JPH03283338A - Electron gun heated type steam generator - Google Patents

Abstract

PURPOSE:To adjust an application position of an electron beam to an aimed position by detecting the spacial radiation intensity distribution of X-rays, and comparing the peak position of the distribution to a preset aimed position, and controlling an electron-beam application position setting means so that the difference between the peak position and the aimed position is zero. CONSTITUTION:A detection signal output from an X-ray two dimensional detector 11 is input to a detector control device 15 and radiation intensity distribution obtained is transmitted to a picture processing device 16. The picture processing device 16 compares the input measured radiation intensity distribution to a preset aimed reference radiation position and reference radiation intensity distribution and calculates the distance Y from the reference radiation position to the center position of the measured radiation intensity distribution and an electron beam deflecting coil control device 17 controls action of an electron beam deflecting coil 16 by which the application position of an electron beam is decided, so that an error signal Y is zero. The radiation position of the electron beam is thus set to the aimed position.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an electron gun-heated steam generator, and in particular, the present invention relates to an electron gun-heated steam generator, and in particular, to a device for generating steam by irradiating an object to be heated, such as a metal, with an electron beam. The present invention relates to an electron gun heated steam generator equipped with a device that can appropriately control the irradiation position, irradiation area shape, and trajectory so that they match the target.

[Conventional technology]

An example of a conventional application of an electron gun heated steam generator is a device described in the 143rd Laser Society Research Report RTM-88-10. The electron gun heated steam generator described in this document is also expected to irradiate the metal to be heated, which is housed in a crucible, with an electron beam and to improve the convergence of the electron beam. Therefore, in order to measure the trajectory and shape of the electron beam, a wire mesh is placed on the electron beam trajectory, and the melting traces of the wire mesh are observed by irradiating the electron beam.

[Problem to be solved by the invention]

Although the conventional electron gun heated steam generator mentioned above attempts to measure the trajectory and shape of the electron beam,
No consideration is given to detecting the irradiation position and the shape of the irradiation area of the electron beam and using this detection data to control the irradiation position and the shape of the irradiation area to suit the target. Therefore, if the irradiation position and the shape of the irradiation area of the electron beam change over time when the electron gun heated steam generator is used for a long period of time, a problem arises in that the steam generation efficiency decreases. Furthermore, if the irradiation position of the electron beam changes significantly, a problem arises in that the crucible is damaged.

An object of the present invention is to have a configuration that can detect and control the irradiation position, irradiation area shape, and trajectory of an electron beam on a heating target, and to detect and control the irradiation position, irradiation area shape, and trajectory of an electron beam on a heating target. It is an object of the present invention to provide an electron gun heated steam generator equipped with a control system that can be adjusted according to the state.

[Means to solve the problem]

A first electron gun-heated steam generator according to the present invention outputs an electron beam from an electron gun, and irradiates the evaporated material with the electron beam by determining the irradiation position of the electron beam with an irradiation position setting means. In an electron gun-heated steam generator for generating steam, a detection means is disposed at a position looking into the irradiation area of the electron beam on the evaporated material, and detects a spatial radiation intensity distribution of X-rays emitted from the evaporated material; an image processing means that has information on a target irradiation position with respect to the electron beam, inputs the detection signal of the detection means, compares it with the target irradiation position, and obtains information on the difference in the irradiation position; A feature of the present invention is that it includes an electron beam irradiation position control means that operates the irradiation position setting means so that the difference in the irradiation positions determined by the image processing means becomes O based on the difference information.

A second electron gun heated steam generator according to the present invention outputs an electron beam from an electron gun, determines the irradiation position of the electron beam by an irradiation position setting means, and determines the shape of an irradiation area by an irradiation area shape setting means. In an electron gun-heated steam generator that generates steam by irradiating an evaporated material with an electron beam, a space where the X-rays emitted from the evaporated material is placed in a position that looks into the electron beam irradiation area of the evaporated material. It has a detection means for detecting the target radiation intensity distribution, information on the target irradiation position and the shape of the irradiation area regarding the electron beam, and inputs the detection signal of the detection means to detect the target irradiation position and the shape of the irradiation area. An image processing means compares and obtains information on the difference in irradiation position and a difference in the shape of the irradiation area, and irradiation is performed so that the difference in irradiation position determined by the image processing means becomes 0゛ based on the information on the difference in irradiation position. Based on the information of the electron beam irradiation position control means that operates the position setting means and the difference in the shape of the irradiation area, the difference in the shape of the irradiation area determined by the image processing means is 0.
A feature of the present invention is that the electron beam irradiation area shape control means is provided for operating the irradiation area shape setting means so that the electron beam irradiation area shape setting means is controlled so that

In the second electron gun heating type steam generator, for example, an electrostatic lens is used as the irradiation area shape setting means.

The third electron gun heated steam generator according to the present invention outputs an electron beam from an electron gun, and determines the irradiation position of the electron beam with an irradiation position setting means (by irradiating the electron beam onto the evaporated material). An electron gun-heated steam generator for generating steam, comprising at least two detection elements disposed at a position looking into the irradiation area of the electron beam on the evaporated material, and a slit member defining the observation area of each detection element. ,
The observation area of each detection element is an X-ray detection means set at a symmetrical position with respect to the target electron beam irradiation position in the direction of controlling the electron beam, and a detection signal of each detection element of the X-ray detection means is input. differential amplification means for obtaining information on fluctuations in the irradiation position of the electron beam from the intensity of the detection signal, and setting the irradiation position so that the fluctuation in the irradiation position determined by the differential amplification means becomes 0 based on the information on the fluctuation in the irradiation position. A feature of the present invention is that it includes an electron beam irradiation position control means for operating the means.

In the first to third electron gun heated steam generators,
Braking X-rays can be used as the X-rays detected by the detection means.

In the fourth electron gun heated steam generator according to the present invention, in the first or second configuration,
Instead of X-rays, the spatial radiation intensity distribution of the X-rays emitted by the steam due to excitation by the electron beam is measured in the electron beam trajectory, and information on the electron beam trajectory is obtained from the measured radiation intensity distribution. The feature is that the trajectory of the electron beam is controlled by a beam irradiation position control means and an irradiation position setting means.

In the first to fourth electron gun heated steam generators,
An electron beam deflector or an electron beam accelerator is used as the irradiation position setting means.

Further, in the first to fourth electron gun heated steam generators, a detection means for detecting light may be used instead of a detection means for detecting X-rays.

[Effect]

In the first electron gun heated steam generator according to the present invention, the detection means detects the spatial radiation intensity distribution of X-rays emitted by the electron beam irradiated onto the surface of the evaporated material, and the image processing means detects the spatial radiation intensity distribution. The electron beam irradiation position control means operates the electron beam irradiation position setting means so that the peak position is compared with a preset target position to find the difference, and the difference becomes 0, and the irradiation position is always set to the target position. Adjust to.

In the second electron gun heated steam generator according to the present invention, the detection means detects the spatial radiation intensity distribution of X-rays emitted by the electron beam irradiated onto the surface of the evaporated material, and the image processing means detects the spatial radiation intensity distribution. The electron beam irradiation position control means controls the electron beam irradiation position setting means to compare each of the peak position and distribution width with a preset target position and target width to determine the difference, and to make each difference zero. The irradiation area shape control means operates the irradiation area shape setting means to constantly adjust the irradiation position of the electron beam and the irradiation area shape on the surface of the evaporated material to a target state.

In the third electron gun heated steam generator according to the present invention, a detection means including at least two detection elements and a differential amplification means are used to detect the deviation of the X-ray radiation intensity distribution with respect to the center position, and The electron beam irradiation position control means operates the electron beam irradiation position setting means so that the irradiation position is always adjusted to the target position.

A fourth electron gun-heated steam generator according to the present invention utilizes the first or second device configuration, and further detects X-rays generated by the collision between the steam and the electron beam in the air. By configuring this, the trajectory of the electron beam is detected and the electron beam is adjusted to the target trajectory.

Each of the above-mentioned electron gun heated steam generators was configured to utilize the spatial radiation intensity distribution of X-rays emitted at or near the surface of the evaporated material, but it is also possible to utilize the light emitted in the same way. It is also possible to configure a signal processing system and a control system using the X-rays, and provide the same control function as when using X-rays.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a first example of an electron gun heated steam generator according to the present invention.
It is a block diagram of an Example. 1 is a metal crucible, shown in longitudinal section. The crucible 1 has an elongated shape in the direction perpendicular to the drawing sheet. In the crucible 1, an evaporated material 2, such as a metal, to be evaporated is heated by an electron beam 3, thereby being accommodated in a partially molten state. The electron beam 3 is normally set to irradiate the center of the evaporated material 2 in the Y direction. The center position of the evaporated material 2 is set as a target position.

4 shows the vapor flow of the evaporated material 2 evaporated by being heated by the electron beam 3. 5 is an electron gun, and the electron gun 5 is disposed close to the crucible 1.

For example, an electron gun 5 having a linear filament is used, and the electron gun 5 is arranged so that the linear filament is parallel to the longitudinal direction of the roof 1. The electron beam output section of the electron gun 1 includes an electron beam deflection coil 6 for determining the irradiation position of the electron beam 3 on the surface of the evaporator 2.
and an electrostatic lens 7 for determining the shape of the electron beam irradiation area on the surface of the evaporated material 2.

A portion around the crucible of the electron gun-heated steam generator having the above configuration is housed in the evaporation chamber 8.

Although the upper part of the evaporation chamber 8 is omitted in the figure, a device for recovering desired components from the vapor flow 4 is usually provided.

A communication section 9 is provided in a part of the side wall of the evaporation chamber 8, and a detector box 10 is provided via this communication section 9. Inside the detector box 10, an X-ray two-dimensional detector 11 is arranged at a predetermined position so as to face the irradiation area of the electron beam 3 on the evaporated material 2. The two-dimensional X-ray detector 11 functions as an X-ray camera, and includes a large number of detection elements.
They are arranged in an array in terms of dimensions, and detect X-rays emitted from a region on the surface of the evaporated material 2 that is irradiated with the electron beam 3. The field of view 14 of the two-dimensional X-ray detector 11 has a pinhole 12 placed in front of it.
determined by. This pinhole 12 determines the area on the surface of the evaporated material 2 that the two-dimensional X-ray detector 11 sees. Further, 13 is a filter, which has the function of setting the wavelength range of X-rays detected by the detector 11 to a predetermined range. The transmission characteristics of the filter 13 can be changed arbitrarily, and in this case, the change is made by selecting a filter with appropriate transmission characteristics.

The detector configuration described above is configured to detect X-rays emitted when the surface of the evaporated material 2 is irradiated with the electron beam 3. The radiation intensity of X-rays generated by electron beam irradiation is proportional to the electron beam intensity. Therefore, by measuring the X-ray radiation intensity distribution around the irradiated portion of the surface of the evaporated material 2, information on the irradiation position of the electron beam 3 and the shape of the irradiation area can be obtained. Note that the emitted X-rays include X-rays generated when the evaporated element is excited by electrons, and bremsstrahlung X-rays generated when the electrons are decelerated on the surface of the evaporated material 2.

Since all of these X-rays are generated in proportion to the intensity of the electron beam 3, the detected emitted X-rays as a whole are proportional to the intensity of the irradiated electron beam. It is also possible to focus only on the braking X-rays, detect them alone, and use them as measurement data for subsequent control.

Further, in the above configuration, an X-ray detector is used as a detector, but the irradiation position and the shape of the irradiation area of the electron beam 3 can be measured using the light generated together with the X-rays when the electron beam 3 is irradiated. is also possible.

A photodetector is used as the detector in this case, but the basic configuration is the same as that of the X-ray detector.

Next, the signal processing system and control system will be explained.

The detection signal output from the two-dimensional X-ray detector 11 is input to the detector control device 15, where the signal is processed and the X-ray radiation intensity distribution in the Y direction is determined. The radiation intensity distribution obtained by the X-ray detector control device 15 is sent to the image processing device 16. The image processing device 16 converts the input measurement radiation intensity distribution into a preset target reference radiation position (usually the center position of the crucible 1 in the Y direction).
and the reference radiant intensity distribution, and calculate the deviation ΔY of the center position of the measured radiant intensity distribution from the reference radiant position and the difference ΔW between the judgment value width of the reference radiant intensity distribution and the judgment value width of the measured radiant intensity distribution as error signals. and output. An error signal ΔY regarding the deviation of the center position of the measured radiation intensity distribution from the reference radiation position is given to the electron beam deflection coil controller 17. Further, ΔW is an error signal related to the difference between the threshold width of the reference radiant intensity distribution and the threshold width of the measured radiant intensity distribution, and is provided to the electrostatic lens control device 18. The electron beam deflection coil control device 17 determines the electron beam irradiation position based on the input error signal ΔY so that the error signal ΔY output from the image processing device 16 becomes 0. Manipulate the behavior of Electrostatic lens control device 18
operates the electrostatic lens 7 that determines the irradiation area of the electron beam, based on the input error signal ΔW, so that the error signal ΔW output from the image processing device becomes O.

Here, control of the irradiation position and the shape of the irradiation area of the electron beam 3 on the surface of the evaporated material 2 will be specifically explained.

To control the irradiation position, first, the image processing device 16 uses the measured X-ray radiation intensity distribution given from the detector control device 15, so that the X-ray intensity distribution 19 reaches a peak as shown in FIG. The position P2 in the Y direction is determined, and the deviation of the target Lupo 1 from the center position P1, that is, the difference in position, is calculated as an error signal ΔY. Next, the electron beam deflection coil control device 17 changes the trajectory of the electron beam 3 by increasing or decreasing the magnetic field generated by the electron beam deflection coil 6 based on the input error signal ΔY, and adjusts the error calculated by the image processing device 16. Control is performed so that the signal ΔY becomes 0.

In addition, the shape of the irradiation area is controlled, and first, the image processing device 16 uses the measured X-ray intensity distribution given from the detector control device 15 in the same way as described above, to form a target irradiation area as shown in FIG. The difference between the judgment value width Wo of 20 and the judgment value width W of the measured X-ray intensity distribution 19 is expressed as an error signal ΔW (='W-W
, ). Next, the electrostatic lens control device 18 controls the electron beam so that the error signal ΔW calculated by the image processing device 16 becomes O by operating the electrostatic lens 7 based on the input error signal ΔW. , the judgment value width W of the irradiation area is the target judgment value width W. make it happen. In this way, the shape of the irradiation area of the electron beam 3 is controlled.

According to the above embodiment, the irradiation position and irradiation area shape of the electron beam 3 on the surface of the evaporated material 2 can be controlled to match a preset target, and the electron beam 3 can be controlled in an optimal state. I can do it.

In particular, regarding the control of the irradiation position of the electron beam, it is also possible to configure the electron beam accelerator in the electron gun control device (not shown) of the electron gun 5 to control the acceleration voltage. In addition, although the configuration of the control device shown in Fig. 1 is configured to control the electron beam irradiation position and irradiation area shape to the target state, it is not necessary to provide two control systems, and the irradiation position can be controlled. It's good to just have a system.

Furthermore, in the description of the device configuration according to the above embodiment, the evaporated material 2
Although the explanation has been made from the viewpoint of controlling the irradiation position and the shape of the irradiation area of the electron beam 3 on the surface of the substrate, according to the control according to the present invention, it is also possible to control the trajectory of the electron beam 3 so that it follows the target trajectory. However, in this case, what is detected by the two-dimensional X-ray detector 11 is not the X-rays emitted on and near the surface of the evaporated substance 2, but the collision between electrons and vapor 4 on the trajectory of the electron beam 3. The image processing device 16 must also be configured to detect and measure the X-rays generated by the electron beam, and the image processing device 16 must also store target reference data for the electron beam.

A second embodiment of the electron gun heated steam generator of the present invention will be described. In FIG. 2, the same elements shown in FIG. 1 are given the same reference numerals. In this embodiment, the configuration of the detector is changed. In the X-ray two-dimensional detector 11 used in the above embodiment, the detection elements were arranged two-dimensionally like an array, whereas in the case of the present embodiment, there are two detection elements 21A, I am using 21B. 22 indicates X at a predetermined expected position on each of the detection elements 21A and 21B.
This is a slit member for inputting a line.

This slit member 22 allows the field of view 2 of the detection element 21A to
3A and the field of view 23B of the detection element 21B are determined. The detection signals output by the detection elements 22A and 22B are processed by the X-ray detector control devices 15A and 15B, respectively, and then input to the differential amplifier 24. X-ray detector control device 15A
, 15B have corresponding detection elements 19A, 19
A signal of the X-ray radiation intensity detected in each field of view 23A, 23B of B can be obtained. The differential amplifier 24 is
The difference between the output signals of the detector control devices 15A and 15B is taken, and this is supplied to the electron beam deflection coil control device 17 as an error signal. Here, the above-mentioned detection elements 21A, 21
If the respective fields of view 23A and 23B of B are set to be symmetrical with respect to the target irradiation position as the center, the above error signal corresponds to the deviation of the irradiation position. Based on this error signal, the electron beam deflection coil control device 17 controls the operation of the electron beam deflection coil 6. The control method is the same as in the first embodiment, and the electron beam deflection coil 6 is operated so that the error signal becomes O. Further, as in the case of the above embodiment, an electron gun control device 25 is provided as shown by the imaginary line in FIG. 2 to control the acceleration voltage of the electron beam accelerator and control the irradiation position of the electron beam. You can also. According to this embodiment, the evaporated material 2
The electron beam irradiation position on the surface of can be controlled to a target position.

Furthermore, in each of the above-described embodiments, the irradiation state of the electron beam is detected based on the spatial radiation intensity distribution of X-rays or light generated on the surface of the evaporator 20 or in the region near the top thereof, and the irradiation state of the electron beam is determined. The configuration was such that at least one of the area shapes was controlled to a target state, but the detection target was X-rays or light generated by the collision between vapor in the air and an electron beam, and the target was set as the target. The electron beam trajectory can also be adjusted by using the electron beam trajectory as reference information.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, in an electron gun-heated steam generator, the spatial radiation intensity distribution of X-rays or light generated from evaporated matter by irradiation with an electron beam is detected, and a target is detected. Information about the electron beam radiation position and radiation area shape is set in advance (by this, the electron beam radiation position and radiation area shape can be matched to the target,
Optimal electron beam irradiation can be achieved. Further, in the electron gun heated steam generator according to the present invention, the trajectory of the electron beam can also be controlled. Furthermore, by using a simple detection element, it is also possible to detect symmetry with respect to the radiation center position and control the radiation position of the electron beam by adjusting to eliminate the bias.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the first embodiment, Fig. 2 is a block diagram showing the second embodiment, Fig. 3 is a graph showing the deviation of the center position of the measured radiation intensity distribution, and Fig. 4 is the measurement 3 is a graph showing the difference between the shape of the radiant intensity distribution obtained and the target shape. [Explanation of symbols] 1... Crucible 2... Evaporated material 3... Electron beam 4... Steam 5... Electron gun 6. ... Electron beam deflection coil 7 ... Electrostatic lens 8 ... Evaporation chamber 10 ... Detector box 11 ... X-ray two-dimensional detector 12 ... Pinholes 15.15A, 15B ... Detector control device 16 ... Image processing device 17 ... Deflection coil control device 18 ... Electrostatic lens control Devices 21A, 21B 2 4 5 Detection element slit member differential amplifier electron gun control device

Claims (9)

[Claims] (1) An electron gun-heated steam generator that outputs an electron beam from an electron gun and determines the irradiation position of the electron beam with an irradiation position setting means to irradiate the evaporated material with the electron beam to generate steam, a detection means disposed at a position looking into the irradiation area of the electron beam on the evaporator and detecting a spatial radiation intensity distribution of X-rays emitted from the evaporator; and information on a target irradiation position with respect to the electron beam. an image processing means that inputs the detection signal of the detection means and compares it with the target irradiation position to obtain information on the difference in the irradiation position; An electron gun-heated steam generator, comprising an electron beam irradiation position control means for operating the irradiation position setting means so that the difference in irradiation positions determined by the processing means becomes zero. (2) An electron beam is output from the electron gun, and the irradiation position of the electron beam is determined by the irradiation position setting means, and the shape of the irradiation area is determined by the irradiation area shape setting means, so that the evaporator is irradiated with the electron beam and vaporized. In the electron gun heated steam generation device that generates a has information on the target irradiation position and irradiation area shape for the electron beam, inputs the detection signal of the detection means, compares it with the target irradiation position and irradiation area shape, and determines the difference in irradiation position. Based on the image processing means for obtaining each piece of information on the difference in the shape of the irradiation area and the information on the difference in the irradiation position, the irradiation position setting means is operated so that the difference in the irradiation position obtained by the image processing means becomes 0. Based on the electron beam irradiation position control means and information on the difference in the shape of the irradiation area,
An electron gun-heated steam generation apparatus comprising: electron beam irradiation area shape control means for operating the irradiation area shape setting means so that the difference in the irradiation area shapes determined by the image processing means becomes zero. (3) The electron gun heated steam generator according to claim 2, wherein the irradiation area shape setting means is an electrostatic lens. (4) An electron gun-heated steam generator that outputs an electron beam from an electron gun and determines the irradiation position of the electron beam with an irradiation position setting means to irradiate the evaporated material with the electron beam to generate steam, At least two detection elements disposed at positions looking into the irradiation area of the electron beam on the evaporated material, and a slit member defining an observation area of each detection element, wherein the observation area of each detection element is An X-ray detection means is set at a symmetrical position with respect to the target electron beam irradiation position in the direction to control the electron beam. differential amplification means for obtaining information on irradiation position fluctuations; and an electron beam for operating the irradiation position setting means so that the irradiation position fluctuations determined by the differential amplification means become zero based on the information on the irradiation position fluctuations. An electron gun heated steam generator characterized by comprising irradiation position control means. (5) In the electron gun heated steam generator according to any one of claims 1, 2, and 4, the X-rays detected by the detection means are braking X-rays. type steam generator. (6) In the electron gun-heated steam generator according to claim 1 or 2, instead of the X-rays emitted from the evaporated material, a space where the steam emits X-rays when excited by the electron beam in the electron beam orbit. measuring the target radiation intensity distribution, obtaining information on the electron beam trajectory from the measured radiation intensity distribution, and controlling the electron beam trajectory by the image processing means, the electron beam irradiation position control means, and the irradiation position setting means. An electron gun heated steam generator characterized by: (7) The electron gun heated steam generator according to any one of claims 1, 2, 4, and 6, wherein the irradiation position setting means is an electron beam deflection device. Steam generator. (8) The electron gun heated steam generator according to any one of claims 1, 2, 4, and 6, wherein the irradiation position setting means is an electron beam accelerator. Steam generator. (9) The electron gun heated steam generator according to any one of claims 1 to 8, characterized in that a detection means for detecting light is used in place of the detection means for detecting the X-rays. Gun-heated steam generator.