Using Atomic Force Microscopy Methods, we studied the samples of the cathodes of multiwire proportional chambers after long-term irradiation with a beta-source 90Sr at the longevity test. The changes in the morphology of the copper foil surface at the cathode of the detector as a result of the influence of the electron flow are described. It is presented a quantitative assessment and analysis of the evolution of the resulting radiation defects depending on the irradiation conditions. It is shown the similarity of the radiation defects in the laboratory prototypes and in full scale proportional chambers that have been operated at the LHC for almost 10 years.
The new results of cathode surface degradation in muon proportional chambers of CMS after a long-term irradiation with a 90Sr β-source are presented. The data of the complex analysis of the copper foil samples from the cathode are shown. The AFM method revealed the general radiation damage of the copper surface and the dynamics of its change. It is clearly demonstrated that the revealed development of the radiation erosion on the cathode is a result of electron irradiation. Moreover, the nature of erosion and level of the destruction of copper are associated with irradiation intensity. The study of the elemental and phase composition together with the data of structural analysis allowed us to single out the stages of the radiation aging of the copper surface on the cathodes and consider the processes which are at the basis of them.
High prevalence of cholelithiasis necessitates development of an easy screening diagnostic method, and therefore structural analysis of a dried drop of biological fluid attracts special attention. A new method, clinical crystallography, has been used for analysis of bile from patients with cholelithiasis. A relationship between the crystal morphology and biological fluid viscosity has been revealed.
