We report on high energy resolution measurements of the Kα hypersatellite x-ray spectra of Ca, V, Fe and Cu induced by impact with 144 MeV C and 180 MeV Ne ions.

The double 1s ionization of Si induced in collisions with protons and heavier ions (C, Ne) was studied by measuring the K X-ray emission of a solid Si target. In order to resolve the hypersatellite contributions in the spectra, high-resolution crystal diffractometry was employed yielding subelectronvolt energy resolution. Experimentally obtained hypersatellite yields were used to determine the double to single K shell ionization cross-section ratios σKK/σK corresponding to the investigated collisions. The experimental ratios for collisions with heavy ions, where direct Coulomb ionization and electron capture need both to be considered, were compared to the theoretical values calculated within the independent electron approximation employing single electron ionization probabilities calculated by the three body classical trajectory Monte-Carlo (CTMC) method. For proton collisions where direct ionization solely contributes to 1s ionization the semiclassical approximation (SCA) was employed.

Decay schemes of Mg and Si atoms, in all possible vacancy configurations that decay via K X-ray emission, were studied to determine the correspondence (fluorescence yields) of K alpha and K beta photon yields to the initial state production yields. The K shell fluorescence yields and non-radiative decay rates of singly ionized atoms, were taken from literature, while non-radiative decay rates of multiply ionized atoms were determined using the Larkins approach.The correspondence of photon yields to the initial state production yields was written in a matrix form. The matrix was used also to determine relative yields of components contributing to single K alpha satellites or hypersatellites, and K beta photon yields from K alpha photon yields. These values are crucial to analyze properly the K alpha hypersatellite region where there is an overlap with the K beta satellites. In the K alpha satellite region, where there is no overlap, the relative yields can be used for the evaluation of the modeled lineshapes. The calculated values were evaluated on measured spectra and were found to be satisfactory. (c) 2004 Elsevier B.V. All rights reserved.

The satellite and hypersatellite K x-ray emission of a thin Mg foil and thick polycrystalline Si target bombarded by 34-MeV C and 50-MeV Ne ions was measured using high-resolution crystal diffractometry. The corresponding projectile reduced velocities v/v(K) were 1.09 and 0.92 for C ions and 1.02, 0.86 for Ne ions in case of Mg and Si targets, respectively. An energy resolution of approximately 0.5 eV enabled separation of contributions corresponding to states with different numbers of K- and L-shell vacancies. The relative intensities of satellite and hypersatellite lines were determined by fitting the measured spectra with line shapes calculated using the GRASP92 computer code. To determine the production yields of initial states from the measured x-ray yields, the total decay schemes of initial states were considered. The decay schemes were also used to determine the relative intensities of components contributing to the observed Kalpha satellites and hypersatellites and Kbeta satellite intensities. Including theoretical predictions in the fitted model is crucial to analyze properly the Kalpha hypersatellite region which overlaps the Kbeta satellites. The initial-state production yields were then used to determine the L-shell ionization probabilities and the double- to single-K-shell ionization ratio corresponding to the four investigated collisions. The experimental values were compared to the theoretical predictions obtained within the independent electron model using single-electron ionization probabilities calculated by the three-body classical trajectory Monte Carlo (CTMC) method. Since the targets used were thick enough, the equilibrium projectile charge-state distributions in the solid media were assumed. While for the double- to single-K-shell ionization ratios a satisfactory agreement was observed between the CTMC predictions and our experimental results, the L-shell ionization probabilities were found to be overestimated by the CTMC calculations by a factor of about 2.

Maximum number of particles in a 10(20) eV proton air-shower exceeds 10(11), which makes simulation of a complete shower impossible. Thus, tracking of a representative sample of particles has to be introduced. The thinning method incorporated in present simulation codes selects particles regarding only their energy and is mostly effective in the region of the shower core. However, surface detectors sample particle densities far from the shower core (greater than or equal to 100m). We developed a thinnig method based on the particle energies and weights, their distances from the core and their incident angles. With the new method the same quality as in the standard thinning is obtained in the working area of the surface detector in approximately 20 times shorter CPU time.

MCS-8 is an 8 axis motion control system for stepper motors, servo drives and a variety of special drives. Central to the controller is the Delta Tau Turbo PMAC 2 programmable multi axis controller. It incorporates a full PLC specifically designed for positioning and control functions. We have developed a layer on top of the generic and complex Turbo PMAC 2, making the MCS-8 very easy to use as a stand alone box in a control system. Software running on embedded controller can range from EPICS, SPEC to local SCADA system with an Ethernet and RS232 interfaces. MCS-8 is capable of controlling even the most complicated motion such as Stewart-Gough platform (Hexapod). Hexapod offers six degrees of freedom positioning system with sub-micrometer precision and repeatability. PMAC controller is used to calculate kinematics and EPICS for end user interface. Important features are user selectable point of rotation in space and point to point scanning of all six axes.