“…Petukhov, Terasawa and Török compiled reviews on the spread of the use of these type of spectrometers on HR-PIXE work until 1996. 16–18 On counting at that date there were a total of 22 laboratories using it for: (a) elemental analysis (24 references); (b) chemical state analysis (44 references) and (c) basic research (46 references). WDS systems still keep a standard rate of publication in these same areas and the more recent studies by Kavčič, 19–21 Kertész, 22 Hasegawa, 23 Maeda, 24 Tada, 25,26 Woo 27 and Cureatz, 28 to point out just a very few, are good examples.…”