| Autor: |
Kever, H., Reiter, Detlev, Wolf, Gerd H. |
| Jazyk: |
angličtina |
| Rok vydání: |
1990 |
| Zdroj: |
Jülich : Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag, Berichte des Forschungszentrums Jülich 2342, 16 p. (1990). |
| Popis: |
The burn condition for D-T plasmas is derived in a form which accounts for the stationary helium concentration being selfconsistently determined by the coupling of thefusion power and helium production. The ratio of the global $\alpha$-particle confinement time $\tau^{*}_{\alpha}$ (defintion in the text) to the energy confinement time $\tau_{E}$ is taken as a quantity characterizing the prevailing confinement arid exhaust regime. lt is shown that for an ignited and stationary burning D-T plasma this ratio needs to remain sufficiently below 15 (or below 10 for typical impurity concentrations). This poses a lower limit to the required helium exhaust efficiency and indieates that operational regimes might be desirable where the internal particle confinement time does not diverge too far from and in excess of the energy confinement time, and where the boundary layer - e.g. through high particle density and outward flow acts as a suffizient shield against recycled $\alpha$-particles. lt is further demonstrated that for any given temperature (and for otherwise equal overall exhaust and recycling conditions) either burning can be achieved at two quite different values of the fusion parameter (triple product n $\cdot$ T$\cdot$ r$_{E}$) and ash concentrations (one at Iow concentrations in the range 5 - 20 %, the other in the range of 20 - 35 %) or not at all. A similar evaluation applied to the D-$^{3}$He fusion reaction leads to even rnore stringent limits an the ratio $\tau^{*}_{\alpha}$/$\tau_{E}$, which must be smaller by a factor 3 to 4 compared to the D-T case. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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