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Cross-section ratios sigma(TI)/sigma(SC) of transfer ionization (TI) to single capture (SC) of Cq+- and Oq+-He (q = 1 - 3) collisions in the energy range of 15-440 keV/u (0.8-4.2 v(Bohr)) are experimentally determined. It is shown that sigma(TI)/sigma(SC) strongly depends on the projectile velocity, and there is a maximum for E(keV/u)/q(1/2) approximate to 150. Combining the Bohr-Lindhard model and the statistical model, a theoretical estimate is presented, in reasonable agreement with the experimental data when E(keV/u)/q(1/2) > 35.

The ratios of transfer ionization (TI) to single-electron capture (SC) cross sections have been measured for the collisions of partially stripped Cq+ ions (q = 1-4) with He. The collision velocity ranges from 0.7 to 4.4v(0) (v(0) is the Bohr velocity). The projectile-ion and recoil-ion coincidence technique is used to separate the processes of TI and SC. The ratios reach the maximum when the velocity is about 3.7 v(0). This can be explained qualitatively based on the two-step mechanism. The experimental results are also compared with the results calculated using the classical trajectory Monte Carlo (CTMC) method. The CTMC results are in agreement with the experimental data basically. The discrepancies in higher velocity region are interpreted by the effective charge effect.

The energy-loss straggling for low-energetic 16O ion in Co, Ni and Lu was measured. The obtained results were compared with various theoretical predictions. The variance of foil thickness was measured by different methods and the target quality was discussed.

In this paper we report the measurements of the K x-ray relative transition probabilities as follows: K-beta/K-alpha for the atomic numbers Z = 39, 51, 62, 63, 64, 66, 67 and 68; and K-alpha2/k(alpha1), k(beta1)(1)/k(alpha1), k(beta2)(1)/k(beta1)1, and k(beta3)/k(beta2) for the atomic numbers Z = 62, 63, 64, 66, 67 and 68 as induced by protons at an energy of 3 MeV. The experimental results obtained are then compared with relativistic Hartree-Fock calculations.

The present work provides previously unpublished stopping powers for 11B and 12C ions in Co, Ni, In, Pd, Gd, Lu and Ta targets in the energy region ∼1–5 MeV. The experimental results were compared with TRIM91 and SRIM96 predictions. The experimental stopping powers for 12C in Co, Ni, In, Pd, and Ta agree with theoretical predictions within several percents, but do not agree well in Gd and Lu. In the velocity-proportional region, a linear dependence of stopping power on the velocity of projectile ion was observed. 4He energy loss was taken as the measure of the sample foil thickness and the obtained thicknesses were confirmed by low energy (

A simple model for the direct ionization and transfer ionization probabilities in A2+ +He collisions in a wide projectile energy range is proposed based on the Bohr–Lindhard model and the classical statistical model. The calculated cross sections are in satisfactory agreement with the experimental data available.

The multi-electron processes are investigated for 17.9–120 keV/u C1+, 30–323 keV/u C2+, 120–438 keV/u C3+, 287–480 keV/u C4+ incident on a helium target. The cross-section ratios of double electron (DE) process to the total of the single electron (SE) and the double electron process (i.e. SE+DE), the direct double electron (DDI) to the direct single ionization (DSI) as well as the contributions of DDI to DE and of TI to DE are measured using coincidence techniques. The energy and charge state dependences of the measured cross-section ratios are studied and discussed.

The cross section ratios of the double, triple and quadruplicate ionization to the single ionization of argon by 1.5-7.5 MeV partially stripped carbon ions are measured by using time-of-flight technique. The Auger transition and the charge exchange process in the multiple ionization of argon are studied. The ratios of cross sections of the direct multiple ionization to those of the direct single ionization are obtained by subtracting the parts of the Auger transition and the charge exchange process from the measured data. It is found that the cross section ratios of the direct multiple ionization to those of the direct single ionization are in good agreement with the predicted multi-step (ν/qeff)-2n+2 law.

The K X-ray relative transition probabilities Kb/Ka of some elements for atomic numbers 23≤Z≤33 induced by 3 MeV protons were measured. The experimental results are compared with the relativistic Hartree-Fock (RHF) calculations. Good agreements have been obtained considering the experimental error.

The classical method within the independent electron model is employed to investigate (i) charge dependences of single and double ionization for helium by various charged ions Aq+ (q = 1 – 8) at impact energies of 0.64 and 1.44MeV/u, respectively, (ii) energy dependences of transfer ionization for helium by 0.5–3 MeV/u A8,9+ ions impact. The Lenz–Jensen model of the atom is applied instead of the Bohr model of the atom, and the impact-parameter dependences are also introduced into the calculations. Satisfactory agreement is found between theoretical and experimental data.

he cross-section ratios for the double-to-single ionization of He associated with no projectile charge change ( R q , q ), single-electron capture ( R q , q -1 ) and single-electron loss ( R q , q +1 ) were measured using coincidence technique. The coincidences resulted from the signals of recoil ions and scattered projectiles. For a given incoming projectile charge state the double-to-single ionization ratios vary strongly with the outgoing reaction channel. It is found that R q , q R q , q +1 R q , q -1 . For direct ionization, R q , q is nearly independent of the incident projectile charge state. However, for ionization associated with single-electron capture and single-electron loss by the projectile, R q , q -1 and R q , q +1 depend strongly on the incident charge state of the projectile. These ionization ratios are interpreted in terms of theories of the atomic polarization effect and the screening and antiscreening effect of the electrons around the core.

Rare earth elements Tb, Er and Lu were bombarded by protons with energies of 0.2-1.2 MeV, L-subshell ionization cross sections were obtained. Experimental ionization cross sections were compared with the predictions of the ECPSSR theory.

The L -shell X -ray production cross sections of Ta, Au and Bi by proton and alpha particle projectiles and the L -subshell ionization cross sections of Nd, Dy and Ho bombarded by incident alpha particles are reported. Comparison of these results with ECPSSR calculations are also reported.

L -shell X-ray cross sections of Eu, Gd, Dy and Ho have been measured for incident 2.25–4.50 MeV Li 2+ ions. Relative intensity ratios of Eu are reported. All the measured data are expressed graphically in terms of the energy of the projectile and compared with the predictions of ECPSSR theory. A reasonable agreement has been found.