JPH11354288A - Soft x-ray generator for irradiation use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a soft X-ray generator for irradiation use excellent in safety, capable of realizing a stable X-ray dosage rate in a large X-ray dosage and capable of continuously irradiating X-rays for many hours. SOLUTION: A soft X-ray generator for irradiation has device main bodies 1, 2, 5, 7 having X-ray tube bulbs arranged in an X-ray irradiating material chamber, high frequency power source devices 6, 8 for supplying a stabilized high voltage driving power source to the X-ray tube bulbs and cooling systems 13, 15 for cooling the X-ray tube bulbs. The device main bodies offer safety. The power source devices realize a stable X-ray dosage rate in a large X-ray dosage. Continuous irradiation can be attained by using the above cooling systems for many hours.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soft X-ray generator for irradiation capable of continuously using a large X-ray at a stable X-ray rate for a long time, and more particularly to irradiating animals and plants with X-rays. The present invention relates to a soft X-ray generator for irradiation which can be used for the development of new species and the improvement of quality in fields such as medicine, agriculture, forestry, and fisheries by utilizing various reactions caused thereby.

[0002]

2. Description of the Related Art In an X-ray irradiator, most of high-speed energy for generating X-rays is converted into heat at the focal point of an X-ray tube. This heat is not particularly a problem in X-ray photography and non-destructive inspection X-ray fluoroscopy, which are used continuously for several seconds to several minutes at a low tube current of about 0.5 to 2 mA. However, in an X-ray irradiation apparatus that performs continuous irradiation for several hours with a large X-ray dose (large tube current), how to treat this heat is one of the important issues.

An X-ray irradiator that continuously irradiates a large amount of X-ray for a long time has a problem of shortening the life of the X-ray tube due to overload of heat generation. This is because the temperature of the X-ray tube rises in proportion to the use time, which may cause breakage in an overloaded state. In order to improve this point, generally, the insulating oil in the container containing the X-ray tube is indirectly water-cooled or air-cooled at room temperature, but since the heat exchange rate is poor, the capacity of the oil tank used is As a result, the entire apparatus becomes larger.
When another cooling device (cooling medium) is used in combination to enhance the heat radiation effect, the entire device is further increased in size, and the installation location and price are restricted.

[0004] Another important issue of the X-ray irradiator is to continuously and accurately irradiate a required X-ray dose. For this purpose, it is important that the drive power supplied to the X-ray tube is constant and stable. When the X-ray irradiator is driven by the same power supply as other equipment, the power supply load fluctuates due to the usage of other equipment, especially on / off control. The rate fluctuates greatly, which adversely affects the X-ray irradiation operation assuming a constant X-ray dose rate.

Conventionally, DC rectification methods for generating X-rays include a self-rectification method using an X-ray tube (half-wave rectification method) and a full-wave rectification method using a rectifying element. Require large and heavy high-voltage transformers. A commercial power supply voltage (AC100) input to an X-ray irradiator having a tube voltage of 30 to 100 kVp and a tube current of about 0 to 10 mA.
When V) changes, the change directly affects the tube voltage and the tube current, so that the X-ray dose also changes significantly.

In order to improve this point, it is necessary to use an automatic power supply adjusting device dedicated to the X-ray irradiation device. This type of power supply adjusting device with high accuracy such as response speed and waveform distortion is usually expensive and large and heavy, and is not suitable for movement. To improve this,
Although a power supply device using a high-frequency circuit method has been developed, it is limited to a low tube current region due to problems in design and component development and applications of the X-ray generator.

[0007]

In the X-ray generator for irradiation, in order to achieve an X-ray dose by a large current and a stable X-ray rate, it is desired to develop a power supply unit for irradiation by a unique high-frequency circuit. . This is one problem to be solved by the present invention. On the other hand, the problem of the conventional indirect cooling system in order to efficiently cool the X-ray tube so that it can be used continuously for a long time is as described above. This is another problem to be solved by the present invention. Furthermore, the irradiation X-ray generator must not adversely affect the operator and the surrounding people. This is a different problem to be solved by the present invention.

The first object of the present invention is to provide a soft X-ray generator for irradiation provided with an X-ray irradiation reference room which is excellent in safety.
The purpose is. A second object of the present invention is to provide a soft X-ray generator for irradiation provided with a high-frequency power supply capable of realizing a stable X-ray dose rate with a large X-ray dose. Further, a third object of the present invention is to provide a soft X-ray generator for irradiation provided with a cooling device capable of continuously irradiating X-rays for a long time.

[0009]

SUMMARY OF THE INVENTION The first object of the present invention is to provide an apparatus main body having an X-ray tube arranged in an X-ray irradiation reference room, and a high-pressure drive stabilized with respect to the X-ray tube. An irradiation soft X-ray generator including a high-frequency power supply device for supplying power and a cooling device for cooling the X-ray tube, wherein the device main body includes a completely hermetic X-ray irradiation box; A wide-angle X-ray tube for irradiating X-rays in a conical shape from the ceiling to the bottom in the box, a document mounting table arranged at a position where the X-rays are irradiated inside the box, and an inside of the box A soft X-ray generator for irradiation, comprising: a door that can be opened and closed to put materials into and out of the X-ray tube, and when the door is opened, the power supply unit cuts off driving power to the X-ray tube. Can be achieved.

[0010] The second object of the present invention is to provide an apparatus body having an X-ray tube disposed in an X-ray irradiation reference room, and a high-frequency power supply for supplying a stabilized high-voltage drive power supply to the X-ray tube. A soft X-ray generator for irradiation including a device and a cooling device for cooling the X-ray tube, wherein the high-frequency power supply device includes:
A circuit board that operates on an AC commercial power supply, drives a boost transformer with a high-frequency signal, rectifies the output of the boost transformer, and further boosts the voltage to generate a stabilized DC high voltage;
This can be achieved by a soft X-ray generator for irradiation including a power control unit for controlling the output of the circuit board to drive the X-ray tube.

A third object of the present invention is to provide an apparatus body having an X-ray tube disposed in an X-ray irradiation reference room, and a high-frequency power supply for supplying a stabilized high-voltage driving power supply to the X-ray tube. A soft X-ray generator for irradiation comprising a device and a cooling device for cooling the X-ray tube, wherein the cooling device comprises:
This can be achieved by an irradiation soft X-ray generator including an electronic unit cooler that directly cools the cooling oil of the wire tube and a pump that circulates the cooling oil of the cooler.

According to a preferred embodiment of the present invention, all means for achieving the first to third objects can be applied to one irradiation soft X-ray generator. In this case, it is preferable that the material mounting table is rotatable in order to uniformly irradiate the material with X-rays. Other objects, configurations, and effects will be clarified in embodiments described later.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to embodiments shown in the drawings. FIG. 1 (A), (B)
(C) is a front view, a side view, and a rear view showing an embodiment of the soft X-ray generator for irradiation according to the present invention. FIG.
(A) and (B) are the side view and top view which show the X-ray irradiation area of FIG. FIG. 3 is a system diagram showing the low-pressure and high-pressure wiring systems for X-ray generation and the circulating oil system for X-ray tube cooling of FIG.

The irradiation soft X of the present invention shown in these figures
The X-ray generator is roughly divided into an X-ray tube main body in which an X-ray tube is arranged in an X-ray irradiation reference room, a high-frequency power supply for supplying a stabilized high-voltage drive power to the X-ray tube,
A cooling device for cooling the wire tube.

The main body of the apparatus comprises a completely sealed X-ray irradiating box (cabinet) 1 and a wide-angle X-ray tube 5 for irradiating X-rays from the ceiling to the bottom in the box 1. And a radiation table door 2 which can be opened and closed for taking data in and out of the box 1. Is opened, the drive power supply to the X-ray tube 5 is cut off by the power supply device. One material placing table 7 is a material rotating table, and the other material placing table 11 is a material shelf board. In addition, an irradiation room viewing window 3, an X-ray operation panel 4, and an X-ray tube container 17 containing the X-ray tube 5 are provided.

The high-frequency power supply device is operated by an AC commercial power supply, drives a step-up transformer with a high-frequency signal, rectifies the output of the step-up transformer, and further boosts the circuit to generate a stabilized DC high voltage. The board 6 and the circuit board 6
And a power control unit 8 configured on a substrate for controlling the output of the X-ray tube 5 to drive the X-ray tube 5. The circuit board 6 and the power control unit 8 are connected by a 4-core connection cable 9 and a 16-core connection cable 10. Circuit board 6
Is housed in the X-ray tube container 17 and the power control unit 8
Are stored in the high-frequency power supply substrate storage box 16.

The cooling device includes an electronic unit cooler 13 for directly cooling the cooling oil of the X-ray tube 5 and an oil circulation gear pump 15 for circulating the cooling oil of the cooler 13. In addition, an oil circulation hose 12 that connects the X-ray tube container 17, the cooler 13, and the pump 15 and a cooling fan 14 that cools the cooler 13 are provided.

In the irradiation room of the X-ray prevention box 1,
Turntable 7 below X-ray tube 5 arranged at the center of the ceiling
2, a conical X-ray 20 is emitted as shown in FIG. The X-ray 20 shown in this figure is 100 mm in diameter at a distance of 150 mm from the X-ray tube 5 and 20 mm in diameter at a distance of 280 mm.
It has a conical shape with a diameter of 300 at 0 mm and a distance of 400 mm. An unillustrated material (object to be irradiated) is placed on the turntable 7 and irradiated with the X-rays 20. At this time, turntable 7
Is rotated, the amount of X-ray irradiation on the material is made uniform.

The materials are as follows. Open the door 2 of the irradiation room,
Set on top. When this door 2 is completely closed, X-ray 2
Numeral 0 denotes a completely sealed X-ray protection structure which does not leak to the outside of the box 1 even during radiation. For this reason, the present device has a safety that does not require consideration of the surrounding X-ray control area. Also,
If the door 2 is opened while the X-rays 20 are being emitted, the X-rays are controlled to be stopped instantaneously, so that the safety is further enhanced.
Further, since the double safety interlock system is applied so that X-rays cannot be emitted unless the door 2 is completely closed, the safety is high. Therefore, the operation of the apparatus does not require the qualification of the chief of X-ray work.

Incidentally, the Ministry of Labor's Ionizing Radiation Prevention Regulations No. 2
The legally acceptable figures for external X-ray leakage stipulated in Chapter 3,
The external radiation dose is 0.3 mSv or less per week, but according to the structure of the present apparatus, it is easy to suppress the external X-ray leakage value to about 1/10 of that. For this reason, the box 1 is, for example, 500 mm wide, 600 mm deep,
The steel plate and the lead plate are designed to have a height of 800 mm and have a thickness that does not cause external X-ray leakage exceeding the above-mentioned value even when the maximum tube voltage is used.

The X-ray tube 5 is provided with a special beryllium window at an emission port, and can obtain a large amount of X-rays having a long X-ray wavelength suitable for irradiation used in a low tube voltage range of 100 kVp or less, that is, soft X-rays. It is like that. Further, in order to widen the effective irradiation area, for example, a wide-angle X-ray tube 5 having a radiation angle of about 40 degrees is used.

The inside of the X-ray tube container 17 containing the X-ray tube 5 is filled with insulating and cooling oil, and the oil is circulated between the lower unit cooler 13 and the X-ray tube. The heat associated with the X-ray irradiation of the tube 5 is recovered and cooled.

The high-frequency power supply described above is used as a high-voltage generator for generating X-rays. This power supply device operates on a commercial power supply of AC 100 V, 50/60 Hz, and drives the step-up transformer at a high frequency of about 40 KHz.
Then, the output of the transformer is rectified to a DC voltage and then further boosted, and an output of maximum 100 KV and 250 W is applied to the X-ray tube 5. The high-frequency power supply circuit board 6 constituting a part of this power supply device performs boosting, rectification, and feedback signal detection. On the other hand, the power control unit 8, which constitutes the rest of the power supply device, performs power and voltage stabilization, power supply abnormality protection, tube voltage control, and tube current control.

To give specific numerical values, for a large X-ray dose required for X-ray irradiation, the stability of the X-ray dose rate at a tube voltage of 5 mA or more is as follows. Current stability within ± 2%,
Ripple is 3KV or 3% or less.

In comparison with the conventional rectification methods of self-rectification (half-wave rectification) and full-wave rectification (double-wave rectification), the high-frequency power supply of the present invention employs smoothing rectification combining a capacitor and a rectifier. Thus, it becomes possible to increase the X-ray generation rate at the same tube current and tube voltage as those of the two conventional methods by about 1.5 times.

The cooling device of the present invention comprises an electronic unit cooler 13 for directly cooling the cooling oil of the X-ray tube 5, and an oil circulation gear pump 15 for circulating the cooling oil of the cooler 13. The bulb 5 can be used continuously for a long time. Electronic unit cooler 13
Is an assembly of a thermo module (cooling element), a heat absorbing plate (cooling plate), a radiator (fin), and a radiating fan motor.

The electronic unit cooler 13 is designed to be compact and consume less power in consideration of thermal contact, heat radiation area, moisture proof, heat insulation and the like. Since the electronic unit cooler 13 using the thermo module does not require the liquid or gas of the refrigerant which has been conventionally required, it does not have a rotating friction part and is directly mounted on the device of the present invention as a cooling device requiring no maintenance. And contribute to downsizing of the entire device.

Specifically, the circulation gear pump 15 is
The oil temperature can be maintained at 40 ° C. or less by installing the hose between the wire tube container 17 and the electronic unit cooler 13 and circulating the oil during use of the apparatus. For this reason, it is possible to continuously use a large X-ray for a long time.

The X-ray operation panel 4 clarifies the management by operating the power key switch.
Notifies that radiation is being emitted. The X-ray irradiation time can be automatically set by a digital timer. The state of the material inside the box 1 receiving X-ray irradiation can be observed through the viewing window 3 of the material room protected by lead-containing glass. Turntable 7
The shelves 11 are selectively used according to the type and amount of the material.
Soft X-ray photography can also be performed in the irradiation room.

FIG. 4 is an enlarged front view showing the X-ray operation panel 4. The X-ray operation panel 4 includes two left and right X-ray emission display lamps 41 illuminated during X-ray irradiation, a tube voltmeter 42 for displaying a tube voltage value, and a tube ammeter 43 for displaying a tube current value.
And digital timer 4 for irradiation to set X-ray irradiation time
4, a tube voltage adjustment knob 45 for setting a tube voltage value, a tube current adjustment knob 46 for setting a tube current value, and a power key switch 47 for switching on / off the apparatus power.

Other indicator lamps include a power indicator lamp 51 which is turned on when the power is turned on, and an indicator lamp which is turned on when the temperature of the cooling oil in the X-ray tube container 17 exceeds a set value due to continuous use for a long time or the like. X-ray tube container temperature alarm lamp 5
2, a door interlock display lamp 53 that lights up when the door 2 is open, an X-ray emission display lamp 54 that lights up during X-ray emission, and a light that turns on when any abnormality occurs in the X-ray tube 5 (X X-ray tube abnormal alarm lamp 5
5 are provided.

[0032]

As described above, according to the present invention, a soft X-ray for irradiation which is excellent in safety, can realize a stable X-ray rate at a large X-ray dose, and can continuously irradiate X-rays for a long time. A line generator can be provided. In particular, regarding X-ray irradiation, not only the quality of X-rays but also tube voltage, tube current, irradiation time, irradiation distance, etc. for obtaining appropriate irradiation X-rays can be arbitrarily controlled. Without the need for a controlled area, and without the qualification of the chief of X-ray work,
Further, it is possible to realize a soft X-ray generator for irradiation having general versatility that can be used even on a desk because it is lightweight and small. For this reason,
In the field where X-ray irradiation is used more and more especially in the field of biotechnology, it is expected that the frequency of use according to the purpose will increase in many fields.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of a soft X-ray generator for irradiation according to the present invention.

FIG. 2 is an explanatory diagram showing an X-ray irradiation area of the apparatus of FIG.

FIG. 3 is a system diagram showing a power supply device and a cooling device of FIG. 1;

FIG. 4 is an enlarged front view showing the X-ray operation panel of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 X-ray prevention radiation box 2 Irradiation room door 3 Irradiation room viewing window 4 X-ray operation panel 5 X-ray tube 6 High frequency power supply circuit board 7 Data rotation board 8 High frequency power supply power control unit 9 Connection cable 10 Connection cable DESCRIPTION OF SYMBOLS 11 Material shelf board 12 Oil circulation hose 13 Cooling electronic unit cooler 14 Cooling fan 15 Oil circulation gear pump 16 Substrate storage box for high frequency power supply 17 X-ray tube container 20 X-ray

Claims (4)

[Claims] 1. An apparatus main body having an X-ray tube arranged in an X-ray irradiation material chamber, a high-frequency power supply for supplying a stabilized high-voltage driving power to the X-ray tube, and the X-ray tube A soft X-ray generator for irradiation comprising a cooling device for cooling the X-ray irradiation device, wherein the main body of the device is a completely sealed X-ray protection box, and the X-ray is conical from the ceiling to the bottom in the box. A wide-angle X-ray tube for irradiating rays, a material mounting table disposed at a position where the X-rays are radiated inside the box, and a door that can be opened and closed for taking data in and out of the box. When the door is opened, the driving power supply to the X-ray tube is shut off by the power supply device. 2. An apparatus main body in which an X-ray tube is arranged in an X-ray irradiation data chamber, a high-frequency power supply for supplying a stabilized high-voltage driving power to the X-ray tube, and the X-ray tube A high-frequency power supply device that operates with an AC commercial power supply to drive a step-up transformer with a high-frequency signal, and rectifies the output of the step-up transformer. And a power control unit for controlling the output of the circuit board to drive the X-ray tube. X-ray generator. 3. An apparatus main body in which an X-ray tube is arranged in an X-ray irradiation data chamber, a high-frequency power supply for supplying a stabilized high-voltage driving power to the X-ray tube, and the X-ray tube A soft X-ray generator for irradiation, comprising: an electronic unit cooler for directly cooling oil for cooling the X-ray tube; and a cooling device for cooling the oil for cooling the X-ray tube. A soft X-ray generator for irradiation, comprising: a circulating pump. 4. The soft X-ray generator for irradiation according to claim 1, wherein the sample mounting table is rotatable.