Fig. 7.

Spectra of specific energy for spherical targets from ²³⁹Pu alpha particles. The center of the sphere is placed at a distance d (µm) from the surface and the plane source of radioactivity is displaced by b (µm) into the bone volume (erg g⁻¹ = 10⁻⁴ Gy).

Reprinted from Polig (1983a) with permission of Springer Nature