Impurity Control Systems for Reactor Experiments

Post, D.; Mattas, R.F.

doi:10.1007/978-1-4757-0067-1_24

Cited by 2 publications

(2 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Two categories of active particle control systems have been installed in tokamaks: poloidal magnetic divertor and mechanical divertor (or limiter). A comparison between the poloidal magnetic divertor and the limiter in the closed configuration (throat limiter) [4,21] has been carried out in [22].…”

Section: Particle Control In Tokamaksmentioning

confidence: 99%

Particle control systems at the edge of RFP experiments

Sonato¹,

Antoni²,

Carraro³

et al. 2002

Plasma Phys. Control. Fusion

View full text Add to dashboard Cite

Plasma performance in reversed field pinch (RFP) devices, as in the tokamak, is strongly affected by neutrals at the edge. So far only a few experiments have been dedicated to an active control of the neutral particle using conventional solutions of axisymmetric magnetic divertors or throat limiters. The alternative 'vented pump limiter' concept is more attractive for an RFP experiment due to the edge plasma and confinement properties of this magnetic configuration. In this paper, the application of a vented pump limiter to an RFP is discussed and the prototype module of the vented pump limiter designed for the RFX experiment is presented. Finally, the optimization of this concept for a next step RFP device is presented.

show abstract

Section: Particle Control In Tokamaksmentioning

confidence: 99%

Particle control systems at the edge of RFP experiments

Sonato¹,

Antoni²,

Carraro³

et al. 2002

Plasma Phys. Control. Fusion

View full text Add to dashboard Cite

show abstract

“…An important development of the tokamak (and stellarator) concept was the introduction of the magnetic divertor configuration as a means to localize and control plasma-surface interactions [4]. It is now considered that any future magnetic fusion reactor device (either tokamak or stellarator) will most likely take advantage of the divertor concept [5]. Thus the study of neutral particle dynamics in a tokamak divertor is an important issue of fusion research.…”

Section: Plasma-wall Interactionsmentioning

confidence: 99%

Neutral particle dynamics in the Alcator C-Mod tokamak

Niemczewski

1995

View full text Add to dashboard Cite

This thesis presents an experimental study of neutral particle dynamics in Alcator C-Mod -a high power-and particle-density tokamak with an advanced poloidal divertor. The primary diagnostic used in the study is a set of six neutral pressure gauges, including special-purpose gauges built for in situ tokamak operation.While a low main chamber neutral pressure coincides with high plasma confinement regimes, a high divertor pressure is required for heat and particle flux dispersion in future devices such as ITER. Thus we examine conditions that optimize divertor compression, defined here as a divertor-to-midplane pressure ratio. We find that both pressures depend primarily on the edge plasma regimes defined by the scrape-off-layer heat transport. While the maximum divertor pressure (pdiv =30-60 mTorr) is achieved at high core plasma densities ( Ke =2-4.1 020 m-3), corresponding to the detached divertor state, the maximum compression (-70) is achieved in the high-recycling regime. Variations in the divertor geometry have a weaker effect on the neutral pressures. For otherwise similar plasmas the divertor pressure and compression are maximized when the strike point is located at the bottom of the vertical target plate.We introduce a simple flux balance model, which allows us to explain the divertor neutral pressure across a range of plasma densities. In particular, a high pressure sustained in the detached divertor (despite a considerable drop in the recycling -3-source) can be explained by scattering of neutrals off the cold plasma plugging the divertor throat. Because neutrals are confined in the divertor through scattering and ionization processes (provided the mean-free-paths are much shorter than a typical escape distance) tight mechanical baffling is unnecessary. The analysis suggests that two simple structural modifications may increase the divertor compression in Alcator C-Mod by a factor of -5. Widening the divertor throat would increase the divertor recycling source, while closing leaks in the divertor structure would eliminate a significant neutral loss mechanism.

show abstract

Impurity Control Systems for Reactor Experiments

Cited by 2 publications

References 41 publications

Particle control systems at the edge of RFP experiments

Particle control systems at the edge of RFP experiments

Neutral particle dynamics in the Alcator C-Mod tokamak

Contact Info

Product

Resources

About