CN104793229A - Radial detector - Google Patents

Abstract

The invention discloses a radiation detector, which comprises a resistance plate chamber, a scintillator and a photocathode. The resistive plate chamber includes a first electrode glass, and the photocathode is arranged on the first electrode glass. The scintillator is arranged outside the resistive plate chamber. The detector has high sensitivity for detecting rays, has a quantum enhancement function, and has the characteristics of high position resolution and low price, and can be applied to single-photon emission tomography (Single-Photon Emission Computed Tomography, SPECT) and positron emission tomography. Imaging (Positron Emission Tomography, PET) and other detector systems.

Description

Ray detector

technical field

The invention belongs to the field of radiation detection, in particular to a radiation detector.

Background technique

In single photon emission tomography (SPECT) and positron emission tomography (PET) detector systems, due to the scintillator structure, the detector has the characteristics of high detection efficiency and sensitivity to radiation, but its resolution is low.

The resistive plate chamber structure detector has high resolving power, but its sensitivity to radiation is low.

Contents of the invention

The present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, the present invention provides a radiation detector.

A radiation detector in a preferred embodiment of the present invention includes a resistive plate chamber, a scintillator, and a photocathode, the resistive plate chamber includes a first electrode glass, and the photocathode is arranged on the first electrode glass; the scintillator is provided Outside the resistive plate chamber.

In the radiation detector of the preferred embodiment of the present invention, since the scintillator has high sensitivity to radiation and high detection efficiency, and the structure of the resistive plate chamber has a strong resolution ability, the combination of the resistive plate chamber and the scintillator can realize the radiation detection of the radiation detector. High sensitivity, high resolution function. The photocathode in the detector has the function of photoelectric conversion, which can convert the ray information into electronic information. The scintillator located outside the resistive plate chamber is convenient for receiving the ray emitted from the human body, thereby improving the sensitivity and detection of the ray detector. efficiency.

In some embodiments, the photocathode is disposed inside the resistive plate chamber and is in contact with the glass surface of the first electrode.

In some embodiments, the scintillator is disposed on the first electrode glass.

In some embodiments, the resistive plate chamber further includes a second electrode glass and a carbon film, the second electrode glass is arranged inside the resistive plate chamber, and the second electrode glass and the first electrode glass parallel to each other, the carbon film is arranged on the surface of the second electrode glass away from the photocathode, the carbon film and the photocathode are respectively applied with a positive and negative voltage greater than 1000V, the first electrode glass and The resistivity of the second electrode glass at room temperature is greater than 10 ¹² Ω.cm.

Additional aspects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and comprehensible from the description of the embodiments in conjunction with the following drawings, wherein:

Fig. 1 is a schematic structural diagram of a radiation detector in a preferred embodiment of the present invention.

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

In describing the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " Orientation indicated by rear, left, right, vertical, horizontal, top, bottom, inside, outside, clockwise, counterclockwise, etc. The positional relationship is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, Therefore, it should not be construed as limiting the invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of said features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

In the description of the present invention, it should be noted that unless otherwise specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection. Connected, or integrally connected; it can be mechanically connected, or electrically connected, or can communicate with each other; it can be directly connected, or indirectly connected through an intermediary, and it can be the internal communication of two components or the interaction of two components relation. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

In the present invention, unless otherwise clearly specified and limited, a first feature being "on" or "under" a second feature may include direct contact between the first and second features, and may also include the first and second features Not in direct contact but through another characteristic contact between them. Moreover, "above", "above" and "above" the first feature on the second feature include that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature. "Below", "below" and "under" the first feature to the second feature include that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is less horizontal than the second feature.

The present invention provides a radiation detector, which will be described below with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of a radiation detector in a preferred embodiment of the present invention.

The radiation detector in the preferred embodiment of the present invention comprises a resistive plate chamber 10, a scintillator 20 and a photocathode 30, the resistive plate chamber 10 comprises a first electrode glass 101a, and the photocathode 30 is arranged on the first electrode glass 101a ; The scintillator 20 is located outside the resistive plate chamber 10 .

In the radiation detector in a preferred embodiment of the present invention, the scintillator 20 has high sensitivity to radiation and high detection efficiency, and the scintillator 20 can generate visible light after being excited by radiation. The resistive plate chamber 10 has the characteristics of strong resolution, simple structure, and low price. Combining the resistive plate chamber 10 and the scintillator 20 can realize the high sensitivity and high resolution functions of the radiation detector. , and has a simple structure and low price, and can be widely used in the field of ray detection, especially in detector systems such as single photon emission tomography (SPECT) and positron emission tomography (PET). The photocathode 30 has the function of photoelectric conversion, can receive the visible light emitted by the scintillator 20, and excite electrons, and can convert visible light information into electronic information. Since each electron is sent from the photocathode 30, the number of electrons sent from the photocathode 30 is approximately equal to the number of electrons causing the avalanche, so the resistive plate chamber added with the photocathode 30 is equivalent to a gas photomultiplier, the detector has a high photoelectron gain function. The scintillator 20 is arranged outside the resistive plate chamber 10 to facilitate receiving the radiation emitted from the human body, thereby improving the sensitivity and detection efficiency of the radiation detector.

In some embodiments, the photocathode 30 is disposed inside the resistive plate chamber 10 and is in contact with the surface of the first electrode glass 101a.

With such arrangement, the electrons generated by the excited photocathode 30 will interact with the working gas in the resistive plate chamber 10 , and the working gas will ionize to produce secondary electrons. The photocathode 30 is in contact with the surface of the first electrode glass 101a. When a voltage is applied to the photocathode 30, a voltage can be applied to the corresponding first electrode glass 101a, realizing the electrode plate in the resistive plate chamber technology. The added voltage requirements.

In some embodiments, the scintillator 20 is disposed on the first electrode glass 101a.

With such arrangement, the distance between the scintillator 20 and the photocathode 30 can be shortened, the influence of the outside world on the visible light emitted by the scintillator 20 can be reduced, and the efficiency of collecting the visible light emitted by the scintillator 20 by the photocathode 30 can be improved. , so as to further improve the detection efficiency, sensitivity and resolving power of the ray detector.

In some embodiments, the resistive plate chamber 10 is filled with working gas, and the pressure of the working gas is one atmosphere.

With such an arrangement, under the action of the electrons emitted by the photocathode 30 , the working gas ionizes more secondary electrons, forming an avalanche and increasing the induced current generated by the secondary electrons.

Further, the working gas may be gas such as freon or xenon, which can ionize secondary electrons under the action of electrons to form an avalanche.

In some embodiments, the resistive plate chamber 10 further includes a second electrode glass 101b and a carbon film 102, the second electrode glass 101b is arranged inside the resistive plate chamber 10, and the second electrode glass 101b and The first electrode glasses 101a are parallel to each other, the carbon film 102 is arranged on the surface of the second electrode glass 101b away from the photocathode 30, and the carbon film 102 and the photocathode 30 are respectively supplied with a voltage greater than 1000V. positive and negative voltages, the resistivity of the first electrode glass 101a and the second electrode glass 101b at room temperature is greater than 10 ¹² Ω.cm.

With such arrangement, an electric field can be formed between the first electrode glass 101a and the second electrode glass 101b, and under the action of the electric field, the electrons emitted by the photocathode 30 can acquire high energy, making the resistive plate chamber The working gas in 10 ionizes secondary electrons to form an avalanche.

In some embodiments, the resistive plate chamber 10 further includes a readout circuit board 104 and an electronic circuit 105, and the readout circuit board 104 and the electronic circuit 105 are sequentially arranged on the carbon film 102 away from the on the surface of the photocathode 30.

With such arrangement, the readout circuit board 104 can induce the current formed by the secondary electrons, and the induced current can be amplified and screened by the electronic circuit 105 to obtain the energy and intensity information of the incident radiation.

In some embodiments, the outer casing of the resistive plate chamber 10 is a sealed box 106, and a sealed insulating block 107 is arranged between the sealed box 106 and the first electrode glass 101a, so that the resistive plate chamber can 10 is a completely sealed cavity, which can prevent the working gas in the resistive plate chamber 10 from leaking, thereby affecting the working performance of the radiation detector.

An insulating film 102, such as a Mylar film, is provided between the carbon film 102 and the readout circuit board 104, which can prevent the readout circuit board 104 from being in direct contact with high voltage and prevent the readout circuit board 104 from being damaged.

The specific working principle of the detector is as follows: the working gas is sealed in the resistive plate chamber 10, and the first electrode glass 101a and the second electrode glass 101b in the resistive plate chamber 10 are arranged parallel to each other . Positive and negative high voltages are applied to the carbon film 102 and the photocathode 30 respectively. Under the action of the high voltage, a strong electric field is formed in the gas space in the detector, and the field strength in the gas can reach 10 ⁴ V /cm above. When a person checks the body, the rays emitted from the tissues and organs of the human body hit the scintillator 20 of the detector, the scintillator 20 is excited to emit visible light, and the visible light emits electrons on the photocathode 30, and the electrons are emitted in a strong Accelerated under the action of an electric field to obtain high enough energy, the electrons will interact with gas molecules and ionize secondary electrons. Under the action of the electric field, the ionized secondary electrons form an avalanche in the gas, one electron will generate 10 ⁷ -10 ⁸ secondary electrons, and the secondary electrons will be on the readout circuit board 104 during the movement to the anode A current is induced, and the induced current is amplified and screened by the electronic circuit 105 for digital processing, so as to obtain energy and intensity information of the incident radiation.

In the description of this specification, reference to the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific examples", or "some examples" etc. A specific feature, structure, material, or characteristic described in an embodiment or an example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the described specific features, structures, materials or characteristics may be combined in any suitable manner in any one or more embodiments or examples.

Although the embodiments of the present invention have been shown and described, those skilled in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the invention is defined by the claims and their equivalents.

Claims (4)

1. a ray detector, is characterized in that comprising resistive plate room, scintillator and photocathode, and described resistive plate room comprises the first electrode glass, and described photocathode is located on described first electrode glass; Described scintillator is located at described resistive plate outdoor.

2. ray detector as claimed in claim 1, it is characterized in that, described photocathode is located at resistive plate chamber interior, and with described first electrode glass surface contact.

3. ray detector as claimed in claim 1, it is characterized in that, described scintillator is arranged on described first electrode glass.

4. ray detector as claimed in claim 1, it is characterized in that, described resistive plate room also comprises the second electrode glass and carbon film, described resistive plate chamber interior is located at by described second electrode glass, described second electrode glass and described first electrode glass are parallel to each other, described carbon film is located on the surface of described second electrode glass away from described photocathode, described carbon film and described photocathode are added with the generating positive and negative voltage being greater than 1000V respectively, and the resistivity under described first electrode glass and described second electrode glass normal temperature is greater than 10 ¹²Ω .cm.