Intersecting Storage Rings
The Intersecting Storage Rings (ISR ) were two opposing proton storage rings with about 300m diameter at CERN.
History
In 1956, drew up a group at the Midwestern Universities Research Association ( MURA ) proposals, as collected bunches in storage rings by Stacking Beam, and could then be brought into collision. The collision of particles of opposite direction can be the supplied energy use far better than hitting a static target, where a significant part of the energy due to the momentum conservation law in the mean kinetic energy of the fragments is lost.
After commissioning of the 28 GeV Proton Synchrotron (PS ) at CERN in 1959, the MURA - proposals were received and further elaborated, since the effective usable energy of PS was increased from 7 GeV to 56 GeV in this way. To test the MURA - concept, a storage ring for electrons CESAR was built. In 1964, a proposal for the construction of the ISR was filed and granted in the following year, France introduced an adjacent to the CERN site area of about 40 acres available on the began construction in January 1966.
The first ring was taken in October 1970 for test purposes in operation, the second ring followed in January 1971. The official inauguration and commissioning of the ISR took place in October 1971.
At the ISR extensive experience in the operation of the conflict of storage rings was collected, this experience was used to perform in 1979 at the Super Proton Synchrotron (SPS ) collision experiments between protons and antiprotons.
In June 1984, the operation has been set, the staff moved to the Large Electron-Positron Collider.
Technology
The two rings had a diameter of 300 m, an opening cross section of 160 x 52 mm and were located in a 15 m wide tunnel. Between the two rings there were eight crossing points at which packages could be particles collide. The ISR were located about 200 meters from the PS and were to be filled with protons through a tunnel per each direction connected to the PS. The acceleration of protons was made in PS, but the protons in the ISR could be post-accelerated up to 31.4 GeV.
In order to achieve sufficient luminosity, the number of particles per particle bunch with respect to the number of particles delivered by the PS Beam Stacking means had to be considerably increased. Were collected up to 400 hp provided by the packages on a 60-70 mm wide and 3-10 mm high orbit, and there are typically 11 hours, even stored in a single case, 345 hours long.
In particular, the high beam currents of several amperes and the long residence time of the beam placed new demands on the magnetic systems and the vacuum quality of the steel tubes.
During operation, the evacuated beam tube was repeatedly hit by a runaway proton beam and perforated.