Alternating Gradient Synchrotron

The Alternating Gradient Synchrotron (abbreviation: AGS ) is a synchrotron particle accelerator with 800 m circumference at the Brookhaven National Laboratory ( BNL ).

History

After the construction of Cosmotrons began on BNL plans to build a stronger successor, which, however, showed difficulties. During the cross-section of current ring during cosmotron already had dimensions of about 20x60 cm, 50x150 cm as would have been necessary to the successor. Very large weight of the electromagnets and corresponding costs would have been the consequence. A way out was a concept by Courant, Livingston and Snyder, to focus the circulating particles by means of an alternating magnetic field closely, the so-called "strong focusing ", whereby the rotary ring could shrink to about 5 cm cross-section. For the first time this principle has been tested with the construction of a 1.3 GeV electron synchrotron in 1954 at BNL.

Almost at the same time took place the plans for the construction of the proton synchrotron (PS ) at CERN. There the principle of strong focusing was taken so that emerged with the AGS and the PS two very similar machines. The PS went into operation in November 1959 and the AGS was followed a few months later.

On July 29, 1960, the AGS reached the planned proton energy of 33 GeV, thus replacing the proton synchrotron as the world's most powerful particle from.

In 2000 went on the BNL Relativistic Heavy Ion Collider ( RHIC ) in operation since the AGS serves as a pre-accelerator.

Operation

In the AGS heavy ion such as gold and iron, in addition to protons accelerated. Since 1984 polarized protons can be produced up to an energy of 16.5 GeV with the AGS.

When operating as a pre-accelerator RHIC, the AGS is only in relatively short periods of a few minutes, which are about eight to ten hours apart, are used. In the remaining time the AGS is available for further purposes.