Intersecting Storage Rings

The ISR (standing for "Intersecting Storage Rings") was a particle accelerator at CERN. It was the world's first hadron collider, and ran from 1971 to 1984, with a maximum center of mass energy of 62 GeV. From its initial startup, the collider itself had the capability to produce particles like the J/ψ and the upsilon, as well as observable jet structure; however, the particle detector experiments were not configured to observe events with large momentum transverse to the beamline, leaving these discoveries to be made at other experiments in the mid-1970s. Nevertheless, the construction of the ISR involved many advances in accelerator physics, including the first use of stochastic cooling, and it held the record for luminosity at a hadron collider until surpassed by the Tevatron in 2004.

Hadron colliders

Some of the buildings associated with the ISR at CERN, Geneva. The accelerator itself is beneath the curved, tree-covered hill that runs around the outside of the road.
Intersecting Storage Rings	CERN, 1971–1984
Proton-Antiproton Collider (SPS)	CERN, 1981–1991
ISABELLE	BNL, cancelled in 1983
Tevatron	Fermilab, 1987–2011
Superconducting Super Collider	Cancelled in 1993
Relativistic Heavy Ion Collider	BNL, 2000–present
Large Hadron Collider	CERN, 2009–present
Future Circular Collider	Proposed

Intersecting Storage Rings

See also

• Timeline of particle discoveries

External links

• ISR startup
• Early history of the ISR
• Picture of the ISR from above - It's the large earthen ring with circular roads inside and outside.