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Comparison of detachment in Ohmic plasmas with positive and negative triangularity 正三角和负三角欧姆等离子体中脱离现象的比较
IF 2.2 2区 物理与天体物理 Q2 PHYSICS, FLUIDS & PLASMAS Pub Date : 2024-04-21 DOI: 10.1088/1361-6587/ad3c1c
O Février, C K Tsui, G Durr-Legoupil-Nicoud, C Theiler, M Carpita, S Coda, C Colandrea, B P Duval, S Gorno, E Huett, B Linehan, A Perek, L Porte, H Reimerdes, O Sauter, E Tonello, M Zurita, T Bolzonella, F Sciortino, the TCV Team and the EUROfusion Tokamak Exploitation Team
In recent years, negative triangularity (NT) has emerged as a potential high-confinement L-mode reactor solution. In this work, detachment is investigated using core density ramps in lower single null Ohmic L-mode plasmas across a wide range of upper, lower, and average triangularity (the mean of upper and lower triangularity: δ) in the TCV tokamak. It is universally found that detachment is more difficult to access for NT shaping. The outer divertor leg of discharges with could not be cooled to below through core density ramps alone. The behavior of the upstream plasma and geometrical divertor effects (e.g. a reduced connection length with negative lower triangularity) do not fully explain the challenges in detaching NT plasmas. Langmuir probe measurements of the target heat flux widths (λq) were constant to within 30% across an upper triangularity scan, while the spreading factor S was lower by up to 50% for NT, indicating a generally lower integral scrape-off layer width, λint. The line-averaged core density was typically higher for NT discharges for a given fuelling rate, possibly linked to higher particle confinement in NT. Conversely, the divertor neutral pressure and integrated particle fluxes to the targets were typically lower for the same line-averaged density, indicating that NT configurations may be closer to the sheath-limited regime than their PT counterparts, which may explain why NT is more challenging to detach.
近年来,负三角形(NT)已成为一种潜在的高稠度 L 型反应堆解决方案。在这项工作中,我们在 TCV 托卡马克中使用下单空欧姆 L 模式等离子体中的堆芯密度斜坡来研究脱落问题,研究范围包括上三角度、下三角度和平均三角度(上三角度和下三角度的平均值:δ)。人们普遍发现,要对 NT 进行整形,分离是比较困难的。仅通过堆芯密度斜坡无法将放电的外侧分流段冷却到下方。上游等离子体的行为和分流器的几何效应(如负下三角的连接长度缩短)并不能完全解释分离 NT 等离子体所面临的挑战。对目标热通量宽度(λq)的朗缪尔探针测量结果在上三角扫描范围内保持稳定,误差在 30% 以内,而对于 NT 来说,扩展因子 S 降低了 50% 之多,这表明整体刮离层宽度 λint 普遍较低。在给定燃料率的情况下,NT 放电的线平均堆芯密度通常较高,这可能与 NT 中较高的粒子约束有关。与此相反,在相同的线均密度下,转发器中性压力和到达目标的综合粒子通量通常较低,这表明与 PT 相比,NT 配置可能更接近鞘限制机制,这也许可以解释为什么 NT 更难脱离。
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引用次数: 0
Modelling of power exhaust in TCV positive and negative triangularity L-mode plasmas TCV 正三角和负三角 L 型等离子体中的功率排气建模
IF 2.2 2区 物理与天体物理 Q2 PHYSICS, FLUIDS & PLASMAS Pub Date : 2024-04-17 DOI: 10.1088/1361-6587/ad3c19
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
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.
L 模式负三角形(NT)运行是正三角形(PT)H 模式的一种很有前途的替代方案,是一种高引信边缘局部无模式运行机制。在这项工作中,使用 SOLPS-ITER 模型研究了两个具有相反三角形的 TCV 欧姆 L 模式磁芯密度斜坡。这项数值研究旨在调查 NT 和 PT 的功率耗尽差异,尤其侧重于三角形的几何效应。为了将后者与跨场传输的差异区分开来,粒子( )和能量( )传输的反常扩散率在 PT 和 NT 中被固定为相同的值。模拟结果清楚地表明,在两种配置下,中性粒子在刮除层中的传输和积累是不同的。这导致边缘和分流器区域产生不同的电离源,并产生不同的极射和跨场通量,最终导致两种配置中不同的功率和粒子分流器通量。模拟恢复了实验特征,即与 PT 相比,NT 方案中的外部目标( )温度更高,附着力更强。
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引用次数: 0
Radial drift of plasma blobs in a toroidal magnetic field with fully kinetic and reduced fluid models 等离子体球在环形磁场中的径向漂移,采用全动能模型和还原流体模型
IF 2.2 2区 物理与天体物理 Q2 PHYSICS, FLUIDS & PLASMAS Pub Date : 2024-04-16 DOI: 10.1088/1361-6587/ad3c1b
Nathan Mackey, Sergey Blinov, Adam Stanier, Ari Le
In curved magnetic geometries, field-aligned regions of enhanced plasma pressure and density, termed ‘blobs,’ move as coherent filaments across the magnetic field lines. Coherent blobs account for a significant fraction of transport at the edges of magnetic fusion experiments and arise in naturally-occurring space plasmas. This work examines the dynamics of blobs with a fully kinetic electromagnetic particle-in-cell code and with a drift-reduced fluid code. In low-beta regimes with moderate blob speeds, good agreement is found in the maximum blob velocity between the two simulation schemes and simple analytical estimates. The fully kinetic code demonstrates that blob speeds saturate near the initial sound speed, which is a regime outside the validity of the reduced fluid model.
在弯曲的磁场几何结构中,等离子体压力和密度增强的场对齐区域(称为 "小球")会以相干丝状穿过磁场线。在磁核聚变实验边缘的传输中,相干小球占了很大一部分,在自然存在的空间等离子体中也会出现。这项研究利用全动能电磁粒子入胞代码和漂移还原流体代码研究了团块的动力学。在速度适中的低贝塔状态下,两种模拟方案和简单的分析估计值在 Blob 的最大速度上有很好的一致性。全动能代码表明,球速在初始声速附近达到饱和,这超出了还原流体模型的有效范围。
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引用次数: 0
Study on stray electrons ejecting from a long-pulse negative ion source for fusion 关于从用于聚变的长脉冲负离子源射出的杂散电子的研究
IF 2.2 2区 物理与天体物理 Q2 PHYSICS, FLUIDS & PLASMAS Pub Date : 2024-04-16 DOI: 10.1088/1361-6587/ad3c1e
Yuwen Yang, Jianglong Wei, Yuming Gu, Yahong Xie, Chundong Hu
The negative ion based neutral beam injection is a desirable plasma heating and current drive method for the large-scale magnetic fusion devices. Due to the strict requirements and difficult development of the negative ion source for fusion, a long-pulse negative ion source has been developed under the framework of the Comprehensive Research Facility for Fusion Technology in China. This negative ion source consists of a single radio frequency (RF) driver plasma source and a three-electrode accelerator. The typical extraction and acceleration voltage are 4–8 kV and 40–50 kV, respectively. During one shot of the long-pulse (∼100 s) beam extraction, the gas pressure in the vacuum vessel increased sharply and the temperature of the cryopump rise from 8 K to 20 K. Moreover, the vessel wall appeared a high temperature after several long-pulse shots. A self-consistent simulation of beam-gas interaction revealed that the heat loads on the vessel wall should be caused by the stray electrons ejecting from the accelerator. Those stray electrons are mainly generated via the stripping or ionization collisions and strongly deflected by the downstream side of the deflection magnetic field for the co-extracted electron. The location of hot spots measured by infrared thermography is consistent with the simulation results. To solve this problem, a series of electron dumps are designed to avoid the direct impinging of the ejecting electrons on the cryopump and the vessel wall. And the results suggest that the hot spots are almost eliminated.
基于负离子的中性束注入是大型磁核聚变装置理想的等离子体加热和电流驱动方法。由于核聚变对负离子源的严格要求和研制难度,中国在核聚变技术综合研究装置的框架下研制了长脉冲负离子源。该负离子源由一个射频驱动等离子体源和一个三电极加速器组成。典型的萃取电压和加速电压分别为 4-8 千伏和 40-50 千伏。在一次长脉冲(∼100 秒)束流萃取过程中,真空容器中的气体压力急剧上升,低温泵的温度从 8 K 升至 20 K。束气相互作用的自洽模拟显示,容器壁上的热负荷应该是由加速器射出的杂散电子引起的。这些杂散电子主要通过剥离或电离碰撞产生,并被共萃取电子的偏转磁场下游侧强烈偏转。红外热成像测量到的热点位置与模拟结果一致。为了解决这个问题,我们设计了一系列电子甩尾,以避免喷射出的电子直接撞击低温泵和容器壁。结果表明,热点几乎被消除。
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引用次数: 0
Impact of increasing plasma-wall gap on plasma response to RMP fields in ITER 增大等离子体壁间隙对等离子体对热核实验堆 RMP 磁场响应的影响
IF 2.2 2区 物理与天体物理 Q2 PHYSICS, FLUIDS & PLASMAS Pub Date : 2024-04-15 DOI: 10.1088/1361-6587/ad3aa0
X Bai, A Loarte, Y Q Liu, S D Pinches, F Koechl, L Li, M Dubrov, Y Gribov
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 n= 3–5 (n 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 q95, 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 q95 window for the best ELM control with the n= 3 RMP. The n= 4 coil current configuration with the n= 5 sideband is also found favorable for ELM control in ITER, by producing RMP fields with mixed toroidal spectra compared to n = 3.
根据 MARS-F 计算的等离子体对应用 n= 3-5(n 为环形模式数)共振磁扰动(RMP)场的响应,对带有全钨壁的热核实验堆 5 MA/2.65 T H 模式情况下,增大等离子体壁间隙对控制边缘定位模式(ELM)的影响进行了数值评估。考虑了三种新情况,即标准、间隙和外隙,假设等离子体壁间隙大小在一定范围内不同,ITER 的舱内线圈可以在此范围内保持垂直稳定性。结果表明,后者对等离子体响应以及热核实验堆中的 ELM 控制有直接和间接影响。间接影响也是主要影响是通过平衡边缘安全系数 q95 的变化产生的,它随着等离子体壁间隙的增大而减小(在固定等离子体电流和环形磁场条件下),从而导致等离子体响应中的多音结构,该结构可通过 X 点附近的等离子体位移或边缘定位共振径向磁场扰动来测量。直接影响(尽管是次要影响)是随着等离子体壁间隙的增大,局部峰值振幅减小,从而削弱了控制线圈中给定电流下 ELM 控制的 RMP 磁场效率。在标准、间隙和外隙方案中,等离子体电流分别从 5 MA 微降至 4.77、4.92 和 4.65 MA,就足以进入 q95 窗口,实现 n= 3 RMP 的最佳 ELM 控制。与 n=3 相比,n=4 线圈电流配置与 n=5 边带通过产生具有混合环形光谱的 RMP 场,也有利于热核实验堆的 ELM 控制。
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引用次数: 0
Influence of the magnetic configuration on the high-field side scrape-off layer at ASDEX Upgrade and the role of the secondary separatrix 磁配置对 ASDEX 升级版高磁场侧刮除层的影响以及二次分离矩阵的作用
IF 2.2 2区 物理与天体物理 Q2 PHYSICS, FLUIDS & PLASMAS Pub Date : 2024-04-12 DOI: 10.1088/1361-6587/ad3a9f
D Hachmeister, C Silva, J Santos, G D Conway, L Gil, A Silva, U Stroth, J Vicente, E Wolfrum, R M McDermott, R Dux, D Brida, R Fischer, B Kurzan, the ASDEX Upgrade Team4, the EUROfusion MST1 Team5
In tokamaks, radial transport is ballooning, meaning it is enhanced at the low-field side (LFS). This work investigates the effect of the magnetic configuration on the high-field side (HFS) scrape-off layer. Our experiments involved L-mode and H-mode discharges at ASDEX Upgrade, in which we scanned the magnetic configuration from a lower to an upper single-null shape, thus varying the location of the secondary separatrix. We show that the secondary separatrix determines the width of the HFS scrape-off layer, meaning that the density is much lower in the region that is magnetically disconnected from the LFS scrape-off layer, outside the secondary separatrix. Furthermore, we observe that the large density often seen in the HFS divertor drastically decreases as the separation between the primary and secondary separatrices falls below a particular value. This value is different for L-mode and H-mode plasmas and closely matches the power decay length measured at the LFS midplane. We also show how the HFS scrape-off layer density is smaller in an upper single-null than in a lower single-null, when the ionic grad-B drift points down. This difference is likely caused by reversing the E×B drifts in the active divertor when switching the active X-point from the bottom to the top. We further observe that the neutral density in the lower divertor also correlates with the plasma shape and the high-density region in the HFS scrape-off layer. During the shape scans analyzed here, the HFS divertor remained partially detached throughout, with transitory reattachment modulated by ELM activity in H-mode. This work provides novel experimental data that can be leveraged to further the modeling capabilities and understanding of scrape-off layer physics in highly shaped plasmas.
在托卡马克中,径向传输是气球式的,这意味着它在低场侧(LFS)得到增强。这项工作研究了磁配置对高场面(HFS)刮除层的影响。我们的实验涉及在 ASDEX Upgrade 进行的 L 模式和 H 模式放电,在实验中,我们将磁配置从下部单空形状扫描到上部单空形状,从而改变了二次分离矩阵的位置。我们发现二次分离矩阵决定了 HFS 刮离层的宽度,这意味着在二次分离矩阵之外与 LFS 刮离层磁性断开的区域,密度要低得多。此外,我们还观察到,当主分离矩阵和次级分离矩阵之间的间距低于某一特定值时,在 HFS 分流器中经常出现的大密度会急剧下降。这个值对于 L 模式和 H 模式等离子体是不同的,并且与在 LFS 中平面测量到的功率衰减长度非常吻合。我们还展示了当离子梯度-B 漂移指向下方时,上单空的 HFS 刮除层密度如何小于下单空。这种差异很可能是由于在将有源 X 点从底部切换到顶部时,有源分流器中的 E×B 漂移发生了逆转。我们进一步观察到,下部分流器中的中性密度也与等离子体形状和 HFS 刮除层中的高密度区域相关。在本文分析的形状扫描过程中,HFS分流器始终保持部分分离,并在H模式下通过ELM活动调制短暂的重新附着。这项工作提供了新颖的实验数据,可用于进一步提高建模能力和对高形状等离子体中刮离层物理学的理解。
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引用次数: 0
On electromagnetic turbulence and transport in STEP 关于 STEP 中的电磁湍流和传输
IF 2.2 2区 物理与天体物理 Q2 PHYSICS, FLUIDS & PLASMAS Pub Date : 2024-03-28 DOI: 10.1088/1361-6587/ad366f
M Giacomin, D Kennedy, F J Casson, Ajay C J, D Dickinson, B S Patel, C M Roach
In this work, we present first-of-their-kind nonlinear local gyrokinetic (GK) simulations of electromagnetic turbulence at mid-radius in the burning plasma phase of the conceptual high-β, reactor-scale, tight-aspect-ratio tokamak Spherical Tokamak for Energy Production (STEP). A prior linear analysis in Kennedy et al (2023 Nucl. Fusion63 126061) reveals the presence of unstable hybrid kinetic ballooning modes (KBMs), where inclusion of the compressional magnetic field fluctuation, δB, is crucial, and subdominant microtearing modes (MTMs) are found at binormal scales approaching the ion-Larmor radius. Local nonlinear GK simulations on the selected surface in the central core region suggest that hybrid KBMs can drive large turbulent transport, and that there is negligible turbulent transport from subdominant MTMs when hybrid KBMs are artificially suppressed (through the omission of δB). Nonlinear simulations that include perpendicular equilibrium flow shear can saturate at lower fluxes that are more consistent with the available sources in STEP. This analysis suggests that hybrid KBMs could play an important role in setting the turbulent transport in STEP, and possible mechanisms to mitigate turbulent transport are discussed. Increasing the safety factor or the pressure gradient strongly reduces turbulent transport from hybrid KBMs in the cases considered here. Challenges of simulating electromagnetic turbulence in this high-β regime are highlighted. In particular the observation of radially extended turbulent structures in the absence of equilibrium flow shear motivates future advanced global GK simulations that include δB.
在这项工作中,我们首次对概念性高β、反应堆规模、紧纵横比托卡马克球形能源生产托卡马克(STEP)燃烧等离子体阶段中半径处的电磁湍流进行了非线性局部陀螺动能(GK)模拟。肯尼迪等人(2023 Nucl. Fusion63 126061)的先期线性分析揭示了不稳定混合动能气球模式(KBMs)的存在,其中包含压缩磁场波动δB∥至关重要,并且在接近离子-拉莫尔半径的双法尺度上发现了次主导微撕裂模式(MTMs)。在中央核心区域所选表面上进行的局部非线性 GK 模拟表明,混合 KBM 可以驱动大量的湍流输运,而当混合 KBM 被人为抑制时(通过省略 δB∥),亚主导 MTM 的湍流输运可以忽略不计。包含垂直平衡流切变的非线性模拟可以在较低的通量下达到饱和,这与 STEP 中的可用源更为一致。该分析表明,混合 KBM 在 STEP 中的湍流输运设置中可能发挥重要作用,并讨论了减轻湍流输运的可能机制。在本文所考虑的情况下,提高安全系数或压力梯度可极大地减少混合 KBM 的湍流传输。在这种高β机制下模拟电磁湍流所面临的挑战得到了强调。特别是在没有平衡流动剪切力的情况下观察到径向扩展的湍流结构,激励了未来包括 δB∥ 的先进全球 GK 模拟。
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引用次数: 0
Decoupled magnetic control of spherical tokamak divertors via vacuum harmonic constraints 通过真空谐波约束实现球形托卡马克转发器的解耦磁控制
IF 2.2 2区 物理与天体物理 Q2 PHYSICS, FLUIDS & PLASMAS Pub Date : 2024-03-19 DOI: 10.1088/1361-6587/ad319d
O P Bardsley, J L Baker, C Vincent
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 (4) 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.
功率耗尽是球形托卡马克反应堆面临的一个关键挑战,因此设计、优化和控制先进的岔流器配置至关重要。如果能独立改变堆芯和岔流器区域的极性磁场,就能大大简化这些任务。我们提出了一种新方法,利用真空球谐波(SH)约束,将堆芯等离子体平衡与岔流器几何优化和控制解耦。这种方法的优点是避免了对 Grad-Shafranov 方程的迭代求解,使用方便、快速、可靠。通过将大量的 MAST-U 平衡重建与使用 SH 的近似值进行比较,我们发现少量(∼4)的谐波就足以密切再现等离子体的边界形状。我们的实验表明,为使谐波不受影响而设计的极性场变化确实对核心等离子体的形状没有影响。如果再加上分流器的几何约束,这种方法就为创建先进的磁配置提供了强大的工具,而且在解决线圈位置优化问题时,它的简便性提高了速度和稳健性。我们讨论了实时反馈控制、前馈方案设计和线圈组优化对未来反应堆的明显好处。
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引用次数: 0
Multi-machine benchmark of the self-consistent 1D scrape-off layer model DIV1D from stagnation point to target with SOLPS-ITER 利用 SOLPS-ITER 对从停滞点到目标的自洽一维刮削层模型 DIV1D 进行多机基准测试
IF 2.2 2区 物理与天体物理 Q2 PHYSICS, FLUIDS & PLASMAS Pub Date : 2024-03-15 DOI: 10.1088/1361-6587/ad2e37
G L Derks, E Westerhof, M van Berkel, J H Jenneskens, J T W Koenders, S Mijin, D Moulton, H Reimerdes, H Wu
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.
本文扩展了基于物理的一维动态刮除层(SOL)等离子体模型 DIV1D,以包括核心 SOL 和可能的第二个目标。该扩展模型在一维映射 SOLPS-ITER 模拟中进行了基准测试,以找到 DIV1D 的输入设置,使其能够描述从上游到目标的 SOL 等离子体--在场景和设备的基础上对其进行校准。基准测试表明,DIV1D 和一维绘制的 SOLPS-ITER 曲线在热通量、电子温度和电子密度方面的定量匹配度大约在 50%以内:(1)托卡马克配置变量(TCV)的气体脉冲扫描;(2)升级版兆安培球形托卡马克的单次 SOLPS-ITER 模拟;以及(3)加兴托卡马克轴对称分流器实验(AUG)的升级版轴对称分流器实验(AUG)的加热功率和气体脉冲同步扫描。校准后,DIV1D 自洽地描述了在 TCV 密度扫描中 SOL 解决方案对核心通量和外部中性气体密度的依赖关系,而在 AUG 的 DIV1D 中则使用不同的 SOL 宽度来匹配功率和密度的同步变化。通过使用有效通量扩展因子考虑跨场传输,并允许中性气体在 SOL 和相邻畴之间交换,DIV1D 能够在方案和设备基础上进行校准。
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引用次数: 0
Spin-polarized 3He shock waves from a solid-gas composite target at high laser intensities 高激光强度下来自固体-气体复合靶的自旋偏振 3He 冲击波
IF 2.2 2区 物理与天体物理 Q2 PHYSICS, FLUIDS & PLASMAS Pub Date : 2024-03-14 DOI: 10.1088/1361-6587/ad30c0
L Reichwein, X F Shen, M Büscher, A Pukhov
We investigate collisionless shock acceleration of spin-polarized 3He for laser pulses with normalized vector potentials in the range a0=100200. 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.
我们研究了归一化矢量势在 a0=100-200 范围内的激光脉冲对自旋极化 3He 的无碰撞冲击加速。二维粒子池内模拟中使用的装置包括放置在主氦气靶前的固体碳箔。碳箔被激光脉冲加热,屏蔽了氦的高振荡场。反过来,具有更均匀场的冲击波被诱发,从而产生高度极化的离子束。我们观察到,在模拟中加入辐射反应会导致更高的离子束电荷量,而不会对极化程度产生重大影响。
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Plasma Physics and Controlled Fusion
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