@misc{oai:repo.qst.go.jp:00085183,
 author = {Masashi, Kisaki and 木崎 and 永岡賢一 and Jelle, Slief and 波場泰昭 and 中本崚也 and 津守克嘉 and 中野治久 and 池田勝則 and 藤原大 and 長壁正樹 and Masashi, Kisaki},
 month = {May},
 note = {Negative ion sources for fusion are required to generate the stable high-energy and high-current negative ion beam with long pulse duration more than 1000 s. To satisfy these requirements, it is essential to minimize the heat load on accelerators. The key issue for managing the heat load is to understand the mechanism of the meniscus formation in negative ion sources. In the paper, negative ion beam optics are studied in both real and phase spaces to get a better understanding of the meniscus formation. Plasma parameters and the negative ion beam in a Caesium-seeded negative ion source are measured simultaneously, and correlation between the plasma conditions and the beam optics are investigated in order to elucidate a dominant plasma parameter determining the meniscus shape. In addition, the spatial distribution of negative ions in the vicinity of the meniscus is extracted through a backward trajectory calculation from the accelerator exit to the meniscus using experimental data as an input. The negative ion trajectory was calculated taking into consideration the negative ion distribution based on the backward calculation, and the influence of the non-uniformity of negative ion profile on the meniscus formation is discussed., 28th IAEA Fusion Energy Conference},
 title = {Study of negative ion beam optics in real and phase spaces},
 year = {2021}
}