Fermilab's Accelerator Complex


Fermilab's accelerator complex comprises seven particle accelerators and storage rings. It produces the world's most powerful, high-energy neutrino beam and provides proton beams for various experiments and R&D programs.

Fermilab's accelerator complex delivers high-intensity neutrino beams and provides optimal beam for a broad range of new and existing experiments, including the Long-Baseline Neutrino Experiment, Muon g-2 and Mu2e.

Fermilab's accelerators and how they fit into the laboratory's accelerator complex are described below.


Radio-frequency quadrupole

The radio-frequency quadrupole accelerator, or RFQ, is the starting point for Fermilab's chain of accelerators, providing the particle beam source for the entire accelerator complex. The 11-foot-long accelerator takes low-energy proton beam from an ion source, accelerates and "bunches" it into separate packets of particles, and injects it into Fermilab's linear accelerator, or Linac. The RFQ accelerates beam from 35 keV to 750 keV.



Fermilab's linear accelerator, better known as the Linac, is a roughly 500-foot straight accelerator that brings proton beams up to energies of about 400 MeV, providing proton beam for the Booster accelerator and the rest of the chain of accelerators. The Linac provides proton beam for the MuCool test area, which is used to develop accelerator components for a future muon collider.



Proton beams enter the Fermilab Booster from the Linac, accelerating through its approximately 1,500-foot-circumference ring to an energy of 8 GeV. The Booster will provide low-energy neutrino beam for the MicroBooNE experiment, as well as the Muon g-2 and Mu2e experiments. It also provides beam to the Recycler.



The Recycler is a kind of staging area for proton beams after they exit the Booster. Once beam enters the Recycler, a 2-mile-circumference ring, it is "slip stacked" – combined into batches of protons to form a more intense beam. Once that is done, the proton beam enters the Main Injector, on top of which the Recycler sits.


Main Injector

The Main Injector, situated directly beneath the Recycler in the same tunnel and two miles around, ramps up proton beam from the Recycler from 8 GeV to 120 GeV.

The world's highest-intensity neutrino beams are generated from these proton beams. The Main Injector thus provides neutrino beams for MINOS, MINERvA and NOvA experiments, as well as the future Long-Baseline Neutrino Experiment. The Main Injector proton beam will also provide beams of particles called muons for Fermilab's Muon g-2 and Mu2e experiments. It also delivers beam to the SeaQuest fixed-target experiment and to a dedicated facility for testing of detector technologies.


Muon Delivery Ring

Some of the proton beam from the Booster will be used to produce pions in a specially designed target system. For the Muon g-2 and Mu2e experiments, these pions will then decay into particles called muons. These muons circulate through the 144-foot-circumference Muon Delivery Ring. The Muon Delivery Ring delivers these muons into a muon storage ring for further study.


Advanced Superconducting Test Accelerator

The Advanced Superconducting Test Accelerator is a superconducting linear accelerator based on the technology developed for the International Linear Collider. If fully built out, it would accelerate beams of electrons to nearly 1 GeV. ASTA also will contain a circular test accelerator, called IOTA, to explore brand-new ways of focusing and transporting particle beams. Housed in Fermilab's NML building and separately from the accelerator complex, ASTA gives scientists the opportunity to explore new ways of generating, accelerating and manipulating particle beams, making use of the power of superconducting radio-frequency acceleration technology, which is the technology of choice for future high-energy accelerators.