Application of double grid cathode for improvement of neutron yield in IEC device

Recently, in order to improve a neutron yield in an Inertial Electrostatic Confinement (IEC) device operating at a glow discharge mode, various techniques have been performed, such as injection of plasma ion source, introduction of multi-grid configuration, coating electrode with titanium, magnetic assisted IEC device, and so on. However, these techniques lead to the complicated structure of a device which limits the flexibility of the shape design and are not easy to make an IEC device compact and portable. In this research, we have proposed a new configuration for the yield improvement without additionally external ion sources; an application of a double grid cathode. A neutron yield in an IEC device is proportional to the ion current and is closely related to the potential well structure inside the cathode. Therefore, when a double grid cathode is applied to an IEC device, the high electric field strength near the cathode is generated and thus, the high neutron production rate will be obtained. These facts are verified as compared with the ion current calculated at both single and double grid cathode shape. Additionally, ion´s lives and trajectories are examined in various grid cathode configurations and cathode voltages by using a numerical simulation.