LBNL Image Library -- Collection BERKELEY-LAB/ACCELERATORS/BEVATRON

Ed McMillan and Edward Lofgren posed on shielding blocks as Bevatron goes back on job

Image File

97502170

Title

Ed McMillan and Edward Lofgren posed on shielding blocks as Bevatron goes back on job

Description

Wide-angle view of the remodeled Bevatron shows extensive new shielding, including seven-foot- thick concrete roof and "igloo" at hub. Taking in the view from the top are Lawrence Radiation Laboratory Director Edwin McMillan (l.) and Bevatron Group Leader Edwin Lofgren. In this, its first major modification program, the Bevatron got a new injection system, the addition of an external proton beam, increased shielding, movable targets, and a new control system. The Bevatron first went into operation in 1954. At that time, it was the largest, most powerful accelerator in the world. The modification program described here was one of many that would keep the machine working at the forefront of physics for the next forty years. The Bevatron played the leading role in three of the most important discoveries of particle physics: experimental studies of "strange" particles leading to the discovery of parity nonconservation (the first known example of a lack of symmetry in nature); the discovery of nuclear antimatter (the antiprotons and the antineutron); and the discovery of the "resonances" -- the particle explosion of the 1960's that led to the development of the quark model and the current understanding of the basic nature of matter. In the 1970s, the Bevatron seemed to be nearing the end of its useful career in high-energy physics, and there was talk of shutting it down. Nevertheless, it was given a productive new lease on life through the invention of the Bevalac, in which the Bevatron was linked to the SuperHILAC linear accelerator. Nuclei begin their journey in the SuperHILAC and then were passed through a transfer line to the Bevatron, where they were accelerated almost to the speed of light. With the later addition of an improved vacuum system and other modifications, the Bevalac became the only machine the world capable of accelerating all of the elements of the periodic table to relativistic energies. The Bevatron/Bevalac finally ceased operations on February 21, 1993. - JG

Citation Caption

Magnet, Vol. 7, No. 2, February 1963, p. 4

Date

1963

People

Ed McMillan and Edward Lofgren

TEID Doc ID

XBD9705-02170.TIF