Tungsten(W)accumulation in the core,depending on W generation and transport in the edge region,is a severe issue in fusion reactors.Compared to standard divertors(SDs),snowflake divertors(SFDs)can effectively suppress...Tungsten(W)accumulation in the core,depending on W generation and transport in the edge region,is a severe issue in fusion reactors.Compared to standard divertors(SDs),snowflake divertors(SFDs)can effectively suppress the heat flux,while the impact of magnetic configurations on W core accumulation remains unclear.In this study,the kinetic code DIVIMP combined with the SOLPS-ITER code is applied to investigate the effects of divertor magnetic configurations(SD versus SFD)on W accumulation during neon injection in HL-3.It is found that the W concentration in the core of the SFD is significantly higher than that of the SD with similar total W erosion flux.The reasons for this are:(1)W impurities in the core of the SFD mainly originate from the inner divertor,which has a short leg,and the source is close to the divertor entrance and upstream separatrix.Furthermore,the W ionization source(S_(W0))is much stronger,especially near the divertor entrance.(2)The region overlap of S_(W0)and F_(W,TOT)pointing upstream promote W accumulation in the core.Moreover,the influence of W source locations at the inner target on W transport in the SFD is investigated.Tungsten impurity in the core is mainly contributed by target erosion in the common flux region(CFR)away from the strike point.This is attributed to the fact that the W source at this location enhances the ionization source above the W ion stagnation point,which sequentially increases W penetration.Therefore,the suppression of far SOL inner target erosion can effectively prevent W impurities from accumulating in the core.展开更多
Simulations of carbon impurity transport in SOL/divertor plasmas with Ohmic heating on EAST tokamak were performed using the two-dimensional（2D）Monte Carlo impurity transport code DIVIMP.The background plasmas for D...Simulations of carbon impurity transport in SOL/divertor plasmas with Ohmic heating on EAST tokamak were performed using the two-dimensional（2D）Monte Carlo impurity transport code DIVIMP.The background plasmas for DIVIMP simulations were externally taken from B2.5/Eirene calculation.Besides the basic output of DIVIMP,the 2D density distributions of the carbon impurity with different ionization states and neutral carbon atoms were obtained,the2D distributions of CII and CIII emissivities from C＋1and C＋2radiation respectively were also calculated.Comparison between the measured and calculated CIII emissivities showed favorable agreement,indicating that the impurity physics transport models,as implemented in the DIVIMP code,are suitable for the EAST tokamak plasma condition.展开更多
由于低质量数材料不可接受的高腐蚀率以及氚共沉积的问题,未来聚变堆中更希望使用全钨壁。由于钨在芯部的高辐射冷却率,芯部的钨杂质浓度需要限制在非常低的水平(约10^(-5))。中国聚变工程试验堆(China Fusion Engineering Test Reactor...由于低质量数材料不可接受的高腐蚀率以及氚共沉积的问题,未来聚变堆中更希望使用全钨壁。由于钨在芯部的高辐射冷却率,芯部的钨杂质浓度需要限制在非常低的水平(约10^(-5))。中国聚变工程试验堆(China Fusion Engineering Test Reactor,CFETR)要求其高功率稳态运行,全钨壁是优先考虑的方案。为了估计全钨壁CFETR的芯部钨杂质浓度,用边界等离子体物理模拟软件SOLPS(Scrape-off Layer Plasma Simulation)对下单零偏滤器位形不同氖气(Ne)辐射杂质注入速率下模拟得到边界等离子体背景,再利用蒙特卡罗杂质输运程序DIVIMP(DIVertor and IMPurity)对钨杂质的输运进行了模拟。当Ne注入速率较低、靶板温度仍然较高时,即使仅考虑靶板为钨材料,芯部钨杂质浓度依然过高。当外靶板峰值温度降低至约10 eV时,钨靶板对芯部钨杂质浓度的贡献降至可接受的水平;但当包含主等离子体室壁的贡献时,芯部钨杂质浓度仍然达到10^(-4)的水平。因此当Ne杂质注入速率较高时,过高的芯部钨杂质浓度主要来源于主等离子体室壁。未来的工作中需要进一步关注钨壁对芯部钨杂质浓度的影响。展开更多
Transport of carbon in the edge plasma of EAST with a heating power Pin of 8 MW is studied using DIVIMP code. The background plasmas for DIVIMP are taken from the results by using B2.5-Eirene code. For different plasm...Transport of carbon in the edge plasma of EAST with a heating power Pin of 8 MW is studied using DIVIMP code. The background plasmas for DIVIMP are taken from the results by using B2.5-Eirene code. For different plasma densities at the core-SOL interface and the different divertor operational regimes, namely low recycling, high recycling and detachment, the simulated results show that the impurity density in SOL is higher for the high recycling regime than that for the low recycling regime, while impurity density in SOL is lower for the detachment regime than that for both the low and high recycling regimes.展开更多
基金supported by National Natural Science Foundation of China(Nos.12235002 and 12122503)National Key R&D Program of China(No.2018YFE0301101)+1 种基金Dalian Science&Technology Talents Program(No.2022RJ11)Xingliao Talent Project(No.XLYC2203182)。
文摘Tungsten(W)accumulation in the core,depending on W generation and transport in the edge region,is a severe issue in fusion reactors.Compared to standard divertors(SDs),snowflake divertors(SFDs)can effectively suppress the heat flux,while the impact of magnetic configurations on W core accumulation remains unclear.In this study,the kinetic code DIVIMP combined with the SOLPS-ITER code is applied to investigate the effects of divertor magnetic configurations(SD versus SFD)on W accumulation during neon injection in HL-3.It is found that the W concentration in the core of the SFD is significantly higher than that of the SD with similar total W erosion flux.The reasons for this are:(1)W impurities in the core of the SFD mainly originate from the inner divertor,which has a short leg,and the source is close to the divertor entrance and upstream separatrix.Furthermore,the W ionization source(S_(W0))is much stronger,especially near the divertor entrance.(2)The region overlap of S_(W0)and F_(W,TOT)pointing upstream promote W accumulation in the core.Moreover,the influence of W source locations at the inner target on W transport in the SFD is investigated.Tungsten impurity in the core is mainly contributed by target erosion in the common flux region(CFR)away from the strike point.This is attributed to the fact that the W source at this location enhances the ionization source above the W ion stagnation point,which sequentially increases W penetration.Therefore,the suppression of far SOL inner target erosion can effectively prevent W impurities from accumulating in the core.
基金supported by National Natural Science Foundation of China(Nos.11261140328,10975158)
文摘Simulations of carbon impurity transport in SOL/divertor plasmas with Ohmic heating on EAST tokamak were performed using the two-dimensional（2D）Monte Carlo impurity transport code DIVIMP.The background plasmas for DIVIMP simulations were externally taken from B2.5/Eirene calculation.Besides the basic output of DIVIMP,the 2D density distributions of the carbon impurity with different ionization states and neutral carbon atoms were obtained,the2D distributions of CII and CIII emissivities from C＋1and C＋2radiation respectively were also calculated.Comparison between the measured and calculated CIII emissivities showed favorable agreement,indicating that the impurity physics transport models,as implemented in the DIVIMP code,are suitable for the EAST tokamak plasma condition.
基金supported by National Natural Science Foundation of China (No.10975158)in part by the National Magnetic Fusion Program of China (No.2009GB106001)
文摘Transport of carbon in the edge plasma of EAST with a heating power Pin of 8 MW is studied using DIVIMP code. The background plasmas for DIVIMP are taken from the results by using B2.5-Eirene code. For different plasma densities at the core-SOL interface and the different divertor operational regimes, namely low recycling, high recycling and detachment, the simulated results show that the impurity density in SOL is higher for the high recycling regime than that for the low recycling regime, while impurity density in SOL is lower for the detachment regime than that for both the low and high recycling regimes.
