Bevatron Operation and Development, VII - August, Septemper,October 1955

摘要

The major physics research effort this quarter was directed toward the detection of the antiproton. Negative particles of proton mass were first counted on September 22, 1955. On October 19, 1955 the discovery and identification of the antiproton was announced. Total cross-section measurements for {pi}{sup +} and {pi}{sup -} mesons continued. A study was made of neutron interactions and of the {gamma}-ray decay products of mesons. Proton-proton scattering was done at 2 Bev and 4 Bev using counters, and at 5.5 Bev using a 35-atmos diffusion cloud chamber. Emulsion exposure s to protons were made for three groups outside the laboratory. The bevatron facilities were improved this quarter by the addition of a heavy-duty inner-radius platform at the experimental area. New thin windows, an improved plunging beam clipper, a new 4-in. quadrupole-magnet set, and a new 12-by-60-in. analyzing magnet were added to the experimental facilities. Improvements were made in magnet-current stabilization and in reliability of the radiofrequency-accelerating systems. The beam was successfully tracked during a step in peak magnet current, and for a short time into inversion.