  The determination of smuon and neutralino masses in smuon pair production is
an important part of the program of spectroscopic studies of Supersymmetry at a
high energy linear collider. In this note we report the first results of a
study of e+e- -> ~mu_R+ ~mu_R- in a high-mass, cosmology-motivated
Supersymmetric scenario at 3 TeV at CLIC. This process is a good example to
study requirements on the beam energy spectrum and polarisation and the track
momentum resolution in a simple final state. We discuss the expected accuracy
on the mass measurements as a function of the momentum resolution, luminosity
spectrum, beam polarisation and time stamping capability. Results obtained at
generator level are validated by comparison to full simulation and
reconstruction. Preliminary requirements for the detector performances and beam
polarisation are presented.
