US 5,675,151 AGranted

Distribution type detector using scintillation fibers

AssigneeMitsubishi Denki Kabushiki Kaisha

InventorsToru Oka, Kazunori Ikegami

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Abstract

A distribution type detector comprises scintillation fibers identical in length to each other, an optical delay fiber having a refractive index substantially identical to those of cores and claddings of the scintillation fibers, photosensitive elements, preamplifiers, constant fraction discriminators, a time-to-pulse height converter, an analog-to-digital converter, and a multichannel pulse-height analyzer. A position where a radiation falls on its corresponding scintillation fiber, is detected based on a difference between time intervals necessary for propagation of optical pulses produced in the corresponding scintillation fiber by the radiation. Thus, even if the length of each scintillation fiber is increased, position resolution can be kept high and a measuring circuit system can be simplified.

Claims18

Dependent claims

A distribution type detector, comprising:

a scintillation fiber for generating optical pulses, which propagate in both directions of said scintillation fiber, in response to a radiation or a light pulse in a given specific wavelength region;
photosensitive elements, coupled to both ends of said scintillation fiber, for generating electrical signals in response to said optical pulses;
amplifiers, coupled to said photosensitive elements, for amplifying said electrical signals output from said photosensitive elements;
timing pulse generating circuits for outputting timing pulses based on said signals output from said amplifiers;
a time-to-pulse height converter for generating a pulse signal having a pulse height proportional to a time difference between said timing pulses, said time difference being based on the optical pulses propagated in both directions of said scintillation fiber;
an analog-to-digital converter for converting the pulse signal output from said time-to-pulse height converter into a digital signal;
a multichannel pulse-height analyzer for counting said digital signal output from said analog-to-digital converter according to a value thereof;
and
signal delaying means for creating said time difference, measurable by said time-to-pulse height converter, between the timing pulses;
said distribution type detector detecting an incident position of the radiation or the light pulse based on the time difference;
said signal delaying means comprising an optical delay fiber which is made nonreactive to the radiation or the light pulse in the specific wavelength region.

8 more elements

Dependencies are inferred from the claim text.