  The present FNAL H- injector has been operational since the 1970s and
consists of two magnetron H- sources and two 750 keV Cockcroft-Walton
Accelerators. In the upgrade, both slit-type magnetron sources will be replaced
with circular aperture sources, and the Cockcroft-Waltons with a 200 MHz RFQ
(radio frequency quadrupole). Operational experience at BNL (Brookhaven
National Laboratory) has shown that the upgraded source and RFQ will be more
reliable, improve beam quality and require less manpower than the present
system.

Accelerator Physics