Parameters
There are some issues to be discussed. Beam radius 3.5 cm Suspension length 40 cm Diameter of suspension fiber 1.8 mm Number of suspension fiber 4 Temperature of suspension 16 K Mechanical loss of fiber 2e-7 Mirror radius 12.5 cm Mirror thickness 15 cm Bulk absorption 20 ppm/cm Coating absorption 0.1 ppm Temperature of mirrors 20 K Mechanical loss of a mirror 1e-8 Number of coating layers (ITM) 9 Number of coating layers (ETM) 18 Mechanical loss of Silica coatings 1e-4 Mechanical loss of Tantala coatings 4e-4 Optical loss of each arm 70 ppm/roundtrip Optical loss in the SRC 2% Optical loss at the PD 10%
Material properties
Young's modulus of Sapphire 4e11 Pa Density of Sapphire 4e3 kg/m^3 Poisson ratio of Sapphire 0.29 Thermal expansion of Sapphire (20K) 5.6e-9 1/K Specific heat of Sapphire (20K) 0.69 J/K/kg Thermal conductivity of Sapphire (20K) 1.57e4 W/m/K Thermal expansion of Sapphire (300K) 5.0e-6 1/K Specific heat of Sapphire (300K) 790 J/K/kg Thermal conductivity of Sapphire (300K) 40 W/m/K Young's modulus of Silica 7.2e10 Pa Poisson ratio of Silica 0.17 Refraction index of Silica 1.45 Thermal expansion of Silica (300K) 5.1e-7 1/K Specific heat per volume of Silica (300K) 1.64e6 J/K/m^3 Thermal conductivity of Silica (300K) 1.38 W/m/K dn/dT of Silica (300K) 8e-6 1/K Young's modulus of Tantala 1.4e11 Pa Poisson ratio of Tantala 0.23 Refraction index of Tantala 2.06 Thermal expansion of Tantala (300K) 3.6e-7 1/K Specific heat per volume of Tantala (300K) 2.1e6 J/K/m^3 Thermal conductivity of Tantala (300K) 33 W/m/K dn/dT of Tantala (300K) 14e-6 1/K