Concepts for a Deuterium–Deuterium Fusion Reactor

Abstract

We revisit the assumption that reactors based on deuterium-deuterium (D-D) fusion processes have to be necessarily developed after the successful completion of experiments and demonstrations for deuterium-tritium (D-T) fusion reactors. Two possible mechanisms for enhancing the reactivity are discussed. Hard tails in the energy distribution of the nuclei, through the so-called κ-distribution, allow to boost the number of energetic nuclei available for fusion reactions. At higher temperatures than usually considered in D-T plasmas, vacuum polarization effects from real e + e − and µ + µ − pairs may provide further speed-up due to their contribution to screening of the Coulomb barrier. Furthermore, the energy collection system can benefit from the absence of the lithium blanket, both in simplicity and compactness. The usual thermal cycle can be bypassed with comparable efficiency levels using hadronic calorimetry and third-generation photovoltaic cells, possibly allowing to extend the use of fusion reactors to broader contexts, most notably maritime transport.

The challenges of nuclear fusion reactor

“…Unlike PP cycle, CNO cycle starts heavier element 12 C which produced by triple alpha process which three alpha particles are fused into carbon 4 He + 4 He → 8 Be , 8 Be + 4 He → 12 C * + 2γ…”

“…⟨𝛔𝒗⟩ is reactivity and 𝑻 is temperature [4].In Figure1, D T fusion has much higher cross section which means the possibility of reaction is higher than D D fusion over same temperature. With κ distribution, D T fusion at relatively low temperature, the reactivity gains of two orders of magnitude compare with the Boltzmann energy distributions[4]. In fact, κ distribution provide a straightforward replacement of the Maxwell distribution for systems out of the thermal equilibrium such as space plasmas[5].…”

Enhancement of fusion reactivity under non-Maxwellian distributions: effects of drift-ring-beam, slowing-down, and kappa super-thermal distributions

“…In 2006, Nakamura et al [11] confirmed that non-Maxwellian knock-on perturbations caused by close collisions between alpha particles and background ions would result in reactivity enhancement in fusion reactions. Subsequently, studies on the effect of reactant distributions with high-energy tails in fusion reactions, such as the kappa distribution [17][18][19], have been conducted. Overall, these findings suggest that non-Maxwellian distributions have a significant impact on fusion reactivity and open up new avenues for enhancing fusion efficiency.…”

Non-Maxwellian rate coefficients for electron and ion collisions in Rydberg plasmas: implications for excitation and ionization

“…Among the various assumptions in these models, the fact that colliding particles may not share energies according to a Maxwell-Boltzmann (MB) probability distribution, as far as we know, has never been systematically scrutinized in the context of plasma fusion, apart from the possible impact in terms of nuclear fusion reactivities (Onofrio 2018). This is at variance with the astrophysical plasmas for which deviations from MB have been discussed (Nicholls, Dopita & Sutherland 2012;Nicholls et al 2013;Storey & Sochi 2014Draine & Kreisch 2018).…”