A: ionization coefficient

B: attachment coefficient

d: inter-electrode distance

e: electron charge

E: electric field intensity

E0: initial electric field intensity

Ebr: breakdown field strength

Fbr: braking force

f0: propagation frequency

J: current density

kB: Boltzmann constant

me: electron mass

ni: number density of ith component

ne: electron density

Ng: background gas density

qe: electron charge

Qi: collision cross section of ith component

r: electron position vector

rs: streamer radius

t: time

Tfl: fire temperature

ud: drift velocity

us: streamer velocity


α: ionization rate

β: attachment rate

δ: ionization potential factor

γ: electron affinity factor

σ: electrical conductivity

σi: imaginary component of σ

σr: real component of σ

φeff: effective collision frequency

ω = 2πf0: angular frequency


d/dt: time derivative

i = 1 : imaginary