LIGHT-ELEMENT ANALYSIS WITH THE CENBG NUCLEAR MICROPROBE

In the field of light-element detection (Z < 11), the capability of the nuclear microprobe to carry out nuclear reaction analysis offers significant advantages compared with other methods. But taking into account the low beam current available, reactions with large cross sections must be selected in order to achieve acquisition in a reasonable time. This restriction prevents the use of RBS analysis for detection of light elements in heavy matrices. Moreover, the 8 mum beryllium window of standard X-ray detectors does not permit the PIXE measurement of light elements. We present here some examples in the use of the resonant nuclear reactions (C(p, p)C)-C-12-C-12 and (O(alpha , alpha)O)-O-16-O-16 for carbon and oxygen determination in different materials. Results are discussed in terms of strength and limit of nuclear reactions compared with new possibilities of X-ray detectors following improvements in the transmission of low energy radiation through windows.