title: Cerenkov light spectrum in an optical fiber exposed to a photon or electron radiation therapy beam.
abstract: A Cerenkov signal is generated when energetic charged particles enter the core of an optical fiber. The Cerenkov intensity can be large enough to interfere with signals transmitted through the fiber. We determine the spectrum of the Cerenkov background signal generated in a poly(methyl methacrylate) optical fiber exposed to photon and electron therapeutic beams from a linear accelerator. This spectral measurement is relevant to discrimination of the signal from the background, as in scintillation dosimetry using optical fiber readouts. We find that the spectrum is approximated by the theoretical curve after correction for the wavelength dependent attenuation of the fiber. The spectrum does not depend significantly on the angle between the radiation beam and the axis of the fiber optic but is dependent on the depth in water at which the fiber is exposed to the beam.
authors: School of Physics, The University of Sydney, New South Wales 2006, Australia.
authors: Jamil
authors: J
authors: Lambert
authors: Yongbai
authors: Y
authors: Yin
authors: David R
authors: DR
authors: McKenzie
authors: Sue
authors: S
authors: Law
authors: Natalka
authors: N
authors: Suchowerska
mesh_terms: D016477:Artifacts; D017076:Computer-Aided Design; D004583:Electrons; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008027:Light; D055100:Optical Fibers; D017785:Photons; D020266:Radiotherapy, Conformal; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity