LBNL Image Library -- Collection BERKELEY-LAB/ACCELERATORS/184-INCH-CYCLOTRON

Charter Hill at groundbreaking for 184-inch cyclotron in 1944

Image File

97502211

Title

Charter Hill at groundbreaking for 184-inch cyclotron in 1944

Description

"Charter Hill" as it looked when ground was broken for the 184-inch cyclotron in August, 1940. 184-inch cyclotron background: In 1939, not long after his invention of the cyclotron, Lawrence announced plans for a large-scale (originally 100 MeV) cyclotron. With the onset of World War II, the project became a wartime priority. TheRockefeller Foundation pledged the principal amount, $1.4 million, in April 1940. It was to buy a cyclotron with a magnet face 184 inches in diameter. The machine would open the frontier beyond 100 MeV, where there lurked 'discoveries of a totally unexpected character and of tremendous importance.' But wartime uses intervened. The magnet was adapted for use in a 'Calutron,' a huge mass spectrograph to test the feasibility of Lawrence's plan to separate the fissile, or explosive, part of natural uranium, U-235, from its much more plentiful companion isotope, U-238. This work led to the establishment of large-scale calutron facilities at Oak Ridge. After the war, the 184-inch cyclotron was completed as a synchrocyclotron, or synchrotron, incorporating the principle of phase stability developed by Edwin McMillan and Vladimir Veksler. It became a valuable instrument for physics and, later, for biological and medical research. Its most important achievements include: the first production and identification of a subnuclear particle (the charged pi meson, or pion) at an accelerator; studies of the interaction and properties of pions; studies of proton-proton and neutron-proton interactions; and use of heavy particles for medical therapy. It ended operation in the 1980s, and the domed structure that housed the cyclotron was adapted to house the Berkeley National Advanced Light Source. -- JG

Citation Caption

Magnet, Vol.15, Nos.10-11, October-November 1971, p. 2

Date

1944

TEID Doc ID

XBD9705-02211.TIF