Radiation induced changes of optical, electrical and mechanical properties of glasses, dielectrics and semiconductors

This work is concerned with investigating the influence of ionizing radiation on different materials. Concretely, the change of their physical characteristics such as, the electrical resistivity, the optical density, the thermoluminescence spectra, the microhardness etc. The investigated materials are: polyethylene, glasses containing U3O8, Na2O and K2O, polyvinyl alcohol containing Ni2SO4, CoCl2, CuSO4 and Cu (CH3COO)2, polymer Pb2O3/composite, germanium sulphur alloy, synthetic and natural diamond, nickel chromium steel and silicon. Irradiation is carried out in neutron fields of 105-1014 neutron/cm2, gamma radiation in the dose range 102-106 Gy. and swift heavy ions of energy 1 MeV/amu fluence range 108 -1016 ion/cm2. The possibility of working out dosimetric devices (using the above mentioned materials) possessing accurate and well expressed metrical characteristics for detecting different sorts of radiation is investigated. The optimum conditions of using these dosimeters (under different thermodynamic conditions and absolute values of registered radiation) are determined. The process of defect formation and evolution in silicon single crystal and diamond irradiated with swift heavy ions is studied. The influence of high-energy heavy ions on the surface structure of nickel chromium steel is investigated. The formation of thermally stable conducting layers at the far depth of the boron projective range in silicon irradiated with swift boron ions is confirmed. Irradiation of nickel chromium steel with xenon ions lead to the change of the elemental composition of the irradiated surface. For the case of diamond semiconductor single crystal irradiated with high-energy xenon or krypton ions possessing energy 1 MeV/nucleon, the track formation is observed for the first time. The track formation criteria are established. A model characterizing the interaction of high-energy heavy ions with diamond is introduced. Such model is found to be applied for nickel chromium steel too