Laplace Transform pair model to determine bremsstrahlung spectra from attenuation data

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1984

OSTI ID:5793007

Archer, B R

This investigation presents a mathematical pair model, grounded in physical reality by the Laplace Transformation, to describe the attenuation of a photon beam and the corresponding bremsstrahlung spectral distribution. In addition the Laplace model has been mathematically extended to include characteristic radiation in a physically meaningful way. A method to determine the fraction of characteristic radiation in any diagnostic x-ray beam was introduced for use with the extended model. This work has examined the reconstructive capability of the Laplace pair model for a photon beam range of from 50 kVp to 25 MV, using both theoretical and experimental methods. In the diagnostic region, excellent agreement between a wide variety of experimental spectra and those reconstructed with the Laplace model was obtained when the atomic composition of the attenuators was accurately known. The model successfully reproduced a 2 MV spectrum but demonstrated difficulty in accurately reconstructing orthovoltage and 6 MV spectra. The 25 MV spectrum was successfully reconstructed although poor agreement with the spectrum obtained by Levy was found.

• Research Organization: Texas Univ., Houston (USA). School of Public Health
• OSTI ID: 5793007
• Country of Publication: United States
• Language: English

Related Subjects

654001* -- Radiation & Shielding Physics-- Radiation Physics
Shielding Calculations & Experiments
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ATTENUATION
BREMSSTRAHLUNG
ELECTROMAGNETIC RADIATION
ENERGY RANGE
INTEGRAL TRANSFORMATIONS
KEV RANGE
LAPLACE TRANSFORMATION
MATHEMATICAL MODELS
MEV RANGE
NEUTRAL-PARTICLE TRANSPORT
PHOTON TRANSPORT
RADIATION TRANSPORT
RADIATIONS
SPECTRA
TRANSFORMATIONS
X-RAY SPECTRA