Beam transmission dependence on beam parameters for TJ-II Neutral Beam Injectors

Liniers, M.; Damba, J.; Guasp, J.; Sebastián, J.A.; Martín, Fernando; Rojo, B.; Carrasco, R. C.; Sánchez, E.; Miguel, Francisco Javier Tamayo de; Wolfers, G.; Soleto, A.; Ascasíbar, E.

doi:10.1016/j.fusengdes.2017.05.104

Cited by 15 publications

(8 citation statements)

References 7 publications

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“…Higher density plasmas are achieved using neutral beam injection (NBI) heating. Two injectors, one co- and one counter-, are in operation delivering a port-through power per injector up to 700 kW [15]. The flexibility of TJ-II offers the possibility to explore a wide rotational transform range in low, negative magnetic shear configurations.…”

Section: Tj-ii Properties Diagnostic Capabilities and Advanced Analys...mentioning

confidence: 99%

H-mode transition in the TJ-II stellarator plasmas

Estrada¹,

Hidalgo²

2023

Phil. Trans. R. Soc. A.

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Since the first H-mode transitions were observed in TJ-II plasmas in 2008, an extensive experimental effort has been done aiming at better physics understanding of confinement transitions. In this article, an overview of the main findings related to the L-H transition in TJ-II is presented including how the radial electric field is driven, what are the possible mechanisms for turbulence suppression and what are the related temporal and spatial scales that can impact the transition. The trigger of the L-H transition in TJ-II plasmas is found to be more correlated with the development of fluctuating E × B flows than with steady-state E r effects, pointing to the role played by zonal flows in mediating the transition. Experimental evidence supporting the predator–prey relationship between turbulence and flows as the basis for the L-H transition, found for the first time in TJ-II, reinforces this conclusion. Besides, the reduction in the turbulent transport at the transition is detected at the barrier region but also in a wider radial range with weak or even zero E × B flow shear, which points to other mechanisms beyond the turbulence suppression by local sheared flows. This article is part of a discussion meeting issue ‘H-mode transition and pedestal studies in fusion plasmas’.

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Section: Tj-ii Properties Diagnostic Capabilities and Advanced Analys...mentioning

confidence: 99%

H-mode transition in the TJ-II stellarator plasmas

Estrada¹,

Hidalgo²

2023

Phil. Trans. R. Soc. A.

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“…Figure 3b shows an IR image of the TC after a beam pulse, taken with the new IR system. The dark spots on the TC vertical center-line are two copper buttons for independent temperature measurements, while the three smaller Cu buttons are for spatial reference [7].…”

Section: Regions Of Interest (Roi's)mentioning

confidence: 99%

“…Until recently IR cameras with bolometric detectors have been used at TJ-II to monitor beamwall interaction during NBI pulses [6] and to measure beam power profiles using the thermal print of the beams on a Target Calorimeter [7]. In both applications high spatial or temporal resolutions are not required, so IR cameras with bolometer array detectors were sufficient to fulfill the requirements.…”

Section: Introductionmentioning

confidence: 99%

New infrared imaging diagnostic for the Neutral Beam Heating System at the TJ-II stellarator

et al. 2019

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“…A negative beam source based neutral beam injector (NNBI) with beam energy of 200-400 keV, beam power of 2 MW and beam duration of 100 s is one of the devices. In order to obtain high power and long pulse beam with high quality, it is necessary to measure the beam profile in real time [6,7]. At present, a calorimeter with double-layer copper tubes is employed for beam dump.…”

Section: Introductionmentioning

confidence: 99%

Preliminary experimental results of tungsten wire calorimeter for CRAFT NNBI

Yu,

Xu,

et al. 2024

J. Inst.

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The comprehensive Research Facility for Fusion Technology(CRAFT) has been carried out since 2019 in China and as an important component of CRAFT, a negative ion-based neutral beam injection sysgem(NNBI) (200–400 keV, 2 MW) is under construction. In order to realize online diagnosis of beam uniformity, a tungsten wire calorimeter is developed. The tungsten wire calorimeter is characterized by double-layer tungsten wire mesh structure. During beam bombardment, the tungsten wire mesh is heated and emits light, a visible light camera is used to photograph the tungsten wire calorimeter. The beam profile is obtained by digitizing the light intensity distribution map. In this paper, through the thermal simulation anslysis of tungsten wire, the installation position of tungsten wire calorimeter are determined and the spatial resolution under different beam divergence are also analyzed.The tungsten wire calorimeter was tested on the beam source test platform, the light intensity distribution maps of the tungsten wire calorimeter under 15 keV–40 keV beam energy were obtained. The work above will accumulate experience for the operation of tungsten wire calorimeter for full scale beam source in the next stage, and provide technical means for the conditioning of negative beam sources.

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Beam transmission dependence on beam parameters for TJ-II Neutral Beam Injectors

Cited by 15 publications

References 7 publications

H-mode transition in the TJ-II stellarator plasmas

H-mode transition in the TJ-II stellarator plasmas

New infrared imaging diagnostic for the Neutral Beam Heating System at the TJ-II stellarator

Preliminary experimental results of tungsten wire calorimeter for CRAFT NNBI

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