Physics for the New Millennium:

The Main Injector Raises the Stakes for Fermilabís Accelerators

1.Linac Beam: The Linear Accelerator takes hydrogen ions from the Preaccelerator at 750,000 electron volts (eV), and accelerates them to 400 million electron volts (MeV).

2.Protons to Booster: At the Booster, the hydrogen ions are stripped of their electrons. The remaining protons are then accelerated from 400 MeV to 8 GeV (billion electron volts).

3.Protons to Main Injector: The Main Injector provides high-intensity proton beams for antiproton production; combines proton bunches from the Booster into a single high-intensity bunch for collider operations; accelerates antiprotons to inject into the Tevatron; decelerates antiprotons from the Tevatron, sending them to the Recycler; and sends protons to the NuMI experiment for neutrino production. The Main Injector accelerates protons from 8 GeV to 120 GeV for antiproton production, and to 150 GeV for the Tevatron. Particles circle the Main Injectorís two-mile circumference nearly 100,000 times per second.

4.Protons to Tevatron: The Main Injector sends protons and antiprotons to the Tevatron. The Tevatronís 1,000 superconducting magnets operate at the temperature of liquid helium (-450° F). Protons and antiprotons collide at CDF and DZEROñ5,000-ton detectors that track the results of the collisions. Particles circle the Tevatronís four-mile circumference nearly 50,000 times per second.

5.800 GeV Beam to Switchyard: In the fixed target mode, the 800 GeV beam is extracted from the Tevatron and relayed via the switchyard to fixed target experiments.

6.120 GeV Beam to Switchyard: The Main Injector allows fixed-target experiments to proceed simultaneously with colliding-beam experiments, with a 120 GeV proton beam.

7.Recycler Storage: The worldís largest use of permanent magnet technology, the Recycler shares the tunnel with the Main Injector, recovering and recycling antiprotons from the Tevatron. Permanent magnets do not need power or cooling water. The Recycler will provide more antiprotons for the Tevatron, for a tenfold increase in collisions. More collisions mean more possibilities for discovery.

8.Recycler to Main Injector and Tevatron: The Recycler recovers and stores antiprotons that would have been discarded. The recycled antiprotons are transferred to the Main Injector, and accelerated for use in further Tevatron collider experiments.