A theory for space-charge conditions in high-pressure diodes has been developed which shows that the current obeys a $V^{\frac{3}{2}}$ power relation rather than the usual assumed $V^2$ relation. In addition, the theory predicts that the current in high-pressure diodes, at a constant anode voltage, varies as $p^{-\frac{1}{2}}$. Experimental data, taken in diodes filled with the inert gases, argon, neon, and helium, are presented to illustrate the validity of the theory.

• Received 17 April 1961

DOI:https://doi.org/10.1103/PhysRev.123.1537