Spectroscopic separation of Čerenkov radiation in high-resolution radiation fiber dosimeters.
We have investigated Čerenkov radiation generated in phosphor-based optical fiber dosimeters irradiated with clinical electron beams. We fabricated two high-spatial resolution fiber-optic probes, with 200 and 400 μm core diameters, composed of terbium-based phosphor tips. A generalizable spectroscopic method was used to separate Čerenkov radiation from the transmitted signal by the fiber based on the assumption that the recorded signal is a linear superposition of two basis spectra: characteristic luminescence of the phosphor medium and Čerenkov radiation. We performed Monte Carlo simulations of the Čerenkov radiation generated in the fiber and found a strong dependence of the recorded Čerenkov radiation on the numerical aperture of the fiber at shallow phantom depths; however, beyond the depth of maximum dose that dependency is minimal. The simulation results agree with the experimental results for Čerenkov radiation generated in fibers. The spectroscopic technique used in this work can be used for development of high-spatial resolution fiber micro dosimeters and for optical characterization of various scintillating materials, such as phosphor nanoparticles, in ionizing radiation fields of high energy.
University of Pennsylvania, Department of Radiation Oncology, 3400 Civic Center Boulevard, Philadelphia, Pennsylvania 19104, United States.
Arash
A
Darafsheh
Dartmouth College, Department of Physics and Astronomy, Hanover, New Hampshire 03755, United States.
Rongxiao
R
Zhang
Dartmouth College, Thayer School of Engineering, Hanover, New Hampshire 03755, United States.
Stephen Chad
SC
Kanick
Dartmouth College, Department of Physics and Astronomy, Hanover, New Hampshire 03755, United StatescDartmouth College, Thayer School of Engineering, Hanover, New Hampshire 03755, United States.
Brian W
BW
Pogue
University of Pennsylvania, Department of Radiation Oncology, 3400 Civic Center Boulevard, Philadelphia, Pennsylvania 19104, United States.
Jarod C
JC
Finlay
D003198:Computer Simulation; D005336:Fiber Optic Technology / Q000295:instrumentation*; D009010:Monte Carlo Method; D055100:Optical Fibers; D011839:Radiation, Ionizing; D011874:Radiometry / Q000295:instrumentation*; D013057:Spectrum Analysis