PARTICLE AND POWER EXHAUST FOR A FUSION PLASMA

For a continuously burning D-T fusion plasma the particle and energy confinement times have to be appropriate since otherwise the produced 4He and the energy cannot be exhausted. The upper limits for the 4He particle confinement parameter neτp(He) are discussed. Comparison with the energy confinement parameter neτE given by the burn condition shows that there is only a limited operational window for a fusion reactor. For a steady state burning D-T plasma, only small concentrations of impurities are tolerable. With increasing impurity concentration, the window becomes smaller and finally closes. © 1990 IOP Publishing Ltd.