B-dot probe for petal accelerator and detection method adopting probe

Abstract

The invention provides a B-dot probe for a petal accelerator and a detection method using the probe, and the probe is characterized in that a cavity is in a hollow cylindrical shape, and a protruding annular space is arranged in the middle of the cavity; the angular induction coils are arranged in the annular space, the multiple angular induction coils are evenly arranged along the circumference of the annular space, and the plane where the angular induction coils are located is parallel to the axis of the cavity; the coaxial connectors are arranged on the peripheral wall of the annular space and correspond to the angular induction coils one to one, the coaxial connectors penetrate through the cavity to be connected with the angular induction coils, and inner and outer conductors of the coaxial connectors are electrically connected with the two ends of the angular induction coils respectively. The probe provided by the invention is based on an inductive coupling principle, is good in low-frequency response, can obtain a relatively strong signal for an electron beam of the petal-shaped accelerator, can monitor the flow intensity and track of the electron beam in the petal-shaped accelerator back and forth in a coaxial resonant cavity each time in real time, and assists a machine in debugging and running; the probe is compact in structure and can be installed at any inlet and outlet of the coaxial resonant cavity.

Description

Technical Field

[0001] This invention relates to the field of detection, specifically to a B-dot probe for a petal accelerator and a detection method using the probe. Background Technology

[0002] A petal-shaped accelerator is an electron accelerator that uses the radial electric field of a coaxial resonant cavity to repeatedly accelerate a high-quality electron beam. The electron beam, drawn from the electron gun, passes radially through the coaxial resonant cavity at the center of the petal-shaped accelerator multiple times. Each time it passes through the coaxial resonant cavity, the electron beam is accelerated once, and this cycle is repeated several times before it is drawn out.

[0003] Monitoring the position and current intensity of the electron beam after each pass through the coaxial resonant cavity (or before passing through the coaxial resonant cavity) is beneficial for controlling the electron beam trajectory, assessing beam loss, and implementing interlocking protection controls. Due to the compact structure of petal-shaped accelerators, monitoring the lateral position and current intensity of the beam at the inlet (outlet) of the coaxial resonant cavity requires the use of smaller probes; furthermore, higher-energy petal-shaped accelerators require the electron beam to travel back and forth through the coaxial resonant cavity more times, further reducing the space available for installing the probe. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a probe that can be installed at the inlet (outlet) of the coaxial resonant cavity of a petal-shaped accelerator. The output signal of this probe can be used to monitor the lateral position and flux intensity of the electron beam as it passes through, thereby assisting in the debugging and operation of the accelerator.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] In a first aspect, the present invention provides a B-dot probe for a petal accelerator, comprising:

[0007] The cavity is hollow and cylindrical, with a raised annular space in the middle.

[0008] Angle induction coils are set in an annular space. Multiple angle induction coils are evenly arranged along the circumference of the annular space, and the plane where the angle induction coils are located is parallel to the axis of the cavity.

[0009] The coaxial connector is located on the outer periphery of the annular space, with the same number as the angular induction coils and corresponding one-to-one with each angular induction coil. The coaxial connector passes through the cavity and connects to the angular induction coils. The inner and outer conductors of the coaxial connector are electrically connected to the two ends of the angular induction coils, respectively.

[0010] Furthermore, the angular induction coil is a non-closed coil, with one end connected to the inner conductor of the coaxial connector and the other end connected to the outer conductor of the coaxial connector.

[0011] Furthermore, the angular induction coil includes an extension conductor, one end of which is connected to the inner conductor of the coaxial connector, and the other end is connected to the inner wall of the cavity. The outer conductor of the coaxial connector is welded to the outer wall of the cavity. The connection point between the cavity and the outer conductor extends to the part of the cavity where it connects with the extension conductor. Together with the extension conductor, the angular induction coil is formed.

[0012] Furthermore, the cavity remains sealed at the point where the coaxial connector passes through.

[0013] Furthermore, the number of angular induction coils is four.

[0014] Secondly, a probe as described in the first aspect is set between the entrance of the coaxial resonant cavity and the deflecting magnet. In the probe, one end of the cavity is connected to the coaxial resonant cavity through a vacuum flange, and the other end is connected to the vacuum pipe of the deflecting magnet through a vacuum flange. The coaxial connector is connected to an external electronic system through a circuit.

[0015] Furthermore, a probe is placed between the outlet of the coaxial resonant cavity and the deflecting magnet.

[0016] Furthermore, a probe is installed at the main outlet of the coaxial resonant cavity.

[0017] Based on the above technical solution, the following technical effects can be achieved:

[0018] The probe provided by this invention is based on the principle of inductive coupling. The probe has good low-frequency response and can obtain a strong signal from the electron beam of the petal-shaped accelerator. It can monitor the current intensity and trajectory of the electron beam in the petal accelerator each round trip to the coaxial resonant cavity in real time, and assist in the debugging and operation of the machine. The probe of this invention has a compact structure and can be installed at any entrance and exit of the coaxial resonant cavity. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the first embodiment of the present invention;

[0021] Figure 2 for Figure 1 A schematic diagram of the principle after longitudinal sectioning at the position of the electron beam;

[0022] Figure 3 This is a schematic diagram of the structure of the second embodiment of the present invention;

[0023] Figure 4 For the installation and arrangement of the probe Figure 1 ;

[0024] Figure 5 For the installation and arrangement of the probe Figure 2 . Detailed Implementation

[0025] It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] In a first aspect, the present invention provides a B-dot probe for a petal accelerator (a B-dot probe is a sensor designed based on the principle of electromagnetic induction, mainly used to measure rapidly changing magnetic fields (such as dB / dt) or differential current signals), such as Figure 1-3 ,include:

[0028] The cavity 100 is a hollow cylinder with a raised annular space 101 in the middle.

[0029] An angular induction coil 200 is disposed in the annular space 101. Multiple angular induction coils 200 are evenly arranged along the circumference of the annular space 101, and the plane where the angular induction coils 200 are located is parallel to the axis of the cavity 100.

[0030] The coaxial connector 300 is located on the outer peripheral wall of the annular space 101. The number of coaxial connectors 300 is the same as that of the angular induction coils 200, and they correspond one-to-one with the angular induction coils 200. The coaxial connector 300 passes through the cavity 100 and connects to the angular induction coils 200. The inner and outer conductors of the coaxial connector 300 are electrically connected to the two ends of the angular induction coils 200, respectively.

[0031] In one embodiment, the first type: such as Figure 1 and 2 The angular induction coil 200 is a non-closed coil, with one end connected to the inner conductor 302 of the coaxial connector 300 and the other end connected to the outer conductor 301 of the coaxial connector 300. This method makes the placement of the coil within the cavity 100 more complicated, requiring consistency in the shape and installation angle of multiple angular induction coils 200, which makes operation much more difficult.

[0032] Figure 1 and Figure 2This is a demonstration diagram of the first embodiment, not a specific structural diagram. Therefore, the structure in the diagram is simplified so as to express the principle. The structure of this invention mainly adopts the second type.

[0033] The second type: such as Figure 3 The angular induction coil 200 includes an extension conductor 201. One end of the extension conductor 201 is connected to the inner conductor 302 of the coaxial connector 300, and the other end is connected to the inner wall of the cavity 100. The outer conductor 301 of the coaxial connector 300 is soldered to the outer wall of the cavity 100. The connection point between the cavity 100 and the outer conductor 301 extends to the portion of the cavity 100 connected to the extension conductor 201. Together with the extension conductor 201, the angular induction coil 200 is formed. In this way, the cavity 100 (all cavities are made of conductive metal) is used to assemble the coil, as shown below. Figure 3 The extension conductor 201 is L-shaped, forming a square coil, which makes installation and use more convenient. The L-shaped extension conductor 201 is designed to maintain impedance continuity.

[0034] The actual method adopted in this invention is the second one. Its coaxial connector 300 adopts a through-wall connector (which is an existing device and will not be described in detail). The outer conductor 301 is welded and fixed to the outer wall of the cavity 100. The inner conductor 302 passes through the ceramic seal 303 and enters the cavity 100. It is electrically connected to the inner wall of the cavity 100 through an extension conductor 201. The extension conductor 201 and the cavity 100 form an angular induction coil 200. The plane of the angular induction coil 200 is parallel to the axis of the cavity 100. The extension conductor 201 is L-shaped and electrically connected to the inner wall of the cavity 100. The connection point between the outer conductor 301 and the outer wall of the cavity 100 is well designed, which can ensure the consistency of multiple angular induction coils 200.

[0035] The outer conductor 301 is welded to the outer wall of the B-dot to achieve a good electrical connection. The ceramic seal 303 is a vacuum seal. The inner conductor 302 is connected to the stainless steel extension conductor 201 by threads. After the extension conductor 201 turns at a right angle, it extends axially to one side end face of the cavity 100 and forms a good electrical connection with the end face of the cavity 100, forming a current path of inner conductor → extension body → outer wall of cavity → outer conductor.

[0036] The number of angular induction coils 200 is four. This forms four single-turn angular induction coils evenly distributed at a 90° angle inside the B-dot monitoring probe, connected to the inner and outer conductors. During probe installation, the four angular induction coils 200 can be positioned in the four cardinal directions (up, down, left, right), or they can be installed at a specific angle. The difference lies in the fact that the angle of probe rotation needs to be taken into account when calculating the lateral position of the electron beam 700 during subsequent data processing.

[0037] Furthermore, the angular induction coil 200 is located outside the radius of the upstream and downstream vacuum pipes, so it will not affect the transmission of the electron beam. The angular induction coil 200 is completely located within the annular space 101, and the angular induction coil 200 is not exposed in the pipe formed in front of and behind the cavity 100.

[0038] Secondly, petal-shaped accelerators are existing technologies, such as CN202310881333.9, which describes an inner conductor truncated petal accelerator that includes a coaxial resonant cavity 400 and a deflecting magnet 500.

[0039] A probe 600, as described in the first aspect, is positioned between the inlet of the coaxial resonant cavity 400 and the deflecting magnet 500. In the probe 600, one end of the cavity 100 is connected to the coaxial resonant cavity 400 via a vacuum flange, and the other end is connected to the vacuum channel of the deflecting magnet 500 via a vacuum flange. A coaxial connector 300 is connected via wiring to an external BPM electronics system or oscilloscope, such as... Figure 4 The probe 600 is located only between the inlet of the coaxial resonant cavity 400 and the deflecting magnet 500. A probe 600 can also be installed between the outlet of the coaxial resonant cavity 400 and the deflecting magnet 500, using the same method: connecting to the outlet of the coaxial resonant cavity 400 and the vacuum pipe port of the deflecting magnet 500 via vacuum flanges. Alternatively, a probe 600 can be installed at the main outlet of the coaxial resonant cavity 400, also connected via a vacuum flange. Figure 5 There is a probe 600 between the inlet / outlet of the coaxial resonant cavity 400 and the deflection magnet 500, and a probe 600 is set at the main outlet of the coaxial resonant cavity 400, which can comprehensively monitor the behavior of the electron beam.

Claims

1. A B-dot probe for a petal accelerator, characterized in that: include: The cavity is hollow and cylindrical, with a raised annular space in the middle. Angle induction coils are set in an annular space. Multiple angle induction coils are evenly arranged along the circumference of the annular space, and the plane where the angle induction coils are located is parallel to the axis of the cavity. The coaxial connector is located on the outer periphery of the annular space, with the same number as the angular induction coils and corresponding one-to-one with each angular induction coil. The coaxial connector passes through the cavity and connects to the angular induction coils. The inner and outer conductors of the coaxial connector are electrically connected to the two ends of the angular induction coils, respectively.

2. The B-dot probe for a petal accelerator according to claim 1, wherein the angular induction coil is a non-closed coil, one end of which is connected to the inner conductor of the coaxial connector and the other end of which is connected to the outer conductor of the coaxial connector.

3. A B-dot probe for a petal accelerator according to claim 1, wherein the angular induction coil includes an extension conductor, one end of which is connected to the inner conductor of a coaxial connector, and the other end is connected to the inner wall of a cavity. The outer conductor of the coaxial connector is welded to the outer wall of the cavity. The connection point between the cavity and the outer conductor extends to the portion of the cavity connected to the extension conductor. Together with the extension conductor, the angular induction coil is formed.

4. A B-dot probe for a petal accelerator according to claim 1, wherein the cavity remains sealed at the through-hole of the coaxial connector.

5. A B-dot probe for a petal accelerator according to claim 1, characterized in that: The number of angular induction coils is four.

6. A method for detecting petal accelerators, the petal accelerator comprising a coaxial resonant cavity and a plurality of deflecting magnets, characterized in that: A probe as described in any one of claims 1-5 is provided between the inlet of the coaxial resonant cavity and the deflecting magnet. In the probe, one end of the cavity is connected to the coaxial resonant cavity through a vacuum flange, and the other end is connected to the vacuum pipe of the deflecting magnet through a vacuum flange. The coaxial connector is connected to an external electronic system through a circuit.

7. The method for detecting petals in a petal accelerator according to claim 6, characterized in that: A probe is placed between the outlet of the coaxial resonant cavity and the deflecting magnet.

8. A method for detecting petals in a petal accelerator according to claim 6 or 7, characterized in that: A probe is installed at the main outlet of the coaxial resonant cavity.

Images