| 摘要 |
PROBLEM TO BE SOLVED: To accurately detect particularly aβ-ray by reducing thickness, size and position dependence and improving sensitivity. SOLUTION: A plurality of shift fibers 2 are disposed symmetrically along a peripheral edge of a scintillator 21. A photodetector 23 is mounted at a lengthwise direction end face of each fiber 22, and a reflector 24 for returning the light into the fiber is provided at the other end face. Reflectors 22a, 25 for reflecting lights toward inward of the scintillator are provided on an outer surface of the fiber 22 in non-contact with the paired scintillators and an outer surface of a peripheral edge of the scintillator provided with no fiber. Substance having smaller refractive index than that of the scintillator is disposed on a flat surface of the scintillator, and its outside of the surface is covered with a reflecting and shielding material for reflecting the light output from the scintillator inward the scintillator and shielding the light from an exterior.
|
