SEARCHING FOR RESERVE FOR EXPANSION OF THE POSSIBILITIES TWO-ENERGY RADIOGRAPHY
Theoretical analysis and experimental studies show that the two-energy detection method not only allows one to detect organics on the background of metal, but also substantially increases (by 3-5 times) the detection ability of the system as a whole, especially if parameters of the S-PD pair are optimized, in particular, when ZnSe(Te) is used in the low-energy circuit. A possibility to distinguish, in principle, between substances with insignificant differences in atomic number has been theoretically proven – by transition to multi-energy radiography. 3Dimaging has been realized using S-PD detector arrays. Results of experimental studies of detector arrays S-PD used for X-ray digital radiography have shown that there exist further possibilities to increase spatial resolution of this system up to 2-3 line pairs per mm.
Determining chemical compositions by the method of multi-energy radiography
A theoretical model of multi-energy radiography is proposed and two approaches—“synthesis” and “analysis”—to studying the structure of objects by this method are considered. It is theoretically proved that the atomic numbers of elements and the other parameters of chemical composition of a sample can be restored from the multichannel absorption data. The multi-energy radiography approach and possible generalizations open wide prospects for both basic experimental investigations and nondestructive testing applications.
DESIGN CONSIDERATION TO PPM KLYSTRONS FOR INDUSTRIAL LINAC
Toshiba has been developing the C-band and X-band Periodic Permanent Magnet (PPM) focused klystron in collaboration with KEK and manufactured prototypes for the JLC project. [1] The PPM klystron has an advantage to enhance the total efficiency as a result of eliminating the electric power for the focusing magnet. From experience on the development the PPM focused klystrons for the JLC project, we plan to apply the PPM focused klystron to the medical and industrial linac. The periodic magnet focusing scheme has some technical difficulties such as stop band voltage. To design the PPM klystron for the medical and industrial linac, it is necessary to give heed to electron beam instability; so that the tube parameters of the PPM focused klystrons have some constraints. The size of the accelerator system is substantially reduced if a PPM focused klystron is used. The majority of medical and industrial linacs use frequencies of S-band range. We discuss the availability of the S-band PPM focused klystron in this paper.