Moment equations

∂f-+ v∂f-+ -qsE ∂f-= 0, ∂t ∂x ms ∂v

(141)

∑ ( ) ∂NpSx-(x−-xp)Sv(v−-vp)+ v∂NpSx-(x−-xp)Sv(v−-vp)+ -qsE ∂NpSx(x-−-xp)Sv(v-− vp) = 0, p ∂t ∂x ms ∂v

(142)

—tmp–

f = f0 + δf

(143)

dδf-= − df0- dt dt

(144)

dδf∕f 1 df ------= − ---0- dt f dt

(145)

dδf∕f f 1 df ------= − 0-----0 dt f f0dt

(146)

dw- f-−-δf-1 df0- dt = − f f0 dt

(147)

dw- -1 df0- dt = − (1− w)f0 dt

(148)

to be deleted–