Hydrogen cluster-like behaviour during supersonic molecular beam injection on the HL-1M tokamak

Lianghua, Yao; Zhou, Yan; Cao, Jianyong; Feng, B. B.; Feng, Zhaochi; Luo, J.L.; Dong, J.Q.; Yan, L.W.; Hong, W.Y.; Li, Kehua; Cui, Z.Y.; Liu, Yong; Enyao, Wang; Yan, Jing; Team, Hl M

doi:10.1088/0029-5515/41/7/303

Cited by 50 publications

(31 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Main features of SMBI are a higher molecular speed and lower divergence compared to gas puffing (GP). SMBI has been implemented on the HL-1M tokamak [471,472], the HT-7 tokamak [473] and the W7-AS stellarator [474]. A Laval nozzle is utilized to inject a well collimated supersonic jet in the plasma (typically 5 10 19 particles per pulse with an injection time ranging from tens to hundreds of ms [471]).…”

Section: Supersonic Gas Jet and Low Field Side Puffingmentioning

confidence: 99%

Chapter 4: Power and particle control

Loarte¹,

et al. 2007

View full text Add to dashboard Cite

Abstract.Progress, since the ITER Physics Basis publication, in understanding the processes that will determine the properties of the plasma edge and its interaction with material elements in ITER is described. Experimental areas where significant progress has taken place are : energy transport in the SOL in particular of the anomalous transport scaling, particle transport in the SOL that plays a major role in the interaction of diverted plasmas with the main chamber material elements, ELM energy deposition on material elements and the transport mechanism for the ELM energy from the main plasma to the plasma facing components, the physics of plasma detachment and neutral dynamics including the edge density profile structure and the control of plasma particle content and He removal, the erosion of low and high Z materials in fusion devices, their transport to the core plasma and their migration at the plasma edge including the formation of mixed materials, the processes determining the size and location of the retention of tritium in fusion devices and methods to remove it and the processes determining the efficiency of the various fuelling methods as well as their development towards the ITER requirements. This experimental progress has been accompanied by the development of modelling tools for the physical processes at the edge plasma and plasma-materials interaction and the further validation of these models by comparing their predictions with the new experimental results. Progress in the modelling development and validation has been mostly concentrated in the following areas : refinement of the predictions for ITER with plasma edge modelling codes by inclusion of detailed geometrical features of the divertor and the introduction of physical effects, which can play a 2 major role in determining the divertor parameters at the divertor for ITER conditions such as hydrogen radiation transport and neutral-neutral collisions, modelling of the ion orbits at the plasma edge, which can play a role in determining power deposition at the divertor target, models for plasma-materials and plasma dynamics interaction during ELMs and disruptions, models for the transport of impurities at the plasma edge to describe the core contamination by impurities and the migration of eroded materials at the edge plasma and its associated tritium retention and models for the turbulent processes that determine the anomalous transport of energy and particles across the SOL. The implications for the expected performance of the reference regimes in ITER, the operation of the ITER device and the lifetime of the plasma facing materials are discussed. Introduction.This chapter outlines the significant progress achieved since the ITER Physics Basis in understanding basic scrape-off layer (SOL) and divertor processes in a tokamak. The interaction of plasma with first-wall surfaces will have considerable impact on the performance of fusion plasmas, the lifetime of plasma facing components, and the retention of tritium in next step Burning Plasma E...

show abstract

Section: Supersonic Gas Jet and Low Field Side Puffingmentioning

confidence: 99%

Chapter 4: Power and particle control

Loarte¹,

et al. 2007

View full text Add to dashboard Cite

show abstract

“…These techniques include supersonic molecular beam injection (SMBI) [73,136,137], edge electron cyclotron heating (ECH) [73,138,139], lower hybrid heating and/or current drive (LHH, LHCD) [140,141], controlled periodic oscillations of the vertical centroid position (jogs) [73,[142][143][144][145][146], ELM pace-making via periodic MPs [147][148][149][150][151][152][153][154], modification of edge profiles and stability with lithium wall coatings [18,[155][156][157][158][159][160][161][162][163][164][165][166][167], and the use of naturally occurring small ELM regimes [23]. Each of these is described below.…”

Section: Other Elm Control: Active and Naturally Occurringmentioning

confidence: 99%

Physics news on the Internet (based on electronic preprints)

Eroshenko¹

2013

Phys.-Usp.

View full text Add to dashboard Cite

Large edge localized modes (ELMs) typically accompany good H-mode confinement in fusion devices, but can present problems for plasma facing components because of high transient heat loads. Here the range of techniques for ELM control deployed in fusion devices is reviewed. Two strategies in the ITER baseline design are emphasized: rapid ELM triggering and peak heat flux control via pellet injection, and the use of magnetic perturbations to suppress or mitigate ELMs. While both of these techniques are moderately well developed, with reasonable physical bases for projecting to ITER, differing observations between multiple devices are also discussed to highlight the needed community R&D. In addition, recent progress in ELM-free regimes, namely quiescent H-mode, I-mode, and enhanced pedestal H-mode is reviewed, and open questions for extrapolability are discussed. Finally progress and outstanding issues in alternate ELM control techniques are reviewed: supersonic molecular beam injection, edge electron cyclotron heating, lower hybrid heating and/or current drive, controlled periodic jogs of the vertical centroid position, ELM pace-making via periodic magnetic perturbations, ELM elimination with lithium wall conditioning, and naturally occurring small ELM regimes.

show abstract

“…15 As an advanced fueling method for tokamak devices, supersonic molecular beam injection ͑SMBI͒ has successfully been demonstrated in HuanLiu-1M ͑HL-1M͒, Hefei Tokamak-7 ͑HT-7͒, Tore Supra, and HuanLiuqi-2A ͑HL-2A͒. [16][17][18] The experimental results show that a supersonic molecular beam can be injected and penetrate deeply into the plasma center at high gas pressure in a medium size tokamak. In these SMBI experiments some significant phenomena have been observed, such as peaked density profile and improved energy confinement time.…”

Section: Introductionmentioning

confidence: 99%

“…In these SMBI experiments some significant phenomena have been observed, such as peaked density profile and improved energy confinement time. [16][17][18][19][20] Additionally, synergetic ECRH and SMBI experiments have been carried out for the above-mentioned purposes in the HL-2A tokamak.…”

Section: Introductionmentioning

confidence: 99%

Enhanced production of runaway electrons during electron cyclotron resonance heating and in the presence of supersonic molecular beam injection in the HL-2A tokamak

Zhang¹,

Liu²,

Yang³

et al. 2010

Physics of Plasmas

View full text Add to dashboard Cite

In the present paper, it is reported that a large production of runaway electrons has been observed during the flattop phase of electron cyclotron resonance heating ͑ECRH͒ discharges and in the presence of supersonic molecular beam injection ͑SMBI͒ in the HuanLiuqi-2A ͑commonly referred to as HL-2A͒ ͓Q. W. Yang, Nucl. Fusion 47, S635 ͑2007͔͒ tokamak. For the set of discharges carried out in the present experiment, the ranges of ECRH power and plasma electron density are 0.8-1.0 MW and ͑3.0-4.0͒ ϫ 10 19 m −3 , respectively. A large number of superthermal electrons are produced through the avalanche effect ͓A. Lazaros, Phys. Plasmas 8, 1263 ͑2001͔͒ during ECRH. The loop voltage increase due to SMBI gives rise to a decline in the critical runaway energy, which leads to that many superthermal electrons could be converted into runaway region. Therefore, this phenomenon may come from the synergetic effects of ECRH and SMBI. That is, the superthermal electrons created by ECRH are accelerated into runaway regime via the Dreicer process which is triggered by SMBI. The experimental results are in well agreement with the calculational ones based on the superthermal electron avalanche effect and the Dreicer runaway theory.

show abstract

Hydrogen cluster-like behaviour during supersonic molecular beam injection on the HL-1M tokamak

Cited by 50 publications

References 11 publications

Chapter 4: Power and particle control

Chapter 4: Power and particle control

Physics news on the Internet (based on electronic preprints)

Enhanced production of runaway electrons during electron cyclotron resonance heating and in the presence of supersonic molecular beam injection in the HL-2A tokamak

Contact Info

Product

Resources

About