Effects of tritium seeding of advanced fusion fuels

Abstract

Nuclear fusion in DT, 6LiD, 7LiD, p'lB, "BD, 3HeD and other mixtures is considered using a time dependent model based on 44 nuclear reactions, including ion-electron collisions, bremsstrahlung losses and mechanical expansion. The effect of the initial tritium concentration on ignition temperature, neutron production and energy gain is analysed. It is found that tritium seeding can help ignite DD, 3HeD and 7LiD reactions. However, the effect is not so important in aneutronic fuels, such as "BH. In all cases, all possible fusion reactions must be taken into account to optimize the plasma performance, for instance, to minimize the ignition temperature. Another important finding is the possibility of a catalytic regime for tritium in several fuels, without needing external tritium breeding and reducing the tritium inventory.

Synergism between cross-section and profile shaping in beta optimization of tokamak equilibria with negative central shear

“…The conclusions reached are consistent with observations from large tokamak experiments [16-20, 22, 23]. The results have also been applied to obtain record fusion performance in DIII-D [32,33] by utilizing the technique of a controlled transition to H mode in a strongly shaped plasma.…”

“…The peakedness was then controlled by varying M from 1.5 for the broadest profile to M = 5 for the most highly peaked profile considered. This roughly covered the range of the profiles that have been observed in DIII-D [16,22,23,32,33], though some H mode profiles are somewhat broader [23,32], and TFTR [17] has reported some enhanced reverse shear (ERS) profiles with higher inferred peaking factors. To test for the β limit, the parameter p 0 was varied in Eq.…”

Coulomb explosion of nanodroplets drives the conversion of laser energy to nuclear energy

“…where σ (E) is the reaction cross section [31][32][33] and S(E) is the stopping power normalized to the atomic density of the target [36] . The energy dependence of y(E) (inset to Figure 1) over the relevant energy domain up to 15 MeV (which corresponds to the CE energies) is determined by the cumulative contributions of σ (E) and S(E).…”

“…The source consists of deuterons produced by CE of deuterium nano-droplets, ), impinging on a hollow solid cylinder target containing the , , and D atoms. The fusion reactions with the highest cross sections in the relevant energy domains [31–33] were considered. The cylindrical solid target involves or (pure metal or LiF ionic solid) for reactions of D with Li isotopes, and low-temperature () deuterium film or deuterated polymer polyethylene [2,13,26] at room temperature for the reaction.…”

“…The fusion reaction yield per laser pulse is where is the number of deuterons produced from the source and is the average reaction probability: Here is the energy distribution function of the ions with a maximal energy , obtained from scaled electron and ion dynamics (SEID) simulations described in our previous work [24,34,35] , and is the reaction probability per ion with an initial energy penetrating into the solid target, given by where is the reaction cross section [31–33] and is the stopping power normalized to the atomic density of the target [36] . The energy dependence of (inset to Figure 1 ) over the relevant energy domain up to 15 MeV (which corresponds to the CE energies) is determined by the cumulative contributions of and .…”