To enable better designing of inductively coupled plasma (ICP) cathodes, this study experimentally investigated the ignition and electron emission performances of an ICP cathode as functions of the orifice diameter, shape of the electrode used for ion collection, and total number of coils. Because the plasma ignition in an ICP cathode obeys Paschen’s law, decreasing the orifice diameter enhances the ignition performance. However, excessive orifice narrowing decreases the electron emission current from the cathode. Therefore, an optimum orifice diameter exists that balances the ignition and electron emission performances. In addition, it is preferable for the electrode used for ion collection to have a large slit for electric field penetration to enhance the ignition performance. On the other hand, when the orifice diameter is properly selected, increasing the ion collection area by narrowing the slit improves the electron emission performance. Thus, the electrode shape should be designed to achieve a balance between the plasma ignition and electron emission. Finally, increasing the total number of coils enhances the ignition performance. However, owing to the power loss caused by ohmic heating in the coil, an optimum total number of coils exists that maintains the adequate electron emission performance.
Dependence of Cathode Configuration on Performance in an Inductively Coupled Plasma Cathode
Journal of Propulsion and Power ; 34 , 3 ; 668-678
2018-05-01
Conference paper , Article (Journal)
Electronic Resource
English