JP2003188447A - Diffraction grating exchange type electromagnetic wave generator, diffraction grating position adjusting method and apparatus thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To exchange the other diffraction grating without breaking a vacuum after an electromagnetic wave generating state is adjusted using a reference diffraction grating within a vacuum chamber. <P>SOLUTION: The diffraction grating exchange type electromagnetic wave generator, a diffraction grating position adjusting method and its apparatus are configured so that the other diffraction gratings (4, 4b and 4c) are exchanged without breaking a vacuum after a position is adjusted with the reference diffraction grating (4a) within the vacuum chamber (1), and the position is adjusted by detecting electromagnetic waves (11) from minute domains of both ends (P1, P2) of the reference diffraction grating (4a) using a pair of light receiving elements (21, 21a). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diffraction grating exchange type electromagnetic wave generating apparatus and a diffraction grating position adjusting method and apparatus, and more particularly, to a plurality of diffraction gratings that can be moved in a vacuum chamber without breaking the vacuum. A diffraction grating suitable for the purpose can be selected, and the relative position of the electron beam and the reference diffraction grating is adjusted by measuring the intensity of the electromagnetic wave from the reference diffraction grating in each diffraction grating with a pair of light receiving elements. The present invention relates to a new improvement for eliminating the need for readjustment of position for replacement of each diffraction grating.

[0002]

2. Description of the Related Art As an electromagnetic wave generator using a diffraction grating of this type that has been conventionally used, the configuration shown in FIGS. 4 to 5 has been adopted. That is, in the case of the configuration of FIG. 4, the vacuum chamber 1 is provided with the electron gun 2 and the diffraction grating drive shaft 3 at positions orthogonal to each other, and the diffraction grating drive shaft 3 is provided with the diffraction grating 4 so as to be rotatable. Has been. An electron beam 5 from the electron gun 2 enters a diffraction grating 4 and an ammeter 6 is connected to the diffraction grating 4.
Therefore, the positional relationship between the diffraction grating 4 and the electron beam 5 is measured by measuring the current flowing in the diffraction grating 4,
If necessary, the high vacuum was broken and replaced with another diffraction grating 4.

In the case of the other conventional example shown in FIGS. 5 and 6, the structure is the same as that of FIG. 4, and therefore the same parts are denoted by the same reference numerals and the description thereof is omitted, but the vacuum chamber 1
The visible portion as a laser beam, which is the electromagnetic wave 11 radiated by the interaction with the electron beam 5, is visually determined by the visual observation unit 10 provided in the electron beam 5 and the diffraction grating 4 to be confirmed. Relative positioning was performed. Therefore, in FIG. 4, the diffraction grating 4 corresponding to the target wavelength is
Is moved to a position where the electron beam 5 hits, and while the electron beam current value is measured by the ammeter 6, the adjustment is completed by moving the diffraction grating 4 to a position where the current value becomes 0 amperes. Alternatively, the same adjustment is performed by moving the electron gun 2 instead of moving the diffraction grating 4. In FIG.
It is an electromagnetic wave generated on the diffraction grating 4 due to the interaction with the electron beam 5. The position of the diffraction grating 4 and the electron beam 5 is adjusted while visually confirming visible light.

[0004]

Since the conventional electromagnetic wave generator using the diffraction grating is constructed as described above, there are the following problems. That is, once the irradiation of the electron beam emitted from the electron gun is stopped and the vacuum in the vacuum chamber is broken, the reproducibility of the beam trajectory is not guaranteed before and after the vacuum is stopped. There is a drawback that even if the diffraction grating is brought to a position, there is no guarantee that the positional relationship between the electron beam and the diffraction grating is properly maintained. Therefore, in order to obtain an electromagnetic wave having a target wavelength, the conventional device is configured to be appropriately replaced with a corresponding diffraction grating, and therefore it is necessary to break the vacuum each time, and the electron beam irradiation is not performed. It took a long time to reach the ultra-high vacuum state that would be possible again. or,
Each time the diffraction grating was replaced, it was necessary to adjust the positions of the electron beam and the diffraction grating. In the measurement of the current value flowing through the diffraction grating, which is one of the position adjusting methods therefor, the parallelism between the diffraction grating and the electron beam cannot be measured. Another position adjustment method, interaction with the electron beam,
In the visual measurement of visible light, which is an electromagnetic wave generated in the diffraction grating, it takes a long time to determine, and the emission intensity thereof cannot be measured.

The present invention has been made to solve the above problems, and in particular, by moving a plurality of diffraction gratings in a vacuum chamber, a diffraction grating suitable for the purpose can be selected without breaking the vacuum. It is possible to adjust the relative position of the electron beam and the reference diffraction grating by measuring the intensity of the electromagnetic wave from the reference diffraction grating in each diffraction grating with a pair of light receiving elements, and to replace other diffraction gratings. It is an object of the present invention to provide a diffraction grating exchange type electromagnetic wave generator which does not require readjustment of position, and a diffraction grating position adjusting method and device.

[0006]

A diffraction grating exchange type electromagnetic wave generator according to the present invention is an electromagnetic wave generator for generating an electromagnetic wave of an arbitrary wavelength by the interaction between an electron beam and a diffraction grating in a vacuum chamber. In the above, by using a plurality of the diffraction gratings and rotating or linearly moving each of the diffraction gratings, a diffraction grating corresponding to the target electromagnetic wave is applied to the electron beam without breaking the vacuum in the vacuum chamber. The diffraction grating is installed at a predetermined position, and each diffraction grating is provided at a predetermined rotation angle at an outer peripheral position of a diffraction grating drive shaft provided in the vacuum chamber, and each diffraction grating is provided. The electromagnetic wave from the reference diffraction grating in FIG. 2 is received by at least two light receiving elements and the reference value is detected. Method, is incident electron beam to the reference grating of a plurality of diffraction gratings in a vacuum chamber,
A method of adjusting the relative positions of the electron beam and the diffraction grating by detecting the electromagnetic waves generated from two minute areas on the surface of the electromagnetic waves generated on the surface of the diffraction grating and measuring the radiation intensity thereof. Further, the diffraction grating position adjusting device according to the present invention makes an electron beam incident on a reference diffraction grating of a plurality of diffraction gratings in a vacuum chamber, and performs relative position adjustment of the electron beam and the reference diffraction grating. In the diffraction grating position adjusting device configured as described above, at least a pair of light receiving elements that are provided in the vacuum chamber and that are opposed to both ends of the reference diffraction grating and are spaced apart from each other, and are provided between each of the light receiving elements and the diffraction grating. Among the electromagnetic waves generated on the surface of the diffraction grating, the electromagnetic waves generated from two minute regions on the surface are described above. The radiation intensity measured by the light receiving element by directing through the capillary, which is configured to perform the relative positioning of the electron beam and the reference grating.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described with reference to the drawings.
Folded grating exchange type electromagnetic wave generator and diffraction grating position adjustment method
A preferred embodiment of the method and apparatus will be described.
It should be noted that the same or equivalent parts as those of the conventional example are designated by the same reference numerals.
Reveal What is designated by reference numeral 1 in FIGS. 1 to 3
Has a box shape as a whole, 10 ^-9Vacuum higher than Torr
One side of this vacuum chamber 1.
1a is provided with an electron gun 2 for emitting an electron beam 5
There is.

As shown in FIG. 2, a diffraction grating drive shaft 3 driven by a motor or the like is provided on the other surface 1b orthogonal to the one surface 1a of the vacuum chamber 1. The axial directions of the electron beams 5 are configured to be orthogonal or substantially orthogonal to each other. It should be noted that this diffraction grating drive shaft 3 is used for each diffraction grating 4, 4a, 4
rotation exchange movement of b and 4c and rotation gratings 4, 4a and 4b,
4c itself is constituted by a multi-axis mechanism (not shown) having two roles of fine adjustment. In addition, the axial direction may be substantially orthogonal to a slight deviation from the perfect orthogonal due to fine adjustment of the positions of the rotating gratings 4, 4a, 4b and 4c and the electron beam 5.

The diffraction grating mounting base 20 provided on the diffraction grating drive shaft 3 and having a cross shape as a whole has a total of four diffraction gratings 4 and 4a at positions different in 90 degree rotation angle.
4b and 4c are provided, of which diffraction gratings 4, 4b and 4c corresponding to electromagnetic waves having mutually different target wavelengths are provided, except for the reference diffraction grating 4a. Therefore, in the state of FIG. 1, the state where the diffraction grating mounting base 20 is positioned at a position where the electron beam 5 is incident on the reference diffraction grating 4a is shown.

As shown in FIGS. 2 and 3, at least a pair of light receiving elements 21 and 21a (a pair or more is also possible) on the facing surface 1c along the axial direction of the diffraction grating drive shaft 3 is the reference diffraction grating. 4a and 4a are spaced apart from each other. Each of the light receiving elements 21 and 21a is located on the facing surface 1c of the vacuum chamber 1, and each of the light receiving elements 21 and 21a.
A pair of thin tubes 22, 22a corresponding to a and having a cavity structure inside the vacuum chamber 1 having a cavity structure through which the electromagnetic waves generated from the reference diffraction grating 4a can be transmitted and propagated like a known waveguide. And each of these thin tubes 22 and 22a is arranged so as to correspond to both ends P1 and P2 of one of the diffraction gratings 4 to 4c positioned at the position where the electron beam 5 is incident. .

Therefore, the thin tubes 22 and 22a are arranged at both ends P1 and P2 of the diffraction gratings 4 to 4c with a distance D enough for the electron beam 5 to pass therethrough, and the light receiving elements 21 and 21a on the opposite side thereof. By arranging the above, only the electromagnetic wave 11 radiated from the extremely small area of the reference diffraction grating 4a at both ends P1 and P2 is detected, and the reference values are simultaneously detected by the light receiving elements 21 and 21a from both ends. Thus, the parallelism between the diffraction gratings 4 to 4c and the electron beam 5 when exchanged can be adjusted, and the distance D relationship between the reference diffraction grating 4a and the electron beam 5 can be adjusted by measuring the intensity of the detected electromagnetic wave. Becomes In addition, at the time of this adjustment, it is not necessary to break the vacuum to stop the electron beam 5, so once the positional relationship between the reference diffraction grating 4a and the electron beam 5 is adjusted, other adjustments are not made. It becomes easy to switch to the target wavelength by replacing the diffraction gratings 4, 4b, and 4c. In the above-mentioned configuration, the case where the diffraction gratings 4, 4b and 4c are rotated and moved and replaced is described, but it is also possible to select not only by rotation but also by linear movement. .

Next, the operation will be described. First, the diffraction gratings 4, 4b, 4c configured to emit electromagnetic waves having a target wavelength are installed at positions other than the reference diffraction grating 4a. In the above-mentioned state, first, the reference diffraction grating 4a
Are brought to a position intersecting with the electron beam 5. Next, the electron beam 2 is emitted from the electron gun 2 and the reference diffraction grating 4a is moved to an appropriate position, or the electron gun 2 is moved,
When the electron beam trajectory is corrected, the interaction between the electron beam 5 and the diffraction grating 4a causes the emission of visible light to change to the diffraction grating 4a.
The position that can be confirmed on a can be obtained. Here, by appropriately selecting the relative position between the electron beam 5 and the reference diffraction grating 4a, the wavelength of the electromagnetic wave 11 emitted from the diffraction grating 4a can be selected in the visible light region. Next, the emitted visible light propagates through the thin tubes 22 and 22a, and the light receiving element 2
The detection and the intensity measurement are performed by 1, 21a. At this time, if visible light of the same intensity is detected by the two light receiving elements 21 and 21a at the same time, it means that visible light of the same intensity is emitted from both ends of the reference diffraction grating 4a, and the electron beam 5 is the reference light. This means that accurate parallelism is maintained with respect to the diffraction grating 4a. When the position adjustment of the reference diffraction grating 4a and the electron beam 5 is completed in this way, the other diffraction gratings 4, 4b, 4c for the target wavelength are rotationally moved to the reference diffraction grating 4a position described above, The target electromagnetic wave can be obtained. The aforementioned diffraction gratings 4, 4b, 4
Since it is not necessary to stop the electron beam 5 in the operation of switching and selecting c, readjustment is basically unnecessary. Therefore, the mechanical movement of the diffraction gratings 4, 4b, 4c is performed by the motor, and the two light receiving elements 21, 21a are set to O at a certain threshold value.
It is possible to automatically adjust the positions of the other diffraction gratings 4, 4b, 4c and the electron beam 5 by automatically controlling the movement to the N position. In the case described above, the electromagnetic wave 11 emitted from the reference diffraction grating 4a is received by the light receiving element 21,
Since it is detected by 21a, it is possible to perform digital processing as on / off by numerically measuring the radiation intensity, improve positioning accuracy, and perform automatic positioning control. ) It is also possible to obtain an automatic start-up mechanism for the generator.

[0013]

Since the diffraction grating exchange type electromagnetic wave generator and the diffraction grating position adjusting method and apparatus according to the present invention are configured as described above, the following effects can be obtained. That is, by installing a plurality of diffraction gratings capable of generating electromagnetic waves of a target wavelength in a vacuum from the beginning, without breaking the vacuum,
It is possible to replace the diffraction grating. Some vacuums require a vacuum higher than 10 ^-9 Torr depending on the type of electron gun used. In that case, even if the vacuum container is burned out to reach the vacuum state, Although it may require one day or more, there is no need to break the vacuum when exchanging the diffraction grating, which makes it possible to continuously obtain electromagnetic waves having different wavelengths. Further, in order to obtain the optimum positional relationship between the diffraction grating and the electron beam, two light receiving elements are used to detect the electromagnetic waves radiated from both ends of the diffraction grating at the same time and their intensities. By improving the reproducibility of the optimum positional relationship between the two in adjusting the position with the beam, and by using digital processing to turn on / off the detection of electromagnetic waves and to turn on / off whether or not it is above the reference value by intensity measurement, Therefore, it is possible to construct an automatic exchange mechanism for the diffraction grating and an automatic optimum positioning mechanism for the diffraction grating and the electron beam.

[Brief description of drawings]

FIG. 1 is a front view showing a diffraction grating exchange type electromagnetic wave generating device, a diffraction grating position adjusting method and a device according to the present invention.

FIG. 2 is a right side view of FIG.

FIG. 3 is a plan view of FIG.

FIG. 4 is a configuration diagram showing an electromagnetic wave generator using a conventional diffraction grating.

5 is a configuration diagram showing another conventional form of FIG.

FIG. 6 is an enlarged view showing part A of FIG.

[Explanation of symbols]

1 vacuum chamber 2 electron gun 3 Diffraction grating drive axis 4, 4b, 4c diffraction grating 4a Reference diffraction grating 5 electron beam Both ends of P1 and P2 11 electromagnetic waves 20 Diffraction grating mount

Continued front page    (72) Inventor Takeshi Iida             2-2-1 Fukuura, Kanazawa-ku, Yokohama-shi, Kanagawa               Japan Steel Works, Ltd. F-term (reference) 2H049 AA02 AA50 AA55 AA62 AA68                       AA69                 5F072 AC10 KK07 KK30

Claims (4)

[Claims] 1. An electromagnetic wave generator for generating an electromagnetic wave (11) of an arbitrary wavelength by interaction between an electron beam (5) and a diffraction grating (4-4c) in a vacuum chamber (1), Using a plurality of the diffraction grating (4-4c), by rotating or linearly moving each of the diffraction grating (4-4c), the diffraction grating (4-4c) corresponding to the target electromagnetic wave, the vacuum chamber (1) The electron beam without breaking the vacuum inside
A diffraction grating exchange type electromagnetic wave generator characterized in that it is arranged at a predetermined position with respect to (5). 2. Each of the diffraction gratings (4-4c) is provided at a predetermined rotation angle at an outer peripheral position of a diffraction grating drive shaft (3) provided in the vacuum chamber (1), and each diffraction grating (4-4c) is provided. lattice
The electromagnetic wave (11) from the reference diffraction grating (4a) in (4 to 4c) is received by at least two light receiving elements (21, 21a) to detect the reference value. Diffractive grating exchange type electromagnetic wave generator. 3. A surface of the diffraction grating (4-4c), wherein an electron beam (5) is made incident on a reference diffraction grating (4a) among a plurality of diffraction gratings (4-4c) in a vacuum chamber (1). Of the electromagnetic waves generated on the surface, the electromagnetic waves generated from the two minute areas on the surface
A diffraction grating position adjusting method characterized in that the relative position of the electron beam (5) and the diffraction grating (4-4c) is adjusted by detecting (11) and measuring the radiation intensity thereof. 4. An electron beam (5) is made incident on a reference diffraction grating (4a) among a plurality of diffraction gratings (4-4c) in a vacuum chamber (1) to obtain the electron beam (5) and the reference diffraction grating. (4a) in a diffraction grating position adjusting device for performing relative position adjustment, facing the both ends (P1, P2) of the reference diffraction grating (4a) provided in the vacuum chamber (1) and separated from each other. At least a pair of light receiving elements (21, 21a), and a pair of thin tubes (22, 22a) provided between each of the light receiving elements (21, 21a) and the diffraction gratings (4 to 4c) and separated from each other. Of the electromagnetic waves (11) generated on the surface of the diffraction grating (4 to 4c), the electromagnetic waves (11) generated from two minute areas on the surface are guided through the thin tubes (22, 22a). Each light receiving element (21, 21
A diffraction grating position adjusting device, characterized in that the radiation intensity is measured in a) and the relative position of the electron beam (5) and the reference diffraction grating (4a) is adjusted.