OPTICAL-CONSTANTS OF LIQUID AND SOLID METHANE

The optical constants n(r) + in(i) of liquid methane and phase I solid methane were determined over the entire spectral range by the use of various data sources published in the literature. Kramers-Kronig analy ses were performed on the absorption spectra of liquid methane at the boiling point (111 K) and the melting point (90 K) and on the absorpti on spectra of phase I solid methane at the melting point and at 30 K. Measurements of the static dielectric constant at these temperatures a nd refractive indices determined over limited spectral ranges were use d as constraints in the analyses. Applications of methane optical prop erties to studies of outer solar system bodies are described.