SuperHILAC

SuperHILAC. The Super Heavy Ion Linear Accelerator was a major linear particle accelerator located at the Lawrence Berkeley National Laboratory in Berkeley, California. Operational from 1972 to 1992, it was a premier facility for heavy ion physics, enabling groundbreaking research in nuclear physics and the discovery of new chemical elements. Its design and capabilities made it a critical precursor to later, more powerful accelerators like the Relativistic Heavy Ion Collider.

History and Development

The SuperHILAC was conceived as an upgrade to the original HILAC (Heavy Ion Linear Accelerator), which began operation in 1957 under the direction of scientists like Albert Ghiorso. Funded by the United States Department of Energy, the project aimed to accelerate much heavier ions to higher energies. Key figures in its development included Roger Batzel and a team of engineers from the Lawrence Radiation Laboratory. Its construction coincided with a period of intense international competition in heavy ion research, particularly with institutions in the Soviet Union and West Germany. The accelerator achieved first beam in 1972, marking a significant advancement for the Lawrence Berkeley National Laboratory and the broader field of nuclear science.

Technical Design and Operation

The SuperHILAC was a large linear particle accelerator approximately 300 feet long, utilizing a combination of radio frequency cavities and powerful electromagnets to accelerate ions. It operated on the principle of Wideröe linear accelerator structures, employing alternating electric fields to progressively increase particle energy. The machine could accelerate a wide range of ions, from light elements like oxygen to very heavy ones like uranium, stripping them of their electrons to create highly charged beams. Critical to its operation were advanced ion source technologies and sophisticated beam diagnostics systems developed by researchers like Herbert F. Grunder. This design allowed it to deliver intense, high-quality beams for experiments in target halls.

Scientific Contributions and Discoveries

The SuperHILAC was instrumental in the discovery and confirmation of several new chemical elements, extending the periodic table. Researchers, including Albert Ghiorso and Glenn T. Seaborg, used it to produce and identify elements 106, later named seaborgium, and 107, later named bohrium, through reactions with targets of lead and bismuth. It also played a key role in the study of nuclear fusion reactions and the properties of exotic, short-lived isotopes. Experiments conducted there provided fundamental data on nuclear structure and the dynamics of heavy ion collisions, contributing significantly to theories developed by physicists like J. Robert Oppenheimer and institutions such as the Joint Institute for Nuclear Research.

Role in the Bevalac and Relativistic Heavy Ion Collider

A pivotal application of the SuperHILAC was its role as an injector for the Bevalac, a unique combination where its heavy ion beams were further accelerated by the Bevatron synchrotron. This created the world's first facility capable of delivering relativistic heavy ions, enabling pioneering experiments in what would become high-energy nuclear physics. The success of the Bevalac directly influenced the design and scientific case for the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. Technologies and operational expertise gained from running the SuperHILAC, particularly in ion source development and beam handling, were transferred to the team designing the Relativistic Heavy Ion Collider, a facility that would later create the quark–gluon plasma.

Legacy and Decommissioning

After two decades of prolific operation, the SuperHILAC was decommissioned in 1992 to make space and resources for new projects at the Lawrence Berkeley National Laboratory, notably the 88-Inch Cyclotron upgrade and research toward the Facility for Rare Isotope Beams. Its components were repurposed or archived, and the site was eventually cleared. The accelerator's legacy is profound; it established the United States as a leader in heavy ion science and trained a generation of physicists and engineers. Its technological innovations directly paved the way for major subsequent facilities like the Relativistic Heavy Ion Collider and the Large Hadron Collider's heavy ion program, cementing its place in the history of particle physics. Category:Particle accelerators Category:Lawrence Berkeley National Laboratory Category:Nuclear physics