Dr Kentaro Toh (Japan Atomic Energy Agency)
A spatial resolution of a wavelength-shifting (WLS) fibre detector coupled with a ZnS/6LiF scintillator screen was evaluated experimentally as a function of a scintillator thickness and a diametre of the WLS fibre. The spatial resolutions were measured separately with respect to the light spreading within the scintillator or within the layre of the WLS fibres. The empirical formula was derived that describes the two-dimensional spatial resolution of the detector. The test detector head comprised of two, crossly-arranged WLS fibre arrays and a single ZnS/6LiF scintillator screen that was placed on top of the top WLS fibre array. A small fraction of the scintillation light generated in the scintillator in the n(6Li,alpha)t reaction escaped from the surface of the scintillator and they were re-absorbed in the top and/or bottom WLS fibre arrays while propagating through them. The measured spatial resolution was significantly related with the thickness of the scintillator and the diamtre of the WLS fibre, suggesting that the light spreading within the scintillator and the WLS fibre arrays dominated the spatial resolution of the detector. The derived empirical formula would be useful to predict a spatial resolution of this type detector, particularly when designing and optimizing competitive detector performances such as a high spatial resolution and a high detector efficiency.
Dr Tatsuya Nakamura (Japan Atomic Energy Agency)
Dr Kaoru Sakasai (Japan Atomic Energy Agency) Mr Katsunori Honda (Japan Atomic Energy Agency) Dr Kazuhiko Soyama (Japan Atomic Energy Agency) Dr Kentaro Toh (Japan Atomic Energy Agency) Dr Masaki Katagiri (Ibaraki University)