Helium is a typical carrier gas for GC-MS systems and is a limited and valuable material. Here, we introduce alternative gas analysis technologies that utilize hydrogen and nitrogen. When hydrogen is utilized in a GC-MS system, it is more sensitive and has better separation than nitrogen. On other hand, in the case of nitrogen, it is easier to handle as compared to hydrogen. In this paper, basics gas chromatography is explained, and the gas analysis technologies using hydrogen and nitrogen as an alternative to helium gas are described. These technologies will contribute to reducing the consumption of helium.

In order to preserve our limited resources, helium recovery systems are employed in many research facilities. In these systems, the helium gas recovered from laboratories is dried and purified and then flows into a helium liquefier. This article describes features of several types of dryers and purifiers, and introduces some examples of the recovery system.

This is a review of compact liquefaction/recondensation equipment with cryocoolers, namely, GM-coolers and pulse tube cryocoolers. The improvement of liquefaction performance is remarkable since the advent of the 4-K pulse tube cryocooler. This article describes a brief history about 4-K cryocoolers and their liquefaction performance. Additionally, commercialized helium gas liquefaction/recondensation systems with cryocoolers are introduced and those specifications are shown.

Since the degradation of a REBCO coil was reported, coil fabrication methods that can avoid delamination have been developed. Meanwhile, it is now possible to obtain various types of REBCO-coated conductors from manufacturers these days. It is unknown if there is a coil fabrication method that matches all of the REBCO-coated conductors. When a new coated conductor is to be used for coil fabrication, some preliminary tests should be carried out in advance. We propose a chisel test that reproduces delamination of the coated conductor in a REBCO coil.