Development of high-dose-rate quasi-x-ray laser generators and applications to medical radiographies including polycapillary radiography

点击翻译按钮获取中文摘要

Quasi-x-ray laser generator : The high-voltage main condenser is charged up to 55 kV by a power supply, and electric charges in the condenser are discharged to the tube after triggering the cathode electrode with the trigger device. The plasma flash x-rays such as laser are then produced. The x-ray tube is a demountable cold cathode triode that is connected to the turbo molecular pump with a pressure of approximately 1 mPa, and the target elements are iron, nickel, copper, molybdenum, silver, and cerium.Measurement of x-ray spectra from weakly ionized plasma : X-ray spectra from the plasma source were measured by a transmission-type spectrometer with a lithium fluoride curved crystal of 0.5 mm in thickness. The spectra were taken by a computed radiography (CR) system with a wide dynamic range, and relative x-ray intensity was calculated from Dicom digital data. In fact, we observed quite sharp lines of K-series characteristic x-rays such as lasers, while bremsstrahlung rays were hardly … More detected.Divergence by lead slits : In order to measure the difference in characteristics between x-rays from a conventional tube and these from the plasma tubes, we employed two lead slits in order to measure the divergence of the x-rays. As compared with x-rays from a conventional tube with a tungsten target, the characteristic x-rays from linear plasmas of copper and molybdenum were diffused greatly after passing through the two slits.High contrast angiography using a cerium target x-ray tube : Characteristic x-rays from a cerium target are useful to perform angiography using an iodine-based contrast medium, since the photon energies of K-series lines of cerium are slightly higher than the energy of the K-absorption edge of iodine. In angiography of a larger heart extracted from a dog, using iodine spheres, the coronary arteries were clearly visiblePolycapillary radiography : Using a plane-focus plasma x-ray tube in conjunction with a polycapillary plate, we performed quasi-monochromatic parallel radiography achieved with the CR system. Less