JP5737749B2 - Photon beam scanning apparatus and photon beam scanning method - Google Patents

Description

  The present invention relates to a photon beam scanning apparatus and a photon beam scanning method.

By making the high-energy electron beam generated by the accelerator collide with the laser beam, γ-rays (photon beams) due to laser Compton scattering can be generated, and the generated quasi-monochromatic γ-rays are generated by, for example, cargo containers. This is useful for nondestructive inspection of the inside (containment) of such a large article.
When performing such a nondestructive inspection, in order to scan the entire object to be inspected, it is necessary to scan while changing the positional relationship between the γ-ray source and the object.

  As an apparatus for performing the scanning as described above, for example, there is one described in Patent Document 1. This scanning device controls a beam incident angle control device that changes an incident angle of an electron beam incident on a collision point, a laser incident angle control device that changes an incident angle of a laser beam incident on a collision point, and controls these devices. And a control device. In laser Compton scattering, a photon beam is emitted in the same direction as the incident direction of the electron beam to the collision point. Therefore, according to the scanning device, it is generated by changing the incident angle of the electron beam to the collision point. The radiation direction of the photon beam to be changed can be changed. This makes it possible to scan the object over a predetermined range.

JP 2009-187725 A (see FIG. 2)

According to the scanning device described in Patent Document 1, a frontal collision occurs between an electron beam and a laser beam by controlling the incident angle of the laser beam to the collision point according to the incident angle of the electron beam to the collision point. Can be made.
However, even if the incident angle of the electron beam to the collision point is changed for the purpose of scanning the object over a predetermined range, the laser beam is actually collided with the electron beam at the collision point. It is difficult. That is, if a plane mirror is used as in Patent Document 1, it is possible to change the path of the laser beam, but in order to make the laser beam reflected by the plane mirror enter the original collision point, for example, Complex control is required.

  It is an object of the present invention to provide a photon beam scanning apparatus and a photon beam scanning method that can easily realize a collision between an electron beam and a laser beam.

(1) A photon beam scanning apparatus of the present invention includes an electron beam generating apparatus that generates an electron beam, a laser generating apparatus that generates laser light, and an electron beam that controls the generated electron beam and the path of the laser light. A path control device for causing the laser beam to collide, and the path control device controls the path of the electron beam to cause the electron beam to be incident on a first focal point of an ellipse virtually set. An electron beam control unit that changes an incident angle to one focal point; a laser light control unit that changes a traveling direction of the laser beam from a second focal point of the ellipse toward a part of the ellipse; and the one of the ellipses. has a reflective surface along the section, and an ellipsoidal mirror for incident from said second focal point by reflecting laser light incident on the reflective surface to the first focal point from the opposite side of the electron beam, the The laser light control unit has a parabolic mirror that has a reflecting surface along a part of a parabola with the second focal point as a focal point and reflects the laser light so as to pass through the second focal point. Yes .

According to the present invention, the electron beam control unit controls the electron beam path to cause the electron beam to enter the first elliptical focal point set virtually. In addition, the laser beam incident on the reflecting surface is reflected from the second focal point of the ellipse by the ellipsoidal mirror having the reflecting surface along a part of the ellipse, so that the laser beam is reflected from the opposite side of the electron beam. Incident to the first focal point. As a result, the laser beam and the electron beam collide at the first focal point to generate a photon beam.
Then, when the electron beam control unit changes the incident angle of the electron beam to the first focal point in order to change the generation direction of the photon beam, the laser light control unit changes the elliptical shape from the second focal point accordingly. What is necessary is just to change the advancing direction of the laser beam which goes to a part of (the reflective surface of an ellipsoidal mirror). That is, even if the traveling direction of the laser beam from the second focal point to the reflecting surface of the ellipsoidal mirror is changed, the laser beam reflected by the ellipsoidal mirror is always incident on the first focal point and is reflected by the ellipsoidal mirror. By changing the traveling direction of the laser beam to the surface, the incident angle of the laser beam reflected by the ellipsoidal mirror to the first focal point can be changed. For this reason, even when the generation direction of the photon beam is changed, the collision between the electron beam and the laser beam can be easily realized.

In addition, the laser light control unit has a parabolic mirror that has a reflecting surface along a part of a parabola with the second focal point as a focal point and reflects the laser light so as to pass through the second focal point. doing.
For this reason, if the generated laser light is incident on the reflecting surface of the parabolic mirror, the reflected laser light can pass through the second focal point. Therefore, by changing the incident point of the laser beam incident on the reflecting surface of the parabolic mirror, the traveling direction of the laser beam that passes through the second focal point and travels toward the reflecting surface of the ellipsoidal mirror along a part of the ellipse Can be changed. As a result, the incident angle of the laser beam reflected by the ellipsoidal mirror to the first focal point can be changed.

( 2 ) Further, the present invention is a photon beam scanning method for controlling a path of an electron beam and a laser beam to collide the electron beam and the laser beam to generate a photon beam, wherein the path of the electron beam is performed. An electron beam control step for changing the incident angle of the electron beam to the first focal point of the ellipse set by controlling the reflection point, and a reflecting surface along a part of the parabola focusing on the second focal point of the ellipse The laser beam is incident on a parabolic mirror having the above, the laser beam reflected by the parabolic mirror is allowed to pass through the second focal point, and the incident point of the laser beam on the parabolic mirror is changed. Accordingly, from the second focal point, and characterized by comprising a laser beam control step of changing the traveling direction of the laser beam towards the ellipsoidal mirror having a reflecting surface along a portion of the ellipse That.

  According to the present invention, in order to change the generation direction of the photon beam, the incident angle of the electron beam to the first focal point may be changed (electron beam control step). What is necessary is just to change the advancing direction of the laser beam which goes to the ellipsoidal mirror which has a reflective surface along a part of ellipse from (laser beam control step). That is, in the laser light control step, even if the traveling direction of the laser light from the second focal point to the reflecting surface of the elliptical mirror is changed, the laser light reflected by the elliptical mirror is always incident on the first focal point, By changing the traveling direction of the laser beam to the reflecting surface of the ellipsoidal mirror, the incident angle of the laser beam reflected by the ellipsoidal mirror to the first focal point can be changed. For this reason, even when the generation direction of the photon beam is changed, the collision between the electron beam and the laser beam can be easily realized.

  According to the present invention, in response to changing the incident angle of the electron beam to the first focal point of the ellipse, the laser beam traveling from the second focal point to the elliptical mirror having a reflecting surface along a part of the ellipse. If the traveling direction is changed, the laser beam reflected by the ellipsoidal mirror can be incident on the first focal point while changing the incident angle. For this reason, even when the generation direction of the photon beam is changed, the collision between the electron beam and the laser beam can be easily realized.

It is the schematic block diagram which looked at the photon beam scanning apparatus of this invention planarly. It is explanatory drawing explaining the function of the route control apparatus of FIG. It is explanatory drawing explaining the function of the route control apparatus of FIG. It is the schematic block diagram which looked at other embodiment of the photon beam scanning apparatus of this invention planarly. It is explanatory drawing explaining the function of the route control apparatus of FIG. It is explanatory drawing explaining the function of the route control apparatus of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of the photon beam scanning apparatus according to the present invention viewed in a plan view. In the present embodiment, a photon beam scanning device (hereinafter referred to as a scanning device) is used as an inspection device that performs nondestructive inspection inside a large article (hereinafter referred to as a scanning object 13) such as a cargo container. The case where it applies is demonstrated.
This scanning apparatus includes an electron beam generator 1 that generates an electron beam E, a laser generator 2 that generates a laser beam R, a path (orbit) of the generated electron beam E, and a path of the generated laser beam R. A path control device 3 for controlling the (orbit) and causing the electron beam E and the laser beam R to collide at a predetermined collision point is provided. In this scanning device, the electron beam E and the laser beam R collide with each other to generate a photon beam by Compton scattering. In the present embodiment, a photon beam to be generated will be described as γ rays.

  The electron beam generator 1 includes an electron gun 1a that generates an electron beam E, and a linear accelerator tube 1b that accelerates the generated electron beam E to high energy. To enter. Further, the scanning device has an electron beam dump 31 and supplements the electron beam E emitted from the vacuum vessel 20.

  The laser generator 2 generates a laser beam R and causes the generated laser beam R to enter a movable mirror 16 described later. In a second embodiment (FIG. 4) described later, the light is incident on the plane mirror 43. As the laser generator 2 and the electron beam generator 1, those conventionally known can be adopted.

  Each device included in the scanning device of the present invention and the arrangement of the collision points are based on a virtually set ellipse 10. In the present embodiment, the ellipse 10 is set on a horizontal plane. The ellipse 10 is a curve formed from a set of points at which the sum of the distances from the first focus 11 and the second focus 12 is constant, and the first focus 11 is a collision point. Each device and its function will be described below.

  In FIG. 1, the path control device 3 includes an electron beam control unit 7 that controls the path of the generated electron beam E, a laser beam control unit 8 that controls the path of the generated laser beam E, and a part of the ellipse 10. And an ellipsoidal mirror 9 having a reflecting surface 19 provided along the surface. The path control device 3 further includes a control main unit (computer) 15 that controls the electron beam control unit 7 (function) and the laser light control unit 8 (function).

The electron beam control unit 7 includes a vacuum container 20, a first deflection magnet 21 and a second deflection magnet 22 for incident deflection, and a third deflection magnet 23 and a fourth deflection magnet 24 for exit deflection. . Each of the first to fourth deflecting magnets 21 to 24 can bend the path of the electron beam E by a magnetic field.
Further, the control main body device 15 changes (adjusts) the degree of bending of the electron beam E by controlling the outputs of the deflecting magnets 21 to 24, and changes the incident angle of the electron beam E to the first focal point 11. Can be changed. Even if the incident angle is changed, the electron beam E is controlled so as to pass through the first focal point 11 without fail.

2 and 3 are explanatory diagrams for explaining the function of the path control device 3. As shown in FIG. 2, the incident angle of the electron beam E to the first focal point 11 is θ1, but by decreasing the deflection angle of the electron beam E in each of the deflecting magnets 21 to 24, as shown in FIG. The incident angle can be changed to θ2. The incident angles θ1 and θ2 at the first focal point 11 are based on a straight line A connecting the first focal point 11 and the center 13a of the scanning target 13.
As described above, the electron beam control unit 7 controls the path of the electron beam E so that the electron beam E is incident on the first focal point 11 of the ellipse 10 and the incident angle on the first focal point 11 is changed. In the vacuum container 20, an electron beam E having a path that always passes through the first focal point 11 of the ellipse 10 can be obtained.

  Further, the control main unit 15 controls the first deflection magnet 21 and the fourth deflection magnet 24 in association with each other, that is, gives the same characteristics to the first deflection magnet 21 and the fourth deflection magnet 24 from the same drive source. The first deflecting magnet 21 and the fourth deflecting magnet 24 have the same angle for deflecting the electron beam E, but the deflecting directions are opposite. Similarly, the angle at which the electron beam E is deflected is the same between the second deflecting magnet 22 and the third deflecting magnet 23, but the deflecting direction is opposite. Thereby, it is possible to set the incident and emission of the electron beam E in the vacuum vessel 20 as fixed points. The direction of deflection is based on the traveling direction of the electron beam E traveling from the incident side to the exit side of the vacuum vessel 20.

As shown in FIG. 1, the ellipsoidal mirror 9 is a fixed reflecting mirror, and the reflecting surface 19 is provided along a part of the ellipse 10. That is, the reflection surface 19 does not need to be provided on the entire circumference of the ellipse 10, and may be only a part, and is composed of an ellipsoid including a part (arc) of the ellipse 10. The laser beam R generated by the laser generator 2 enters the ellipsoidal mirror 9 through the second focal point 12 of the ellipse 10.
Since the reflecting surface 19 of the ellipsoidal mirror 9 is provided along a part of the ellipse 10, when the laser light R incident on the reflecting surface 19 from the second focal point 12 is reflected by the reflecting surface 19, The incident light can enter the first focal point 11 from the side opposite to the incident direction of the electron beam E. This utilizes the characteristic that light emitted from one focal point of the ellipse and reflected by a mirror on the ellipse reaches the other focal point of the ellipse.
The laser beam R is incident on the first focal point 11 from the side opposite to the incident direction of the electron beam E, so that the first focal point 11 can be a collision point between the laser beam R and the electron beam E. Generates gamma rays due to Compton scattering.

  The laser light control unit 8 has a function of changing the traveling direction of the laser light R from the second focal point 12 of the ellipse 10 toward a part of the ellipse 10. Specifically, as shown in FIG. 2, the ellipsoidal mirror 9 is installed on a part of the ellipse 10 to which the laser beam R from the second focal point 12 is directed as described above. The laser light control unit 8 of the present embodiment has a movable mirror 16, which reflects the laser light R incident on the second focal point 12 at the second focal point 12, and The reflection direction can be changed. The movable mirror 16 has a reflection point 16 a at the second focal point 12 and is a rotating mirror that rotates around the center line C passing through the second focal point 12. The center line C is a line orthogonal to the plane including the ellipse 10 and is a vertical line passing through the second focal point 12 in this embodiment. The reflection point 16a is a point on the reflection surface 16b of the movable mirror 16. The reflection surface 16b of the movable mirror 16 is a flat surface, and the incident angle and the emission angle of the laser light R are the same with respect to the reflection surface 16b. It becomes.

  The laser light control unit 8 has a drive unit (not shown) that rotates the ellipsoidal mirror 9 forward and backward around the center line C. The drive unit includes, for example, a motor with a speed reducer, and the control main body device 15 controls the rotational speed of the motor to adjust the rotational position (rotation angle) around the center line C of the movable mirror 16. Can do.

As shown in FIG. 2, the laser beam R generated by the laser generator 2 is incident on the reflecting surface 16 b of the movable mirror 16, and the reflected laser beam R is incident on the reflecting surface 19 of the elliptical mirror 9. The path of the laser beam R incident on the ellipsoidal mirror 9 from the second focal point 12 is V1.
Since the laser beam R generated by the laser generator 2 is incident on the second focal point 12 through a constant linear path, when the ellipsoidal mirror 9 is rotated by a predetermined angle by the drive unit, as shown in FIG. The incident angle of the laser beam R at the reflection point 16a of the movable mirror 16 changes compared to the case of FIG. 2, and the reflection angle also changes accordingly, and enters the ellipsoidal mirror 9 from the second focal point 12. The path of the laser beam R is V2.

As described above, the laser light control unit 8 can change the traveling direction of the laser light R from the second focal point 12 of the ellipse 10 toward the ellipsoidal mirror 9 between V1 and V2.
Therefore, if the generated laser beam R is incident on the second focal point 12, the moving direction of the laser beam R toward the ellipsoidal mirror 9 can be changed by changing the reflection direction by the movable mirror 16. As a result, the incident angle of the laser beam R reflected by the ellipsoidal mirror 9 to the first focal point 11 can be changed according to (according to) the incident angle of the electron beam E.

  A photon beam (γ ray) scanning method performed by the scanning device of this embodiment will be described. In this scanning method, the paths of the electron beam E and the laser beam R are controlled to cause the electron beam E and the laser beam R to collide with each other at the first focal point 11 of the ellipse 10 as a collision point, thereby generating γ rays. This is a method of performing γ-ray scanning on the scanning object 13.

As shown in FIG. 2, when the γ-ray emission direction is K1, the electron beam control unit 7 causes the electron beam E to enter the first focal point 11 of the ellipse 10 at an incident angle θ1. Then, the movable mirror 16 is controlled to be at a predetermined rotational position, and the traveling direction of the laser light R reflected by the movable mirror 16 is set to V1.
When the laser beam R is reflected by the ellipsoidal mirror 9, the laser beam R enters the first focal point 11 at an incident angle θ11. The incident angles of the electron beam E and the laser beam R at the first focal point 11 are the same at the opposing angles (θ1 = θ11), whereby the electron beam E and the laser beam R collide head-on, and the electron beam E Gamma rays can be emitted on an extension line in the incident direction, that is, with the radiation direction as K1. One side of the scanning target 13 in the left-right direction is located at the destination of the γ rays.

  Then, in order to scan toward the other side of the inspection target 13 in the left-right direction, the electron beam controller 7 controls the path of the electron beam E as shown in FIG. The incident angle to the focal point 11 is changed from θ1 to θ2 (electron beam control step). Following this change (in synchronization with this change), the traveling direction (path) of the laser light R from the second focal point 12 of the ellipse 10 toward the ellipsoidal mirror 9 is changed from V1 to V2 ( Laser light control step). That is, in the laser light control step of this embodiment, the rotational position of the movable mirror 16 provided at the second focal point 12 is changed.

  When the laser beam R whose traveling direction is V2 is reflected by the ellipsoidal mirror 9, the laser beam R enters the first focal point 11 at an incident angle θ12. The incident angles of the electron beam E and the laser beam R at the first focal point 11 are the same at the opposing angles (θ2 = θ12), whereby the electron beam E and the laser beam R collide head-on, and the electron beam E Gamma rays can be emitted on an extension line in the incident direction, that is, with the radiation direction as K2. The other side in the left-right direction of the scanning object 13 is located at the destination of the γ rays.

  Thus, in the laser beam control step, even if the incident angle of the electron beam E to the first focal point 11 is changed from θ1 to θ2, the laser beam R incident from the second focal point 12 and reflected by the ellipsoidal mirror 9 is , The light always enters the first focal point 11. In addition, the laser beam R can be incident on the first focal point 11 so that the incident angle θ12 is a frontal collision with the electron beam E whose incident angle has changed from θ1 to θ2. As described above, this is due to the characteristic of the characteristic ellipsoidal mirror that light emitted from one focal point of the ellipse and reflected by the mirror on the ellipse reaches the other focal point of the ellipse.

  Therefore, in order to change the radiation direction of γ-rays, the incident angle of the electron beam E to the first focal point 11 may be changed between θ1 and θ2, and according to this, as described above, What is necessary is just to change the advancing direction of the laser beam R which goes to the ellipsoidal mirror 9 from the 2nd focus 12 between V1 and V2. As described above, according to the scanning device of the present embodiment, it is possible to easily realize a frontal collision between the electron beam E and the laser light R even when the radiation direction of γ rays is changed.

  In the present embodiment, the laser light control unit 8 has a movable mirror 16, and the movable mirror 16 has a reflection point 16 a at the second focal point 12, and passes through the second focal point 12. The rotating mirror rotates around the center line C. For this reason, in order to change the incident direction of the laser beam R from the second focal point 12 to the ellipsoidal mirror 9, the movable mirror 16 may be rotated around the center line C, and the configuration is simple.

  FIG. 4 is a schematic configuration diagram in plan view of another embodiment of the photon beam scanning apparatus of the present invention. The scanning device shown in FIG. 4 is different from the scanning device shown in FIG. 1 with respect to the configuration of the laser light control unit 8, but the arrangement and the like based on the virtually set ellipse 10 are the same. For this reason, the description about the same structure is abbreviate | omitted here.

  The function of the laser light control unit 8 shown in FIG. 4 is the same as that of FIG. 1 and the function of changing the traveling direction of the laser light R from the second focal point 12 of the ellipse 10 toward a part of the ellipse 10. Have. Further, as in the case of FIG. 1, an ellipsoidal mirror 9 is installed on a part of the ellipse 10 to which the laser beam R from the second focal point 12 is directed.

  The laser light control unit 8 shown in FIG. 4 does not have the movable mirror 16 (see FIG. 1), but is a reflecting surface along a part of a virtually set parabola 40 having the second focal point 12 as a focal point. A parabolic mirror 41 having 42 is provided. Furthermore, in this embodiment, the laser light control unit 8 includes an optical device (periscope 29 in this embodiment) that translates the laser light R generated by the laser generator 2. In addition, the laser light control unit 8 includes a flat mirror 43 that reflects the laser light R incident from the periscope 29 and causes the laser light R to enter the parabolic mirror 41. The parabolic mirror 41 and the flat mirror 43 are installed in a fixed state.

  The parabolic mirror 41 reflects the laser light R generated by the laser generator 2 and made incident through the plane mirror 43 so as to pass through the second focal point 12. The virtually set parabola 40 is set on the same plane as the ellipse 10, and is set on a horizontal plane in the present embodiment. The parabolic mirror 41 is an off-axis parabolic mirror. The parabola 40 is not particularly limited with respect to the position and direction of the parabola 40 (the quasi-line 44 of the parabola 40). It is provided at a position that intersects with an extension of a straight line connecting the focal point 12.

  In the scanning device of FIG. 1, the laser beam R generated by the laser generator 2 is always incident on the second focal point 12, but in the scanning device of FIG. 4, the laser beam R is translated by the periscope 29, The point of incidence on the plane mirror 43 is changed. The reflection surface of the plane mirror 43 is a plane, and the incident angle and the emission angle of the laser light R are the same with respect to this reflection surface.

  5 and 6 are explanatory diagrams for explaining the function of the path control device 3. Similar to the above embodiment, the electron beam control unit 7 controls the path of the electron beam E so that the electron beam E is incident on the first focus 11 of the ellipse 10 and the incident angle on the first focus 11 is changed. In the vacuum container 20, an electron beam E having a path that always passes through the first focal point 11 of the ellipse 10 can be obtained.

As shown in FIG. 5, when the laser beam R generated by the laser generator 2 is incident on the plane mirror 43 by the periscope 29 through the first path G <b> 1, the reflected light is incident on the paraboloidal mirror 41. The laser beam R reflected by the parabolic mirror 41 passes through the second focal point 12 and enters the reflecting surface 19 of the ellipsoidal mirror 9. The reason why the laser beam R reflected by the parabolic mirror 41 passes through the second focal point 12 is that the light reflected by a part of the parabola gathers at the focal point of the parabola.
The path of the laser beam R incident on the ellipsoidal mirror 9 from the second focal point 12 is V11. The laser beam R reflected by the ellipsoidal mirror 9 is incident on the first focal point 11 at an incident angle θ11 and can collide with the electron beam E having the incident angle θ1 in a frontal collision.

As shown in FIG. 6, when the laser beam R is translated by the function of the periscope 29 and is incident on the plane mirror 43 through the second path G <b> 2, the reflected light is incident on the parabolic mirror 41. This incident point is a position different from the case where the laser beam R travels along the path G1. Then, the laser beam R reflected by the parabolic mirror 41 passes through the second focal point 12 and enters the reflecting surface 19 of the elliptical mirror 9. The path of the laser beam R incident on the ellipsoidal mirror 9 from the second focal point 12 is V12.
As described above, the laser light control unit 8 can change the traveling direction of the laser light R from the second focal point 12 of the ellipse 10 toward the ellipsoidal mirror 9 between V11 and V12.

  Therefore, if the generated laser light R is incident on the reflecting surface 42 of the parabolic mirror 41, the reflected laser light R can pass through the second focal point 12. Then, by changing the incident point of the laser light R to be incident on the reflecting surface 42 of the parabolic mirror 41 by the periscope 29, the traveling direction of the laser light R passing through the second focal point 12 toward the elliptical mirror 9 Can be changed. As a result, the incident angle of the laser beam R reflected by the ellipsoidal mirror 9 to the first focal point 11 can be changed according to (according to) the incident angle of the electron beam E.

The scanning method performed by the scanning device shown in FIG. 4 is the same as that of the scanning device shown in FIG. 1, but in the case of FIG. 1, the incident angle of the electron beam E to the first focal point 11 is changed from θ1 to θ2. In synchronization with this change, the moving mirror 16 is controlled to change the traveling direction (path) of the laser light R from the second focal point 12 toward the ellipsoidal mirror 9 from V1 to V2. However, in the case of FIG. 4, the incident point of the laser beam R on the paraboloidal mirror 41 is changed in synchronization with changing the incident angle of the electron beam E to the first focal point 11 from θ1 to θ2. Thus, the traveling direction (path) of the laser light R from the second focal point 12 toward the ellipsoidal mirror 9 is changed from V11 to V12. That is, the scanning device of FIG. 4 is an embodiment that moves the light source (the path of the laser light R until it passes through the second focal point 12).
The embodiment of FIG. 4 is effective when the movable mirror 16 as shown in FIG. 1 cannot be disposed at the second focal point 12 (for example, due to layout problems).

In each of the embodiments of FIGS. 1 and 4, even if the path of the laser light R from the second focal point 12 is changed, the first focal point 11 passes from the second focal point 12 via the reflection point on the ellipsoidal mirror 9. Since the path length of the laser beam R up to is constant (it does not change), even if the incident angle to the first focal point 11 is changed, the laser beam R that is a parallel beam is used as one point of the first focal point 11. It can be converged. That is, it is not necessary to adjust the focus on the light source side.
In each embodiment, the path control device 3 can adjust the incident angle of the electron beam E to the first focal point 11 with a total width of 10 ° (θ1 = 5 °, θ2 = 5 °), By following this adjustment, it is possible to adjust the incident angle of the laser beam R to the first focal point 11 with a total width of 10 ° (θ11 = 5 °, θ12 = 5 °). As a result, γ rays can be emitted in a wide range, and a wide range (wide) scanning can be performed on the scanning target 13.

In each of the above embodiments, since the ellipsoidal mirror 9 exists in the radiation direction of the photon beam, the ellipsoidal mirror 9 is made of a member that can transmit the photon beam (γ-ray) (a member having a high transmittance). For example, it is made of plastic, glass, or a metal with high transmittance (such as aluminum).
Further, a movable collimator 28 may be provided between the scanning object 13 and the first focal point 11 in order to partially cut the generated photon beam (its energy).
In addition, the beam diameter of the laser beam R generated by the laser generator 2 may be changed, whereby the spread of photon energy can be changed.

Moreover, the movable mirror 16 in FIG. 1 and the parabolic mirror 41 in FIG. 4 may be any material that reflects laser light.
In the embodiment of FIG. 4, the plane mirror 43 is provided in consideration of the arrangement of the laser generator 2 and the periscope 29, but may be omitted.
In the embodiment of FIG. 4, two electron beam controllers 7 having a vacuum vessel 20 and a plurality of deflection magnets are provided in series. The two electron beam control units 7 perform opposite deflection operations. That is, when the deflection angle is increased in the first (right side of FIG. 4) electron beam control unit 7, the deflection angle is decreased in the second (left side of FIG. 4) electron beam (laser generator). 2) The path length from the side to the end (electron beam dump 31) side is made constant.

Further, the scanning device of the present invention is not limited to the illustrated form, and may be other forms within the scope of the present invention.
In each of the above embodiments, the case where the electron beam and the laser beam collide with each other at the first focal point 11 has been described. However, the electron beam and the laser beam are incident on the first focal point 11 from the relatively inclined direction and collided with the first focal point 11. Also good. This makes it possible to change the energy of photons scattered by electrons.

Further, the scanning device can be applied as an image diagnostic apparatus in addition to the nondestructive inspection apparatus. Further, the high-energy photon beam generated by the scanning device may be X-rays other than γ-rays.
Further, γ-rays / X-rays having a certain energy width may be used instead of quasi-monochromatic γ-rays / X-rays (which have almost the same energy). In this case, the laser beam expander The spread of energy can be controlled by changing the diameter.
The scanning device can also be introduced into an energy recovery type system or an electron storage ring type system. In this case, as described above, according to the electron beam control unit 7 of the present embodiment, the incident and emission of the electron beam E in the vacuum vessel 20 can be set as fixed points. When the scanning device is introduced, the influence on the trajectory of the electron beam can be reduced.

1: electron beam generator, 2: laser generator, 3: path controller, 7: electron beam controller, 8: laser light controller, 9: ellipsoidal mirror, 10: ellipse, 11: first focus, 12 : Second focus, 13: scanning object, 16: movable mirror, 16b: reflecting surface, 19: reflecting surface, 40: parabola, 41: parabolic mirror, 42: reflecting surface, C: center line, E: electron Beam, R: Laser light

Claims (2)

An electron beam generator for generating an electron beam;
A laser generator for generating laser light;
A path control device for controlling the paths of the generated electron beam and laser light to collide the electron beam with the laser light, and
The route control device
An electron beam controller that controls the path of the electron beam to cause the electron beam to be incident on an elliptical first focal point that is virtually set, and to change the incident angle on the first focal point;
A laser light control unit that changes a traveling direction of the laser light from the second focal point of the ellipse toward a part of the ellipse;
An ellipsoidal mirror having a reflecting surface along the part of the ellipse and reflecting the laser light incident on the reflecting surface from the second focal point and incident on the first focal point from the opposite side of the electron beam; ,
Have,
The laser light control unit includes a parabolic mirror that has a reflecting surface along a part of a parabola with the second focal point as a focal point and reflects the laser light so as to pass through the second focal point. photon beam scanning apparatus characterized by there. A photon beam scanning method for controlling a path of an electron beam and a laser beam to collide the electron beam and the laser beam to generate a photon beam,
An electron beam control step of controlling the electron beam path to change the incident angle of the electron beam to the first focal point of the virtually set ellipse;
Laser light is incident on a parabolic mirror having a reflecting surface along a part of a parabola with the second focal point of the ellipse as a focal point, and the laser light reflected by the parabolic mirror is reflected on the second focal point. The laser beam travels from the second focal point to an elliptical mirror having a reflecting surface along a part of the ellipse by passing the laser beam and changing the incident point of the laser beam on the parabolic mirror. A photon beam scanning method comprising: a laser beam control step of changing a direction.

Images