WO2019037488A1

WO2019037488A1 - Ray irradiation apparatus and safety detection device

Info

Publication number: WO2019037488A1
Application number: PCT/CN2018/087676
Authority: WO
Inventors: 张颜民; 裘伟东; 黄毅斌; 丛鹏; 向新程; 童建民
Original assignee: 清华大学
Priority date: 2017-08-25
Filing date: 2018-05-21
Publication date: 2019-02-28
Also published as: CN107515427A

Abstract

A ray irradiation apparatus, comprising: a ray source (10), used for providing rays; a shielding shell (20), provided with a first cavity (21) for accommodating the ray source (10) and an opening (22) in communication with the first cavity so as to enable the rays to be radiated outwards by means of the opening (22); a grating ruler (30), used for acquiring position information of the ray source (10); and a control unit (40), used for controlling the ray source (10) to move to a first position or a second position according to the position information of the ray source (10), wherein the first position is the position where the ray is irradiated outwards by means of the opening (22), and the second position is a position where the ray may not be irradiated outwards by means of the opening (22). With the described apparatus, rays having high frequency may be emitted, impact produced by emission of the rays on the shielding shell (20) may be reduced, ray dose is reduced, and at the same time, difficulty of radiation protection is reduced. Also provided is a safety detection device comprising the ray irradiation apparatus.

Description

Radiation irradiation device and safety detecting device

Cross-reference to related applications

The present application claims priority to Chinese Patent Application No. 20171074369, filed on Aug. 25,,,,,,,,,,,,,,,,,

Technical field

The present application relates to the field of nuclear technology applications, and in particular, to a radiation irradiation device and a safety detection device.

Background technique

At present, radiological safety testing equipment has been widely used in stations, subways, airports, customs, ports, nuclear power plants, government agencies, postal inspection centers, courts, conference venues, etc., through the rays passing through the object to be tested, the detectors set up on the other side The signal is collected to obtain the intensity of the attenuation after the radiation penetrates different substances, to distinguish the density of the detected object, to obtain different grayscale images, and to perform security inspection on the object or the vehicle.

A dual projection radiation imaging detection technique for large trucks and containers is known in which an isotope is set as a radiation source. The radiation source is usually disposed in a thick shielding chamber, and an emission hole for emitting radiation is formed on the shielding chamber, and a shutter having a shielding function can block or expose the emission hole by reciprocating movement, so that the radiation can be at a certain frequency. The emission is performed from the emission hole, and the object to be detected is detected. However, due to the excessive weight of the shutter structure, the opening and closing speed of the shutter is slow, and the impact force is large, the opening time is long, the positioning is not accurate, and the radiation dose required for detection is large, and the shutter size is large.

Therefore, there is a need for a radiation irradiation apparatus having a shutter opening and closing speed, a small impact, and a safety detecting apparatus.

Application content

The present application provides a radiation irradiation device and a safety detection device, and aims to provide a radiation irradiation device and a safety detecting device which have a fast shutter opening and closing speed, a small impact, and a more precise positioning of a radiation source.

According to an aspect of the present application, there is provided a radiation irradiation apparatus comprising: a radiation source for providing radiation; a shielding case having a chamber for accommodating a radiation source and an opening communicating with the chamber such that radiation can pass through the opening Radiation; a scale for acquiring position information of the radiation source; and control means for controlling the movement of the radiation source to the first position or the second position according to the position information of the radiation source; wherein the first position is a radiation passage opening The location of the external radiation; the second location is where the radiation cannot radiate outward through the opening.

According to another aspect of the present application, a security detecting apparatus comprising the above-described radiation irradiating apparatus is provided.

The illuminating device provided by the embodiment of the present application has an opening on the shielding shell. The device of the embodiment of the present application does not realize the radiation of the ray by opening and closing the shutter, but the control device controls the ray source to be in the first position such that the ray passes through the opening. Radiating outward, or the second position, so that the radiation cannot be radiated outward through the opening, since the weight of the radiation source is much smaller than the weight of the shutter, so that the emission of the higher frequency radiation can be achieved, and the shielding shell due to the radiation emission can also be reduced. The impact force generated by the body, and the position information of the radiation source can be accurately obtained by the scale, and the control device controls the movement of the radiation source according to the position information of the radiation source, and can more precisely control the radiation source to be in the first position or the second position due to the radiation The source position is accurate, so the opening size can be reduced, so that the radiation dose is reduced while reducing the radiation protection difficulty.

DRAWINGS

Features, advantages, and technical effects of the exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic structural view showing a radiation irradiation apparatus according to an embodiment of the present application.

DESCRIPTION OF REFERENCE NUMERALS: 10, ray source; 20, shielding case; 21, first chamber; 22, opening; 23, second chamber; 24, mounting hole; 30, grid; 40, control device; , mounting rod; 60, drive mechanism; 61, stator; 62, mover; 70, support; 71, base; 72, side wall; 73, guide rail; 74, slider; 75, pointer; 80, reset device; 81, bracket; 82, connecting ring; 91, the first limit sensor; 92, the second limit sensor.

Detailed ways

Features and exemplary embodiments of various aspects of the present application are described in detail below. In the following detailed description, numerous specific details are illustrated and However, it will be apparent to those skilled in the art that the present disclosure may be practiced without some of the details. The following description of the embodiments is merely provided to provide a better understanding of the present application. The application is not limited to any specific configuration presented below, but any modifications, substitutions and improvements made to the structure and components of the application are covered without departing from the spirit of the invention. In the drawings and the following description, well-known structures and techniques are not shown to avoid unnecessarily obscuring the technical solutions of the present application.

1 is a schematic structural diagram of a radiation irradiation apparatus according to an embodiment of the present application. The radiation irradiation apparatus can be installed in a detection channel of a plurality of types of safety detection devices (not shown) for using an object to be detected as needed (exemplary The ground, such as a vehicle or a container, emits a detection ray, and cooperates with a detector disposed in the detection channel and other units to detect the detected object.

Referring to FIG. 1, a radiation irradiation device includes a radiation source 10 for providing radiation; a shielding housing 20 having a first chamber 21 for accommodating the radiation source 10 and an opening 22 communicating with the first chamber 21 such that the radiation The radiation source 10 can be moved to the first position or the second position according to the position information of the radiation source 10; The first position is the position at which the radiation radiates outward through the opening 22; the second position is the position at which the radiation cannot be radiated outward through the opening 22.

The shielding housing 20 of the radiation irradiation device provided by the embodiment of the present application has an opening 22, and the device of the embodiment of the present application does not realize radiation of radiation by opening and closing of the shutter, but the control device 40 controls the radiation source 10 to be in the first position. The radiation is radiated outward through the opening 22, or the second position is such that the radiation cannot be radiated outward through the opening, since the weight of the radiation source 10 is much smaller than the weight of the shutter, thereby enabling emission of higher frequency rays while also reducing Since the radiation strikes the impact force generated on the shield case 20, and the position information of the radiation source 10 can be accurately acquired by the scale 30, the control device 40 controls the movement of the radiation source 10 according to the position information of the radiation source 10, and can control the radiation more accurately. The source 10 is in the first position or the second position, and since the position of the radiation source 10 is accurate, the size of the opening 22 can be reduced, so that the radiation dose can be reduced while reducing the radiation protection difficulty.

In some alternative embodiments, the shielded housing 20 is constructed of a material having shielding properties that provide better shielding and higher strength. For example, it can be made of high-density metals or alloys such as lead, tungsten, lead alloy or tungsten alloy, uranium 238. The main body of the shielding case 20 has an elliptical spherical structure, can be mounted on the radiation irradiation device mounting seat of the detecting channel, has a first chamber 21 for accommodating the radiation source 10 therein, and the opening 22 provided on the shielding housing 20 is The actual illumination needs to be selected as a circular hole or a slit-like opening. For example, as shown in FIG. 1, the opening 22 may be directly opened on the main body of the shielding case 20. Of course, the position of the opening 22 may be determined according to the position of the radiation source 10 in the chamber as long as the radiation source 10 can be aligned. The first position of the opening 22 or the second position of the opening 22 may be.

Since the opening 22 of the embodiment of the present application is formed on the elliptical spherical structure, when the opening 22 is in the shape of a slit, the angle of the opening can be maximized on the shielding shell 20, so that the radiation irradiation device ensures a good shielding effect. At the same time, it can have a larger opening angle, that is, a wider radiation area. Therefore, it can be arranged as close as possible to the detection object, reducing the space occupied by the entire inspection device. In some embodiments, when the opening 22 is slit-shaped, and since the shield case 20 itself has a sufficient thickness, the opening 22 can also be used as a collimator of the radiation irradiating device for extracting the detected rays and shaping the detected rays. And the size constraint, so that the ray is collimated to a large fan-shaped area with the ray source 10 as the apex, which can involve the entire detection object, so that not only the radiation provided by the ray source 10 is not repeated, not leaking and no The dead angle can make the detection ray strictly aligned with the corresponding detector (not shown), improve the detection efficiency and the quality of the detected image, so that the object to be measured can be detected more accurately.

Of course, the structure of the shielding case 20 is not limited thereto. In order to ensure uniform thickness distribution and easy installation, the shielding case 20 in this embodiment adopts an elliptical spherical structure, and in other embodiments, it may also be a square body. A cylinder or other housing structure as long as its thickness can meet the shielding needs.

The embodiment of the present application does not limit the type of the radiation source 10. For example, the radiation source 10 may be a gamma ray source. The gamma ray source includes an isotope source, and specifically, may include: ⁶⁰ Co, ¹³⁷ Cs, ¹⁹² Ir, ⁷⁵ Se, preferably ⁶⁰ Co, which has high energy and can match the larger opening angle provided by the opening 22 to form a stronger The fan-shaped scanning surface performs more accurate scanning detection on the object to be measured.

In some alternative embodiments, the source 10 is mounted in the chamber by a mounting portion such that the first chamber 21 inside the shield housing 20 is correspondingly disposed in accordance with the shape of the mounting portion of the source 10 of radiation. The first position and the second position are formed according to the mating state of the radiation source 10 and the opening 22 with each other. Control device 40 can then move source 10 relative to opening 22 between a first position and a second position.

It can be understood that the mounting portion can be a mounting rod 50, the mounting rod 50 can be moved within the shielding housing 20, the radiation source 10 is fixedly disposed on the mounting rod 50, and the scale 30 is used to obtain position information of the mounting rod 50, and the control device 40 is used to control the movement of the mounting rod 50 according to the positional information of the mounting rod 50 such that the radiation source 10 is in the first position or the second position.

In other alternative embodiments, the source 10 is fixedly disposed within the mounting bar 50. The mounting bar 50 includes a thin wall portion on the mounting bar 50 at a position opposite the source 10, ie, the mounting bar 50. The position at which the rays of the ray source 10 are emitted, the wall thickness of the thin portion is less than or equal to the thickness preset value. In these optional embodiments, the thickness preset value may be set according to actual requirements, as long as the wall thickness of the mounting rod 50 is less than or equal to the thickness preset value, the radiation of the radiation source 10 can penetrate the mounting rod 50 to radiate. Just go out. The position of the mounting rod 50 other than the thin portion is made of a shielding material to prevent radiation from being emitted from other locations.

It can be understood that, in other optional embodiments, the first chamber 21 further includes a mounting hole 24, the mounting rod 50 is located within the mounting hole 24, and is movable within the mounting hole 24; the shielding housing 20 further includes The second chamber 23 is disposed at the second end of the mounting rod 50. In these alternative embodiments, by providing the second chamber 23, the mounting bar 50 can be enclosed in the shield housing 20 to prevent removal of the mounting bar from the mounting hole 24 at the second end of the mounting bar 50. Further, the second chamber 23 is provided with a lock, and the second chamber 23 cannot be opened without unlocking to take out the mounting rod 50. In these alternative embodiments, the difficulty of removing the mounting bar 50 can be increased by the locks in the second chamber 23 and the second chamber 23, preventing the user from accidentally removing the mounting bar 50, causing a radiation leakage accident. Specifically, in order to ensure the smoothness and safety of the radiation source 10 in the linear reciprocating motion, the mounting hole 24 is disposed perpendicular to the opening 22, and the mounting rod 50 is reciprocally disposed in the mounting hole 24.

In some alternative embodiments, the diameter of the mounting aperture 24 and the diameter of the mounting bar 50 are less than or equal to a predetermined difference. In these alternative embodiments, the preset difference can be set according to actual needs, so that the dose of radiation radiated from the end of the mounting hole 24 away from the second chamber 23 satisfies the shielding requirement. In these alternative embodiments, since the radiation is radiated in a certain direction, when the diameter of the mounting hole 24 is small, that is, the gap between the mounting hole 24 and the mounting rod 50 is small, the radiation dose is limited. Can meet the shielding requirements.

In still other alternative embodiments, the second position is spaced from the end of the mounting aperture 24 away from the end of the second chamber 23 by a distance greater than or equal to the first predetermined distance. The first preset distance can be set according to actual requirements, so that the dose of radiation radiated from the end of the mounting hole 24 away from the second chamber 23 satisfies the shielding requirement.

In still other alternative embodiments, the distance of the opening 22 from the end of the mounting aperture 24 away from the second chamber 23 is greater than or equal to a second predetermined distance. The second preset distance can be set according to actual requirements, so that the dose of radiation radiated from the end of the mounting hole 24 away from the second chamber 23 satisfies the shielding requirement.

In still other alternative embodiments, further, the radiation illuminating device further includes a driving mechanism 60 including a stator 61 and a mover 62 reciprocable along the stator 61, the first of the mover 62 and the mounting rod 50 The terminal is fixedly connected, the scale 30 is used to acquire the position information of the mover 62, and the control device 40 is configured to control the movement of the mover 62 according to the position information of the mover 62 so that the radiation source 10 is located at the first position or the second position. Wherein, the second end of the mounting rod 50 is reciprocable within the mounting hole 24 and the second chamber 23. Specifically, the driving mechanism 60 adopts a linear motor, and the mover 62 of the linear motor is connected to the mounting rod 50, or is indirectly coupled with the mounting rod 50 through a connecting rod. Of course, the connection between the mover 62 and the mounting rod 50 is used in the present application. The method is not limited, as long as the detachable fixed connection between the two can be realized, the control device 40 can control the movement of the mover 62 to drive the mounting rod 50 to linearly reciprocate in the axial direction of the mounting hole 24, that is, The radiation source 10 can be moved and the radiation source 10 can be switched between the first position and the second position. With the height characteristics of the linear motor, the control device 40 can quickly control the movement of the radiation source 10 to the first position or the second position. According to the position information acquired by the scale 30, the accuracy of the control can be ensured while ensuring that the radiation source 10 is quickly controlled to move to the first position or the second position.

In some alternative embodiments, the cross-section of the mounting bar 50 can also be square, rectangular or other shape that can be linearly reciprocated as long as it cooperates with the mounting aperture 24.

In some optional embodiments, further, the radiation illuminating device further includes a support 70. The support 70 includes a base 71 and two side walls 72. The two side walls 72 are located at two sides of the base 71 along the axial direction of the mounting rod 50. On the side, the stator 61 is fixedly disposed between the two side walls 72.

The base 71 is provided with a guide rail 73, and the mover 62 is reciprocable along the guide rail 73 to reciprocate the mover 62 along the stator 61. In these alternative embodiments, the guide rails 73 carry the mover 62 for reciprocation to avoid damage to the components caused by the reciprocating movement of the mover 62 by the stator 61 due to insufficient strength of the stator 61.

There are various embodiments of the connection between the mover 62 and the guide rail 73. As an alternative embodiment, the guide rail 73 further includes a slider 74, a mover 62 and a slider that can reciprocate along the guide rail 73. 74 connections.

In other optional embodiments, the scale 30 is disposed at the bottom of the guide rail 73, and the measuring direction of the scale 30 coincides with the reciprocating direction of the mover 62. The slider 74 is provided with a pointer 75, and the tip of the pointer 75 is pointed. The scale 30 is adjacent to the side of the slider 74 for indicating the scale displayed on the scale 30. In these alternative embodiments, the tip end of the pointer 75 is directed toward the scale 30 so that the positional information of the slider 74, i.e., the positional information of the mover 62 attached to the slider 74, can be read from the scale 30. Of course, the scale 30 can also be disposed at other positions as long as the scale 30 can acquire the position information of the mover 62.

In still other alternative embodiments, the radiation illuminating device further includes a reset device 80 fixedly coupled to the mover 62. The reset device 80 is repositioned to move the mover 62 such that the source 10 is in the first or second position. . Optionally, the reset device 80 can be an uninterruptible power supply (English name: Uninterruptible Power System/Uninterruptible Power Supply, UPS), a super capacitor or a compression spring.

Specifically, the resetting device 80 is a compression spring. The first end of the compression spring is coupled to the mover 62. The compression spring is elastically deformed to move the mover 62 to position the radiation source 10 in the first position or the second position. In some alternative embodiments, when the mover 62 is moved from a first position corresponding to the source 10 to a second position corresponding to the source 10, the mover 62 does the motion of compressing the compression spring. Specifically, when the mover 62 is at a position corresponding to the second position of the radiation source 10, the compression spring is in a naturally elongated state, and when the mover 62 is at a position corresponding to the first position of the radiation source 10, the compression spring is at Compressed state. In these alternative embodiments, when the radiation source 10 emits radiation radiation and a sudden power failure occurs, the mover 62 is moved to a position corresponding to the second position of the radiation source 10 by the elastic force of the compression spring, thereby The radiation cannot be radiated from the opening 22.

In some optional embodiments, the radiation illuminating device further includes a bracket 81 fixedly disposed at one end on the shield case 20, and the compression spring is sleeved on the bracket 81, and the first end of the compression spring passes through the connecting ring 82 and the mover 62. The fixed connection, the connecting ring 82 is sleeved on the bracket 81, and the second end of the compression spring is fixedly disposed on the shielding shell 20. Of course, one end of the bracket 81 can also be fixed at other positions of the radiation irradiating apparatus of this embodiment. Similarly, the second end of the compression spring can also be attached to other locations of the radiation irradiation apparatus of the present embodiment. In these alternative embodiments, when the mover 62 is moved by the elastic force of the compression spring, the mover 62 can be moved along the bracket 81 due to the restriction of the bracket 81 and the connecting ring 82. Further optionally, the bracket 81 is disposed in parallel with the stator 61, and the mover 62 reciprocates along the bracket 81 to reciprocate the mover 62 along the stator 61.

In still other alternative embodiments, the travel of the mover 62 is greater than or equal to the distance between the first position and the second position. In these alternative embodiments, the travel of the mover 62 ensures that the mover 62 causes the source 10 to move to the first or second position.

In other optional embodiments, the radiation irradiation device further includes a first limit sensor 91 and/or a second limit sensor 92, and the first limit sensor 91 is configured to determine whether the radiation source 10 is in the first position, The second position sensor 92 is configured to determine whether the radiation source 10 is in the second position. The control device 40 is further configured to determine whether to control the radiation source 10 to stop moving according to the determination result of the first limit sensor 91 and/or the second limit sensor 92. . In these alternative embodiments, when the control device 40 is used to control the radiation of the radiation to the outside, and the first limit sensor 91 determines that the radiation source 10 is in the first position, the control device 40 controls the radiation source 10 to stop moving; The device 40 is for controlling the radiation to be unable to radiate outward, and the second limit sensor 92 determines that the radiation source 10 is in the second position, and the control device 40 controls the radiation source 10 to stop moving. The control device 40 is further configured to determine, according to the position information acquired by the scale 30, a corresponding position of the first position and the second position of the radiation source 10 on the scale 30, and the first limit sensor 91 is disposed on the scale 30. At a position of the first position of the ray source 10, the second limit sensor 92 is disposed on the scale 30 at a position corresponding to the second position of the ray source 10.

A second embodiment of the present application provides a security detecting apparatus, including the radiation irradiating apparatus of any of the above embodiments. According to the safety detecting device (for example, detecting the vehicle) provided by the embodiment of the present application, the above-described radiation irradiating device is installed, and the radiation irradiating device can be installed on the bottom surface, the top surface or the side surface of the detecting passage of the safety detecting device. Preferably, the radiation irradiation device is mounted on the bottom surface of the detection channel. Since the radiation irradiation device in the embodiment of the present application has a large radiation opening angle, during the detection process, it is mounted on the bottom surface of the detection channel between the vehicle and the detection vehicle. Maintaining a close distance while having a wide radiation area facilitates a clearer detection image.

In an embodiment of the root play application, the safety detecting device further includes a sensor for detecting a vehicle to be detected in the detecting channel, and the sensor detects that the moving target enters the detecting channel of the safety detecting device and the cab passes the radiation detecting device, and then the information Transmitted to the control device 40, the control device 40 controls the radiation source 10 to move to the opening 22 of the shielding housing 20, and cooperates with the detector provided in the detection channel to perform scanning detection on the vehicle to be detected. Of course, the radiation source can be made as needed. 10 continuously scans the detection vehicle at the opening 22 or periodically scans the detection source by the drive mechanism 60. When the sensor detects that the detection vehicle has completed the detection, the information is transmitted to the control device 40 again, and the control device 40 controls the radiation source 10 to move to the second position, and the vehicle can exit the detection channel. The safety detecting device in this embodiment is equipped with the above-mentioned radiation irradiation device, and can control the quick opening or closing of the shutter of the radiation irradiation device according to the entry condition of the vehicle to be detected, thereby facilitating the convenient and reasonable control of the radiation irradiation device. To improve the detection efficiency, ensure the accuracy of the test results, and avoid the impact of the radiation irradiation device itself.

Claims

A radiation irradiation device comprising:

a source of radiation for providing radiation;

a shield housing having a first chamber for receiving the source of radiation and an opening in communication with the first chamber such that the radiation can radiate outward through the opening;

a scale for acquiring position information of the radiation source;

Control means for controlling the movement of the radiation source to the first position or the second position according to the position information of the radiation source;

Wherein the first position is a position where the ray radiates outward through the opening; and the second position is a position at which the ray cannot radiate outward through the opening.
The radiation irradiation apparatus according to claim 1, further comprising a mounting rod movable in said shield case, said radiation source being fixedly disposed on said mounting bar, said scale being used for acquiring The position information of the mounting rod, the control device is configured to control the movement of the mounting rod according to position information of the mounting rod such that the radiation source is located at the first position or the second position.
The radiation irradiation apparatus according to claim 2, wherein said first chamber further comprises a mounting hole, said mounting rod being located within said mounting hole and movable within said mounting hole; said shield housing A second chamber disposed at the second end of the mounting rod is also included.
The radiation irradiation apparatus according to claim 3, wherein a diameter difference between said mounting hole and said mounting rod is less than or equal to a preset difference.
A radiation irradiation apparatus according to claim 3, further comprising a driving mechanism including a stator and a mover reciprocable along said stator, said mover and said mounting rod One end is fixedly connected, the scale is used to acquire position information of the mover, and the control device is configured to control the movement of the mover according to the position information of the mover, so that the radiation source is located at the The first location or the second location.
A radiation irradiation apparatus according to claim 5, further comprising a holder, said holder comprising a base and two side walls, said two side walls being located at said base along said mounting rod axial direction On both sides, the stator is fixedly disposed between the two side walls.
The radiation irradiation apparatus according to claim 6, wherein said base is provided with a guide rail, and said mover is reciprocable along said guide rail to reciprocate said mover along said stator.
The radiation irradiation apparatus according to claim 7, wherein said guide rail further comprises a slider reciprocable along said guide rail, said mover being coupled to said slider.
The device according to claim 8, wherein the scale is disposed at a bottom of the guide rail, and a measuring direction of the scale is coincident with a reciprocating direction of the mover, and a pointer is disposed on the slider. The top end of the pointer points to a side of the scale adjacent to the slider for indicating a scale displayed on the scale.
A radiation irradiation apparatus according to claim 5, further comprising reset means fixedly coupled to said mover, said reset means resetting deformation to move said mover such that said source of radiation is located at said first Location or the second location.
The device according to claim 10, wherein said resetting means is a compression spring, said first end of said compression spring being coupled to said mover, said compression spring being elastically deformed to move said mover The source of radiation is located at the first location or the second location.
The device according to claim 11, further comprising a bracket fixedly disposed at one end on the shield case, the compression spring being sleeved on the bracket, the first end of the compression spring passing The connecting ring and the mover are fixedly connected, the connecting ring is sleeved on the bracket, and the second end of the compression spring is fixedly disposed on the shielding shell.
The radiation irradiation apparatus according to claim 5, wherein a movement stroke of the mover is greater than or equal to a distance between the first position and the second position.
The radiation irradiation apparatus according to claim 1, further comprising a first limit sensor and/or a second limit sensor, wherein said first limit sensor is for determining whether said radiation source is located at said first position The second limit sensor is configured to determine whether the radiation source is located in the second position;

The control device is further configured to determine whether to control the radiation source to stop moving according to the determination result of the first limit sensor and/or the second limit sensor.
A safety detecting apparatus comprising: the radiation irradiating apparatus according to any one of claims 1-14.