Limits to the validity of the conventional, classical Nyquist theorem

Research paper by O. Theimer, E. H. Dirk

Indexed on: 13 Apr '08Published on: 13 Apr '08Published in: Il Nuovo Cimento B (1971-1996)


It is suggested that the conventional, classical Nyquist theorem, as given by us, may be only approximately correct and breaks down if the collision frequency is sufficiently large. In the case of fusion plasmas containing impurities, the criterion for the validity of the conventional Nyquist theorem can be more narrowly specified by the conditionν/ωD ≡y ≲ 0.3, whereν is the collision frequency and ωD is the thermal Doppler-shift frequency. This result is obtained by using an adaption of Chambers’ classical method for handling the kinetic theory of matter. Practical applications of our results are mentioned.