Since a fusion reactor using the Deuterium-Tritium fuel cycle cannot be a source of clean energy because of the deleterious effects of energetic neutrons carrying 80% of the energy output, and it is ...very doubtful that it will be able to achieve Tritium self-sufficiency because of an extremely problematic and still unproven breeding procedure, this paper proposes a new reactor scheme capable of confining hot and dense plasmas using the Deuterium – Helium-3 fuel cycle. Such a reactor must be considered a source of clean energy because of its very low level of neutrons production, and its fuel is available in large quantity since we can get the needed Deuterium from seawater and likewise Helium-3 from the moon, as it was found from the samples of lunar soil brought back by the astronauts of the Apollo Mission. The proposed reactor consists of two 100 m long cylindrical plasmas, connected by semicircular sections to form a racetrack configuration. It should be capable of producing from 16 to 20 GW of fusion power when operating with an electron density of 3 × 1020 m−3, a magnetic field of 10 T and average temperatures from 40 to 45 keV. Out of this power, up to 10 GW will be used for replacing the loss of electron energy from bremsstrahlung radiation, with a consequent reduction in the reactor power output. However, such a loss could be mitigated by a partial recovery of the energy plasma radiation.
We report the observation of a correlation between shear Alfvén eigenmode activity and electron transport in plasma regimes where the electron temperature gradient is flat, and thus the drive for ...temperature gradient microinstabilities is absent. Plasmas having rapid central electron transport show intense, broadband global Alfvén eigenmode (GAE) activity in the 0.5-1.1 MHz range, while plasmas with low transport are essentially GAE-free. The first theoretical assessment of a GAE-electron transport connection indicates that overlapping modes can resonantly couple to the bulk thermal electrons and induce their stochastic diffusion.
The replacement of the burning of fossil fuels in power plants with other forms of clean energy, for example, that of a tokamak fusion reactor employing the deuterium-tritium cycle, like ITER, would ...contribute enormously to the mitigation of climate change. Unfortunately, for such a type of fusion reactor, we expect the neutrons, which carry 80% of the fusion power with energies seven times larger than those of neutrons of fission reactors, to cause serious radiation damage with possible fracture of the blanket modules and the reactor wall. Hence, before contemplating the use of tokamaks for replacing fossil fuels of conventional power plants, we need a thorough investigation of the damage caused by neutrons in high-power tokamak reactors. Unfortunately, ITER will not provide any exhaustive information since it is neither a high power density tokamak nor a reactor. However, a rise in toroidal magnetic field by a factor of 2 would bring the fusion power of ITER to 8 GW and allow an investigation of the damage caused by neutrons to internal components and the reactor wall.
With the goal of reducing the radiation damage and radioactive waste that will occur in a tokamak reactor using the deuterium-tritium cycle, this paper proposes a new magnetic scheme capable of ...confining hot and dense deuterium-helium3 plasmas. It consists of two 200-m-long cylindrical plasmas connected by semicircular sections to form a racetrack configuration. The reactor should be capable of producing from 7.8 to 13 GW of fusion power when operating at electron densities of 2 × 10
20
m
−3
, temperature 40 keV, and density ratios of the two reactants from 1:2 to 2:1.
The paper describes a fusion reactor scheme consisting of two 200-m-long magnetic mirrors with a ratio of two connected by semicircular sections to form a racetrack configuration. The two most ...serious problems of magnetic mirrors, magnetohydrodynamic stability and end losses, are solved by minimizing the negative curvature of the mirror magnetic field lines and using helical windings in the curved sections to add a positive curvature and strong shear to the magnetic field lines at and beyond the mirror throat and for confining the mirror end losses. The reactor should be capable of producing at least 13 GW of fusion power when operating in deuterium-tritium at the same plasma density and temperature as ITER.
Measurements with coherent scattering of electromagnetic waves in plasmas of the National Spherical Torus Experiment indicate the existence of turbulent fluctuations in the range of wave numbers k ...perpendicular rho(e)=0.1-0.4, corresponding to a turbulence scale length nearly equal to the collisionless skin depth. Experimental observations and agreement with numerical results from a linear gyrokinetic stability code support the conjecture that the observed turbulence is driven by the electron-temperature gradient.
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