Observation of stimulated electron-acoustic-wave scattering.
A diffraction-limited laser interacts with a plasma whose conditions are uniform on the scale of the focused laser spot. Two distinct, narrow waves are observed in the backscattered spectrum with phase velocities of v(phi)/v(e) = 1.4+/-0.08 and 4.2+/-0.1, where v(e) is the electron thermal speed. The high-velocity wave is ordinary stimulated Raman scattering (SRS) from a Langmuir wave. The low-velocity wave corresponds to stimulated scattering from an electron-acoustic wave (SEAS), and implies strong electron trapping. Previous SRS data from low-density plasmas are reinterpreted in terms of SEAS.
Montgomery
D S
DS
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Focia
R J
RJ
Rose
H A
HA
Russell
D A
DA
Cobble
J A
JA
Fernández
J C
JC
Johnson
R P
RP