A calculation was carried out to evaluate the capabilities of Secondary X-ray Imaging (SXI), applied to human angiography. A primary photon pencil beam is rastered through the human heart, in two directions perpendicular to the primary photon beam. The signal is generated by fluorescent photons from a contrast agent, registered by a wide angle detector. One result is clearer images and a reduction of shadowing by obstructions inside the body. Sharp imaging is compatible with locally quantitative measurements, and also with pixel by pixel elemental analysis. The detector need not be position sensitive. Most of the primary beam will be scattered before they
reach the target, but unscattered primary beam remains well focused. To discriminate against scattered background, the photons have to pass through a position/momentum selector, a <i>W - Hf</i> absorber shield, and a time window. The calcualation gives the approximate energy spectrum for the scattered photons, for the photons passing through the position/momentum selector, and for those at thefar side of the absorber shield. The last two are evaluated for time windows between 1000 and 167 ps. The surviving background causes relative image intensity fluctuations of the order of a percent. The primary beam intensity required for SXI is comparable or less than the intensity needed for Iodine K-edge subtraction (KES) imaging, but for SXI the primary photon energy spread may be one or two orders higher than what is needed for KES. Therefore, the requirements on the primary photon source an be relaxed. With an undulator as source, monochromatization may not be needed. That would further reduce the cost of the photon source, which may be a small low energy electron ring.
Several methods (particle counting and sizing, (beta) -ray absorption monitoring, gravimetric measurements, microscopy) were all applied to study the airborne dust particle pollution in Budapest, at various locations and during different seasons of the year. In addition, the airborne dust particle concentration was determined at several altitudes and several locations as a function of particle size. The results obtained by different measurements demonstrate that in certain cases the measured pollution exceeded the values permitted by Hungarian health standards.