CN110646831A

CN110646831A - Gamma ray electron spectrometer

Info

Publication number: CN110646831A
Application number: CN201911074305.6A
Authority: CN
Inventors: 易涛; 宋仔峰; 詹夏宇; 陈铭; 唐琦; 陈家斌
Original assignee: Laser Fusion Research Center China Academy of Engineering Physics
Current assignee: Laser Fusion Research Center China Academy of Engineering Physics
Priority date: 2019-11-06
Filing date: 2019-11-06
Publication date: 2020-01-03

Abstract

The invention discloses a gamma-ray electron spectrometer, which comprises a flight pipeline, a gamma-ray electron spectrometer and a control system, wherein the flight pipeline is provided with an incident port and an exit port, and a conversion body is arranged in the flight pipeline; the deflection electromagnet is positioned at an exit port of the flight pipeline and is used for receiving space electron flow formed after the conversion body is irradiated by the gamma rays; at least one electron beam current detector, which is used for receiving the space electron current after the deflection action of the deflection electromagnet and converting the space electron current into an electric signal; and the oscilloscope is connected with the electron beam current detector through a cable A and is used for receiving the electric signal. The method can realize the rapid measurement of the gamma ray energy spectrum by combining the deflection magnetic field with the signal conversion, has good accuracy and reliability, is particularly suitable for the measurement of pulse gamma rays after a synchronous machine is introduced, and further improves the stability and the safety of the operation.

Description

Gamma ray electron spectrometer

Technical Field

The invention relates to the field of gamma ray physical property detection equipment, in particular to a gamma ray electron spectrometer.

Background

Gamma rays are short wavelength ionizing radiation with photon energies typically in the range of hundreds of keV to MeV, and with significant photon energies, measuring the spectrum of gamma rays is important to understand the nature of the light source. However, because of the strong penetrating ability of gamma rays, it is difficult to separate gamma rays with different energies by common equipment or methods to quickly measure the energy spectrum of the gamma rays, and most of the existing measuring equipment has the problems of poor stability or reliability, short service life and the like.

Disclosure of Invention

In order to solve the above problems, the present invention provides a gamma-ray electron spectrometer to rapidly measure a gamma-ray energy spectrum and to improve the reliability and stability of a measuring instrument.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a gamma-ray electron spectrometer, comprising:

the flight pipeline is provided with an incident port and an emergent port, and a conversion body is arranged inside the flight pipeline;

the deflection electromagnet is positioned at an exit port of the flight pipeline and is used for receiving space electron flow formed after the conversion body is irradiated by the gamma rays;

at least one electron beam current detector, which is used for receiving the space electron current after the deflection action of the deflection electromagnet and converting the space electron current into an electric signal;

and the oscilloscope is connected with the electron beam current detector through a cable A and is used for receiving and recording the electric signal.

By adopting the structure, the incident gamma ray is irradiated on the converter to form the space electron current, the electrons excited by the gamma rays with different energies have different energies, the electrons with different energies are separated from the space by a magnetic field deflection method, the electrons are subjected to electric signal conversion by the electron current detector, and the measurement and the record are carried out by the oscilloscope, so that the intensity of the corresponding gamma spectrum can be obtained, the measurement is quick and reliable, and the damage caused by the contact of the incident gamma ray and the rear instrument equipment can be avoided by adopting the magnetic field deflection method.

Preferably, the method comprises the following steps: the device further comprises a synchronizer, and the synchronizer is respectively connected with the deflection electromagnet and the oscilloscope through a cable B and a cable C. If the synchronous machine is not available, when the pulse gamma ray is measured, the electromagnet needs to work continuously with large current, a coil can be burnt, and the system fails.

Preferably, the method comprises the following steps: and a filter disc is arranged at one end of the flying pipeline close to the incident port. By adopting the scheme, the incident gamma rays can be filtered or attenuated and the like through the filter disc, and the gamma rays with moderate intensity are ensured to be irradiated onto the conversion body.

Preferably, the method comprises the following steps: and one end of the flight pipeline, which is close to the emergent port, is provided with a limiting hole. By adopting the scheme, electrons in a specific direction can be limited to enter the deflection electromagnet through the limiting hole, and the requirement of higher measurement precision is met.

Preferably, the method comprises the following steps: the deflection angle of the deflection electromagnet is 90 degrees. By adopting the scheme, the electron beam detector and the gamma ray are arranged in the 90-degree angle in the incident direction, so that the gamma ray can be effectively prevented from being directly applied to the electron beam detector to damage the electron beam detector, the running safety of equipment can be improved, and the service life of the equipment can be prolonged.

Compared with the prior art, the invention has the beneficial effects that:

the gamma-ray electron spectrometer provided by the invention can realize the rapid measurement of the gamma-ray energy spectrum by combining the deflection magnetic field with the signal conversion, has good accuracy and reliability, is more suitable for the measurement of pulse gamma-rays particularly after a synchronous machine is introduced, and further improves the stability and the safety of the operation together.

Drawings

FIG. 1 is a schematic structural view of the present invention;

fig. 2 is a working principle diagram of the synchronous machine.

Detailed Description

The present invention will be further described with reference to the following examples and the accompanying drawings.

Referring to fig. 1 and 2, a gamma-ray electron spectrometer mainly includes a flight tube 1, a deflection electromagnet 3, at least one electron beam detector 4, and an oscilloscope 5, wherein the flight tube 1 is in a hollow straight tube shape, the flight tube 1 is made of a metal material, two ends of the flight tube 1 are open and respectively form an entrance port 10 and an exit port 11, a converter 2 is arranged in the flight tube 1, the converter 2 is in a crystal or metal structure, when the converter 2 is irradiated by gamma rays, space electron current can be formed by the compton effect and the electron pair effect, and the electron energies formed by exciting the converter 2 by different gamma rays are different.

The deflection electromagnet 3 has a certain deflection angle, is positioned at an exit port 11 of the flight pipeline 1 and is provided with a channel through which the work electron flow passes, and the electron beam detector 4 mainly comprises optical glass and a fast response multiplier tube, wherein the optical glass is over against the tail end of the channel of the deflection electromagnet 3, so that after the space electron flow formed by the converter 2 enters the channel of the deflection electromagnet 3, electrons with different energies are separated from the space under the action of a deflection magnetic field, and finally bombarded on the optical glass to deposit energy luminescence which is collected and recorded by the fast response multiplier tube.

In the measuring process, in order to ensure the accuracy of the measuring result, the channel of the deflection electromagnet 3 is tightly connected with the exit port 11, and the electron flight path between the conversion body 2 and the optical glass is ensured to be in a vacuum state, so that the space electron current is prevented from being influenced by the environmental gas flow, and meanwhile, a plurality of electron beam detectors 4 are arrayed at the tail end of the channel of the deflection electromagnet 3, so that the electron loss is avoided.

The electron beam detector 4 is connected with the oscilloscope 5 through a cable A50, so that the photomultiplier can convert collected electrons into electric signals and transmit the electric signals to the oscilloscope 7, and the energy spectrum of incident gamma rays can be rapidly and intuitively obtained through amplification and shaping of the oscilloscope 7 and the like.

In the measurement process, the deflection electromagnet 3 needs large current and runs for a long time, the heating problem is obvious, the risk of coil burning and system failure exists, particularly when the device is used for measuring pulse gamma rays, the risk is higher, and the service life of instrument and equipment is greatly shortened, so that a synchronizer 6 is further introduced for measuring the pulse gamma rays in the application, as shown in the figure, the synchronizer 6 is respectively connected with the deflection electromagnet 3 and an oscilloscope 5 through a cable B60 and a cable C61, the working condition control of the deflection electromagnet 3 is realized through a synchronization mechanism, and the cable B60, the cable C61 and the cable A50 are all coaxial cables.

The synchronizer 6 is the same as most of the existing synchronous control equipment, mainly comprises a beam splitting module and a time delay module, and is provided with a trigger signal input port and a synchronous signal output port, an external trigger signal enters the synchronizer through the trigger signal input port, a plurality of beams of the same trigger signals formed by the beam splitting module respectively enter a plurality of time delay modules, and the synchronous signals are respectively output after delaying preset time according to time delay set values of different time delay modules.

In this embodiment, when measuring the pulsed gamma ray, the trigger signal may be a manual control switch, or may be a control device related to the gamma generator, that is, before the gamma generator is started, the trigger signal may be transmitted to the gamma generator through a trigger signal input port, the synchronizer 6 starts the deflection electromagnet 3 before the gamma is incident according to the delay time, that is, the deflection electromagnet 3 is charged to form a strong magnetic field, after the electron beam is deflected and enters the photomultiplier to be recorded, and is converted into an electrical signal to be recorded by the oscilloscope 5, and then no electrical signal enters the oscilloscope 5, the synchronizer 6 may send an instruction to the deflection electromagnet 3 again to cut off the current of the deflection electromagnet 3, so as to prevent the deflection electromagnet 3 from being damaged due to long-time passing large current overheating, and after the corresponding time interval, the synchronizer 6 starts the deflection electromagnet 3 again according to the trigger signal, the pulse frequency of the pulse gamma is adapted to the reciprocating motion, and meanwhile, the deflection electromagnet 3 does not need to be continuously electrified for a long time through the matching of the synchronizer 6 and the deflection electromagnet 3.

As shown in fig. 1, in the present embodiment, a filter 7 and a limiting hole 8 are respectively disposed on two sides of a conversion body 2 in a flight duct 1, wherein the filter 7 is located at one end of an incident port 10, and the limiting hole 8 is located at one end of an exit port 11, the filter 7 is mainly used for filtering, adjusting or attenuating incident gamma rays, and so on, so as to ensure that the intensity of the gamma rays irradiated onto the conversion body 2 is moderate, and of course, the filter 7 can be selectively replaced according to needs, and the limiting hole 8 is formed by a hole plate structure, and is mainly used for blocking off electrons having a deviated direction, and limiting the electrons having a specific direction from entering a passage of a deflection electromagnet 3 through the limiting hole 8.

In addition, in order to avoid the direct irradiation of the electron beam detector 4 by the gamma ray, which causes equipment damage and the like, the deflection angle of the deflection electromagnet 3 is preferably 90 degrees, so that the arrangement direction of the electron beam detector 4 and the incidence direction of the gamma ray are distributed in a 90-degree included angle, the incidence direction of the gamma ray is completely avoided, and the safety and reliability of the measuring equipment are ensured.

Referring to fig. 1 and 2, the gamma-ray electron spectrometer operates as follows: aiming at the measurement of the pulse gamma, before the gamma is incident, a working instruction is sent to the deflection electromagnet 3 in advance through the synchronizer 6, so that the deflection electromagnet 3 is charged to form a strong deflection magnetic field, then the pulse gamma ray is incident, after being adjusted by the filter 7, the gamma ray with moderate intensity is irradiated on the converter 2 to form space electron current, electrons in a specific direction enter the deflection electromagnet 3 after passing through the limiting hole 8, under the action of the deflection magnetic field, electrons with different energies are deflected and enter different electron beam detectors 4, and are converted into electric signals to be transmitted to the oscilloscope 5, and the energy spectrum of the measured gamma ray can be obtained through the shaping and amplification of the oscilloscope.

Finally, it should be noted that the above-mentioned description is only a preferred embodiment of the present invention, and those skilled in the art can make various similar representations without departing from the spirit and scope of the present invention.

Claims

1. A gamma-ray electron spectrometer, comprising:

a flight duct (1) having an entrance port (10) and an exit port (11), and having a conversion body (2) disposed therein;

the deflection electromagnet (3) is positioned at an exit port (11) of the flight pipeline (1) and is used for receiving space electron current formed after the gamma ray irradiates the conversion body (2);

at least one electron beam current detector (4) for receiving the space electron current deflected by the deflection electromagnet (3) and converting the space electron current into an electric signal;

and the oscilloscope (5) is connected with the electron beam current detector (4) through a cable A (50) and is used for receiving and recording the electric signals.

2. The gamma-ray electron spectrometer of claim 1, wherein: the device is characterized by further comprising a synchronizer (6), wherein the synchronizer (6) is respectively connected with the deflection electromagnet (3) and the oscilloscope (5) through a cable B (60) and a cable C (61).

3. The gamma-ray electron spectrometer of claim 1, wherein: and a filter disc (7) is arranged at one end, close to the entrance port (10), in the flying pipeline (1).

4. The gamma-ray electron spectrometer of claim 1, wherein: and a limiting hole (8) is arranged at one end, close to the exit port (11), in the flight pipeline (1).

5. The gamma-ray electron spectrometer of claim 1, wherein: the deflection angle of the deflection electromagnet (3) is 90 degrees.