The Tevatron is a particle accelerator at the Fermi National Accelerator Laboratory (Fermilab) in Batavia, Illinois, United States. It was built from 1983 to 1989, and began operation in 1985. Its name comes from its original energy goal of 10 TeV (teraelectronvolts); it now operates at an energy of up to 9 GeV (gigaelectronvolts). The main ring of the accelerator is 6.28 km (3.90 mi) in circumference, with two side rings each 1.024 km (0.639 mi) long. The design of the Rings used for the Collider Detector Facility and other experiments on the Tevatron are very similar to those on CERN’s Large Hadron Collider; this similarity helped physicists move quickly to use the LHC when it was completed because they were already familiar with how such machines worked.
The American Physical Society selected the discovery of the top quark as “Outstanding Scientific Achievement” for 1995. In addition, five Nobel Prizes have been awarded for work conducted using data from Fermilab’s accelerators and detectors: Leon M. Lederman and Melvin Schwartz shared half of the 1988 prize in physics for their discovery that neutrinos come in more than one type; Samuel Ting shared the 1976 prize in physics for his discovery of a new subatomic particle called the J/psi meson; Burton Richter shared half of that same prize for his independent discovery days later also using data from Fermilab’s accelerator complex; Val Logsdon Fitch and James Cronin shared half of the 1980 prize in physics for their experimental demonstration that time-reversal invariance is not always valid. Sophia Drell was a co-recipient of this latter prize as well as being named Outstanding Junior Investigator by APS in 1977.
Tevatron collisions have also been important outside particle physics. In 2010, scientists working on MINOS reported results which indicated that muon neutrinos can change into electron neutrinos while travelling through space – something not predicted by current Standard Model theories. This finding could help explain why more matter than antimatter seemed to be created after the Big Bang,:p290 although followup studies have found conflicting results about whether this effect occurs or not.:p30 Another experiment at Tevatron announced results which showed evidence consistent with pentaquarks – particles made up of five quarks rather than just three – although again followup studies were inconclusive about whether these particles really exist or not.:pp79–80:p111 Nevertheless, even if they do turn out not to exist after all, researchers believe that understanding why so many different kinds appear to be seen in initial observations could still teach us something important about how quarks interact with each other.:p32
Work continues at Fermilab even though operation of its accelerators has ceased. Scientists are still analyzing data collected by CDF and DZero during their years of operation, and there are plans to upgrade some parts of the facility so it can continue making contributions to science even without accelerating particles itself. For example, one proposal would see protons sent down one arm of a future Long Baseline Neutrino Facility while electrons are sent down another arm: these beams would then pass through different sections of former Tevatron tunnels before reaching faraway detectors where any differences between neutrinos and antineutrinos produced could be studied. Other ideas involve reusing components such as magnets or RF cavities elsewhere,:pp43–44 or sending beams into existing dark matter detection facilities located inside old mining tunnels under Wilson Hall so they can search for hypothetical weakly interacting massive particles (WIMPs).