Investigations on the heat flux and impurity for the HL-2M divertor

Zheng, Guoyao; Cai, Lijun; Duan, Xuru; Xu, X. Q.; Ryutov, D. D.; Liu, X.; Li, J.X.; Pan, Yuwei

doi:10.1088/0029-5515/56/12/126013

Cited by 21 publications

(13 citation statements)

References 14 publications

(15 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It should be noted that strictly speaking the SF-magnetic configuration we used should be identified as XD according to reference [48] due to the secondary X-point being located outside the plasma domain. However, a similar configuration has been named SF in HL-2M [46,49], NSTX [50,51] as well as DIII-D [17], therefore, we still keep naming it as 'SFD', which is consistent with previous works. Nevertheless, the naming of the configuration does not influence the conclusions.…”

Section: Introductionsupporting

confidence: 77%

“…HL-2M [46] is a copper-conductor tokamak with the major radius R = 1.78 m, minor radius a = 0.6 m, elongation κ > 1.8, plasma current I p = 2 MA, toroidal field B t = 2.2 T. It obtained its first plasma at the end of 2020. One of the most critical superiorities of HL-2M is the capacity to create flexible advanced divertor magnetic configurations, such as SFD magnetic field configuration [47].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Modeling of the effects of impurity seeding on plasma detachment and impurity screening of snowflake divertor on HL-2M tokamak by SOLPS-ITER

Zhang¹,

Sang²,

Li³

et al. 2022

Nucl. Fusion

View full text Add to dashboard Cite

To address the issues of mitigation and control of the heat loads on the divertor target, snowflake divertor (SFD) has been proposed on HL-2M tokamak. In this work, simulations have been performed by using SOLPS-ITER to demonstrate the advantages of SFD on HL-2M on plasma detachment and impurity screening during impurity seeding. Firstly, neon (Ne) and argon (Ar) seeding are chosen for comparison in SFD. It is found that Ar seeding significantly mitigates the in-out asymmetry compared with Ne seeding, mainly in high seeding rate cases. The impurity screening capabilities with Ar seeding are conspicuously better than that of Ne seeding. Subsequently, the SFD and standard divertor (SD) with Ar seeding are compared. The SFD achieves plasma detachment with a seeding rate of more than one order of magnitude lower and has better impurity screening capability than those of the SD. These can be explained by more substantial Ar accumulation in the private flux region near the X-point in SD. Moreover, the simulation shows that D2 puffing near the OMP can drive more Ar ions to the divertor and promote the plasma detachment and impurity screening. Finally, the effects of E×B drift on SFD are studied. It is found that with E×B drift more Ar particles accumulate in the vicinity of both inner and outer targets, especially in the far-SOL region, thus raising the far-SOL power radiation. However, the peak heat flux is mainly located near the separatrix, therefore higher seeding rate is required to achieve detachment. Moreover, the E×B drift drives more Ar particles away from the core region. In addition, the role of molecules on the plasma momentum loss during detachment is analyzed.

show abstract

Section: Introductionsupporting

confidence: 77%

Section: Introductionmentioning

confidence: 99%

Modeling of the effects of impurity seeding on plasma detachment and impurity screening of snowflake divertor on HL-2M tokamak by SOLPS-ITER

Zhang¹,

Sang²,

Li³

et al. 2022

Nucl. Fusion

View full text Add to dashboard Cite

show abstract

“…(a) Tests and qualification of various advanced divertor concepts, such as snowflake (SF) and tripod [49,50], on both physics and technological aspects; (b) Tests and validation of high heat flux plasma-facing components; (c) Investigation of burning plasma physics and design of scenarios compatible with advanced divertor configurations.…”

Section: The Tokamak Hl-2mmentioning

confidence: 99%

“…The combination of the flexible magnet coil system and the open structure divertor, allows HL-2M to test and qualify in various advanced divertor concepts, such as the SF and the tripod configurations. An example of some single-null divertor configurations foreseen in HL-2M is shown in figure 17 with elongation κ = 1.6-1.8 and minor radius a ∼ 0.65 m. The second X-points of the two configurations are designed to be above and below the target plate to form a large wetted area and a longer connection length, toward divertor heat and particle flux control [49,50].…”

Section: Magnet Coil System and Divertor Configurationsmentioning

confidence: 99%

Progress of HL-2A experiments and HL-2M program

Duan¹,

Xu²,

Zhong³

et al. 2022

Nucl. Fusion

Self Cite

View full text Add to dashboard Cite

Since the last IAEA Fusion Energy Conference in 2018, significant progress of the experimental program of HL-2A has been achieved on developing advanced plasma physics, edge localized mode (ELM) control physics and technology. Optimization of plasma confinement has been performed. In particular, high-N H-mode plasmas exhibiting an internal transport barrier have been obtained (normalized plasma pressure N reached up to 3). Injection of impurity improved the plasma confinement. ELM control using resonance magnetic perturbation (RMP) or impurity injection has been achieved in a wide parameter regime, including Types I and III. In addition, the impurity seeding with supersonic molecular beam injection (SMBI) or laser blow-off (LBO) techniques has been successfully applied to actively control the plasma confinement and instabilities, as well as the plasma disruption with the aid of disruption prediction. Disruption prediction algorithms based on deep learning are developed. A prediction accuracy of 96.8% can be reached by assembling convolutional neural network (CNN). Furthermore, transport resulted from a wide variety of phenomena such as energetic particles and magnetic islands have been investigated. In parallel with the HL-2A experiments, the HL-2M mega-ampere class tokamak was commissioned in 2020 with its first plasma. Key features and capabilities of HL-2M are briefly presented.

show abstract

“…Impurity seeding is likely to be required for dissipation of the high values of power flux both for SN [5] and alternative configurations [12]. Impurity seeding increases the effective ion charge Z eff , which, in turn, has an effect on the flat-top duration.…”

Section: Alternative Plasma Configurationsmentioning

confidence: 99%

Plasma Scenarios for the DTT Tokamak with Optimized Poloidal Field Coil Current Waveforms

et al. 2022

View full text Add to dashboard Cite

In the field of nuclear fusion, the power exhaust problem is still an open issue and represents one of the biggest problems for the realization of a commercial fusion power plant. According to the “European Fusion Roadmap”, a dedicated facility able to investigate possible solutions to heat exhaust is mandatory. For this purpose, the mission of the Divertor Tokamak Test (DTT) tokamak is the study of different solutions for the divertor. This paper presents the plasma scenarios for standard and alternative configurations in DTT. The Single Null scenario is described in detail. The alternative configurations are also presented, showing the good flexibility of the machine.

show abstract

Investigations on the heat flux and impurity for the HL-2M divertor

Cited by 21 publications

References 14 publications

Modeling of the effects of impurity seeding on plasma detachment and impurity screening of snowflake divertor on HL-2M tokamak by SOLPS-ITER

Modeling of the effects of impurity seeding on plasma detachment and impurity screening of snowflake divertor on HL-2M tokamak by SOLPS-ITER

Progress of HL-2A experiments and HL-2M program

Plasma Scenarios for the DTT Tokamak with Optimized Poloidal Field Coil Current Waveforms

Contact Info

Product

Resources

About