December 2017.
The Collinear Resonance Ionization Spectroscopy (CRIS) experiment is located in the ISOLDE facility at CERN. The experiment aims to study ground-state properties of exotic nuclei and produce high purity isomeric beams used for decay studies. CRIS does this by using the high resolution technique of fast beam collinear laser spectroscopy, with the high efficiency technique of resonance ionization.
The Emission Channeling with Short-Lived Isotopes (EC-SLI) experiment is a permanent setup located within the ISOLDE facility and CERN. The purpose of the experiment is to study lattice locations of dopants and impurities in both single crystals and epitaxial thin films. The experiment uses short-lived isotopes from the ISOLDE on-line beamline, as well as longer-lived isotopes from three off-line beamlines.
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 LUCRECIA experiment is a permanent experimental setup at the ISOLDE facility at CERN. The purpose of LUCRECIA is to analyse nuclear structure and use this to confirm theoretical models and make stellar predictions. The experiment is based on a Total Absorption gamma Spectrometer (TAS) designed to measure beta ray feeding.
The Miniballexperiment is a gamma-ray spectroscopy setup regularly located in the ISOLDE facility at CERN, along with other locations including GSI, Cologne, PSI and RIKEN (HiCARI). Miniball is a high-resolution germanium detector array, specifically designed to work with low-intensity radioactive ion beams (RIB) post-accelerated by HIE-ISOLDE, to analyse the decays of short-lived nuclei with the capability of Doppler correction. The array has been used for successful Coulomb-excitation and transfer-reaction experiments with exotic RIBs. Results from Miniball experiments have been used to determine and probe nuclear structure.
The Multi Ion Reflection Apparatus for CoLlinear Spectroscopy (MIRACLS) is a permanent experiment setup being constructed at the ISOLDE facility at CERN. The purpose of the experiment is to measure properties of exotic radioisotopes, from precise measurements of their hyperfine structure. MIRACLS will use laser spectroscopy for measurements, aiming to increase the sensitivity of the technique by trapping ion bunches in an ion trap.
The Scattering Experiments Chamber (SEC) experiment is a permanent experimental setup located in the ISOLDE facility at CERN. The station facilitates diversified reaction experiments, especially for studying low-lying resonances in light atomic nuclei via transfer reactions. SEC does not detect gamma radiation, and therefore is complementary to the ISOLDE Solenoidal Spectrometer (ISS) and Miniball experiments.
The Versatile Ion polarisation Technique Online (VITO) experiment is a permanent experimental setup located in the ISOLDE facility at CERN, in the form of a beamline. The purpose of the beamline is to perform a wide range of studies using spin-polarised short-lived atomic nuclei. VITO uses circularly-polarised laser light to obtain polarised radioactive beams of different isotopes delivered by ISOLDE. These have already been used for weak-interaction studies, biological investigations, and more recently nuclear structure research. The beamline is located at the site of the former Ultra High Vacuum (UHV) beamline hosting ASPIC.
