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Knowledge of X-ray mass attenuation coefficients is necessary when the thick target PIXE method is applied for quantitative elemental analysis of materials. For this purpose, the X-ray mass attenuation coefficients of Veigele [Atom. Data Tables 5 (1973) 51] ave been parameterized in the photon energy range of 1–150 keV for all elements from hydrogen to plutonium ( Z = 1–94), taking into account the K-, L-, M- and N-shell absorption edge structure existing in this energy interval. This parameterization reproduces the original data of Veigele within 1%. The discrepancies existing between the Veigele data and the recent mass attenuation coefficients of Berger and Hubbell [National Bureau of Standards Internal Report NSBIR, no. 87-3597 (1987)] were compared with the experimental NBS data file [E.B. Saloman, J.H. Hubbell and J.H. Scofield, Atom. Data Nucl. Data Tables 38 (1988) 1] for the case of lead ( Z = 82). The fitted parameters were tabulated and were further used in a simple computer code generating X-ray mass attenuation coefficients for PIXE applications.

L X-ray line production cross sections for Eu, Tb and Er elements have been measured as a result of 73Li ion bombardment at energies from 4.2 to 19.6 MeV. The corresponding L1-, L2- and L3-subshell ionization cross sections have been calculated and have been compared to the predictions of the ECPSSR and SCA theories. Possible reasons for observed disagreements between experiment and theory are discussed.

Individual X-ray lines and total L-shell X-ray production cross sections for Ag, Sn, Sb, Te, Ho, Ta, W, Pt and Bi thin targets have been measured as a function of 4He-ion energy from 1.5 to 3.8 MeV. Comparison between theoretical and experimental values of individual and total L-shell cross sections and their ratios has been made and discussed. The theoretical values have been calculated in the plane-wave Born approximation including corrections for the binding energy, polarisation, Coulomb deflection, energy loss and relativistic effects (ECPSSR theory). The influence of collisionally-induced alignment on measured cross sections is discussed.

The K-shell X-ray production cross sections and Kbeta /Kalpha ratios have been measured for thin targets of Ti, Rb, Zr, Nb, Mo, Pd, Ag and Sb by protons and for thin targets of Ti, Cr, Co, Cu, Se, Rb, Zr, Nb, Mo, Pd, Ag and Sn by 4He ions over the energy range of 1.5-3.8 MeV. The ionisation cross sections were calculated using atomic K-shell fluorescence yields and compared with the plane-wave Born approximation (PWBA) modified to included the effects of relativity, increasing target electron binding energy, target electron polarisation, Coulomb deflection of the incident particle and energy-loss effects in the ionisation process, resulting in the ECPSSR theory. The universal character of K-shell ionisation cross sections is discussed. The Kbeta /Kalpha ratios are compared with theoretical predictions and with results reported by other authors.

Thin targets of Sb, Te, Ho, Ta, W, Pt and Bi have been employed and L X-ray yields have been measured as a function of proton energy from 1.5 to 3.8 MeV. From these measurements the individual and total X-ray production cross sections and their ratios have been calculated and compared with the experimental results reported by other authors and with the perturbed stationary-state plane-wave Born approximation with correction for Coulomb deflection, relativistic and energy-loss effects resulting in the ECPSSR theory of Brandt and Lapicki (1979, 1981).

Experimental L-subshell ionisation cross sections are discussed. Maps of measured cross sections in atomic number and velocity parameter coordinates are presented. A dependence of ionisation cross sections on atomic number is also discussed.

The L-X-ray production cross sections for L α1, 2 , L γ 1, 5 and L γ2, 3, 6 transitions have been measured for thin targets of nine heavy elements (Ag, Sn, Sb, Te, Ho, Ta, W, Pt and Bi) by proton and helium ion impact in the energy range 1.5 to 3.8 MeV. The ionisation cross sections for the L 1 , L 2 and L 3 subshells were extracted using fluorescence and Coster- Kronig yields of Krause and emission rates of Scofield. The influence of the uncertainties of these atomic parameters on the resulting cross sections was taken into account and discussed. The measured L-subshell ionisation cross sections were compared with results reported by other authors and with predictions of the ECPSSR theory of Brandt and Lapicki. Possible explanations for the observed discrepancies for the L 1 −, L 2 − and L-subshells are discussed.

The authors used for first time the PIXE method ("particle induced X-ray emission") for determination of the concentration of in the cerebrospinal fluid of neurological patients. In 40 hitherto examined patients with epilepsy, multiple sclerosis, extrapyramidal syndromes, Little's syndrome, Guillain-Barré syndrome, cerebral strokes, tumours of brain and spine, vasomotor headaches, neuralgia and discopathy, the concentration of the following trace elements was determined: Br, Zn, CU, Pb, Rb, Fe, Ca, K, Cl, Sr, Zr, Cr, Mn, Ni, As. The ranges of the determined concentrations in ppm units mean values and mutual relations of some elements were presented. The concentration of trace elements in cerebrospinal fluid was lower than in the tissues. The authors continue further investigations in many neurological syndromes with analysis of various clinico-laboratory correlations.