LIGHT-ELEMENT ANALYSIS WITH THE CENBG NUCLEAR MICROPROBE

In the field of light-element detection (Z < 11), the capability of th e nuclear microprobe to carry out nuclear reaction analysis offers sig nificant advantages compared with other methods. But taking into accou nt 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 l ight elements in heavy matrices. Moreover, the 8 mum beryllium window of standard X-ray detectors does not permit the PIXE measurement of li ght 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. Result s are discussed in terms of strength and limit of nuclear reactions co mpared with new possibilities of X-ray detectors following improvement s in the transmission of low energy radiation through windows.