Development of ion source discharge chamber for the 5 MW neutral beam heating line on HL-2M device
-
摘要: 为了给HL-2M装置建设一条5 MW中性束加热束线，开展了中性束加热用热阴极弧放电离子源放电室的研制。这条中性束束线包含4套80 kV/45 A/5 s离子源，放电室的设计指标为850 A/5 s。首先采用CST软件中的电磁工作室对特定几何结构的放电室会切磁场进行了模拟计算，得到了会切磁场分布，验证了会切磁场布局的合理性。针对放电室加工工艺和实验过程中局部拉弧等问题，对放电室结构进行了不断改进。放电室侧壁由40列会切磁体改为7圈环形磁体，阴极灯丝结构从灯丝板结构最终改为陶瓷可伐结构，并且在放电室和加速器之间增加了陶瓷屏蔽。在阴极板结构放电室和阴极陶瓷可伐结构放电室内都获得了正常的弧放电。最终定型的放电室采用周边7圈环形会切磁体和陶瓷可伐结构。在定型的放电室内达到了5 MW中性束束线离子源弧放电的指标。弧放电时间接近5 s，最大弧放电电流达到1000 A。Abstract: To construct a 5 MW neutral beam heating beamline for HL-2M device, the development of the discharge chamber of the hot cathode arc discharge ion source for neutral beam heating was carried out. The neutral beamline contains four sets of 80 kV/45 A/5 s ion sources, and the discharge chamber design index is 850 A/5 s. Firstly, the electromagnetic studio in CST software was used to simulate the cusp magnetic field of the discharge chamber with specific geometric structure, and the cusp magnetic field distribution was obtained, which verified the rationality of cusp magnetic field layout. To solve the problems in the process of the discharge chamber and the localized arcing in the experiment, the structure of the discharge chamber was improved. The side wall of the discharge chamber changed from 40 rows of cusp magnets to 7 rings of cusp magnets, the cathode structure changed from the filament plate structure to the ceramic kovar structure, and a ceramic shield was added between the discharge chamber and the accelerator. Normal arc discharge was obtained in both the cathode plate discharge chamber and the cathode ceramic kovar discharge chamber. The final shaped discharge chamber adopted 7-ring cusp magnets and ceramic kovar cathode structure. The arc discharge index of the 5 MW neutral beamline ion source was achieved in the final shaped discharge chamber. The arc discharge time was close to 5 s, and the maximum arc discharge current reached 1 000 A.
-
Key words:
- HL-2M device /
- neutral beam heating /
- ion source /
- arc chamber
-
图 5 放电室内局部拉弧引起的烧灼痕迹
Figure 5. Burning marks caused by local arcing in the discharge chamber
-
[1] Kadomtsev B B, Troyon F S, Watkins M L, et al. Tokamaks[J]. Nuclear Fusion, 1990, 30(9): 1675. doi: 10.1088/0029-5515/30/9/003 [2] Duesing G, Altmann H, Falter H, et al. Neutral beam injection system[J]. Fusion Technology, 1987, 11(1): 163-202. doi: 10.13182/FST87-A25004 [3] Fujita T. High-performance experiments towards steady-state operation in JT-60U[J]. Plasma Physics and Controlled Fusion, 1997, 39, B75. [4] Okumura Y, Fujiwara Y, Inoue T, et al. High power negative ion sources for fusion at the Japan Atomic Energy Research Institute[J]. Review of Scientific Instrument, 1996, 67(3): 1092-1097. doi: 10.1063/1.1146766 [5] Cao Jianyong, Wei Huiling, Liu He, et al. Empirical scaling law of neutral beam injection power in HL-2A tokamak[J]. Chinese Physics Letters, 2015, 32: 052902. doi: 10.1088/0256-307X/32/5/052902 [6] Cao J Y, Wei H L, Zou G Q, et al. Conceptual design of 5MW-NBI injector for HL-2M tokamak[J]. Fusion Engineering and Design, 2013, 88: 872-877. doi: 10.1016/j.fusengdes.2013.03.034 [7] Liu H, Cao J Y, Wei H L, et al. The latest progress of the 1st NBI beamline on HL-2M Tokamak[J]. Fusion Engineering and Design, 2017, 123: 448-452. doi: 10.1016/j.fusengdes.2017.02.109 [8] Wei H L, Cao J Y, Rao J, et al. The dependence of extracted current on discharge gas pressure in neutral beam ion sources on HL-2A tokamak[J]. Review of Scientific Instruments, 2012, 83: 023302. doi: 10.1063/1.3681446 [9] Hu C D, Xu Y J, Xie Y H, et al. The recent development of the EAST neutral beam injector[J]. Chinese Physics Letter, 2015, 32: 052901. doi: 10.1088/0256-307X/32/5/052901 [10] Xu Y J, Hu C D, Liu S, et al. Preliminary experimental study of ion beam extraction of EAST neutral beam injector[J]. Chinese Physics Letter, 2012, 29: 035201. doi: 10.1088/0256-307X/29/3/035201 [11] Chen W, Yu L M, Ding X T, et al. Core-localized Alfvénic modes driven by energetic ions in HL-2A NBI plasmas with weak magnetic shears[J]. Nuclear Fusion, 2016, 56: 036018. doi: 10.1088/0029-5515/56/3/036018 [12] Chen W, Ding X T, Yu L M, et al. Observation of energetic-particle-induced GAM and nonlinear interactions between EGAM BAEs and tearing modes on the HL-2A tokamak[J]. Nuclear Fusion, 2013, 53: 113010. doi: 10.1088/0029-5515/53/11/113010 [13] 曹建勇, 魏会领, 刘鹤, 等. HL-2M装置中性束注入加热系统研制进展[J]. 强激光与粒子束, 2018, 30:106001. (Cao Jianyong, Wei Huiling, Liu He, et al. Latest progress of development of the neutral beam injection heating system on HL-2M Tokamak[J]. High Power Laser and Particle Beams, 2018, 30: 106001 [14] 魏会领, 曹建勇. 一种离子源放电室内夹紧螺母灯丝支架的屏蔽结构: CN106935472B[P]. 2018-11-30.Wei Huiling, Cao Jianyong. Shielding structure for filament support adopting clamping nuts in ion source discharge chamber: CN106935472B[P]. 2018-11-30 [15] 魏会领, 曹建勇. 一种离子源放电室阴极灯丝杆的连接和冷却结构: CN106935460B[P]. 2018-09-28.Wei Huiling, Cao Jianyong. Ion source discharge chamber cathode filament rod connection and cooling structure: CN106935460B[P]. 2018-09-28 [16] 魏会领, 曹建勇. 一种离子源放电室与加速器之间的陶瓷屏蔽结构: CN106935471B[P]. 2018-11-30.Wei Huiling, Cao Jianyong. Ceramic shielding structure between ion source discharge chamber and accelerator: CN106935471B[P]. 2018-11-30 -
下载:
点击查看大图
图(8)
计量
- 文章访问数: 1146
- HTML全文浏览量: 448
- PDF下载量: 49
- 被引次数: 0
