JPH0536746U - Ionization chamber - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce the number of obstacles in the radiation transmission part and the space in a monitor that measures the radiation dose. [Structure] The collector electrode 1 is arranged at the center of the cylinder of the high-voltage electrode 2 formed in a well shape, and is independently separated into eight insulators 3,
Supported by 4. The above unit is housed in the shield case 7. [Effect] Independently separated ionization chambers are arranged on one plane, and the unit space is small.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This invention relates to the improvement of an ionization chamber for monitoring radiation such as X-rays and γ-rays.

[0002]

[Prior Art]

 FIG. 4 is a diagram for explaining the principle of the ionization chamber. This is one in which a power source 5 and an ammeter 6 are connected between the electrodes 1 and 2 facing each other. When a voltage of, for example, several 100 V is applied between the electrodes 1 and 2 by the power source 5, an ionizing current flows when the radiation 5 is incident, and the intensity of the radiation can be monitored.

FIG. 4 is a diagram showing an example of the configuration of a conventional finger-tip type ionization chamber. FIG. 4A is an external view of the configuration, which shows a total of four ionization chambers, one X-axis pair and one Y-axis pair. Are arranged in different steps. (B) is a configuration diagram of one of them, in which the electrodes 1 and 2 are coaxially arranged in the shield case 7, and these are supported by the insulating members 3 and 4. The shield case 7 is for shielding external noise and is normally grounded.

[0004]

[Problems to be solved by the device]

 Since the conventional ionization chamber is configured as described above, there is a limit in thinning the dimension in the beam transmission direction, and the ionization chamber is generally equipped with two systems in the cross to ensure safety. However, there was a problem in that if two layers were stacked on the cross, a considerable amount of space was required, and each of them had to be supported independently.

The present invention has been made in order to solve the above problems, and can simplify the holding structure, reduce the obstacles in the radiation transmitting portion, and reduce the size in the beam transmitting direction of the ionization chamber. Aim to get.

[0006]

[Means for Solving the Problems]

 The ionization chamber according to the present invention is one in which an X-axis ionization chamber and a Y-axis ionization chamber are arranged on the same plane.

[0007]

[Action]

 In the ionization chamber in this invention, the X-axis ionization chamber and the Y-axis ionization chamber are formed on one plane by sacrificing a part of the current value that can be collected in the central part, and the ionization current value in each area is set. To be able to measure.

[0008]

【Example】

 Example 1. An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, the collector electrode 1 is arranged at the center of the cylinder of the high-voltage electrode 2 formed in a well shape, and is independently separated into eight pieces and supported by the insulators 3 and 4. The above unit is housed in the shield case 7.

With such a structure, eight collecting electrodes 1 can be installed, and by combining them, the left and right X axes and the up and down Y axes can be monitored. Also, if necessary, it is possible to monitor each location on the 8 planes.

Example 2. In the above embodiment, the collector electrode 1 is divided into eight pieces, but as shown in FIG. 2, four pieces may be independently separated and arranged on one plane.

Example 3. Further, even if the collector electrode 1 separated at the cylinder center of the high voltage electrode 2 is arranged on one plane as shown in FIG. 3, the same effect as the above embodiment can be obtained depending on the conditions.

[0012]

[Effect of the device]

 As described above, according to the present invention, since the multipoles are arranged on one plane, the space in the beam transmission direction of the radiation can be small, and the multipole arrangement allows many monitoring conditions and cases. There is an effect obtained in.

[Brief description of drawings]

FIG. 1 is a sectional view of an ionization chamber according to an embodiment of the present invention.

FIG. 2 is a sectional view of an ionization chamber according to another embodiment of the present invention.

FIG. 3 is a sectional view of an ionization chamber according to another embodiment of the present invention.

FIG. 4 is a configuration external view and a cross-sectional view of a conventional ionization chamber.

[Explanation of symbols]

 1 collecting electrode 2 high voltage electrode 3 insulating member 4 insulating member 5 power supply 6 ammeter 7 shield case

Claims (1)

[Scope of utility model registration request] 1. An ionization chamber characterized in that a total of four fingertip type ionization chambers each having an independent function are arranged in a well shape in a plane, one pair of X-axis pairs and one pair of Y-axis pairs. Further, the ionization chamber is characterized in that a multi-pole ionization chamber is arranged on a plane by changing the configuration shape.