Abstract. The majority of PIXE analytical study on geosciences has used 3 MeV proton beams for excitation and these studies generally uses the K-X-rays for low Z elements and L-X-rays for high Z elements. The present study of resulting spectra of metamorphic high grade rocks like charnockite can require striping techniques to resolve interference problems between low and high Z elements on the applications of light energy-PIXE using Si (Li) detector. In all forms of X-ray analysis, including thick-target light energy-PIXE, the X-ray signal is a dependent of the ionization cross section and for low-energy protons, the cross section is high for the K shells of light elements and the L shells of heavy elements in charnockite rock providing sufficient fluorescent yield for analytical purposes. For Z > 55, 3 MeV protons cannot ionize K-shell electrons and analysis depends on the use of L-X-ray lines in charnockite rock. Such L-X-ray spectra are complicated and can be affected by interferences K-X-rays from low Z elements. The low Z elements present in the charnockite were identified by previous complementary analytical techniques, but not identified in this study due to the above PIXE experiment limitations, and also particularly due to the dimensions of Si (Li) detector because of low energy K-X-rays of the elements absorbed by the detector window. Both interferences complexity and detector efficiency can lead to difficulties and ambiguity in the interpretation of spectra of low Z charnockite composition, a problem that is exacerbated by uncertainty in relative K-X-ray line intensities of low Z elements. From this investigation, the light energy-PIXE is ideal for the analysis of low Z < 55 elements except lower K-X-rays of Z < 17 elements using K-X-ray lines without high Z elements present in charnockite samples.
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Received: 14 Nov 2020 – Discussion started: 10 Dec 2020
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This study proves how the experimental results coincide with theoretical factors of LE-PIXE in case of High Grade Metamorphic Rocks and calibration of Si (Li) detector in case of low Z elements for future research. The Experimental parameters behind the low Z elements and also the developments of the same LE-PIXE by alter the various parameters and the complementary techniques which will be required for low energy X-rays emitted from low Z.
This study proves how the experimental results coincide with theoretical factors of LE-PIXE in...