磁流体动力学如何描述导电流体与磁场的耦合？
How does magnetohydrodynamics describe the coupling of conducting fluid and magnetic field?
磁流体动力学把等离子体视为连续导电流体，将纳维-斯托克斯方程与麦克斯韦方程结合：磁场随流体运动而扭曲，流体运动又受洛伦兹力反作用。它用于描述太阳风、地磁发电机等天体等离子体现象。
Magnetohydrodynamics treats plasma as a continuous conducting fluid, coupling Navier–Stokes with Maxwell's equations: the field is distorted by flow, and flow is acted on by the Lorentz force. It describes astrophysical plasmas such as the solar wind and the geomagnetic dynamo.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
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出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
Nature Physics — 天体等离子体专题
Nature Physics — astrophysical plasma feature
#磁流体动力学 #洛伦兹力 #导电流体
惯性约束聚变用激光如何实现点火？
How do lasers achieve ignition in inertial confinement fusion?
强激光从四面均匀轰击毫米级燃料靶丸，使其外层烧蚀反冲、内爆压缩到极高密度温度，惯性使燃料在飞散前完成聚变点火。美国国家点火装置在2022年首次实现能量净增益。
Intense lasers symmetrically heat a millimeter fuel pellet; ablation drives implosion to extreme density and temperature, and inertia lets fusion ignite before the fuel disperses. The US NIF achieved net energy gain in 2022.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
程守洙 江之永,《普通物理学》第七版,高等教育出版社,2016
Cheng Shouzhu and Jiang Zhiyong, General Physics, 7th ed., Higher Education Press, 2016
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787040429190（豆瓣书目条目: 普通物理学．上册）
#惯性约束聚变 #激光点火 #内爆
等离子体中的德拜屏蔽如何限制单个电荷的可见影响范围？
How does Debye shielding in plasma limit the reach of a single charge's influence?
带正电的粒子会吸引周围电子、排斥离子，形成屏蔽云，使净电场在约一个德拜长度外衰减消失，从而让等离子体在大尺度上近似保持电中性。
A positive charge attracts electrons and repels ions, forming a shielding cloud that makes the net field decay to zero beyond roughly one Debye length, keeping the plasma quasi-neutral on large scales.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
程守洙 江之永,《普通物理学》第七版,高等教育出版社,2016
Cheng Shouzhu and Jiang Zhiyong, General Physics, 7th ed., Higher Education Press, 2016
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787040429190（豆瓣书目条目: 普通物理学．上册）
#德拜屏蔽 #德拜长度 #准中性
2022年美国国家点火装置实现的聚变点火在物理上意味着什么?为什么此前难以达到?
What did the 2022 ignition achievement at the National Ignition Facility mean physically, and why had it been so hard to reach before?
2022年12月NIF向靶丸输送2.05 MJ激光能量，获得了3.15 MJ的聚变产出，首次在实验室中实现靶增益大于1（约1.5），即聚变释放的能量超过驱动内爆的激光能量。难点在于劳森判据对等离子体温度、密度和能量约束时间的乘积要求极为苛刻，而间接驱动的黑腔在X射线转换和内爆对称性环节损失了大量能量。此次成功依靠靶丸制造精度、脉冲整形和诊断技术的长期积累才跨过门槛。
In December 2022 NIF delivered 2.05 MJ of laser energy to the target and obtained 3.15 MJ of fusion output, achieving a target gain above one (about 1.5) in the laboratory for the first time — fusion energy released exceeding the laser energy driving the implosion. The difficulty lies in the Lawson criterion's extremely demanding product of plasma temperature, density, and confinement time, while the indirect-drive hohlraum loses substantial energy in X-ray conversion and implosion symmetry. Crossing the threshold required long-term advances in capsule fabrication, pulse shaping, and diagnostics.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-10-04
来源 · Source
H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022): Lawson criterion for ignition exceeded
H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022): Lawson criterion for ignition exceeded
独立核验依据 · Independent verification: 核验依据 1 DOI 10.1109/icops45751.2022.9813006
#核聚变能 #劳森判据
托卡马克放电越过一定加热功率后会突然进入H模,这种约束改善的物理根源是什么?
What is the physical origin of the abrupt confinement improvement when a tokamak discharge crosses into the H-mode past a threshold heating power?
根源是边界自发形成输运垒。功率越过阈值后,径向电场梯度驱动的E×B剪切流把边界湍流涡旋撕裂,湍流输运骤降,压强剖面在边缘出现陡峭台基,芯部密度与温度随之抬升,能量约束时间约翻倍。但台基积聚的压强会周期性地以磁流体不稳定性形式突然释放,即ELM,其脉冲热负荷冲击偏滤器,故ITER配备了专门的缓解系统。
The origin is a spontaneously formed transport barrier at the edge. Past the power threshold, sheared flow driven by the radial electric field gradient tears edge turbulent eddies apart, transport falls sharply, a steep pressure pedestal appears at the boundary, lifting core density and temperature so that the energy confinement time roughly doubles. Yet the pedestal pressure unloads periodically through magnetohydrodynamic instabilities called ELMs whose pulsed heat loads strike the divertor, which is why ITER carries dedicated mitigation systems.
难度 专业 · 适合 小学高段(9-12)
CC BY 4.0 · 来源待核验 · Source pending review
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出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
F. Wagner 等(ASDEX 团队),Physical Review Letters 第49卷1408页,1982年
F. Wagner et al., Physical Review Letters 49, 1408 (1982)
#磁约束 #边缘输运垒 #ELM爆发
等离子体频率决定了电磁信号的什么行为？
What behavior of electromagnetic signals is set by the plasma frequency?
当电磁波频率低于等离子体频率时会被反射，高于时才能穿透；这正是电离层反射短波无线电、使远距离短波通信成为可能的原因。
Electromagnetic waves below the plasma frequency are reflected; only above it can they pass through. This is why the ionosphere reflects shortwave radio, enabling long-distance communication.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
程守洙 江之永,《普通物理学》第七版,高等教育出版社,2016
Cheng Shouzhu and Jiang Zhiyong, General Physics, 7th ed., Higher Education Press, 2016
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787040429190（豆瓣书目条目: 普通物理学．上册）
#等离子体频率 #电离层 #电磁波
托卡马克如何约束上亿度的高温聚变等离子体？
How does a tokamak confine fusion plasma at over 100 million degrees?
托卡马克用强环向磁场把等离子体束缚在环形真空室中，避免其接触器壁；螺旋磁场同时抑制宏观不稳定性，是实现磁约束聚变的主要装置路线。
A tokamak uses strong toroidal magnetic fields to confine plasma inside a toroidal vacuum vessel, keeping it from the walls; the helical field also stabilizes instabilities, the leading magnetic-confinement approach.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
ITER 国际热核聚变实验堆组织
ITER International Organization
#托卡马克 #磁约束 #聚变
等离子体中的朗缪尔波是什么？
What are Langmuir waves in a plasma?
朗缪尔波是电子密度相对离子背景的纵向振荡，由电子静电恢复力驱动，频率约为电子等离子体频率，是实验室和空间等离子体中常见的静电波模式。
Langmuir waves are longitudinal oscillations of electron density against the ion background, driven by electrostatic restoring force at roughly the electron plasma frequency, a common electrostatic mode in lab and space plasmas.
难度 进阶 · 适合 大众
CC BY 4.0 · 来源待核验 · Source pending review
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出处备注：著录仅给书名，无版次与年份；同一书名常对应多个版次，不臆测具体版本。
《现代物理学评论》— 等离子体波动
Reviews of Modern Physics — plasma waves
#朗缪尔波 #等离子体波 #静电波
为什么等离子体被称为物质的第四态？
Why is plasma called the fourth state of matter?
当气体被加热或电离到足够程度，电子与离子分离形成带电粒子集合，其整体行为受电磁场支配，既非固液气，故称为第四态，也是宇宙中最常见的物态。
When gas is heated or ionized enough, electrons separate from ions into a collection of charged particles whose behavior is governed by electromagnetic fields — neither solid, liquid, nor gas, so it is the fourth state and the most common in the universe.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
程守洙 江之永,《普通物理学》第七版,高等教育出版社,2016
Cheng Shouzhu and Jiang Zhiyong, General Physics, 7th ed., Higher Education Press, 2016
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787040429190（豆瓣书目条目: 普通物理学．上册）
#等离子体 #电离 #物态
太阳风对地球有什么影响？
What effect does the solar wind have on Earth?
太阳风是太阳持续抛出的高速带电粒子流，与地球磁场相互作用形成磁层。剧烈时扰动磁层引发地磁暴和极光，也可能干扰卫星与电网。
The solar wind is a continuous stream of charged particles from the Sun; interacting with Earth's magnetic field it forms the magnetosphere. Strong events trigger geomagnetic storms and auroras and can disturb satellites and power grids.
难度 进阶 · 适合 大众
CC BY 4.0 · 来源待核验 · Source pending review
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出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
中国科学院国家空间科学中心
National Space Science Center, CAS
#太阳风 #磁层 #地磁暴
托卡马克为什么需要环向磁场和极向磁场共同作用来约束等离子体?
Why must a tokamak combine toroidal and poloidal magnetic fields to confine its plasma?
单纯环向磁场存在固有缺陷:由于环向场内侧强外侧弱,带电粒子在绕环向力线回旋的同时会发生垂直漂移,离子和电子分别向上、向下分离,造成电荷积累并破坏约束。托卡马克用中心感应电流产生极向磁场,两个场的磁力线叠加成螺旋线,粒子沿螺旋磁力线运动时漂移方向来回翻转,平均后相互抵消,等离子体得以稳定约束在环形真空室内。这一原理由苏联科学家于20世纪50年代提出并沿用至今。
A purely toroidal field is intrinsically flawed: because the field is stronger on the inner side of the ring than the outer, particles gyrating around toroidal field lines drift vertically, ions and electrons separating in opposite directions—an accumulating charge imbalance that destroys confinement. A tokamak adds a poloidal field driven by a centrally induced plasma current, so the combined field lines wind helically. As particles follow these helical lines their drift directions keep reversing, averaging to zero and letting the plasma stay confined inside the toroidal vacuum vessel. Soviet scientists proposed this scheme in the 1950s and it remains the leading magnetic-confinement concept today.
难度 进阶 · 适合 大众
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：作者 / 书名 / 版次 / 出版社 / 年份齐备，仅缺独立比对证据；已在可信度报告单列披露，不再重复核验。
李建刚《托卡马克物理基础》讲义第2章 磁约束基本原理;Wesson, Tokamaks (4th ed.), Ch. 1: Introduction to the Tokamak, 2011
Wesson, Tokamaks (4th ed.), Ch. 1: Introduction to the Tokamak (Oxford, 2011)
#磁约束 #螺旋磁力线
为什么第一代聚变堆选择氘氚反应作燃料,而不是用储量几乎无限的纯氘?
Why do first-generation fusion reactors choose the deuterium-tritium reaction as fuel instead of nearly unlimited pure deuterium?
因为DT反应所需温度最低、截面最大。它在约10~20千电子伏时反应率已接近峰值,而DD反应要高出一个数量级的温度才有可比速率,远超现有装置的约束水平。此外DT放能约八成由中子携带,便于输出产能,剩余的α粒子留在磁笼内自持加热等离子体,正是点火判据的核心。代价是氚稀缺,须用锂包层就地增殖。
Because the D-T reaction has the largest cross section at the lowest achievable temperature. Its reaction rate already approaches its peak around 10 to 20 keV, whereas the D-D branch needs temperatures roughly an order of magnitude higher for a comparable rate, beyond present confinement capability. Moreover about eighty percent of the D-T yield is carried by neutrons, convenient for power extraction, while the remaining alpha particles stay in the magnetic cage and self-heat the plasma, the heart of the ignition criterion. The price is scarce tritium, bred in situ from a lithium blanket.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-11-04
来源 · Source
J. D. Lawson,《Some Criteria for a Power Producing Thermonuclear Reactor》,Proceedings of the Physical Society. Section B 70, 6,1957 (DOI: 10.1088/0370-1301/70/1/303)
J. D. Lawson, 'Some Criteria for a Power Producing Thermonuclear Reactor', Proceedings of the Physical Society. Section B 70, 6, 1957, DOI: 10.1088/0370-1301/70/1/303
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.1088/0370-1301/70/1/303
#聚变燃料 #劳森判据 #氚增殖
国家点火装置(NIF)为何不直接照射靶丸,而是先把激光转化成X射线来驱动内爆?
Why does the National Ignition Facility convert its laser beams into X rays to drive the implosion instead of illuminating the capsule directly?
为了获得足够均匀的辐照。直接照射时光束斑不均且等离子体会使能量沉积失衡,靶丸易被压歪;把光送进圆柱形黑腔,高Z内壁反复吸收并再辐射,将192束的能量抹平为准均匀热辐射场,如烤炉般从四面八方均匀烧蚀靶丸表面。外喷物质的反冲依火箭原理向内压缩燃料,密度升逾千倍,中心热斑达点火条件,2022年12月首次实现净能量增益。
To obtain sufficiently uniform illumination. Under direct irradiation the beam spots are uneven and plasma effects unbalance the deposition, so the capsule would be squashed asymmetrically; sending the light into a cylindrical hohlraum lets the high-Z wall absorb and reradiate repeatedly, smearing the energy of the 192 beams into a quasi-uniform thermal radiation field that ablates the surface evenly from every side like an oven. The recoil of the ablating material compresses the fuel inward by rocket action, raising density over a thousandfold until the central hotspot ignites, first achieved with net energy gain in December 2022.
难度 入门 · 适合 大众
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
H. Abu-Shawareb 等(间接驱动合作组),Physical Review Letters 第132卷065102页,2024年
H. Abu-Shawareb et al., Physical Review Letters 132, 065102 (2024)
#惯性约束聚变 #间接驱动 #黑腔