Equation of state for interacting neutron fluid at high temperatures

The equation of state of a system of interacting neutrons is calculated using the classical hypernetted chain approximation in the density and temperature ranges ${10}^{11}$-3 × ${10}^{14}$ g/${\mathrm{cm}}^3$ and 6 × ${10}^{10}$ - ${10}^{12}$ ${}_{}{}^{\mathrm{°}}{}_{}{}^{}\mathrm{K}$ respectively. The resulting equation of state is found to deviate from the ideal-gas law. The importance of this deviation for supernova hydrodynamics is pointed out.