A large area beam halo monitoring device and method

Abstract

The present application relates to a kind of large-area beam stray monitoring device and method, device includes tungsten wire, fixed insulating block, tension spring, aviation plug and signal acquisition system.Tungsten wire is used to accept the bombardment of stray beam and generate weak current;Fixed insulating block is used to isolate neutralizer and tungsten wire, and tension spring is used to adjust the degree of tightness of tungsten wire to prevent tungsten wire from being bent by heat;The aviation plug is used to transmit the collected electric signal to the outside of vacuum chamber;The signal acquisition system is composed of low resistance resistance, voltage measuring device, preamplifier, analog-digital converter ADC, microcontroller MCU and host computer, and electric signal can be accurately and quickly output to display device.The present application realizes large-area beam stray real-time monitoring by resistance sampling method.

Description

Technical Field

[0001] This invention relates to the field of ion beam stray beam monitoring technology, and in particular to a large-area beam stray beam monitoring device and method. Background Technology

[0002] Neutral beam injection is an effective heating and current-driven method for fusion plasma, characterized by a clear physical mechanism and direct and significant heating effects. It not only provides essential and effective support for high-level near-core physics experiments in current fusion experimental devices, but is also the most effective tool for achieving fusion ignition and combustion plasma control in proposed fusion reactors. Currently, the most commonly used neutral beam injection systems worldwide are those based on positive ion sources and those based on negative ion sources. With the continuous increase in the size of fusion devices and the continuous improvement of fusion plasma parameters, the required beam energy of neutral beam injection systems has increased from tens of keV to the MeV level. Since the neutralization efficiency of neutral beam injection systems based on positive ion sources decreases sharply with increasing particle energy, considering the efficiency of the ion neutralization process and the overall system economy, when the required beam energy exceeds 50 keV / amu, a neutral beam injection system based on a negative ion source should generally be considered.

[0003] The neutralizer, as a key component for beam neutralization, primarily functions to form and maintain a gas target with a certain density distribution within the beam channel, thereby achieving the neutralization of the negative ion beam. A beam limiter is installed at the neutralizer inlet, which, together with the inner wall of the beam channel, intercepts and absorbs excessively divergent negative ion beams emitted from the beam source. When a high-energy negative ion beam bombards the neutralizer's beam channel inlet, it will cause the neutralizer to fail. Therefore, designing a neutral beam divergence monitoring device at the front end of the neutralizer is of great significance. Summary of the Invention

[0004] The purpose of this invention is to monitor stray beams in the neutral beam in real time, prevent the neutral beam from directly bombarding the beam inlet of the neutralizer and causing failure of the neutralizer material, and to provide a large-area stray beam 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 filament is used to receive electrical signals generated by neutral beam scattering.

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

[0008] The tension spring tightens the tungsten wire, preventing it from bending due to heat under the bombardment of the neutral bundle.

[0009] The aviation plug is used to export the electrical signal on the tungsten filament to the vacuum chamber, while the aviation plug is fixed to the outer wall of the vacuum chamber without damaging the vacuum level of the vacuum chamber.

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

[0011] This invention also provides a method for monitoring stray beams over a large area, comprising the following steps:

[0012] S1: Two insulating fixing blocks are set on each of the left and right sides of the neutralizer beam inlet. The insulating fixing blocks are symmetrically distributed on the upper and lower sides of the neutralizer inlet. The two symmetrical insulating fixing blocks are called a group, and there are three groups on each side of the neutralizer.

[0013] S2: Install a tension spring on each of the three sets of insulating fixing blocks to adjust the tension of the tungsten wire installed on the tension spring;

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

[0015] S4: The end of the tungsten wire is connected to a signal acquisition system, which is connected to an aviation plug. The aviation plug is fixed outside the beamline vacuum chamber and transmits the neutral stray beam current acquired by the tungsten wire to the beamline 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 a host computer. The low-resistance resistor converts the current signal into a voltage signal for subsequent processing. The preamplifier amplifies the weak voltage signal output by the low-resistance resistor, increasing the amplitude of the voltage signal, and also filters and denoises the signal. The voltage measuring device measures the voltage signal from the low-resistance resistor. The ADC converts the analog signal into a digital signal for computer processing. The MCU is responsible for data acquisition, processing, and control. The host computer is responsible for data display and control.

[0017] The beneficial effects of this invention are:

[0018] By placing three sets of tungsten filaments on the left and right sides of the neutralizer beam inlet and separating them with insulating material, a signal acquisition system collects the stray neutral beam signal striking the tungsten filaments and transmits the collected electrical signal to the outside of the vacuum chamber via an aviation connector. Real-time monitoring of beam divergence by analyzing the collected electrical signal helps researchers adjust beam parameters promptly, ensuring beam stability and control precision. Real-time monitoring of beam divergence allows for optimization of the beam's geometric convergence angle and ion source divergence angle, improving the neutral beam power conversion efficiency. Furthermore, real-time monitoring of neutral beam divergence prevents direct bombardment of the neutralizer by the neutral beam, avoiding material failure and extending the neutralizer's lifespan. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the present invention;

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

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

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

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other. To achieve the above objectives, this invention adopts the following technical solution.

[0024] Please see Figure 1 This embodiment provides a large-area beam stray monitoring device for monitoring beam straying at the neutralizer inlet. The device includes 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 divergence 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 at the same time, the insulating fixing block 1 provides insulation protection for the tungsten wire 3.

[0027] The tension spring 2 connects the insulating fixing block 1 and the tungsten wire 3. At the same time, the tension spring 2 can adjust the tension of the tungsten wire 3 to prevent the tungsten wire from being deformed by heat under the bombardment of the neutral bundle.

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

[0029] The signal acquisition system 5 is used to acquire the current signal on the tungsten filament 3 to monitor the large-area beam stray dispersion.

[0030] The tungsten wire 3 has a diameter of 0.5 mm and a length of 1400 mm. By receiving the bombardment of stray beams, it obtains the current signal of the stray beam. The current signal will change with the degree of beam straying, thereby realizing the monitoring of large-area beam straying, 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 has a cuboid-like structure. One side of the insulating fixing block 1 has a protruding post with a through hole. A ring is fitted on the through hole and the ring is connected to the tension spring 2. Considering the insulation requirements, high-density polyethylene is selected as the material of the insulating fixing block.

[0032] The tension spring 2 is a small-sized double-hook tension spring used to adjust the tension of the tungsten wire, preventing the tungsten wire from bending due to heat under the bombardment of the neutral beam, thus achieving an adjustable tension effect for the tungsten wire.

[0033] The aviation connector is a circular aviation connector. The circular aviation connector is assembled on the outer shell by male contacts (pins) and female contacts (sockets) and is fixed to the outside of the vacuum chamber by M4 bolts. The aviation connector 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 acts as a shunt resistor to convert the current from stray beams hitting the tungsten filament 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 from the low-resistance resistor. The MCU processes the data and sends it to the host computer. The host computer processes, displays, and controls the data.

[0035] This invention also provides a method for monitoring stray beams over a large area, comprising the following steps:

[0036] S1: Two insulating fixing blocks 1 are set on the left and right sides of the neutralizer beam inlet. The insulating fixing blocks 1 are symmetrically distributed on the upper and lower sides of the neutralizer inlet. The two symmetrical insulating fixing blocks 1 are called a group, and there are three groups on each side of the neutralizer.

[0037] S2: Install a tension spring 2 on each of the three sets of insulating fixing blocks 1 in order to adjust the tension of the tungsten wire 3 installed on the tension spring 2;

[0038] S3: Tungsten wires 3 are installed on the tension spring 2. A low-resistance resistor is connected in series with each group of tungsten wires 3. The current is calculated based on the voltage drop generated by the current passing through the resistor. The three groups of tungsten wires 3 are distributed at a certain distance. The intensity of the neutral beam stray current 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, which is connected to an aviation plug. The aviation plug is fixed outside the beam vacuum chamber and transmits the neutral stray beam current acquired by the tungsten wire 3 to the beam 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 a host computer. The low-resistance resistor converts the current signal into a voltage signal for subsequent processing. The preamplifier amplifies the weak voltage signal output by the low-resistance resistor, increasing the amplitude of the voltage signal. It also filters and denoises the signal, improving the quality and stability of the acquired signal. The voltage measuring device measures the voltage signal from the low-resistance resistor. The ADC converts the analog signal into a digital signal for computer processing. The MCU is responsible for data acquisition, processing, and control of the various modules. The host computer is responsible for data display and control.

[0041] In this embodiment, a current signal is obtained by receiving the bombardment of neutral beam dispersion through tungsten wire 3. If the neutral beam dispersion changes, the current signal will also change accordingly. The current signal is acquired, amplified, filtered and other operations are performed by the signal acquisition system 5 and then displayed on the host computer, thereby realizing real-time monitoring of neutral beam dispersion.

[0042] The neutral beam stray current monitoring obtains the required current through resistance sampling, thereby realizing the monitoring of 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 a dedicated voltage measuring device 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, the current flowing through the resistor is calculated using Ohm's law. The formula is as follows:

[0046] ,

[0047] Where I is the current flowing through the low-resistance resistor 4, and V drop It is the voltage drop across the low-resistance resistor 4, R shunt It 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 that it can be measured more accurately 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 for processing by a digital system.

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

[0051] The host computer is used to save the measurement data and output the processed data to the display device.

[0052] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A large area beam current stray monitoring device, characterized by: The device includes a tungsten wire, an insulating fixing block, a tension spring, an aviation plug, and a signal acquisition system; The tungsten filament is used to receive electrical signals generated by neutral beam scattering. The insulating fixing block is used to isolate the neutralizer from the tungsten wire and to provide insulation protection for the electrical signal acquired by the tungsten wire. The tension spring tightens the tungsten wire, preventing it from bending due to heat under the bombardment of the neutral bundle. The aviation plug is used to export the electrical signal on the tungsten filament to the vacuum chamber, while the aviation plug is fixed to the outer wall of the vacuum chamber without damaging the vacuum level of the vacuum chamber. The signal acquisition system is used to acquire electrical signals from the tungsten filaments. The tungsten filaments are distributed on the left and right sides of the neutralizer inlet, with three groups on each side arranged at a certain interval. High-energy charged particles bombard the tungsten filaments to generate weak electrical signals. The insulating fixing block has a cuboid structure. One side of the insulating fixing block has a protruding post with a through hole. A ring is fitted on the through hole, and the ring is connected to a tension spring. High-density polyethylene is selected as the material for the insulating fixing block.

2. The large area beam current monitoring device of claim 1, wherein: The tension spring is a double-hook spring, used to connect the insulating fixing block and the tungsten wire.

3. The large area beam current monitoring device of claim 1, wherein: The aviation plug is a circular aviation plug, which is connected by a male contact and a female contact on the outer shell and is fixed to the outside of the vacuum chamber by bolts.

4. The large area beam current monitoring device of claim 1, wherein: 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 a host computer. The low-resistance resistor is connected in series with a tungsten filament. The voltage measuring device is used to measure the voltage signal from the low-resistance resistor. The preamplifier is used to amplify the voltage signal from the voltage measuring device. The ADC converts the amplified voltage signal into a digital signal. The MCU processes the digital signal converted by the ADC, performs calculations, and stores the data. The host computer is used for real-time monitoring and data acquisition.

5. A method of monitoring beam current straggling over a large area, characterized by: Includes the following steps: S1: Two insulating fixing blocks are set on each of the left and right sides of the neutralizer beam inlet. The insulating fixing blocks are symmetrically distributed on the upper and lower sides of the neutralizer inlet. The two symmetrical insulating fixing blocks are called a group, and there are three groups on each side of the neutralizer. S2: Based on the installation of a tension spring on each of the three sets of insulating fixing blocks, the tension of the tungsten wire installed on the tension spring can be adjusted; S3: Tungsten wires are installed on the tension spring. A low-resistance resistor is connected in series with each group of tungsten wires. The current is calculated based on the voltage drop generated by the current passing through the resistor. The three groups of tungsten wires are distributed at a certain distance. The intensity of the neutral beam stray current is obtained based on the tungsten wires. S4: The end of the tungsten wire is connected to a signal acquisition system, which is connected to an aviation plug. The aviation plug is fixed outside the beamline vacuum chamber and transmits the neutral stray beam current acquired by the tungsten wire to the beamline vacuum chamber. S5: The signal acquisition system includes a low-resistance resistor, a preamplifier, a voltage measurement device, an analog-to-digital converter (ADC), a microcontroller (MCU), and a host computer. The low-resistance resistor converts the current signal into a voltage signal for subsequent processing. The preamplifier amplifies the weak voltage signal output by the low-resistance resistor, increasing the amplitude of the voltage signal, and also filters and denoises the signal. The voltage measurement device measures the voltage signal from the low-resistance resistor. The ADC converts the analog signal into a digital signal for computer processing. The MCU is responsible for data acquisition, processing, and control. The host computer is responsible for data display and control. The neutral beam stray current monitoring obtains the required current through resistance sampling, thereby achieving beam stray current monitoring. The resistance sampling method specifically involves using a low-resistance resistor with a known resistance value and connecting it in series in the circuit. The low resistance value of the resistor has a small effect on the current flow in the circuit. The voltage drop across a low-resistance resistor is measured using a voltage measuring device and denoted as V. drop ; Based on the measured voltage drop and the known resistance value of the low-resistance resistor, the current flowing through the resistor is calculated using Ohm's law. The formula is as follows: ， Where I is the current flowing through the low-resistance resistor, and V drop It is the voltage drop across the low-resistance resistor, R shunt It is the resistance value of a low-resistance resistor.

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