阅读说明：本技术 轻便式γ辐射定向探测器 (Portable gamma radiation directional detector ) 是由 李东臣 于 2019-09-30 设计创作，主要内容包括：一种轻便式γ辐射定向探测器,包括外壳6、主晶体7、圆柱形副晶体8、圆环形副晶体9和光电倍增管10,主晶体7为圆柱形NaI(TL)内烁晶体,圆柱形副晶体8为圆柱形CsI(TL)的烁晶体体,圆环形副晶体9为塑料圆环闪烁晶体。主晶体7、圆柱形副晶体8和圆环形副晶体9同轴安装在外壳6内的光电倍增管10的端面上。本发明减轻了γ辐射定向探测器的重量,解决了它长期未解决的苯重问题,而且提高了它的定向性能。具有结构简单轻便、设计合理、定向性能好等特点。(A portable gamma radiation directional detector comprises a shell 6, a main crystal 7, a cylindrical auxiliary crystal 8, a circular auxiliary crystal 9 and a photomultiplier tube 10, wherein the main crystal 7 is a cylindrical NaI (TL) internal scintillation crystal, the cylindrical auxiliary crystal 8 is a cylindrical CsI (TL) scintillation crystal, and the circular auxiliary crystal 9 is a plastic circular scintillation crystal. The main crystal 7, the cylindrical secondary crystal 8 and the annular secondary crystal 9 are coaxially mounted on the end face of a photomultiplier tube 10 within the housing 6. The invention reduces the weight of the gamma radiation directional detector, solves the problem of benzene weight which is not solved for a long time, and improves the directional performance of the gamma radiation directional detector. The device has the characteristics of simple and light structure, reasonable design, good orientation performance and the like.)

1. A portable gamma radiation directional detector is characterized by comprising a shell, a main crystal, a cylindrical auxiliary crystal, an annular auxiliary crystal and a photomultiplier; the main crystal cylindrical NaI (TL) inner scintillation crystal, the cylindrical auxiliary crystal is a cylindrical CsI (TL) scintillation crystal body, and the annular auxiliary crystal is a plastic annular scintillation crystal; the main crystal, the cylindrical secondary crystal and the annular secondary crystal are coaxially arranged on the end surface of the photomultiplier in the shell.

2. The portable gamma radiation directional detector of claim 1, wherein the primary crystal is a cylindrical NaI (TL) internal scintillating crystal with a 2.54cm vertical diameter and a height of 5cm, and the cylindrical secondary crystal is a cylindrical CsI (TL) scintillating crystal with a 2.54cm vertical diameter and a height of 1 cm.

3. A portable gamma radiation direction detector according to claim 1 or claim 2 wherein the photomultiplier tubes are GDB-23 photomultiplier tubes.

Technical Field

The invention relates to a device for sampling and recording uranium deposit gamma radiation, in particular to a portable gamma radiation directional detector.

Background

The existing gamma radiation direction finder consists of two parts, wherein one part is a gamma radiation direction detector, also called a probe; the other part is an operation table, and the operation table are connected through cables. The gamma radiation sampling is carried out in the mountain engineering such as a tunnel or a probe groove, namely, the content and the thickness of the ore body are determined on the exposed part of the ore body according to the gamma radiation intensity of the ore body. The director may also be used for gamma logging. The requirements of portability, moisture resistance, measurement precision and measurement range are met.

The basic feature of gamma radiation sampling is to eliminate interference of ambient rays and accurately measure the gamma radiation at the sampling point (see textbook "radiology survey", atomic energy press, 1990, 6 months). In order to solve the problem, a difference measurement method with a lead sleeve is widely adopted in the past, namely the lead sleeve with the lead sleeve is used for covering a detector, an opening part of the lead sleeve, which can be used for inserting and taking a lead strip, is aligned with a point, two values without the lead strip and the lead strip are measured on each measuring point, the difference does not include the influence of surrounding rays and is only related to the content of radioactive elements and the thickness of a mineral layer on the measuring point, and the secondary measurement method is high in labor intensity and low in working efficiency.

Since the last 70 s, gamma radiation orientation instruments are widely used and are disposable measurement methods. In the early days, FD-42 γ radiation orientation instruments (refer to the textbook "radiology instruments", third department of the junior college of geology, atomic energy press, 11 months 1979) were used. FD-3025A gamma radiation direction finder is now used in uranium mines, both of which are produced by general nuclear industry 263. The structure of the crystal is shown in figure 1, and the crystal is composed of a shell 1, a main crystal 2, a conical annular lead screen 3, an auxiliary crystal 4 and a photomultiplier 5. They all use waveform analysis techniques to distinguish their scintillation pulses based on the different crystals having different luminescence decay times. Although the two instruments are separated by decades, the probe of each instrument is 1.8 kilograms, and the probe is too heavy, and the root cause is to install the lead screen 3.

Disclosure of Invention

The invention aims to provide a portable gamma radiation directional detector which is used for sampling and recording gamma radiation of uranium deposit and has good directional performance.

The technical scheme for realizing the above purpose of the invention is as follows: a portable gamma radiation directional detector comprises a shell, a main crystal, a cylindrical auxiliary crystal, an annular auxiliary crystal and a photomultiplier; the main crystal cylindrical NaI (TL) inner scintillation crystal, the cylindrical auxiliary crystal is a cylindrical CsI (TL) scintillation crystal body, and the annular auxiliary crystal is a plastic annular scintillation crystal; the main crystal, the cylindrical secondary crystal and the annular secondary crystal are coaxially arranged on the end surface of the photomultiplier in the shell.

The further technical scheme of the invention is that the main crystal is a cylindrical NaI (TL) inner scintillating crystal with the vertical diameter of 2.54cm and the height of 5cm, and the cylindrical auxiliary crystal is a cylindrical CsI (TL) scintillating crystal with the vertical diameter of 2.54cm and the height of 1 cm.

The invention has the further technical scheme that the type of the photomultiplier is GDB-23 photomultiplier.

By adopting the technical scheme, the invention reduces the weight of the gamma radiation directional detector, solves the problem of heavy benzene which is not solved for a long time, and improves the directional performance of the gamma radiation directional detector. Because the lead screen is not provided, the back scattering caused by the lead screen is not provided, the volume and the weight of the probe are reduced without the lead screen, the crystals can be arranged according to the required positions without the lead screen, and the structure forms a good gamma radiation directional detector. The secondary crystal is provided for recording interfering radiation. The purpose of the lead screen in the prior art is to block the interference rays by the lead screen. The invention allows interfering rays to come in. The interference rays are recorded by the secondary crystals after coming in, and the influence of the interference rays is eliminated by the difference value of the primary crystals and the secondary crystals, so that the orientation performance of the gamma radiation orientation detector is improved. The invention has a more main significance, corrects a technical proposal that a gamma radiation directional detector which exists in the engineering industry for a long time must be provided with a lead screen, which can be referred to the two textbooks mentioned above, and the prejudice exists for half a century till now. Gamma radiation sampling has lead screens for almost a century throughout the world, including the former soviet union. In 2007, the inventor and a geophysical expert investigate the use condition of the gamma radiation direction finder on the uranium mine site, generally reflects the benzene weight of the apparatus, and the direction finding performance is poor, but no other apparatus is available, and the apparatus only needs to be compact and used, so the invention has important reference value for developing a novel apparatus.

Drawings

The invention is further described with reference to the following figures and detailed description.

FIG. 1 is a schematic diagram of a prior art gamma radiation directional detector;

fig. 2 is a schematic structural diagram of the present invention.

Detailed Description