$ifimpact ion

$ifimpact_ion is a function to turn on the impact ionization. It is a field and current dependent function which will rely on the electric field in the simulation program.

The impact ionization generation rate is decided by

$G_{i}mpact=\frac{|Jn|}{e}\times {\alpha }_n+\frac{|Jp|}{e}\times {\alpha }_p$

${\alpha }_n=a_n*exp(-\left|{\left(\frac{b_n|Jn|}{\overrightarrow{E}\cdot \overrightarrow{Jn}}\right)}^{c_n}\right|)$

${\alpha }_n=a_p*exp(-\left|{\left(\frac{b_p|Jp|}{\overrightarrow{E}\cdot \overrightarrow{Jp}}\right)}^{c_p}\right|)$

The way to input this command is

$ifimpact_ion
$a_n{b}_n{c}_n{a}_p{b}_p{c}_p$