Title :
High energy X-ray computed tomography for industrial applications
Author :
Izumi, S. ; Kamata, S. ; Satoh, K. ; Miyai, H.
Author_Institution :
ERL Hitachi Ltd., Ibaraki, Japan
Abstract :
A high-energy X-ray computed tomography system with an electron linear accelerator was developed to image cross-sections of large-scale and high-density materials. An electron linear accelerator is used for the X-ray source. The maximum X-ray energy is 12 MeV and the average energy is around 4 MeV. The intensity of an X-ray fan beam passing through the test object is measured by a 15-channel detector array. CWO (CdWO/sub 4/) scintillators and photodiodes are employed for the X-ray detectors. The crosstalk noise due to scattering at X-ray photons by adjacent detectors is reduced to less than 1.6% by installing a tungsten shield between the scintillators. Extra channels are used to compensate for the baseline shift of the circuits. These techniques allowed attainment of a dynamic range of more than 85 dB and a noise level comparable to the signal amplitude of X-ray transmitted in a 420 mm-thick iron block. A spatial resolution of 0.8 mm was confirmed with an iron test piece 200 mm in diameter.<>
Keywords :
X-ray apparatus; X-ray detection and measurement; computerised tomography; scintillation counters; 12 MeV; 4 MeV; CdWO/sub 4/; X-ray detectors; X-ray fan beam; X-ray source; baseline shift; cross-sections; crosstalk noise; electron linear accelerator; high-density materials; high-energy X-ray computed tomography system; large scale materials; nondestructive evaluation; scintillators; Computed tomography; Computer industry; Electrons; Iron; Large-scale systems; Linear accelerators; Testing; X-ray detection; X-ray detectors; X-ray imaging;
Conference_Titel :
Nuclear Science Symposium and Medical Imaging Conference, 1991., Conference Record of the 1991 IEEE
Conference_Location :
Santa Fe, NM, USA
Print_ISBN :
0-7803-0513-2
DOI :
10.1109/NSSMIC.1991.259086
