Direct alpha spectrometry for characterising hot particle properties

Non-destructive analysis methods, especially direct alpha spectrometry but also gamma ray spectrometry and scanning electron microscopy were applied to a nuclear bomb particle from the Thule accident. The use of high-resolution direct alpha spectrometry with the aid of Monte Carlo simulations was demonstrated here in order to determine the properties of this particle. In general, the information that can be obtained through direct alpha spectrometry depends on the information available a priori. For example, known elemental composition makes the assessment of particle dimensions possible even if scanning electron microscopy images are unavailable. Although direct alpha spectrometry may be applied for particle characterisation, further developments in spectrum analysis tools are necessary.