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Nuclear Lightbulb
300px, Nuclear gas core closed cycle rocket engine diagram, nuclear "light bulb" A nuclear lightbulb is a hypothetical type of spacecraft engine using a gaseous fission reactor to achieve nuclear propulsion. Specifically it would be a type of gas core reactor rocket that uses a quartz wall to separate nuclear fuel from coolant/ propellant. It would be operated at temperatures of up to 22,000°C where the vast majority of the electromagnetic emissions would be in the hard ultraviolet range. Fused silica is almost completely transparent to this light, so it would be used to contain the uranium hexafluoride and allow the light to heat reaction mass in a rocket or to generate electricity using a heat engine or photovoltaics. This type of reactor shows great promise in both of these roles. Rocket engine As a rocket engine it, like all nuclear rocket designs, can greatly exceed the exhaust speed and specific impulse of a chemical rocket. However, it also does not involve the release o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gas Core Light Bulb
Gas is one of the four fundamental states of matter (the others being solid, liquid, and plasma). A pure gas may be made up of individual atoms (e.g. a noble gas like neon), elemental molecules made from one type of atom (e.g. oxygen), or compound molecules made from a variety of atoms (e.g. carbon dioxide). A gas mixture, such as air, contains a variety of pure gases. What distinguishes a gas from liquids and solids is the vast separation of the individual gas particles. This separation usually makes a colourless gas invisible to the human observer. The gaseous state of matter occurs between the liquid and plasma states, the latter of which provides the upper temperature boundary for gases. Bounding the lower end of the temperature scale lie degenerative quantum gases which are gaining increasing attention. High-density atomic gases super-cooled to very low temperatures are classified by their statistical behavior as either Bose gases or Fermi gases. For a comprehensive listi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reaction Mass
Working mass, also referred to as reaction mass, is a mass against which a system operates in order to produce acceleration. In the case of a chemical rocket, for example, the reaction mass is the Product (chemistry), product of the burned fuel shot backwards to provide propulsion. All acceleration requires an exchange of momentum, which can be thought of as the "unit of movement". Momentum is related to mass and velocity, as given by the formula ''P = mv,'' where ''P'' is the momentum, ''m'' the mass, and ''v'' the velocity. The velocity of a body is easily changeable, but in most cases the mass is not, which makes it important. Rockets and rocket-like reaction engines In rockets, the total velocity change can be calculated (using the Tsiolkovsky rocket equation) as follows: \Delta\,v = u\,\ln\left(\frac\right) Where: * ''v'' = ship velocity. * ''u'' = exhaust velocity. * ''M'' = ship mass, not including the working mass. * ''m'' = total mass ejected from the ship (working mass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Reactors
A nuclear reactor is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions. Nuclear reactors are used at nuclear power plants for electricity generation and in nuclear marine propulsion. Heat from nuclear fission is passed to a working fluid (water or gas), which in turn runs through steam turbines. These either drive a ship's propellers or turn electrical generators' shafts. Nuclear generated steam in principle can be used for industrial process heat or for district heating. Some reactors are used to produce isotopes for medical and industrial use, or for production of weapons-grade plutonium. , the International Atomic Energy Agency reports there are 422 nuclear power reactors and 223 nuclear research reactors in operation around the world. In the early era of nuclear reactors (1940s), a reactor was known as a nuclear pile or atomic pile (so-called because the graphite moderator blocks of the first reactor were placed into a tall pi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gibbs Free Energy
In thermodynamics, the Gibbs free energy (or Gibbs energy; symbol G) is a thermodynamic potential that can be used to calculate the maximum amount of work that may be performed by a thermodynamically closed system at constant temperature and pressure. It also provides a necessary condition for processes such as chemical reactions that may occur under these conditions. The Gibbs free energy change , measured in joules in SI) is the ''maximum'' amount of non-expansion work that can be extracted from a closed system (one that can exchange heat and work with its surroundings, but not matter) at fixed temperature and pressure. This maximum can be attained only in a completely reversible process. When a system transforms reversibly from an initial state to a final state under these conditions, the decrease in Gibbs free energy equals the work done by the system to its surroundings, minus the work of the pressure forces. The Gibbs energy is the thermodynamic potential that is minim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Project Orion (nuclear Propulsion)
Project Orion was a study conducted between the 1950s and 1960s by the United States Air Force, DARPA, and NASA for the purpose of identifying the efficacy of a starship directly propelled by a series of explosions of atomic bombs behind the craft—nuclear pulse propulsion. Early versions of this vehicle were proposed to take off from the ground; later versions were presented for use only in space. Six non-nuclear tests were conducted using models. The project was eventually abandoned for multiple reasons, including the Partial Test Ban Treaty, which banned nuclear explosions in space, and concerns over nuclear fallout. The idea of rocket propulsion by combustion of explosive substance was first proposed by Russian explosives expert Nikolai Kibalchich in 1881, and in 1891 similar ideas were developed independently by German engineer Hermann Ganswindt. Robert A. Heinlein mentions powering spaceships with nuclear bombs in his 1940 short story "Blowups Happen". Real life propos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Fallout
Nuclear fallout is the residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and the shock wave has passed. It commonly refers to the radioactive dust and ash created when a nuclear weapon explodes. The amount and spread of fallout is a product of the size of the weapon and the altitude at which it is detonated. Fallout may get entrained with the products of a pyrocumulus cloud and fall as black rain (rain darkened by soot and other particulates, which fell within 30–40 minutes of the atomic bombings of Hiroshima and Nagasaki). This radioactive dust, usually consisting of fission products mixed with bystanding atoms that are neutron-activated by exposure, is a form of radioactive contamination. Types of fallout Fallout comes in two varieties. The first is a small amount of carcinogenic material with a long half-life. The second, depending on the height of detonation, is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gas Core Reactor Rocket
Gas core reactor rockets are a conceptual type of rocket that is propelled by the exhausted coolant of a gaseous fission reactor. The nuclear fission reactor core may be either a gas or plasma. They may be capable of creating specific impulses of 3,000–5,000 s (30 to 50 kN·s/kg, effective exhaust velocities 30 to 50 km/s) and thrust which is enough for relatively fast interplanetary travel. Heat transfer to the working fluid ( propellant) is by thermal radiation, mostly in the ultraviolet, given off by the fission gas at a working temperature of around 25,000 °C. Theory of operation Nuclear gas-core-reactor rockets can provide much higher specific impulse than solid core nuclear rockets because their temperature limitations are in the nozzle and core wall structural temperatures, which are distanced from the hottest regions of the gas core. Consequently, nuclear gas core reactors can provide much higher temperatures to the propellant. Solid core nuc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specific Impulse
Specific impulse (usually abbreviated ) is a measure of how efficiently a reaction mass engine (a rocket using propellant or a jet engine using fuel) creates thrust. For engines whose reaction mass is only the fuel they carry, specific impulse is exactly proportional to the effective exhaust gas velocity. A propulsion system with a higher specific impulse uses the mass of the propellant more efficiently. In the case of a rocket, this means less propellant needed for a given delta-v, so that the vehicle attached to the engine can more efficiently gain altitude and velocity. In an atmospheric context, specific impulse can include the contribution to impulse provided by the mass of external air that is accelerated by the engine in some way, such as by an internal turbofan or heating by fuel combustion participation then thrust expansion or by external propeller. Jet engines breathe external air for both combustion and by-pass, and therefore have a much higher specific impulse than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photovoltaics
Photovoltaics (PV) is the conversion of light into electricity using semiconducting materials that exhibit the photovoltaic effect, a phenomenon studied in physics, photochemistry, and electrochemistry. The photovoltaic effect is commercially used for electricity generation and as photosensors. A photovoltaic system employs solar modules, each comprising a number of solar cells, which generate electrical power. PV installations may be ground-mounted, rooftop-mounted, wall-mounted or floating. The mount may be fixed or use a solar tracker to follow the sun across the sky. Photovoltaic technology helps to mitigate climate change because it emits much less carbon dioxide than fossil fuels. Solar PV has specific advantages as an energy source: once installed, its operation generates no pollution and no greenhouse gas emissions, it shows scalability in respect of power needs and silicon has large availability in the Earth's crust, although other materials required in PV system m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heat Engine
In thermodynamics and engineering, a heat engine is a system that converts heat to mechanical energy, which can then be used to do mechanical work. It does this by bringing a working substance from a higher state temperature to a lower state temperature. A heat source generates thermal energy that brings the working substance to the higher temperature state. The working substance generates work in the working body of the engine while transferring heat to the colder sink until it reaches a lower temperature state. During this process some of the thermal energy is converted into work by exploiting the properties of the working substance. The working substance can be any system with a non-zero heat capacity, but it usually is a gas or liquid. During this process, some heat is normally lost to the surroundings and is not converted to work. Also, some energy is unusable because of friction and drag. In general, an engine is any machine that converts energy to mechanical work. Heat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uranium Hexafluoride
Uranium hexafluoride (), (sometimes called "hex") is an inorganic compound with the formula UF6. Uranium hexafluoride is a volatile white solid that reacts with water, releasing corrosive hydrofluoric acid. The compound reacts mildly with aluminium, forming a thin surface layer of AlF3 that resists any further reaction from the compound. UF6 is used in the process of enriching uranium, which produces fuel for nuclear reactors and nuclear weapons. Preparation Milled uranium ore—U3O8 or "yellowcake"—is dissolved in nitric acid, yielding a solution of uranyl nitrate UO2(NO3)2. Pure uranyl nitrate is obtained by solvent extraction, then treated with ammonia to produce ammonium diuranate ("ADU", (NH4)2U2O7). Reduction with hydrogen gives UO2, which is converted with hydrofluoric acid (HF) to uranium tetrafluoride, UF4. Oxidation with fluorine yields UF6. During nuclear reprocessing, uranium is reacted with chlorine trifluoride to give UF6: :U + 2 ClF3 → UF6 + Cl2 Prope ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gaseous Fission Reactor
A gas nuclear reactor (or gas fueled reactor or vapor core reactor) is a proposed kind of nuclear reactor in which the nuclear fuel would be in a gaseous state rather than liquid or solid. In this type of reactor, the only temperature-limiting materials would be the reactor walls. Conventional reactors have stricter limitations because the core would melt if the fuel temperature were to rise too high. It may also be possible to confine gaseous fission fuel magnetically, electrostatically or electrodynamically so that it would not touch (and melt) the reactor walls. A potential benefit of the gaseous reactor core concept is that instead of relying on the traditional Rankine or Brayton conversion cycles, it may be possible to extract electricity magnetohydrodynamically, or with simple direct electrostatic conversion of the charged particles. Theory of operation The vapor core reactor (VCR), also called a gas core reactor (GCR), has been studied for some time. It would have a gas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
