Simulation study of the radiative divertor under different gas puffing locations for CFETR

doi:10.16568/j.0254-6086.202004008

Abstract

Abstract: The simulation study of the radiative divertor for China Fusion Engineering Test Reactor (CFETR) was performed with argon impurity puffing using the edge plasma numerical simulation code package SOLPS. The simulated Zeff at the core-edge boundary (ρ=0.9) of the outer mid-plane are 2.8, 3.1, 3.4 and 2.7, respectively, for four different gas puffing schemes (deuterium and argon mixed gas puffing from upstream; deuterium and argon mixed gas puffing from outer divertor; deuterium and argon mixed gas puffing from inner divertor; deuterium gas puffing from upstream and argon puffing from outer divertor) with fixed total radiated power (P_rad~170MW). The simulation results are similar to the experimental observation on DIII-D and C-MOD. Better impurity screening can be achieved with deuterium puffed from upstream due to the increased background plasma flow in the scrap-off layer, while the puffing location of argon has a minor influence on the simulation results since divertor target recycling is the major impurity source.

Key words: SOLPS, CFETR, Radiative divertor, Impurity screening

摘要： 利用边缘等离子体数值模拟程序SOLPS对氩杂质注入下中国聚变工程试验堆装置辐射偏滤器运行模式进行了模拟研究。在达到相同的总辐射功率(P_rad~170MW)时，四种不同充气方案下(从上游充入氘氩混合气体，从外偏滤器充入氘氩混合气体，从内偏滤器充入氘氩混合气体，从上游充入氘气的同时从外偏滤器充入氩气) 在外中平面的模拟区域内边界(ρ=0.9)处的有效离子电荷数Zeff分别为2.8、3.1、3.4、2.7。模拟结果与DIII-D及C-MOD的实验结论一致。当从上游充入氘气时，可以增强刮削层中的本底等离子体流，从而得到相对更好的杂质屏蔽效果；同时由于偏滤器靶板再循环杂质源占主导作用，注入氩气的位置对于模拟结果影响不大。

关键词: SOLPS, CFETR, 辐射偏滤器, 杂质屏蔽

CLC Number:

TL62+1

ZHOU Yi-fu1, MAO Shi-feng1, ZHAO Deng2, YE Min-you1, 3. Simulation study of the radiative divertor under different gas puffing locations for CFETR[J]. NUCLEAR FUSION AND PLASMA PHYSICS, 2020, 40(4): 336-343.

周一夫1，毛世峰*1，赵登2，叶民友1, 3. CFETR不同位置充气下的辐射偏滤器模拟研究[J]. 核聚变与等离子体物理, 2020, 40(4): 336-343.

References

[1] Wan Y X, Li J G, Liu Y, et al. Overview of the present progress and activities on the CFETR [J]. Nucl. Fusion, 2017, 57(10): 102009.
[2] Xu G L, Zhou Y F, Mao S F. The influence of divertor plasma parameter on tungsten screening in high recycling regime for CFETR [J]. IEEE Transactions on Plasma Science, 2018, 46(5): 1382-1386.
[3] Shi N, Chan V S, Jian X, et al. Study of impurity effects on CFETR steady-state scenario by self-consistent integrated modeling [J]. Nucl. Fusion, 2017, 57(12): 126046.
[4] Schneider R, Bonnin X, Borrass K, et al. Plasma edge physics with B2-EIRENE [J]. Contrib. Plasma Phys. 2006, 46(1?2): 3-191.
[5] Chankin A V, Coster D P, Dux R, et al. SOLPS modelling of ASDEX upgrade H-mode plasma [J]. Plasma Phys. Contr. Fusion, 2006, 48: 839–868.
[6] Maingi R, Boyle D P, Canik J M, et al. The effect of progressively increasing lithium coatings on plasma discharge characteristics, transport, edge profiles and ELM stability in the national spherical torus experiment [J]. Nucl. Fusion, 2012, 52(8): 083001.
[7] Kotov V, Reiter D, Pitts R A, et al. Numerical modelling of high density JET divertor plasma with the SOLPS 4.2 (B2-EIRENE) code [J]. Plasma Phys. Contr. Fusion, 2008, 50(10): 105012.
[8] Sang C F, Stangeby P C, Guo H Y, et al. SOLPS modeling of the effect on plasma detachment of closing the lower divertor in DIII-D [J]. Plasma Phys. Contr. Fusion, 2017, 59(2): 025009.
[9] Sang C F, Du H L, Zuo G Z, et al. SOLPS modeling of lithium transport in the scrape-off layer during real-time lithium injection on EAST [J]. Nucl. Fusion, 2016, 56(10): 106018.
[10] Sang C F, Wang Z H, Xu M, et al. Simulation of the gas puffing fueling on the HL-2A tokamak using SOLPS [J]. Plasma Phys. Contr. Fusion, 2018, 136: 1041-1046.
[11] Kukushkin A S, Pacher H D, Kotov V et al. Finalizing the ITER divertor design: The key role of SOLPS modeling [J]. Fusion Engineering and Design, 2011, 86: 2865–2873.
[12] Stangeby P C, Elder J D. Calculation of observable quantities using a divertor impurity interpretive code, DIVIMP [J]. J. Nucl. Mater. 1992, 196?198: 258-263.
[13] Bernert M, Wischmeier M, Huber A, et al. Power exhaust by SOL and pedestal radiation at ASDEX Upgrade and JET [J]. Nuclear Materials and Energy, 2017, 12: 111- 118.
[14] Wischmeier M, The ASDEX Upgrade team and JET EFDA contributors. High density operation for reactor-relevant power exhaust [J]. J. Nucl. Mater., 2015, 463: 22-29.
[15] Snyder P B, Groebner R J, Leonard A W, et al. Development and validation of a predictive model for the pedestal height [J]. Phys. Plasmas, 2009, 16: 056118.
[16] Snyder P B, Groebner R J, Hughes J W, et al. A first-principles predictive model of the pedestal height and width: development, testing and ITER optimization with the EPED model [J]. Nucl. Fusion, 2011, 51(10): 103016.
[17] Kukushkin A S, Pacher H D, Pacher G W, et al. Scaling laws for edge plasma parameters in ITER from two-dimensional edge modelling [J]. Nucl. Fusion, 2003, 43, 716-723.
[18] 邓伯权. 聚变堆物理——新构思与新技术 [M]. 北京:中国原子能出版社, 2013.
[19] Chung T, Hutchinson I H, Lipschultz B, et al. DIVIMP modeling of impurity flows and screening in Alcator C-Mod [J]. J. Nucl. Mater., 2005, 463: 672-675.
[20] McCracken G M, Granetz R S, Lipschultz B, et al. Screening of recycling and non-recycling impurities in the Alcator C-Mod tokamak [J]. J. Nucl. Mater., 1997, 241?243: 777-781.