Thermal conductivity of solid deuterium by the 3ω method

Abstract

The thermal conductivity of solid D2 is measured by the 3ω method, in which a wire embedded in the medium serves as both a heater and a temperature sensor. Conductivity values are obtained by fitting experimental data with a two-dimensional model that calculates heat flow in both the axial and radial directions as a function of frequency. The model provides the thermal conductivity of D2 from the measurement of the 3ω voltage and published values of specific heat and density of D2 and of the sensor wire, and thermal conductivity values for the sensor wire. Data for D2 gas and liquid are obtained for comparison to solid D2. Conductivity values obtained for solid D2 range from 0.35 ± 0.01 W/(m K) at 18.6 K to 0.75 ± 0.02 W/(m K) at 13.4 K and are the same for normal and ortho D2. These values are acquired at lower temperatures than the 3ω method has previously been used for.

Multifunctional Skin‐Like Electronics for Quantitative, Clinical Monitoring of Cutaneous Wound Healing

“…The amplitude of temperature oscillations at the fractal sensor (Figure e) decreases sharply from the EES and its point of skin contact, and later converges in the dermis layer. The characteristic distribution of these curves follows expected patterns as reported earlier . For frequencies used in our clinical studies (i.e., V 3ωL = 1 Hz and V 3ωH = 3 Hz), the measured thermal conductivity is influenced by properties of both the epidermis and dermis.…”