| Autor: |
L. L. Funk, C. L. Wang, B. W. Hannan, Jason P. Hodges, M. L. Crow, Richard A. Riedel |
| Rok vydání: |
2015 |
| Předmět: |
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| Zdroj: |
2015 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC). |
| DOI: |
10.1109/nssmic.2015.7581839 |
| Popis: |
In this paper we compare the performance of grooved and flat ZnS/6LiF scintillators in a wavelength-shifting-fiber (WLSF) detector. Flat ZnS/6LiF scintillators with the thickness L=0.2−0.8 mm were characterized using photon counting and pulse-height analysis and compared to a grooved scintillator of approximately 0.8 mm thick. While a grooved scintillator considerably increases the apparent thickness of the scintillator to neutrons for a given coating thickness, we find that the flat scintillators perform better than the grooved scintillators in terms of both light yield and neutron detection efficiency. The flat 0.8-mm-thick scintillator has the highest light output, and it is 52% higher compared with a grooved scintillator of same thickness. The lower light output of the grooved scintillator as compared to the flat scintillator is consistent with the greater scintillator-WLSF separation and the much larger average emission angle of the grooved scintillator. We also find that the average light cone width, or photon travel-length as measured using time-of-flight powder diffraction of diamond and vanadium, decreases with increasing L in the range of L=0.6−0.8 mm. This result contrasts with the traditional Swank diffusion model for micro-composite scintillators, and could be explained by a decrease in photon diffusion-coefficient or an increase in micro-particle content in the flat scintillator matrix for the thicker scintillators. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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