Reflection type microfocus X-ray tube and control method thereof

Abstract

The invention relates to the technical field of micro-focus X-ray tubes, and provides a reflective micro-focus X-ray tube and a control method thereof.The reflective micro-focus X-ray tube comprises a cathode unit, an electron beam focusing unit and an electron beam reflecting unit which are sequentially connected; the electron beam reflection unit comprises a shielding window, a target window, a restraining window, a cooling part and a conical target. The input end of the restraining window is arranged in the focusing coil shell and the electron beam outlet of the focusing unit, and the output end of the restraining window extends into the upper part of the cooling component; the conical target is arranged in the axial direction of the cooling component, and the top of the conical target is provided with a conical reflecting surface; an inclined shielding window is arranged above the conical target and the cooling part; a ray outlet is formed in the shielding window; and the shielding window is provided with a target window at the front end of the ray outlet. According to the invention, the X-ray conversion efficiency and the ray precision can be ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of micro-focus ray tubes, and in particular to a reflective micro-focus X-ray tube and a control method thereof. Background Art

[0002] With the development of non-destructive testing, the demand for high-magnification and high-quality images is increasing. Microfocus X-ray tubes are mainly used for high-precision and fine defect detection, and their application areas cover aviation, aerospace, electronic industry, composite materials, plastics, and light metals.

[0003] Micro-focus X-ray tubes are mainly transmission-type micro-focus X-ray tubes. At present, in transmission-type micro-focus X-ray tubes, the target unit is connected to the target and the target placement seat through the target locking nut. The target adopts a transmission target, which causes the electron beam to bombard the target surface directly, and the transmission target is generally very thin. Therefore, there are technical problems such as poor heat dissipation and unfocused beams.

[0004] In addition, the transmission type micro-focus X-ray tube uses relatively low power and cannot meet the requirements of high power and long-term use. Summary of the invention

[0005] The present invention mainly solves the technical problems of poor heat dissipation, unfocused X-ray beam, low power and the like in the prior art, and proposes a reflective micro-focus X-ray tube and a control method thereof to ensure the conversion efficiency and ray accuracy of X-rays.

[0006] The present invention provides a reflective micro-focus X-ray tube, comprising: a cathode unit, an electron beam focusing unit and an electron beam reflecting unit connected in sequence;

[0007] A molecular pump is installed on the cathode unit; a vacuum gauge is installed on the molecular pump;

[0008] The electron beam focusing unit comprises: a focusing end surface, a central axis, a focusing coil shell and an anode shell which are fixedly connected in sequence;

[0009] The focusing end surface is fixedly connected to the cathode unit; the focusing end surface has a focusing unit electron beam entrance;

[0010] A deflection coil group is arranged on the central axis, and the central axis has a first electron beam channel;

[0011] A focusing coil group is arranged on the focusing coil housing, and the focusing coil housing has a second electron beam channel;

[0012] The anode housing is formed with a focusing unit electron beam outlet;

[0013] The focusing unit electron beam inlet, the first electron beam channel, the second electron beam channel and the focusing unit electron beam outlet are on the same straight line;

[0014] The electron beam reflection unit comprises: a shielding window, a target window, a restraining window, a cooling component and a conical target;

[0015] The input end of the restraining window is placed in the focusing coil housing and the electron beam outlet of the focusing unit, and the output end of the restraining window extends above the cooling component;

[0016] The conical target is placed in the axial direction of the cooling component, and the top of the conical target has a conical reflecting surface; an obliquely arranged shielding window is provided above the conical target and the cooling component;

[0017] A ray outlet is reserved on the shielding window; a target window is installed at the front end of the ray outlet of the shielding window.

[0018] Preferably, the electron beam focusing unit and the cathode unit are fixed via a hinge joint.

[0019] Preferably, the cathode unit comprises: a cathode housing and a cathode generating device arranged in the cathode housing;

[0020] The cathode housing is provided with a molecular pump via a connecting component.

[0021] Preferably, the cathode generating device comprises: a grid cap, a filament assembly, a grid fixing seat and a high-voltage sleeve;

[0022] A grid fixing seat is fixedly arranged on the top of the high-voltage sleeve;

[0023] A filament assembly is arranged on the grid fixing seat; a grid cap is detachably arranged on the grid fixing seat; the grid cap wraps the filament assembly inside;

[0024] The filament assembly comprises: a filament assembly housing, a filament, a ceramic base and two pole needles;

[0025] The bottom of the pole needle is connected to the filament pole of the high-voltage sleeve; the pole needle is fixedly connected to the ceramic base, and the top of the pole needle extends out of the ceramic base; the tops of the two pole needles are respectively connected to the two ends of the filament;

[0026] A filament assembly housing is arranged on the ceramic seat; the filament assembly housing covers the filament, the ceramic seat and the pole needle;

[0027] The centers of the filament assembly housing and the grid cap are respectively provided with emission holes.

[0028] Preferably, a high-pressure sleeve flange is fixedly arranged at the bottom of the high-pressure sleeve;

[0029] The grid fixing seat has a plurality of spring retaining mechanisms evenly distributed in the circumferential direction; the grid cap is detachably arranged on the grid fixing seat through the spring retaining mechanisms;

[0030] The filament is directly welded and fixed on the pole needle; the filament is obtuse-angled; the shell of the filament assembly is fixed to the ceramic seat through a top screw;

[0031] The grid fixing seat is connected to the common contact of the high-voltage sleeve; the grid fixing seat is in contact with the grid cap and the outer shell of the filament assembly, and the grid cap is in contact with the outer shell of the filament assembly.

[0032] Preferably, the cathode generating device of the cathode unit is electrically connected to the high voltage unit.

[0033] Preferably, the deflection coil group and the focusing coil group are electrically connected to a DC voltage-stabilized constant current source.

[0034] Preferably, the molecular pump, vacuum gauge, electron beam reflection unit and high voltage unit are electrically connected to a data acquisition unit respectively; and the data acquisition unit is electrically connected to a host computer.

[0035] Correspondingly, the present invention further provides a control method for a reflective microfocus X-ray tube according to any embodiment of the present invention, comprising the following process:

[0036] The data acquisition unit collects the turbine speed of the molecular pump, the vacuum degree of the vacuum gauge, the target current of the electron beam reflection unit, and the actual tube voltage and actual tube current of the high-voltage unit;

[0037] The data acquisition unit feeds back the turbine speed of the molecular pump and the vacuum degree collected by the vacuum gauge to the host computer; the host computer determines whether the turbine speed reaches the turbine speed threshold and whether the vacuum degree reaches the vacuum degree threshold;

[0038] The data acquisition unit feeds back the target current of the electron beam reflection unit to the host computer; the host computer controls the DC voltage-stabilized constant current source to output a voltage-stabilized current according to the target current of the electron beam reflection unit, so that the deflection coil group and the focusing coil group generate a stable electric field force to control the electron beam;

[0039] The data acquisition unit feeds back to the host computer according to the actual tube voltage and actual tube current of the high-voltage unit; the host computer adjusts the actual tube voltage of the high-voltage unit to the tube voltage threshold of the high-voltage unit, and adjusts the actual tube current of the high-voltage unit to the tube current threshold of the high-voltage unit.

[0040] A reflective micro-focus X-ray tube and a control method thereof provided by the present invention have the following advantages compared with the prior art:

[0041] 1. The electron beam reflection mechanism, anode / cathode assembly and sleeve are connected in series to ensure the conversion efficiency and accuracy of X-rays. The high-power use time of the X-ray tube is guaranteed, overcoming the disadvantage that the transmission micro-focus X-ray tube cannot be used for a long time at high power.

[0042] 2. The target part adopts an electron beam reflection unit, and there is an inclined shielding window above the conical target and the cooling component; a ray outlet is left on the shielding window; the shielding window is installed with a target window at the front end of the ray outlet, and adopts a reflective type; the conical target is placed in the cooling component and cooled so as to effectively reflect the electron beam. The present invention can emit high voltage and high current, and can change the direction of the electron beam.

[0043] 3. The cathode generating device of the present invention decomposes the structure into multiple components for assembly. If there is a problem with the filament, it can be replaced. A retaining spring mechanism and a top screw are provided to make the replacement of the filament more convenient. A high-voltage sleeve flange is installed at the rear end of the high-voltage sleeve, which is connected to the cathode housing through the high-voltage sleeve flange. The high-voltage sleeve flange can drive the high-voltage sleeve to perform fine-tuning, which is convenient for adjustment and reduces the requirements for assembly accuracy. The cathode generating device introduces a grid, which can better control the tube current and at the same time play a primary focusing role of the electron beam. The pole needle and the ceramic seat are connected and fixed by ceramic metallization, which solves the connection problem between the ceramic and the electrode needle, and avoids the influence of third-party media on the quality and the influence on the vacuum in the open microfocus ray tube. The direct welding of the filament and the pole needle avoids the influence of transition metals on the performance of the filament.

[0044] 4. The molecular pump, vacuum gauge, electron beam reflection unit and high voltage unit are electrically connected to the data acquisition unit respectively, and the data acquisition unit is electrically connected to the host computer. The data acquisition unit collects feedback parameters of each part and uploads them to the host computer in real time. The data acquisition unit has strong anti-interference ability, and accurately and efficiently collects and feeds back turbine speed, vacuum degree, target current, tube voltage and tube current data to the host computer. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a schematic diagram of the arrangement of the reflective micro-focus X-ray tube provided by the present invention;

[0046] Figure 2 It is a schematic structural diagram of a reflective micro-focus X-ray tube provided by the present invention;

[0047] Figure 3 is an axial cross-sectional view of a reflective micro-focus X-ray tube provided by the present invention;

[0048] Figure 4 is an axial cross-sectional view of the cathode unit provided by the present invention;

[0049] Figure 5is an axial cross-sectional view of the cathode generating device provided by the present invention;

[0050] Figure 6 is an axial cross-sectional view of the electron beam focusing unit provided by the present invention;

[0051] Figure 7 is an axial cross-sectional view of the electron beam reflection unit provided by the present invention;

[0052] Figure 8 It is a schematic diagram of the emission of the electron beam reflection unit provided by the present invention.

[0053] In the figure: 1, electron beam reflection unit; 2, electron beam focusing unit; 3, hinge joint; 4, cathode unit; 5, molecular pump; 6, vacuum gauge; 7, DC constant current source; 8, detection unit; 9, data acquisition unit; 10, high voltage unit; 11, host computer; 101, shielding window; 102, target window; 103, restraint window; 104, cooling component; 105, conical target; 106, joint; 201, focusing end face; 202, central axis; 203, deflection coil group; 204, focusing coil outer Shell; 205, focusing coil group; 206, anode shell; 207, deflection coil group shell; 208, focusing unit electron beam inlet; 209, focusing unit electron beam outlet; 210, connecting shell; 401, grid cap; 402, filament assembly shell; 403, filament; 404, ceramic seat; 405, pole needle; 406, top wire; 407, spring mechanism; 408, grid fixing seat; 409, high-voltage sleeve; 410, high-voltage sleeve flange; 411, cathode shell; 412, connecting parts. DETAILED DESCRIPTION

[0054] In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for the convenience of description, only the parts related to the present invention are shown in the accompanying drawings, rather than all the contents.

[0055] like Figure 1-3 As shown, the reflective micro-focus X-ray tube provided by the embodiment of the present invention comprises: a cathode unit 4, an electron beam focusing unit 2 and an electron beam reflecting unit 1 which are connected in sequence.

[0056] The cathode unit 4 is provided with a molecular pump 5; specifically, the cathode housing 411 of the cathode unit 4 is provided with the molecular pump 5 via a connecting component 412. The molecular pump 5 is provided with a vacuum gauge 6. The molecular pump 5 provides vacuum to the cathode unit 4, and the vacuum gauge 6 can detect the vacuum degree in the cathode unit 4 in real time and feed it back to the host computer 11.

[0057] like Figure 4 As shown, the cathode unit 4 includes: a cathode shell 411 and a cathode generating device arranged in the cathode shell 411.

[0058] like Figure 5 As shown, the cathode generating device comprises: a grid cap 401, a filament assembly, a grid fixing seat 408 and a high-voltage sleeve 409. The high-voltage sleeve 409 is an insulating component connected to high voltage, which can not only ensure the stability and safety of the circuit connection, but also effectively prevent current leakage and electrical faults in the circuit. The high-voltage sleeve 409 has two filament poles and a common contact.

[0059] The grid fixing seat 408 is fixedly arranged on the top of the high-voltage sleeve 409; the high-voltage sleeve flange 410 is fixedly arranged on the bottom of the high-voltage sleeve 409. The cathode generating device is installed in the cathode housing 411 through the high-voltage sleeve flange 410, and the high-voltage sleeve flange 410 is installed through the top screw matched with the flange. By adjusting the top screw, the position of the high-voltage sleeve 409 in the cathode housing 411 can be finely adjusted.

[0060] The grid fixing base 408 is provided with a filament assembly; the grid fixing base 408 is detachably provided with a grid cap 401; the grid cap 401 wraps the filament assembly therein.

[0061] The filament assembly includes: a filament assembly housing 402, a filament 403, a ceramic base 404 and two pole needles 405; the bottom of the pole needle 405 is connected to the filament pole of the high-voltage sleeve 409; the pole needle 405 is fixedly connected to the ceramic base 404, and the top of the pole needle 405 extends out of the ceramic base 404; the tops of the two pole needles 405 are respectively connected to the two ends of the filament 403; the filament 403 is in an obtuse angle. The filament 403 is directly welded and fixed on the pole needle 405. Direct welding is adopted to subtract transition metals and eliminate the influence of transition metals on its stability.

[0062] A filament assembly housing 402 is disposed on the ceramic seat 404 ; the filament assembly housing 402 covers the filament 403 , the ceramic seat 404 and the pole needle 405 ; and emission holes are respectively reserved in the centers of the filament assembly housing 402 and the grid cap 401 .

[0063] The filament assembly housing 402 is fixed to the ceramic base 404 through a top screw 406, so that the filament 403, the ceramic base 404, and the pole needle 405 are fixed in the filament assembly housing 402. By adjusting and removing the top screw 406, the replacement and removal of the filament assembly are facilitated.

[0064] The grid fixing seat 408 has multiple spring mechanisms 407 evenly distributed in the circumferential direction; the grid cap 401 is detachably arranged on the grid fixing seat 408 through the spring mechanisms 407. Considering the frequent replacement of the filament assembly, the spring mechanisms 407 are arranged, and the grid cap 401 can be opened by pressing the spring mechanisms 407, making it more convenient to replace the filament.

[0065] The pole needle 405 is connected and fixed to the ceramic base 404 by ceramic metallization. By selecting materials and degassing the ceramic base 404, the gas content in the ceramic base 404 is reduced as much as possible, and its influence on the ultimate vacuum of the open micro-focus X-ray tube is reduced. By the ceramic metallization process, the connection medium is changed, its high temperature resistance is improved, and its original defects are removed.

[0066] The grid fixing seat 408 is connected to the common contact of the high-voltage sleeve 409; the grid fixing seat 408 is in contact with the grid cap 401 and the filament assembly housing 402, and the grid cap 401 is in contact with the filament assembly housing 402. The grid cap 401, the filament assembly housing 402 and the grid fixing seat 408 are all made of metal. Therefore, the grid cap 401, the filament assembly housing 402 and the grid fixing seat 408 can be electrically connected, and the grid cap 401 can focus the electron beam by controlling the tube current, thereby realizing the grid function.

[0067] During assembly, the grid fixing seat 408 is fixed on the high-voltage sleeve 409, and then the filament assembly housing 402, the filament 403, the ceramic seat 404, the pole needle 405, and the top screw 406 are fixed on the high-voltage sleeve 409, and then the grid cap 401 is fixed by the spring mechanism 407. The grid cap 401 wraps the filament assembly housing 402, the filament 403, the ceramic seat 404, the pole needle 405, and the top screw 406. When in use, the entire cathode generating device is connected and fixed to the cathode housing 411 through the high-voltage sleeve flange 410.

[0068] The cathode generating device connects the high voltage to the filament 403 through the high voltage sleeve 409, and the electron beam is emitted by the filament 403. The focusing of the electron beam is controlled by the grid cap 401, so that the focused electron beam can smoothly enter the anode part of the open micro-focus ray tube.

[0069] The cathode generating device of the cathode unit 4 is connected to the high voltage unit 10. The high voltage unit 10 generates an acceleration voltage and a filament current which are transmitted to the grid cap 401 and the filament 403 through a high voltage cable. After the voltage is applied, the cathode generating device generates an electron beam.

[0070] The electron beam focusing unit 2 and the cathode unit 4 are fixed by a hinge joint 3. The hinge joint 03 facilitates opening the ray tube during maintenance.

[0071] like Figure 6 As shown, the electron beam focusing unit 2 comprises: a focusing end face 201, a central axis 202, a focusing coil housing 204 and an anode housing 206 which are fixedly connected in sequence. A connecting housing 210 is arranged between the focusing end face 201 and the focusing coil housing 204 to ensure the sealing of the electron beam focusing unit 2.

[0072] The focusing end surface 201 is fixedly connected to the cathode unit 4; the focusing end surface 201 has a focusing unit electron beam entrance 208; a deflection coil group 203 is arranged on the central axis 202, and the central axis 202 has a first electron beam channel; a deflection coil group housing 207 is covered on the deflection coil group 203. A focusing coil group 205 is arranged on the focusing coil housing 204, and the focusing coil housing 204 has a second electron beam channel; the anode housing structure 206 has a focusing unit electron beam exit 209; the focusing unit electron beam entrance 208, the first electron beam channel, the second electron beam channel and the focusing unit electron beam exit 209 are on the same straight line.

[0073] The electron beam generated by the cathode unit 4 passes through the focusing unit electron beam inlet 208, the first electron beam channel, and the second electron beam channel in sequence, and hits the restraining window 103 of the electron beam reflecting unit 1. When the electron beam passes through the cathode unit 4, by adjusting the current of the deflection coil group 203 and the focusing coil group 205, the deflection coil group 203 can control the direction of the electron beam, and the focusing coil group 205 can control the thickness of the electron beam.

[0074] like Figure 7 As shown, the electron beam reflection unit 1 comprises: a shielding window 101, a target window 102, a restraining window 103, a cooling component 104 and a conical target 105; the input end of the restraining window 103 is placed in the focusing coil housing 204 and the focusing unit electron beam outlet 209, and the output end of the restraining window 103 extends above the cooling component 104; the conical target 105 is placed in the axial direction of the cooling component 104, and the top of the conical target 105 has a conical reflection surface; the conical target 105 and the cooling component 104 are provided with an inclined shielding window 101; the shielding window 101 is provided with a ray outlet 107; the shielding window 101 is provided with a target window 102 at the front end of the ray outlet. In addition, a joint 106 is provided at the bottom end of the conical target 105 for connecting a cooling water pump to realize cooling of the conical target 105. The cooling water pump is electrically connected to the detection unit 8, and the detection unit 8 is used to detect the cooling temperature and flow rate.

[0075] In the electron beam reflecting unit 1, as Figure 8As shown, the electron beam passes through the restraining window 103 and hits the conical reflective surface at the top of the conical target 105. The conical reflective surface changes the direction of the electron beam and hits the electron beam on the target window 102, generating X-rays that pass through the target window 102 and are emitted from the ray outlet 107. The conical reflective surface is set on the top of the conical target 105 to change the direction of the electron beam. The conical target 105 is placed in the cooling component 104 to cool it so that it can effectively reflect the electron beam.

[0076] The deflection coil group 203 and the focusing coil group 205 are electrically connected to the DC voltage-stabilized constant current source 7, and the DC voltage-stabilized constant current source 7 has excellent performances such as ripple, output stability and response speed. The grid cap 401 is connected to the high-voltage unit 10; the focusing end face 201, the central axis 202, the focusing coil housing 204, the anode housing 206 and the deflection coil group 203 together constitute a ray source lens structure. The cathode generating device of the cathode unit 4 is electrically connected to the high-voltage unit 10. The high-voltage unit 10 used in the present invention applies high-frequency inverter power supply technology to the micro-focus system, making the output ripple smaller and improving the imaging quality. The transformer adopts a segmented winding structure to reduce the influence of distributed capacitance on the stable operation of the system.

[0077] The working process of the present invention is as follows: the cathode generating device of the cathode unit 4 is connected to the high voltage unit 10, the upper computer 11 controls the high voltage unit 10 to pressurize the cathode generating device, after the voltage is applied, the cathode generating device generates an electron beam, the electron beam is emitted from the cathode unit 4 to the electron beam reflecting mechanism 1 via the electron beam focusing unit 2, the electron beam hits the target window 102 of the electron beam reflecting mechanism 1, generates X-rays and is emitted from the ray outlet 107. After the X-rays are generated, the cone target 105 feeds back the real-time target current data to the data acquisition unit 9.

[0078] The molecular pump 5, vacuum gauge 6, electron beam reflection unit 1 and high voltage unit 10 are electrically connected to the data acquisition unit 9 respectively, and the data acquisition unit 9 is electrically connected to the host computer 11. The data acquisition unit 9 collects the feedback parameters of each part and uploads them to the host computer 11 in real time. The data acquisition unit 9 has strong anti-interference ability and accurately and efficiently collects and feeds back the turbine speed, vacuum degree, target current, tube voltage and tube current data to the host computer 11. The specific control process is as follows:

[0079] The data acquisition unit 9 acquires the turbine speed of the molecular pump 5, the vacuum degree of the vacuum gauge 6, the target current of the electron beam reflection unit 1, and the actual tube voltage and actual tube current of the high voltage unit 10;

[0080] The data acquisition unit 9 feeds back the turbine speed of the molecular pump 5 and the vacuum degree collected by the vacuum gauge 6 to the host computer 11; the host computer 11 determines whether the turbine speed reaches the turbine speed threshold and whether the vacuum degree reaches the vacuum degree threshold to determine whether the ray can be turned on. The molecular pump 5 and the vacuum gauge 6 of the present invention are controlled by the host computer 11 to ensure that the vacuum degree inside the ray tube reaches the ray generation condition, and ensure that the filament generates a stable electron beam and the ray tube generates stable rays. This measure can effectively extend the life of the filament and improve the stability of the ray source.

[0081] The data acquisition unit 9 feeds back the target current of the electron beam reflecting unit 1 to the host computer 11; the host computer 11 controls the DC voltage-stabilized constant current source 7 to output a regulated current according to the target current of the electron beam reflecting unit 1, so that the deflection coil group 203 and the focusing coil group 205 generate a stable electric field force to control the electron beam, so as to automatically control the ray tube to generate rays with the best focus size, so that the ray tube achieves the best imaging effect.

[0082] The data acquisition unit 9 feeds back to the host computer 11 according to the actual tube voltage and actual tube current of the high-voltage unit 10; the host computer 11 adjusts the actual tube voltage of the high-voltage unit 10 to the high-voltage unit tube voltage threshold, and adjusts the actual tube current of the high-voltage unit 10 to the high-voltage unit tube current threshold.

[0083] Through the above control of the host computer 11, it is ensured that the radiation is used normally after being turned on, and the radiation source works safely.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that modifying the technical solutions described in the aforementioned embodiments, or replacing some or all of the technical features therein by equivalents, does not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A reflective micro-focus X-ray tube, characterized in that: include: A cathode unit (4), an electron beam focusing unit (2) and an electron beam reflecting unit (1) connected in sequence; A molecular pump (5) is installed on the cathode unit (4); a vacuum gauge (6) is installed on the molecular pump (5); The electron beam focusing unit (2) comprises: a focusing end surface (201), a central axis (202), a focusing coil housing (204) and an anode housing (206) which are fixedly connected in sequence; The focusing end surface (201) is fixedly connected to the cathode unit (4); the focusing end surface (201) has a focusing unit electron beam inlet (208); A deflection coil group (203) is arranged on the central axis (202), and the central axis (202) has a first electron beam channel; A focusing coil group (205) is arranged on the focusing coil housing (204), and the focusing coil housing (204) has a second electron beam channel; The anode housing (206) has a focusing unit electron beam outlet (209); The focusing unit electron beam inlet (208), the first electron beam channel, the second electron beam channel and the focusing unit electron beam outlet (209) are on the same straight line; The electron beam reflection unit (1) comprises: a shielding window (101), a target window (102), a restraining window (103), a cooling component (104) and a conical target (105); The input end of the restraining window (103) is placed in the focusing coil housing (204) and the focusing unit electron beam outlet (209), and the output end of the restraining window (103) extends above the cooling component (104); The conical target (105) is placed in the axial direction of the cooling component (104), and the top of the conical target (105) has a conical reflection surface; and an obliquely arranged shielding window (101) is provided above the conical target (105) and the cooling component (104); A radiation outlet (107) is left on the shielding window (101); and a target window (102) is installed at the front end of the radiation outlet of the shielding window (101).

2. The reflective microfocus X-ray tube according to claim 1, characterized in that: The electron beam focusing unit (2) and the cathode unit (4) are fixed via a hinge joint (3).

3. The reflective microfocus X-ray tube according to claim 1, characterized in that: The cathode unit (4) comprises: a cathode shell (411) and a cathode generating device arranged in the cathode shell (411); The cathode housing (411) is mounted with a molecular pump (5) via a connecting component (412).

4. The reflective microfocus X-ray tube according to claim 3, characterized in that: The cathode generating device comprises: a grid cap (401), a filament assembly, a grid fixing seat (408) and a high-voltage sleeve (409); A grid fixing seat (408) is fixedly arranged on the top of the high-voltage sleeve (409); A filament assembly is arranged on the grid fixing seat (408); a grid cap (401) is detachably arranged on the grid fixing seat (408); the grid cap (401) wraps the filament assembly inside; The filament assembly comprises: a filament assembly housing (402), a filament (403), a ceramic base (404) and two polar needles (405); The bottom of the pole needle (405) is connected to the filament pole of the high-voltage sleeve (409); the pole needle (405) is fixedly connected to the ceramic base (404), and the top of the pole needle (405) extends out of the ceramic base (404); the tops of the two pole needles (405) are respectively connected to the two ends of the filament (403); A filament assembly housing (402) is disposed on the ceramic seat (404); the filament assembly housing (402) covers the filament (403), the ceramic seat (404) and the pole needle (405); The centers of the filament assembly housing (402) and the grid cap (401) are respectively provided with emission holes.

5. The reflective micro-focus X-ray tube according to claim 4, characterized in that: A high-pressure sleeve flange (410) is fixedly arranged at the bottom of the high-pressure sleeve (409); A plurality of spring retaining mechanisms (407) are evenly distributed in the circumferential direction of the grid fixing seat (408); the grid cap (401) is detachably arranged on the grid fixing seat (408) via the spring retaining mechanism (407); The filament (403) is directly welded and fixed on the pole needle (405); the filament (403) is in an obtuse angle shape; the filament assembly housing (402) is fixed to the ceramic seat (404) via a top screw (406); The grid fixing seat (408) is connected to a common contact of a high-voltage sleeve (409); the grid fixing seat (408) is in contact with a grid cap (401) and a filament assembly housing (402); and the grid cap (401) is in contact with a filament assembly housing (402).

6. The reflective microfocus X-ray tube according to claim 5, characterized in that: The cathode generating device of the cathode unit (4) is electrically connected to the high voltage unit (10).

7. The reflective microfocus X-ray tube according to claim 6, characterized in that: The deflection coil group (203) and the focusing coil group (205) are electrically connected to a DC voltage-stabilized constant current source (7).

8. The reflective microfocus X-ray tube according to claim 7, characterized in that: The molecular pump (5), vacuum gauge (6), electron beam reflection unit (1) and high voltage unit (10) are respectively electrically connected to a data acquisition unit (9); and the data acquisition unit (9) is electrically connected to a host computer (11).

9. A control method for a reflective micro-focus X-ray tube according to claim 8, characterized in that: The process includes: The data acquisition unit (9) acquires the turbine speed of the molecular pump (5), the vacuum degree of the vacuum gauge (6), the target current of the electron beam reflection unit (1), and the actual tube voltage and actual tube current of the high voltage unit (10); The data acquisition unit (9) feeds back the turbine speed of the molecular pump (5) and the vacuum degree collected by the vacuum gauge (6) to the host computer (11); the host computer (11) determines whether the turbine speed reaches a turbine speed threshold and whether the vacuum degree reaches a vacuum degree threshold; The data acquisition unit (9) feeds back the target current of the electron beam reflection unit (1) to the host computer (11); the host computer (11) controls the DC voltage-stabilized constant current source (7) to output a regulated current according to the target current of the electron beam reflection unit (1), so that the deflection coil group (203) and the focusing coil group (205) generate a stable electric field force, thereby controlling the electron beam; The data acquisition unit (9) feeds back to the host computer (11) according to the actual tube voltage and the actual tube current of the high-voltage unit (10); the host computer (11) adjusts the actual tube voltage of the high-voltage unit (10) to the high-voltage unit tube voltage threshold, and adjusts the actual tube current of the high-voltage unit (10) to the high-voltage unit tube current threshold.

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