Speaker
Prof.
Igor Alekseev
(Radium Khlopin Institute, Russia)
Description
Using several modes of Mossbauer spectroscopy, after effects have been studied of irradiating metallic iron with 1) thermal neutrons (fluence of 1.8∙E24 n∙m-2); 2) protons (energy, 6.0/2.0 МeV; fluence, 1.0∙E22 p∙m-2); 3) deuterons (energy, 9.0/7.3 МeV; fluence, 1.0∙E21 to 1.0∙E22 d∙m-2); 4) α-particles from a 238Pu source (energy, 5.5. MeV; fluence, 2.5∙E19 α∙m-2); 5) 12C- and 14N-ions (energy, 47.2/0 and 58.8/0 МeV, respectively; fluence, (1.6 to 8.2)∙E19 ions∙m-2); 6) 6.1 to 8.8 МeV α-particles and 208,212Pb, 212,216Po recoil nuclei from a 228Th-source (energy, 0.11 to 0.17 МeV), the total fluence being 4.5∙E18 particles∙m-2.
The experimental data obtained in the study enabled various types of external radiation to be correlated as to their radiation damage, the effect on the structure-, phase composition- and corrosion resistance properties of metallic iron.
After irradiating with neutrons, protons and weak deuterons (beam currents of less than 5 µA), it is only the magnetic superfine structure, which is characteristic of alpha-Fe, that has been observed in the experimental spectra.
Irradiation with intensive beams of deuterons (beam currents, 10 to 15 µA), α-particles , 12C- and 14N-ions leads to a structural disordering of the alpha-Fe lattice and to the emergence of the gamma-phase on the surface of foils and in the near-surface area: a single component, which is 2 to 3 times wider as compared to the magnetic sextet lines: is a result of local heating of the lattice to high temperatures with subsequent recrystallization from the “molted" volume.
Irradiation of iron foils with recoil nuclei (combined with α-particles) provokes corrosion processes and is accompanied by an intensive oxidation of the metal.
The work was supported by a grant from the Russian Foundation for Basic Research (12-08-00048).
Primary author
Prof.
Igor Alekseev
(Radium Khlopin Institute, Russia)
Co-author
Mr
Dmitry Novikov
(Radium Khlopin Institute)
