Cosmotron

The cosmotron was a synchrotron particle accelerator of 23 m in diameter at the Brookhaven National Laboratory.

History

In April 1948, the U.S. Atomic Energy Commission AEC approved a plan to build a proton synchrotron with a hitherto unattained proton energy of about 3 GeV. Particles of this velocity were known hitherto only from cosmic radiation, hence the name cosmotron.

In May 1952, a proton energy of 1 GeV, and reaches the planned energy of 3.3 GeV in January 1953.

With the cosmotron the hitherto known from cosmic rays charged mesons, as well as the so-called V- particles could be generated. The research on many phenomena has been greatly simplified so that substantial insights have been possible in the internal structure of the nucleons.

After commissioning of the much more powerful alternating gradient synchrotron in July 1960, the cosmotron slowly lost its usefulness and was shut down in 1966 and finally scrapped in 1969.

Technology

The cosmotron weighed about 1800 tons and consisted of 288 electromagnet with C-shaped iron cores whose gap opening about 20 cm high and 60 cm deep was. The magnets were arranged in ring - symmetrically in four segments, so that there was a magnetic field gradient with annular symmetry within the evacuated circular ring. The circulating protons were focussed solely by this field gradient on the predefined trajectory, to which, however, a large annular chamber and therefore large magnets were needed. In the accelerators of the next generation, the Alternating Gradient Synchrotron at BNL and the Proton Synchrotron at CERN, the focus has been greatly refined by a method of changing the field gradient along the direction of flight, so that there are annular chambers and magnets with significantly smaller cross sections of about 5 cm for use could.

A new feature on cosmotron was that the accelerated particles could be ejected radially from the circular ring to the experiments, earlier experiments had to be installed in the accelerator itself.