JPH0613508Y2 - Radiation detector - Google Patents

Description

[Detailed Description of the Invention] (Industrial field of application) The present invention captures the emission of radiation from a plastic scintillator by a photomultiplier tube through a light guide,
The present invention relates to a radiation detector that detects the radiation.

(Prior Art) Generally, when radiation loses energy in a plastic scintillator, it emits light in an amount approximately proportional to the energy. This light is converted into a number of electrons in the photocathode of the photomultiplier tube in proportion to the amount of emitted light, the electrons are multiplied, and an output pulse proportional to the energy lost by the radiation is given. The energy information of the incident radiation can be known by further amplifying the output pulse and then analyzing the peak value.

FIG. 3 shows an enlarged cross-sectional view of the main part of a conventional radiation detector. In the figure, the radiation detector includes α rays, β rays and γ rays.
Thin film-shaped incident film 1 on which radiation such as rays is incident
And a plastic scintillator 2 for converting the incident radiation into light and a photomultiplier for the light (FIG. 1)
A light guide 3 for guiding 4 is arranged. Between the incident film 1 and the plastic scintillator 2 and between the plastic scintillator 2 and the light guide 3,
Adhesives 6 and 6A intervene. The adhesives 6 and 6A have the purpose of respectively adhering the incident film 1 and the light guide 3 to the plastic scintillator 2 and the frame plate 7 provided on the outer edge of the scintillator 2 and for shielding light from the outside. To do. In addition, 8 is a holding plate.

(Problems to be solved by the invention) However, between the incident film 1 and the plastic scintillator 2 or between the plastic scintillator 2 and the light guide 3.
If the incident film 1 or the plastic scintillator 2 is accidentally damaged due to the adhesive 6 and 6A, the replacement work of the incident film 1 or the plastic scintillator 2 is required. It is necessary to carefully remove the adhesives 6 and 6A without damaging the scintillator 2, and there is a drawback in that a special specialized removal technique and a great amount of replacement time are required for this purpose.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to effectively solve the problems of the prior art, to provide a radiation detector that can be easily replaced and can be replaced in a short time.

(Means for Solving the Problems) In order to achieve such an object, the present invention provides a flexible packing between at least one of an incident film and a plastic scintillator or between the plastic scintillator and a light guide. It is characterized by including.

(Operation) By such a technical means, the light shielding function by the conventional adhesive is realized by the flexible packing, and the entrance window and the plastic scintillator can be attached and detached and replaced very easily.

(Example) Next, the Example of this invention is described in detail based on drawing.

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention, and FIG. 2 is a first diagram.
The expanded sectional view of the principal part of a figure is shown. 1 and 2, parts having the same functions as those in FIG. 3 are designated by the same reference numerals. The radiation detector 20 includes a main body case 1
0, mainly the incident film 1, the plastic scintillator 2, the ride guide 3, which are housed in the main body case 10,
It is composed of a photomultiplier tube 4 and a multiplication circuit 5.

As shown in FIG. 2, the entrance film 1 and the pressing plate 8 are attached to the frame plate 7 via a flexible packing (for example, sponge-like packing) 9, and the plastic scintillator 2 and the frame plate 7 are made of the flexible packing 9A. It is attached to the light guide 3 via. Therefore, the conventional adhesive 6,6A
The light-shielding function by means of such soft packing 9,9A
If the incident film 1 or the plastic scintillator 2 is accidentally damaged by anyone, it is possible for anyone to damage the incident film 1 or the plastic scintillator 2 without replacement by a worker having special expertise. Without, it can be easily attached / detached / replaced.

It should be noted that the flexible packing 9 or 9A is provided only on either the incident film 1 and the plastic scintillator 2 or the plastic scintillator 2 and the light guide 3.
It may be possible to facilitate attachment / detachment / replacement by interposing.

(Effects of the Invention) As described above, according to the present invention, a soft material that shields external light between at least one of the incident film and the plastic scintillator or between the plastic scintillator and the light guide. By providing a flexible packing, the problems of the prior art can be effectively solved, and even if the incident film or the plastic scintillator is accidentally damaged by abolishing the adhesive used in the past, its attachment / detachment / replacement is easy. This has the effect of shortening the time.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention, and FIG. 2 is a first diagram.
FIG. 3 is an enlarged cross-sectional view of the main part of the figure, and FIG. 3 is an enlarged cross-sectional view of the main part of a conventional radiation detector. 1: incident film, 2: plastic scintillator, 3: light guide, 9,9A: soft packing, 20: radiation detector.

Claims (1)

[Scope of utility model registration request] 1. An incident film formed on a film-shaped thin film, on which radiation is incident, a plastic scintillator for converting the radiation incident through the incident film into light, a light guide for guiding the light, and In a radiation detector having a photomultiplier tube for converting light from a light guide into an electric signal and an amplifier circuit for amplifying the electric signal, between the incident film and the plastic scintillator or between the plastic scintillator and the light guide. A radiation detector, characterized in that at least one of them is provided with a soft packing that shields light from the outside.