The FNAL injector upgrade
  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. 
C. Y. Tan, D. S. Bollinger, K. L. Duel, J. R. Lackey, W. A. Pellico   (Fermilab)
physics.acc-ph