Results
We first performed two runs with different initial ion thermal velocities
Vi.
One is with Vi = 2.0, and the other is with Vi = 0.1.
We assumed the same density ratio R = 0.5 for these runs.
Namely, two electron beams have the same thermal velocity with drift
velocities
Vd/2 and -Vd/2.
The evolution of the instability is shown by the phase diagrams of particle
in the ,x - vx space at different times.
The runs with
Vi = 2.0 and 0.1 are shown
on the graphic data
GRL94_R05_warm_ion
and
GRL94_R05_cold_ion
, respectively.