Two-fluid burning-plasma analysis for magnetic confinement fusion devices

Abstract

The two-fluid, Lawson-type ignition model of (Guazzotto and Betti 2017 Phys. Plasmas 24 082504) for nuclear fusion concepts is extended to burning-plasmas. Numerical estimates for the Lawson product t p Ei tot are obtained for different values of the gain factor Q and different plasma conditions. Namely, different assumptions are made for the various energy confinement times in the model and different density and temperature profiles are considered. It is found that it is easier to reach the burning plasma condition with peaked profiles. A technique for comparing pure-deuterium (DD) 'equivalent' experimental discharges with the predictions of our model for deuterium-tritium (DT) burning plasma discharges is described. This is done through the introduction of 'no−α' quantities using a procedure similar to the one used in inertial confinement fusion. Using tokamaks as a meaningful example, an experimental fit for the energy confinement time is introduced in the calculations and shown to have a considerable effect on the results, qualitatively changing the thermal stability of the system and the equivalent Lawson product estimates of pure deuterium plasmas. Moreover, if the energy confinement time depends on the heating power as in experimental scalings, the equivalent t p Ei tot in DD discharges is higher than the corresponding t p Ei tot in a DT plasma.

Plasma shielding effects on nuclear spectra: $^{18}$Ne application

“…Plasmas are currently used in space exploration and fusion research, as well as in many research areas, and it is highly likely to be used in a much wider and more effective way in the future. [16][17][18][19]. Due to the shielding effect of the plasma, the atomic systems in it exhibit quite different properties compared to the atomic systems without plasma (Pure Coulomb interacting) [20][21][22].…”

“…We have focused on the plasma-shielding of the interactions of the valence nucleons with the core nucleus in order to investigate plasma effects on the nuclear structure. For this aim, the applications have been carried out for 18 Ne nucleus due to its both even-even structure and in order to minimize the shielding contributions that can be arised from possible two-body interactions. Another reason why this nucleus was chosen as an application is that the shielding effect of the plasma medium on interaction only between protons is observable.…”

“…It has been observed that proton spe levels obtained by using WS potential are sensitive to plasma shielding parameters (λ,a and b), and the localizations of these spes levels that will be employed in SM calculations are shifted by changing plasma shielding effects. Also, it should be pointed out that 18 Ne nucleus plays an important role due to its importance for resonant component of 14 O(α, p) 17 F and 14 F(p, γ) 18 Ne reactions in the astrophysical processes in where the plasma effects are strong, as mentioned before [33][34][35][36][37]. In our SM calculations, 16 O is assumed as an inert core nucleus and it is considered that active particles are distributed in d 5/2 , s 1/2 and d 3/2 single-particle orbits.…”

“…In our SM calculations, 16 O is assumed as an inert core nucleus and it is considered that active particles are distributed in d 5/2 , s 1/2 and d 3/2 single-particle orbits. Although experimental information about 18 Ne, which is a member of the T z = −1 isobaric spin triplet with mass number A = 18, is still insufficient, the low excited levels could be partially determined experimentally [37].…”

“…Excited energy spectrum of the 18 Ne proton-rich isotope is similar to 16 O that is its mirror partner, due to the fact that the force between nucleons is independent of charge, and the effect of the Coulomb interaction is feeble. Since the s 1/2 orbital is important for nuclei around A = 20, the excited energies of some states in protonrich nuclei can be exhibited inconsistencies compared to their mirror cases [38].…”