Abstract: A method and apparatus for controlling cavitation to form a high pressure zone and/or jets of material is provided by the present invention. A unstable, superheated phase bubble is created by applying a voltage pulse to a firing resistor in a reaction chamber and imploded to produce a high pressure region. The reaction chamber has sloped edges that focus opposing shock waves created by the imploding phase bubble toward a high pressure reacting region. The liquid is filled with deuterium, tritium, uranium, unstable isotopes, and/or other materials that are susceptible to nuclear or chemical reactions at high pressures. The resulting reactions can be used for countless applications.