The Second and Third Virial Coefficients of 3 He from 3.3 K to 13 K from Experimental Data

The second and third density virial coefficients, B and C , of helium-3 ( 3 He) are determined in the temperature range from 3.3 K to 13 K based on the analysis of experimental thermophysical data. The empirically fitted equations of B and C are obtained, which enable us to calculate the second and third acoustic virial coefficients, β a and RTγ a , of 3 He in the same temperature range. This study provides the first experiment-based values of β a and RTγ a from 3.75 K to 13 K. The obtained density and acoustic virial coefficients of 3 He are compared with previous experimental and theoretical studies.