Plasma Physics and Controlled Fusion最新文献

{"title":"On the upper bound of non-thermal fusion reactivity with fixed total energy","authors":"Huasheng Xie and Xueyun Wang","doi":"10.1088/1361-6587/ad3f4b","DOIUrl":"https://doi.org/10.1088/1361-6587/ad3f4b","url":null,"abstract":"Fusion reactivity represents the integration of fusion cross-sections and the velocity distributions of two reactants. In this study, we investigate the upper bound of fusion reactivity for a non-thermal reactant coexisting with a thermal Maxwellian background reactant while maintaining a constant total energy. Our optimization approach involves fine-tuning the velocity distribution of the non-thermal reactant. We employ both Lagrange multiplier and Monte Carlo methods to analyze Deuterium–Tritium (D–T) and proton-Boron11 (p-B11) fusion scenarios. Our findings demonstrate that, within the relevant range of fusion energy, the maximum fusion reactivity can often surpass that of the conventional Maxwellian–Maxwellian reactants case by a substantial margin, ranging from 50% to 300%. These enhancements are accompanied by distinctive distribution functions for the non-thermal reactant, characterized by one or multiple beams. These results not only establish an upper limit for fusion reactivity but also provide valuable insights into augmenting fusion reactivity through non-thermal fusion, which holds particular significance in the realm of fusion energy research.","PeriodicalId":20239,"journal":{"name":"Plasma Physics and Controlled Fusion","volume":"314 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140804020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Neural networks for turbulent transport prediction in a simplified model of tokamak plasmas","authors":"L M Pomârjanschi","doi":"10.1088/1361-6587/ad3eb0","DOIUrl":"https://doi.org/10.1088/1361-6587/ad3eb0","url":null,"abstract":"The method of using neural networks (NNs) for turbulent transport prediction in a simplified model of tokamak plasmas is explored. The NNs are trained on a database obtained via test-particle simulations of a transport model in the slab-geometrical approximation. It consists of a five-dimensional input of transport model parameters, and the radial diffusion coefficient as output. The NNs display fast and efficient convergence, a validation error below 2 , and predictions in excellent agreement with the real data, obtained orders of magnitude faster than test-particle simulations. In comparison to a spline interpolation, the NN outperforms, exhibiting better predicting and extrapolating capabilities. We demonstrate the preciseness and efficiency of this method as a proof-of-concept, establishing a promising approach for future, more comprehensive research on the use of NNs for transport predictions in tokamak plasmas.","PeriodicalId":20239,"journal":{"name":"Plasma Physics and Controlled Fusion","volume":"16 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140804019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modelling of power exhaust in TCV positive and negative triangularity L-mode plasmas","authors":"E Tonello, F Mombelli, O Février, G Alberti, T Bolzonella, G Durr-Legoupil-Nicoud, S Gorno, H Reimerdes, C Theiler, N Vianello, M Passoni, the TCV Team and the WPTE Team","doi":"10.1088/1361-6587/ad3c19","DOIUrl":"https://doi.org/10.1088/1361-6587/ad3c19","url":null,"abstract":"L-mode negative triangularity (NT) operation is a promising alternative to the positive triangularity (PT) H-mode as a high-confinement edge localised mode-free operational regime. In this work, two TCV Ohmic L-mode core density ramps with opposite triangularity are investigated using SOLPS-ITER modelling. This numerical study aims to investigate the power exhaust differences between NT and PT focusing, in particular, on the geometrical effect of triangularity. To disentangle the latter from differences related to cross-field transport, anomalous diffusivities for particle ( ) and energy ( ) transport are fixed to the same values in PT and NT. The simulation results clearly show dissimilar transport and accumulation of neutral particles in the scrape-off layer for the two configurations. This gives rise to different ionization sources in the edge and divertor regions and produces differences in the poloidal and cross-field fluxes, ultimately leading to different power and particle divertor fluxes in the two configurations. Simulations recover the experimental feature of a hotter and attached outer target ( ) in the NT scenario compared to the PT counterpart.","PeriodicalId":20239,"journal":{"name":"Plasma Physics and Controlled Fusion","volume":"1 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140804035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of increasing plasma-wall gap on plasma response to RMP fields in ITER","authors":"X Bai, A Loarte, Y Q Liu, S D Pinches, F Koechl, L Li, M Dubrov, Y Gribov","doi":"10.1088/1361-6587/ad3aa0","DOIUrl":"https://doi.org/10.1088/1361-6587/ad3aa0","url":null,"abstract":"The impact of increasing plasma-wall gap on controlling edge-localized modes (ELMs) is numerically evaluated for the ITER 5 MA/2.65 T H-mode scenarios with full tungsten wall, based on the MARS-F computed plasma response to the applied <italic toggle=\"yes\">n</italic>= 3–5 (<italic toggle=\"yes\">n</italic> is the toroidal mode number) resonant magnetic perturbation (RMP) fields. Three new scenarios, referred to as standard, clearance and outergap, are considered assuming different plasma-wall gap sizes over a range on which vertically stability can be maintained by in-vessel coils in ITER. The latter are shown to have both direct and indirect effects on the plasma response and hence ELM control in ITER. The indirect and also primary influence occurs via change of the equilibrium edge safety factor <italic toggle=\"yes\">q₉₅\u0000</italic>, which decreases with increasing the plasma-wall gap (at fixed plasma current and toroidal field), leading to a multi-peaking structure in the plasma response as measured by the plasma displacement near the X-point or the edge-localized resonant radial magnetic field perturbation. The direct, albeit secondary effect, is the reduction of local peak amplitudes with increasing the plasma-wall gap thus weakening the RMP field efficiency for ELM control with a given current in the control coils. A slight reduction of the plasma current, from 5 MA to 4.77, 4.92 and 4.65 MA for the standard, clearance and outergap scenarios, respectively, is found to be sufficient to access the <italic toggle=\"yes\">q</italic>\u0000₉₅ window for the best ELM control with the <italic toggle=\"yes\">n</italic>= 3 RMP. The <italic toggle=\"yes\">n</italic>= 4 coil current configuration with the <italic toggle=\"yes\">n</italic>= 5 sideband is also found favorable for ELM control in ITER, by producing RMP fields with mixed toroidal spectra compared to <italic toggle=\"yes\">n</italic> = 3.","PeriodicalId":20239,"journal":{"name":"Plasma Physics and Controlled Fusion","volume":"221 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140611265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Decoupled magnetic control of spherical tokamak divertors via vacuum harmonic constraints","authors":"O P Bardsley, J L Baker, C Vincent","doi":"10.1088/1361-6587/ad319d","DOIUrl":"https://doi.org/10.1088/1361-6587/ad319d","url":null,"abstract":"Power exhaust is a critical challenge for spherical tokamak reactors, making the design, optimisation and control of advanced divertor configurations crucial. These tasks are greatly simplified if the poloidal magnetic fields in the core and divertor regions can be varied independently. We present a novel method which facilitates decoupling of the core plasma equilibrium from the divertor geometry optimisation and control, using vacuum spherical harmonic (SH) constraints. This has the advantage that it avoids iterative solution of the Grad–Shafranov equation, making it easy to use, rapid and reliable. By comparing a large number of MAST-U equilibrium reconstructions against their approximations using SHs, a small number (<inline-formula>\u0000<tex-math><?CDATA ${sim}4$?></tex-math>\u0000<mml:math overflow=\"scroll\"><mml:mrow><mml:mrow><mml:mo>∼</mml:mo></mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:math>\u0000<inline-graphic xlink:href=\"ppcfad319dieqn1.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>) of harmonics is found to be sufficient to closely reproduce the plasma boundary shape. We show experimentally that poloidal field changes designed to leave harmonics unaffected indeed have no effect on the core plasma shape. When augmented with divertor geometry constraints, this approach gives a powerful tool for creating advanced magnetic configurations, and its simplicity brings improvements in speed and robustness when solving coil position optimisation problems. We discuss the clear benefits to real-time feedback control, feed-forward scenario design and coilset optimisation with a view to future reactors.","PeriodicalId":20239,"journal":{"name":"Plasma Physics and Controlled Fusion","volume":"71 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140315289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-machine benchmark of the self-consistent 1D scrape-off layer model DIV1D from stagnation point to target with SOLPS-ITER","authors":"G L Derks, E Westerhof, M van Berkel, J H Jenneskens, J T W Koenders, S Mijin, D Moulton, H Reimerdes, H Wu","doi":"10.1088/1361-6587/ad2e37","DOIUrl":"https://doi.org/10.1088/1361-6587/ad2e37","url":null,"abstract":"This paper extends a 1D dynamic physics-based model of the scrape-off layer (SOL) plasma, DIV1D, to include the core SOL and possibly a second target. The extended model is benchmarked on 1D mapped SOLPS-ITER simulations to find input settings for DIV1D that allow it to describe SOL plasmas from upstream to target—calibrating it on a scenario and device basis. The benchmark shows a quantitative match between DIV1D and 1D mapped SOLPS-ITER profiles for the heat flux, electron temperature, and electron density within roughly 50% on: (1) the Tokamak Configuration Variable (TCV) for a gas puff scan; (2) a single SOLPS-ITER simulation of the Upgraded Mega Ampere Spherical Tokamak; and (3) the Upgraded Axially Symmetric Divertor EXperiment in Garching Tokamak (AUG) for a simultaneous scan in heating power and gas puff. Once calibrated, DIV1D self-consistently describes dependencies of the SOL solution on core fluxes and external neutral gas densities for a density scan on TCV whereas a varying SOL width is used in DIV1D for AUG to match a simultaneous change in power and density. The ability to calibrate DIV1D on a scenario and device basis is enabled by accounting for cross field transport with an effective flux expansion factor and by allowing neutrals to be exchanged between SOL and adjacent domains.","PeriodicalId":20239,"journal":{"name":"Plasma Physics and Controlled Fusion","volume":"44 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140315103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spin-polarized 3He shock waves from a solid-gas composite target at high laser intensities","authors":"L Reichwein, X F Shen, M Büscher, A Pukhov","doi":"10.1088/1361-6587/ad30c0","DOIUrl":"https://doi.org/10.1088/1361-6587/ad30c0","url":null,"abstract":"We investigate collisionless shock acceleration of spin-polarized <inline-formula>\u0000<tex-math><?CDATA ${}^3$?></tex-math>\u0000<mml:math overflow=\"scroll\"><mml:msup><mml:mrow></mml:mrow><mml:mn>3</mml:mn></mml:msup></mml:math>\u0000<inline-graphic xlink:href=\"ppcfad30c0ieqn1.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>He for laser pulses with normalized vector potentials in the range <inline-formula>\u0000<tex-math><?CDATA $a_0 = 100-200$?></tex-math>\u0000<mml:math overflow=\"scroll\"><mml:msub><mml:mi>a</mml:mi><mml:mn>0</mml:mn></mml:msub><mml:mo>=</mml:mo><mml:mn>100</mml:mn><mml:mo>−</mml:mo><mml:mn>200</mml:mn></mml:math>\u0000<inline-graphic xlink:href=\"ppcfad30c0ieqn2.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>. The setup utilized in the 2D-particle-in-cell simulations consists of a solid carbon foil that is placed in front of the main Helium target. The foil is heated by the laser pulse and shields the Helium from the highly oscillating fields. In turn, a shock wave with more homogeneous fields is induced, leading to highly polarized ion beams. We observe that the inclusion of radiation reaction into our simulations leads to a higher beam charge without affecting the polarization degree to a significant extent.","PeriodicalId":20239,"journal":{"name":"Plasma Physics and Controlled Fusion","volume":"9 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140315042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stability analysis of WEST L-mode discharges with improved confinement from boron powder injection","authors":"G Bodner, C Bourdelle, P Manas, A Gallo, K Afonin, A Diallo, R Lunsford, Ph Moreau, A Nagy, F Clairet, C Gil, E Tsitrone, L Vermare, the WEST Team4","doi":"10.1088/1361-6587/ad2c29","DOIUrl":"https://doi.org/10.1088/1361-6587/ad2c29","url":null,"abstract":"WEST L-mode plasmas with dominant electron heating and no core torque source have observed improvements in confinement during boron (B) powder injection. These results are reminiscent of previous powder injection experiments on other devices and gaseous impurity seeding experiments on WEST. During powder injection, the stored energy increased up to 25% due to enhanced ion and electron heat and particle confinement. The improvements in confinement were not indicative of an L-H transition. To identify the dominant mechanisms and the causality chain behind these improvements in confinement, we employ interpretative modeling using METIS, predictive integrated modeling using a high-fidelity plasma simulator (HFPS), and stand-alone gyrokinetic simulations using quasi-linear gyrokinetic code. Interpretative modeling with METIS allowed for the estimation of missing data while maintaining good overall consistency with experiment. These results provided the initial conditions for fully predictive flux driven simulations using the HFPS. From these simulations, quasi-linear gyrokinetic analysis was performed at &lt;inline-formula&gt;\u0000&lt;tex-math&gt;&lt;?CDATA $rho = 0.5$?&gt;&lt;/tex-math&gt;\u0000&lt;mml:math overflow=\"scroll\"&gt;&lt;mml:mi&gt;ρ&lt;/mml:mi&gt;&lt;mml:mo&gt;=&lt;/mml:mo&gt;&lt;mml:mn&gt;0.5&lt;/mml:mn&gt;&lt;/mml:math&gt;\u0000&lt;inline-graphic xlink:href=\"ppcfad2c29ieqn1.gif\" xlink:type=\"simple\"&gt;&lt;/inline-graphic&gt;\u0000&lt;/inline-formula&gt; and &lt;inline-formula&gt;\u0000&lt;tex-math&gt;&lt;?CDATA $rho = 0.65$?&gt;&lt;/tex-math&gt;\u0000&lt;mml:math overflow=\"scroll\"&gt;&lt;mml:mi&gt;ρ&lt;/mml:mi&gt;&lt;mml:mo&gt;=&lt;/mml:mo&gt;&lt;mml:mn&gt;0.65&lt;/mml:mn&gt;&lt;/mml:math&gt;\u0000&lt;inline-graphic xlink:href=\"ppcfad2c29ieqn2.gif\" xlink:type=\"simple\"&gt;&lt;/inline-graphic&gt;\u0000&lt;/inline-formula&gt;. Collisionality was found to be a strong candidate for the turbulence suppression mechanism at &lt;inline-formula&gt;\u0000&lt;tex-math&gt;&lt;?CDATA $rho = 0.5$?&gt;&lt;/tex-math&gt;\u0000&lt;mml:math overflow=\"scroll\"&gt;&lt;mml:mi&gt;ρ&lt;/mml:mi&gt;&lt;mml:mo&gt;=&lt;/mml:mo&gt;&lt;mml:mn&gt;0.5&lt;/mml:mn&gt;&lt;/mml:math&gt;\u0000&lt;inline-graphic xlink:href=\"ppcfad2c29ieqn3.gif\" xlink:type=\"simple\"&gt;&lt;/inline-graphic&gt;\u0000&lt;/inline-formula&gt;, while a combination of collisionality and the &lt;inline-formula&gt;\u0000&lt;tex-math&gt;&lt;?CDATA ${T_e}/{T_{text{i}}}$?&gt;&lt;/tex-math&gt;\u0000&lt;mml:math overflow=\"scroll\"&gt;&lt;mml:mrow&gt;&lt;mml:msub&gt;&lt;mml:mi&gt;T&lt;/mml:mi&gt;&lt;mml:mi&gt;e&lt;/mml:mi&gt;&lt;/mml:msub&gt;&lt;/mml:mrow&gt;&lt;mml:mrow&gt;&lt;mml:mo&gt;/&lt;/mml:mo&gt;&lt;/mml:mrow&gt;&lt;mml:mrow&gt;&lt;mml:msub&gt;&lt;mml:mi&gt;T&lt;/mml:mi&gt;&lt;mml:mrow&gt;&lt;mml:mtext&gt;i&lt;/mml:mtext&gt;&lt;/mml:mrow&gt;&lt;/mml:msub&gt;&lt;/mml:mrow&gt;&lt;/mml:math&gt;\u0000&lt;inline-graphic xlink:href=\"ppcfad2c29ieqn4.gif\" xlink:type=\"simple\"&gt;&lt;/inline-graphic&gt;\u0000&lt;/inline-formula&gt; ratio was found to be the likely mechanism at &lt;inline-formula&gt;\u0000&lt;tex-math&gt;&lt;?CDATA $rho = 0.65$?&gt;&lt;/tex-math&gt;\u0000&lt;mml:math overflow=\"scroll\"&gt;&lt;mml:mi&gt;ρ&lt;/mml:mi&gt;&lt;mml:mo&gt;=&lt;/mml:mo&gt;&lt;mml:mn&gt;0.65&lt;/mml:mn&gt;&lt;/mml:math&gt;\u0000&lt;inline-graphic xlink:href=\"ppcfad2c29ieqn5.gif\" xlink:type=\"simple\"&gt;&lt;/inline-graphic&gt;\u0000&lt;/inline-formula&gt;. The results additionally suggested that increased &lt;inline-formula&gt;\u0000&lt;tex-math&gt;&lt;?CDATA ${Z_{{text{eff}}}}$?&gt;&lt;/tex-math&gt;\u0000&lt;mml:math overflow=\"scroll\"&gt;&lt;mml:mrow&gt;&lt;mml:msub&gt;&lt;mml:mi&gt;Z&lt;/mml:mi&gt;&lt;mml:mrow&gt;&lt;mml:mrow&gt;&lt;","PeriodicalId":20239,"journal":{"name":"Plasma Physics and Controlled Fusion","volume":"6 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140315207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"NBI optimization on SMART and implications for scenario development","authors":"M Podestà, D J Cruz-Zabala, F M Poli, J Dominguez-Palacios, J W Berkery, M Garcia-Muñoz, E Viezzer, A Mancini, J Segado, L Velarde, S M Kaye","doi":"10.1088/1361-6587/ad2edc","DOIUrl":"https://doi.org/10.1088/1361-6587/ad2edc","url":null,"abstract":"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.","PeriodicalId":20239,"journal":{"name":"Plasma Physics and Controlled Fusion","volume":"152 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140315104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Flow-shear destabilization of multiscale electron turbulence","authors":"E A Belli, J Candy, I Sfiligoi","doi":"10.1088/1361-6587/ad2c28","DOIUrl":"https://doi.org/10.1088/1361-6587/ad2c28","url":null,"abstract":"The impact of sheared <inline-formula>\u0000<tex-math><?CDATA ${mathbf{E} hskip -1pt times hskip -1pt mathbf{B}}$?></tex-math>\u0000<mml:math overflow=\"scroll\"><mml:mrow><mml:mrow><mml:mi mathvariant=\"bold\">E</mml:mi></mml:mrow><mml:mo>×</mml:mo><mml:mrow><mml:mi mathvariant=\"bold\">B</mml:mi></mml:mrow></mml:mrow></mml:math>\u0000<inline-graphic xlink:href=\"ppcfad2c28ieqn1.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> flow on multiscale turbulence is studied with nonlinear gyrokinetic simulations. Simulations are based on DIII-D-like, high-confinement mode (H-mode) pedestal parameters in the regime of low ion temperature gradient drive, where there is a broad spectrum of electron temperature gradient (ETG)-driven turbulence. It is found that <inline-formula>\u0000<tex-math><?CDATA ${mathbf{E} hskip -1pt times hskip -1pt mathbf{B}}$?></tex-math>\u0000<mml:math overflow=\"scroll\"><mml:mrow><mml:mrow><mml:mi mathvariant=\"bold\">E</mml:mi></mml:mrow><mml:mo>×</mml:mo><mml:mrow><mml:mi mathvariant=\"bold\">B</mml:mi></mml:mrow></mml:mrow></mml:math>\u0000<inline-graphic xlink:href=\"ppcfad2c28ieqn2.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> shear can have a significant effect on ETG-driven electron transport, with an unexpected transition from a turbulence stabilization regime at moderate to large shearing rates <italic toggle=\"yes\">γ</italic>\u0000_{\u0000<italic toggle=\"yes\">E</italic>\u0000} to a novel turbulence destabilization regime at low levels of <italic toggle=\"yes\">γ</italic>\u0000_{\u0000<italic toggle=\"yes\">E</italic>\u0000}. In the turbulence stabilization regime, the electron energy flux decreases monotonically with <italic toggle=\"yes\">γ</italic>\u0000_{\u0000<italic toggle=\"yes\">E</italic>\u0000}, even when <italic toggle=\"yes\">γ</italic>\u0000_{\u0000<italic toggle=\"yes\">E</italic>\u0000} is small compared to electron mode growth rates. The stabilizing effect comes dominantly from the electron, not ion, gyrokinetic equation. In the novel destabilization regime, reduction of zonal energy results from the interaction of <italic toggle=\"yes\">γ</italic>\u0000_{\u0000<italic toggle=\"yes\">E</italic>\u0000}-modulated nonlinear drive in the zonal ion gyrokinetic equation, increasing the electron transport over a broad range of shearing rates. Neither of these effects have been observed in previous electron-scale simulations.","PeriodicalId":20239,"journal":{"name":"Plasma Physics and Controlled Fusion","volume":"40 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140315199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}