On the Renormalization of Particle Kinetic Equation in Plasma Turbulence Theory
* SPEAKERS
Name
Affiliation
E-mail
Peter H. Yoon
* HOST(Applicant)
Name
Affiliation
E-mail
-
* DATE / TIME
2003-11-14, 10:00-11:00 am
* PLACE
APCTP, Science Bldg. Ⅲ #201, Postech
* ABSTRACT
Nonlinear plasma turbulence theory developed by the former Soviet scientists from the early days of plasma physics research assume that perturbation expansion of physical quantities with the wave amplitude as the smallness parameter is possible. First-order and third-order truncations of the perturbation expansions have respectively resulted in quasilinear theory and weak turbulence theory. These theories have been very successfully applied to many physical problems. However, in 1966 Dupree first
pointed out that the perturbation expansion beyond third order leads to divergences, and thus, a renormalization was required. For this reason, the development of renormalized plasma turbulence theory has become one of the most advance research topics in nonlinear plasma theory. Many methods have been introduced, among which the direct-interaction-approximation (DIA) borrowed from Kraichnan's Navier-Stokes turbulence theory has played a prominent role. One of the key results in plasma renormalized theories is to replace the delta-function-like resonance denominators by renormalized resonance function. In this lecture, I will outline what happens if one actually attempts to partially sum up the most divergent perturbation series (as Weyl did for Navier-Stokes fluid turbulence problem). The renormalized theory which results from direct summation of most divergent perturbation series will show that quasilinear or weak turbulence theories are quite valid, and that the DIA theory over emphasizes the importance of resonance broadening.
