Cleaning of iron archaeological artefacts by cascaded arc plasma treatment

An effective and fast way of restoration and preservation of archaeological artefacts is described. In this method a high intensity atomic hydrogen source plasma is used which expands in a low pressure treatment vessel. By nuclear techniques the removal of chlorine and the reduction of oxides to stable forms is monitored. It proves that both hydrogen atom reduction and thermal decomposition are important. In trial experiments with artefacts from a shipwreck followed by post-treatment a successful preservation has been shown. Also the removal of the dirt crust of the excavated artefacts was greatly facilitated in the treatment