[en] A real-time imaging system using synchrotron radiation has been constructed for phantom and animal studies on less invasive coronary angiography. The system consists of a monochromator, an x-ray image intensifier, a television camera, and data acquisition equipment. The quality of the images obtained by the energy subtraction and temporal subtraction methods is evaluated. A viewing field of 50 x 60 mm was used. The detection limit in the K-edge energy subtraction image was 0.5 mm for vessel phantoms filled with 25-fold diluted agent (14 mg/ml iodine). The sensitivity and resolution of the system make it adaptable for use in transvenous angiography

[en] A high-speed κ-edge energy subtraction imaging system using synchrotron radiation for transvenous coronary angiography research was developed. The detector was an x-ray image intensifier television with a high-speed shutter. Dual-energy images were acquired using 16.7-ms exposures with the same interval when the photon energy is changed. A catheter was inserted into the inferior vena cava or the right atrium of the animal via the femoral vein. Contrast material was injected through the catheter. Dynamic energy subtraction images clearly showed the right coronary and left main coronary arteries. The system appears suitable for transvenous coronary angiography research

[en] For intravenous coronary angiography, the authors of this paper have developed an imaging system based on iodine K-edge energy subtraction. In an animal experiment, dynamic imaging of coronary arteries was achieved with an original high-speed x-ray switching method with use of an iodine filter. A mixed-energy (higher and lower than the K edge) x-ray image was obtained without filtering, and a lower-energy image was acquired with the filter inserted. THe K-edge subtraction image was computed from these two images. An oscillating mirror optics in x-ray image intensifier TV were developed for this high-speed dual-energy imaging

[en] Heavy projectile K X-ray emission yields have been measured as a function of carbon target thickness for incident ions of 40 MeV Cl¹³⁺, 95 MeV Cl⁸⁺,¹²⁺,¹⁵⁺,¹⁶⁺,¹⁷⁺, 115 MeV Fe¹⁰⁺, 120 MeV Cu¹¹⁺, 150 MeV Cu¹³⁺ and 140 MeV Br¹²⁺. In the thin target foil region where the loss and capture process of projectile L shell electrons is not equilibrated, projectile K X-ray emission cross sections have been found to be significantly influenced by the variation of the number of projectile L shell electrons. (orig.)

[en] The purpose of the present study was to compare differences in the depiction of small vessels in tumors on microangiograms obtained with a conventional soft X-ray system and with a synchrotron radiation (SR) system, and to evaluate the microangioarchitecture of these tumors and the process of their growth neovascularization. The SR system consisted of a monochromatic X-ray source of 37.6 keV just above the K absorption edge of barium and two fluorescent-screen CCD-camera lens-coupling systems. One of the CCD systems had a 24 μm equivalent pixel size and an input field size of 24x24 mm. The other system had a 6 μm equivalent pixel size and an input field of 6x6 mm. Microangiograms using the soft X-ray system depicted small vessels (diameter 20-50 μm), but the microangioarchitecture of the tumors could not be evaluated from conventional images. The monochromatic SR system allowed depiction of small vessels with a diameter of less than 25 μm. In addition, this system allowed us to confirm the process of growth neovascularization in the tumors

[en] Four kinds of Si(Li) and a high-purity Ge x-ray detectors have been tested to measure the thicknesses of gold contact layers by comparing the response of the primary Rb-Kα x-rays with that of the induced Au-Lα x rays. Observed thicknesses ranged from 140 to 260 A. Near the x-ray energies of Au-M subshell absorption edges, the contribution of x-ray transmission through the observed gold layers to the detection efficiency is greater than or equivalent to that of the inherently attached 7.6-μm beryllium window. Hence, one must be careful in the determination of the detection efficiency in x-ray semiconductor detector when low-energy x rays of less than about 4 keV are measured

[en] Electron-induced Cu-, Ge-, Ag-K shells, and Au-L₃-shell ionization cross sections have been obtained from the measurement of Kα and Lα x-ray emission cross sections around the threshold energy. K- and L₃-shell ionization cross sections have been observed to rise as a function of ln(U/sub i/)/U/sub i/, where U/sub i/ is the ratio of electron impact energy to ionization energy. In the increasing behavior of Au-Lα and -Lβ x-ray emission cross sections with increasing impact energies, the onset of L₂- and L₁-shell ionizations have been observed at L₂- and L₁-shell ionization energies. Absolute values of Cu-, Ge-, Ag-K-shell ionization cross sections are well reproduced by the empirical formula of Green and Cosslett down to the vicinity of threshold energy

[en] Equilibrium charge state distributions have been measured for 30-110 MeV Si ions in carbon and gold foils and 25-142 MeV Cl ions in carbon foils. Obtained values of mean charge states have been well reproduced by the empirical formula by Shima et al. in both ion energy dependence and foil Z₂ dependence. Asymmetric charge state distributions are in fairly good agreement with the prediction of the chi-squared model by Baudinet-Robinet. (orig.)

[en] High spatial resolution X-ray detector is a key technology for X-ray micro-imaging. In SPring-8, visible light conversion type (CCD-based) detector is used because of its wide dynamic range and low-noise. The detectors consist of a thin fluorescent (Gd₂O₂S:Tb or Lu₂SiO₅:Ce) screen, visible light optics and CCD camera. A spatial resolution of 1μm was obtained from its point spread function with high resolution system. Some applications in micro-tomography are shown. (author)

[en] Thin self-supporting Cu targets in 11-250 μg/cm² thickness were bombarded with 50-165 MeV Cu sup(qi⁺) ions (7<=qsub(i)<=24) to investigate the target thickness dependence of inner shell vacancy production processes in the symmetric collision of Cu+Cu. Doppler-shifted projectile K X-rays were discriminated from the target K X-rays, and the projectile and target K X-ray yields were separately measrued as a function of target thickness. The K X-ray yields emitted from the projectile and the target Cu atoms are strongly dependent on the projectile initial charge state and target thickness for all the investigated collision systems of Cu sup(qi⁺)+Cu. From the observed K X-ray yields, K-shell vacancy production cross sections averaged over the target thickness t of projectile sigmasub(KV) and target sigmasup(*)sub(KV) were separately derived taking into account the fluorescence yield that can be estimated from the Ksub(α) X-ray energy shift. When the values of sigmasub(KV) and sigmasup(*)sub(KV) are extrapolated to zero foil thickness, the K shell vacancy formed in the collision has been found to be equally shared between projectile and target in a single collision. With the increase of penetration depth, however, the values of sigmasup(*)sub(KV) are greater than those of sigmasub(KV) presumably due to electron transfer of a target K electron to the projectile K vacancy. The evolution process of projectile excited states as a function of target thickness and the resulting variation of projectile and target K X-ray emissions are discussed. (orig.)