Realization of the triple points of hydrogen by an open cell method using a GM closed-cycle refrigerator

摘要

The triple point of equilibrium hydrogen is realized by an open cell method using a GM closed cycle helium refrigerator. It is confirmed that there are some correlations between the triple point temperature of hydrogen and a catalyst used for the ortho-para equilibration, i.e. in the case of 0.1 mmol hydrogen with a small amount of catalyst of 0.2 g of ferric hydroxide, the triple point temperature is about 0.2 mK higher than those of the samples covered with catalysts.