Single and double null equilibria in the SMART Tokamak

Doyle, Scott; Mancini, A.; Agredano-Torres, M.; García-Sánchez, Jorge Luis; Segado-Fernández, J.; Ayllon-Guerola, J.; García-Muñoz, M.; Viezzer, E.; Garcı́a-López, J.; Hwang, Y.S.; Chung, Kyoung−Jae

doi:10.1088/2516-1067/ac2a0e

Cited by 4 publications

(5 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Both single-null and double-null configurations can be produced. For more technical details, the interested reader is referred to [14][15][16][17].…”

Section: Smartmentioning

confidence: 99%

“…Finally, to achieve a better understanding of the small A regime and also use more realistic equilibria, we will consider the ST SMART [14][15][16][17]. This is a ST that only very recently started operation at the University of Seville, characterized by strong geometric flexibility, which should enable the creation of single-null and double-null NT and PT configurations.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Physical insights from the aspect ratio dependence of turbulence in negative triangularity plasmas

Balestri,

Ball,

Coda

et al. 2024

Plasma Phys. Control. Fusion

Self Cite

View full text Add to dashboard Cite

In this work, we study the impact of aspect ratio A = R0/r (the ratio of major radius R0 to minor radius r) on the confinement benefits of Negative Triangularity (NT) plasma shaping. We use high-fidelity flux tube gyrokinetic GENE simulations and consider several different scenarios: four of them inspired by TCV experimental data, a scenario inspired by DIII-D experimental data and a scenario expected in the new SMART spherical tokamak. The present study reveals a surprising and non-trivial dependence. NT improves confinement at any value of A for ITG turbulence, while for TEM turbulence confinement is improved only in the case of large and conventional aspect ratios. Additionally, through a detailed study of a large aspect ratio case with pure ITG drive, we develop an intuitive physical picture that explains the beneficial effect of NT at large and conventional aspect ratios. This picture does not hold in TEM-dominated regimes, where a complex synergistic effect of many factors is found. Finally, we performed the first linear gyrokinetic simulations of SMART, finding that both NT and PT scenarios are dominated by micro-tearing-mode (MTM) turbulence and that NT is more susceptible to MTMs at tight aspect ratio. However, we found that a regime where ITGs dominate in SMART can be found, and in this regime NT is more linearly stable.

show abstract

“…Both single-null and double-null configurations can be produced. For more technical details, the interested reader is referred to [14][15][16][17].…”

Section: Smartmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Physical insights from the aspect ratio dependence of turbulence in negative triangularity plasmas

Balestri,

Ball,

Coda

et al. 2024

Plasma Phys. Control. Fusion

Self Cite

View full text Add to dashboard Cite

show abstract

“…Previous simulations in preparation for SMART operations used a combination of codes for magnetic configuration (FIESTA [21]) and transport analysis (ASTRA [22]). The first studies focused on Ohmic L-mode discharges [20]. Next, NBIheated scenarios were considered [10], including scenarios for Phase II for assessment of transition from L-mode to H-mode.…”

Section: Simulation Methodologymentioning

confidence: 99%

“…Three pairs of in-vessel poloidal field (PF) coils complement two out-vessel coils to provide the required flexibility in the achievable magnetic configurations [7,8,20]. According to initial modeling, a triangularity in the range δ = −0.6 → +0.6 can be achieved.…”

Section: The Smart Devicementioning

confidence: 99%

“…As shown in figure 13, it is assumed that the plasma configuration shifts from inner-wall limited shortly after the breakdown phase (not included here) to a diverted configuration during and after the current rampup. The magnetic configurations for the different phases, based on previous work from [20], are used as input for predictive TRANSP simulations.…”

Section: Scenario Evolutionmentioning

confidence: 99%

See 1 more Smart Citation

NBI optimization on SMART and implications for scenario development

Podestà,

Cruz-Zabala,

Poli

et al. 2024

Plasma Phys. Control. Fusion

Self Cite

View full text Add to dashboard Cite

The SMall Aspect Ratio Tokamak (SMART) under commissioning at the University of Seville, Spain, aims to explore confinement properties and possible advantages in confinement for compact/spherical tokamaks operating at negative vs. positive triangularity. This work explores the benefits of auxiliary heating through Neutral Beam Injection (NBI) for SMART scenarios beyond the initial Ohmic phase of operations, in support of the device’s mission. Expected values of electron and ion temperature achievable with NBI heating are first predicted for the current flat-top phase, including modeling to optimize the NBI injection geometry to maximize NBI absorption and minimize losses for a given equilibrium. Simulations are then extended for a selected case to cover the current ramp-up phase. Differences with results obtained for the flat-top phase indicate the importance of determining the plasma evolution over time, as well as self-consistently determining the edge plasma parameters for reliable time-dependent simulations. Initial simulation results indicate the advantage of auxiliary NBI heating to achieve nearly double values of pressure and stored energy compared to Ohmic discharges, thus significantly increasing the device’s performance. The scenarios developed in this work will also contribute to diagnostic development and optimization for SMART, as well as providing test cases for initial predictions of macro- and micro-instabilities.

show abstract