https://doi.org/10.1140/epjd/e2016-60497-x
Regular Article
Analysis of MHD instabilities by asymptotic methods
WKB expansion
1 ENEA guest, C.R. Frascati, via E.
Fermi, 45, 00044 Frascati, Roma, Italy
2 ENEA-FSN, C.R. Frascati, via E.
Fermi, 45, 00044 Frascati, Roma, Italy
a e-mail: brunellotirozzi@gmail.com
b e-mail: camillo.tassi@gmail.com
Received:
2
September
2015
Published online:
29
March
2016
The m = 1 resistive mode for a tokamak plasma with large aspect ratio is considered: the dynamic equations in a resistive layer are solved by means of an asymptotic expansion for values of the growth rate in a suitable range. The eigenvalues characterizing the perturbation are found by means of a series expansion and it is shown that the main contribution to the expression of the eigenvalues is given by the first and the second order of this expansion. This method is different from the one used in the paper [G. Ara et al., Ann. Phys. 112, 443 (1978)], and can be applied in more general situations.
Key words: Plasma Physics
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2016
