Experimental and theoretical study of the radial density distributions of large3Hedroplets

The integral cross sections of large ${}^3\mathrm{He}$ droplets and the number of atoms in the corresponding droplets $(\overline{N}=2\mathrm{}\times {10}^3–2\times {10}^4\mathrm{atoms})$ have been measured in molecular-beam scattering experiments. The experimental results are in very good agreement with integral cross sections calculated from the radial density distributions predicted from density-functional theory calculations. The experimentally confirmed theoretical 10–90% surface thicknesses vary between 8.0 Å $\left(\overline{N}{=10\mathrm{}}^3\right)$ and 7.6 Å $(\overline{N}=4\mathrm{}\times {10}^4)$ and are about 30% larger than calculated for ${}^4\mathrm{He}$ droplets of similar sizes.