老化钯的吸氚速率

摘要

The pressure of tritium gas as a function of time during it was being absorbed either by 5. 9-year-aged palladium powder with helium-to-palladium atomic ratio 0. 199 or by fresh palladium powder was experimentally measured for initial pressure 350 kPa tritium gas. Mechanism of palladium tritium-absorption and aging effects on palladium tritium absorption rate were analysed. The results indicate that the tritium absorption pressure of fresh palladium decreases rapidly in 5 s and the tritium absorption pressure of 5. 9-year-aged Pd of which the atomic ratio to He is 0. 199 decreases slowly. The atomic ratio of tritium and palladium of fresh palladium reaches to 0. 3 in 5 s, and the atomic ratio of tritium and palladium of aged palladium is just 0. 07. The tritium absorption rate of fresh palladium maxes out to 0. 11/s in 2 s, and falls down rapidly to 0. 02/s in 6 s. The tritium absorption rate of aged palladium reaches to maximum value at 0. 02/s in 1 s, and then falls down slowly. The tritium absorption rate of fresh palladium maxes out at α + β-phase, and the tritium absorption rate of aged palladium at α-phase. The 3 He that emerges from the decay of tritium blocks the diffusion of tritium and influences the tritium absorption rate.%研究了老化5.9a、N0(He)/N0 (Pd) =0.199的老化钯和新鲜钯粉在350 kPa条件下吸氚压力随时间的变化规律,分析了钯吸氚反应机制以及老化对钯吸氚速率的影响因素.结果表明:新鲜钯吸氚压力在5s内迅速降低,老化钯吸氚压力降低缓慢；新鲜钯在5s内吸氚量达到N(T)/N(Pd) =0.3,而老化钯N(T)/N(Pd)=0.07;新鲜钯吸氚速率在2s内达到最大值0.11/s,6s时吸氚速率迅速下降至0.02/s;老化钯吸氚速率在1s内达到最大值0.02/s,之后吸氚速率缓慢下降；新鲜钯的最大吸氚速率在α+β相区,而老化钯的最大吸氚速率左移至α相区.钯在贮氚老化时氚衰变产生的3 He阻碍氚在钯内部的扩散,影响钯的吸氚速率.