Abstract: Discrete, contained charged particle bundles are converted into heat energy for driving a load. In one embodiment the bundles propagate between a cathode and anode in a gap between a pair of solid dielectric members, which gap has a dimension between a pair of facing surfaces of the dielectric members equal approximately to the diameter of a group of such bundles propagating together. The bundles are derived in response to high voltage short duration pulses derived from a modified Blumlein switch. The bundles are periodically derived and converted to current that flows in a circuit having a resonant frequency equal to the frequency of the bundles. In another embodiment the bundles are derived from a cathode including a liquid metal pool in contact with a solid dielectric surface along which the bundles propagate to an x-ray emitting target or an anode that is heated by the bundles, to convert the x-rays into useful emission and/or the heat into useful work.