[en] The excitation functions of the reactions ¹²C(³He,α)¹¹C and ¹²C(³He,d)¹³N have been measured in 100 to 200 keV steps in the energy region between 0.4 and 14.0 MeV considering all perceptible sources of errors. The absolute cross sections have been determined by measuring the annihilation radiation of positron emitting nuclei produced during the irradiation. The precision of the determination is in the order of 10%. (orig.)

[en] The RBS technique and ¹⁹F(p, αγ)¹⁶O resonance nuclear reaction at 872.1 keV, with Γ=4.2 keV, were used to measure the depth profiles of implanted ⁷⁹Br, ¹³²Xe and ¹⁹F in silicon samples. A special convolution procedure was used to extract the depth profiles from the RBS spectra and the experimental excitation yield curves. The range parameters, R_p and ΔR_p obtained in this experiment were compared with theoretical calculations. (orig.)

[en] A simple nuclear track technique has been described to measure energy-loss rate of any heavy ion in any medium. Here we present the results obtained from our measurements of energy-loss rate of 17.0 MeV/u ¹³²Xe ions in lead using special zinc phosphate (ZnP) glass detector. The errors in measurement range from 5-10%. Experimental energy-loss data has been compared with calculated values. The significance of the results and scope of the track technique is discussed. (orig.)

[en] The production of beams of antiparticles useful for atomic-collision studies is discussed. The application of these beams in recent studies of single and multiple ionization of light atoms, as well as of the differential electron-emission cross section, is elaborated on. Finally, some future experiments with antiparticles are presented. (orig.)

[en] A variational impact parameter approach to the process of direct electronic excitation of atoms by impact of ions at intermediate velocities was shown to be very successful in predicting the saturation of cross sections when the projectile charge is increased. In the present paper, the convergence to steady results promised by the variational procedure is shown to be reasonable. Theoretical predictions stay in good agreement with experimental data in the case of excitation of Fe²⁴⁺ (1s²) impinging at 400 MeV on various dilute gases (He, N₂, Ar, Kr). (orig.)

[en] Dynamical effects which lead to differences in the cross section for single- or multi-electron removal from atoms by singly-charged particle, (e, anti e, p, anti p) impact are caused by the differences in mass and sign of the charge of the projectile. This fact, often masked by simple first order theories, has now been demonstrated both experimentally and by more appropriate and sophisticated theoretical methods. Here we summarize our recent work elucidating these effects using the classical trajectory Monte Carlo technique to examine the total cross sections, and various cross sections differential in angle and energy, for electron removal. These cross sections have been calculated for intermediate velocity (1 to 6 a.u.) collisions of e, anti e, p and anti p with H and He, and have been compared with other theoretical results and experimental measurements. (orig.)

[en] The differential cross section of the ¹⁸O(p,α)¹⁵N nuclear reaction has been calibrated at proton energies between 1700 and 1775 keV and at a detection angle of 155⁰. For the calibration, two silicon reference samples and a nickel sample were partially oxidized in enriched ¹⁸O. The absolute ¹⁸O-content in the grown oxide films is measured with RBS by direct comparison with a Bi-implanted silicon calibration standard. The measured resonance curve is fitted with a split Breit-Wigner function. The maximal cross section of the resonance at 1766 keV is found to be 135±5 mb/sr. Its width is 4.5±0.3 keV. (orig.)

[en] Boron, aluminium and gallium ions were implanted at 600 keV in a crystalline Si-(001) target for tilt angles 11.6⁰, 33.7⁰, 63⁰, 73⁰ and 83⁰. The depth profiles of the implanted impurities were measured with secondary ion mass spectrometry. These experimental data are compared with simulated impurity distributions from the Monte Carlo code MARLOWE (version 12). Projected range, lateral and longitudinal spread are discussed. (orig.)

[en] Multilayer relaxation of clean Ni(110) surface has been measured by using medium energy ion scattering (52 keV H⁺) utilizing channeling and blocking techniques with a compact medium energy electrostatic analyzer. These measurements include the first reported use of an out-of-plane scattering geometry to test consistency with the normal in-plane methods. An added advantage of out-of-plane scattering geometry is the ability to tailor the analysis to a particular surface layer relaxation structure without sacrificing good double alignment conditions. When compared with a full crystal Monte Carlo simulation, the results indicate a first layer contraction of (8.0±1.5)% and a second layer expansion of (4.0±2.0)% of the Ni(110) surface which are in excellent agreement with the recent MEIS and LEED measurements. (orig.)

[en] The kinetic energy lost by atoms ejected during sputtering has been investigated in a multiple-interaction molecular-dynamics simulation. A significant fraction of the sputtered atoms were found to lose more energy (through collisions during the ejection process) than that required to overcome the nominal surface barrier potential. This contradicts the formulation of collisional sputtering theory by Falcone in which sputtered atoms are recoils that preserve their kinetic energy during the ejection process. (orig.)