Experimental research on field emission of carbon fibe

Electric carbon fiber is a promising material to emit cold electron under intensive electric field. Experiment was conducted to test carbon fiber’s emission at the pressures of 0.1 MPa, 10-1 Pa and 10-5 Pa. The diode gap between the fiber tip and the electron collecting anode was about 5 mm. In atmosphere, the applied voltage and the emitted current have a Fowler-Nordheim relation. According to Fowler-Nordheim theorem, the field intensified factor was 3.75×105 when the voltage was 7 kV and the current was 61.4 μA. In low vacuum (about 10-1 Pa) condition, the anode collected current only less than 10 μA under 20 kV. In high vacuum (about 10-5 Pa) condition, the anode collected larger anode current up to 300 μA without flashover, the relation between voltage and current was close to the