G21HOBTAINING ENERGY FROM RADIOACTIVE SOURCESAPPLICATIONS OF RADIATION FROM RADIOACTIVE SOURCES, NOT OTHERWISE PROVIDED FORUTILISING COSMIC RADIATION measurement of nuclear or X-radiation G01T; fusion reactors G21B; nuclear reactors G21C; lamps in which a gas filling is excited to luminescence by external corpuscular radiation or by radioactive material structurally associated with the lamp H01J65/04, H01J65/06In this subclass non-limiting references (in the sense of paragraph 39 of the Guide to the IPC) may still be displayed in the scheme. G21H1/00 G21H1/00Arrangements for obtaining electrical energy from radioactive sources, e.g. from radioactive isotopes , nuclear or atomic batteries G21H1/02Cells charged directly by beta radiation G21H1/04Cells using secondary emission induced by alpha radiation, beta radiation, or gamma radiation G21H1/06Cells wherein radiation is applied to the junction of different semiconductor materials G21H1/08Cells in which radiation ionises a gas in the presence of a junction of two dissimilar metals, i.e. contact potential difference cells G21H1/10Cells in which radiation heats a thermoelectric junction or a thermionic converter G21H1/103Cells provided with thermo-electric generators G21H1/106Cells provided with thermionic generators G21H1/12Cells using conversion of the radiation into light combined with subsequent photoelectric conversion into electric energy G21H3/00Arrangements for direct conversion of radiation energy from radioactive sources into forms of energy other than electric energy, e.g. into light or mechanic energy G21H3/02in which material is excited to luminesce by the radiation lamps in which a gas filling or screen or coating is excited to luminesce by radioactive material structurally associated with the lamp  H01J65/00 G21H5/00Applications of radiation from radioactive sources or arrangements therefor, not otherwise provided for  G21H5/02as tracers G21H7/00Use of effects of cosmic radiation