Experiment Study on the Neutralizer of 10cm ECRIT with Nitrogen Gas

Electron cyclotron resonance ion thruster (ECRIT) with a diameter of 10 cm can operate on multiple types of gases and it is feasible to be applied to air-breathing electric propulsion systems. The study on the neutralizer of the ECRIT running on nitrogen gas is the basis for the study on the ECRIT running on nitrogen-oxygen mixed gas. When the ECR neutralizer of typical 10 cm ECRIT running on xenon gas runs on nitrogen gas, the extracted electron current is reduced, because ions tend to drift out of the neutralizer, due to the lower molecular weight of nitrogen. The typical neutralizer is no longer suitable to run on nitrogen gas. In this paper, based on the 10cm typical ECR neutralizer, in order to inhibit ion drift out of the neutralizer and improve the performance of electron extraction, a bipolar ECR neutralizer suitable to run on nitrogen gas is experimentally studied. The results show that under the conditions of gas mass flow rate of 0.04mg/s and input power of 10W, the anode voltage required by the typical ECR neutralizer running on nitrogen gas is 150V when the extracted electron current is 134mA. However, the bipolar ECR neutralizer requires only 50V anode voltage, which decreases by about 67%. When the anode voltage is 40V, the power loss of the typical ECR neutralizer is 1204.82W/A, while the power loss of the bipolar ECR neutralizer is 95.23W/A, which is about 8.3% of the former. The ion shielding effect of the bipolar ECR neutralizer running on nitrogen gas is remarkable and the electron extraction performance is improved.