報(bào)告時(shí)間：2026年3月30日（星期一）10:00

報(bào)告地點(diǎn)：材料樓601室

報(bào) 告 人：高亮 博士

工作單位：德國(guó)亥姆霍茲國(guó)家研究中心聯(lián)合會(huì)于利希研究中心等離子體物理所

舉辦單位：材料科學(xué)與工程學(xué)院

報(bào)告簡(jiǎn)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)

報(bào)告人簡(jiǎn)介：

高亮，男，博士。自2010年在中科院等離子體物理研究所讀博，2011年獲得‘中科院-馬普學(xué)會(huì)博士生聯(lián)合培養(yǎng)計(jì)劃’獎(jiǎng)學(xué)金資助前往德國(guó)馬普學(xué)會(huì)等離子體物理研究所深造，師從Christian Linsmeier教授并在Wolfgang Jacob資深研究員領(lǐng)導(dǎo)的研究小組繼續(xù)從事聚變等離子體與材料表面相互作用PSI (Plasma-Surface Interaction)方向的實(shí)驗(yàn)研究。研究課題主要集中于聚變鎢面向等離子體材料與氫同位素及氦等離子體相互作用，涉及氫、氘、氦等離子體輻照損傷及缺陷演化，以及這些元素在鎢材料中的滯留、擴(kuò)散及滲透行為研究。2015年博士畢業(yè)后繼續(xù)在馬普等離子體所從事博士后研究工作并于2017年獲得歐洲聚變委員會(huì)（Eurofusion）青年研究員項(xiàng)目資助獨(dú)立承擔(dān)“聚變等離子體雜質(zhì)對(duì)氫同位素滯留、擴(kuò)散及滲透行為影響”。該項(xiàng)目每年在全歐盟范圍內(nèi)僅遴選5-10名新晉畢業(yè)博士進(jìn)行為期兩年約15-20萬(wàn)歐元的資助。2018年底項(xiàng)目結(jié)題后繼續(xù)在IPP Garching從事博士后研究工作兩年。2020年起至今就職于德國(guó)亥姆霍茲國(guó)家研究中心聯(lián)合會(huì)于利希研究中心等離子體物理所，從事氫同位素及氦等輕質(zhì)元素在核聚變材料內(nèi)的行為研究，負(fù)責(zé)TDS實(shí)驗(yàn)室日常運(yùn)作。至今已在德國(guó)從事高水平科學(xué)研究15年，其間指導(dǎo)博士研究生5名、碩士研究生8名。發(fā)表學(xué)術(shù)論文、專(zhuān)著40余篇，被引用900余次。其中以第一作者和通訊作者在國(guó)際核心期刊發(fā)表論文20篇，包括在A(yíng)cta Materialia, Nuclear Fusion 等相關(guān)領(lǐng)域頂級(jí)期刊。多次參與聚變材料領(lǐng)域的重要國(guó)際會(huì)議進(jìn)行學(xué)術(shù)交流，受邀在國(guó)際原子能機(jī)構(gòu)IAEA Technical meeting on defect stabilization and hydrogen supersaturation (Aix en Provence, April, 2022)，面向等離子體材料與部件國(guó)際會(huì)議（International Conference on Plasma-Facing Materials and Components for Fusion Applications）, 聚變等離子體與表面相互作用（International Conference on Plasma-Surface Interactions in Controlled Fusion）等本領(lǐng)域重要國(guó)際會(huì)議做大會(huì)邀請(qǐng)報(bào)告，并以科研項(xiàng)目合作及講座形式與國(guó)內(nèi)多家科研院所一直保持緊密合作關(guān)系。