The Bevatron

I might just mention that Luis Alvarez also invented and built a linear accelerator for 32 MeV protons, and this is the scribbling on their blackboard when they first got a beam in 1947.
Search for the first beam from the proton linear accelerator (10/16/47). Alvarez's 8:30 p.m. blackboard calculation 'proving' that geometry must be changed and that the "machine would not work", with an added note that at 2:40 a.m., six hours later, they achieved the beam.
Then Lawrence went on to build the Bevatron. That's the huge machine, to produce 6 BeV protons, 150 feet across, or something like that. Here is the building in which it was housed. It's still there.
Overall view of Bevatron. Lawrence Radiation Laboratory (LRL) from Indian Rock Drive. Visible in this picture are: Building 70, Building 51, the Bevatron, Administration Building.

It was used for a number of things, but one was the discovery of the antiproton by Clyde Wiegand and Tom Ypsilantis and Emilio Segrè, and Owen Chamberlain, who was away at the time the picture was taken.

Surrounding Edward Lofgren (center) are discoverers of the anti-proton, (left to right) Emilio Segrè, Clyde Wiegand, Owen Chamberlain and Thomas Ypsilantis. Seaborg, Weigand, Segrè, Steiner, McMillan Nobel Prize celebration.
The Bevatron began to operate in 1954 and the antiproton was discovered in 1955, for which Segrè and Chamberlain were awarded the Nobel Prize in 1959. Here's Ed McMillan, the director of the Lab. I think it's unfortunate that Clyde Wiegand also wasn't involved as a recipient of the Nobel Prize.