Behaviour of Am-241 on environmental surfaces and the detection of the radioluminescence signal

In a radiologic emergency, a large environmental area might be contaminated by radionuclides. To locate alpha emitters remotely, the project RemoteALPHA developed an optical detection system, able to measure radioluminescence photons. In this study, we chose 241Am-doped ivy leaves, pine needles and concrete as examples representing contaminations in natural and urban areas, respectively. Measurement data was compared to the applied activity. Particularly the concrete samples showed an unexpected behaviour, because the number of photons did not rise linearly with increasing activity. We explained these apparent inconsistencies by modelling and experimentally confirming energy loss and self-shielding effects in concrete.