tapes to build the superconducting magnet with an operating current of 10 A at temperatures in the range of 65 to 77 K [6]. In the superconducting magnetic energy storage (SEMS) system, the length of current lead supplying the current to the superconducting magnet was designed based on consideration of the layout of the SMES components [7]. In such superconducting magnet application systems, the current lead connecting the superconducting magnet and the power supply is very important. HTS tapes can be attractive materials for current leads because they have high current density and low thermal conductivity. Several laboratories are presently investigating the development of a current lead using HTS tapes. Research groups such as the National Institute for Fusion Science [8; 9; 10], Yonsei University [11], and Huazhong University of Science and Technology have performed research related to HTS current leads [12]. The Karlsruhe Institute of Technology has recently manufactured the HTS current leads for the current supply of the satellite tokamak JT-60 SA [13]. The aim of the development is the design and construction of a 20 kA HTS current lead using Rare-Earth Barium Copper Oxide (REBCO) material. After manufacturing of the HTS current lead, it was tested in the test facility CuLTKa. Some other researches about HTS current lead have been performed for the Italian National Institute for Nuclear Physics magnet test facility [14]. In these researches regarding the current lead using HTS materials, it is important to demonstrate the applicability of HTS current lead in the actual application scale. A research program involving the current leads for the Electromagnetic Property Measurement System (EMPS) is underway at the Korea Basic Science Institute. The objective of the project is the development of an efficient low temperature superconducting (LTS) magnet system cooled by continuous liquid helium. In addition, the LTS magnet has a wide bore as compared with the conventional device [15], therefore several samples can be installed in the magnetic space and physical and magnetic properties can be measured at the same time. The drawing of a 5 T superconducting magnet system used for property measurement applications is shown in Figure 1. As mentioned above, the system mainly consists of the superconducting magnet, current leads, and cryogenic system. The cryogenic vessel is composed of a liquid helium vessel, liquid nitrogen vessel, and a vacuum vessel. A pair of current leads is installed in the system, and both current leads are used to supply electrical current to the magnet. The 5 T superconducting magnet is installed and operated in the liquid helium vessel. The detailed specifications of the magnet are listed in Table 1. As indicated, the central magnetic field and energy of the magnet are, respectively, equal to 5.01 T and 15.2 kJ for electrical current of 45 A.  
Figure 1: Drawing of the 5 T superconducting magnet for the Electromagnetic Property Measurement System (EMPS). The vapor-cooled current lead was developed to supply current and generate an approximately magnetic field strength of 5 T in the EMPS. Design optimization was conducted to minimize helium consumption, and relevant tests were also performed. In addition, the hybrid type current lead was used because it eliminated conductive heat leakage. Figure 2 shows the detailed structure of the hybrid current lead. It is composed of (a) a metal lead made of copper or brass that conducts the current from room to an intermediate temperature, and (b) a high-temperature superconductor (HTS) lead that conducts the current at the liquid helium temperature. The metal lead is connected to the HTS lead at the joint and heat generation at the interface is affected by contact resistance [16]. As described above, two types of current lead for LTS magnet system have been proposed, in this study. The detailed design process such as material selection and size determination of vapor-cooled current lead has been investigated.