Reflection type microfocus X-ray tube

Abstract

The utility model relates to the technical field of micro-focus X-ray tubes, and provides a reflective micro-focus X-ray tube which comprises a cathode unit, an electron beam focusing unit and an electron beam reflecting unit which are connected in sequence, 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 utility model, the X-ray conversion efficiency and the ray precision can be ensured.

Description

TECHNICAL FIELD

[0001] The utility model relates to micro focal point ray tube technical field especially relates to a reflection type micro focal point X ray tube. BACKGROUND

[0002] With the development of nondestructive testing, the demand for high magnification and high quality images is increasing. Micro focal point X ray tube is mainly used for high detection precision, fine defect detection, and application fields cover aviation, aerospace electronic industry composite material plastic and light metal etc.

[0003] The micro focal point X ray tube mainly adopts the transmission type micro focal point X ray tube, at present, the transmission type micro focal point X ray tube, target pole unit is connected through target pole locking nut target pole and target pole seat. The target adopts transmission target, and the electron beam is directly bombarded on the target surface, and the transmission target is generally very thin. Therefore, there are technical problems such as poor heat dissipation, ray beam is not concentrated and the like.

[0004] In addition, the transmission type micro focal point X ray tube uses small power, and it is difficult to meet the requirements of high power and long-term use. UTILITY MODEL CONTENTS

[0005] The utility model mainly solves the technical problems such as poor heat dissipation, x ray beam is not concentrated, low power of prior art, and proposes a reflection type micro focal point X ray tube to ensure the conversion efficiency and ray precision of X ray.

[0006] The utility model provides a reflection type micro focal point X ray tube, which comprises: cathode unit, electron beam focusing unit and electron beam reflection unit connected in sequence;

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

[0008] The electron beam focusing unit comprises: focusing end face, center shaft, focusing coil shell and anode shell structure fixedly connected in sequence;

[0009] The focusing end face is fixedly connected with the cathode unit;The focusing end face has a focusing unit electron beam inlet;

[0010] The deflection coil group is arranged on the center shaft, and the center shaft has a first electron beam channel;

[0011] The focusing coil shell is provided with a focusing coil group, and the focusing coil shell has a second electron beam channel;

[0012] The anode shell structure has 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 confinement window, a cooling component and a conical target.

[0015] The input end of the confinement window is arranged in the focus coil shell and the electron beam outlet of the focus unit, and the output end of the confinement window extends above the cooling component.

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

[0017] The shielding window has a ray outlet, and the target window is arranged in front of the ray outlet of the shielding window.

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

[0019] Preferably, the cathode unit comprises a cathode shell and a cathode generating device arranged in the cathode shell.

[0020] The cathode shell is arranged with a connecting component and a molecular pump.

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

[0022] The high-voltage sleeve is arranged with the grid fixed seat at the top.

[0023] The filament assembly is arranged on the grid fixed seat; the grid cap is detachably arranged on the grid fixed seat; and the filament assembly is wrapped in the grid cap.

[0024] The filament assembly comprises a filament assembly shell, a filament, a ceramic seat and two pole pins.

[0025] The bottom of the pole pin is connected to the filament pole of the high-voltage sleeve; the pole pin is fixedly connected to the ceramic seat, and the top of the pole pin extends from the ceramic seat; and the top of the two pole pins is respectively connected to the two ends of the filament.

[0026] The ceramic seat is arranged with the filament assembly shell; and the filament assembly shell covers the filament, the ceramic seat and the pole pin.

[0027] The center of the filament assembly shell and the center of the grid cap are respectively arranged with an exit hole.

[0028] Preferably, the high-voltage sleeve is arranged with a high-voltage sleeve flange at the bottom.

[0029] The grid fixed seat is arranged with a plurality of snap spring mechanisms uniformly distributed in the circumferential direction; and the grid cap is detachably arranged on the grid fixed seat through the snap spring mechanisms.

[0030] The filament is directly welded and fixed on the pole needle; the filament is in an obtuse angle shape; the filament assembly shell is fixed through the top wire and the ceramic base;

[0031] The common contact of the grid fixed base and the high voltage sleeve is connected; the grid fixed base is in contact with the grid cap and the filament assembly shell, and the grid cap is in contact with the filament assembly shell.

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

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

[0034] Compared with the prior art, the reflective microfocus X-ray tube has the following advantages:

[0035] 1. The electron beam reflection mechanism, the anode / cathode assembly and the sleeve arranged in series ensure the conversion efficiency and the ray precision of the X-ray, ensure the high-power use time of the ray tube, and overcome the defect that the transmission type microfocus ray tube cannot be used for a long time under high power.

[0036] 2. The target pole part adopts the electron beam reflection unit, the upper part of the conical target and the cooling part is provided with an inclined shielding window; the shielding window is provided with a ray outlet; the shielding window is provided with a target window in front of the ray outlet, and the shielding window is of a reflection type; the conical target is placed in the cooling part and is cooled, so that the electron beam can be effectively reflected. The utility model can emit high voltage and large current, and can change the direction of the electron beam.

[0037] 3. The cathode generating device of the utility model decomposes the structure into multiple component combinations, the filament can be replaced if the filament has a problem; the clamping spring mechanism and the top wire are arranged, so that the replacement of the filament is more convenient. The rear end of the high voltage sleeve is provided with a high voltage sleeve flange, the high voltage sleeve flange is connected with the cathode shell, the high voltage sleeve flange can drive the high voltage sleeve to be finely adjusted, the adjustment is convenient, and the requirement for assembly precision is reduced. The cathode generating device introduces the grid, can better control the tube current, and also plays a primary focusing role of the electron beam. The pole needle and the ceramic base are fixed through ceramic metallization connection, the connection problem of the ceramic and the electrode needle is solved, the influence of the third party medium on the quality and the influence on the vacuum in the open microfocus ray tube are avoided. The direct welding of the filament and the pole needle avoids the influence of the transition metal on the performance of the filament. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 is the arrangement schematic view of the reflective microfocus X-ray tube provided by the utility model;

[0039] Figure 2Is the structure diagram of the reflection type micro focus X-ray tube provided by the utility model;

[0040] Figure 3 Is the axial section view of the reflection type micro focus X-ray tube provided by the utility model;

[0041] Figure 4 Is the axial section view of the cathode unit provided by the utility model;

[0042] Figure 5 Is the axial section view of the cathode generating device provided by the utility model;

[0043] Figure 6 Is the axial section view of the electron beam focusing unit provided by the utility model;

[0044] Figure 7 Is the axial section view of the electron beam reflection unit provided by the utility model;

[0045] Figure 8 Is the emission schematic diagram of the electron beam reflection unit provided by the utility model.

[0046] 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 voltage-stabilized constant current source;8, detection unit;9, data acquisition unit;10, high voltage unit;11, upper computer;101, shielding window;102, target window;103, restraint window;104, cooling part;105, conical target;106, joint;201, focusing end face;202, central shaft;203, deflection coil group;204, focusing coil shell;205, focusing coil group;206, anode shell;207, deflection coil group shell;208, focusing unit electron beam entrance;209, focusing unit electron beam exit;210, connecting shell;401, grid cap;402, filament assembly shell;403, filament;404, ceramic seat;405, pole needle;406, top wire;407, clasp spring mechanism;408, grid fixed base;409, high voltage sleeve;410, high voltage sleeve flange;411, cathode shell;412, connecting part. DETAILED DESCRIPTION

[0047] In order to make the technical problems solved by the utility model, the technical scheme adopted and the technical effects reached more clear, the utility model is further explained in detail below in combination with the drawings and examples.It can be understood that the specific examples described here are only used to explain the utility model, and not limit the utility model.In addition, it needs to be explained that, for the convenience of description, only the parts related to the utility model are shown in the drawings, not all contents.

[0048] As Figures 1-3As shown, the utility model embodiment provides a reflection type micro focus X ray tube, which comprises: cathode unit 4, electron beam focusing unit 2 and electron beam reflection unit 1 connected in sequence.

[0049] The molecular pump 5 is installed on the cathode unit 4; specifically, the cathode shell 411 of the cathode unit 4 is installed with the molecular pump 5 through the connecting part 412. The molecular pump 5 provides vacuum extraction for the cathode unit 4, and the vacuum gauge 6 can detect the vacuum degree in the cathode unit 4 in real time and feed back to the upper computer 11.

[0050] As Figure 4 As shown, the cathode unit 4 comprises a cathode shell 411 and a cathode generating device arranged in the cathode shell 411.

[0051] As Figure 5 As shown, the cathode generating device comprises a grid cap 401, a filament assembly, a grid fixed base 408 and a high-voltage sleeve 409. The high-voltage sleeve 409 is an insulation part connected with high voltage, which can not only ensure the stability and safety of circuit connection, but also effectively prevent current leakage and electrical failure in the circuit. The high-voltage sleeve 409 has two filament poles and one common contact.

[0052] The grid fixed base 408 is fixedly arranged at the top of the high-voltage sleeve 409; and the high-voltage sleeve flange 410 is fixedly arranged at the bottom of the high-voltage sleeve 409. The cathode generating device is installed in the cathode shell 411 through the high-voltage sleeve flange 410.

[0053] The filament assembly is arranged on the grid fixed base 408; the grid cap 401 is detachably arranged on the grid fixed base 408; and the filament assembly is wrapped in the grid cap 401.

[0054] The filament assembly comprises a filament assembly shell 402, a filament 403, a ceramic seat 404 and two pole pins 405. The bottom of the pole pin 405 is connected with the filament pole of the high-voltage sleeve 409; the pole pin 405 is fixedly connected with the ceramic seat 404, and the top of the pole pin 405 extends from the ceramic seat 404; the top of each pole pin 405 is connected with the two ends of the filament 403; and the filament 403 is in an obtuse angle shape. The filament 403 is directly welded and fixed on the pole pin 405. Direct welding is adopted to remove the transition metal and eliminate the influence of the transition metal on stability.

[0055] The ceramic seat 404 is provided with a filament assembly shell 402; the filament assembly shell 402 covers the filament 403, the ceramic seat 404 and the pole needle 405; the filament assembly shell 402 and the center of the grid cap 401 are respectively provided with an exit hole.

[0056] The filament assembly shell 402 is fixed with the ceramic seat 404 through the top wire 406, so that the filament 403, the ceramic seat 404 and the pole needle 405 are fixed in the filament assembly shell 402. By adjusting and disassembling the top wire 406, the filament assembly is convenient to replace and disassemble.

[0057] The grid fixed seat 408 is uniformly distributed with a plurality of clamping spring mechanisms 407 in the circumferential direction; the grid cap 401 is detachably arranged on the grid fixed seat 408 through the clamping spring mechanism 407. Considering the frequent replacement of the filament assembly, the clamping spring mechanism 407 is arranged, and the grid cap 401 can be opened by pressing the clamping spring mechanism 407, so that the replacement of the filament is more convenient.

[0058] The pole needle 405 is fixed with the ceramic seat 404 through ceramic metallization connection. By selecting the material of the ceramic seat 404 and degassing treatment, the gas content in the ceramic seat 404 is reduced as much as possible, and the influence of the open type micro-focus ray tube on the limit vacuum is reduced. Through the ceramic metallization process, the connecting medium is changed, the high temperature resistance is improved, and the original defects are removed.

[0059] The grid fixed seat 408 is connected with the common contact of the high-pressure sleeve 409; the grid fixed seat 408 is in contact with the grid cap 401 and the filament assembly shell 402, and the grid cap 401 is in contact with the filament assembly shell 402. The grid cap 401, the filament assembly shell 402 and the grid fixed seat 408 are all made of metal material. Therefore, the grid cap 401, the filament assembly shell 402 and the grid fixed seat 408 can be electrically connected, the grid cap 401 can focus the electron beam by controlling the tube current, and the grid function is realized.

[0060] In the assembly, after the grid fixed seat 408 is fixed on the high-pressure sleeve 409, the filament assembly shell 402, the filament 403, the ceramic seat 404, the pole needle 405 and the top wire 406 are fixed on the high-pressure sleeve 409, and then the grid cap 401 is fixed through the clamping spring mechanism 407. The grid cap 401 wraps the filament assembly shell 402, the filament 403, the ceramic seat 404, the pole needle 405 and the top wire 406. In application, the entire cathode generating device is connected and fixed with the cathode shell 411 through the high-pressure sleeve flange 410.

[0061] This cathode generator connects high voltage to the filament 403 via a high-voltage sleeve 409, and the filament 403 emits an electron beam. The focusing of the electron beam is controlled by a grid cap 401, thus enabling the focused electron beam to smoothly enter the anode section of the open microfocus X-ray tube.

[0062] The cathode generator of cathode unit 4 is connected to high voltage unit 10. The high voltage unit 10 generates accelerating voltage and filament current, which are transmitted to grid cap 401 and filament 403 through high voltage cable. After the voltage is applied, the cathode generator generates an electron beam.

[0063] The electron beam focusing unit 2 and the cathode unit 4 are fixed together by a hinge assembly 3. The hinge assembly 3 facilitates the opening of the X-ray tube during use and maintenance.

[0064] like Figure 6 As shown, the electron beam focusing unit 2 includes a focusing end face 201, a central shaft 202, a focusing coil housing 204, and an anode housing, which are sequentially fixedly connected to form a 206. A connecting housing 210 is provided between the focusing end face 201 and the focusing coil housing 204 to ensure the airtightness of the electron beam focusing unit 2.

[0065] The focusing end face 201 is fixedly connected to the cathode unit 4; the focusing end face 201 has a focusing unit electron beam inlet 208; a deflection coil group 203 is arranged on the central shaft 202, and the central shaft 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 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.

[0066] The electron beam generated by the cathode unit 4 passes sequentially through the electron beam inlet 208 of the focusing unit, the first electron beam channel, and the second electron beam channel, before hitting the confinement window 103 of the electron beam reflecting unit 1. During the passage of the electron beam through the cathode unit 4, the deflection coil group 203 controls the direction of the electron beam, and the focusing coil group 205 controls the thickness of the electron beam by adjusting the current in the deflection coil group 203 and the focusing coil group 205.

[0067] like Figure 7As shown in the figure, the electron beam reflection unit 1 comprises a shielding window 101, a target window 102, a confinement window 103, a cooling component 104 and a conical target 105; the input end of the confinement window 103 is arranged in the focusing coil shell 204 and the electron beam outlet 209 of the focusing unit, the output end of the confinement window 103 extends above the cooling component 104; the conical target 105 is arranged in the axial direction of the cooling component 104, the top of the conical target 105 is provided with a conical reflection surface; the conical target 105 and the upper part of the cooling component 104 are provided with the shielding window 101 arranged in an inclined manner; the shielding window 101 is provided with a ray outlet 107; the target window 102 is arranged at the front end of the ray outlet of the shielding window 101. In addition, the bottom end of the conical target 105 is provided with a joint 106 for connecting a cooling water pump to realize the cooling of the conical target 105. The cooling water pump is electrically connected with the detection unit 8, and the detection unit 8 is used for detecting the temperature and flow of the cooling water.

[0068] In the electron beam reflection unit 1, as shown in the figure, Figure 8 The electron beam passes through the confinement window 103, hits on the conical reflection surface at the top of the conical target 105, the conical reflection surface changes the direction of the electron beam and makes the electron beam hit on the target window 102, X-rays are generated and transmitted through the target window 102 and then emitted from the ray outlet 107. The conical reflection surface arranged at the top of the conical target 105 changes the direction of the electron beam. The conical target 105 is arranged in the cooling component 104 and cooled to effectively reflect the electron beam.

[0069] The deflection coil group 203 and the focusing coil group 205 are electrically connected with the direct current stabilized constant current source 7, the direct current stabilized constant current source 7 has excellent performances such as ripple, output stability and response speed. The grid cap 401 is connected with the high voltage unit 10; the focusing end face 201, the central shaft 202, the focusing coil shell 204, the anode shell structure 206 and the deflection coil group 203 jointly form the ray source lens structure. The cathode generating device of the cathode unit 4 is electrically connected with the high voltage unit 10. The high voltage unit 10 applied in the microfocus system by the high frequency inverter power supply technology in the utility model makes the output ripple smaller, improves the imaging quality and reduces the influence of the distributed capacitance on the stable work of the system by adopting the sectional winding structure.

[0070] The working process of the utility model is as follows: the cathode generating device of the cathode unit 4 is connected with the high voltage unit 10, the upper computer 11 controls the high voltage unit 10 to pressurize the cathode generating device, the cathode generating device generates the electron beam after being electrified, the electron beam is emitted from the cathode unit 4 to the electron beam reflection mechanism 1 through the electron beam focusing unit 2, the electron beam hits on the target window 102 of the electron beam reflection mechanism 1, X-rays are generated and emitted from the ray outlet 107. After the X-rays are generated, the conical target 105 feeds back the real-time target current data to the data acquisition unit 9.

[0071] The molecular pump 5, the vacuum gauge 6, the electron beam reflection unit 1 and the high-voltage unit 10 are respectively electrically connected with a data acquisition unit 9, the data acquisition unit 9 is electrically connected with an upper computer 11, the data acquisition unit 9 collects feedback parameters of each part and uploads the upper computer 11 in real time, the data acquisition unit 9 has strong anti-interference ability, and the upper computer 11 is fed back with turbine speed, vacuum degree, target current, tube voltage and tube current data collected by the data acquisition unit 9. The specific control process is as follows:

[0072] The data acquisition unit 9 collects 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, the actual tube voltage of the high-voltage unit 10 and the actual tube current;

[0073] 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 upper computer 11; the upper computer 11 judges whether the turbine speed reaches the turbine speed threshold value and whether the vacuum degree reaches the vacuum degree threshold value, to decide whether the ray can be started. The molecular pump 5 and the vacuum gauge 6 are controlled to work by the upper computer 11, the vacuum degree inside the ray tube is ensured to reach the condition of generating rays, the filament generates a stable electron beam and the ray tube generates stable rays, the filament life is effectively prolonged and the stability of the ray source is improved.

[0074] The data acquisition unit 9 feeds back the target current of the electron beam reflection unit 1 to the upper computer 11; the upper computer 11 controls the direct-current stabilized constant-current source 7 to output a stabilized 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 stable electric field forces, the electron beam is controlled, the ray tube generates the best focal point size of the ray, and the ray tube reaches the best imaging effect.

[0075] The data acquisition unit 9 feeds back the actual tube voltage and the actual tube current of the high-voltage unit 10 to the upper computer 11; the upper computer 11 adjusts the actual tube voltage of the high-voltage unit 10 to the high-voltage unit tube voltage threshold value and adjusts the actual tube current of the high-voltage unit 10 to the high-voltage unit tube current threshold value.

[0076] After the above control of the upper computer 11, the ray is ensured to be normally used after being started, and the ray source is ensured to work safely.

[0077] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the utility model, and not to limit them; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: the technical solutions recorded in the foregoing embodiments are modified, or some or all of the technical features are replaced equivalently, without making the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the utility model.

Claims

1. A reflective microfocus X-ray tube, characterized in that, include: The cathode unit (4), electron beam focusing unit (2), and electron beam reflecting unit (1) are 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 face (201), a central shaft (202), a focusing coil housing (204), and an anode housing, which are fixedly connected in sequence (206); The focusing end face (201) is fixedly connected to the cathode unit (4); the focusing end face (201) has an electron beam inlet (208) for the focusing unit; A deflection coil group (203) is provided on the central shaft (202), and the central shaft (202) has a first electron beam channel; A focusing coil assembly (205) is provided 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 electron beam inlet (208), the first electron beam channel, the second electron beam channel, and the electron beam outlet (209) of the focusing unit are on the same straight line; The electron beam reflecting unit (1) includes: a shielding window (101), a target window (102), a restraint window (103), a cooling component (104), and a conical target (105); The input end of the restraint window (103) is placed in the focusing coil housing (204) and the electron beam outlet (209) of the focusing unit, and the output end of the restraint window (103) extends into the cooling component (104); The conical target (105) is positioned axially on the cooling component (104), and the top of the conical target (105) has a conical reflective surface; an inclined shielding window (101) is provided above the conical target (105) and the cooling component (104); The shielding window (101) has a radiation outlet (107); the shielding window (101) has a target window (102) installed at the front end of the radiation outlet.

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 by a hinge assembly (3).

3. The reflective microfocus X-ray tube according to claim 1, characterized in that, The cathode unit (4) includes: a cathode housing (411) and a cathode generating device disposed within the cathode housing (411); The cathode housing (411) is fitted 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 includes: a grid cap (401), a filament assembly, a grid fixing seat (408), and a high-voltage sleeve (409); A gate fixing seat (408) is fixedly installed on the top of the high-voltage sleeve (409); A filament assembly is disposed on the gate holder (408); a gate cap (401) is detachably disposed on the gate holder (408); the gate cap (401) encloses the filament assembly. The filament assembly includes: a filament assembly housing (402), a filament (403), a ceramic base (404), and two electrode pins (405); The bottom of the electrode (405) is connected to the filament electrode of the high-pressure sleeve (409); the electrode (405) is fixedly connected to the ceramic seat (404), and the top of the electrode (405) extends out of the ceramic seat (404); the tops of the two electrode (405) are respectively connected to the two ends of the filament (403). The ceramic base (404) is provided with a filament assembly housing (402); the filament assembly housing (402) covers the filament (403), the ceramic base (404) and the electrode (405); The filament assembly housing (402) and the grid cap (401) each have an emission hole at their center.

5. The reflective microfocus X-ray tube according to claim 4, characterized in that, The high-pressure sleeve (409) is fixedly provided with a high-pressure sleeve flange (410) at its bottom; The gate holder (408) has a plurality of snap ring mechanisms (407) evenly distributed in the circumferential direction; the gate cap (401) is detachably mounted on the gate holder (408) through the snap ring mechanisms (407); The filament (403) is directly welded and fixed to the electrode needle (405); the filament (403) is obtuse-angled; the filament assembly housing (402) is fixed to the ceramic base (404) by a set screw (406); The gate holder (408) is connected to the common contact of the high voltage sleeve (409); the gate holder (408) is in contact with the gate cap (401) and the filament assembly housing (402), and the gate cap (401) is in contact with the 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 the DC regulated constant current source (7).

Images