JPS623683A - Ion chamber type x-ray detector - Google Patents

Abstract

PURPOSE:To stabilize the temperature characteristic by supporting end parts of electrode plates, which are set at prescribed intervals, through an adhesive by insulator supports and exposing surfaces of insulator supports between electrode plates. CONSTITUTION:In an ion chamber type X-ray detector, two insulator supports 11 having flat surfaces support end parts of anodes 2 and cathodes 3 through an adhesive 12 and surfaces 13 between anodes 2 and cathodes 3 are exposed. Consequently, the adhesive is hardly expanded thermally, and bending of each electrode plate due to thermal expansion of the adhesive is not caused, and insulation between electrode plates is stabilized to stabilize the temperature characteristic because parts of insulator supports 11 between electrode plates are exposed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an ionization chamber type X-ray detector for a computed tomography apparatus, and more specifically, the present invention relates to an ionization chamber type The present invention relates to an ionization chamber type X-ray detector in which the edges of the plates are supported through an adhesive and the creeping surface between each electrode plate is exposed.

(Prior art) As is well known, the ionization chamber type X of the computerized tomography apparatus
The line detector has the configuration shown in FIG. In the figure, the X-ray detection system is constructed by connecting a signal electrode plate 2 (hereinafter referred to as anode) and a bias electrode plate 3 (hereinafter referred to as cathode) to incident X-rays in a sealed case 1 filled with xenon gas, etc. The electrode plate arrangement body is provided with electrode plate arrays that are arranged substantially parallel and alternately. The front part 4 of the sealed case 1 is made of a material with good X-ray transparency, such as an aluminum thin film, and serves as an X-ray entrance window (X-rays enter from arrow X). Further, the sealed case 1 has an arch shape with the X-ray entrance window 4 facing inside.

On the other hand, the anode 2 is connected to an individual current detection circuit (not shown).
Furthermore, all the cathodes 3 are connected in common to the output ends of a DC voltage source (not shown).

Note that the X-ray entrance window 4 is normally connected to a reference potential point (ground potential) of a current detection circuit or a DC voltage source.

Conventionally, the anode 2 in this type of ionization chamber type X-ray detector
and the cathode 3 as shown in FIG.
2), two ceramic insulator supports (substrates) 6 with grooves 5 spaced apart and an epoxy adhesive 7 (the adhesive 7 has a thickness of approx. .5 and covering the creeping surface 8 between the anode and cathode).

In the above configuration, when X-rays enter the X-ray detector,
The xenon gas is ionized, and an ionization current flows between the anode 2 and cathode 3 and is detected by the current detection circuit. This allows the amount of incident X-ray energy to be known.

(Problem to be solved by the invention) However, in conventional ionization chamber type X-ray detectors, the anode and cathode are bent due to the thermal expansion of the adhesive, which changes the sensitivity (temperature characteristics of sensitivity are poor). Furthermore, if the adhesive contains impurities or is poorly cured, there is a problem in that the insulation between the anode and cathode is reduced.

(Means for Solving the Problems) The present invention has been made in view of the above, and its purpose is to provide a device that has stable temperature characteristics and that does not cause deterioration in insulation between electrode plates. The present invention provides an ionization chamber type X-ray detector.

In the ionization chamber type X-ray detector of the present invention that achieves the above object, the insulator support supports the ends of the electrode plates installed at predetermined intervals through an adhesive, and The creepage surface is exposed.

(Example) Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a block diagram showing the main parts of a Lightning 111N type X-ray detector according to an embodiment of the present invention, and is a cross-sectional view of the ionization chamber type X-ray detector. In FIG. 1, two insulator supports (substrates) 11 having flat plate surfaces support the ends of an anode 2 and a cathode 3 with an adhesive 12 interposed therebetween, and provide a creeping surface between the anode and cathode. 13 is exposed (no adhesive is present).

Such alignment of the anode 2 and cathode 3 is carried out using a jig (positioning device for electrode plate alignment body) having grooves at predetermined intervals.
) is used. That is, an anode and a cathode are alternately inserted into the respective parts of the jig to form an electrode plate array consisting of an anode and a cathode. After applying a very small amount of epoxy adhesive (about 0.151 M1 thickness) to the ends of the anode and cathode to be joined to the insulator support, the insulator support is joined and integrated. When the jig is removed after the adhesive has hardened, the anode and cathode are held in the configuration shown in FIG.

In the above configuration, the creeping surface 13 between the anode and cathode
has no adhesive and the surface of the insulator support is exposed. Furthermore, only a very small amount of adhesive is present between each electrode plate and the insulator support.

Therefore, there is almost no thermal expansion of the adhesive, and almost no bending of each electrode plate due to this is observed. Furthermore, since the portions between each electrode plate in the insulator support are exposed, the insulation between them is stable.

(Effects of the Invention) As explained above, according to the ionization chamber type X-ray detector of the present invention, the insulator support supports the ends of the electrode plates installed at predetermined intervals through an adhesive. At the same time, since the structure exposes the creeping surface between each electrode plate, the temperature characteristics are stable and the insulation between the electrode plates does not deteriorate.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing the main parts of an ionization chamber type X-ray detector according to an embodiment of the present invention, FIG. 2 is a configuration diagram showing the ionization chamber type X-ray detector, and FIG. 3 is a configuration diagram showing a conventional ionization chamber type It is a block diagram which shows an example. 2... Anode, 3... Cathode, 11... Insulator support, 12... Adhesive, 13... Creeping surface.

Claims (1)

[Claims] An ionization chamber comprising an electrode plate array consisting of a large number of signal electrode plates and bias electrode plates arranged in a direction substantially parallel to the X-rays incident from the X-ray entrance window and supported by an insulator support. Type X
In the ray detector, the ionization box type line detector.