Watanabe K, Dairaku M, Tobari H, Kashiwagi M, Inoue T, Hanada M, Jeong S H, Chang D H, Kim T S, Kim B R, Seo C S, Jin J T, Lee K W, In S R, Oh B H, Kim J, Bae Y S
Japan Atomic Energy Agency, 801-1 Mukouyama, Naka, Ibaraki-ken 311-0193, Japan.
Rev Sci Instrum. 2011 Jun;82(6):063507. doi: 10.1063/1.3599585.
A plasma generator for a long pulse H(+)/D(+) ion source has been developed. The plasma generator was designed to produce 65 A H(+)/D(+) beams at an energy of 120 keV from an ion extraction area of 12 cm in width and 45 cm in length. Configuration of the plasma generator is a multi-cusp bucket type with SmCo permanent magnets. Dimension of a plasma chamber is 25 cm in width, 59 cm in length, and 32.5 cm in depth. The plasma generator was designed and fabricated at Japan Atomic Energy Agency. Source plasma generation and beam extraction tests for hydrogen coupling with an accelerator of the KSTAR ion source have been performed at the KSTAR neutral beam test stand under the agreement of Japan-Korea collaborative experiment. Spatial uniformity of the source plasma at the extraction region was measured using Langmuir probes and ±7% of the deviation from an averaged ion saturation current density was obtained. A long pulse test of the plasma generation up to 200 s with an arc discharge power of 70 kW has been successfully demonstrated. The arc discharge power satisfies the requirement of the beam production for the KSTAR NBI. A 70 keV, 41 A, 5 s hydrogen ion beam has been extracted with a high arc efficiency of 0.9 -1.1 A/kW at a beam extraction experiment. A deuteron yield of 77% was measured even at a low beam current density of 73 mA/cm(2).
已研制出一种用于长脉冲H(+)/D(+)离子源的等离子体发生器。该等离子体发生器设计用于从宽度为12厘米、长度为45厘米的离子引出区域产生能量为120keV的65A H(+)/D(+)束流。等离子体发生器的结构是带有钐钴永磁体的多尖桶型。等离子体腔的尺寸为宽25厘米、长59厘米、深32.5厘米。该等离子体发生器由日本原子能机构设计和制造。在日韩合作实验协议下，已在KSTAR中性束试验台上对与KSTAR离子源加速器耦合的氢进行了源等离子体产生和束流引出测试。使用朗缪尔探针测量了引出区域源等离子体的空间均匀性，获得了与平均离子饱和电流密度偏差±7%的数据。已成功演示了在70kW电弧放电功率下长达200秒的等离子体产生长脉冲测试。电弧放电功率满足KSTAR中性束注入器束流产生的要求。在束流引出实验中，以0.9 - 1.1A/kW的高电弧效率引出了70keV、41A、5秒的氢离子束流。即使在73mA/cm(2)的低束流密度下，也测量到氘产率为77%。
