Large-area beam stray monitoring device and method

Abstract

The invention relates to a large-area beam stray monitoring device and method. The device comprises a tungsten filament, a fixed insulating block, a tension spring, an aviation plug and a signal acquisition system. The tungsten filament is used for receiving bombardment of stray beams and generating weak current; the fixed insulating block is used for isolating the neutralizer and the tungsten filament; the tension spring is used for adjusting the tightness of the tungsten filament to prevent the tungsten filament from being heated and bent; the aviation plug is used for transmitting a collected electric signal to the outside of the vacuum chamber; the signal acquisition system is composed of a low-resistance resistor, a voltage measuring device, a pre-amplifier, an analog-to-digital converter (ADC), a microcontroller (MCU) and an upper computer, and can accurately and rapidly output electric signals to a display device. According to the invention, large-area beam stray real-time monitoring is realized through a resistance sampling method.

Description

Technical Field

[0001] The invention relates to the technical field of ion beam spread monitoring, and in particular to a large-area beam stray monitoring device and method. Background Art

[0002] Neutral beam injection is an effective means of heating and current driving for fusion plasma. It has the typical characteristics of clear physical mechanism and direct and significant heating effect. It not only provides indispensable, direct and effective support for the current fusion experimental device to carry out high-level physical experiments near the core, but also is the most effective tool for the proposed fusion reactor to achieve fusion ignition and burning plasma control. At present, the most commonly used neutral beam injection systems in the world are the neutral beam injection system based on positive ion source and the neutral beam injection system based on negative ion source. With the continuous increase in the size of fusion devices and the continuous improvement of fusion plasma parameters, the beam energy of the neutral beam injection system is required to increase from tens of kev to Mev level. Since the neutralization efficiency of the neutral beam injection system based on positive ion source will drop sharply with the increase of particle energy, from the efficiency of the ion neutralization process of the neutral beam injection system and the economy of the whole system, when the required beam energy exceeds 50kev / amu, the neutral beam injection system based on negative ion source (Negtive ion based NeutralBeam Injection system) should generally be considered.

[0003] As a key component of beam neutralization, the main function of the neutralizer is to form and maintain a gas target with a certain density distribution in the beam channel, thereby achieving the neutralization of the negative ion beam. The neutralizer inlet is designed to be equipped with a beam limiter, which, together with the inner wall of the neutralizer beam channel, intercepts and absorbs the overly divergent negative ion beam emitted by the beam source. When a high-energy negative ion beam bombards the beam channel entrance of the neutralizer, it will cause the neutralizer to fail. Therefore, it is of great significance to design a neutral beam divergence monitoring device at the front end of the neutralizer. Summary of the invention

[0004] The purpose of the present invention is to monitor the neutral beam stray beam in real time, avoid the neutral beam directly bombarding the beam inlet of the neutralizer and causing the failure of the neutralizer material, and provide a large-area beam stray monitoring device and method.

[0005] The technical solution of the present invention is: a large-area beam stray monitoring device, the device comprising a tungsten wire, an insulating fixing block, a tension spring, an aviation plug, and a signal acquisition system;

[0006] The tungsten wire is used to receive the bombardment of the neutral beam and generate an electrical signal;

[0007] The insulating fixing block is used to isolate the neutralizer from the tungsten wire and provide insulation protection for the electrical signal obtained by the tungsten wire;

[0008] The tension spring acts to tighten the tungsten wire to prevent the tungsten wire from being heated and bent under the bombardment of the neutral beam divergence;

[0009] The aviation plug is used to guide the electrical signal on the tungsten wire out of the vacuum chamber, and the aviation plug is fixed on the outer wall of the vacuum chamber without destroying the vacuum degree of the vacuum chamber;

[0010] The signal acquisition system is used to acquire the electrical signal on the tungsten wire.

[0011] The present invention also provides a large-area beam stray monitoring method, comprising the following steps:

[0012] S1: two insulating fixed blocks are arranged on the left and right sides of the neutralizer beam inlet, and the insulating fixed blocks are symmetrically distributed on the upper and lower sides of the neutralizer inlet; the two insulating fixed blocks symmetrically arranged on the upper and lower sides are called a group, and there are three groups on each side of the neutralizer;

[0013] S2: A tension spring is installed on each of the three groups of insulating fixing blocks to adjust the tightness of the tungsten wire installed on the tension spring;

[0014] S3: Tungsten wires are installed on the tension springs, and a low-resistance resistor is connected in series to each group of tungsten wires. The current is calculated according to the voltage drop generated by the current passing through the resistor. The three groups of tungsten wires are distributed at a certain distance, and the neutral beam stray beam intensity is obtained based on the tungsten wires.

[0015] S4: The end of the tungsten wire is connected to a signal acquisition system, and the signal acquisition system is connected to an aviation plug, which is fixed outside the beam line vacuum chamber to transmit the neutral beam stray beam obtained by the tungsten wire to the beam line vacuum chamber;

[0016] S5: The signal acquisition system includes a low-resistance resistor, a preamplifier, a voltage measuring device, an analog-to-digital converter ADC, a microcontroller MCU and an upper computer position; the low-resistance resistor is used to convert the current signal into a voltage signal for subsequent processing; the preamplifier is used to amplify the weak voltage signal output by the low-resistance resistor, increase the amplitude of the voltage signal, and filter and denoise the signal; the voltage measuring device is used to measure the voltage signal of the low-resistance resistor; the analog-to-digital converter ADC is used to convert the analog signal into a digital signal for computer processing; the microcontroller MCU is responsible for data acquisition, processing and control; the upper computer position is responsible for data display and control.

[0017] The beneficial effects of the present invention are:

[0018] By setting three groups of tungsten wires on the left and right sides of the neutralizer beam entrance, and separating the tungsten wires from the neutralizer with insulating materials, the signal acquisition system is used to collect the stray beam signal of the neutral beam hitting the tungsten wire, and the collected electrical signal is transmitted to the outside of the vacuum chamber through the aviation plug. By analyzing the collected electrical signals and monitoring the beam divergence in real time, it helps researchers to adjust the beam parameters in time to ensure the stability and control accuracy of the beam; by real-time monitoring of the beam divergence, the geometric convergence angle of the beam and the divergence angle of the ion source can be optimized to improve the neutral beam power conversion efficiency; real-time monitoring of the neutral beam divergence can prevent the neutral beam from directly bombarding the neutralizer, causing the neutralizer material failure, and extending the service life of the neutralizer. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the present invention;

[0020] Figure 2 It is a connection diagram of the signal acquisition system of the present invention;

[0021] Figure 3 It is a schematic diagram of the structure of the insulating fixing block.

[0022] Among them, 1. Insulating fixing block, 2. Tension spring, 3. Tungsten wire, 4. Low resistance resistor, 5. Signal acquisition system. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other. To achieve the above-mentioned purpose, the present invention adopts the following technical scheme.

[0024] See also Figure 1 , This embodiment provides a large-area beam stray monitoring device for monitoring the beam stray at the entrance of a neutralizer, the device comprises an insulating fixing block 1, a tension spring 2, a tungsten wire 3, an aviation plug, and a signal acquisition system 5;

[0025] The tungsten wire 3 is used to measure the beam spread of stray high-energy charged particles:

[0026] The insulating fixing block 1 is used to connect the neutralizer inlet and the tungsten wire 3, and the insulating fixing block 1 plays an insulating and protective role for the tungsten wire 3;

[0027] The tension spring 2 connects the insulating fixing block 1 and the tungsten wire 3, and the tension spring 2 can adjust the tightness of the tungsten wire 3 to prevent the tungsten wire from being deformed by heat under the bombardment of the neutral beam divergence;

[0028] The aviation plug is used to conduct the electrical signal on the tungsten wire 3 out of the vacuum chamber. At the same time, the aviation plug can be fixed on the outer wall of the vacuum chamber without destroying the vacuum degree of the vacuum chamber.

[0029] The signal acquisition system 5 is used to obtain the current signal on the tungsten filament 3 to monitor the beam strayness over a large area.

[0030] The tungsten wire 3 has a diameter of 0.5 mm and a length of 1400 mm. By being bombarded by a stray beam, a current signal of the stray beam is obtained. The current signal will change with the change in the degree of beam stray, thereby realizing the monitoring of large-area beam strays, improving the accuracy of beam monitoring, protecting the entrance of the neutralizer, and avoiding material failure at the entrance of the neutralizer.

[0031] like Figure 3 As shown, the insulating fixing block 1 is a rectangular parallelepiped structure. A convex column with a through hole is provided on one side of the insulating fixing block 1. A ring is placed on the through hole. The ring is connected to the tension spring 2. Considering the insulation requirements, high-density polyethylene is selected as the insulating fixing block material.

[0032] The tension spring 2 is a small-sized double-hook tension spring, which is used to adjust the tightness of the tungsten wire to prevent the tungsten wire from being bent due to heat under the bombardment of the neutral beam, thereby achieving an adjustable tightness effect of the tungsten wire.

[0033] The aviation plug is a circular aviation plug, which is plugged into the housing by a positive contact (pin) and a negative contact (socket), and is fixed to the outside of the vacuum chamber by an M4 bolt. The aviation plug is used to transmit the electrical signal on the tungsten wire to the outside of the vacuum chamber.

[0034] like Figure 2 As shown, the signal acquisition system 5 includes a low-resistance resistor 4, a preamplifier, a voltage measuring device, an analog-to-digital converter ADC, a microcontroller MCU, and a host computer. The low-resistance resistor is used to convert the current of the stray beam hitting the tungsten wire 3 into an electrical signal; the preamplifier is used to zero, amplify, and filter the electrical signal; the ADC is used to convert the analog signal into a digital signal; the voltage measuring device is used to measure the voltage signal of the low-resistance resistor; the microcontroller MCU is used to process data and send the data to the host computer; the host computer is used to process data and display and control.

[0035] The present invention also provides a large-area beam stray monitoring method, comprising the following steps:

[0036] S1: two insulating fixed blocks 1 are arranged on the left and right sides of the neutralizer beam inlet, and the insulating fixed blocks 1 are symmetrically distributed on the upper and lower sides of the neutralizer inlet; the two insulating fixed blocks 1 symmetrically arranged on the upper and lower sides are called a group, and there are three groups on each side of the neutralizer;

[0037] S2: A tension spring 2 is installed on each of the three groups of insulating fixing blocks 1 to adjust the tightness of the tungsten wire 3 installed on the tension spring 2;

[0038] S3: Tungsten wires 3 are installed on the tension spring 2, and a low-resistance resistor is connected in series to each group of tungsten wires 3. The current is calculated according to the voltage drop generated by the current passing through the resistor. The three groups of tungsten wires 3 are distributed at a certain distance, and the neutral beam stray beam intensity is obtained based on the tungsten wires 3;

[0039] S4: The end of the tungsten wire 3 is connected to a signal acquisition system 5, and the signal acquisition system 5 is connected to an aviation plug, which is fixed outside the beam line vacuum chamber to transmit the neutral beam stray beam obtained by the tungsten wire 3 to the beam line vacuum chamber;

[0040] S5: The signal acquisition system 5 includes a low-resistance resistor 4, a preamplifier, a voltage measuring device, an analog-to-digital converter ADC, a microcontroller MCU and an upper computer position; the low-resistance resistor is used to convert the current signal into a voltage signal for subsequent processing; the preamplifier is used to amplify the weak voltage signal output by the low-resistance resistor to increase the amplitude of the voltage signal, and can also filter and denoise the signal to improve the quality and stability of the acquired signal; the voltage measuring device is used to measure the voltage signal of the low-resistance resistor; the analog-to-digital converter ADC is used to convert the analog signal into a digital signal for computer processing; the microcontroller MCU is responsible for data acquisition, processing and control of each module; the upper computer position is responsible for data display and control.

[0041] In this embodiment, the tungsten wire 3 is bombarded by the neutral beam divergence to obtain the current signal. If the neutral beam divergence changes, the current signal will also change accordingly. The signal acquisition system 5 collects, amplifies, filters, and performs a series of operations on the current signal to display the current signal on the upper machine position, thereby realizing real-time monitoring of the neutral beam divergence.

[0042] The neutral beam stray current monitoring obtains the required current through a resistance sampling method, thereby realizing the monitoring of the beam stray current.

[0043] Based on the resistance sampling method, a low-resistance resistor 4 with a precisely known resistance value is used and connected in series in the circuit. The resistance of the low-resistance resistor 4 is very small to ensure that it has little effect on the current flow in the circuit.

[0044] Use a high-precision multimeter or dedicated voltage measuring equipment to measure the voltage drop across the low-resistance resistor 4 and record it as V drop .

[0045] Based on the measured voltage drop and the known resistance value of the low-resistance resistor 4, Ohm's law is used to calculate the current flowing through the resistor. The calculation formula is:

[0046] ,

[0047] Where, I is the current flowing through the low resistance resistor 4, V drop is the voltage drop across the low-resistance resistor 4, R shunt is the resistance value of the low-resistance resistor 4.

[0048] In this embodiment, since the voltage drop across the low-resistance resistor 4 is very small, a preamplifier is needed to amplify the signal so as to enable more accurate measurement by the analog-to-digital converter ADC.

[0049] The analog-to-digital converter ADC is used to convert the amplified voltage signal into a digital signal so as to be processed by a digital system.

[0050] The microcontroller MCU is used to process the digital signal converted by the analog-to-digital converter ADC, perform calculations, store data and perform real-time control.

[0051] The upper machine position is used to store the measurement data and output the processed data to the display device.

[0052] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art may make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A large-area beam stray monitoring device, characterized in that: The device includes a tungsten wire, an insulating fixing block, a tension spring, an aviation plug, and a signal acquisition system; The tungsten wire is used to receive the bombardment of the neutral beam and generate an electrical signal; The insulating fixing block is used to isolate the neutralizer from the tungsten wire and provide insulation protection for the electrical signal obtained by the tungsten wire; The tension spring acts to tighten the tungsten wire to prevent the tungsten wire from being heated and bent under the bombardment of the neutral beam divergence; The aviation plug is used to guide the electrical signal on the tungsten wire out of the vacuum chamber, and the aviation plug is fixed on the outer wall of the vacuum chamber without destroying the vacuum degree of the vacuum chamber; The signal acquisition system is used to acquire the electrical signal on the tungsten wire.

2. The large-area beam stray monitoring device according to claim 1, characterized in that: The tungsten wires are distributed on the left and right sides of the neutralizer entrance, with three groups arranged at certain intervals on each side. High-energy charged particles bombard the tungsten wires to generate weak electrical signals.

3. The large-area beam stray monitoring device according to claim 1, characterized in that: The insulating fixing block is a rectangular parallelepiped structure. A convex column with a through hole is provided on one side of the insulating fixing block. A circular ring is sleeved on the through hole. The circular ring is connected to the tension spring. High-density polyethylene is selected as the insulating fixing block material.

4. The large-area beam stray monitoring device according to claim 1, characterized in that: The tension spring is a double-hook spring used to connect the insulating fixing block and the tungsten wire.

5. The large-area beam stray monitoring device according to claim 1, characterized in that: The aviation plug is a circular aviation plug, which is plugged and connected on the shell by a positive contact and a negative contact, and is fixed on the outside of the vacuum chamber by bolts.

6. The large-area beam stray monitoring device according to claim 1, characterized in that: The signal acquisition system includes a low-resistance resistor, a voltage measuring device, a preamplifier, an analog-to-digital converter ADC, a microcontroller MCU and an upper machine position. The low-resistance resistor is connected in series with a tungsten filament. The voltage measuring device is used to measure the voltage signal of the low-resistance resistor. The preamplifier is used to amplify the voltage signal of the voltage measuring device. The analog-to-digital converter ADC converts the amplified voltage signal into a digital signal. The microcontroller MCU is used to process the digital signal converted by the analog-to-digital converter ADC, perform calculations, and store data. The upper machine position is used for real-time monitoring and data acquisition.

7. A large-area beam stray monitoring method, characterized in that: The following steps are involved: S1: two insulating fixed blocks are arranged on the left and right sides of the neutralizer beam inlet, and the insulating fixed blocks are symmetrically distributed on the upper and lower sides of the neutralizer inlet; the two insulating fixed blocks symmetrically arranged on the upper and lower sides are called a group, and there are three groups on each side of the neutralizer; S2: A tension spring is installed on each of the three sets of insulating fixing blocks to adjust the tightness of the tungsten wire installed on the tension spring; S3: Tungsten wires are installed on the tension springs, and a low-resistance resistor is connected in series to each group of tungsten wires. The current is calculated according to the voltage drop generated by the current passing through the resistor. The three groups of tungsten wires are distributed at a certain distance, and the neutral beam stray beam intensity is obtained based on the tungsten wires. S4: The end of the tungsten wire is connected to a signal acquisition system, and the signal acquisition system is connected to an aviation plug, which is fixed outside the beam line vacuum chamber to transmit the neutral beam stray beam obtained by the tungsten wire to the beam line vacuum chamber; S5: The signal acquisition system includes a low-resistance resistor, a preamplifier, a voltage measuring device, an analog-to-digital converter ADC, a microcontroller MCU and an upper computer position; the low-resistance resistor is used to convert the current signal into a voltage signal for subsequent processing; the preamplifier is used to amplify the weak voltage signal output by the low-resistance resistor, increase the amplitude of the voltage signal, and filter and denoise the signal; the voltage measuring device is used to measure the voltage signal of the low-resistance resistor; the analog-to-digital converter ADC is used to convert the analog signal into a digital signal for computer processing; the microcontroller MCU is responsible for data acquisition, processing and control; the upper computer position is responsible for data display and control.

8. A large-area beam stray monitoring method according to claim 7, characterized in that: The neutral beam stray current monitoring obtains the required current through a resistance sampling method, thereby realizing the monitoring of the beam stray current; The resistance sampling method is to use a low-resistance resistor with a known resistance value and connect it in series in the circuit. The resistance of the low-resistance resistor is small, so that it has little effect on the current flow in the circuit; Use a voltage measuring device to measure the voltage drop across a low-value resistor and record it as V drop ; Based on the measured voltage drop and the known resistance of the low-value resistor, Ohm's law is used to calculate the current flowing through the resistor: ， Where I is the current flowing through the low-value resistor, V drop is the voltage drop across the low-value resistor, R shunt is the resistance value of the low-value resistor.

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