Abstract: The present invention relates to a resonant vacuum arc discharge apparatus for producing nuclear fusion. A resonant high-frequency high-voltage alternating current (AC) power supply is used to efficiently power a fusion tube normally containing deuterium, tritium and/or helium-3 vapor. Metals that can hold large amounts of hydrogen isotopes such as palladium and titanium can be used to increase the target density. The nuclear fusion device can be used for energy production, well logging, uranium mining, neutron activation analysis, isotope production or other applications that require a neutron source.