Extraction of negative hydrogen ions produced with aluminum plasma grid

Physics of Plasmas, Volume 28, Issue 3, March 2021. Negative hydrogen ions are produced and extracted using an aluminum plasma grid, without cesium through irradiation with hydrogen plasma. The negative ion amount increases sharply, up to ∼115 μA·cm−2, at a discharge power of 1 kW with an electric field downstream of the grid. These negative ions are extracted with high purity. In addition, it is suggested that negative ions are produced by positive hydrogen ions and hydrogen atoms. As high-density plasmas enhance the negative ion production, the current density of negative ions is expected to increase with plasma discharge power.