The Cosmotron

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Early in the Laboratory's history, the consortium of universities responsible for founding the new research center, decided that Brookhaven should provide unique facilities for high energy physics research. In April 1948, the Atomic Energy Commission approved  a plan for a proton synchrotron to be built at Brookhaven. The new machine would accelerate protons to previously unheard of energies, comparable to those of cosmic rays showering the earth's outer atmosphere. It would be called the Cosmotron.

The Cosmotron

There were accelerators before the Cosmotron, but this machine was the first accelerator in the world to send particles to energies in the billion electron volt, or GeV, region. The Cosmotron reached its full design energy of 3.3 GeV in January 1953.

Not only was the Cosmotron the world's highest energy accelerator, it was also the first synchrotron to provide an external beam of particles for experimentation outside the accelerator itself. Early on, the intensity of the beam extracted for experiments was ten billion protons per pulse. By 1966, intensity had been increased nearly 100 times. 

Behind these energies and intensities was a 75-foot diameter machine, weighing 2,000 tons and composed of 288 C-shaped magnets (right) that guided the protons in a circular path. After one second of acceleration in the Cosmotron, the protons had traveled 135,000 miles and had reached an energy of about 3 GeV. At that energy, the protons were allowed to strike a target. The fragments of the nuclear collisions were observed in photographs of the telltale trails they left in cloud chambers, or with other detectors.

These observations proved to be tremendously important for a better understanding of the complex nature of many subatomic particles. In fact, the Cosmotron was the first machine to produce all the types of negative and positive mesons known to exist in cosmic rays, making possible the discoveries of the K⁰_L meson and the first vector meson. It was also the first accelerator to produce heavy unstable particles, some of which were formerly called "V" particles, and this led directly to the experimental confirmation of the theory of associated production of strange particles. 

After fourteen years of service to the physics research community, the Cosmotron ceased operation in 1966 and was dismantled in 1969. Though state of the art when built, this accelerator had inherent design limitations that restricted the energies that it could achieve.  Knowledge gained from the Cosmotron would lead to revolutionary design improvements that would overcome these limitations and pave the way for construction of Brookhaven's next big accelerator: the Alternating Gradient Synchrotron. 

One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.

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