BONE POWDER EXPOSED TO THE ACTION OF C-12 AND MG-25 ION-BEAMS AS INVESTIGATED BY ELECTRON-PARAMAGNETIC-RESONANCE SPECTROSCOPY

Bovine compact bone powder was irradiated with alpha-particles of Am-2 41, C-12(6+) and Mg-35(12+) ion beams, then examined by the e.p.r. spe ctroscopy. The stable e.p.r. signal found is of the same characteristi c as that observed in gamma-irradiated bone (g(perpendicular to) = 2.0 017, g(parallel to) = 1.9973, Delta H-pp = 0.85 mT). Thus, the structu re of radiation induced paramagnetic center in bone does not depend on the LET of radiation used. The radiolytic yields of the formation of stable paramagnetic centres in bone powder irradiated with gamma-rays are G(gamma) = 0.08 +/- 0.01 while with C-12(6+) ionbeams roughly abou t G(c) = 0.02, respectively.