Induction barrier rf and applications in main injector

Two induction barrier rf systems have been designed and fabricated at Fermilab and installed in the Main Injector. They use the nanocrystal magnetic alloy called Finemet for the cavities and high voltage fast MOSFET switches for the modulators. Each system delivers ±10 kV square pulses at 90 kHz. They have been used for adiabatic beam stacking (beam compression), machine acceptance measurement and gap cleaning in the injection area for magnet protection, and will be tested for fast beam stacking for doubling the proton flux on the NuMI production target. The systems work reliably and cost much less than a resistive barrier rf system. Comparison with a similar system built at KEK reveals many similarities and also some important differences. This work is partially funded by the US-Japan collaborative agreement. (author)