高密度氦相变的分子动力学研究

Molecular dynamics study on the phase transition of high density helium

采用分子动力学方法结合对关联函数分析计算了0—1000 K范围内氦的固—液相变曲线,与实验数据的对比显示,在0—500 K之间与实验数据符合很好,500 K以上还没有相应的实验数据.另外,计算了钛金属中不同尺寸氦泡的压强,并与高密度氦的固—液相变曲线进行了对比.结果显示,在低温条件下,随着温度的降低,钛晶体中可能会出现固态氦泡;在300 K以上不会存在固态氦泡.

The melting curve of helium has been calculated over the temperature range of 0--1000 K using molecular dynamics method. Comparisons of the calculated melting curve and the experimental data show that the consistence between the melting curve and the experimental data may reach 500 K. When the temperature is above 600 K, no reliable experimental data have been found for comparison. In addition, the pressures inside the helium bubbles of various sizes existing in metal titanium are calculated and have a comparison with the melting curve. Results show that, at low temperatures, the helium bubbles may be in solid state as the temperature decreases. When the temperature is above 300 K, no solidhelium bubble may exist.