CN116759280A - An X-ray source, CT scanner - Google Patents

Abstract

The application provides an X-ray source and a CT scanner. According to the X-ray source, the deflection electrode is added between the cathode and the anode, and the electron beam moves along a line on the anode under the control of the deflection electric field, so that the track of the electron beam on the anode is not a limited point but a continuous curve, the heat generated by the bombardment of the anode by the electron beam is uniformly distributed on the anode, and the service life of the anode is ensured; by arranging at least two deflection poles, the distance between the metal sheets of the deflection poles which are closer to the anode is larger, so that electron beams are prevented from being beaten on the metal sheets, the time of the electron beams under the action of deflection electric field force is prolonged, the coverage area of the electron beams on the anode is enlarged, and the requirement on the number of cathode electron guns is reduced. The CT scanner of the present application includes an X-ray source that can reduce the number of cathode electron guns to within 100 while avoiding the problem of image reconstruction artifacts due to the reduced number of cathode electron guns.

Description

An X-ray source, CT scanner

Technical field

The present invention relates to the technical field of medical devices, and in particular, to an X-ray source and a CT scanner.

Background technique

CT is widely used in clinical practice. In order to achieve tomographic imaging, traditional CT generally rotates the X-ray source (X-ray tube + high-voltage power supply) and detector system around the human body to obtain the projection data of the imaging object at different viewing angles, and then uses algorithms to reconstruct the image and obtain the tomographic image. Since the rotating anode X-ray tube of CT is restricted by centrifugal force, although one scan can now be completed within 0.25 seconds, the rotation speed is close to the theoretical limit and it is difficult to achieve effective improvement. Otherwise, the X-ray tube will be damaged. However, this speed still cannot fully meet the imaging requirements of moving organs or tissues such as the heart.

In order to solve the above problems, the prior art discloses a solution, which uses an annular X-ray source with a rotating detector system to overcome the problems caused by the rotation of the X-ray source by "the X-ray source is stationary and the detector rotates" Various technical limitations. When CT is working, the annular X-ray source is in a stationary state on the gantry, and the detector system and collimator rotate together with the turntable. In this scheme, the electron beam generated by the cathode finally hits a point on the anode target surface. This point is called the focus; in this scheme, one cathode corresponds to one anode focus, which will lead to two problems: (1) the anode is easily damaged, the life of the X-ray source will be very short, and the electron beam of the same cathode is always hitting the same At an anode focus, if the intensity of the electron beam is very high and the heat cannot be conducted away, the anode target will be directly broken down, causing the anode to be damaged. This is also the reason why the rotating anode X-ray tube appears after the beam current of the upper cathode electron beam increases. The reasons; (2) The number of cathode electron guns is required and the cost is very high. An anode focus can only produce one projection angle. From the perspective of image reconstruction, clinical CT imaging requires many projection angles, at least 300 or more. Otherwise, cross-sectional images are prone to artifacts due to sparse data, which can lead to misdiagnosis. This means that the solution requires a large number of cathode electron guns, at least 300, and the cost will be very high.

Based on the shortcomings of the current CT scanner, it is necessary to improve this.

Contents of the invention

In view of this, the present invention proposes an X-ray source and a CT scanner to solve the technical problems existing in the prior art.

In a first aspect, the present invention provides an X-ray source, including a cathode electron gun and an anode arranged in sequence, with at least one deflection electrode spaced between the cathode electron gun and the anode in a direction from the cathode electron gun toward the anode. ;

The deflection electrode is electrically connected to a deflection voltage source;

Wherein, the cathode electron gun is used to generate electron beams which are deflected by the deflection pole and then bombard the anode to generate X-rays.

Preferably, in the X-ray source, the deflection pole includes two oppositely arranged metal sheets, and the metal sheets are electrically connected to the deflection voltage source.

Preferably, in the X-ray source, at least two deflection poles are spaced between the cathode electron gun and the anode, and the spacing between the metal sheets of the deflection poles in the direction toward the anode gradually increases.

Preferably, in the X-ray source, the distance difference between the metal plates of two adjacent deflection poles is 0.5 to 1.5 cm.

Preferably, the X-ray source and the cathode electron gun include a cathode, a grid and a focusing electrode arranged in sequence, the cathode is used to generate an electron beam, the grid is used to control the emission of the electron beam, and the The focusing pole is used to control the focus of the electron beam.

In a second aspect, the present invention also provides a CT scanner, including:

The X-ray source;

A detector is located on one side of the X-ray source, and is used to receive X-rays generated by the X-ray source.

Preferably, the CT scanner includes:

A frame, a plurality of the X-ray sources are arranged on the frame;

A turntable is located on one side of the frame. A plurality of the detectors are arranged on the turntable. The turntable is provided with a rotating shaft. The turntable can rotate around the rotating shaft. The rotation of the turntable drives the detection. The device rotates.

Preferably, in the CT scanner, a plurality of the X-ray sources are arranged on the frame along the circumferential direction.

Preferably, in the CT scanner, the detector is arc-shaped, and a plurality of detectors are arranged on the turntable along the circumferential direction.

Preferably, in the CT scanner, a collimator is provided on the turntable between any two adjacent detectors, a collimator is provided on the collimator, and X-rays pass through the collimator The slit imaging object is incident on the detector corresponding to the collimator.

An X-ray source and CT scanner of the present invention have the following beneficial effects compared with the existing technology:

1. The X-ray source of the present invention adds a deflection pole between the cathode and the anode to prevent the electron beam from hitting the same position on the anode target. Through the control of the deflection electric field, the electron beam is allowed to move along a line on the anode. , so that the trajectory of the electron beam on the anode is no longer a finite point, but a continuous curve. The heat generated by the electron beam bombarding the anode is evenly distributed on the anode, ensuring the life of the anode;

2. The X-ray source of the present invention is provided with at least two deflection poles, and the distance between the metal sheets of the deflection poles closer to the anode is larger to prevent the electron beam from hitting the metal sheet, thus extending the electron beam. The time under the deflection electric field force expands the coverage of the electron beam at the anode and reduces the need for the number of cathode electron guns;

3. The CT scanner of the present invention includes an X-ray source, which ensures that the heat generated by electron beam targeting is evenly distributed on the anode target, protects the anode target, and extends the life of the CT scanner; the X-ray source provides sufficient The projection angle can reduce the number of cathode electron guns to less than 100, while avoiding the image reconstruction artifact problem caused by the reduction of the number of cathode electron guns.

Description of the drawings

In order to more clearly explain the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings needed to describe the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without exerting creative efforts.

Figure 1 is a schematic three-dimensional structural diagram of an X-ray source in one embodiment of the present invention;

Figure 2 is a schematic plan view of the X-ray source in one embodiment of the present invention;

Figure 3 is a schematic structural diagram of a cathode electron gun and a deflection electrode in one embodiment of the present invention;

Figure 4 is a schematic diagram of the voltage change of the deflection pole in one embodiment of the present invention;

Figure 5 shows the influence of the excessive length of the metal piece of the deflection pole of the present invention on the electron beam trajectory;

Figure 6 shows the influence of the short length of the metal piece of the deflection pole of the present invention on the electron beam trajectory;

Figure 7 is a schematic structural diagram of an X-ray source in another embodiment of the present invention;

Figure 8 is a schematic structural diagram of an X-ray source in another embodiment of the present invention;

Figure 9 is a schematic structural diagram of a CT scanner in the prior art;

Figure 10 is a schematic structural diagram of one view of a CT scanner in one embodiment of the present invention;

Figure 11 is a schematic structural diagram of another view of a CT scanner in one embodiment of the present invention;

Figure 12 is a schematic structural diagram of another view of a CT scanner in one embodiment of the present invention;

Figure 13 is an enlarged view of the circle in Figure 12;

Figure 14 is a cross-sectional view of a CT scanner in one embodiment of the present invention;

Figure 15 is a schematic diagram of three X-ray sources working simultaneously;

Figure 16 is a schematic diagram of the focus coverage produced by the cathode electron gun on the anode.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. The components of the embodiments of the invention generally described and illustrated in the figures herein may be arranged and designed in a variety of different configurations.

Therefore, the following detailed description of the embodiments of the invention provided in the appended drawings is not intended to limit the scope of the claimed invention, but rather to represent selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present invention.

It should be noted that similar reference numerals and letters represent similar items in the following figures, therefore, once an item is defined in one figure, it does not need further definition and explanation in subsequent figures.

In the description of the present invention, it should be understood that the orientation or positional relationship such as "up" is based on the orientation or positional relationship shown in the drawings, or is the orientation or positional relationship where the product of the invention is customarily placed when in use. , or the orientation or positional relationship commonly understood by those skilled in the art, is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. , therefore cannot be construed as a limitation of the present invention.

Those skilled in the art will understand that, unless expressly stated otherwise, the singular forms "a", "an", "the" and "the" used herein may also include the plural form. It should be further understood that the word "comprising" used in the description of this application refers to the presence of stated features, integers, steps, operations, elements and/or components, but does not exclude the presence or addition of one or more other features, Integers, steps, operations, elements, components and/or groups thereof. It will be understood that when we refer to an element being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. Additionally, "connection" as used herein may include wireless connections. As used herein, the term "and/or" includes all or any unit and all combinations of one or more of the associated listed items.

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

The present invention provides an X-ray source 1, as shown in Figures 1 to 3, including a cathode electron gun 11 and an anode 12 arranged in sequence. There is at least one deflection pole 13;

The deflection pole 13 is electrically connected to a deflection voltage source (not shown);

Among them, the cathode electron gun 1 is used to generate electron beams, which are deflected by the deflection pole 13 and then bombard the anode 12 to generate X-rays.

The X-ray source of the present invention includes a cathode electron gun 11 and an anode 12. The space between the cathode electron gun 11 and the anode 12 is in the direction from the cathode electron gun 11 to the anode 12 (from right to left in Figure 2, in Figures 7-8 direction from top to bottom), at least one deflection pole 13 is provided at intervals. Specifically, the number of deflection poles 13 can be determined according to actual use conditions. For example, the number of deflection poles 13 can be 1, 2, 3, 4, 5...n pieces; and the deflection pole 13 is electrically connected to the deflection voltage source, and the voltage of the deflection pole 13 is controlled by the deflection voltage source, thereby deflecting the electrons in the deflection 3; specifically, one deflection pole 13 respectively Electrically connected to one deflection voltage source, one deflection voltage source can also be used to electrically connect multiple deflection poles 13 , that is, one deflection voltage source can be used to individually control the voltage of one deflection pole 13 , or one deflection voltage source can be used to control multiple deflections. The voltage of pole 13; the cathode electron gun 1 generates an electron beam, and controls the voltage of deflection pole 13 through the deflection voltage source to control the intensity of the deflection electric field. Through the control of the deflection electric field, the electron beam is allowed to move along a line on the anode, preventing the electron beam from moving along the anode. Hit the same position on the anode, so that the trajectory of the electron beam on the anode is no longer a limited point, but a continuous curve. The heat generated by the electron beam bombarding the anode is evenly distributed on the anode, ensuring the life of the anode. It also adds enough projection angles; at the same time, the number of projection angles can be determined according to the needs of image reconstruction according to the CT system.

In some embodiments, as shown in FIG. 3 , the deflection pole 13 includes two oppositely arranged metal sheets 131 , and the metal sheets 131 are electrically connected to the deflection voltage source.

Specifically, in the above embodiment, two oppositely arranged metal pieces 131 are electrically connected to the positive and negative electrodes of the deflection voltage source respectively to control the voltage and electric field intensity of the deflection pole 13 .

As shown in Figure 4, it shows the voltage change of the deflection pole 13 controlled by the deflection voltage source. Specifically, the voltage U of the deflection pole 13 is controlled to change periodically with time t. For example, in practice, the deflection voltage of the deflection pole 13 is -2. Between 10,000 volts and +20,000 volts.

In some embodiments, at least two deflection poles 13 are spaced between the cathode electron gun 11 and the anode 12 , and the spacing between the metal pieces 131 of the deflection poles 13 in the direction toward the anode 12 gradually increases.

Specifically, in the above embodiment, the distance between the metal pieces 131 of the deflection pole 13 in the direction toward the anode 12 gradually increases; because under the same deflection voltage, the distance between the two metal pieces of the deflection pole is The closer the electron is, the stronger the electric field is, and the stronger the lateral deflection force the electron is subjected to. When the electron moves the same distance in the direction of the vertical deflection electric field, the distance it moves along the deflection direction is greater; as shown in Figure 5, if it is deflected The metal piece 131 of the pole 13 is too long (the length here refers to the height of the metal piece 131 in Figures 7-8, that is, the height of the metal piece 131 in the direction from the cathode electron gun 11 to the anode 12), and the two metal pieces The plates 131 are respectively connected to the positive and negative electrodes of the deflection voltage source. An electric field E is generated between the two metal plates 131. The electron beam e is deflected under the action of the electric field E and hits the metal plate 131 of the deflection pole 13 and is deflected. The metal piece 131 of the pole 13 absorbs; as shown in Figure 6, if the metal piece 131 of the deflection pole 13 is too short, the deflection force experienced by the electron beam e is too short, and the final deflection amplitude on the anode 12 is too small, covering If the range is not enough, the ring source will require a large number of cathode electron guns, which increases the cost of the system. By arranging at least two deflection poles 13, and the distance between the metal sheets 131 of the deflection pole 13 that is closer to the anode 12 is larger, the electron beam is prevented from hitting the metal sheet 131, thus prolonging the deflection electric field force of the electron beam. The action time expands the coverage of the electron beam on the anode and reduces the demand for the number of cathode electron guns 11.

Specifically, the length of the metal piece 131 of the deflection pole 13 in the present invention (the length here refers to the height of the metal piece 131 in Figures 7-8) can be determined according to the actual use situation. For example, the length of the metal piece 131 is 0.8-1.2 cm.

Further, please refer to FIG. 3 again. Two deflection poles 13 are arranged in sequence at the front end of the cathode electron gun 11, and the distance between the metal pieces 131 close to the deflection pole 13 of the cathode electron gun 11 is smaller than the distance between the deflection pole 13 far away from the cathode electron gun 11. The distance between the metal pieces 31.

In some embodiments, the spacing difference between the metal sheets 131 of two adjacent deflection poles 13 can be determined according to actual usage conditions, for example, the spacing difference between the metal sheets 131 of two adjacent deflection poles 13 0.5～1.5cm.

Specifically, if the X-ray source includes two deflection poles 13, the distance between the metal pieces 131 of the deflection pole 13 of the cathode electron gun 11 is 0.8-1.2 cm, and the distance of the metal pieces 131 of the deflection pole 13 of the anode 12 is close to 1.8~2.2cm, so that the distance difference between the metal sheets 131 of the two deflection poles 13 is 0.6~1.4cm.

In some embodiments, the cathode electron gun 11 includes a cathode 111, a grid 112, and a focusing electrode 113 arranged in sequence; the cathode 11 is used to generate an electron beam, the grid 112 is used to control the emission of the electron beam, and the focusing electrode 113 is used to control the electron beam. beam focus.

Specifically, the cathode 111 can adopt the thermionic emission mode or the field emission mode; when the thermionic emission mode is used, the cathode 111 adopts a cathode with high thermal electron emission efficiency, which includes a lanthanum hexaboride cathode, barium tungsten (such as Aluminate, tungstate, scandate, etc.) cathode, oxide (such as ternary carbonate containing Ba, Sr, Ca) cathode, etc.

In some embodiments, the material of the anode 12 may be copper, tungsten, molybdenum, rhenium, graphite, etc.

In some embodiments, the anode 12 includes an anode base and a tungsten target located on the anode base. The electron beam bombards the tungsten target on the anode 12 to generate X-rays.

Further, with reference to Figures 7 to 8, the X-ray source includes a cathode 111, a grid 112, a focusing pole 113, a deflection pole 13, and an anode 12; among them, a deflection pole 13 is shown in Figure 7, and a deflection pole 13 is shown in Figure 8. 2 deflection electrodes 13; when the cathode is in the hot electron working mode (that is, the cathode is a hot cathode material), the cathode 111 is heated to the temperature of emitting the hot electron beam (generally above 1000°C). At the same time, An electric field is loaded between the cathode 111 and the grid 112. The direction of the electric field is from the cathode 111 to the grid 112. The voltage range is 100V ~ 1000V. The purpose is to suppress the emission of the thermal electron beam; an electric field is loaded between the anode 12 and the grid 112. The electric field The direction is from the anode 12 to the grid 112, and the voltage range is 60kV ~ 140kV. It is used to accelerate the hot electron beam entering this area, allowing it to bombard the anode 12 to generate X-rays; when the electron beam enters the deflection pole 13, it passes through the deflection voltage source The voltage of the deflection electrode 13 is controlled to control the intensity of the deflection electric field. Through the control of the deflection electric field, the electron beam is allowed to move along a line on the anode, so that the trajectory of the electron beam on the anode is no longer a finite point, but a continuous curve. .

Based on the same inventive concept, the present invention also provides a CT scanner, including:

The above-mentioned X-ray source 1;

The detector 2 is located on the side of the X-ray source 40, and is used to receive the X-rays generated by the X-ray source 1.

The CT scanner of the present invention includes an X-ray source 1 and a detector 2. The detector 2 receives the X-rays generated by the X-ray source 1 and performs energy resolution on the X-rays.

Further, refer to Figure 9, which shows a schematic structural diagram of a CT scanner in the prior art, including: cathode 111, grid electrode 112, focusing electrode 113, anode 12, detector 2, and the electron beam e generated by the cathode 111 Finally, it hits a point on the surface of the anode 12, which is called the focus; the electron beam e bombards the anode 12 to generate X-ray a and shines on the detector 2 through the imaging object 5, where b is the focus plane. It can be clearly seen from Figure 9 that in the CT scanner in the prior art, the cathode has a short life and is easily damaged, and requires a large number of cathode electron guns and the cost is very high. However, using the CT scanner of the present invention, by connecting the cathode electron gun and the anode There is at least one deflection pole in between, so that the trajectory of the electron beam generated by the cathode electron gun on the anode is no longer a finite point, but a continuous curve. All these trajectories will form a circle on the annular anode, which is consistent with the rotation The effect of the anode X-ray tube is the same. It ensures that the heat generated by the electron beam target is evenly distributed on the anode, protects the anode and extends the life of the X-ray source; at the same time, it provides enough projection angles to allow the cathode to be The number of electron guns is reduced to less than 100, while image reconstruction artifact problems caused by the reduction in the number of cathode electron guns are avoided.

In some embodiments, the CT scanner includes:

Frame 3, multiple X-ray sources 1 are arranged on the frame 3;

The turntable 4 is located on one side of the frame 3. A plurality of detectors 2 are arranged on the turntable 4. The turntable is provided with a rotating shaft. The turntable can rotate around the rotating shaft. The rotation of the turntable 4 drives the detectors 2 to rotate.

In some embodiments, multiple X-ray sources 1 are disposed on the frame 3 along the circumferential direction.

In some embodiments, the detector 2 is arc-shaped, and multiple detectors 2 are arranged on the turntable 4 along the circumferential direction.

In some embodiments, a collimator 6 is provided on the turntable 4 between any two adjacent detectors 2, and a collimation slit is provided on the collimator 6. X-rays pass through the collimation slit and are incident on the imaging object and to The collimator 6 corresponds to the detector 6 .

Specifically, in the above embodiment, multiple X-ray sources 1 are arranged on the frame 3 along the circumferential direction, so that a ring-shaped X-ray source is formed between the multiple X-ray sources 1, and multiple detectors 2 are arranged on the frame 3 along the circumferential direction. On the turntable 4, and the turntable can rotate to drive the detector 2 to rotate, the rotation direction can be clockwise or counterclockwise, and the direction of rotation must match the direction of the electric field change of the deflection pole; while the frame 3 is fixed, so the frame 3 The X-ray source 1 above remains stationary; the field of view of the collimator 6 just covers the detector 2 on the opposite side, and its function is to control the irradiation range of X-rays through absorption. All X-rays outside the receiving range of the detector 2 are collimated The purpose is to reduce the radiation dose absorbed by the patient.

Furthermore, the specific manner in which the X-ray source 1 is installed on the frame 3 and the rotation of the detector 2 driven by the turntable 4 can be implemented using existing technologies; as shown in Figures 10 to 14, which show one of the X-ray sources 1, Schematic diagram of the specific connection method of the frame 3, detector 2, and turntable 4; specifically, Figures 10 to 12 are structural schematic diagrams of the CT scanner in different views, Figure 13 is an enlarged view of the circle in Figure 12, and Figure 14 is a cross-sectional view; Among them, the frame 3 is in the shape of a ring, and multiple X-ray sources 1 are arranged on the ring-shaped frame 3 along the axial direction. The turntable 4 is located in the ring-shaped frame 3. The number of detectors 2 and collimators 6 is There are three turntables 4 arranged alternately. The turntable 4 can rotate around the rotating bearing 41 (ie, the rotating shaft), thereby driving the detector 2 and the collimator 6 to rotate. The X-ray b generated by the X-ray source 1 passes through the collimation slit. The imaged object is incident on the detector 6 corresponding to the collimator 6 and is absorbed by it.

The X-ray source and CT scanner of the present invention will be further described below with specific embodiments. This section further explains the present invention in conjunction with specific examples, but should not be understood as limiting the present invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art. Unless otherwise specified, the methods and equipment used in the present invention are conventional methods and equipment in the art.

Example 1

The embodiment of the present application provides an X-ray source, whose structure is shown in Figure 1 and includes two deflection poles. The distance between the cathode and the anode of the cathode electron gun is 10 cm, and there is a gap between two metal sheets of the deflection pole close to the cathode. The distance between the two metal pieces of the deflection pole close to the anode is 2cm. The length of the metal piece of the deflection pole is 1cm. The deflection voltage source controls the voltage range of the deflection pole from -20,000 volts to +20,000 volts. volt;

The embodiment of the present application also provides a CT scanner, the structure of which is shown in 10 to 14, in which the X-ray source is the X-ray source in Embodiment 1, and the number of detectors and collimators is three;

Using the above-mentioned CT scanner, the coverage area of the electron beam on the anode can exceed 7cm, and the number of electron guns required for the entire CT scanner can not exceed 60;

The specific workflow of the above CT scanner is as follows:

S1. Preparatory work, power on; energize and heat the cathode to reach the temperature for emitting hot electrons (usually around 1000 degrees Celsius); at the same time, load an electric field between the cathode and the grid, and the direction of the electric field is from the cathode to the grid. , the voltage range is 100V ~ 1000V, the purpose is to suppress the occurrence of hot electrons; an electric field is loaded between the anode and the grid, the direction of the electric field is from the anode to the grid, the voltage range is 60kV ~ 140kV, used to suppress the hot electrons entering this area Accelerate it and let it bombard the anode to produce X-rays. The detector is also powered on and enters working status;

S2. Rotation; the detector system and the collimator rotate together with the turntable. The rotation direction can be clockwise or counterclockwise. The rotation direction must match the direction of the electric field change of the deflection pole;

S3. Exposure; Assume that the turntable rotates clockwise and a certain collimation slit moves from left to right and enters the coverage area of the No. 1 cathode electron gun. First, adjust the voltage of the deflection pole corresponding to the No. 1 cathode electron gun so that its electron beam can hit to the far left of the coverage range; when the center of the collimation coincides with the far left end of the coverage range of the No. 1 cathode electron gun, let the electric field intensity between the cathode and the grid that suppresses hot electron emission decrease, or become zero; at this time , the suppressed hot electrons are emitted, pass through the grid, are accelerated under the high-voltage electric field between the grid and the anode, and bombard the anode to produce X-rays; then adjust the voltage of the deflection pole so that the focus on the anode moves from the left to the left Move to the right, and its moving speed should match the rotation speed of the collimator, so that the focus is always in the center of the collimation slit; when the center of the collimation slit reaches the right end of the coverage range of the No. 1 cathode electron gun, that is, 2 When the coverage range of the No. 1 cathode electron gun is at the far left end, the No. 1 cathode electron gun is turned off through the grid control voltage of the No. 1 cathode electron gun, and the electron gun no longer emits electrons; at this time, the No. 2 cathode electron gun starts working according to the process of the No. 1 cathode electron gun. .

Further, refer to Figure 15, which shows a schematic diagram of the simultaneous operation of three X-ray sources (i.e., cathode electron gun No. 1, cathode electron gun No. 21, and cathode electron gun No. 41); refer to Figure 16, which shows the cathode electron gun in Schematic diagram of the focus coverage produced on the anode. These focus trajectories C will form a circle on the annular anode.

The above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of the present invention. within the scope of protection.

Claims (10)

1. An X-ray source is characterized by comprising a cathode electron gun and an anode which are sequentially arranged, wherein at least one deflection electrode is arranged between the cathode electron gun and the anode at intervals in the direction from the cathode electron gun to the anode;

the deflection electrode is electrically connected with a deflection voltage source;

the cathode electron gun is used for generating electron beams, and bombards the anode to generate X rays after being deflected by the deflection electrode.

2. The X-ray source of claim 1, wherein the deflection electrode comprises two oppositely disposed metal plates electrically connected to the deflection voltage source.

3. An X-ray source as claimed in claim 2, characterized in that at least two deflection poles are arranged at intervals between the cathode electron gun and the anode, the spacing between the metal sheets of the deflection poles in the direction towards the anode increasing gradually.

4. An X-ray source as claimed in claim 3, characterized in that the distance difference between the metal sheets of adjacent two deflection poles is 0.5-1.5 cm.

5. An X-ray source according to any one of claims 1 to 4, wherein the cathode electron gun comprises a cathode for generating an electron beam, a grid for controlling the emission of the electron beam, and a focusing electrode for controlling the focusing of the electron beam, which are arranged in sequence.

6. A CT scanner, comprising:

an X-ray source as claimed in any one of claims 1 to 5;

and the detector is positioned at one side of the X-ray source and is used for receiving X-rays generated by the X-ray source.

7. A CT scanner according to claim 6, comprising:

a frame, a plurality of X-ray sources are arranged on the frame;

the rotary table is positioned on one side of the frame, the detectors are arranged on the rotary table, a rotary shaft is arranged on the rotary table, the rotary table can rotate around the rotary shaft, and the rotary table rotates to drive the detectors to rotate.

8. The CT scanner of claim 7, wherein a plurality of the X-ray sources are circumferentially disposed on the gantry.

9. The CT scanner of claim 7, wherein the detector is arcuate and a plurality of the detectors are circumferentially disposed on the turntable.

10. A CT scanner according to claim 9, wherein a collimator is provided on the turntable between any two adjacent detectors, the collimator being provided with a collimator through which X-rays are incident via the imaged object onto the detector corresponding to the collimator.