Investigation of radiation erosion in a gas discharge detector by atomic-force microscopy

Atomic-force microscopy methods were used to study specimens of cathodes of multiwire proportional chambers subjected to a long-term exposure to a $\beta$-source $^{90}$Sr in the course of laboratory longevity tests. The changes in the surface morphology of the copper foil at the detector cathode that have occurred as a result of action of an electron beam have been described. The quantitative estimate and analysis of the evolution of radiation defects depending on the irradiation dose are presented. The similarity of the radiation-induced defects in the laboratory prototypes and in the full-scale proportional chambers after their use for 10 years at the Large Hadron Collider is demonstrated.