Penetration Ionization Chamber

Abstract

A penetration ionization chamber includes a chamber, two outer electrode plates and a center electrode plate. The center electrode plate is disposed at the center of the chamber, and signals produced in the chamber can be collected completely by the center electrode plate to avoid signal losses and improve the accuracy of the test result of the ionization chamber. The center electrode plate also can maintain a constant internal volume of the chamber and prevent a change of effective volume within the chamber due to a change of electric field and enhance the stability of the test result of the ionization chamber. A protection electrode is wrapped by an insulation pin of the electrode and the outer insulation ring to form an insulation shield that can greatly reduce current leakage of the protection electrode and improve the accuracy of the test result of the ionization chamber.

Description

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is an exploded view of a preferred embodiment of the present invention;

FIG. 2 is a perspective view of FIG. 1;

FIG. 3 is a cross-sectional view of FIG. 2;

FIG. 4 is a bottom view of an internal structure of a support pin;

FIG. 5 is a bottom view of an internal structure of a signal pin;

FIG. 6 is a schematic view of an application of a preferred embodiment of the present invention;

FIG. 7 is a schematic view of a structure of a traditional penetration ionization chamber; and

FIG. 8 is a cross-sectional view of a second electrode plate as depicted in FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The structure and its connecting relation of the present invention will now be described in more detail hereinafter with reference to the accompanying drawings that show various embodiments of the invention as follows.

Referring to FIGS. 1 to 5 respectively for an exploded view of a preferred embodiment, a perspective view of a preferred embodiment, a cross-sectional view of a preferred embodiment, a bottom view of the internal structure of a support pin, and a bottom view of the internal structure of a signal pin in accordance with the present invention, a penetration ionization chamber 1 of the invention comprises a chamber 11, two outer electrode plates 12 and a center electrode plate 13.

The chamber 11 is a cylindrical hollow body made of an electric conducting metal which could be aluminum, copper, iron or one of their combinations. The chamber 11 has a plurality of support pins 111 and a signal pin 112 protruded from the internal wall of the chamber 11. The two outer electrode plates 12 are fixed respectively onto the upper and lower sides of the chamber 11 and made of a plastic material such as a polystyrene film. A side of the chamber 1 is coated with graphite to define a first electric conducting portion 121. The center electrode plate 13 is fixed in the chamber 11 for collecting ionization signals in the chamber 11 and made of a plastic material, and the whole surface of the center electrode plate 13 is coated with graphite to define a conductor of a second electric conducting portion 131.

The support pin 111 and the signal pin 112 separately have an end fixed to the chamber, and another end have a slot 1111, 1121 for holding the center electrode plate 13, wherein the support pin 111 comprises a protection electrode 1112, an electrode insulation pin 1113 and an outer insulation ring 1114, and the protection electrode 1112 is made of a metal such as aluminum, copper, iron, or their combinations and both ends of the protection electrode 1112 are wrapped by the electrode insulation pin 1113 and the outer insulation ring 1114 to define an insulation shield for greatly reducing the current leakage of the protection electrode 1112. Further, the signal pin 112 has a signal line 1122 electrically coupled to the center electrode plate 13 for outputting ionization signals in the chamber 11, and the external edge of the signal line is wrapped sequentially by an inner insulation ring 1123, a protection electrode ring 1124 and an outer insulation ring 1125, and these three layers of insulators can lower the possibility of a current leakage.

Further, the center electrode plate 13 is clamped by the slots 1111, 1121 of the support pin 111 and the signal pin 112 and fixed into the chamber 11 and disposed equidistantly from the two outer electrode plates 12. In other words, the center electrode plate 13 is installed at an interval of the same height and parallelly between the two outer electrode plates 12. The two outer electrode plates 12 are fixed respectively onto both upper and lower sides of the chamber 11 by screws, and the thickness of the two outer electrode plates is determined by the measured intensity of radiation, and factors such as blocking the output beams, changing the spectrum or losing the electron equilibrium should be taken into consideration. These factors are prior arts, and thus will not be described here.

Referring to FIG. 6 for a schematic view of an application of a preferred embodiment of the present invention, the penetration ionization chamber should be installed before its use. Firstly, the signal pin 112 of the penetration ionization chamber 1 is connected to an electrometer 2 for supplying a high DC voltage source (V), and both of the center electrode plate and the protection electrode of the ionization chamber 1 are connected to the high DC voltage source (V) at the same time to maintain the same electric potential. Ion beams are projected from an ion beam device (not shown in the figure) to the ionization chamber 1, and the ionization radiation (R) emitted from the ion beams will ionize the air in the chamber, and the high DC voltage source (V) will separate anions and cations in the chamber to produce an ionization current (I) and pass the ionization current (I) to an input terminal of the electrometer 2 and a charge capacitor (C), and an output terminal of the electrometer 2 will receive a voltage output (Vo) for determining the intensity of the ionization radiation (R) emitted by the irradiation device.

In summation of the description above, the center electrode plate is installed in the chamber, and thus the ionization signals produced in the chamber can be collected completely by the center electrode plate. The invention not only avoids a signal loss, but also improves the accuracy of the test result of the ionization chamber. On the other hand, the center electrode plate can maintain a constant volume in the chamber and improve the stability of the test result of the ionization chamber by avoiding a change of the electric field and a change of the effective volume in the chamber. Further, the protection electrode is wrapped by the electrode insulation pin and the outer insulation ring, so that an excellent insulation shield is formed between both ends of the protection electrode and the center electrode plate to greatly reduce the possibility of a current leakage of the protection electrode. Such arrangement also can improve the accuracy of the test result of the ionization chamber.

In summation of the above description, the present invention herein enhances the performance than the conventional structure and further complies with the patent application requirements. While the invention has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the invention set forth in the claims.

Claims

1. A penetration ionization chamber, comprising: a chamber, being a hollow body made of an electric conducting metal, and having a plurality of support pins and a signal pin protruded from an internal wall of said chamber;two outer electrode plates, fixed to upper and lower sides of said chamber respectively, and each having a first electric conducting portion disposed on a side of said two outer electrode plates and facing said chamber; anda center electrode plate, fixed in said chamber, and having a second electric conducting portion, for collecting an ionization signal in said chamber.

2. The penetration ionization chamber of claim 1, wherein said electric conducting metal is one selected from the collection of aluminum, copper, iron, and their combination.

3. The penetration ionization chamber of claim 1, wherein said two outer electrode plates are made of plastic.

4. The penetration ionization chamber of claim 1, wherein said first electric conducting portion is made of graphite.

5. The penetration ionization chamber of claim 1, wherein said center electrode plate is made of plastic.

6. The penetration ionization chamber of claim 1, wherein said second electric conducting portion is made of graphite.

7. The penetration ionization chamber of claim 1, wherein said center electrode plate and said two outer electrode plates are disposed equidistantly with each other.

8. The penetration ionization chamber of claim 1, wherein said support pin further comprises a protection electrode pin and an insulator.

9. The penetration ionization chamber of claim 8, wherein said protection electrode pin is made of metal.

10. The penetration ionization chamber of claim 9, wherein said metal is one selected from the collection of aluminum, copper, iron and their combination.