RESUMEN
Two methods for the feed of vapor from solid materials in the Center for Nuclear Study ECR ion source are described. A rod placed near the wall of the plasma chamber, operating up to a melting point of 2600 °C, has been used for CaO, SiO2, and FeO. An oven with a number of openings, operating up to 800 °C, has been used for P2O5, Li, and S. Typical ion beam intensities of (7)Li(2+), (6)Li(3+), (40)Ca(12+), and (56)Fe(15+) are achieved 280, 75, 28, and 7 eµA, respectively. High intensity heavy ion beams are stably supplied into the azimuthally varying field cyclotron.
RESUMEN
Atomic resolution low-angle bright-field (LABF) scanning transmission electron-microscope (STEM) images and high-angle bright-field (HABF) STEM images of [011]-orientated Si have been experimentally obtained together with high-angle annular dark-field (HAADF) STEM images. The contrast formation mechanisms of the LABF STEM and HABF STEM images are examined in comparison with HAADF STEM images. The HABF STEM images independent of defocus and thickness have spatial resolution comparable with HAADF STEM images, and are shown to be given as a simple convolution under the non-dispersion approximation of localized Bloch waves.
RESUMEN
A deconvolution processing of high-resolution high-angle annular dark field (HAADF) scanning transmission electron microscopy (STEM) images, combined with maximum entropy method, is applied to two experimental [0 11]-Si images; one having unresolved dumbbells and the other having resolved dumbbells and artificial bright spots. The deconvoluted images for these images show bright spots corresponding to the projected atomic columns and no artificial bright spots. Thus, the deconvolution processing provides almost a real projected atomic structure by eliminating effects of the probe function from HAADF STEM images.