It has been established that because of long-term operations in experiments at the LHC, nanocarbon structures form on the cathodes of multiwire proportional chambers of the LHCb muon detector. The appearance of such structures is the cause of spontaneous self-sustained currents in the chambers. The current emission centers are growing due to the absorption of the gas mixture dissociation products on the copper cathode. The process occurs under normal conditions, which is unusual for nanostructures, and is not reproducible in laboratory aging tests.
Gavrilov et al. (Wed,) studied this question.