The Child-Langmuir collision laws for the cathode sheath of glow discharge in nitrogen

This paper reports the measurements of dc cathode sheath thickness d together with the voltage drop U across it at different current I values in nitrogen. For the case of a narrow gap when the discharge consists only of a cathode sheath and a negative glow almost all voltage applied across the electrodes drops across the cathode sheath. We observe that at the nitrogen pressure p 1.5 Torr the Child–Langmuir collision law version characterized by the constant ion mobility is valid. Within the pressure range of 1