Division of accelerators, cryogenics and magnetism

To develop basic technologies for the maritime transport of hydrogen energy, a liquid hydrogen experiment facility (LHEF) with system enabling observation under horizontal vibration has been designed and constructed. The LHEF consists of a liquid hydrogen (LH₂) optical cryostat, a gas-handling system, vacuum pumps, and apparatus for generating horizontal vibrations. The results of performance tests show that the heat leak in the LH₂ space is sufficiently small. Using the LHEF under horizontal vibration, the damped oscillation of the LH₂ surface is successfully observed and analyzed on the basis of a simple model in comparison with other cryogens, e.g., liquid nitrogen, liquid helium, and superfluid helium. In addition, characteristics of magnesium diboride (MgB₂) sensor for detecting level of LH₂ are studied by means of the LHEF.

Minoru TAKEDA

Graduate School of Maritime Sciences, Kobe University, JAPAN