KR20000019824A - Multi target apparatus for beam irradiation - Google Patents

Abstract

PURPOSE: A multi target apparatus for a beam irradiation is provided to generate plural nuclidesus by running up and down plural target irradiation parts installed at a frame, and to prevent air from being contaminated radioactively by closely attaching a beam transfer pipe to a target irradiation part. CONSTITUTION: A plurality of target irradiation parts(10) generating a radioactive isotope as a beam passes through are installed at a frame(111). The frame is connected with a plate(112), and a ball screw(131) and a motor(132)run the plate up and down such that one of the target irradiation parts is located at a beam line passed through the beam path. A cylinder(121) and a guide bar(122)moves the frame forward and backward such that the target irradiation part at the beam line is closely attached to the beam path. A movement of the target irradiation parts exactly controlled by a limit switch(141).

Description

Multi-targeting device for beam irradiation for radioisotope production

The present invention relates to a multi-targeting device for beam irradiation for the production of radioisotopes, and more particularly, it is possible to produce a plurality of nuclides while raising and lowering by installing a plurality of target irradiation unit in one frame, radioactive isotope harmful to the human body The target irradiator can be brought into close contact with the beam passage so that no elements are generated.

In general, radioisotope (R.I.) is widely used in medicine, biology, engineering, agriculture, and other fields, and domestic consumption is increasing every year.

These radioisotopes are largely classified into reactor nuclides and accelerator nuclides. The nuclear reactor is a neutron surplus nucleus, while the accelerator nuclide is a neutron deficient nuclide. The nuclear properties of these nuclides are complementary, and nuclear reactors are used primarily for therapeutic purposes, while accelerator nuclides are used for diagnostic purposes.

Accelerator nuclides, unlike nuclear reactor nuclides, not only have a high specific activity of the non-carrier, but also collapse due to electron capture or positron (β ⁺ ) emission, which significantly reduces the radiation exposure to patients. In nuclear medicine, accelerator nuclides are more preferred because they provide clearer images. In other words, most nuclear reactors emit β, which is used for medical treatment, while accelerator nuclides emit β ^+, and thus are used in diagnostic or positron emission tomography (PET).

Moreover, positron-emitting nuclides are used in PET to study metabolism in humans, diagnose cancer, diagnose heart failure, and diagnose various diseases caused by abnormalities of the nervous system.

For medical use of such radioisotopes, consideration should be given to the following depending on the physical, chemical and biological characteristics of the nuclide.

(1) Minimum radiation exposure of patient

(2) suitable γ-ray energy for obtaining high resolution

(3) high specific radioactivity

(4) ubiquitous rate for specific organs

(5) ease of use

(1) is the physical properties of the isotope, that is, the amount of exposure due to the decay method, radioactivity should be small, (2) is depending on the characteristics of the radioactivity measuring device, the half-life is short and the γ-ray of about 60KeV to 300KeV is suitable. In the case of emitting a single γ-ray, high resolution images can be obtained with a single photon emission computed tomography (SPECT). In addition, α-particles and isotopes that emit large energy β-particles are used for treatment because they expose a lot of radioactivity to the local area.

The high specific radioactivity of (3) (4) and ubiquitous specific organ are criteria for selecting isotopes to be used for studying metabolism in vivo, and these isotopes are covalently bound to compounds in vivo and thus It should be stable. (5) above shows the ease of use of isotopes in the wide area. If the half-life of the isotope is short and the transportation time is long, a generator system can be developed and used.

Based on these criteria, about 50 nuclides are currently used for medical purposes, and these nuclides are generally classified into seven types.

(1) Organic short-lived β ⁺ emitters: ¹¹ C, ¹³ N, ¹⁵ O, ¹⁸ F and the like.

(2) Halogens: ¹⁸ F, ⁷⁵ Br, ⁷⁷ Br, ¹²³ I and the like.

(3) Rare Gases: ⁷⁷ Kr, ¹³³ Xe and the like.

(4) Generator systems: ⁶⁸ Ge → ⁶⁸ Ga, ⁸² Sr → ⁸² Rb, ²⁰¹ Mo → ^99m Tc, ⁸¹ Rb → ⁸¹ Kr

(5) Alkali and alkali like metals: ³⁸ K, ⁸² Rb, ²⁰¹ Tl and the like.

(6) Inorganic radionuclides: ⁵² Fe, ⁶⁷ Rb, ¹¹¹ In, ⁵⁵ Co, ⁸⁵ Sr and the like.

(7) Therapeutic radionuclides: ⁷⁷ Br, ¹²⁵ I, ²¹¹ At and the like.

Cyclotron for producing such nuclides was used mainly in nuclear physics research in the early 1930s, and began to be used for the production of medical radioisotopes in the 1960s. Neutron treatment with cyclotron and radioisotope production began for the first time in 1955, and commercial production began in the 1970s due to increased demand for accelerator nuclides due to the development of nuclear medicine. In particular, at the end of 1980, anion cyclotrons were developed and used to facilitate beam extraction and acceleration energy conversion.

The radionuclide production by the cyclotron described above is a production condition depending on the characteristics of the cyclotron beam and the type of target material. In other words, consideration should be given to the type of particles to be irradiated to the target material, the selection of appropriate nuclear reactions, the determination of the optimal energy range to maximize the yield of the minimum amount of impurities and the desired isotope, the cooling capacity of the target material and the strength of the particle current. do. Also, in isotope production, the expected yield is proportional to the particle current. In other words, the isotope production yield is directly proportional to the intensity of the beam current.

Conventional beam irradiation target apparatus for producing a radioisotope is composed of a collimator installed in the beam path to which the beam is irradiated to produce a radioisotope, and a target irradiation unit irradiated with the beam passing through the collimator.

However, since the conventional target device is composed of one target irradiator, only one nuclide can be produced at a time, and in order to produce another nuclide, a new target irradiator must be replaced every time, resulting in a lot of inconveniences in replacing and replacing a plurality of target devices. There was a problem such as the inefficient production of nuclides.

An object of the present invention has been invented to solve such a problem, it is possible to produce a plurality of nuclides while raising and lowering by installing a plurality of target irradiation unit in one frame, the target irradiation unit so that harmful radioisotopes are not generated to the human body The present invention provides a multi-targeting apparatus for beam irradiation for producing radioisotopes, which is configured to be in close contact with the beam path, thereby simplifying the replacement of the target irradiation unit.

1 is a block diagram of a target irradiation unit for the production of radioisotopes

2 is a side view of a multi-targeting device according to the present invention;

3 is a front view of the multi target device according to the present invention;

4 is a cross-sectional view taken along the line IV-IV of FIG. 3.

5 is a cross-sectional view taken along the line VV of FIG.

6 is a cross-sectional view taken along the line VI-VI of FIG. 3.

-Explanation of symbols for the main parts of the drawing-

10-Target Survey 111-Frame

112-Plate 121-Cylinder

122-Guide Bar 123-Spring

131-Ball Screw 132-Motor

141-limit switch 142-encoder

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

In the configuration of the multi-targeting apparatus for beam irradiation for radioisotope production according to the present invention, as shown in FIGS. 1 to 6, the beam irradiated through the beam passage is irradiated to produce a radioactive isotope 10. Is provided with a plurality of frames 111, the plate 112 to which the frame 111 is coupled, and one target irradiator 10 of the plurality of target irradiator 10 is located in the beam line passing through the beam passage Elevating means for elevating and lowering the plate 112, forward and backward means for advancing and retreating the frame 111 so that the target irradiator 10 positioned in the beam line is in close contact with the beam path, and the plurality of target irradiators 10 ) Is configured to control to control the lifting up and down at regular intervals.

The target irradiator 10 includes a connector 12 connected to the vacuum valve 30, a target chamber 11 inside a vacuum state, and a cooling unit cooling the target chamber 11. .

By installing a plurality of such target irradiation unit 10 to produce a plurality of nuclides, it is possible to produce a plurality of radioisotopes in one target irradiation device.

The lifting means consists of a ball screw 131 coupled to both sides of the plate 112, and a motor 132 for rotating the ball screw 131, the ball screw installed on both sides of the plate (112) A timing belt 133 is provided to rotate the 131 at the same time, and the timing belt 133 is coupled to the timing pulley 134. In addition, an encoder 142 for controlling the rotation of the ball screw 131 is installed below the ball screw 131.

The forward and backward means includes a cylinder 121 installed at the rear of the frame 111 to advance the frame 111, a guide bar 122 for guiding the frame 111 advanced by the cylinder 121, and It is composed of a spring 123 is coupled to the outer circumference of the guide bar 122 to restore the advanced frame 111.

The control means includes a plurality of limit switches 141 provided at one side of the plate 112 to be moved up and down, and a protrusion piece 111a protruding from the plate 112 to operate the limit switch 141. Is done.

According to the present invention configured as described above, the radioactive isotope is irradiated to the target irradiator 10 through the collimator 20 to produce the radioisotope. At this time, the passage of the beam irradiated through the collimator 20 is constant, and the plurality of target irradiator 10 is raised and lowered so that one target irradiator 10 is positioned to produce several nuclides.

In this way, the operation for raising and lowering the target irradiation unit 10, when the power is first applied to the motor 132, the ball screw 131 is rotated, the rotation of the ball screw 131 The plate 112 is moved up and down by this.

When the plate 112 that is raised and lowered as described above is lifted by a predetermined distance, the protruding piece 111a protruding from the plate 112 operates the limit switch 141 to stop the driving of the motor 132.

Accordingly, the plate 112 is stopped at the correct position and at the same time one target irradiator 10 of the plurality of target irradiators 10 is positioned in the beam path. At this time, the target irradiator 10 is accurately positioned in the beam path to produce a nuclide.

As such, when one target irradiator 10 is positioned in the beam path, the rod 121 ′ of the cylinder 121 is advanced to advance the frame 111 on which the plurality of target irradiators 10 are installed to closely contact the beam path. As a result, the irradiated beam does not nuclearly react with the air particles, thereby preventing radioactive contamination of the air particles.

That is, the connector 12 of the target irradiator 10 advanced by the cylinder 121 is in close contact with the air, so that the connector 12 must be in a vacuum state so that the irradiated beam does not nuclearly react with air particles. Will not. As such, a vacuum pump (not shown) is operated to vacuum the connector 12 in order to vacuum the connector 12.

When the target irradiation unit 10 is replaced as described above, first, the target irradiation unit 10 is replaced with the collimator 20 on the side where the vacuum valve 30 is closed to keep the vacuum state continuously, and the vacuum valve ( 30 may be opened only after the connector 12 is vacuumed to prevent the irradiated beam from nuclear reaction with the air particles, thereby preventing radioactive contamination of the air particles.

As such, the frame 111 advanced by the cylinder 121 is elastically advanced by the spring 123 installed on the outer circumference of the guide bar 122. Therefore, after the radioactive isotope is produced in one target irradiator 10, the rod 121 ′ of the cylinder 121 is reversed, and the frame 111 is restored by the elastic force of the spring 123. .

In this state, when the motor 132 is driven again, the plate 112 is moved up and down again so that the target irradiator 10 provided with another target is positioned in the beam path to produce another nuclide.

As can be seen from the above description, according to the multi-targeting apparatus for beam irradiation for producing the radioisotope of the present invention, by installing a plurality of target irradiation units in one frame, it is possible to produce several nuclides while raising and lowering the target irradiation unit. Reduces the cost of production, and has the effect of simplifying the use. In addition, the target irradiation unit is in close contact with the beam passage, and by vacuum using a vacuum pump, there is an effect that can prevent radioactive contamination of air particles.

Claims (4)

A frame provided with a plurality of target irradiation units for irradiating beams passing through the beam passages to produce radioisotopes; A plate to which the frame is coupled; Elevating means for elevating and lowering the plate such that one of the plurality of target irradiation units is positioned in the beam line passing through the beam passage; Forward and backward means for advancing and retreating the frame such that the target irradiator positioned in the beam line is in close contact with the beam path; Multi-targeting apparatus for beam irradiation for radioisotope production, characterized in that the control means for controlling the plurality of target irradiation unit to move up and down at a predetermined interval accurately. The multi-target apparatus for beam irradiation for radioisotope production according to claim 1, wherein the elevating means comprises a ball screw coupled to both sides of the plate, and a motor for rotating the ball screw. According to claim 1, wherein the forward and backward means is a cylinder installed on the back of the frame to advance the frame, a guide bar for guiding the frame advanced by the cylinder, and coupled to the outer periphery of the guide bar to restore the advanced frame Multi-targeting device for beam irradiation for radioisotope production, characterized in that consisting of a spring to make. According to claim 1 or claim 2, wherein the control means is a plurality of limit switches provided at one side of the plate to be moved up and down and a plurality of limit switches, characterized in that the protrusion pieces protruding on the plate to operate the limit switch Multi-targeting device for beam irradiation for radioactive isotope production.