Parametric instabilities of damped modes in inhomogeneous plasmas

Technical Report · Sun Apr 01 00:00:00 EST 1973

OSTI ID:4326192

DuBois, D F; Williams, E A

Using WKB analysis it is shown that for three-wave backscattering type parametric instabilities in inhomogeneous plasmas no spatial (convective) growth is possible for undamped modes. if one coupled mode is more heavily damped than the other, then spatial growth is possible in both forward and back-scattering. The spatial amplification factor is that obtained by Rosenbluth only if the pump power is sufficiently above a damping-determined threshold but below a threshold for temporal or absolute instability exists for the backscatter instabilities. For the parametric decay instability at omega /sub o/ = 2 omega /sub pe/ in a finite spatial region only a temporal instability is found but no spatial (convective) growth. (auth)

• Research Organization: Colorado Univ., Boulder (USA). Dept. of Astro-Geophysics
• DOE Contract Number: F44620-73-C-0003
• NSA Number: NSA-29-025759
• OSTI ID: 4326192
• Report Number(s): AD-763737; CU-1005; AFOSR-TR-73-1134
• Resource Relation: Other Information: Orig. Receipt Date: 30-JUN-74
• Country of Publication: United States
• Language: English

Related Subjects

N70700* -Physics-Controlled Thermonuclear Research- Stability
*PLASMA INSTABILITY- PARAMETRIC INSTABILITIES
DAMPING
INHOMOGENEOUS PLASMA
WKB APPROXIMATION