Abstract
Gravitational wave (GW) has been predicted by Einstein's theory of general relativity, however, GW has never been detected directly. The Large-scale Cryogenic Gravitational wave Telescope (LCGT) is a future project planned by Japan to detect GW utilizing interferometry. In the LCGT, the mirrors will be cooled to suppress thermal noise. Heat links made of pure metal wires with high thermal conductivity will be utilized to maintain the mirrors at low temperature. In order to design the heat links, RRRs, thermal conductivity, mechanical Q-factors and Young's moduli of pure aluminum (Al) and copper (Cu) wires with various diameters were measured at low temperature. Based on these measurements, we have designed a heat link that has sufficiently large thermal conductance with small vibration noise.
