X-Ray Induced Total Ionization of Air

X-ray-induced total ionization of air is investigated by solving rate equations of atoms and ions of nitrogen and oxygen. Time distributions of components in the whole ionization process are given by recording respective number density. A clear population inversion is observed as we change the blackbody temperature
$T_{b}$
of the incident X-ray. Total ionization time
$t_{\mathrm{ end}}$
of the whole system and each ion succession is calculated. We find that
$t_{\mathrm{ end}}$
is sensitive to
$T_{b}$
of the incident X-ray and an optimal ionization temperature
$T_{\mathrm{ opt}}$
exists at which
$t_{\mathrm{ end}}$
reaches its minimum. We have given the
$T_{\mathrm{ opt}}$
of nitrogen and oxygen ionization, respectively. The result indicates that deviation from the
$T_{\mathrm{ opt}}$
will lead to a severe multiplication of total ionization time.