Development of a wavelength-separated type scintillator with optical fiber (SOF) dosimeter to compensate for the Cerenkov radiation effect.
Bottom Line: The scintillator of the current SOF dosimeter is a 1-mm diameter hemisphere.A dichroic mirror was used for separating input light signals.Individual signal counting was performed for high- and low-wavelength light signals.
Affiliation: Department of Medical Physics and Engineering, Graduate School of Medicine, Hokkaido University, N-15 W-7 Kita-ku, Sapporo Hokkaido, 060-8638, Japan firstname.lastname@example.org.Show MeSH
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Mentions: Figure 2 shows photographs of the wavelength-separated type SOF (WS-SOF) dosimeter used in this study. A dichroic mirror was placed facing at 45° from the optical fiber axis. As shown in Fig. 2, signals reflected by the dichroic mirror were defined as Ch1, while signals transparent through the dichroic mirror were defined as Ch2. Ch1 and Ch2 consist of the sum of scintillation signals CSc and Cerenkov signals CCere with some scale factors. A pair of the H7155 photon counting heads detect separated light signals. The scintillation spectrum of the BC490 plastic scintillator and Cerenkov radiation generated by 192Ir is shown in Fig. 3. The plastic scintillator has a peak wavelength at 420 nm, whereas the spectrum of Cerenkov radiation varies over a wide range in the visible spectrum. Since these two spectra are quite different, we tried to distinguish contributions from them separately by using a dichroic mirror, setting an adequate threshold wavelength (λth).Fig. 2.
Affiliation: Department of Medical Physics and Engineering, Graduate School of Medicine, Hokkaido University, N-15 W-7 Kita-ku, Sapporo Hokkaido, 060-8638, Japan email@example.com.