JPS5821580A - Two-dimensional radiation detector - Google Patents

Abstract

PURPOSE:To absorb the difference in the area between a group of scintillator film units expanding two-dimensionally and a light detector dispensing with taper-shaped fiber by interposing matching resin bodies for optical coupling between the phosphorous light output side of the group of the scintillator film sections and a group of optical fibers. CONSTITUTION:A solid scintillator film body 1' expanding two-dimensionally is divided with grooves 8 and 9 cut from both surfaces to form a group 10 of scintillator units. A truncated-cone-shaped matching resin bodies 12 are connected to the expanded bottom surface thereof in each zone on the output side thereof to form groups of matching resin bodies 12. The input side of an optical fiber 4' is connected to the narrowed ends of respective matching resin bodies 12. This eliminates the need for tapered formation of the optical fibers. The group 4' of the optical fibers is connected to the output end of the light detector 3.

Description

[Detailed description of the invention] This invention relates to a two-dimensional emissive layer detector.

A current example of a two-dimensional radiation detector is shown in the layout diagram in FIG. This device is constructed for the purpose of measuring two-dimensional or one-dimensional intensity distribution of
) is emitted by Xa irradiation as indicated by arrow (2), for example, on a CCD (Charg・-Coupl・dD・
A group of optical fibers (4) is inserted for transmission to a small-area photodetector 0), which is a photodetector 0). In this optical fiber group, each fiber (4) is thick on the scintillator side,
It is narrowed on the detector side, making the whole into a Q/4 shape. Also, each fiber is composed of a core region (5) and a cladding region (6) with a lower refractive index than this core region, and each light beam 7. The transmission source is prevented from leaking to the sides from AIPA. The transmission source reaching the photodetector is converted into an electrical signal and sent to a data processor (not shown) in the direction of the arrow (7).

It is difficult to manufacture the 1-diameter device because the optical fiber is tapered in order to transmit light emitted by a large-area scintillator into a small-area 0CCDK! KL has the disadvantage of increasing the unit price.

The present invention provides an improved two-dimensional radiation detector that does not require such a tapered optical fiber and is therefore easier to manufacture and lower in unit cost. That is, the present invention comprises (1) a group of scintillator film bodies that interact with radiation to emit fluorescence or phosphorescence and are distributed two-dimensionally so that the respective emitted lights are unrelated to each other; and each scintillator film body. A group of matching resin bodies for optical coupling forming a truncated conical shape, each having its bottom connected to the output surface of the emitted light, and a group of optical fibers having their respective input ends embedded from the top side of each matching resin body. and (2) a two-dimensional radiation detector comprising a photodetector connecting the output end of each party fiber to detect the respective transmission source of the source fiber group.
The two-dimensional radiation detector according to the above item 1, wherein the scintillator film group is formed by the separation 111 drilled into the surface of the integrated scintillator film, (3)
) The two-dimensional radiation detector or a according to item 1 above, wherein the cladding region of each fiber in the fiber group is removed at the input end and only the core region is embedded in each matching resin body. Each matching resin body and scintillator film body connected corresponding to each optical fiber has a refractive index of n3.1, nl, n,
When n4~n Hatake〉 theory! 〉The two-dimensional radiation detector described in Recommendation 1 above satisfies the town's requirements.

In this invention, the scintillator film group is, for example, a scintillator film body having a thickness of approximately Q and having 5 to 2 scratches.
Dig each membrane Kr from both surfaces or from one side.
i! Ltlt L, or each scintillator film body may be independently formed and arranged on the light reflecting film surface. These scintillator film groups are made of, for example, Na
I (TEL), Cm I (TI), B14G@10H
It may be a crystalline film such as 1CdWO or ZnWO4 or a fluorescent film such as ZmClg-Ag. Each member of the matching resin body group has a truncated cone shape, the bottom surface corresponds to the divided output direction of each scintillator membrane body, and the tapered tip top surface corresponds to the unit cross section of the party fiber. It is formed by using a pre-molded synthetic resin or by applying a curable resin in a conical shape. For example, epoxy * J
3m, polyurethane resin, polystyrene resin, etc. The matching resin body has a refractive index of 9 to make it easier to input the output light! [It is assumed that the core area of each party's 7 eyelids is as secure as the core of the 7 eyelids, and only the core area of each party's 7 eyelids is embedded in this matching body. The cladding region of the optical 7-eye lens has a lower refractive index than the region A, and prevents leakage to the outside of the transmission source fiber by total reflection.

Next, an example will be described. FIG. 2 is a layout diagram of the two-dimensional radiation detector in this example. A scintillator membrane body that is integrated in two dimensions (one is divided by grooves (8) and (9) K inserted from both sides, and scintillator membrane group a
・Achieved. #(8) and (9) should have a sufficient amount of Kfij to prevent light leakage between the partitioned film bodies. On one of the radiation irradiated surfaces of this group of horses, a light reflection 1 [al, for example, a JIM Al 1 = RIM exhibition, is formed so as to prevent light emission from leaking. On the other output surface, a truncated cone-shaped matching resin body α3 is connected to the enlarged bottom surface for each divided area, and a matching resin body group a2 is connected to the output surface.
has been achieved. Optical fibers (4x0 input side) are connected to the top surface of each mating resin body AA.Therefore, these fibers do not need to be formed first, and the core area is It is embedded in the matching resin body so that the output of the Syntele/II body reaches the output end of the optical fiber group (four optical detectors (3) that detect the light transmitted by each fiber). On the photodetector side, each fiber is in contact with the paper to reduce the occupied area of the group of fibers.The photodetector (3
) is converted into an electrical signal and sent to the data processor (IIK), which is stored as an electrical signal in association with each section of the scintillator membrane, and further stored in the image display I according to the IK. The transmitted signal is read out and a radiation layer transmission image of the subject is displayed.

The refractive index of the original fiber (4 Talarad regions is ml, the core region OS fold is J, the refractive index of the "Q" resin body is 118
% scintillator film body 611 refractive index t 1147,
114~mB) Select each village so that J>nl.

For example, a NaI (Tj) scintillator body with a refractive index of about L57 as n4; 1. When using quartz fibers having a refractive index of L46 as 1 m and a refractive index of L44 as mtl, an epoxy resin with a refractive index of 1.56 (Jukubatake) is used as the matching resin body with a length of 1 m.

The optical coupling between the scintillator and the optical fiber is best when the original 7° Eyepa core region excluding the cladding region is embedded in the mating resin body and reaches the output surface of the scintillator film body. be made into Also, a scintillator film body group is formed in a divided manner, and a light reflection film is formed on the radiation irradiation surface, thereby making the intensity distribution of the measured KltL radiation, for example, xlI, highly efficient and reducing crosstalk between pixels. The truncated cone-shaped mating resin body group does not require a specially shaped fiber, and serves to absorb the area difference between the two-dimensionally enlarged scintillator film body group and the photodetector.

[Brief explanation of the drawing]

FIG. 1 is a conventional two-dimensional radiation detector layout diagram, and FIG. 2 is a two-dimensional radiation detector layout diagram of the present invention. In Fig. 2, 0 (1... scintillator film body group Qa... optical coupling matching 1s11IjI body group (4
')...Optical fiber group (3)...Photodetector (8)
% (9) Separation (6) Clad area (5) Core area agent Patent attorney Inoue - Male

Claims (1)

[Scope of Claims] (1) A scintillator film group that interacts with radiation to emit fluorescence or phosphorescence and is distributed two-dimensionally so that each emitted light is unrelated to each other, and each scintillator. A group of mating W* bodies for base coupling forming a truncated cone shape with their respective bottoms connected to the emitted light output faces of the membrane bodies, and base fibers whose respective input ends are embedded from the top face side of each matching resin body. A two-dimensional radiation detector (2) comprising: a group of optical fibers; A two-dimensional radiation detector (3) according to claim 1, characterized in that the scintillator film group is formed by a nine-separated groove that is inserted into the film from its surface. The two-dimensional radiation detection according to claim 1, characterized in that the cladding region is removed at the input end of each fiber in the fiber group, and only the core region is embedded in each matching resin body. (4) Each matching resin body and scintillator film body connected correspondingly to each optical fiber are arranged so that each refractive index of the cladding region, core region, matching resin body, and scintillator film body of the original fiber is adjusted in order. , 118.114, the two-dimensional radiation detector according to claim 1 satisfies the relationship n4~ns>recommendation>nl.