Eilenberger approach to the cutoff parameter, ξh, of the field distribution in the mixed state of high κ-superconductors is developed. It is found that normalized value of ξh/ξc2 decreases both with temperature (due to Kramer-Pesch effect) and with impurity scattering rate Γ. Our theory explains μSR experiments in some low-field superconductors and different ξh values from the Ginzburg-Landau theory predictions in isotropic s-wave superconductors. A comparison with another characteristic length ξ1, describing the gradient of the order parameter in the vortex center, is done. They have very different Γ-dependences: monotonous suppression of ξh(B) values and crossing behavior of the ξ1(B) curves at various Γ. This is explained by the nonlocal effects in the Eilenberger theory.

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