Radiation and temperature resistant electrical contacts for ITER diagnostic components

Recent in-reactor and accelerator high temperature in vacuum irradiation testing of components for ITER has highlighted a serious problem related to the stability of electrical connections. Devices such as JET-type resistive bolometers, ferroelectric bolometers, and Hall probes have all suffered from loss of electrical connection to the component. In the present work two methods to provide a mechanically robust electrical connection between the measurement equipment and a nm-thick Pt electrical conductor tracks sputtered on an insulating substrate have been examined. The first one uses the sintering technique with subsequent protection of the contact with glazing, while the second approach is based on the use of miniature binding posts with laser-welded platinum wires. Good electrical and mechanical stability following repeated heating and ionizing (electrons and gamma) irradiation is observed.