CN112782747B

CN112782747B - Multi-blade Faraday cylinder, multi-blade Faraday cylinder measuring system and application thereof

Info

Publication number: CN112782747B
Application number: CN202110010455.1A
Authority: CN
Inventors: 肖舒颜; 郭刚; 张艳文; 覃英参; 殷倩; 杨新宇
Original assignee: China Institute of Atomic of Energy
Current assignee: China Institute of Atomic of Energy
Priority date: 2021-01-05
Filing date: 2021-01-05
Publication date: 2022-04-08
Anticipated expiration: 2041-01-05
Also published as: CN112782747A

Abstract

The disclosure provides a multi-blade Faraday cage, a multi-blade Faraday cage measuring system and applications thereof. The multi-blade Faraday cage is suitable for atmospheric environment measurement and comprises a plurality of conductors and insulators which are alternately arranged, wherein the conductors and the insulators are tightly connected through insulated fasteners; the conductor is used for depositing electric charges carried by detected particles in detected beam current, and the insulator is used for preventing secondary electrons generated on the conductor from diffusing between adjacent conductors. The multi-blade Faraday cylinder has a simple structure and small occupied space, and the compact structure can discharge air in the device, so that the background noise of the multi-blade Faraday cylinder measured in the atmospheric environment is greatly reduced, and the test accuracy and precision are improved. Based on the multi-blade Faraday cylinder, the multi-blade Faraday cylinder measuring system can realize automatic measurement of proton beam current in different energy ranges in the atmospheric environment, ensures the safety of the measuring process, and is convenient and quick to operate.

Description

Multi-blade Faraday cylinder, multi-blade Faraday cylinder measuring system and application thereof

Technical Field

The disclosure belongs to the technical field of cyclotrons, and particularly relates to a multi-blade Faraday cylinder, a multi-blade Faraday cylinder measuring system and application thereof.

Background

The proton can be used for irradiating a microelectronic device chip and evaluating the single event effect resistance of the device in a space environment, secondary particles generated by the proton through nuclear reaction cause a single event effect, and the nuclear reaction result of the proton and a device material changes along with energy, so that in a proton single event effect test, accurate measurement of the proton energy of an incident device is very important.

The multi-blade Faraday cup (MLFC) is an energy measuring tool commonly used for quickly confirming the beam energy of a high-energy proton accelerator at present, has a very simple structure, is almost free of radiation damage compared with a gold silicon surface barrier detector commonly used for measuring the low-energy proton energy, and is widely applied to proton single event effect tests and nuclear medicine treatment at present abroad. The proton single event effect test exceeding 20MeV can be carried out in the atmospheric environment, and the accurate measurement of the proton energy of an incidence device requires that a multi-blade Faraday cylinder and the incidence device are positioned in the same plane in the atmosphere, but the currently developed multi-blade Faraday cylinder is only suitable for vacuum environment measurement and cannot carry out rapid measurement on the proton energy in the atmospheric environment.

Disclosure of Invention

The present disclosure provides, in one aspect, a multi-leaf faraday cage suitable for atmospheric environment measurement, comprising a plurality of alternately arranged conductors and insulators, the conductors and insulators being tightly connected by insulated fasteners; the conductor is used for depositing electric charges carried by detected particles in detected beam current, and the insulator is used for preventing secondary electrons generated on the conductor from diffusing between adjacent conductors.

Optionally, when the energy of the detected particle is larger, or when the capability of preventing the detected particle is required to be stronger, the conductor is made of a material with a larger atomic mass number; when the energy or angle of the detected particles in the conductor is larger, or when the material of the conductor is more activated, the conductor is made of the material with the smaller atomic mass number.

Optionally, the conductor is made of a material including copper, aluminum, iron, or cadmium.

Optionally, the insulator is made of an insulating material with ductility and high temperature resistance.

Optionally, the insulating material used for the insulator is polyimide.

Optionally, the insulator is a Kapton film made of polyimide.

Another aspect of the present disclosure provides a multi-leaf faraday cup measurement system, adapted for atmospheric environment measurement, comprising: a multi-leaf faraday cage comprising a plurality of alternating conductors and insulators, the conductors and insulators being closely connected by insulated fasteners; the conductor is used for depositing electric charges carried by detected particles in detected beam current, and the insulator is used for preventing secondary electrons generated on the conductor from diffusing between adjacent conductors; the signal acquisition device is used for acquiring the measured beam current signals deposited on the conductor, scanning the measured beam current signals and outputting scanning signals; the signal measuring device is used for receiving the scanning signal output by the signal acquisition device, acquiring a corresponding current spectrum according to the scanning signal and then outputting a test value according to the maximum peak value of current in the current spectrum; and the controller is used for controlling the signal acquisition device and the signal measurement device and reading the measured beam current signal, the scanning signal and the test value.

Optionally, the signal acquisition device comprises: the signal switching unit is electrically connected with an output channel of a conductor in the multi-blade Faraday cage and is connected with the output channel of the conductor by controlling the signal switching unit to realize the acquisition of the measured beam current signal deposited on the conductor; and the signal scanning unit is used for receiving the measured beam flow signal, scanning the measured beam flow signal and outputting a scanning signal.

Optionally, the signal switching unit includes two layers of switches, where an input terminal of each switch in the first layer of switches controls output channels of the two conductors, an input terminal of one switch in the second layer of switches controls output terminals of two switches in the first layer of switches, and output terminals of a plurality of switches in the second layer of switches are connected to channels of the signal scanning unit in a one-to-one correspondence manner.

Optionally, the signal measuring device includes one or more electrometers, and the electrometers are configured to sequentially receive the scanning signal, obtain a corresponding current spectrum according to the scanning signal, obtain a current maximum peak in the current spectrum within a preset measurement time, and obtain a measured value of the energy of the measured beam current according to the current maximum peak.

Optionally, the controller comprises: the signal control unit is used for controlling the signal switching unit to switch the first layer of switch and the second layer of switch and transmitting the detected beam current signal on the conductor to the signal scanning unit; and controlling the signal scanning unit to scan the detected beam current signal; and controlling the signal measuring device to measure the scanning signal output by the signal scanning unit and output a test value; and the data reading unit is used for reading the beam stream signal to be tested, the scanning signal and the test value.

Optionally, the controller further comprises a display unit for displaying the measured beam current signal, the scanning signal and the test value.

Optionally, the controller further comprises a storage unit for storing the measured beam current signal, the scan signal and the test value.

Another aspect of the disclosure provides a method for measuring different proton energies using a multi-leaf faraday cup measurement system, comprising: when the energy of the measured beam current is completely deposited in the multi-blade Faraday cylinder, outputting a first signal to control the two layers of the change-over switches to be switched to a passage corresponding to the first conductor, collecting and scanning the measured beam current signal on the first conductor, and outputting a first scanning signal; repeatedly executing the operations until the acquisition and scanning of the measured beam current signals on all the conductors are completed; and outputting a second signal to control the signal measuring device to sequentially receive scanning signals output by scanning the measured beam current signals on all conductors, acquiring a corresponding current spectrum, and outputting a test value according to the maximum current peak value in the current spectrum.

The beneficial effect of this disclosure does:

(1) the multi-blade Faraday cylinder has the advantages of simple structure and small occupied space, and the compact structure can discharge air in the device, greatly reduce the background noise of the multi-blade Faraday cylinder in measurement in the atmospheric environment, and improve the test accuracy and precision.

(2) The multi-blade Faraday cylinder measuring system is simple in structure, small in occupied space, capable of achieving automatic measurement of proton beam current in different energy ranges in the atmospheric environment, capable of guaranteeing safety of the measuring process, and convenient and fast to operate.

Drawings

FIG. 1 schematically illustrates a multi-leaf Faraday cage structure in an embodiment of the disclosure;

figure 2 schematically illustrates a multi-leaf faraday cage operational schematic in an embodiment of the present disclosure;

FIG. 3 schematically illustrates a block diagram of a multi-leaf Faraday cage measurement system in accordance with embodiments of the disclosure;

FIG. 4A schematically illustrates a block diagram of a controller in a multi-leaf Faraday cup measurement system, according to an embodiment of the disclosure;

FIG. 4B is a block diagram of a controller in a multi-leaf Faraday cup measurement system, according to another embodiment of the disclosure;

FIG. 4C is a block diagram of a controller in a multi-leaf Faraday cup measurement system, according to another embodiment of the disclosure;

figure 5 schematically illustrates a flow chart of a method for measuring different proton energies using a multi-leaf faraday cage measurement system in an embodiment of the disclosure.

Figure 6 shows the results of measurements of different proton energies using a multi-leaf faraday cup measurement system in an embodiment of the disclosure.

Description of reference numerals:

100-a multi-leaf faraday cage; 110-an insulator; 120-a conductor; 130-fasteners, 131-screws; 132-a nut; 210-an ammeter; 300-a multi-leaf faraday cage measurement system; 310-a signal acquisition device; 311-a signal switching unit; 312-a signal scanning unit; 320-signal measuring means; 330-a controller; 331-a signal control unit; 332-a data reading unit; 333-display unit; 334-memory cell.

Detailed Description

For a better understanding of the objects, aspects and advantages of the present disclosure, reference is made to the following detailed description taken in conjunction with the accompanying drawings.

The metal conductor sheet in the existing multi-blade Faraday cage is easily influenced by free ions and charged aerosol in the atmospheric environment, so that the detection background of the multi-blade Faraday cage is greatly improved, electrons generated by air ionization are attracted by high potential caused by proton collection on the metal conductor sheet and move to the metal sheet to offset a part of measurement signals, and the measurement of the multi-blade Faraday cage is further influenced. Based on this, the present disclosure provides a multi-blade faraday cup and a multi-blade faraday cup measurement system to solve the above technical problems.

Fig. 1 schematically illustrates a multi-leaf faraday cage configuration in an embodiment of the disclosure.

As shown in fig. 1, the multi-leaf faraday cup 100 is suitable for atmospheric environment measurements. The multi-leaf faraday cage 100 includes a plurality of conductors 120 and insulators 110 alternately arranged, and the conductors 120 and insulators 110 are closely coupled by insulated fasteners 130 to exclude air from the interior of the multi-leaf faraday cage 100. The conductor 120 is used for depositing charges carried by particles (such as protons) to be detected in the detected beam current, and the insulator 110 is used for blocking secondary electrons generated on the conductor 120 from diffusing between adjacent conductors.

Compared with the prior art, the multi-blade Faraday cylinder has the advantages that the structure is simple, the occupied space is small, the compact structure can discharge air in the device, the background noise of the multi-blade Faraday cylinder in measurement in the atmospheric environment is greatly reduced, and the test accuracy and precision are improved.

Figure 2 schematically illustrates a diagram of the operation of a multi-leaf faraday cage in an embodiment of the present disclosure.

As shown in fig. 2, multi-leaf faraday cup 100 is comprised of a plurality of alternating conductors and insulators, each conductor 110 connected to a current meter 210. When a particle to be measured (for example, a proton, hereinafter, the particle to be measured is described as a proton), enters the multi-leaf faraday cup 100, energy is lost due to ionization and nuclear reaction and stays in the multi-leaf faraday cup 100, and the proton has a fixed range in a substance due to the bragg peak, so that most of the proton stays on the conductor 120 corresponding to the end of the range, so that the potential of the conductor 120 is increased, and electrons are pulled onto the conductor from a low potential. A current spectrum can be obtained by measuring the current on all conductors, and the proton energy can be detected in a short time through the thickness of the conductor sheet where the maximum peak value of the current is located.

In the disclosed embodiment, insulated fasteners 130 are used to compress insulator 110 and conductor 120, allowing air inside multi-lobed faraday cup 100 to vent, thereby reducing or even eliminating the effect of free ions and charged aerosols in the air on the detection background, resulting in a substantial reduction in the background noise. The insulating fastener 130 may be, for example, a fastening structure composed of a screw 131 and a nut 132, or may be fixed by an elastic member, such as an elastic sealing ring, which is not limited herein, as long as it can insulate, seal, and compress all of the conductors 120 and the insulators 110 so that air inside the multi-leaf faraday cage 100 can be removed.

In order to reduce the influence of the atmospheric environment according to the embodiment of the present disclosure, the insulator 110 needs to be compressed with the conductor 120 so as to remove air, and the material of the insulator 110 needs to have good ductility. In addition, the energy during the beam process is high, the insulator 110 needs to prevent secondary electrons generated on the conductor 120 from diffusing between adjacent conductors, and the material used for the insulator 110 needs to have good high temperature resistance. Based on this, in the material selection of the insulator 110, an insulating material having good ductility and high temperature resistance can be selected. In the embodiment of the present disclosure, the insulating material used for the insulator 110 may be, for example, a polyimide-based material, and in the embodiment of the present disclosure, the Kapton film made of a polyimide material may be used as the insulating material between the conductors 120 for the insulator 110.

According to an embodiment of the present disclosure, the selection of the material of the conductor 120 in the multi-leaf faraday cup 100 requires a sufficient consideration of the energy range of the particle (e.g., proton) being measured, the ability of the material of the conductor 120 to block the particle being measured, the energy divergence and angular divergence of the particle being measured in the material of the conductor 120, and the activation of the material of the conductor 120.

According to the embodiment of the present disclosure, the conductor 120 is made of a material with a larger atomic mass number when the energy of the detected particle is larger, or when the capability of blocking the detected particle is required to be stronger. For example, when the energy of the detected particle is 100MeV, the conductor 120 may be made of a material with a large atomic mass number (e.g., copper) as the material of the conductor 120. When the energy of the detected particle is 45MeV, the conductor 120 may be made of a material with a small mass number (e.g., aluminum) as the material for the conductor 120. The atomic mass number is the sum of the number of protons (Z) and the number of neutrons (N) in a neutral atom, i.e., the atomic mass number (a) ═ the number of protons (Z) + the number of neutrons (N).

According to the embodiment of the present disclosure, the conductor 120 is made of a material with a smaller atomic mass number when the energy or angle of the detected particle in the conductor 120 is larger, or when the material of the conductor 120 is activated (i.e., induced to be radioactive) to a larger extent.

Specifically, the energy loss of each incident particle fluctuates around the average value, and the statistical distribution of such energy losses is called energy straggling. The energy discrimination for energetic particles in the material of the conductor 120 can be represented by the mean square error of the energy loss distribution, which satisfies the formula:

wherein σ_eThe mean square error of the energy loss distribution is shown, e is the unit charge of static electricity, Z is the atomic number of the incident charged particles, Z is the atomic number of the target substance, N is the atomic density of the target substance, and Δ x is the thickness of the target substance.

The degree of angular straggling can be expressed by the mean square value of the angular deflection, or by the mean square parameter σ of the gaussian distribution according to the gaussian distribution theory of the angular deflection, and there are many calculation formulas for the mean square value, among which the formula of Highland is relatively simple and widely used, and the formula is in the form of:

where θ is the mean square error of the angular deflection, z is the charge number of the incident particle, E is the kinetic energy of the incident particle, L is the mass thickness of the scatterer_RRad is the radial length of the scatterer.

The target substance described in the above formula (1) and the scatterer described in the formula (2) may be understood as the material used for the conductor 120 in the present disclosure, and the incident charged particle in the formula (1) and the incident particle in the formula (2) may be understood as the measured particle in the present disclosure. According to the above calculation formulas of energy straggling and angular straggling, the range deviation caused by the energy straggling and angular straggling of the detected particles in the material of the conductor 120 can be calculated, and then the proper conductor material can be selected according to the conditions of energy straggling and angular straggling.

According to the embodiment of the disclosure, the energy measurement range of the multi-blade Faraday cup 100 is 0MeV to 100 MeV. Further, in the disclosed embodiments, the multi-leaf Faraday cup 100 can be measured with an accuracy of at least 90% over an energy measurement range of 45MeV to 100 MeV.

In the embodiment of the disclosure, when the material of the conductor 120 is selected, the range deviation caused by the energy divergence and the angle divergence of the measured particles in the material of the conductor 120 is required to meet the measurement accuracy requirement of the multi-blade faraday cage 120. On the premise that the range deviation caused by the energy divergence and the angle divergence meets the measurement accuracy requirement, the material of the conductor 120 may be selected according to actual requirements (for example, considering the manufacturing cost, the material processing accuracy requirement, the material processing difficulty, the device structure requirement, the safety, and the like). For example, if miniaturization of a multi-leaf faraday cage is required, a material with a large atomic mass number (e.g., copper may be selected as the material of conductor 120) satisfying the conditions of energy divergence and angular divergence may be used, and a material with a small atomic mass number (e.g., aluminum may be selected as the material of conductor 120) may be selected if strict control over the activation of the material of conductor 120 is required.

According to an embodiment of the present disclosure, the material of the conductor 120 may include copper, aluminum, iron, or cadmium, or other suitable metal materials, which are selected according to actual requirements (for example, considering manufacturing cost, material processing precision requirement, material processing difficulty, and the like).

After the material of the conductor 120 is confirmed, the number of layers and the thickness of the conductor 120 in the multi-leaf faraday cup 100 are calculated by simulation in accordance with the measurement range and the measurement accuracy. In the embodiment of the disclosure, the copper sheet can be selected as the material of the conductor 120, and is selected because the copper sheet meets the requirement of measurement accuracy (for example, the measurement accuracy is greater than or equal to 90% in the energy measurement range of 45-100 MeV), and the material has a large atomic mass number, so that the thickness of the multi-leaf faraday cage 100 can be effectively reduced, and the multi-leaf faraday cage can be miniaturized. The material of the insulator 110 may be, for example, Kapton film made of polyimide, which has good ductility, high temperature resistance and insulation, and can block the diffusion of secondary electrons generated on the conductor 120 between adjacent conductors.

The number of layers and the thickness of the conductor 120 are calculated by simulation, firstly, the range of the measured particles (such as protons) in the conductor (such as copper sheet) 120 and the insulator (such as Kapton film) 110 is calculated by using the SRIM program, and then the thickness of the conductor (such as copper sheet) 120 and the insulator (such as Kapton film) 110 is selected according to the calculation result of the range.

In the embodiment of the disclosure, the number of layers of the conductor 120 is not more than 36, but the number of layers of the conductor 120 is not limited to the above number of layers, the total number of layers of the conductor 120 can be increased according to the measurement requirement, and the increase of the number of layers of the conductor 120 is beneficial to improving the measurement accuracy of the multi-blade faraday cage 100. If the accuracy of multi-leaf faraday cup 100 is to be increased, the thickness of each layer of conductor 120 can be reduced, the total number of layers increased, and more signals measured using a more advanced signal acquisition system. According to an embodiment of the present disclosure, each layer of the conductor 120 is less than 500 μm thick. The thickness of each layer of the conductor 120 is specifically designed and selected according to the measurement requirements. In the disclosed embodiment, insulator 110 is less than 50 μm thick per layer. The thickness of each layer of the insulator 110 has a small influence on the measurement result, and can be designed and selected according to the actual situation for the insulator 110.

In the embodiment of the disclosure, the compact structure of the multi-blade Faraday cup can discharge air in the device, thereby greatly reducing the background noise of the multi-blade Faraday cup measured in the atmospheric environment and improving the test accuracy and precision.

Multi-leaf Faraday can measure generally 10⁶cm^-2·s^-1The specific lower measurement limit of the proton beam current depends on the minimum measurement range of the measurement module (for example, an electrometer is used as the measurement module) and the environmental background noise, and the maximum measurement range of the electrometer or the high environmental background noise will increase the lower measurement limit, and vice versa. The upper limit of measurement is different depending on the heat dissipation condition of the metal conductor layer. The fluence rate required by proton single event effect experiments is usually 10⁷-10¹¹cm^-2·s^-1Therefore, the multi-blade Faraday cup can meet the requirement of proton single event effect experiments on high fluence rate measurement.In order to avoid weak current loss and interference caused by long-distance transmission, all measuring devices need to be placed nearby on the irradiation device. But considering the radiation safety of the proton experiment, the measuring command is remotely controlled on a computer of a measuring hall through a network.

In order to realize remote control and automatic measurement of the multi-blade Faraday cage, the embodiment of the disclosure further provides a multi-blade Faraday cage measuring system based on the multi-blade Faraday cage. Figure 3 schematically illustrates a block diagram of a multi-leaf faraday cage measurement system in an embodiment of the disclosure.

As shown in fig. 3, a multi-leaf faraday cage measurement system 300 is adapted for atmospheric environment measurements, the system 300 comprising: multi-leaf faraday cup 100, signal acquisition device 310, signal measurement device 320, and controller 330.

The multi-leaf faraday cage 100 includes a plurality of conductors 120 and insulators 110 (shown in fig. 1) arranged alternately, and the conductors 120 and insulators 110 are tightly connected by insulated fasteners 130 to exclude air from the interior of the multi-leaf faraday cage 100. The conductor 120 is used for depositing charges carried by the detected particles in the detected beam current, and the insulator 110 is used for blocking secondary electrons generated on the conductor 120 from diffusing between adjacent conductors.

In the disclosed embodiment, insulated fasteners 130 are used to compress all insulators 110 and conductors 120, allowing air inside multi-lobed faraday cup 100 to vent, thereby reducing or even eliminating the effect of free ions and charged aerosols in the air on the detection background, resulting in a substantial reduction in the background noise. The insulating fastener 130 may be, for example, a fastening structure composed of a screw 131 and a nut 132, or may be fixed by an elastic member, such as an elastic sealing ring, which is not limited herein, as long as it can perform the functions of insulating, sealing, and compressing all conductors and insulators so that air inside the multi-leaf faraday cage can be removed.

In the embodiment of the disclosure, when the material of the conductor 120 is selected, the range deviation caused by the energy divergence and the angle divergence of the measured particles in the material of the conductor 120 is required to meet the measurement accuracy requirement of the multi-leaf faraday cup 100. On the premise that the range deviation caused by energy divergence and angle divergence meets the measurement accuracy requirement, the conductor material can be selected according to the actual requirement (for example, considering the manufacturing cost, the material processing accuracy requirement, the material processing difficulty, the device structure requirement, the safety and the like), for example, if the miniaturization of the multi-blade faraday cylinder is required, the material with large atomic mass number (for example, copper can be selected as the material of the conductor 120) meeting the energy divergence and angle divergence conditions can be adopted, and if the material activation of the conductor 120 needs to be strictly controlled, the material with small atomic mass number (for example, aluminum can be selected as the material of the conductor 120) can be selected as far as possible.

In the embodiment of the disclosure, the copper sheet may be selected as the material of the conductor 120, and the reason for selecting the copper sheet is that the copper sheet meets the requirement of measurement accuracy (for example, the measurement accuracy is greater than or equal to 90% in the energy measurement range of 45-100 MeV), and the material has a large atomic mass number, so that the thickness of the multi-blade faraday cage 100 can be effectively reduced, and the multi-blade faraday cage can be miniaturized, so that the structure of the multi-blade faraday cage measurement system 300 is more compact. The material of the insulator 110 may be, for example, Kapton film made of polyimide, which has good ductility, high temperature resistance and insulation, and can block the diffusion of secondary electrons generated on the conductor 120 between adjacent conductors.

According to the embodiment of the disclosure, the number of layers of the conductor 120 is not more than 36, but the number of layers of the conductor 120 is not limited to the above number of layers, the total number of layers of the conductor 120 can be increased according to the measurement requirement, and the increase of the number of layers of the conductor 120 is beneficial to improving the measurement accuracy of the multi-blade faraday cage 100. If the precision of the multi-blade Faraday cage is to be increased, the thickness of each conductor sheet is required to be reduced, the total layer number is increased, and a more advanced signal acquisition system is adopted to measure more signals. In the disclosed embodiment, the number of layers of the conductor 120 is 36. According to an embodiment of the present disclosure, the thickness of the conductor 120 is less than 500 μm. The thickness of each layer of the conductor 120 is specifically designed and selected according to the measurement requirements, and in the embodiment of the present disclosure, each layer of the conductor 120 is designed to be 500 μm. In the disclosed embodiment, insulator 110 is less than 50 μm thick per layer. The thickness of each layer of the insulator 110 has a small influence on the measurement result, and can be designed and selected according to the actual situation for the insulator 110. In the embodiment of the present disclosure, the number of layers of the insulator 110 may be 37, and each layer of the insulator 110 has a thickness of 50 μm.

Referring to fig. 3, as shown in fig. 3, the signal collecting device 310 is used for collecting the measured beam current signal deposited on the conductor, scanning the measured beam current signal, and outputting a scanning signal.

The signal measuring device 320 is configured to receive the scanning signal output by the signal acquiring device 310, obtain a corresponding current spectrum according to the scanning signal, and output a test value according to a maximum current peak in the current spectrum.

And the controller 330 is used for controlling the signal acquisition device 310 and the signal measurement device 320 to read the measured beam current signal, the scanning signal and the test value.

According to the embodiment of the present disclosure, the signal collecting apparatus 310 includes: a signal switching unit 311 and a signal scanning unit 312. The signal switching unit 311 is electrically connected with an output channel of the conductor 120 in the multi-blade faraday cup 100, and the signal of the measured beam current deposited on the conductor 120 is acquired by controlling the connection of the signal switching unit 311 and the output channel of the conductor 120. The signal scanning unit 312 is configured to receive the measured beam current signal, scan the measured beam current signal, and output a scanning signal.

According to the embodiment of the present disclosure, the signal switching unit 311 includes two layers of switches, where an input terminal of each switch in a first layer of switches controls output channels of two conductors, an input terminal of one switch in a second layer of switches controls output terminals of two switches in the first layer of switches, and output terminals of a plurality of switches in the second layer of switches are connected to channels of the signal scanning unit 312 in a one-to-one correspondence manner.

As shown in fig. 3, the signal switching unit 311 includes two layers of switches, each of the switches (e.g., a 1-a 4 shown in fig. 3) in the first layer can control the output channels (e.g.,

conductor output channels

1 and 10 shown in fig. 3) of the two conductor layers in the multi-leaf faraday cup 100 by switching, the input terminal of one switch (e.g., b1 shown in fig. 3) in the second layer controls the output terminals (e.g., a1 and a2 shown in fig. 3) of the two switches in the first layer, and the output terminals of the switches in the second layer are connected in one-to-one correspondence with the channels of the signal scanning unit 312 (e.g., b1 shown in fig. 3 is connected in correspondence with channel No. 1 of the signal scanning unit 312). Specifically, for example, the switch a1 in the first layer of switches may realize circuit switching between the conductor 1 and the conductor 10, the switch a2 in the first layer of switches may realize circuit switching between the conductor 19 and the conductor 28, and the switch b1 in the second layer of switches may switch and control the paths connected to the switches a1 and a2 in the first layer of switches. The output end of the switch b1 in the second layer of switches is connected to the corresponding first input channel of the signal scanning unit 312, so as to realize the acquisition and scanning of the measured beam current signal on the corresponding conductor (e.g. conductor 1, conductor 10, conductor 19 and conductor 28). It can be seen that, by the above-mentioned switching manner, one of the second layer switches (for example, b1 shown in fig. 3) can control the output channels of the four conductor layers, that is, based on the switching control of the signal switching unit 311, the signal scanning unit 312 only needs 9 corresponding paths to be connected with the output channels corresponding to the 36 layer conductors. Accordingly, all switches in the first layer of switches and all switches in the second layer of switches cooperate to control the detected beam current signals on all 36 layers of conductors 120 in the multi-leaf faraday cup 100 to be sequentially output to the signal scanning unit 312 for acquisition and scanning. The design mode greatly simplifies the circuit control structure, so that the measurement operation is simpler and more convenient.

According to the embodiment of the present disclosure, the signal measuring device 320 includes one or more electrometers, and the electrometers are configured to sequentially receive the scanning signal, obtain a corresponding current spectrum according to the scanning signal, obtain a current maximum peak in the current spectrum within a preset measuring time, and obtain a measured value of the energy of the measured beam current according to the current maximum peak.

In particular, the signal measurement device 320 may be one or more electrometers. In order to simplify the structure of the measurement system, in the embodiment of the present disclosure, the signal measurement device 320 may use an electrometer to implement its function, and specifically, the electrometer is connected to the output end of the signal scanning unit 312. When the signal scanning unit 312 outputs a corresponding scanning signal on the conductor 120 to the electrometer, the electrometer reads a current value corresponding to the scanning signal within a predetermined measurement time. Repeating the above operations until the electrometer receives the scanning signals on all the conductor sheets, so as to obtain an electric current spectrum, then obtaining the maximum current peak value in the electric current spectrum and the position of the conductor 120 corresponding to the maximum current peak value, and measuring the proton energy in a short time through the thickness of the conductor sheet position where the maximum current peak value is located, so as to obtain the measured value.

Fig. 4A, 4B, and 4C schematically illustrate block diagrams of controller structures in a multi-leaf faraday cage measurement system in an embodiment of the disclosure.

As shown in fig. 4A, the controller 330 includes a signal control unit 331 and a data reading unit 332.

The signal control unit 331 is configured to control the signal switching unit 311 to switch the first layer switch and the second layer switch, and transmit the detected beam current signal on the conductor 120 to the signal scanning unit 312; and the control signal scanning unit 312 scans the measured beam current signal; and a control signal measuring device 320 for measuring the scanning signal outputted from the signal scanning unit 312 and outputting the test value. The data reading unit 332 is used for reading the beam stream signal under test, the scan signal and the test value.

As shown in fig. 4B, the controller 330 further includes a display unit 333 for displaying the measured beam current signal, the scan signal, and the test value according to the embodiment of the present disclosure. Specifically, during the test process, the operator can know the progress of the measurement through the test data displayed by the display unit 333 to follow the measurement process in real time.

As shown in fig. 4C, the controller 330 further includes a storage unit 334 for storing the measured beam current signal, the scan signal, and the test value according to the embodiment of the present disclosure.

Compared with the prior art, the multi-blade Faraday cylinder measuring system provided by the disclosure has the advantages of simple structure, small occupied space, capability of realizing automatic measurement of proton beam current in different energy ranges in an atmospheric environment, guarantee of the safety of the measuring process, and convenience and rapidness in operation.

As shown in fig. 5, the method of operating the multi-leaf faraday cage measurement system includes the steps of:

in step S1, when the energy of the measured beam current is completely deposited in the multi-leaf faraday cup 100, outputting a first signal to control the two-layer switch to the path corresponding to the first conductor, collecting and scanning the measured beam current signal on the first conductor, and outputting a first scanning signal; the above operations are repeatedly executed until the acquisition and scanning of the measured beam current signals on all the conductors are completed.

In step S2, the output second signal controls the signal measuring device 320 to sequentially receive the scanned signals output after scanning the beam current signals to be measured on all conductors, obtain the corresponding current spectrum, and output the test value according to the maximum peak value of the current in the current spectrum.

In order to make the technical solution of the present disclosure more clearly understood by those skilled in the art, the technical solution of the multi-leaf faraday cage measuring system of the present disclosure will be described below with reference to specific embodiments.

Examples

The structure of the multi-blade faraday cage measurement system is shown in fig. 3, wherein the structure of the multi-blade faraday cage 100 in the multi-blade faraday cage measurement system 300 is shown in fig. 1. The multi-leaf faraday cage 100 adopts a copper sheet as a material of the conductor 120, the number of layers of the conductor 120 is set to 36, and the thickness of each layer of the conductor 120 is 500 μm. The insulator 110 is made of Kapton film with a thickness of 50 μm per layer. Wherein all conductors 120 and insulators 110 are tightly connected by insulated fasteners 130 to exclude air from inside the multi-leaf faraday cage 100. The energy measurement range of the multi-blade Faraday cup 100 is 0-100 MeV, and the measurement precision in the energy measurement range of 45-100 MeV is greater than or equal to 90%.

Under the atmospheric environment, the multi-blade faraday cage measuring system 300 is used for measuring the proton beam energy of a proton single event effect irradiation experimental device in a proton cyclotron, the initial proton energy of the accelerator is fixed at 100MeV in the experimental process, six energy points of 45MeV, 50MeV, 60MeV, 70MeV, 80MeV and 90MeV are measured by fast energy switching of a scattering target and an energy reduction sheet, and the measured data are fitted to obtain a current spectrum shown in fig. 6.

Figure 6 shows the measurement of different proton energies using a multi-leaf faraday cup measurement system in an embodiment of the disclosure.

As shown in fig. 6, the maximum current peak and the position of the conductor sheet where the maximum current peak is located are obtained from the current spectrum corresponding to each energy point, and then the measured value is obtained by calculation according to the thickness of the conductor sheet where the maximum current peak is located and the maximum current peak. Specifically, the results of the measurement of six energy points of 45MeV, 50MeV, 60MeV, 70MeV, 80MeV and 90MeV are shown in table one. The theoretical energy values shown in table one are calculated by using a monte carlo program.

Watch 1

As can be seen from the comparison of the data in the table, the deviation of the actual value and the theoretical value measured by the multi-blade Faraday cup measuring system in the disclosure is within 10%, and the design requirements are met.

The embodiments of the present disclosure have been described above. However, these examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Although the embodiments are described separately above, this does not mean that the measures in the embodiments cannot be used in advantageous combination. The scope of the disclosure is defined by the appended claims and equivalents thereof. Various alternatives and modifications can be devised by those skilled in the art without departing from the scope of the present disclosure, and such alternatives and modifications are intended to be within the scope of the present disclosure.

Claims

1. A multi-leaf faraday cup adapted for atmospheric environment measurements, the multi-leaf faraday cup (100) comprising:

a plurality of conductors (120) and insulators (110) arranged alternately, the conductors (120) and insulators (110) being closely connected by insulated fasteners (130), the fasteners (130) being for compressing the insulators (110) and conductors (120) to expel air inside the multi-lobed faraday cage (100);

wherein the conductor (120) is used for depositing the charges carried by the particles to be detected in the detected beam current, and the insulator (110) is used for blocking the secondary electrons generated on the conductor (120) from diffusing between the adjacent conductors;

the insulator (110) is made of a malleable insulating material.

2. The multi-leaf Faraday cage of claim 1,

when the energy of the detected particle is larger, or when the capability of preventing the detected particle is required to be stronger, the conductor (120) is made of a material with a larger atomic mass number;

the conductor (120) is made of a material with a smaller atomic mass number when the energy or angle divergence of the detected particles in the conductor (120) is larger, or when the material of the conductor (120) is activated to a larger extent.

3. The multi-leaf faraday cage of claim 2, wherein the conductor (120) is comprised of a material comprising copper, aluminum, iron, or cadmium.

4. The multi-leaf faraday cage of claim 1, wherein the insulator (110) is of an insulating material having high temperature resistance.

5. The multi-leaf faraday cage of claim 4, wherein an insulating material used for the insulator (110) is polyimide.

6. The multi-leaf faraday cage of claim 5, wherein the insulator (110) is a Kapton film made of polyimide.

7. A multi-leaf faraday cup measurement system adapted for atmospheric environment measurements, the multi-leaf faraday cup measurement system (300) comprising:

a multi-leaf faraday cage (100) comprising a plurality of alternating conductors (120) and insulators (110), the conductors (120) and insulators (110) being tightly connected by insulated fasteners (130), the fasteners (130) being used to compress the insulators (110) and conductors (120) to expel air inside the multi-leaf faraday cage (100); wherein the conductor (120) is used for depositing the charges carried by the particles to be detected in the detected beam current, and the insulator (110) is used for blocking the secondary electrons generated on the conductor (120) from diffusing between the adjacent conductors; the insulator (110) is made of a malleable insulating material;

the signal acquisition device (310) is used for acquiring a measured beam current signal deposited on the conductor (120), scanning the measured beam current signal and outputting a scanning signal;

the signal measuring device (320) is used for receiving the scanning signal output by the signal acquisition device (310), acquiring a corresponding current spectrum according to the scanning signal, and then outputting a test value according to the maximum current peak value in the current spectrum;

a controller (330) for controlling the signal acquisition device (310) and the signal measurement device (320) to read the measured beam current signal, the scan signal and the test value.

8. The multi-leaf faraday cup measurement system of claim 7, wherein the signal acquisition arrangement (310) comprises:

the signal switching unit (311) is electrically connected with an output channel of the conductor (120) in the multi-blade Faraday cage (100), and the signal switching unit (311) is controlled to be connected with the output channel of the conductor (120) so as to realize the acquisition of the measured beam current signal deposited on the conductor (120);

and the signal scanning unit (312) is used for receiving the measured beam flow signal, scanning the measured beam flow signal and outputting a scanning signal.

9. The multi-leaf faraday cup measurement system of claim 8, wherein the signal switching unit (311) comprises two layers of switches, wherein an input of each switch in a first layer of switches switchably controls output channels of two of the conductors, an input of one switch in a second layer of switches switchably controls outputs of two switches in the first layer of switches, and outputs of a plurality of switches in the second layer of switches are connected in one-to-one correspondence with channels of the signal scanning unit.

10. The multi-leaf faraday cup measurement system of claim 7, wherein the signal measurement apparatus (320) comprises one or more electrometers for sequentially receiving the scanning signal, obtaining a corresponding current spectrum from the scanning signal, obtaining a maximum peak current value in the current spectrum within a predetermined measurement time, and obtaining a measurement of the energy of the measured beam current from the maximum peak current value.

11. The multi-leaf faraday cup measurement system of claim 8, wherein the controller (330) comprises:

a signal control unit (331) for controlling the signal switching unit (311) to switch a first layer switch and a second layer switch and transmitting the measured beam current signal on the conductor (120) to the signal scanning unit (312); and controlling the signal scanning unit (312) to scan the measured beam current signal; and controlling the signal measuring device (320) to measure the scanning signal output by the signal scanning unit (312) and output the test value;

a data reading unit (332) for reading the measured beam current signal, the scanning signal and the test value.

12. The multi-leaf faraday cup measurement system of claim 11, wherein the controller (330) further comprises a display unit (333) for displaying the measured beam flow signal, the scan signal and the test value.

13. The multi-leaf faraday cup measurement system of claim 11, wherein the controller (330) further comprises a memory unit (334) for storing the measured beam flow signal, the scan signal and the test value.

14. A method of measuring different proton energies using the multi-leaf faraday cup measurement system of claim 7, comprising:

when the energy of the measured beam current is completely deposited in the multi-blade Faraday cage (100), outputting a first signal to control a two-layer selector switch to be switched to a passage corresponding to a first conductor, collecting and scanning the measured beam current signal on the first conductor, and outputting a first scanning signal; repeatedly executing the operations until the acquisition and scanning of the measured beam current signals on all the conductors are completed;

and outputting a second signal to control the signal measuring device (320) to sequentially receive scanning signals output by scanning the measured beam current signals on all conductors, acquiring a corresponding current spectrum, and outputting a test value according to the maximum current peak value in the current spectrum.