Negative Current-Voltage Characteristics in Hydrogen at High Pressure Using Plane Parallel Electrodes

In conjunction with measurements of current-voltage characteristics in hydrogen, a few characteristics have been obtained which include a region with negative slope. The latter characteristics were obtained with plane parallel electrodes at an electrode separation of 2 cm at a pressure of 400 mm Hg and with three values of externally initiated cathode current. The initial currents ranged from about ${10}^{-11\mathrm{}}$ to ${10}^{-9\mathrm{}}$ amp, and the amplified currents reached values as high as ${10}^{-4\mathrm{}}$ amp. The characteristics corresponding to the larger initial currents become negative at large currents (∼${10}^{-5\mathrm{}}$ amp). The voltage at which a characteristic becomes negative, i.e., the maximum attainable voltage across the electrodes, decreases slightly with increasing initial current. The circuit included a series resistor of 20 megohms.