化学イオン化
CH 4 + e − ⟶ CH 4 + ∙ + 2 e − {\displaystyle {\ce {CH4{}+e^{-}->CH4^{+\bullet }{}+2e^{-}}}}
CH 4 + CH 4 + ∙ ⟶ CH 5 + + CH 3 ∙ {\displaystyle {\ce {CH4{}+CH4^{+\bullet }->CH5+{}+CH3^{\bullet }}}}
CH 4 + CH 3 + ⟶ C 2 H 5 + + H 2 {\displaystyle {\ce {CH4 + CH3^+ -> C2H5+ + H2}}}