The Effects of Liquid Cryogen on the Thermal/Electrical Characteristics of a GdBCO Coil in a Mixed Cryogen Cooling System

The electrical and thermal properties of a mixed cryogen-cooled 2G HTS coil with respect to liquid cryogen amount were examined to investigate the influence of the solid/liquid ratio on the thermal/electrical stabilities of the GdBCO coil. Thermal contact between the GdBCO coil and solid nitrogen was considerably improved as the amount of liquid neon (LNe) increased. Minimum quench energy values of the GdBCO coil were saturated as the amount of liquid neon increased, which suggested that the excessive LNe was not effective for enhancing the thermal stability of the GdBCO coil. The temperature traces of the GdBCO coil during the quench/recovery tests confirmed that the thermal stability of the coil was enhanced with the aid of the LNe.