ISABELLE
From Wikipedia, the free encyclopedia
ISABELLE (also known later as Colliding Beam Accelerator, CBA) was a 200+200 GeV proton–proton colliding beam particle accelerator partially built by the United States government at Brookhaven National Laboratory in Upton, New York, before it was cancelled in July, 1983.
A colliding beam, storage ring accelerator was first proposed by Gerard O'Neill of Princeton in 1956, who built an electron-electron system beginning in 1957 (operational in 1962, first collisions in 1964) with assistance from Burton Richter, William C. Barber and Bernard Gittelman.[1] The AdA accelerator, an electron-positron system, stored its first beam in 1961 at Frascati National Laboratories, Italy and was later moved to Orsay Laboratory, France, where in 1964 it recorded first e+e− collisions.[2] At the same time, two colliding-beam experiments were conceived and built by Budker and his group at the Institute of Nuclear Physics in Novosibirsk, Russia, Soviet Union: electron-electron VEP-1 (first collisions in 1964) and electron-positron VEPP-2 (first collisions in 1965).
The idea of using alternating gradient synchrotron (AGS) technology [3] to build storage rings for a proton-proton colliding beam accelerator was considered at a summer study held at Brookhaven in 1963.[4] The Intersecting Storage Rings (ISR) facility at CERN, a 30+30 GeV proton-proton system, opened in 1971 and became the first high energy hadron collider. The SPEAR collider at the Stanford Linear Accelerator Center, a 3+3 GeV electron-positron system, was completed in 1972 and soon contributed to discoveries of the ψ meson and τ lepton, both recognized in Nobel Prizes. The ψ had previously been found in a fixed-target experiment at the Brookhaven AGS, where it was called the J, but it was better measured with SPEAR.