The Argonne Tandem Linac Accelerator System (ATLAS) is a

U.S. Department of Energy The United States Department of Energy (DOE) is an executive department of the U.S. federal government that oversees U.S. national energy policy and manages the research and development of nuclear power and nuclear weapons in the United States ...

scientific user facility at

Argonne National Laboratory Argonne National Laboratory is a science and engineering research national laboratory operated by UChicago Argonne LLC for the United States Department of Energy. The facility is located in Lemont, Illinois, outside of Chicago, and is the lar ...

. ATLAS is the first

superconducting Superconductivity is a set of physical properties observed in certain materials where electrical resistance vanishes and magnetic flux fields are expelled from the material. Any material exhibiting these properties is a superconductor. Unlike ...

linear accelerator A linear particle accelerator (often shortened to linac) is a type of particle accelerator that accelerates charged subatomic particles or ions to a high speed by subjecting them to a series of oscillating electric potentials along a linear b ...

for

heavy ion High-energy nuclear physics studies the behavior of nuclear matter in energy regimes typical of high-energy physics. The primary focus of this field is the study of heavy-ion collisions, as compared to lighter atoms in other particle accelerato ...

s at energies in the vicinity of the

Coulomb barrier The Coulomb barrier, named after Coulomb's law, which is in turn named after physicist Charles-Augustin de Coulomb, is the energy barrier due to electrostatic interaction that two nuclei need to overcome so they can get close enough to undergo a ...

and is open to scientists from all over the world. The ATLAS accelerator at Argonne should not be confused with the

ATLAS experiment ATLAS is the largest general-purpose particle detector experiment at the Large Hadron Collider (LHC), a particle accelerator at CERN (the European Organization for Nuclear Research) in Switzerland. The experiment is designed to take advantage ...

at the

Large Hadron Collider The Large Hadron Collider (LHC) is the world's largest and highest-energy particle collider. It was built by the European Organization for Nuclear Research (CERN) between 1998 and 2008 in collaboration with over 10,000 scientists and hundr ...

at CERN.

How ATLAS works

Ions are generated from one of two sources: the 9-MV electrostatic tandem Van de Graaff accelerator or the Positive Ion Injector, a 12-MV low-velocity

linac A linear particle accelerator (often shortened to linac) is a type of particle accelerator that accelerates charged subatomic particles or ions to a high speed by subjecting them to a series of oscillating electric potentials along a linear ...

and

electron cyclotron resonance Electron cyclotron resonance (ECR) is a phenomenon observed in plasma physics, condensed matter physics, and accelerator physics. It happens when the frequency of incident radiation coincides with the natural frequency of rotation of electrons in ...

(ECR) ion source. The ions are sent from one of these two into the 20-MV 'booster' linac, then to the 20-MV 'ATLAS' linac section. The ATLAS linac is constructed with seven different superconducting resonator designs, each one creating an electromagnetic wave of a different velocity. The ions in the ATLAS linac are aligned into a beam which exits the linac into one of three experimental areas. The experiment areas contain

scattering Scattering is a term used in physics to describe a wide range of physical processes where moving particles or radiation of some form, such as light or sound, are forced to deviate from a straight trajectory by localized non-uniformities (including ...

chambers, spectrometers and spectrographs, beamlines, a gamma-ray facility, and

particle detectors In the physical sciences, a particle (or corpuscule in older texts) is a small localized object which can be described by several physical or chemical properties, such as volume, density, or mass. They vary greatly in size or quantity, from ...

. In 2009, Argonne added a system called CARIBU (Californium Rare Ion Breeder Upgrade) to ATLAS. The system is capable of generating beams of rare isotopes. ATLAS has since received additional upgrades with two enhancements: The Electron Beam Ion System (EBIS), which enables radioactive beams to match the accelerating structures by increasing the ion beam’s positive charge, and the Argonne In-Flight Radioactive Ion Separator (RAISOR), which helps to improve beam purity by separating out specific isotopes. The enhancements of ATLAS with EBIS and RAISOR help scientists probe the structures of exotic elements, study the nature of the nuclear forces, and better understand the production of elements in stars and supernovae.

What ATLAS is for

The energy levels of the ions produced by ATLAS are ideal to study the properties of the

nucleus Nucleus ( : nuclei) is a Latin word for the seed inside a fruit. It most often refers to: *Atomic nucleus, the very dense central region of an atom * Cell nucleus, a central organelle of a eukaryotic cell, containing most of the cell's DNA Nucl ...

. Specifically, scientists use ATLAS to understand reactions between nuclei from very low energies (typically encountered in burning stars) to the very highest energies (encountered soon after the Big Bang). Nuclei with specific properties can be studied to understand fundamental interactions.

What is ATLAS made of

Niobium Niobium is a chemical element with chemical symbol Nb (formerly columbium, Cb) and atomic number 41. It is a light grey, crystalline, and ductile transition metal. Pure niobium has a Mohs hardness rating similar to pure titanium, and it ha ...

is the primary metal used to construct the tube

in the individual in-line resonators. Niobium is used because it is relatively cheap, yet it is a Superconducting, superconductor at relatively high temperatures. Niobium has poor malleability, which makes it difficult to construct the shapes needed for the resonators. The machinists working at ATLAS are some of the only people in the world able to work with niobium to the degree necessary for construction and repair of the ATLAS parts.

Target areas

* Atom Trap at ATLAS *

Canadian Penning Trap Mass Spectrometer The Canadian Penning Trap Mass Spectrometer (CPT) is one of the major pieces of experimental equipment that is installed on the ATLAS superconducting heavy-ion linac facility at the Physics Division of the Argonne National Laboratory. It was develo ...

* Enge Split Pole Spectrograph * Fragment Mass Analyzer * Gammasphere * Helical Orbit Spectrometer (HELIOS) * Large Scattering Chamber

References

* * {{authority control Argonne National Laboratory Nuclear research institutes Particle physics facilities

How ATLAS works

What ATLAS is for

What is ATLAS made of

Target areas

See also

References