JPH0581776U - Screen monitor - Google Patents

Abstract

(57) [Summary] [Object] To provide a low-cost screen monitor that is compact in shape, easy to install, and simple in structure. [Structure] A fluorescent plate 37 is attached to a bearing portion 36 provided on the peripheral edge of the opening 32 of a cylindrical port portion 33 projecting to the outside of the duct 31 from an opening 32 opened in the middle of the duct 31 in which electrons travel. Is swingably supported. Then, the shape memory alloy spring 38 selectively disposes the fluorescent plate 37 at the monitoring position (I) and the opening position (II).

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a screen monitor for monitoring the position, shape and intensity of an electron beam in a synchrotron radiation device, an accelerator, a transport, a beam line or the like.

[0002]

[Prior Art]

 Generally, in this type of screen monitor, a fluorescent plate is arranged in the course of the electron beam traveling path in a synchrotron radiation device, accelerator, transport or beam line, etc., and the fluorescent plate is made to collide with the electron beam to emit light. This light is made incident on a television camera or the like to monitor the position, shape, and intensity of the electron beam.

For example, as shown in FIG. 3, electrons are accelerated in a duct 1 arranged in a loop and maintained in an ultrahigh vacuum, and the direction of travel of the accelerated electrons is determined by using a superconducting deflection electromagnet 2. In a synchrotron radiation device that deflects and emits so-called synchrotron radiation from accelerated electrons during this deflection, screen monitors 3, 3, ... Are arranged at a plurality of locations in the duct 1, and these screen monitors 3, 3. The position, shape, intensity, etc. of the electron beam in the duct 1 are monitored by 3, ...

An example of a conventional screen monitor 3 used in the synchrotron radiation device is shown in FIGS. 4 and 5. The screen monitor 3 is provided with a linear introduction machine 5 using a stepping motor 4, and a fluorescent plate 6 made of alumina ceramics containing chromium oxide is tilted by 45 degrees with respect to an electron beam traveling in the duct 1. Then, it is moved back and forth in the duct 1. When the fluorescent plate 6 is inserted into the duct 1, the electron beam collides with the fluorescent plate 6 and the fluorescent plate 6 emits light. This emitted light enters an unillustrated television camera through an observation window 7 of a port provided in the duct 1, and a video signal output from this television camera is input to a television monitor to determine the position of the electron beam, Monitor the shape and strength.

As shown in FIG. 5, the straight line introducing machine 5 of the screen monitor 3 includes a motor support plate 8 for supporting the stepping motor 4 and a plate 9 arranged so as to face the motor support plate 8. The worm 11 is rotatably supported between the worm 11, a worm gear 12 is screwed onto the worm 11, and the other end of a shaft 14 formed by fixing the holder 13 of the fluorescent plate 6 to one end is fixed to the worm gear 12. The rotation of 11 causes the worm gear 12 to move forward and backward, so that the fluorescent plate 6 held by the holder 13 moves forward and backward into the duct 1. The plate 9 has a connecting flange 16 for connecting the straight line introducing machine 5 to the fixing flange 15 (see FIG. 4) on the duct 1 side, and the connecting flange 16 and the plate 9 are integrated by the connecting portion 17. And the holder 13 of the fluorescent plate 6 is linearly displaced inside. The connecting portion 17 communicates with the duct 1 and maintains a vacuum inside the duct 1, so that the seal mechanism 18 seals between the plate 9 and the shaft 14 of the holder 13.

A belt 23 is stretched between a pulley 21 fixed to the protruding end of the worm 11 from the motor support plate 8 and a pulley 22 fixed to the output shaft 4 a of the stepping motor 4, and the stepping motor 4 As a result, the worm 11 is driven, and the worm gear 12 is linearly displaced. The stepping motor 4 is rotationally driven by a motor control 24. When the worm gear 11 reaches the most advanced position and the most retracted position, the protrusion 12a provided on the worm gear 12 kicks the actuators 25a, 26a of the limit switches 25, 26, and the limit switches 25, 26 drive the motors. A signal is input to the control 24 to stop the stepping motor 4.

As a drive source for the fluorescent plate 6 of the straight line introduction machine 5, there is a drive source that uses compressed air in addition to the drive source that uses the stepping motor 4 as described above.

[0008]

[Problems to be solved by the device]

 By the way, in the small synchrotron radiation device developed for industrial use as shown in FIG. 3, the screen monitor 3 is required to be as compact as possible due to its use. However, in the above-mentioned conventional screen monitor 3, as can be seen from the above, in order to collide the electron beam with the fluorescent plate 6, the stepping motor 4 and the air pressure of the compressed air are used to cause the fluorescent plate 6 to move against the electron beam. In addition to providing a port 15 for mounting the straight line introducing device 5 for moving up and down or back and forth, the port 15 can only pass the fluorescent plate 37 through the opening so as not to cause a step difference in the duct 1 to suppress beam instability. The slit plate 27 is welded, and the straight line introduction machine 5 is attached to the port 15. For this reason, there has been a problem that the outer dimensions of the screen monitor 3 are several times larger than the duct 1.

An object of the present invention is to provide a low-cost screen monitor that is compact in shape, easy to install, and simple in structure.

[0010]

[Means for Solving the Problems]

 Therefore, the present invention is a screen monitor that is placed in the middle of a duct whose inside is maintained in an ultra-high vacuum state and that monitors the position, shape, and intensity of the electron beam accelerated in this duct. And a cylindrical port portion that protrudes to the outside of the duct from an opening opened in the middle of the duct, and the opening on the protruding end side is closed by a light transmitting plate made of a light transmitting material, and the duct. An electron beam that accelerates in the duct collides with a bearing section that is provided around the opening of the opening to emit light, and the emitted light is extracted from the light transmission plate of the port section to the outside of the duct. A fluorescent plate that is swingably supported between the monitoring position of the electron beam and the opening position, and one end is attached to the port and the other end is attached to the fluorescent plate to monitor the fluorescent plate. Position and the I unit if on the open position consist selectively positioned to shape memory alloys, it is characterized in that a current supply means for raising the temperature by energizing the spring means.

[0011]

[Action]

 When the temperature is raised by energization by the energizing means and the shape memory temperature is reached, the spring means returns to the memorized shape. As a result, the fluorescent plate is rotated around the bearing portion and stopped and held at the opening position. When the energization is stopped and the temperature of the spring means decreases, the spring means exits the shape memory state. As a result, the fluorescent plate is placed at the electron beam monitoring position.

[0012]

[Effect of the device]

 According to the present invention, the fluorescent plate is selectively placed at the electron beam monitoring position and the aperture position by the beam means made of a small shape and compact shape memory alloy, so that the mechanism for driving the fluorescent plate is simple. In addition, the amount of projection from the duct is reduced, and a compact and low-cost screen monitor can be obtained.

[0013]

【Example】

 Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 and 2 show an embodiment in which the screen monitor according to the present invention is applied to monitor an electron beam accelerated in a duct in a synchrotron radiation device.

In FIG. 1 and FIG. 2, the inside of the duct 31 is maintained in an ultra-high vacuum state, and electrons are accelerated inside the duct 31 to travel. An opening 32 is formed in the duct 31 in the middle thereof, and the port portion 33 is welded to the outside of the duct 31 through the opening 32. The opening 34 on the protruding end side of the port 33 is closed by a light transmitting plate 35 made of a light transmitting material.

A bearing portion 36 is provided on the peripheral edge of the opening 32 formed in the duct 31, and a fluorescent plate 37 is swingably supported by the bearing portion 36 at one end thereof. The fluorescent plate 37 is tilted from the bearing portion 36 into the duct 31 by the springs 38 made of a shape memory alloy, and the electron beam monitoring position (I) at which the electron beam accelerating in the duct 31 collides with the above-mentioned (I). It is selectively arranged at an opening position (II) that closes the opening 32 of the duct 31. The fluorescent plate 37 has a position of 45 ° with respect to the electron beam accelerated in the duct 31 by the stopper 39 attached to the duct 31 in parallel with the bearing portion 36 at the monitoring position (I) of the electron beam. It is regulated to make an angle. The light of the fluorescent plate 37 emitted by the collision of the electron beam passes through the light transmitting plate 35 of the port portion 33 and is incident on the television camera 41 arranged opposite thereto.

The shape memory alloy springs 38, 38 are conductively fixed to the projecting end of the current introducing terminal 42 fixed to the port portion 33 into the port portion 33, and the other end is It is fixed to the tip of the fluorescent plate 37. The current introduction terminal 42 supplies a current to the shape memory alloy.

In such a configuration, the shape memory alloy springs 38, 38 are always energized from the above energizing terminals. Due to the Joule heat due to this energization, the temperature of the springs 38, 38 exceeds the memorized shape temperature and holds the memorized shape. In the state where the storage shape is maintained, the springs 38, 38 exert a spring force on the tip portion of the fluorescent plate 37. As a result, the fluorescent plate 37 is held at the opening position of the duct 31. In this state, the fluorescent plate 37 is retracted from the electron beam path in the duct 31.

On the other hand, when the energization is stopped and the temperatures of the springs 38, 38 drop, the springs 38, 38 come out of the shape memory state. As a result, the fluorescent plate 37 rotates around the bearing portion 36 due to its weight and descends into the duct 31 until it comes into contact with the stopper 39. In this state, the electron beam in the duct 31 collides with the fluorescent plate 37, and light 43 is emitted from the fluorescent plate 37. The light 43 passes from the fluorescent plate 37 through the port portion 33, the light transmitting plate 35 and the television camera 41 to be monitored.

As described above, the fluorescent plate 37 can be selectively arranged at the monitoring position (I) and the opening position (II) by using the shape memory alloy spring 38 having a small shape and compact size. As a result, the screen monitor has a simplified mechanism for driving the fluorescent screen 37. Further, the screen monitor is compact, the amount of projection from the duct 31 is small, and the cost is low.

The present invention is not limited to a screen monitor that monitors the position, shape, intensity, etc. of an electron beam in a synchrotron radiation device, and can be applied to a screen monitor such as an accelerator, transport, or beam line. You can

[Brief description of drawings]

FIG. 1 is a side view showing a configuration of an embodiment of a screen monitor according to the present invention.

2 is a cross-sectional view of the screen monitor of FIG.

FIG. 3 is an explanatory diagram of a synchrotron radiation device.

FIG. 4 is an explanatory diagram showing a structure of a conventional screen monitor.

5 is an explanatory view of a straight line introduction machine for moving a fluorescent screen of the screen monitor of FIG. 4 forward and backward.

[Explanation of symbols]

 31 Duct 32 Opening 33 Port Part 34 Opening 35 Light Transmission Plate 36 Bearing Part 37 Fluorescent Plate 38 Spring of Shape Memory Alloy 39 Stopper 41 Television Camera 42 Current Introducing Terminal 43 Light

Claims (1)

[Scope of utility model registration request] 1. A screen monitor which is disposed in the middle of a duct whose inside is maintained in an ultra-high vacuum state and which monitors the position, shape, intensity, etc. of an electron beam accelerated in the duct. A cylindrical port portion that is projected from the opening opened in the middle of the duct to the outside of the duct, and the opening on the protruding end side is closed by a light transmitting plate made of a light transmitting material. The electron beam accelerated in the duct collides with the bearing provided on the periphery of the opening to emit light, and the emitted light is extracted from the light transmitting plate of the port to the outside of the duct. A fluorescent plate that is swingably supported between a monitoring position and the opening position, one end of which is attached to the inside of the port and the other end of which is attached to the fluorescent plate. 1. A screen monitor, comprising: a spring means made of a shape memory alloy selectively arranged in a storage unit; and an energization means for energizing the spring means to raise the temperature.