CN1139940C

CN1139940C - Cobalt 60-gamma ray dot source device

Info

Publication number: CN1139940C
Application number: CNB011070838A
Authority: CN
Inventors: 萧祖贻; 焦景凡; 萧冰
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-01-31
Filing date: 2001-01-31
Publication date: 2004-02-25
Anticipated expiration: 2021-01-31
Also published as: CN1314679A

Abstract

The present invention relates to a Cobalt 60-gamma ray dot source device which belongs to the field of the application of nuclear radiation, and the present invention is a novel product which has the advantages of favorable shielding and safe and convenient use. A pulse equivalent weight is transmitted to a stepper motor 1 by a computer, bevel gear pairs 2 and 3 are driven by a motor shaft, movement is transmitted to a rotating shaft 4 by deceleration, a lean uranium inner ball shielding body 5 is driven to make a gamma dot source 6 arranged on the lean uranium inner ball shielding body 5 lie in an operation position by the rotating shaft 4, and rays are emitted from a collimator; if the shaft 4 rotates 180 degrees, the gamma dot source 6 is positioned on the shielding position of the central position O' of outer ball shielding bodies 8 and 9. The device is mainly used for ICT (Industrial Computer Tomography), a modified type of the device can be used for the fields of the flaw detection of an industrial structure, the liquid level control of a steel vessel and a chemical vessel, etc.

Description

60The Co-gamma ray dot source device

Technical field: the present invention " ⁶⁰The Co-gamma ray dot source device " technology relate to nuclear radiation application branch of learning field.

Background technology:

In isotopic radiographic source, only just be most widely used ⁶⁰Co-γ source, the present document of grasping show, no matter the technology and equipment of preparation, transportation, upside-down mounting, deposit and the application in γ source all obviously falls behind.For example transport four in a kind of pen type source from Canada, size is about Φ 14 * 350mm, packs with 6 tons pig shielding unexpectedly, and upside-down mounting work is still carried out at the deep well more than 8 meters with long clamp.Some device is also very ancient, when needing the work of γ source, still with the method for directly opening the pig lid or uncapping with simple mechanism, inconvenient operation but also be absolutely unsafe not only, usually bring the danger of super metering radiation injury to operating personnel, more can not reach the accuracy requirement of detection to the source, the nuclear radiation accident that takes place on China Shanghai, Sichuan, Heilungkiang and other places all has a large amount of reports on the document.①②③

The purpose of the present invention's development promptly is to be ICT (Industrial Computer Tomography.In translated name: the industrial computed tomography imaging device), provide a kind of advanced person, high-precision, safe and reliable, easy to operate γ dot source device is looked into new conclusion and is shown that the present invention does not have identical document and patent report at home, 4. 5. 6. 7. 8..

Summary of the invention: the present invention is achieved by the following technical solutions:

As schematic diagram 1, and accompanying drawing 2, Fig. 3, Fig. 4, the major technique feature of this device is: adopting with the depleted uranium is two ball shield structures of material.

Outer ball shield

8,9, on the radius of optical collimator 7 directions, the mid point of crown radius is center of circle O ' in addition, 1/2 of the exradius of

ball shield

8,9 is radius in addition, forms the spherical pore of ball shield 5 in the dressing.Because assembling and arts demand, the vertical located of the spherical pore center of circle O ' of

ball shield

8,9 is divided into forward and backward two halves outside, outer ball shield 8 and back outer ball shield 9 before being called, in packing into behind the ball shield 5, aim at anti-radiation leakage seam, with 6 bolts 14, with forward flange 12, rear flange 13, preceding outer ball shield 8, the outer ball shield 9 in back is assembled into an integral body.The front end of ball shielding 8 is equipped with optical collimator 7 outside preceding.Interior ball shield 5, be contained on the axle 4 with flat key 15, two ends with axle 4, be contained in respectively on two thrust ball bearings 22, thrust ball bearing 22 is contained in respectively on shell 21 and the bearing bridge 20, the input end of axle 4 is equipped with bevel gear wheel 3 with flat key 16, bevel gear wheel 3 is meshed with the bevel pinion 2 of the axle head that is fixed on stepper motor 1 with flat key 17, so just, be implemented in by the stepper motor output speed, by speed ratio is i=1/2, interior ball shield 5 is passed in motion, to realize the conversion of mask bit and working position.More than inside and outside ball shield assemble the back and be fixed on the base 23 with the bearing bridge 20 of interior ball shield, promptly finish the integral body assembling of γ dot source device.This crust of the device 21 usefulness corrosion resistant plates are packed, and shield the faint radiation of depleted uranium.

The motion of this device is achieved in that when being responsible for the ICT complete machine computer PC of control automatically, temporal information and the pulse equivalency set are transferred to stepper motor 1, the bevel pinion 2 that is contained in the stepper motor axle head is meshed with bevel gear wheel 3 on being contained in axle 17, to move with speed ratio i=1: 2 reductions of speed are passed to interior ball shield 5, use press fit to be fixed on the γ point source of interior ball shield like this, realize the conversion of working position and screening-off position, when the γ point source goes to the cylindrical point of contact O ' (being the center of optical collimator) of inside and outside circle shield is the working position of γ point source, when the center O of rotating 180 ° of ball shields outside the γ point source goes to " time be screening-off position.

Advantage of the present invention is that shielding properties is reliable, compact conformation, and the positional precision height in source is easy to operate, meets the requirement of international source apparatus.

Description of drawings:

Fig. 1, principle schematic Fig. 5, γ point source structural drawing

Fig. 2, front view

Fig. 3, vertical view

Fig. 4, left side partial cutaway schematic

Embodiment 1; Introduce the example that the present invention uses below on first batch of National Torch Plan project ICT (industrial computed tomography imaging) model machine.

Above each figure is described as follows as drawing: on the excircle of ball shield 5, the position on Fig. 2 front view was the working position of γ point source 6 in the 6 usefulness press fits of γ point source were assemblied in, and ray penetrates and works from optical collimator 7.Optical collimator 7 is screwed on the end face of ball shield 8 outside preceding.Interior ball shield 5 rotates 180 °, and 6 of γ point sources are in the center O of

outer ball shield

8,9 " locate, realize masked state.Above motion realizes according to the following steps: computing machine is transferred to stepper motor 1 with the pulse equivalency of setting and drives the bevel pinion 2 that is fixed on the output axle head with flat key, again motion is passed to flat key and be fixed on the bevel gear wheel 3 of axle on 4,3 with speed ratio I=1: 2 deceleration is passed to motion axle 4 and is fixed on interior ball shield 5 on this with flat key, 5 drive 6

ball shield

8,9 transmissions to foreign round mutually of γ point source, realize the conversion of γ point source 6 working positions or mask bit.

The repeatable accuracy that γ point source 6 circumference rotate was divided into for two steps and realizes, at first was with mechanical spring register pin 10, acted in the taper hole of bevel gear wheel 3 and realized pre-determined bit, and then the precision that can be controlled by pulse equivalency is made fine positioning.γ point source 6 is with respect to the exact position of all detector on the ICT complete machine detector display---and this position promptly guarantees the background numeration error of each detector reception information in the allowed band of complete machine error distribution, and it is to be realized by the three-dimensional fine setting piezoelectric crystal of external coordination development.Same structure is not installed with this by this mechanism, is omitted at this.

Primary clustering is as follows:

1, ⁶⁰The Co-source component: active nose bar cun position Φ 4 * 4mm, physical dimension Φ 6 * 8mm, source strength 50Ci (Curie), shell are the stainless steel packing, see Fig. 5, its structure is described as follows: 31 are ⁶⁰CO; 32 is Stainless Steel Shell; 33 is pad; 34 is gland.

2, shield assembly: the 6 usefulness press fits of γ point source are assemblied on the circumference of interior ball shield, the diameter of interior ball shield is about 1/2 of

outer ball shield

8,9 diameters, its assembly center is positioned at 1/2 place of

outer ball shield

8,9 horizontal direction radiuses, interior ball shield is 8,9 rotations of ball shielding to foreign round mutually as the center, three grade packaged requirements are calculated according to national standard, the cylindrical bulb diameter is 210mm, and interior ball diameter is 110mm.

3, optical collimator 7: its effect is the fladellum that forms certain altitude and width, the high 2mm in hole, and wide 4mm, segment angle are benchmark with the horizontal center line, see Fig. 1, α ₁=48 °, α ₂=59.5 °, material is a tungalloy, is fixed on the front end face of outer ball shield 8.

The major parameter table

Sequence number	Title	Technical parameter
Sequence number	Title	Technical parameter	1	Radioactive source	Material ⁶⁰CO point source, ray γ, source strength 50Ci, active region size Φ 4 * 4mm
2	Interior cylindrical shield body	Diameter of phi 110mm; Material: depleted uranium: density 18.75g/cm ³	1	Radioactive source
2	Interior cylindrical shield body		3	The outside cylinder shield	Diameter of phi 210mm; Material: depleted uranium: density 18.75g/cm ³
4	Optical collimator	Hole height * wide=2 * 4mm, fan angle alpha ₁＝48°，α ₂=59.5 °, material: tungalloy	3	The outside cylinder shield
4	Optical collimator		5	Stepper motor	Model 86BYG001, diameter of axle Φ 9.5mm, 4 phases, 1.8 ° of stepping angles, error ± 0.18 °
6	Source revolution bearing accuracy	Machinery pre-determined bit ± 0.20mm, automatic control location 0.05mm	5	Stepper motor
6	Source revolution bearing accuracy		7	Position, source three-phase trimming precision	Range 1mm, trimming precision ± 0.005～± 0.01mm (choosing wantonly)
8	Radiation safety dosage	Less than 200mr/h, meet country's three grade packaged standards	7	Position, source three-phase trimming precision
8	Radiation safety dosage		9	Overall dimensions	475×300×273mm
10	Weight	≈150Kg	9	Overall dimensions	475×300×273mm

Claims

1, a kind of " ⁶⁰The Co-gamma ray dot source device "; it is characterized in that: adopting with the depleted uranium is two ball shield structures of material; outer ball shield (8); (9); on the radius of optical collimator (7) direction; the mid point of crown radius is center of circle O ' in addition, ball shield (8) in addition, (9) 1/2 of exradius is a radius, form the spherical pore of ball shield (5) in the dressing, because assembling and arts demand, ball shield (8) outside, (9) vertical that spherical pore center of circle O ' locates, before being divided into, back two halves, outer ball shield (8) and back outer ball shield (9) before being called, in packing into behind the ball shield (5), aim at anti-radiation leakage seam, with 6 bolts (14), with forward flange (12), rear flange (13), preceding outer ball shield (8), back outer ball shield (9), be assembled into an integral body, the front end of ball shield (8) is equipped with optical collimator (7) outside preceding, interior ball shield (5), be contained on the axle (4) with flat key (15), with the two ends of axle (4), be contained in respectively on two thrust ball bearings (22), thrust ball bearing (22) is contained in respectively on shell (21) and the bearing bridge (20), the input end of axle (4) is equipped with bevel gear wheel (3) with flat key (16), bevel gear wheel (3) is meshed with the bevel pinion (2) of the axle head that is fixed on stepper motor (1) with flat key (17), so just is implemented in by the stepper motor output speed, and be i=1/2 by speed ratio, interior ball shield (5) is passed in motion, to realize the conversion of mask bit and working position.

2, according to claim 1 " ⁶⁰The Co-gamma ray dot source device ", it is characterized in that: on the excircle of ball shield (5), according to national standard radiation source three grade packaged criterion calculation, the cylindrical bulb diameter was 210mm in γ point source (6) was contained in press fit, and interior ball diameter is 110mm.

3, according to claim 2 " ⁶⁰The Co-gamma ray dot source device ", it is characterized in that: the density of material of depleted uranium is 18.75/cm ³

4, according to claim 3 state " ⁶⁰The Co-gamma ray dot source device ", it is characterized in that the structure of γ point source: in the γ point source, in the Stainless Steel Shell (32) ⁶⁰Co (31) is covered by gland (34), ⁶⁰Co (31) is by pad (33) is arranged between the gland (34).