克雷西 发自 凹非寺 量子位 | 公众号 QbitAI 中国"人造太阳"，又有新突破！ 华中科技大学朱平教授和中科院合肥研究院严宁副教授共同领导的托卡马克实验装置研究，登上了Science子刊。 这项研究验证了了边界等离子体与壁相互作用自组织（PWSO）理论模型，从实验上确认了托卡马克运行中长期存在的密度极限背后机理。 该发现证实了托卡马克中 密度自由区 （density-free regime）的存在，成功 突破密度极限 ，为聚变点火提供了新的路径。 密度极限，聚变效率的天堑 在"人造太阳"，即磁约束核聚变的研究过程中，科学家们始终面临着一个核心物理难题——如何在维持等离子体宏观稳定的前提下，大幅提升 其粒子密度。 这是因为根据衡量核聚变能否发生点火及实现能量净增益的"劳森判据"（Lawson Criterion）， 聚变反应的发生条件取决于等离子体密度、 温度以及能量约束时间的乘积 。 这是由核聚变反应最基础的二体碰撞物理机制决定的。由于聚变反应发生的前提是两个原子核在极高速度下发生"迎头相撞"并克服库仑斥力， 其反应发生的概率本质上取决于单位体积内参与碰撞的粒子数的乘积。 这意味着， 聚变输出功率密度与 ...

Core Insights - The International Atomic Energy Agency (IAEA) has released the "Fusion Energy Outlook 2025," indicating that global fusion energy exploration has entered a decisive new phase in 2023 [1] - Significant milestones have been achieved in fusion energy, particularly by the United States and China, with the U.S. National Ignition Facility (NIF) claiming a Q value greater than 4 and China's BEST project entering the assembly phase [1][2] - The report highlights a growing competition between the U.S. and China in the fusion energy sector, with increasing investments and advancements in technology [12][21] Investment and Funding - Global funding for fusion enterprises has surpassed the total amount raised in the previous year, reaching a historical high by September 2023 [13] - China's cumulative funding in fusion energy, approximately $5 billion, is still less than the U.S.'s $7.5 billion, but since 2023, China's annual funding has exceeded that of the U.S. [14] - The U.S. report indicates that China has mobilized up to $13 billion for fusion infrastructure since 2023, significantly outpacing U.S. investments [17] Technological Advancements - Fusion performance has improved tenfold over the past decade, with projections indicating that the 2030s will be a critical decade for fusion power generation [3][6] - The Lawson criteria, which determines the energy gain of fusion systems, shows that the three-product (temperature, fuel density, and confinement time) is improving at a rate of one order of magnitude every ten years [4][5] Global Competition - The U.S. and China are positioned as the primary competitors in the commercial fusion energy race, with both countries' projects nearing operational status [12][21] - The report notes that 27% of the papers submitted to the IAEA Fusion Energy Conference in 2025 are from China, surpassing the combined contributions from the U.S. and Japan [21] Supply Chain Concerns - The U.S. faces significant challenges regarding supply chain security in the fusion sector, particularly in critical minerals and components where China holds a dominant position [23][26] - Key materials such as tungsten and lithium-6 are primarily produced by China and Russia, raising concerns for U.S. energy independence [26][27] Strategic Recommendations - The U.S. report emphasizes the urgency for increased government funding and subsidies to maintain competitiveness in the fusion energy sector [28]