  The knowledge of the spin diffusion length $\lambda_{A}$ is a prerequisite
for the estimation of the spin Hall angle. We investigate spin current
absorption of materials with small $\lambda_{A}$ using AuW stripes inserted in
lateral spin-valves. Width variations of the AuW stripe lead to drastic changes
of the spin absorption, which cannot be explained by conventional analysis. We
show that the spin-current polarization and the spin accumulation attenuation
in the vicinity of the spin absorber must to be precisely taken into account
for accurate estimation of $\lambda_{A}$. We propose an analytical model
supported by numerical calculations that allows to extract proper $\lambda_{A}$
values of spin Hall effect materials.
