TJ-II: Evolution of LCR by HIBP and Probes: Difference between revisions

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== Description of the activity ==
== Description of the activity ==


It is considered that anomalous transport in toroidal magnetic confinement devices (tokamaks and stellarators) has a turbulent nature. Turbulence has a very complicated structure, containing a self-regulating mechanism - Zonal Flow (ZF) - poloidally and toroidally symmetric plasma structures intertwinned with dynamics of turbulent eddies <ref>P.Diamond et al, PPCF 2005(2017)</ref>. The manifestation of a ZF is Long-range correlations (LRC), observed in both the plasma edge by dual probes <ref>Pedrosa et al, NF 2008</ref> and in the plasma core by Dual HIBPs <ref>[Melnikov et al NF 2017]</ref>.
It is considered that anomalous transport in toroidal magnetic confinement devices (tokamaks and stellarators) has a turbulent nature. Turbulence has a very complicated structure, containing a self-regulating mechanism - Zonal Flow (ZF) - poloidally and toroidally symmetric plasma structures intertwinned with dynamics of turbulent eddies <ref>P. Diamond et al, PPCF 2005(2017)</ref>. The manifestation of a ZF is Long-range correlations (LRC), observed in both the plasma edge by dual probes <ref>M. A. Pedrosa et al, NF 2008</ref> and in the plasma core by Dual HIBPs <ref>A. V. Melnikov et al NF 2017</ref>.
The perturbation of plasma density and temperature profiles after Pellet Injection (PI) in ECRH and NBI plasmas, specifically during a Pellet-induced Enhanced Confinement (PIEC) regime in NBI plasma will allow us to follow the evolution of plasma turbulence, LRCs and plasma potential in the transient regime from normal to enhanced confinement and back. Such simultaneous measurements have a strong potential to shed new light on the physical mechanisms of turbulent transport reduction in the case of a PIEC (NBI) compared to density evolution without a confinement enhancement (PI in ECRH).
The perturbation of plasma density and temperature profiles after Pellet Injection (PI) in ECRH and NBI plasmas, specifically during a Pellet-induced Enhanced Confinement (PIEC) regime in NBI plasma will allow us to follow the evolution of plasma turbulence, LRCs and plasma potential in the transient regime from normal to enhanced confinement and back. Such simultaneous measurements have a strong potential to shed new light on the physical mechanisms of turbulent transport reduction in the case of a PIEC (NBI) compared to density evolution without a confinement enhancement (PI in ECRH).


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