钨中氘热脱附特性的定量研究

Quantitative study on thermal desorption of deuterium in tungsten

摘要:

金属钨(W)是未来聚变堆反应环境中面向等离子体的主要候选材料之一,开展W中氢同位素输运和滞留行为的定量研究,对评估钨的服役性能及聚变堆燃料的物料平衡至关重要。本工作采用热脱附谱方法定量研究了多晶W经能量为100 eV/D、注量为3.8×10²⁴ D/m²的D⁺辐照作用后,在不同升温速率下氘的热脱附特性。研究发现,氘的热脱附量在不同升温速率下均为10²² D₂/m²量级，随着升温速率的增大,氘的热脱附峰峰位向高温方向移动。多晶W中氘的热脱附行为符合一级反应特征,钨中空位是氘在钨中的主要俘获态,D原子的热脱附能为1.04 eV。

Abstract:

Tungsten (W) is one of the primary plasma-facing materials candidate for fusion reactor in the future. It is very significant to carry out a quantitative study on the movement and retention behavior of hydrogen isotopes in W, since it can be used to evaluate the service performance of tungsten and the material balance of fusion reactor fuel. In this work, polycrystalline W was irradiated with 100 eV D⁺ ions to the fluence of 3.8 × 10²⁴ D/m². And the subsequent thermal desorption characteristics of polycrystalline W at different heating rates were investigated by thermal desorption spectroscopy. The tota amount of deuterium desorption is about 10²² D₂/m² orders of magnitude. In particular, the thermal desorption peaks can shift to higher temperature side as the increase of heating rate. The thermal desorption behavior of deuterium in polycrystalline W is in accord with the first order reaction. The vacancies formation is the main trapping state of deuterium, and the thermal desorption energy of D atom is 1.04 eV.