A device for producing electricity. The device comprises a source of tritium radioisotopes, an element Th maintained at a temperature Th, and an element Tc maintained at a temperature Tc; Tc lower than Th. The source generates heat and is disposed in thermal communication with the element Th to maintain the temperature Th. First and second doped elements, each doped with a different dopant type, are oriented in parallel relative to the heat flow path between the element Th and the element Tc and electrically connected in series According to the Seebeck effect, a voltage is generated between the first and second doped elements due to a temperature differential between the Tc and Th, causing current to flow through the serially-connected doped elements. Helium generated during generation of the radioisotopes is vented from the device.

.sup.210Pb and .sup.227Ac are used in thermal energy production as precursor isotopes, which have been isolated and are allowed to age to the point of secular equilibrium with their progeny, referring to the decay product isotopes in the radioactive decay chain of each. Both .sup.210Pb and .sup.227Ac are in the radioactive decay chains of naturally occurring uranium isotopes, and are each subject to their own natural radioactive decay. While not particularly energetic through their own decay, they (1) are separable from their parent isotopes or may be created in a reactor, (2) have half-lives of around 22 years, and (3) are precursors (natural radioactive decay parents) to subsequent rapid and energetic decay processes. These two isotopes can offer significant advantages as RPS fuel compared to the currently used .sup.238Pu.

A thermionic energy conversion system, preferably including one or more electron collectors, interfacial layers, encapsulation, and/or electron emitters. A method for manufacturing the thermionic energy conversion system. A method of operation for a thermionic energy conversion system, preferably including receiving power, emitting electrons, and receiving the emitted electrons, and optionally including convectively transferring heat.

A modified Nuclear Thermionic Avalanche Cell (NTAC) to reduce back-scatter losses of avalanche electrons emitted by a NTAC. The present invention provides a novel topological surface configuration for electron collector layers in NTAC devices. Sawtooth configurations of the surface configurations of electron collector layers allow for the recapture of back-scattered electrons, increasing the efficiency of NTAC devices as well as reducing thermal loading and increasing NTAC efficiency.

A power generator system includes one or more heat transfer members configured to contact: a heat source in a hazardous waste repository of a directional drillhole that stores nuclear waste in one or more nuclear waste canisters, and a heat sink in the hazardous waste repository; and one or more thermoelectric generators thermally coupled to the one or more heat transfer members and configured to generate electric power based on a temperature difference between the heat source and the heat sink.

A generator (100) of the present invention has a heat source (101) containing a radioisotope substance precursor that becomes a radioisotope substance by irradiation with a neutron and a controller (108) that controls the irradiation with the neutron.

Systems, methods, and devices of the various embodiments enable a Nuclear Thermionic Avalanche Cell (NTAC) to capture gamma ray photons emitted during a fission process, such as a fission process of Uranium-235 (U-235), and to breed and use a new gamma ray source to increase an overall emission flux of gamma ray photons. Various embodiments combine a fission process with the production of Co-60, thereby boosting the output flux of gamma ray photons for use by a NTAC in generating power. Various embodiments combine a fission process with the production of Co-60, a NTAC generating avalanche cell power, and a thermoelectric generator generating thermoelectric power.

Systems, methods, and devices of the various embodiments may provide a portable power system for powering small devices that may be small, may be compact, may provide continuous power, and may be lightweight enough for an astronaut to carry. Various embodiments may provide a compact, thermionic-based cell that provides increased energy density and that more efficiently uses a heat source, such as a Pu-238 heat source. Nanometer scale emitters, spaced tightly together, in various embodiments convert a larger amount of heat into usable electricity than in current thermoelectric technology. The emitters of the various embodiments may be formed from various materials, such as copper (Cu), silicon (Si), silicon-germanium (SiGe), and lanthanides. Various embodiments may be added to regenerative thermionic cells with multiple layers to enhance the energy conversion efficiency of the regenerative thermionic cells.

A triboluminescence isotope battery can include a housing defining a chamber, and one or more energy conversion devices. Each energy conversion device can include a holder, a cantilever beam, a triboluminescence component, a first photoelectric conversion component, a radioactive source, a first charge collecting component, a second charge collecting, a first thermoelectric conversion component, and a heat dissipation component.

A triboluminescence isotope battery can include a housing defining a chamber, and one or more energy conversion devices. Each energy conversion device can include a holder, a cantilever beam, a triboluminescence component, a first photoelectric conversion component, a radioactive source, a first charge collecting component, a second charge collecting, a first thermoelectric conversion component, and a heat dissipation component.