STATIC PROPERTIES OF ONE HE-3 IMPURITY IN SUPERFLUID HE-4

We have studied the problem of one He-3 impurity in bulk He-4 using th e diffusion Monte Carlo (DMC) method. In order to obtain sensitive res ults, the reweigthing configurations technique, applicable in variatio nal calculations, has been extended to the DMC approach. Results for t he chemical potential and the radial distribution functions are then p resented. The Hellman-Feynman theorem has been used to obtain exactly (apart from statistical errors) the kinetic energy of the impurity (T- 3) Our results for T-3 are appreciably larger than recent experimental neutron scattering determinations.