US3259747A

US3259747A - Apparatus for recording an image of the local distribution and the radiation intensity of radioactive materials deposited in a space

Info

Publication number: US3259747A
Application number: US308030A
Authority: US
Inventors: Ziegler Albert
Original assignee: Siemens AG
Current assignee: Siemens Schuckertwerke AG; Siemens AG
Priority date: 1962-09-21
Filing date: 1963-09-10
Publication date: 1966-07-05
Anticipated expiration: 1983-07-05

Description

July 5, 1966 A. ZIEGLER 3 ,7 7

APPARATUS FOR RECORDING AN IMAGE OF THE LOCAL DISTRIBUTION AND THE RADIATION INTENSITY OF RADIOACTIVE MATERIALS DEPOSITED IN A SPACE Filed Sept. 10, 1963 2 Sheets-Sheet 1 Fig.1

July 5, 1966 A. ZIEGLER 3,259,747

APP '1' FOR ORDING AN IMAGE OF TH OCAL DISTRIBUTION A RAD ION INTENSI OF RADI TIVE MATERIALS DEPOSITE A SPACE Filed Sept. 10, 1963 2 Sheets-Sheet 2 United States Patent Germany, a corporation of Germany Filed Sept. 10, 1963, Ser. No. 308,030 Claims priority, application Germany, Sept. 21, 1962,

9 Claims. (a. ass-6s My invention relates to a method and apparatus for determining the radioactivity of materials and more particularly, for determining the local distribution and radiation intensity of radioactive materials deposited in a space.

Spaces in which radioactive materials are used or into which radioactive material can penetrate, for example walks and other spaces used by personnel to gain access in nuclear reactor installations for repair and maintenance thereof, must be continuously inspected for radioactive radiations. In such spaces, local contaminations are frequently produced primarily because of the deposit of radioactive materials at locations that are not satisfactorily ventilated or that are incompletely rinsed with fluids. Access to such spaces is consequently made difiicult and on many occasions is generally impossible. When the locations from which the radioactive radiation emanates are known, however, the radioactive materials deposited there can be removed or can be screened oif by constructing a protective wall. The usual dosage measurement with counter tubes, ionization chambers or films, provides no information as to where the radiation comes from (i.e. the location of the source of the radiation).

It is accordingly an object of my invention to provide a method and apparatus for determining the source location and the intensity of radiation of radioactive material located in a space.

With the above and other related objects in view, and in accordance with my invention, I provide a point by point recorded image of the radiation placed into registry with 8. represented image of the space as seen from the same viewing angle. A photograph is used advantageously for the image of the space and is taken from the same point from which the image of the radiation is recorded. The distribution of radioactive material can then be directly read therefrom. A camera with a displaceable objective is used for recording or radiographing the radiation image. The degree of photographic or radiographic density of the radiation image is adjustable to the intensity and the intended exposure time by means of a suitable choice of objective stops. An integrating record over a relatively long period is also possible.

The camera which is used for recording the radiation image in accordance with my invention comprises a chamher that is screened from radioactive radiation on all sides, for example with lead, is provided with a replaceable carrier coated with a radiation-sensitive film and is also provided with a sphere acting as objective which is formed with a bore hole running through its center and is rotatable about two axes that are perpendicular to one another. The sphere also consists of lead or any other good radiation screening material. One of the axes about which the sphere is rotatable coincides with the center axis of the bore hole. The other axis which is perpendicular thereto is defined by two trunnions that are arranged diametrically in a ring surrounding the sphere. The camera is thus in a position to photograph every point within an angle of 90 in this space.

Other features which are considered as characteristic for the invention are set forth in the appended claims.

The invention, both as to its construction and method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIG. 1 is a sectional view of the camera for photographing radiation constructed in accordance with my invention;

FIG. 2 is a front elevational View of FIG. 1 partly in section as viewed along the line lIl1 in FIG. 1 in the direction of the arrows;

FIG. 3 is a fragmentary sectional view of FIG. 2 taken along the line III-III in the direction of the arrows; and

FIG. 4 is a perspective view partly in section of a camera embodying my invention, having a drive mechanism which differs from the drive mechanism shown in FIG. 1.

Referring to the drawings and first particularly to FIGS. 1 and 2, there is shown a camera which includes a hollow body 10 consisting of material that screens radioactive radiation, such as lead for example, and provided with a hollow space 11 defined by a removable rear wall 12 and a sphere 13. The surface of the hollow body wall 10 adjacent to the sphere 13 conforms to the sphere with slight play therebetween. There is provided on the rear wall 12 a film holder for receiving a plate 14 or photographic film which is coated with an emulsion that becomes blackened by radioactive radiation. The rear wall 12 and the sphere 13 also consist of material, such as lead for example, which screens out radioactive radiation. The sphere is provided with a graduated bore hole passing through its center within which there is accommodated an interchangeable insert 15 formed with a longitudinally extending bore. The sphere is also provided with two diametrically arranged pivot bosses or trunnions 17 which are rotatably mounted in a gimbal ring 16 which concentrically surrounds the sphere. The inner surface of the ring 16 conforms to the sphere, and a toothed ring 13 in which a pinion 19 meshes is arranged on the outer surface of the gimbal ring 16. The ring 16 is mounted in the hielding body 10 with the aid of a slide bearing 20 and, with the aid of another slide bearing 21, in a retaining ring or balloon catch 22 which is screwed into the shielding body 10. The ring 16 carries another coaxial ring 23 which is also provided with a toothed ring 24. The toothed ring 24 whose diameter is, for example, larger than that of the toothed ring 18, is driven by a pinion 25 which is secured together with the pinion 19 on a common shaft 26. The toothed rings 16 and 24 consequently rotate at different speeds. Milled into the inner side of the ring 23 is a guiding groove 27 which is engaged by a projection 29 of a slide 28 (FIG. 3). At the other end of the slide 28 there is provided a pivot boss 30 which is inserted in a recess 31 provided in the sphere 13. Due to the difference in the motion of the [

rings

16 and 23, the slide 28 rotates the sphere 13 about the axis determined by the pivot bosses 17 so that the bore hole of the sphere is moved slowly through an angle with respect to the longitudinal axis of the camera (i.e. about an axis at 17 perpendicular to the plane of the paper as shown in FIG. 1) while the sphere simultaneously rotates about the longitudinal axis of the camera (i.e. about the dot-dash line shown in FIG. 1). Due to the suitable profiling of the corridor, the rays which penetrate through the bore hole of the sphere draw an image of the space in spiral lines on the radiation-sensitive emulsion of the plate or film 14, so that the entire picture area is simultaneously irradiated or illuminated. The extent to which the emulsion is blackened can be adjusted to the intensity and exposure period provided for by means of the insert 15. To this end, in accordance with the need, inserts with larger or smaller bore holes can be used, thereby producing the effect of a diaphragm. In order to prevent the penetration of radioactive particles into the interior of the camera, the front opening of the camera housing can be covered by a radiation-permeable metal sheet, for example of aluminum.

Another embodiment of a movable objective system is shown schematically in a perspective view in FIG. 4. The sphere 13 with an interchangeable objective insert 15 is mounted by diametrically arranged trunnions 34 in a ring 33, the inner surface of which conforms to the sphere surface and the outer casing of which is interrupted stepwise so that the penetration of radiation is prevented. The ring 33 is rotatably mounted in the shielding camera body or housing and is provided on one side, for example, with a toothed ring 37 in which a pinion 38 se cured to a driven shaft 39 meshes. One of the pivot trunnions 34 extends through the ring 33 and carries a pinion 35 which rotates through a groove 40 in the housing 10 as the ring 33 rotates. The pinion accordingly meshes with a toothed ring 36 mounted on one of the two side walls of the groove. The sphere 13 rotates therefore with this construction about two axes that are perpendicular to each other. Since the rotational velocity of the sphere about the axis determined by the trunnions 34 is quite large compared to the rotational velocity of the ring 33, the sketch of the radiation is drawn in parallel, inclined or slightly crooked lines on the radiationsensitive emulsion.

While the invention has been illustrated and described as embodied in an apparatus for determining the local distribution and radiation intensity of radioactive material deposited in a space and the method of eifecting the same, it is not intended to be limited to [the details shown, since various modification and structural changes may be made without departing from the spirit of the present invention and within the scope and range of equivalents of the following claims.

I claim:

1. An apparatus for determining the local distribution and radiation intensity of radioactive materials deposited in a space, comprising a chamber shielded on all sides against radioactive radiation, replaceable carrier means including an illustration of the space taken from a specific viewing angle, said illustration being coated with a radiationsensitive film and being mounted in a specific plane in said chamber, and a sphere partly defining said chamber and spaced from said radiation-sensitive film, said sphere being formed with a central bore communicating between said chamber and the exterior thereof and being rotatable about a pair of mutually perpendicular axes, one of said axes being located transverse to said specific plane and the other of said axes being located substantially parallel thereto, said one axis coinciding at a position of said sphere with the axis of said bore, said sphere being provided with a pair of opposed trunnions aligned on the other of said axes, and mechanism for rotating said sphere, said mechanism comprising first rotatable means surrounding said sphere and having an axis of rotation coinciding with said one axis, drive means for rotating said first rotatable means about said axis of rotation, said trunnions being diametrically mounted in said first rotatable means, and second rotatable means connected between said first rotatable means and said sphere for rotating said sphere about said other axis as said first rotatable means is rotated about said axis of rotation by said drive means, so that an area of the space wherein radioactive materials are deposited at the exterior of said chamber and a corresponding area of said radiation-sensitive film are simultaneously scannable at said specific viewing angle through said bore, whereby said sphere acts as a camera objective focussing radiation in the exterior area through said bore onto said radiation-sensitive film for forming a recorded image of the radiation superimposed on said illustration.

2. An apparatus according to claim 1 wherein the i1lus tration of said carrier means comprises a photograph of the space in which the radioactive materials are deposited taken along the same viewing angle as the viewing angle along which the recorded image of the radiation on the radiation-sensitive film is taken.

3. Apparatus according to claim 1, wherein said sphere includes a tubular insert interchangeably secured in a diametrical bore hole of said sphere, said central bore of said sphere extending longitudinally through said insert and being of selected diameter and shape.

4. An apparatus for determining the local distribution and radiation intensity of radioactive materials deposited in a space, comprising a chamber shielded on all sides against radioactive radiation, replaceable carrier means including an illustration of the space taken from a specific viewing angle, said illustration being coated with a rad-iation-sensitive film and being mounted in a specific plane in said chamber, and a sphere partly defining said chamber and spaced from said radiation'sensitive film, said sphere being formed with a central bore communicating between said chamber and the exterior thereof and being rotatable about a pair of mutually perpendicular axes, one of said axes being located transverse to and the other substantially parallel to said specific plane, said one axis coinciding at a position of said sphere with the axis of said bore, said sphere being provided with a pair of opposed trunnions aligned on the other of said axes, and mechanism for rotating said sphere, said mechanism comprising a ring surrounding said sphere and having an axis of rotation coinciding with said one axis, drive means for rotating said ring about said axis of rotation, said trunnions being diametrically mounted in said ring, and rotatable means connected between said ring and said sphere and adapted to rotate said sphere about said other axis as said ring is rotated about said axis of rotation by said drive means so that an area of the space wherein radioactive materials are deposited at the exterior of said chamber and a corresponding area of said radiation-sensitive film are simultaneously scannable at said specific viewing angle through said bore, whereby said sphere acts as a camera objective focussing radiation in the exterior area through said bore onto said radiation-sensitive film for forming a recorded image of the radiation superimposed on said illustration.

5. An apparatus for determining the local distribution and radiation intensity of radioactive materials deposited in a space, comprising a chamber shielded on all sides against radioactive radiation, replaceable carrier means including an illustration of the space taken from a specific viewing angle, said illustration being coated with a radia tion-sensitive film and being mounted in a specific plane in said chamber, and a sphere partly defining said chamber and spaced from said radiation-sensitive film, said sphere being formed with a central bore communicating between said chamber and the exterior thereof and being rotatable about a pair of mutually perpendicular axes, one of said axes being located transverse to and the other substantially parallel to said specific plane, said one axis coinciding at a position of said sphere with the axis of said bore, said sphere being also provided with a pair of opposed trunnions aligned on the other of said axes, and

mechanism for rotating said sphere, said mechanism comprising a first ring surrounding said sphere and having an axis of rotation coinciding with said one axis, drive means for rotating said first ring about said axis of rotation, said trunnions being diametrically mounted in said first ring, a second ring coaxially mounted on said first ring and rotatably driven by said drive means about said axis of rotation at a rotary speed different from that of said first ring, a slide member having a projection slidably engageable in a groove formed on the inner surface of said second ring and pivotably mounted on said sphere so as to rotate said sphere about said other axis as said rings are rotated about said axis of rotation by said driving means, so that an area of the space wherein radioactive materials are deposited at the exterior of said chamber and a corresponding area of said radiation sensitive film are simultaneously scannable at said specific viewing angle through opposite ends of said bore, whereby said sphere acts as a camera objective focussing radiation in the exterior area through said bore onto said radiation-sensitive film for forming a recorded image of the radiation superimposed on said illustration.

6. An apparatus according to claim 5 wherein one of said pair of rings is mounted circumferentially on the other of said rings and said rings are rotatable relative to each other about said one axis.

7. An apparatus for determining the local distribution and radiation intensity of radioactive materials deposited in a space, comprising a chamber shielded on all sides against radioactive radiation, replaceable carrier means including an illustration of the space taken from a specific viewing angle, said illustration being coated with a radiation sensitive film and being mounted in a specific plane in said chamber, a sphere partly defining said chamber and spaced from said radiation-sensitive film, said sphere being formed Wit-h a central bore communicating between said chamber and the exterior thereof and being rotatable about a pair of mutually perpendicular axes, one of said axes being located transverse to and the other substantially parallel to said specific plane, said one axis coinciding at a position of said sphere with the axis of said bore, said sphere being also provided with a pair of opposed trunnions aligned on the other of said axes, and mechanism for rotating said sphere, said mechanism comprising a pair of relatively rotatable coaxial rings surrounding said sphere and having an axis of rotation coinciding with said one axis, said trunnions being diametrically and pivotably mounted on one of said rings, said rings being of different diameter and provided with teeth along their periphery, drive means comprising a pair of coaxial pinions secured to a common shaft, said pinions meshing respectively with the teeth of said rings for rotating said rings, and a slide member having a projection slidably engageable in a groove formed on the inner surface of the other of said rings and pivotably mounted on said sphere so .as to rotate said sphere about said other axis as said rings are rotated about said axis of rotation by.

said pinions, so that an area of the space wherein radioactive m-aterials are deposited at the exterior of said chamber and a corresponding area of said radiation-sensitive film are simultaneously scannable at said specific viewing angle through opposite ends of said bore in a substantially spiral trace, whereby said sphere acts as a camera objective focussing radiation in the exterior area through said bore onto said radiation-sensitive film for forming a recorded image of the radiation superimposed on said illustration.

8. An apparatus for determining the local distribution and radiation intensity of radioactive materials deposited in a space, comprising a chamber shielded on all sides against radioactive radiation, replaceable carrier means including an illustration of the space taken from a specific viewing angle, said illustration being coated with a radiation-sensitive film and being mounted in a specific plane in said chamber, a sphere partly defining said chamber and spaced from said radiation-sensitive film, said sphere being formed with a central bore communicating between said chamber and the exterior thereof and being rotatable about a pair of mutually perpendicular axes, one of said axes being located transverse to and the other substantially parallel to said specific plane, said one axis coinciding at a position of said sphere with the axis of said bore, said sphere being also provided with a pair of opposed trunnions aligned on the other of said axes, and mechanism for rotating said sphere, said mechanism comprising a pair of relatively rotatable coaxial rings of different diameter surrounding said sphere and provided with teeth along their outer periphery, said rings having an axis of rotation coinciding with said one axis, said trunnions being diametrically and pivotably mounted on one of said rings, drive means comprising a pair of coaxial pinions of different diameter secured to a common shaft, said pinions of smaller and larger diameters meshing respectively with the teeth of said rings of larger and smaller diameters for rotating said rings at respectively greater and lesser speeds, and a slide member having a projection at one end thereof slidably engageable in an arcuate groove formed on the inner surface of the other of said rings and :having a pivot at the other end thereof received in a recess in said sphere so as to rotate said sphere about said other axis as said rings are rotated about said axis of rotation by said pinions, so that an area of the space wherein radioactive materials are deposited at the exterior of said chamber and a corresponding area of said radiation-sensitive film are simultaneously scannable at said specific viewing angle through opposite ends of said bore in a substantially spiral trace, whereby said sphere acts as a camera objective focussing radiation in the exterior area through said bore onto said radiation-sensitive film for forming a recorded image of the radiation superimposed on said illustration.

9. An apparatus for determining the local distribution and radiation intensity of radioactive materials deposited in a space, comprising a chamber shielded on all sides against radioactive radiation, replaceable carrier means including an illustration of the space taken from a specific viewing angle, said illustration being coated with a radiation-sensitive film and being mounted in a specific plane in said chamber, a sphere partly defining said chamber and spaced trom said radiation-sensitive film, said sphere being formed with a central bore communicating between said chamber and the exterior thereof and being rotatable about a pair of mutually perpendicular axes, one of said axes being located transverse to and the other substantially parallel to said specific plane, said one axis coinciding at a position of said sphere with the axis of said bore, said sphere being also provided with a pair of opposed trunnions aligned on the other of said axes, a ring surrounding said sphere and having an axis of rotation coinciding with said one axis, means for rotating said ring about said axis of rotation, said trunnions being diametrically mounted in said rotatable ring, one of said trunnions extending through said ring and carrying a pinion at the free end thereof, said chamber having a cylindrical wall surrounding and journalling said ring, said cylindrical wall being formed with an inner annular groove adjacent the periphery of said ring, said groove having a lateral annular surface provided with teeth, said pinion being received in said groove in meshing engagement with the teeth of said lateral annular surface thereof for rotating said sphere about said other axis as said ring is rotated about said axis of rotation by said rotating means so that an area of the space wherein radioactive materials are deposited at the exterior of said chamber and a corresponding area of said radiation-sensitive film are simultaneously scannable at said specific viewing angle through opposite ends of said bore, whereby said sphere acts as a camera objective focussing radiation in the exterior area through said bore onto said radiation-sensitive film for forming a recorded image of the radiation superimposed on said illustration.

References Cited by the Examiner UNITED STATES PATENTS 2,285,768 6/ 1942 Drucker 50 X 2,335,700 11/ 1943 Rogers 9550 X 2,396,069 3/ 1946 Zapp 2506S 2,400,516 5/1946 Kieffer 250-61.5 2,684,446 7/ 1954 Paatero 250-65 2,895,049 7/ 1959 Astheimer et :al. 250-65 RALPH G. NILSON, Primary Examiner.

W. F. LINDQUIST, Assistant Examiner.

Claims

1. AN APPARATUS FOR DETERMINING THE LOCAL DISTRIBUTION AND RADIATION INTENSITY OF RADIOACTIVE MATERIALS DEPOSITED IN A SPACE, COMPRISING A CHAMBER SHIELDED ON ALL SIDES AGAINST RADIOACTIVE RADIATION, REPLACEABLE CARRIER MEANS INCLUDING AN ILLUSTRATION OF THE SPACE TAKEN FROM A SPECIFIC VIEWING ANGLE, SAID ILLUSTRATION BEING COATED WITH A RADITION-SENSITIVE FILM AND BEING MOUNTED IN A SPECIFIC PLANE IN SAID CHAMBER, AND A SPHERE PARTLY DEFINING SAID CHAMBER AND SPACED FROM SAID RADIATION-SENSITIVE FILM, SAID SPHERE BEING FORMED WITH A CENTRAL BORE COMMUNICATING BETWEEN SAID CHAMBER AND THE EXTERIOR THEREOF AND BEING ROTATABLE ABOUT A PAIR OF MUTUALLY PERPENDICULAR AXES, ONE OF SAID AXES BEING LOCATED TRANSVERSE TO SAID SPECIFIC PLANE AND THE OTHER OF SAID AXES BEING LOCATED SUBSTANTIALLY PARALLEL THERETO, SAID ONE AXIS COINCIDING AT A POSITION OF SAID SPHERE WITH THE AXIS OF SAID BORE, SAID SPHERE BEING PROVIDED WITH A PAIR OF OPPOSED TRUNNIONS ALIGNED ON THE OTHER OF SAID AXES, AND MECHANISM FOR ROTATING SAID SPHERE, SAID MECHANISM COMPRISING FIRST ROTATABLE MEANS SURROUNDING SAID SPHERE AND HAVING AN AXIS OF ROTATION COINCIDING WITH SAID ONE AXIS, DRIVE MEANS FOR ROTATING SAID FIRST ROTATABLE MEANS ABOUT SAID AXIS OF ROTATION, SAID TRUNNIONS BEING DIAMETRICALLY MOUNTED IN SAID FIRST ROTATABLE MEANS, AND SECONE ROTATABLE MEANS CONNECTED BETWEEN SAID FIRST ROTATABLE MEANS AND SAID SPHERE FOR ROTATING SAID SPHERE ABOUT SAID OTHER AXIS AS SAID FIRST ROTATABLE MEANS IS ROTATED ABOUT SAID AXIS OF ROTATION BY SAID DRIVE MEANS, SO THAT AN AREA OF THE SPACE WHEREIN RADIOACTIVE MATERIALS ARE DEPOSITED AT THE EXTERIOR OF SAID CHAMBER AND A CORRESPONDING AREA OF SAID RADIATION-SENSITIVE FILM ARE SIMULTANEOUSLY SCANNABLE AT SAID SPECIFIC VIEWING ANGLE THROUGH SAID BORE, WHEREBY SAID SPHERE ACTS AS A CAMERA OBJECTIVE FOCUSSING RADIATION IN THE EXTERIOR AREA THROUGH SAID BORE ONTO SAID RADIATION-SENSITIVE FILM FOR FORMING A RECORDED IMAGE OF THE RADIATION SUPERIMPOSED ON SAID ILLUSTRATION.