Helium transport in vented divertors and limiters

Abou-Gabal, Hanaa H.; Emmert, G.A.

doi:10.1088/0029-5515/31/3/001

Cited by 18 publications

(11 citation statements)

References 16 publications

(27 reference statements)

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“…Earlier calculations suggested that elastic scattering of helium neutrals by hydrogenic ions could enhance helium atom transport towards the divertor [ 250,251]. Experimental measurements have shown that this process mainly heats the helium atoms in the divertor, thus increasing their mean free path [252].…”

Section: Helium Exhaust and Noble Gas Impurity Enrichmentmentioning

confidence: 99%

Chapter 4: Power and particle control

Loarte¹,

et al. 2007

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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...

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Section: Helium Exhaust and Noble Gas Impurity Enrichmentmentioning

confidence: 99%

Chapter 4: Power and particle control

Loarte¹,

et al. 2007

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show abstract

“…The beryllium concentration is estimated conservatively from JET beryllium limiter experiments [8,9]. Early calculations suggested that elastic scattering of helium neutrals by hydrogenic ions could enhance helium atom transport toward the divertor [10,11]. However, spectroscopic measurements have shown that this process mainly heats the helium atoms in the divertor [12], thus increasing their mean-free-path.…”

Section: Projection Of Iter Performancementioning

confidence: 99%