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X-Spectrum Determination Applied to Flash Radiography

Published online by Cambridge University Press:  06 March 2019

Loïc Le dain
Affiliation:
Centre d'Etudes de Vaujours. BP N° 7 77181 - Courtry - France
Jean-Marc Dinten
Affiliation:
Centre d'Etudes de Vaujours. BP N° 7 77181 - Courtry - France
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Abstract

We propose a method, by absorption [1,2,3,4], of determination of the X-ray spectrum emitted by a flash X-ray radiography generator. This approach leads to an ill posed inverse problem very sensitive to the measures precision.

We improve the robustness of the method by introduction of a smoothness constraint on the X-ray spectrum to reconstruct. We also propose an automatic choice of the weight between the measurement and the constraint by using a cross-validation technique.

We present an application on an unusual flash X-ray radiography generator - i.e. 75 ns of duration pulse, 6.5 MeV of maximum energy, 350 Rad for dose - for which an instrument of direct measure has not yet been found.

Type
XIII. XRS Techniques and Instrumentation
Copyright
Copyright © International Centre for Diffraction Data 1991

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References

1) Gieiraing, J. R., The determination of X ray energy distributions by the absorption method, Physics Departement, Westminster Hospital, London, 1947.Google Scholar
2) Jones, D. E. A., The determination from absorption data of the distribution of X ray intensity in the continuous X ray spectrum, Physics Departement, Hammersmith and Lambeth Hospital, London country council, 1940.Google Scholar
3) Mainardy, R. T. and Raul Barrea, “X-Ray Spectrum Determination by successive Modifications of Beam intensity”, Nuclear Instruments and Methods in Physics Research, A28Q, 387391 (1989).10.1016/0168-9002(89)90938-8Google Scholar
4) Rubio, M. and Malnardi, R. T., “Determination of X-Ray Spectra using Characteristic Line Intensities from Attenuation Data”, Physics of Medical Biology, 29, 13711376 (1984).10.1088/0031-9155/29/11/005Google Scholar
5) Phillips, D. L., -A technique for the numerical solution of certain integral equations of the first kind, Argonne National Laboratory, Argonne June 1961, PP 84, 97.Google Scholar
6) Twomey, S.,- On the numerical solution of fredholm integral equations of the first kind by the inversion of the linear system produced by quadrature, U.S Weather Bureau, Washington, D.C. September 1962, pp 97, 101.10.1145/321150.321157Google Scholar
7) Wahba, G.,-Practical approximate solutions to linear operator equations when the data are noisy, S.LA.M., J.Numer. Anal., Vol 14, pp 651,677, Numero 4, Sept 1977.10.1137/0714044Google Scholar
8) Wahba, G.,-Constrained regularization for ill-posed linear operator equations, with applications in meteorology and medecine. statistical decision theory and related topics 3, vol 2, pp 383,417, 1982, Academic Press.Google Scholar