CN-116794709-B - Online alpha combination detector

CN116794709BCN 116794709 BCN116794709 BCN 116794709BCN-116794709-B

Abstract

The online alpha combined detector integrates a ZnS (Ag) detector and a PIPS (ion implantation type passivation silicon) detector, the ZnS (Ag) detector and the PIPS detector are insensitive to environmental gamma rays, so that the online alpha combined detector has lower background and detection lower limit without an additional shielding device, the ZnS (Ag) detector is insensitive to beta rays, a threshold value is reasonably set, the interference of the beta rays on the ZnS (Ag) is negligible, the PIPS is concentrated in a low-energy area, the interference of the beta rays can be eliminated through an energy spectrum analysis algorithm or by improving the lower limit of the energy spectrum threshold value, the influence of the beta rays and the gamma rays on the combined detector to measure alpha particles is greatly reduced, the detection precision of the alpha particles is improved, the ZnS (Ag) detector is coupled with a plurality of PMTs, the detection efficiency is further ensured, the detection window structure benefits from a unique design, the window material aluminum foil, the titanium foil and the gold foil are flexibly adapted, and the detector is strong acid resistant to strong alkali and corrosion, and has wider use scenes.

Inventors

YANG ZHIJIE
Fang Yingtong
HOU LIUDONG
LI GUIWEN
LIU MEILING
LIANG JUNCHENG
ZHAO YAPING
LIU HAORAN
FAN ZIHAO
ZHANG ZHAOQING

Assignees

中国计量科学研究院
中国核电工程设计有限公司

Dates

Publication Date: 20260512
Application Date: 20230417

Claims (7)

1. The online alpha combined detector is characterized by comprising a detector head threaded part light shielding film and a bracket, a PIPS fixed support (2), a ZnS (Ag) detector (3), a PMT collimation plate (4), a PIPS detector (5), a PIPS detector fixed ring (6), a PIPS front packaging tube (7), a PMT (8), a PMT fixing part (9), an M3 copper column and sleeve (10), a spring (11), an electronic circuit board, a main board connecting copper column (13), a hexagonal copper column (14), a combined detector rear cover (15), a combined detector rear cover outlet plate (16), a combined detector sleeve (17) and a relative position fixing part (18); The detector head screw light-shielding film and the bracket of the combined detector comprise a head screw (101), a light-shielding film bracket (102) and a bottom screw (103); the head screw (101) of the combined detector is positioned on the outermost layer of the front end of the combined detector; The outer layer of the light-shielding film support (102) is provided with threads, and the light-shielding film support and the head threaded piece (101) of the combined detector are in threaded fit, so that the light-shielding film support and the head threaded piece can be tightly attached; the light shielding film support (102) is positioned between the head screw (101) and the bottom screw (103); The PIPS fixed support (2) may enable a PIPS detector (5) to be fixed in a combined detector sleeve (17); The combined detector sleeve (17) is made of metal, the combined detector is in a concentric sleeve shape, and the combined detector components are assembled in the combined detector sleeve (17); The front end of the combined detector sleeve (17) can be fixed with the threaded part (101) of the head part of the combined detector, and the rear end of the combined detector sleeve (17) can be matched with the rear cover of the combined detector, so that the detector is fixed in the sleeve of the combined detector; The ZnS (Ag) detector (3) is in a circular ring shape, and a PIPS detector (5) is hollowed and embedded in the center of the ZnS (Ag) circular ring; the PIPS detector (5) is fixed with the ZnS (Ag) detector (3) through a PIPS detector fixing ring (6); the front end of the combined detector is a ZnS (Ag) detector (3) coupled with PMTs (8), and 2-6 PMTs (8) are distributed around the PIPS detector (5) at equal intervals; the PIPS front packaging tube (7) is positioned at the center of the front end of the PIPS detector (5); The PMT collimation plate (4) is positioned in front of the PMT (8); the PMT fixing member (9) is located behind the PMT (8) and fixes the PMT (8).
2. The combination detector of claim 1, The tube seat of each PMT (8) is fixed on a structural member through a screw, an M3 copper column and a sleeve (10) are arranged on the structural member, a spring (11) is sleeved on the copper column, the diameter of the spring (11) is larger than that of the round copper column, the round copper column can be extruded into the sleeve, the spring (11) always has elastic supporting effect on the PMT (8), and therefore the PMT (8) is always tightly attached to the ZnS (Ag) detector (3); The relative position fixing piece (18) is positioned at the front part of the combined detector, one side of the relative position fixing piece is contacted with the ZnS (Ag) detector (3), and the other side of the relative position fixing piece is contacted with the PIPS detector (5), so that the relative position of the two detectors is fixed.
3. The combination detector of claim 1, The electronic circuit board of the combined detector comprises a PMT analog board (1201), a power supply board (1202), a digital board (1204) and a PIPS processing board (1203), wherein holes are formed in the electronic circuit board; the PIPS detector (5) is connected with the PIPS processing board (1203) through a wire, the PIPS detector (5) outputs a positive pulse signal to the PIPS processing board (1203) for energy spectrum analysis, and the obtained energy spectrum data is transmitted to the digital board (1204) for further processing; And the anode of the PMT (8) outputs a negative pulse signal to the PMT analog board (1201), and outputs a TTL pulse signal to the digital board (1204) for pulse counting after the PMT analog board (1201) performs reverse amplification, threshold comparison and pulse shaping.
4. The combination detector as claimed in claim 3, wherein, The digital board (1204) is provided with an interface for communicating with the outside and exchanging data; the electronic circuit board is fixed and connected with the rear cover (15) of the combined detector at intervals through M3 copper columns; One end of the M3 copper column is connected with a tube seat fixing piece of the PMT (8), and the other end of the M3 copper column penetrates through a PMT simulation board (1201) to be connected with the motherboard connecting copper column (13).
5. The combination detector of claim 1, The combined detector sleeve (17) is made of metal, the combined detector is in a concentric sleeve shape, and the combined detector components are assembled in the combined detector sleeve (17); The front end of the combined detector sleeve (17) can be fixed with the threaded part (101) of the head of the combined detector, and the rear end of the combined detector sleeve (17) can be matched with the rear cover (15) of the combined detector, so that the detector is fixed in the sleeve of the combined detector; the rear cover (15) of the combined detector is provided with 1 communication port which can carry out information transmission with the outside; the rear cover (15) of the combined detector is provided with 1 power interface, and the outside can input power to supply power to the detector.
6. The combination detector as claimed in claim 3, wherein, The bottom surface of the relative position fixing piece (18) is provided with a reflective coating; the digital board (1204) communicates with the outside through an RS485 port; The light-shielding film bracket can be independently screwed out and replaced on the premise of not disassembling the combined detector; the metal material of the combined detector tube sleeve is 316L stainless steel.
7. The combination detector of claim 1, The light-shielding film support (102) of the combined detector can be replaced, and the light-shielding film is made of aluminum, titanium or gold.

Description

Online alpha combination detector Technical Field The invention relates to the technical field of alpha detectors, in particular to an online alpha combination detector. Background The french physicist beckle first found a natural radioactive phenomenon in uranium salts, and since then people began to study and utilize radionuclides, wherein the radionuclides of alpha decay account for a large proportion, and have been widely used in the fields of medicine, aerospace, military, energy and the like. However, the nuclides inevitably have the risk of radioactive leakage during research, production, storage, transportation and application; Although research shows that alpha particles have weak penetrating power, can lose energy rapidly when running in a medium and can be absorbed in air with the thickness of a few centimeters, alpha particles have strong ionization capability, and once entering a human body, the alpha particles can directly destroy visceral tissue cells to cause tissue damage; The method has the advantages that the method is simple in structure, convenient to use, and easy to operate, and can be used for detecting the positions where the pollution and leakage of the alpha radioactive nuclide possibly exist at regular intervals to ensure the body health of related personnel aiming at the safety risk of the alpha radioactive nuclide in the storage, transportation or use process, or judging the pollution degree of the areas where the alpha radioactive nuclide exists through detection to take corresponding emergency measures, under the scenes, the detection of the alpha radioactive nuclide is extremely important, and the alpha detector can also search for certain radioactive mineral deposits, underground water and radioactive exploration for solving other geological problems by measuring the quantity of alpha particles generated by radon and radon, so that the method has wide application prospect; The conventional alpha particle radiation detector mainly comprises a gas detector, a semiconductor detector and a scintillator detector, wherein the gas detector is sensitive to beta rays and gamma rays, the background is high, an additional shielding is required to be added to enable the detector to have a lower detection lower limit, in the semiconductor detector, the conventional silicon surface barrier (SS B) detector and the conventional Diffusion Junction (DJ) detector are large in leakage current, the dead layer thickness is thick, the field detection efficiency is generally lower than that of the scintillator detector, the scintillator detector is poor in light transmittance, but has higher luminous efficiency and higher detection efficiency, but the energy resolution is not as high as that of the semiconductor detector, and most of the detector has higher sensitivity to beta rays and gamma rays besides ZnS (Ag) detectors, so that the measurement effect of alpha particles can be influenced. The actual detection environment of the detector is often accompanied with strong corrosiveness of strong acid and strong alkali, but the existing disclosed alpha detector cannot be considered with low detection lower limit, high detection efficiency, energy discrimination and severe environment resistance; Accordingly, those skilled in the art have focused their efforts on developing an online α -combination detector that addresses the shortcomings of the prior art. Disclosure of Invention In view of the above-mentioned drawbacks of the prior art, the present invention aims to solve the technical problems that in the prior art, a scintillator detector has poor energy spectrum resolution, higher sensitivity to beta and gamma rays, higher background, and a detector detects a severe environment, while the existing alpha detector cannot consider low detection lower limit, high detection efficiency, energy discrimination performance and severe environment resistance. In order to achieve the above purpose, the invention provides an online alpha combined detector, which comprises a detector head screw thread piece light shielding film and a bracket, a PIPS fixed support piece, a ZnS (Ag) detector, a PMT collimation plate, a PIPS detector fixed ring, a PIPS front packaging tube, a PMT fixed piece, an M3 copper column and sleeve, a spring, an electronic circuit board, a main board connecting copper column, a hexagonal copper column, a combined detector back cover wire plate, a combined detector sleeve and a relative position fixed piece; The detector head screw thread piece light-shielding film and the bracket of the combined detector comprise a head screw thread piece, a light-shielding film bracket and a bottom screw thread piece; the head threaded piece of the combined detector is positioned on the outermost layer of the front end of the combined detector; the outer layer of the light-shielding film support is provided with threads, and the light-shielding film support and the head threaded piece of the combined de