Abstract: This invention combines minor, but not obvious, adaptations of available and, for this field, relatively simple hardware that primarily uses the least power-hungry electrostatic (rather than mainly magnetic) control of accelerated colliding beams of bare deuterium nuclei in three-dimensionally pre-determined collision attitudes that are now found by new research to offer a method (with required apparatus) of fusing directly to helium four with high efficiency release of the greatest possible single-step free energy of fusion in kinetic energy of helium four charged nuclei and with minimized side-effects (if any) of wasted energy and troublesome output products in neutrons, radiation, helium three or tritium nuclei, and plasma electrons. This invention can be combined with the most efficient prior art in deuterium ion sources, continued fusion processes, output power conversion, and full reactor assembly at any scale from laboratory experiments to industrial power networks.