title: Application of a Laplace transform pair model for high-energy x-ray spectral reconstruction.
abstract: A Laplace transform pair model, previously shown to accurately reconstruct x-ray spectra at diagnostic energies, has been applied to megavoltage energy beams. The inverse Laplace transforms of 2-, 6-, and 25-MV attenuation curves were evaluated to determine the energy spectra of these beams. The 2-MV data indicate that the model can reliably reconstruct spectra in the low megavoltage range. Experimental limitations in acquiring the 6-MV transmission data demonstrate the sensitivity of the model to systematic experimental error. The 25-MV data result in a physically realistic approximation of the present spectrum.
mesh_terms: D006801:Humans; D008433:Mathematics; D008962:Models, Theoretical; D010315:Particle Accelerators; D011882:Radiotherapy, High-Energy / Q000379:methods*; D014965:X-Rays