报告时间：2026年3月30日（星期一）10:00
报告地点：材料楼601室
报 告 人：高亮 博士
工作单位：德国亥姆霍兹国家研究中心联合会于利希研究中心等离子体物理所
举办单位：材料科学与工程学院
报告简介：
Hydrogen isotopes (HI) retention in tungsten (W) plasma-facing material (PFM) is dominated by trapping at irradiation-induced defects. To create irradiation defects (i.e., stable Frenkel pairs) in W, a minimum energy transfer of ~40 eV from the incident particle to the lattice atom is required; equivalent to incident ion energies of ~1840 eV for hydrogen (H), ~920 eV for deuterium (D) or ~600eV for tritium (T) [1, 2]. However, this conventional displacement damage threshold is challenged by the observation of HI-supersaturated surface layers (SSL) in low-energy HI (415/215 eV for H/D) plasma-exposed W [3-5]. So far the underlying mechanisms of such lattice damage at <10 eV energy transfer and the resulting SSL formation are still missing. Herein we first revisit the fundamental displacement process taking into account the free surface acting as defect sinks nearby the collision sites in W upon low-energy HI plasma exposure. The corresponding threshold energy transfer to produce lattice defects in W is demonstrated to be only 5±1 eV at 300 K, being significantly lower than the theoretical formation energy of SIA in W matrix (9.6 eV [2]). A novel physical model based on the lattice cohesion weakening induced by interstitial HI is accordingly presented. Next, the focus will be set on another damage mechanism of H-induced intra-granular cracking [6, 7]. A series of dedicatedly designed experiments will be presented toward a physical understanding of such H-induced cracking of W grains under plasma exposure.
The concerted defect production in W lattice due to the co-existence of interstitial H and nearby defect sinks under HI plasma exposure applies also to future fusion devices: under high-energy neutron irradiation, interstitial H/He atoms via diffusion or transmutation-induced gas production will present in PFM lattice presenting nearby defect sinks (cracks, interfaces, grain- and phase-boundaries, etc.). The resulting saturation level of fuel retention shall be significantly enhanced, and therefore, should be monitored and avoided as much as possible.
[1] F. Maury et al., Radiation Effects 38, 53-65 (1978).
[2] K. Nordlund et al., J Nucl Mater 512 450-479 (2018).
[3] L. Gao et al., Nucl. Fusion 57 016026 (2017).
[4] L. Gao et al., Acta Mater. 201 55 (2020).
[5] L. Gao et al., Acta Mater. 256 119137 (2023)
[6] L. Gao et al., Nucl. Fusion 59 056023 (2019)
[7] A. Manhard, L. Gao. Nucl. Mater. Energy 17, 248 (2018)
报告人简介：
高亮，男，博士。自2010年在中科院等离子体物理研究所读博，2011年获得‘中科院-马普学会博士生联合培养计划’奖学金资助前往德国马普学会等离子体物理研究所深造，师从Christian Linsmeier教授并在Wolfgang Jacob资深研究员领导的研究小组继续从事聚变等离子体与材料表面相互作用PSI (Plasma-Surface Interaction)方向的实验研究。研究课题主要集中于聚变钨面向等离子体材料与氢同位素及氦等离子体相互作用，涉及氢、氘、氦等离子体辐照损伤及缺陷演化，以及这些元素在钨材料中的滞留、扩散及渗透行为研究。2015年博士毕业后继续在马普等离子体所从事博士后研究工作并于2017年获得欧洲聚变委员会（Eurofusion）青年研究员项目资助独立承担“聚变等离子体杂质对氢同位素滞留、扩散及渗透行为影响”。该项目每年在全欧盟范围内仅遴选5-10名新晋毕业博士进行为期两年约15-20万欧元的资助。2018年底项目结题后继续在IPP Garching从事博士后研究工作两年。2020年起至今就职于德国亥姆霍兹国家研究中心联合会于利希研究中心等离子体物理所，从事氢同位素及氦等轻质元素在核聚变材料内的行为研究，负责TDS实验室日常运作。至今已在德国从事高水平科学研究15年，其间指导博士研究生5名、硕士研究生8名。发表学术论文、专著40余篇，被引用900余次。其中以第一作者和通讯作者在国际核心期刊发表论文20篇，包括在Acta Materialia, Nuclear Fusion 等相关领域顶级期刊。多次参与聚变材料领域的重要国际会议进行学术交流，受邀在国际原子能机构IAEA Technical meeting on defect stabilization and hydrogen supersaturation (Aix en Provence, April, 2022)，面向等离子体材料与部件国际会议（International Conference on Plasma-Facing Materials and Components for Fusion Applications）, 聚变等离子体与表面相互作用（International Conference on Plasma-Surface Interactions in Controlled Fusion）等本领域重要国际会议做大会邀请报告，并以科研项目合作及讲座形式与国内多家科研院所一直保持紧密合作关系。
