CN109449072B

CN109449072B - Floating target mechanism for ray source

Info

Publication number: CN109449072B
Application number: CN201811278692.0A
Authority: CN
Inventors: 邓友银; 董中林; 姚星佳; 张杨
Original assignee: CETC 38 Research Institute
Current assignee: CETC 38 Research Institute
Priority date: 2018-10-30
Filing date: 2018-10-30
Publication date: 2020-08-21
Anticipated expiration: 2038-10-30
Also published as: CN109449072A

Abstract

The invention discloses a floating target mechanism for a ray source, which comprises a ray source shell, a tube shell inner cover, a floating target, a target holder, an elastic compression tube and a driving mechanism, wherein the tube shell inner cover is arranged on the shell; the upper portion gas tightness of target stand connects the floating target, the lower part gas tightness of target stand connects the elasticity compression pipe, the target stand is located on the tube inner cover, the lower part gas tightness of tube inner cover is fixed on the ray source casing, the outside at tube inner cover is established to the elasticity compression pipe box, actuating mechanism one end is connected on the ray source casing, and the other end is connected on the target stand. The floating target mechanism is applied to a ray source, can effectively avoid the problem of target function failure caused by target surface pitting, greatly prolongs the service life of the target, and does not need to replace a target assembly within the service life cycle of the ray source.

Description

Floating target mechanism for ray source

Technical Field

The invention relates to an X-ray imaging technology, in particular to a floating target mechanism for a ray source.

Background

The X-ray source is a core component of an X-ray imaging system and is widely applied to the fields of packaging detection, material flaw detection, medical imaging and the like. The X-ray source has the main function of generating X-rays, and the principle is that electron beams generated by field emission or thermal electron emission in the source bombard a window target to generate the X-rays which are radiated outside the source through the window target.

The conventional radiation source window target is generally made of a tungsten-plated diamond sheet, X-rays are mainly generated by bombarding a tungsten coating on the surface of a diamond by high-energy electron beams, and the tungsten coating of the diamond window is bombarded by the high-energy electron beams for a long time, so that the coating is corroded in a pitting manner, and the target function is lost.

In order to ensure that the radiation source can work stably for a long time, a focus point of an electron beam on a target needs to be transferred regularly to avoid continuous bombardment of the electron beam at a certain target point.

However, in a vacuum environment, the displacement of the target material is difficult to realize, the adjusting time is too long, and the precision is not high, which is also a very difficult problem to solve.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the prior art can not adjust the position of a target material, and high-energy electron beams bombard a target surface for a long time to cause pitting corrosion of the target surface, thereby providing a floating target mechanism for a ray source.

The invention solves the technical problems through the following technical scheme, and the invention comprises a ray source shell, a tube shell inner cover, a floating target, a target holder, an elastic compression tube and a driving mechanism; the upper portion gas tightness of target stand connects the floating target, the lower part gas tightness of target stand connects the elasticity compression pipe, the target stand is located on the tube inner cover, the lower part gas tightness of tube inner cover is fixed on the ray source casing, the outside at tube inner cover is established to the elasticity compression pipe box, actuating mechanism one end is connected on the ray source casing, and the other end is connected on the target stand.

The driving mechanism comprises at least two driving pieces with the same structure, and the adjacent driving pieces are perpendicular to each other.

The driving mechanism is provided with two driving parts which are perpendicular to each other and arranged outside the radiation source shell. The adjustment in the X direction and the Y direction in the horizontal direction can be realized, and the maximum displacement distance is controlled by the step clearance reserved between the target holder and the inner cover of the tube shell.

The driving piece comprises a deflector rod, a deflector rod seat and an adjusting knob; one end of the shifting rod is connected to the outer edge of the target holder, the other end of the shifting rod is connected with the adjusting knob, the shifting rod holder is fixed outside the ray source shell, the shifting rod is hinged to the shifting rod holder, and the adjusting knob rotates to drive the elastic compression tube to move in the horizontal direction.

As one preferable mode of the invention, the middle part of the deflector rod is hinged on the deflector rod seat through a pin.

And graduation lines are carved on the adjusting knob. The position can be accurately controlled.

The elastic compression tube is internally vacuumized, the target holder is pressed on the tube shell inner cover, and at least one friction reducing mechanism is arranged at the pressing position of the target holder and the tube shell inner cover.

The friction reducing mechanism is a ball bearing. The atmospheric pressure borne by the floating target and the target holder is transmitted to the inner cover of the tube shell through the ball bearing to prevent the corrugated tube from longitudinally contracting

In a preferred embodiment of the present invention, the elastic compression tube is a bellows tube.

Compared with the prior art, the invention has the following advantages: the floating target mechanism is applied to a ray source, the problem of target function failure caused by target surface pitting can be effectively avoided, the service life of the target is greatly prolonged, and a target assembly does not need to be replaced within the service life cycle of the ray source;

the corrugated pipe structure is used, the problem that the air tightness of conventional moving parts cannot meet the requirement of ultrahigh vacuum is thoroughly solved, and the vacuum degree in the ray source is ensured to be lower than 1 × 10^-7An ultra-high vacuum environment of Pa;

the floating target has a simple and reliable driving structure, the problem of target function failure caused by target surface pitting is effectively solved, and a target assembly does not need to be replaced within the service life of the ray source;

the ball bearing is arranged between the target holder and the tube shell inner cover, so that the supporting structure of the floating target and the corrugated tube is greatly simplified, the problem of corrugated tube contraction deformation caused by the pressure difference between the inside and the outside of the ray source is solved, and the moving friction force between the target holder and the tube shell inner cover is reduced; the displacement of the floating target surface can be accurately adjusted by respectively adjusting the adjusting knobs positioned in the X direction and the Y direction, and the position of the electron beam bombarding the target surface is accurately controlled.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a cross-sectional view of the present invention;

fig. 3 is a partially enlarged view of a portion a in fig. 2.

Detailed Description

The following examples are given for the detailed implementation and specific operation of the present invention, but the scope of the present invention is not limited to the following examples.

As shown in fig. 1 to 3, the present embodiment includes a radiation source housing 1, an inner tube housing cover 2, a floating target 3, a target holder 4, an elastic compression tube 5 and a driving mechanism; the upper portion gas tightness welded connection floating target 3 of target seat 4, the lower part gas tightness welded connection elasticity compression pipe 5 of target seat 4, target seat 4 is located on tube inner cover 2, the lower part gas tightness welded of tube inner cover 2 is on launching casing 1, elasticity compression pipe 5 cover is established in the outside of tube inner cover 2, actuating mechanism one end is connected on launching casing 1, and the other end is connected on target seat 4. The resilient compression tube 5 of this embodiment is a bellows.

The driving mechanism has two driving members which are arranged perpendicularly to each other outside the radiation source housing 1. The adjustment in the X direction and the Y direction in the horizontal direction can be realized, and the maximum displacement distance is controlled by the step clearance reserved between the target holder 4 and the tube shell inner cover 2.

The driving piece comprises a driving lever 6, a driving lever seat 7 and an adjusting knob 8; one end of the deflector rod 6 is connected in a clamping groove on the outer edge of the target holder 4, the other end of the deflector rod is connected with an adjusting knob 8, the deflector rod holder 7 is fixed outside the ray source shell 1, the deflector rod 6 is hinged on the deflector rod holder 7 through a pin, and the adjusting knob 8 controls the stroke of the deflector rod 6 in a rotating mode to drive the elastic compression tube 5 to move in the horizontal direction.

The adjusting knob 8 is engraved with graduation lines. The position can be accurately controlled.

The elastic compression tube 5 is internally vacuumized, the target holder 4 is pressed on the tube shell inner cover 2, and a circle of ball bearing 9 is arranged at the pressing position of the target holder 4 and the tube shell inner cover 2. The atmospheric pressure borne by the floating target 3 and the target holder 4 is transmitted to the tube shell inner cover 2 through the ball bearing 9, and the longitudinal contraction of the corrugated tube is prevented.

The embodiment works as follows:

the ray source is vacuumized, the target holder 4 is pressed on the inner shell 2 of the tube shell, the bellows is compressed, and the ball bearing 9 transmits the atmospheric pressure born by the floating target 3 and the target holder 4 to the inner shell 2 of the tube shell to prevent the bellows from longitudinally shrinking.

When the position of the floating target 3 needs to be adjusted, the bellows can move along the left and right directions of the figure 1 by adjusting the adjusting knob 8 in the Y direction, so that the displacement in the Y direction is realized; the adjusting knob 8 for adjusting the X direction realizes that the corrugated pipe moves along the direction of the vertical paper surface of the figure 1, thereby realizing the displacement of the X direction and meeting the requirement of accurate and quick adjustment.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. A floating target mechanism for a ray source is characterized by comprising a ray source shell, a tube shell inner cover, a floating target, a target holder, an elastic compression tube and a driving mechanism; the upper part of the target holder is connected with a floating target in an airtight manner, the lower part of the target holder is connected with an elastic compression tube in an airtight manner, the target holder is positioned on an inner tube shell, the lower part of the inner tube shell is fixed on a radiation source shell in an airtight manner, the elastic compression tube is sleeved outside the inner tube shell, one end of the driving mechanism is connected to the radiation source shell, and the other end of the driving mechanism is connected to the target holder;

the driving mechanism comprises at least two driving pieces with the same structure, and the adjacent driving pieces are arranged vertically;

2. A floating target mechanism for a radiation source according to claim 1, wherein said driving mechanism comprises two driving members arranged perpendicularly to each other outside the radiation source housing.

3. A floating target mechanism for a radiation source as claimed in claim 1, wherein the central portion of said deflector rod is hinged to the deflector rod holder by a pin.

4. The floating target mechanism of claim 1, wherein the adjustment knob has graduation lines engraved thereon.

5. A floating target mechanism for radiation source as claimed in claim 1, wherein a vacuum is drawn in said elastic compression tube, said target holder is pressed against the inner envelope of the tube shell, and at least one friction-reducing mechanism is provided at the pressing position of said target holder and said inner envelope of the tube shell.

6. A floating target mechanism for a radiation source according to claim 5 wherein said friction reducing mechanism is a ball bearing.

7. A floating target mechanism for a radiation source according to claim 1 wherein said resiliently compressible tube is a bellows.