CN105047509A - Focusing device for large-beam-current electronic beam targeting X-ray source with micro beams - Google Patents

Abstract

The invention discloses a focusing device for a large beam current electron beam targeting a micro-beam spot X-ray source, including an electron beam channel tube, a condenser lens module, a transition section module, an objective lens module, a movable diaphragm module, an objective lens diaphragm seat and a target; The upper end is connected with the electron gun, and the lower end is fixedly connected with the transition section module; the lower end of the transition section module is fixedly connected with the objective lens module, and the lower end of the objective lens module is sleeved with the objective lens diaphragm seat, and a movable diaphragm is installed inside the objective lens diaphragm seat. There are 2 movable diaphragm modules, and half V-shaped holes are symmetrically opened in the center of the ends; when the diaphragm moves left and right, through the control of the overlapping area, continuous apertures of different sizes are formed. The electron beam passes through the electron beam channel tube from top to bottom sequentially through the condenser module, the transition section module, the objective lens module and the movable diaphragm module, and reaches the target plane; X-rays are generated by bombarding the target; the advantage is that the high-precision movable light The aperture size of the aperture enables fast switching of electron beams with different beam spot diameters.

Description

Focusing device for high-current electron beam targeting micro-spot X-ray source

technical field

The invention belongs to the technical field of three-dimensional non-destructive microscopic observation, and in particular relates to a focusing device for a large-beam electron beam targeting a micro-beam spot X-ray source.

Background technique

The micro-spot X-ray source is one of the necessary components for producing high-definition X-ray fluoroscopy microscopic images. There are usually two ways to generate micro-beam spot X-ray sources: one is the combination of ordinary X-ray tubes and X-ray optical components; however, X-ray optical components have high requirements in terms of material performance and stability, and how to reduce the The loss of useful X-ray photons transmitted from various X-ray optical components to the sample and its thermal load; when installing, consider whether there is strain, whether the positioning is accurate, and the overall stability of the optical components; the second is to move at high speed The electron beam converges into a micro-focus, which bombards the metal target surface to generate X-rays with tiny beam spots, that is, "fine-focus X-ray source"; due to its low cost and easy control, it is widely used in X-ray microscopic imaging and X-ray micro-CT and other fields.

"Fine focus X-ray source" usually adopts a two-stage lens focusing system. The magnetic lens closer to the target plane is called the objective lens, and the magnetic lens farther away from the target plane is called the condenser lens. The energy, beam current and beam spot of the incident electron beam at the target surface determine the intensity and distribution of the X-ray beam after they interact with the target. Therefore, designing and optimizing the two-stage lens focusing system to obtain a small beam spot while ensuring the electron beam current on the target surface has always been the goal of the "fine-focus X-ray source" workers.

In the two-stage lens fine-focus X-ray source, the performance of the electron beam at the target surface is affected by the factors of the objective lens index, the condenser lens index and the Coulomb force effect between the electrons, resulting in a very complicated switching process of the electron beam current, which is not conducive to the realization of dynamic Real-time observation of the process; and the interaction between the objective lens and the condenser, it is difficult to achieve independent adjustment; at the same time, when the micro-focus spot X-ray source is used for CT imaging detection, the position between the micro-focus spot X-ray source and the detector is fixed. Under certain conditions, the size of the field of view is inversely proportional to the resolution, that is, a large field of view has a low resolution; a small field of view has a high resolution. During detection, the sample is generally scanned with a large field of view and low resolution, and then the area of interest is selected to detect the sample with a small field of view and high resolution according to the needs. Usually, the multi-dimensional workpiece table is used to move the sample to make the X-ray source and the object The distance between the measured samples and between the measured sample and the detector changes to realize the switching of the large and small field of view; due to the limitation of the motion response speed of the workpiece table carrying the sample, and if the quality of the sample is relatively large, it is difficult to achieve fast switching. The switching time will increase, which affects the detection efficiency of the sample, which is very unfavorable for the transient process that sometimes needs to detect the sample.

Contents of the invention

The present invention aims at using X-ray source for CT imaging detection, the detection field of view and resolution of the system cannot be taken into account at the same time, and at the same time, it is limited by the response speed of the movement of the workpiece table carrying the sample and the quality of the sample, and the required switching time is increased. It is beneficial to realize the real-time observation of the dynamic process. Based on the above reasons, the present invention proposes a two-stage lens focusing system device that can quickly switch the field of view and resolution, specifically a focusing device for targeting a micro-spot X-ray source with a large beam current electron beam.

A focusing device for a large-current electron beam targeting a micro-spot X-ray source, including an electron beam channel tube, a condenser lens module, a transition section module, an objective lens module, a movable diaphragm module, an objective lens diaphragm seat and a target.

The focusing device has a cylindrical structure as a whole, and the electron beam channel tube is a hollow tube, which is located on the central axis of the condenser module and the objective lens module; it includes an upper electron beam channel tube and a lower electron beam channel tube; the upper end of the upper electron beam channel tube is connected to the electron gun , the lower end of the upper electron beam channel tube passes through the condenser module; the upper end of the lower electron beam channel tube is connected with the condenser lens module, and the lower end of the lower electron beam channel tube passes through the objective lens module and is connected with the objective diaphragm seat; the upper electron beam channel tube is connected with the lower electron beam channel tube The channel pipes are socketed together.

The electron beam passes through the electron beam channel tube from top to bottom sequentially through the condenser lens module, the transition section module, the objective lens module and the movable diaphragm module, and reaches the target plane; X-rays are generated by bombarding the target.

The upper end of the condenser module is connected to the electron gun, and the lower end of the condenser module is fixedly connected to the transition section module;

The condenser module includes the condenser upper yoke, the condenser lower yoke, the condenser pole shoe assembly, the condenser coil assembly and the condenser sealing ring;

The upper yoke of the condenser and the lower yoke of the condenser are both hollow cylinders inside, fixedly placed with buckles, and sealed and isolated with the condenser sealing ring. The central axis of the upper and lower yokes of the condenser is the same as the central axis of the electron beam passage tube. The condenser pole piece assembly includes the condenser upper pole piece and the condenser bottom pole piece, both of which are hollow cylinders inside. The condenser upper and lower pole pieces are assembled into one body through the pole piece spacer magnetic ring, which is the same as the central axis of the electron beam channel tube; the condenser pole piece The horizontal centerline of the assembly is perpendicular to the central axis of the electron beam passage tube, and the position of the intersection is the position of the condenser. The condenser coil assembly is circular, including the condenser coil and the condenser frame, and is installed on the hollow part between the outside of the condenser pole shoe assembly and the upper and lower magnetic yokes of the condenser through the coil frame.

The transition section module adopts a hollow cylinder inside, and the central axis of the cylinder is the same as the central axis of the electron beam passage tube.

The lower end of the transition section module is fixedly connected to the objective lens module, and the objective lens module includes an objective lens upper module and an objective lens lower module, an objective lens coil assembly and an objective lens sealing ring; the objective lens upper module is in the shape of an inverted "mountain", and the objective lens lower module adopts a hollow cone inside.

The upper module of the objective lens and the lower module of the objective lens are fixedly placed with buckles, and the objective lens coil assembly is placed inside the hollow; the axisymmetric center of the upper module of the objective lens and the lower module of the objective lens is the same as the central axis of the electron beam channel tube, and a channel is opened on the axisymmetric center. for the electron beam to pass through.

The objective lens coil assembly is circular and placed on the objective lens sealing ring. The objective lens sealing ring is connected and fixed with the upper module of the objective lens through screws, and placed above the lower module of the objective lens at the same time; the upper module of the objective lens and the lower module of the objective lens form a gap in the horizontal direction. The intersection point of the central position of and the axis is the position of the objective lens;

The lower end of the objective lens module is sleeved with an objective lens diaphragm seat, and a movable diaphragm is installed inside the objective lens diaphragm seat.

There are 2 movable aperture modules, which are symmetrical left aperture adjustment module and right aperture adjustment module respectively. The left aperture adjustment module includes the driving part of the left aperture, the left aperture rod and the left aperture plate; The diaphragm adjustment module includes the driving part of the right diaphragm, the right diaphragm rod and the right diaphragm plate;

The driving part of the left diaphragm and the driving part of the right diaphragm are respectively installed on both sides of the objective lens diaphragm seat, and the left diaphragm rod and the right diaphragm rod are respectively connected with the driving part of the left diaphragm and the driving part of the right diaphragm. The aperture rod and the right aperture rod are respectively connected to the left aperture plate and the right aperture plate, and the left aperture plate and the right aperture plate are arranged symmetrically relative to each other;

The objective lens diaphragm seat is in the form of a ring structure as a whole. The objective lens diaphragm seat and the lower end of the lower electron beam passage tube are connected by threads, and are located below the lower module of the objective lens. The central axis of the objective lens diaphragm seat is the same as the central axis of the electron beam passage tube. , the left and right diaphragms are placed in the center of the ring of the objective lens diaphragm seat, and two through holes are symmetrically opened on the sides of the objective lens diaphragm seat, which are used as channels for the left and right diaphragm rods to move left and right. The ends of the left diaphragm and the right diaphragm are respectively symmetrically opened with V-shaped gaps, and the symmetrical left and right diaphragms are superimposed on each other to form a small hole; the driving part of the left diaphragm and the right diaphragm The drive part of the diaphragm controls the left and right diaphragm rods to move left and right respectively, and then drives the left diaphragm and the right diaphragm to move left and right. By controlling the superposition area of the left diaphragm and the right diaphragm, a continuous difference is formed. Clear aperture of the size aperture. When the left aperture plate and the right aperture plate overlap completely, the minimum aperture is 0, and the hole formed when the left aperture plate and the right aperture plate are completely spliced together is the maximum aperture.

When the target is working, it is vacuum-adsorbed under the aperture seat of the objective lens. There is a concave on the surface, and a layer of heavy metal film is plated or sputtered on the concave.

The electron beam emitted by the electron gun passes through the condenser module, and forms a parallel beam under the action of the magnetic field formed by the upper and lower yokes of the condenser, the coil assembly of the condenser and the upper and lower pole pieces of the condenser; The appropriate aperture on the moving diaphragm module adjusts the incident angle of the electron beam on the target surface, and changes the beam current size and beam spot size at the target plane; the electron beam passes through the objective lens module, and the objective lens module passes through the working distance and the current in the objective lens coil assembly The optimization of the X-ray beam with high intensity and brightness can ensure the large beam at the target plane to flow down the micro-beam spot; on the other hand, when the coil current of the condenser lens remains unchanged, the current of the objective lens coil can be fine-tuned to find a clear image of the electron at the target plane. The aperture of the aperture module changes quickly to complete the switching of the beam current; the electron beam bombards the target after passing through the aperture of the objective lens to generate X-rays.

The advantages of the present invention are:

(1) A focusing system device for targeting a micro-spot X-ray source with a large beam current electron beam. The objective lens module and the condenser lens module can independently adjust the excitation current of their respective coil components.

(2) A focusing system device for targeting a micro-spot X-ray source with a large beam current electron beam. The high-precision movable aperture aperture size can realize rapid switching of electron beams with different beam spot diameters.

Description of drawings

Fig. 1 is the overall structural diagram of the focusing system device of the present invention;

Fig. 2 is the structural representation of condenser lens module of the present invention;

Fig. 2 a is the structural representation of condenser lens pole shoe of the present invention;

Fig. 3 is the structural diagram of objective lens module of the present invention;

Fig. 4 is a schematic structural diagram of the movable diaphragm module of the present invention;

Fig. 4a is a schematic structural view of the left diaphragm of the present invention;

Fig. 4b is a structural schematic diagram of the right diaphragm plate of the present invention;

Fig. 5 is the structural diagram of objective lens diaphragm seat of the present invention;

Fig. 6 is a structural diagram of the target of the present invention;

Fig. 7 is a schematic diagram of parallel mode operation of the present invention;

Fig. 8 is a schematic diagram of the optical path of the movable diaphragm switching beam of the present invention;

101-Sealing ring a; 102-Compression nut; 103-Magnetic yoke on condenser; 104-Condenser pole shoe assembly; 1041-Condenser upper pole shoe; 1042-Condenser lower pole shoe; Condenser position; 105-condenser sealing ring; 106-condenser coil assembly; 1061-condenser coil; 1062-condenser frame; 107-sealing ring b; 108-condenser yoke; 203-objective lens lower module; 204-objective lens sealing ring; 205-sealing ring c, 206-sealing ring d; 207-objective lens position; 301-transition section; 401-left aperture adjustment module; 402-right aperture adjustment module; 4011-the driving part of the left diaphragm; 4012-the left diaphragm rod; 4013-the sealing ring of the left diaphragm; 4014-the left diaphragm; 4021-the driving part of the right diaphragm; 4022-the right diaphragm rod; 4023-right Diaphragm sealing ring; 4024-right diaphragm plate; 403-optical hole; 502-lower electron beam channel tube; 501-upper electron beam channel tube; 601-objective lens diaphragm seat; 602-sealing ring e; 603-seal Circle f; 604-target; 6041-heavy metal film;

Detailed ways

The present invention will be further described in detail with reference to the accompanying drawings and embodiments.

A focusing device for a large-current electron beam targeting a micro-spot X-ray source, including an electron beam channel tube, a condenser lens module, a transition section module, an objective lens module, a movable diaphragm module, an objective lens diaphragm seat and a target.

The focusing device has a cylindrical structure as a whole. As shown in Figure 1, the electron beam channel tube is located on the central axis of the focusing device as a whole, and is made of a hollow tube made of duralumin or copper. The electron beam channel tube includes an upper electron beam channel tube 501 and the lower electron beam channel tube 502; the upper end of the upper electron beam channel tube 501 is connected with the electron gun, and the lower end of the upper electron beam channel tube 501 passes through the condenser module; the upper end of the lower electron beam channel tube 502 is connected with the condenser module, and the lower electron beam channel tube 502 The lower end passes through the objective lens module and is threadedly connected with the objective lens aperture seat 601 ; the upper electron beam channel tube 501 and the lower electron beam channel tube 502 are socketed together.

The electron beam passes through the upper electron beam channel tube 501 and the lower electron beam channel tube 502 from top to bottom sequentially through the condenser module, the objective lens module and the objective lens diaphragm seat 601, and reaches the plane of the target 604; it is generated by bombarding the heavy metal film 6041 on the target 604 X-rays.

The condenser module is shown in Figure 2: it includes a condenser upper yoke 103, a condenser lower yoke 108, a condenser pole shoe assembly 104, a condenser seal ring 105 and a condenser coil assembly 106;

The condenser pole shoe assembly 104 is shown in Figure 2a, including the condenser upper pole shoe 1041 and the condenser lower pole shoe 1042, both of which are hollow cylinders inside, and a certain distance S2 is guaranteed when the two are installed, and the pole shoe is separated from the pole shoe by a magnetic ring 1043 is assembled into one; the horizontal centerline of the condenser pole shoe assembly 104 is perpendicular to the central axis of the upper electron beam passage tube 501, and the intersection position is the condenser position 1044; the cylinder diameter of the upper pole shoe 1041 of the condenser is D11, and the lower pole shoe of the condenser The cylinder diameter of 1042 is D21.

The upper yoke 103 of the condenser and the lower yoke 108 of the condenser all adopt internal hollow cylinders, which are buckled and placed, and are sealed and isolated with the condenser seal ring 105. There is a sealing ring b107; the electron gun and the yoke 103 on the condenser are fixed by a compression nut 102 and sealed with a sealing ring a101.

The condenser coil assembly 106 is installed between the hollow part in the middle of the condenser pole shoe assembly 104 and the upper and lower magnetic yokes of the condenser, the condenser coil assembly 106 comprises a condenser coil 1061 and a condenser skeleton 1062; the condenser coil assembly 106 is a ring, fixed on the condenser skeleton 1062 on.

The lower end of the yoke 108 under the condenser is connected to the transition section module and the lower electron beam passage tube 502, and the lower end of the transition section module is fixedly connected to the objective lens module. The condenser module is connected to the objective lens module through the transition section module, and the solid connections between the condenser lens module, the transition section module and the objective lens module are all connected by screws;

The transition section module includes a transition section 301, the transition section 301 adopts a hollow cylinder, and the central axis of the cylinder is the same as the central axis of the electron beam passage tube;

The objective lens module is shown in Figure 3: it includes an objective lens upper module 201 and an objective lens lower module 203, an objective lens coil assembly 202, and an objective lens sealing ring 204; The pole shoe is processed from a piece of pure iron or ductile iron; the lower module 203 of the objective lens is a hollow cone, and the lower yoke of the objective lens and the lower pole piece of the objective lens are processed from a piece of pure iron material or ductile iron; the upper module of the objective lens 201 and the objective lens lower module 203 are buckled, and the objective lens coil assembly 202 is placed inside the hollow; the axisymmetric center of the objective lens upper module 201 and the objective lens lower module 203 is the same as the central axis of the electron beam passage tube, and a channel is opened on the axisymmetric center , so that the electron beam passes through; the upper module 201 of the objective lens and the lower module 203 of the objective lens form a gap in the horizontal direction, and the intersecting point between the center position of the gap and the axis is the objective lens position 207; the upper and lower modules of the objective lens form the magnetic circuit of the objective lens module with the gap; The upper module 201 of the objective lens and the lower module 203 of the objective lens are equipped with a sealing ring c205 and a sealing ring d206 respectively.

The objective lens coil assembly 202 is circular and is made up of the objective lens coil skeleton and the objective lens coil; the objective lens coil assembly 202 is placed on the objective lens sealing ring 204, and the objective lens sealing ring 204 is connected and fixed with the upper module 201 of the objective lens by screws, and is placed on the objective lens at the same time. Above the lower module 203;

There are two movable aperture modules, as shown in Figure 4, which are symmetrical left aperture adjustment module 401 and right aperture adjustment module 402 respectively, the left aperture adjustment module 401 includes the driving part 4011 of the left aperture, the left aperture Diaphragm rod 4012, left diaphragm sealing ring 4013 and left diaphragm plate 4014; right diaphragm adjustment module 402 includes right diaphragm driving part 4021, right diaphragm rod 4022, right diaphragm sealing ring 4023 and right diaphragm plate 4024 ;

The driving part 4011 of the left diaphragm and the driving part 4021 of the right diaphragm are installed on the two bosses inside the objective lens diaphragm seat 601 respectively, and the left diaphragm rod 4012 and the right diaphragm rod 4022 are respectively connected with the driving part of the left diaphragm 4011 and the driving part 4021 of the right diaphragm, the left diaphragm rod 4012 and the right diaphragm rod 4022 are respectively provided with a left diaphragm sealing ring 4013 and a right diaphragm sealing ring 4023; the left diaphragm rod 4012 and the right diaphragm rod 4022 The left aperture plate 4014 and the right aperture plate 4024 are respectively connected, and the left aperture plate 4014 and the right aperture plate 4024 are symmetrically arranged opposite to each other.

As shown in Figure 4a and Figure 4b, the central positions of the ends of the left diaphragm 4014 and the right diaphragm 4024 are respectively symmetrically opened with a half-V-shaped hole, and the symmetrical left diaphragm 4014 and the right diaphragm 4024 mutually up and down. Superposition, the driving part 4011 of the left aperture controls the left and right diaphragm rod 4012 to move left and right, the driving part 4021 of the right diaphragm controls the right diaphragm rod 4022 to move left and right, and then drives the left diaphragm plate 4014 and the right diaphragm plate 4024 to move left and right, Control the overlapping area of the symmetrical left diaphragm 4014 and the right diaphragm 4024 to form continuous apertures 403 of different sizes. When the left diaphragm 4014 and the right diaphragm 4024 completely overlap, the aperture 403 The minimum value is 0, and the hole formed when the left aperture plate 4014 and the right aperture plate 4024 are completely spliced together is the maximum light aperture 403 .

Objective lens diaphragm seat 601 is shown in Figure 5, and the whole is circular ring structure, and the lower end of objective lens diaphragm seat 601 and lower electron beam channel tube 502 is connected by screw thread, is positioned at the below of module 203 under objective lens, and objective lens diaphragm 601 The central axis is the same as the central axis of the electron beam passage tube, and the objective lens aperture seat 601 is provided with a sealing ring e602.

The ring center of the objective lens diaphragm seat 601 places the left diaphragm plate 4014 and the right diaphragm plate 4024, the diameter is greater than or equal to the size after the left diaphragm plate 4014 and the right diaphragm plate 4024 are completely spliced. A through hole is respectively symmetrically opened on the sides, as a passage for the left and right diaphragm rods 4012 and 4022 to move left and right. The moving direction of the module is perpendicular to the axis of the central axis of the electron beam passage tube; the light through holes 403 with different diameters are formed by controlling the movement of the movable diaphragm module.

The structure of the target 604 is shown in Figure 6. It is provided with a sealing ring f603, and is sucked under the objective lens aperture seat 601 by vacuum during operation. The material of the target 604 is a light element, such as aluminum; A layer of heavy metal film 6041, such as tungsten, is plated or sputtered on the inner recess.

The electron beam passes through the magnetic field generated by the condenser lens module and the magnetic field generated by the objective lens module in sequence, and finally reaches the target plane. The moving diaphragm module and objective lens diaphragm seat 601 confines the electrons to the paraxial region of the condenser lens module and the objective lens module.

In the focusing system device of the large-beam electron beam targeting the micro-beam spot X-ray source, as shown in Figure 7, the parallel working mode of the two-stage focusing system is realized by setting the position of the condenser module and the objective lens module, the structural parameters and the excitation of the coil assembly. In this way, a small beam spot can be realized while ensuring a large beam current at the target surface.

A focusing device for a large-beam current electron beam targeting a micro-beam spot X-ray source, the optical path of the movable diaphragm module switching the beam current is shown in Figure 8, and the specific method is as follows:

Firstly, the structural parameters and electrical parameters of the objective lens module are obtained by setting the initial conditions of the focusing system device and optimizing the performance index of the electron beam at the target plane;

Then, set the structural parameters and electrical parameters of the condenser module to realize that the movement of the electron beam between the condenser module and the objective lens module is parallel to the optical axis. The two-stage lens focusing system in the mode can obtain the X-ray source with large beam current and micro-beam spot;

Finally, through the automatic switching of the movable diaphragm and the fine-tuning of the objective coil current, the rapid switching of electron beams with different beam spot sizes at the target surface of the large-beam micro-beam spot X-ray source is realized, which is used for real-time observation of samples.

Claims (8)

1. a focusing arrangement for large beam deflection target practice X-ray source with microbeam, is characterized in that, comprises electron beam channel pipe, condenser module, changeover portion module, objective lens module, movable diaphragm module, lens isis seat and target;

Condenser module upper end is fixedly mounted on electron gun lower end; Condenser module lower end is from top to bottom connected changeover portion module successively, objective lens module, lens isis seat and target, and electron beam channel pipe is positioned on the central axis of condenser module and objective lens module;

Condenser module comprises condenser upper magnet yoke, condenser lower yoke, condenser pole shoe member and condenser coil block, and electron beam, behind the magnetic field of condenser module generation, forms parallel beam;

Objective lens module comprises object lens upper module, object lens lower module and objective lens coil assembly; Electron beam is through objective lens module, and objective lens module, on the one hand by the optimization of electric current in operating distance and objective lens coil assembly, obtains the X-ray beam of high strength and brightness, microbeam spot under the large line in guarantee target plane place; Fine setting objective lens coil electric current, finds the electronics sharply defined image at target plane place on the other hand, coordinates the light hole of movable diaphragm module to change the switching completing line fast;

Described movable diaphragm module is arranged on lens isis seat, comprises the left diaphragm sheet and right diaphragm sheet that are oppositely arranged; The relative side place correspondence position of left diaphragm sheet and right diaphragm sheet has v-notch; Control left diaphragm sheet by driver part and right diaphragm sheet moves left and right, make mutually to superpose between the v-notch on left diaphragm sheet and right diaphragm sheet, form the light hole in different size aperture;

Electron beam from top to bottom successively through condenser module, changeover portion module, objective lens module and light hole, arrives target plane by electron beam channel pipe; X ray is produced by bombardment target.

2. the focusing arrangement of a kind of large beam deflection target practice X-ray source with microbeam as claimed in claim 1, is characterized in that, described electron beam channel pipe adopts hollow pipe, comprises electron beam channel pipe and lower electron beam channel pipe; Upper electron beam channel pipe and lower electron beam channel pipe box are connected together; Upper electron beam channel pipe upper end is connected with electron gun, and upper electron beam channel pipe lower end is through condenser module; Lower electron beam channel pipe upper end is connected with condenser module, and lower electron beam channel pipe lower end is connected with lens isis seat through objective lens module.

3. the focusing arrangement of a kind of large beam deflection target practice X-ray source with microbeam as claimed in claim 1, it is characterized in that, described condenser upper magnet yoke and condenser lower yoke make-up fixed placement, and isolate with condenser seal ring seal, on condenser, the axis of lower yoke is identical with the axis of electron beam channel pipe; Condenser pole shoe member to comprise on condenser pole shoe under pole shoe and condenser, is assembled into one by pole shoe magnetism-isolating loop, identical with the axis of electron beam channel pipe; The horizontal center line of condenser pole shoe member and the central axis upright of electron beam channel pipe, and position of intersecting point is condenser position; Condenser coil block is annular, comprises condenser coil and condenser skeleton, is arranged on the outside hollow space middle with lower yoke on condenser of condenser pole shoe member by bobbin.

4. the focusing arrangement of a kind of large beam deflection target practice X-ray source with microbeam as claimed in claim 1, is characterized in that, described object lens upper module is in falling " mountain " font, and object lens lower module adopts the cone of inner hollow;

Object lens upper module and object lens lower module make-up fixed placement, empty internal places objective lens coil assembly; Object lens upper module is identical with the central shaft of electron beam channel pipe with the axial symmetry center of object lens lower module, has passage in the heart, so that electron beam passes through in axial symmetry simultaneously;

Objective lens coil assembly is annular, is placed on object lens sealing ring, and object lens sealing ring is connected with object lens upper module and fixes, and is placed on above object lens lower module simultaneously; Object lens upper module and object lens lower module form gap in the horizontal direction, and the center in gap and the joining of axis are object lens positions.

5. the focusing arrangement of a kind of large beam deflection target practice X-ray source with microbeam as claimed in claim 1, it is characterized in that, when described left diaphragm sheet and right diaphragm sheet are completely overlapping, light hole is minimum is 0, when left diaphragm sheet and right diaphragm sheet be stitched together completely formed hole be maximum light hole.

6. the focusing arrangement of a kind of large beam deflection target practice X-ray source with microbeam as claimed in claim 1, it is characterized in that, by the below of vacuum suction at lens isis seat when described target works, be provided with indent on the surface, plate or sputter last layer heavy metal film at interior recess.

7. the focusing arrangement of a kind of large beam deflection target practice X-ray source with microbeam as claimed in claim 1, it is characterized in that, described movable diaphragm module is divided into symmetrically arranged left diaphragm adjustment module and right diaphragm adjustment module; Left diaphragm adjustment module comprises the driver part of left diaphragm, left diaphragm rod and left diaphragm sheet; Right diaphragm adjustment module comprises the driver part of right diaphragm, right diaphragm rod and right diaphragm sheet; The driver part of left diaphragm and the driver part of right diaphragm are arranged on the both sides of lens isis seat respectively, and left diaphragm rod two ends connect the driver part of left diaphragm and left diaphragm sheet respectively; Right diaphragm rod two ends connect the driver part of right diaphragm and right diaphragm sheet respectively.

8. the focusing arrangement of a kind of large beam deflection target practice X-ray source with microbeam as claimed in claim 1, it is characterized in that, described lens isis seat entirety is in cirque structure, left diaphragm sheet and right diaphragm sheet are placed in the circle ring center inside of lens isis seat, lens isis seat side respectively symmetry has two through holes, as the passage that left diaphragm rod and right diaphragm rod move left and right.