The dense z-pinch is considered as the basis for a compact and relatively simple fusion reactor. The pinch is created in a 200 µm diameter vortex of heavy water formed on the axis of a cylindrical pressure vessel of approximately one meter in radius. The water is the electrical insulator, the heat transfer medium, and acts as a continuously replaceable first wall. The pinch is pulsed repetitively at 120 Hz and with an input power of 17 MWe would produce about 500 MWth. The concept makes considerable use of existing pressurized water fission reactor technology. Experiments underway to test the plasma physics aspect of this concept have demonstrated that a pinch carrying 330 kA can be formed in quartz capillaries of diameters between 200–1600 µm which are filled with deuterium at pressures ranging from 80 mm to 20 atmospheres.