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Energy Spectrum Measurement of High Power and High Energy (6 and 9 MeV) Pulsed X-ray Source for Industrial Use

  • Received : 2015.07.17
  • Accepted : 2016.06.13
  • Published : 2016.06.30

Abstract

Background: Industrial X-ray CT system is normally applied to non-destructive testing (NDT) for industrial product made from metal. Furthermore there are some special CT systems, which have an ability to inspect nuclear fuel assemblies or rocket motors, using high power and high energy (more than 6 MeV) pulsed X-ray source. In these case, pulsed X-ray are produced by the electron linear accelerator, and a huge number of photons with a wide energy spectrum are produced within a very short period. Consequently, it is difficult to measure the X-ray energy spectrum for such accelerator-based X-ray sources using simple spectrometry. Due to this difficulty, unexpected images and artifacts which lead to incorrect density information and dimensions of specimens cannot be avoided in CT images. For getting highly precise CT images, it is important to know the precise energy spectrum of emitted X-rays. Materials and Methods: In order to realize it we investigated a new approach utilizing the Bayesian estimation method combined with an attenuation curve measurement using step shaped attenuation material. This method was validated by precise measurement of energy spectrum from a 1 MeV electron accelerator. In this study, to extend the applicable X-ray energy range we tried to measure energy spectra of X-ray sources from 6 and 9 MeV linear accelerators by using the recently developed method. Results and Discussion: In this study, an attenuation curves are measured by using a step-shaped attenuation materials of aluminum and steel individually, and the each X-ray spectrum is reconstructed from the measured attenuation curve by the spectrum type Bayesian estimation method. Conclusion: The obtained result shows good agreement with simulated spectra, and the presently developed technique is adaptable for high energy X-ray source more than 6 MeV.

References

  1. Waggener RG, Blough MM, Terry JA, Chen D, Lee NE, Zhang S, McDavid WD. X-ray spectra estimation using attenuation measurement from 25 kVp to 18 MV. Med. Phys. 1999;26:1269-1278. https://doi.org/10.1118/1.598622
  2. Iwasaki A, Kubota M, Hirota J, Fujimoto A, Suzuki K, Aoki M, Abe Y. Characteristic features of a high-energy x-ray spectra estimation method based on the Waggener iterative perturbation principle. Med. Phys. 2006;33:4056-4063. https://doi.org/10.1118/1.2359227
  3. Kanno I, Imamura R, Mikami K, Uesaka A, Hashimoto M, Ohtaka M, Ara K , Nomiya S, Onabe H. A current-mode detector for unfolding X-ray energy distribution. J. Nucl. Sci. Technol. 2008;45(11):1165-1170. https://doi.org/10.1080/18811248.2008.9711905
  4. Takagi H, Murata I. Development of precise energy spectrum measurement technique for high power pulsed X-ray sources for industrial use. J. Nucl. Sci. Technol. 2016;53(6):766-773. https://doi.org/10.1080/00223131.2015.1072066
  5. Hirayama H, Namito Y, Bielajew AF, Wilderman SJ, Nelson WR. The EGS5 code system. 2006;SLAC-R-730:1-436
  6. Iwasaki S. A new approach for unfolding PHA problems based only on the Bayes' theorem. 9th International Symposium on Reactor Dosimetry. Prague Czech. September 2-6, 1996.
  7. Takagi H, Terada Y, Murata I, Takahashi A. Measurement of double differential cross section of charged particle emission reactions by incident DT neutrons - correction for energy loss of charged particle in sample materials. Symposium on Nuclear Data. Tokai Japan. November 18-19, 1999.
  8. Nauchi Y, et al. Measurements of hydrogen and helium isotopes emission spectra from neutrons induced reaction at ten's of MeV. Symposium on Nuclear Data. Tokai Japan. November 19-20, 1998.
  9. Kondo K, Murata I, Ochiai K, Kubota N, Miyamaru H, Konno C, Nishitani T. Measurement and analysis of neutron-induced alpha particle emission double-differential cross section of carbon at 14.2MeV. J. Nucl. Sci. Technol. 2008;45: 103-115. https://doi.org/10.1080/18811248.2008.9711420
  10. Nauchi Y, Iwasaki S. Convergence of unfolded spectrum with response function for single radiation based on Bayes' theorem. Nucl. Instrum. Methods. 2014;A735:437-443.