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TJ-II: Validation of neutral beam current drive: Difference between revisions
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TJ-II: Validation of neutral beam current drive (view source)
Revision as of 16:31, 21 January 2022
, 21 January 2022→Name and affiliation of proponent
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== Name and affiliation of proponent == | == Name and affiliation of proponent == | ||
A. Cappa, S. Mulas, M. Liniers, T. Estrada, E. Ascasibar, J. Velasco et al. | A. Cappa, S. Mulas, M. Liniers, T. Estrada, E. Ascasibar, J. Velasco, K. McCarthy et al. | ||
== Details of contact person at LNF == | == Details of contact person at LNF == | ||
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density control purposes. Plasmas with co-NBI (NBI1) and counter-NBI (NBI2), as well as plasmas with balanced injection (NBI1+NBI2), will be explored. The level of optimum ECRH power will be determined depending | density control purposes. Plasmas with co-NBI (NBI1) and counter-NBI (NBI2), as well as plasmas with balanced injection (NBI1+NBI2), will be explored. The level of optimum ECRH power will be determined depending | ||
on the operation conditions considering that moderate electron temperature (below 800 keV) are desirable to favour shorter stabilization times. Using off-axis ECRH injection may also help to reduce L/R time. | on the operation conditions considering that moderate electron temperature (below 800 keV) are desirable to favour shorter stabilization times. Using off-axis ECRH injection may also help to reduce L/R time. | ||
The measured toroidal current will be compared to the computational/numerical estimates of the toroidal current generated by both neutrals beams. | |||
However, since both bootstrap and NBCD are contributing to the toroidal plasma current, the validation of NBCD needs first a numerical computation of the bootstrap contribution, ideally with a validated tool. | |||
issue in TJ-II ECRH plasmas. Experimental proposals devoted to this task | Validating bootstrap current is a long standing issue in TJ-II ECRH plasmas. Experimental proposals devoted to this task have been unsuccessful because of the difficulties encountered to achieve pulses long enough to observe current stabilization. Two days are requested to carry out this proposal. In its first part, and following the procedure described in http://fusionwiki.ciemat.es/wiki/TJ-II:Validation_of_bootstrap_predictions (Velasco et al.), we will | ||
carry out an attempt to achieve long ECRH pulses, looking for a current stabilization phase, in order to fulfill as best as possible the goals detailed in the proposal by Velasco et al. If proved unfeasible, we will switch to NBI plasmas and carry out the rest of the experiments. | |||
== International or National funding project or entity == | == International or National funding project or entity == | ||
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Required resources: | Required resources: | ||
* Number of plasma discharges or days of operation: | * Number of plasma discharges or days of operation: 2 days. | ||
* Essential diagnostic systems: Rogowski (Ip), Microwave Interferometer, Scattering Thomson (ne & Te), Doppler Reflectometry (Er), ECE (Te), NPA (Ti), MSE (rotational transform) | * Essential diagnostic systems: Rogowski (Ip), Microwave Interferometer, Scattering Thomson (ne & Te), Doppler Reflectometry (Er), ECE (Te), NPA (Ti), MSE (rotational transform) | ||
* Type of plasmas (heating configuration): NBI plasmas with background ECRH power for density control purposes | * Type of plasmas (heating configuration): NBI plasmas with background ECRH power for density control purposes | ||