Measurement of 60CO gamma radiation induced attenuation in multimode step-index POF at 530 nm

As optical fibres are used ever more extensively in space applications, nuclear industry, medicine and high-energy physics experiments, it has become essential to investigate the influence of ionizing radiation on their characteristics. In this work, the radiation-induced attenuation at 530 nm is investigated experimentally in step-index multimode polymethyl-methacrylate plastic optical fibres exposed to low dose-rate gamma radiation. Cumulative doses ranged from 50 Gy to 500 Gy. The radiation induced attenuation has been empirically found to obey the power law RIA= aDb, where D is the total radiation dose and a and b are the constants determined by fitting

Influence on Cr and Ni doping on PbTe local structural properties

Structural aspects of Cr and Ni incorporation into the PbTe lattice are studied by means of Extended X-ray Absorption Fine Structure (EXAFS). EXAFS measurements enabled to get exact information on Pb and Te local structural features and their thermal evolution. The obtained results also revealed that by distorting their local environment, impurity atoms (Cr, Ni) add to high inherent disorder already present in the host PbTe. Larger anharmonicity of the Pb-Te bond and larger atomic thermal parameters observed in PbTe(Cr, Ni) could be of interest for thermoelectronics applications since they are both expected to reduce the thermal conductivity

Influence on Cr and Ni doping on PbTe local structural properties

Structural aspects of Cr and Ni incorporation into the PbTe lattice are studied by means of Extended X-ray Absorption Fine Structure (EXAFS). EXAFS measurements enabled to get exact information on Pb and Te local structural features and their thermal evolution. The obtained results also revealed that by distorting their local environment, impurity atoms (Cr, Ni) add to high inherent disorder already present in the host PbTe. Larger anharmonicity of the Pb-Te bond and larger atomic thermal parameters observed in PbTe(Cr, Ni) could be of interest for thermoelectronics applications since they are both expected to reduce the thermal conductivity