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== Description of the project == | == Description of the project == | ||
The | The goal of this project, which falls within the realm of magnetic confinement nuclear fusion, is to continue research initiated in projects ENE2013-48679-R and FIS2017-89326-R on fuelling and impurity control of plasmas in the stellarators TJ-II (Ciemat, Madrid) and W7-X (Greifswald, Germany). Further research to resolve these issues is critical to demonstrate steady-state operation of helical-type fusion reactors. Thus it will contribute to the development and scientific exploitation of stellarators, a priority highlighted in the document "Fusion Electricity: a roadmap to the realization of fusion energy" (EFDA 2012). | ||
The first goal is to investigate some aspects of plasma fuelling that are still not fully understood (influence of fast electrons, magnetic configuration, and heating method on pellet ablation and deposition) as well as the effects of fuel pellets on plasma turbulence and magnetic activity. For this, the medium-sized heliac TJ-II will be used. It is equipped with a cryogenic pellet injector (PI) for fuelling with solid hydrogen. During previous projects it was found that fuelling efficiency is less that 30% for pellets reaching the centre but increases when fast electrons are present. In this project, it is intended to evaluate fuelling efficiency across a broad range of magnetic configurations and to explore some unexpected ablation phenomena observed in TJ-II, e.g. transitory increases in plasma core electron and ion temperatures and cold wave propogation ahead of injected pellets. While TJ-II is equipped with a large number of modern diagnostics, it is proposed to develop a new filterscope-based system to measure pellet cloud density and temperature to extend knowledge of pellet physics. | The first goal is to investigate some aspects of plasma fuelling that are still not fully understood (influence of fast electrons, magnetic configuration, and heating method on pellet ablation and deposition) as well as the effects of fuel pellets on plasma turbulence and magnetic activity. For this, the medium-sized heliac TJ-II will be used. It is equipped with a cryogenic pellet injector (PI) for fuelling with solid hydrogen. During previous projects it was found that fuelling efficiency is less that 30% for pellets reaching the centre but increases when fast electrons are present. In this project, it is intended to evaluate fuelling efficiency across a broad range of magnetic configurations and to explore some unexpected ablation phenomena observed in TJ-II, e.g. transitory increases in plasma core electron and ion temperatures and cold wave propogation ahead of injected pellets. While TJ-II is equipped with a large number of modern diagnostics, it is proposed to develop a new filterscope-based system to measure pellet cloud density and temperature to extend knowledge of pellet physics. | ||
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== References == | == References == | ||
<references /> | <references /> |
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