Deuterium recombination coefficients on pure tungsten have been experimentally studied. Tungsten samples were continuously exposed to deuterium RF plasma and, simultaneously, deuterium surface densities and bulk concentrations were observed by using a nuclear reaction analysis. From consideration of deuterium particle balance between surface and bulk, the recombination coefficient on the plasma-exposed surface, k_u = 4.5 × 10~(-25) exp(-0.78 eV/kT) m~4 s~(-1), was obtained at temperature range of 426-654 K. A potential energy diagram for hydrogen (deuterium) near tungsten surface was proposed based on the results. The diagram indicates that tungsten hardly absorbs hydrogen molecules and hydrogen atoms once entering into tungsten are not easily desorbed due to a high potential barrier between surface and vacuum.
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机译:已经通过实验研究了纯钨上的氘复合系数。钨样品连续暴露于氘RF等离子体中,同时,通过使用核反应分析观察到氘的表面密度和体积浓度。考虑到氘在表面和体积之间的平衡,等离子体暴露表面的复合系数k_u = 4.5×10〜(-25)exp(-0.78 eV / kT)m〜4 s〜(-1)为在426-654 K的温度范围内获得。基于该结果,提出了钨表面附近氢(氘)的势能图。该图表明,钨几乎不吸收氢分子,并且一旦进入钨,由于表面和真空之间的高势垒,氢原子就不容易被解吸。
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