세미나

Most sub-Kelvin refrigerators have been developed to meet the rigorous demands of scientific inquiry. These advanced cooling devices include sorption-based evaporation cooler, Helium3-Helium4 dilution refrigerators, and adiabatic demagnetization refrigerators (ADRs), each of which utilizes fundamental principles such as evaporation cooling, phase separation, and the magnetocaloric effect. Recently, however, sub-Kelvin cooling has gained significant attention beyond the realm of pure scientific research, driven by the needs of quantum sensing, communication, and computing technologies. These quantum information technologies require engineering advancements to involve less costly and more reliable cryogenic refrigeration systems. Cryogenics originates from the Greek word CRYO, which means – cold, and the word GEN, which means generate in English. Nowadays, cryogenics includes all phenomena occurring below approximately -150 °C or 120 K, much lower temperature than what we can experience on earth. There is evident reason for treating cryogenics as a special field even though it is different from other fields just in terms of temperature. The physical properties of materials at very low temperature differ so dramatically from those usually encountered that people cannot just deduce the peculiar characteristics of cryogenics from their general intuition. Cryogenic engineering is a technology that treats unusual phenomena at low temperature, covering not only physics but also chemistry, biology, mechanics, etc. This talk will introduce several interesting applications of cryogenic engineering that are categorized as superconducting technology, gas separation & liquefaction, and energy applications. They are sometimes invisibly incorporated already in our modern society and advanced science and energy systems.