APPLICATION OF MOS SENSORS FOR DETERMINATION OF HYDROGEN CONTENT IN SOLIDS

A new method has been developed for determination of the hydrogen cont ent in solids. The method is based on the use of a MOS (metal-oxide-se miconductor) sensor of Pd-SiO2-Si type. Hydrogen contained in the spec imen to be analysed is extracted by a high-temperature technique, heat ing the whole of the specimen, or by evaporating a microregion of the specimen (10(-5)-10(-6) cm3) under the action of a laser radiation pul se (or electron beam) in an inert gas flow. Extracted hydrogen is tran sported to a chamber containing the MOS sensor by the flow of inert ga s. The quantity of extracted hydrogen is determined from the rate of t he MOS structure capacitance change. A unit for the determination of h ydrogen content in solids has been designed and used for the analysis of UO2 ceramic fuel samples. The unit characteristics, such as a detec tion limit of about 10(-11) g and a measurement time of about 15 s, su rpass the parameters of the conventional units used for such purposes.