DOSIMETRY APPARATUS , SYSTEMS, AND METHODS

• US 20110024640A1
• Filed: 04/06/2009
• Published: 02/03/2011
• Est. Priority Date: 04/07/2008
• Status: Active Grant

• Current Assignee: Mirion Technologies Incorporated (American Capital Limited)
• Original Assignee: Mirion Technologies Incorporated (American Capital Limited)
• Inventors: Kahilainen, Jukka, Logan, Thomas
• Granted Patent: US 9,134,430 B2
• Time in Patent Office: Days
• US Class Current: 250/370.07
• CPC Class Codes: G01T 1/02 Dosimeters G01T1/15 takes precedence
• CPC Class Codes: G01T 1/026 Semiconductor dose-rate meters
• CPC Class Codes: G01T 1/14 Electrostatic dosimeters construction of ionisation chambers H01J47/02 ; electrometers G01R5/28
• CPC Class Codes: G01T 1/185 with ionisation chamber arrangements
• CPC Class Codes: G01T 1/24 with semiconductor detectors
• CPC Class Codes: G01T 1/244 Auxiliary details, e.g. casings, cooling, damping or insulation against damage by, e.g. heat, pressure or the like
• CPC Class Codes: G01T 3/00 Measuring neutron radiation G01T5/00 takes precedence
• CPC Class Codes: G01T 3/08 with semiconductor detectors
• CPC Class Codes: G01T 7/00 Details of radiation-measuring instruments
• CPC Class Codes: H01J 47/002 Vessels or containers
• CPC Class Codes: H01J 47/005 Gas fillings H01J47/12 takes precedence; Maintaining the desired pressure within the tube
• CPC Class Codes: H01J 47/02 Ionisation chambers
• CPC Class Codes: H05K 5/0278 of USB type details relating to connectors H01R27/00

Abstract

A direct ion storage (DIS) radiation detector or dosimeter has a design that is easy and low cost to manufacture using semiconductor processing techniques. The detectors include internal communications interfaces so they are easy to read. Different interfaces, including wired, e.g. USB ports, and wireless interfaces, may be used, so that the dosimeters may be read over the internet. The detectors can thus be deployed or used in a variety of detection systems and screening methods, including periodic or single time screening of people, objects, or containers at a location by means of affixed dosimeters; screening of objects, containers or people at a series of locations by means of affixed dosimeters, and surveillance of an area by monitoring moving dosimeters affixed to people or vehicles.

Claims

1. A direct ion storage (DIS) radiation dosimeter, comprising:

a first layer having a MOSFET structure formed thereon by semiconductor processing techniques, the MOSFET structure having a floating gate with an exposed surface;

a second layer having a concavity therein;

a third layer, optionally having a concavity therein;

the first layer being sandwiched between the second and third layer, the three layers being bonded together to form a hermetic seal;

wherein the concavity in the second layer, and any concavity in the third layer, are aligned with the exposed surface of the floating gate to form an ion chamber.

2. The dosimeter of claim 1 wherein the first layer has more than one MOSFET structure formed thereon, and the second layer has a corresponding number of concavities, and the third layer optionally has a corresponding number of concavities, to form an ion chamber over each MOSFET structure.

3. The dosimeter of claim 2 wherein each ion chamber has a different size.

4. The dosimeter of claim 2 wherein each ion chamber is filled with a different gas.

5. The dosimeter of claim 2 wherein each ion chamber is filled with a gas at a different pressure.

50. The dosimeter of claim 1 wherein the third layer has a concavity and the concavity in the second layer communicates with the concavity in the third layer through the first layer.

51. The dosimeter of claim 1 further comprising:

a data conversion interface electrically connected to the MOSFET structure;

a communications interface connected to the output of the data conversion interface;

the data conversion and communications interfaces being integral to the dosimeter.

52. The dosimeter of claim 51 wherein the communications interface is a wired interface.

53. The dosimeter of claim 52 wherein the communications interface is a USB port or connection.

54. The dosimeter of claim 51 wherein the communications interface is a wireless interface.

55. The dosimeter of claim 51 wherein the communications interface includes data integrity checking and encryption

56. The dosimeter of claim 51 wherein the dosimeter is connected to the internet through the communications interface.

57. The dosimeter of claim 51 wherein the data conversion and communications interfaces are externally powered.

58. The dosimeter of claim 57 wherein the data conversion and communications interfaces are powered inductively or by RF interrogation, or by electrical connection to an external power source.

59. The dosimeter of claim 51 wherein the communications interface further comprises an alarm signal receiving circuit.

60. The dosimeter of claim 59 further comprising an indicator device connected to the alarm signal receiving circuit.

6. A direct ion storage (DIS) radiation dosimeter, comprising:

a MOSFET having a floating gate with an exposed surface;

a data conversion interface electrically connected to the MOSFET;

a communications interface connected to the output of the data conversion interface;

the data conversion and communications interfaces being integral to the dosimeter.

7. The dosimeter of claim 6 wherein the communications interface is a wired interface.

8. The dosimeter of claim 7 wherein the communications interface is a USB port or connection.

9. The dosimeter of claim 6 wherein the communications interface is a wireless interface.

10. The dosimeter of claim 6 wherein the communications interface includes data integrity checking and encryption.

11. The dosimeter of claim 6 wherein the dosimeter is connected to the internet through the communications interface.

12. The dosimeter of claim 6 wherein the data conversion and communications interfaces are externally powered.

13. The dosimeter of claim 12 wherein the data conversion and communications interfaces are powered inductively or by RF interrogation, or by electrical connection to an external power source.

14. The dosimeter of claim 6 wherein the communications interface further comprises an alarm signal receiving circuit.

15. The dosimeter of claim 14 further comprising an indicator device connected to the alarm signal receiving circuit.

16. A system for screening a plurality of persons, objects, or containers at a location for radiation exposure or for radioactive sources carried therein or thereon, comprising:

a plurality of dosimeters, a dosimeter being attached to each person, object, or container present at the location, each dosimeter having an integral communications interface;

a dosimeter reader at the location for reading each dosimeter through its communications interface on a one time or on a periodic basis.

17. The system of claim 16 wherein the communications interface in each dosimeter is a wired or a wireless communications interface.

18. The system of claim 17 wherein the interface is a USB interface.

19. The system of claim 16 wherein the dosimeters are DIS, TLD, OSL, RPL, RC, MOSFET or other passive dosimeters.

20. The system of claim 16 further comprising a central station to which the reader is connected by wired or wireless communication.

66. The system of claim 16 wherein the dosimeters are direct ion storage (DIS) radiation dosimeters, comprising:

a first layer having MOSFET structure formed thereon by semiconductor processing techniques, the MOSFET structure having a floating gate with an exposed surface;

a second layer having a concavity therein;

a third layer, optionally having a concavity therein;

the first layer being sandwiched between the second and third layer, the three layers being bonded together to form a hermetic seal;

where in the concavity in the second layer, and any concavity in the third layer, are aligned with exposed surface of the floating gate to form an ion chamber.

21. A system for screening a plurality of objects, containers or persons being transported from a first location to a second location for radioactive sources carried therein or thereon, comprising:

a plurality of dosimeters, a dosimeter being attached to each object, container, or person present at the first location, each dosimeter having an integral communications interface;

a first dosimeter reader at the first location for reading each dosimeter through its communications interface before the associated object, container, or person leaves the first location;

a second dosimeter reader at the second location for reading each dosimeter through its communications interface when the associated object, container, or person arrives at the second location.

22. The system of claim 21 wherein the communications interface in each dosimeter is a wired or a wireless communications interface.

23. The system of claim 22 wherein the interface is a USB interface.

24. The system of claim 21 wherein the dosimeters are DIS, TLD, OSL, RPL, RC, MOSFET or other passive dosimeters.

25. The system of claim 21 further comprising a central station to which the first and second readers are connected by wired or wireless communication.

67. The system of claim 21 wherein the dosimeters are direct ion storage (DIS) radiation dosimeters, comprising:

a first layer having a MOSFET structure formed thereon by semiconductor processing techniques, the MOSFET structure having a floating gate with an exposed surface;

a second layer having a concavity therein;

a third layer, optionally having a concavity therein;

the first layer being sandwiched between the second and third layer, the three layers being bonded together to form a hermetic seal;

wherein the concavity in the second layer, and any concavity in the third layer, are aligned with the exposed surface of the floating gate to form an ion chamber.

26. A system for surveillance of an area for radioactive sources located therein, comprising:

a plurality of dosimeters, each dosimeter being attached to a person or a vehicle that moves through the surveillance area, each dosimeter having an integral communications interface;

a reader in communication with the dosimeters.

27. The system of claim 26 wherein the communications interface in each dosimeter is a wired or a wireless communications interface.

28. The system of claim 27 wherein the interface is a USB interface.

29. The system of claim 26 wherein the dosimeters are DIS, TLD, OSL, RPL, RC, MOSFET or other passive dosimeters.

30. The system of claim 26 wherein each dosimeter further comprises a locator device.

68. The system of claim 26 wherein the dosimeters are direct ion storage (DIS) radiation dosimeters, comprising:

a first layer having a MOSFET structure formed thereon by semiconductor processing techniques, the MOSFET structure having a floating gate with an exposed surface;

a second layer having a concavity therein;

a third layer, optionally having a concavity therein;

the first layer being sandwiched between the second and third layer, the three layers being bonded together to form a hermetic seal;

wherein the concavity in the second layer, and any concavity in the third layer, are aligned with the exposed surface of the floating gate to form an ion chamber.

31. A method for screening a plurality of persons, objects, or containers at a location for radiation exposure or for radioactive sources carried therein or thereon, comprising:

attaching a dosimeter to each person, object, or container present at the location, each dosimeter having an integral communications interface;

reading each dosimeter at the location through its communications interface on a one time or a periodic basis.

32. The method of claim 31 wherein the communications interface in each dosimeter is a wired or a wireless communications interface.

33. The method of claim 32 wherein the interface is a USB interface.

34. The method of claim 31 wherein the dosimeters are DIS, TLD, OSL, RPL, RC, MOSFET or other passive dosimeters.

35. The method of claim 31 further comprising transmitting data read from each dosimeter at the location to a central station for processing, and receiving reports back from the central station.

36. The method of claim 35 wherein transmitting data to the central station and receiving reports back are performed over the internet.

69. The method of claim 31 wherein the dosimeters are direct ion storage (DIS) radiation dosimeters, comprising:

a first layer having a MOSFET structure formed thereon by semiconductor processing techniques, the MOSFET structure having a floating gate with an exposed surface;

a second layer having a concavity therein;

a third layer, optionally having a concavity therein;

the first layer being sandwiched between the second and third layer, the three layers being bonded together to form a hermetic seal;

wherein the concavity in the second layer, and any concavity in the third layer, are aligned with the exposed surface of the floating gate to form an ion chamber.

37. A method for screening a plurality of objects, containers or persons being transported from a first location to a second location for radioactive sources carried therein or thereon, comprising:

attaching a dosimeter to each object, container, or person present at the first location, each dosimeter having an integral communications interface;

reading each dosimeter through its communications interface before the associated object, container, or person leaves the first location;

reading each dosimeter through its communications interface when the associated object, container, or person arrives at the second location.

38. The method of claim 37 wherein the communications interface in each dosimeter is a wired or a wireless communications interface.

39. The method of claim 38 wherein the interface is a USB interface.

40. The method of claim 37 wherein the dosimeters are DIS, TLD, OSL, RPL, RC, MOSFET or other passive dosimeters.

41. The method of claim 37 further comprising transmitting data read from the dosimeters at the first and second locations to a central station.

70. The method of claim 37 wherein the dosimeters are direct ion storage (DIS) radiation dosimeters, comprising:

a first layer having a MOSFET structure formed thereon by semiconductor processing techniques, the MOSFET structure having a floating gate with an exposed surface;

a second layer having a concavity therein;

a third layer, optionally having a concavity therein;

the first layer being sandwiched between the second and third layer, the three layers being bonded together to form a hermetic seal;

wherein the concavity in the second layer, and any concavity in the third layer, are aligned with the exposed surface of the floating gate to form an ion chamber.

42. A method for surveillance of an area for radioactive sources located therein, comprising:

attaching a plurality of dosimeters to persons or vehicles that move through the surveillance area, each dosimeter having an integral communications interface;

monitoring the plurality of mobile dosimeters at a reader in communication with the dosimeters.

43. The method of claim 42 wherein the communications interface in each dosimeter is a wired or a wireless communications interface.

44. The method of claim 43 wherein the interface is a USB interface.

45. The method of claim 42 wherein the dosimeters are DIS, TLD, OSL, RPL, RC, MOSFET or other passive dosimeters.

46. The method of claim 42 wherein each dosimeter further comprises a locator device.

47. The method of claim 42 wherein the reader is located at a central station.

48. The method of claim 42 further comprising transmitting data from the reader to a central station.

71. The method of claim 42 wherein the dosimeters are direct ion storage (DIS) radiation dosimeters, comprising:

a first layer having a MOSFET structure formed thereon by semiconductor processing techniques, the MOSFET structure having a floating gate with an exposed surface;

a second layer having a concavity therein;

a third layer, optionally having a concavity therein;

the first layer being sandwiched between the second and third layer, the three layers being bonded together to form a hermetic seal;

wherein the concavity in the second layer, and any concavity in the third layer, are aligned with the exposed surface of the floating gate to form an ion chamber.

49. A direct ion storage (DIS) radiation dosimeter package, comprising:

a housing having an aperture in an end thereof;

a frame fitting inside and slidably mounted in the housing;

a DIS radiation sensor mounted on the frame;

a data collection and data readout integrated circuit electrically connected to the DIS radiation sensor and mounted on the frame;

the data collection and data readout integrated circuit having a USB connection at one end thereof proximal to the aperture;

a base element rotatably attached to housing so that as the base element is rotated, the frame slides toward the aperture and the USB connection extends outside the aperture.

72. The DIS radiation dosimeter package of claim 49 wherein the DIS radiation sensor comprises:

a first layer having a MOSFET structure formed thereon by semiconductor processing techniques, the MOSFET structure having a floating gate with an exposed surface;

a second layer having a concavity therein;

a third layer, optionally having a concavity therein;

the first layer being sandwiched between the second and third layer, the three layers being bonded together to form a hermetic seal;

wherein the concavity in the second layer, and any concavity in the third layer, are aligned with the exposed surface of the floating gate to form an ion chamber.

73. The DIS radiation dosimeter package of claim 49 wherein the data collection and data readout integrated circuit includes data integrity checking and encryption.

74. The DIS radiation dosimeter package of claim 49 wherein the data collection and data readout integrated circuit is externally powered.

75. The DIS radiation dosimeter package of claim 74 wherein the data collection and data readout integrated circuit is powered inductively or by RF interrogation, or by electrical connection to an external power source.

76. The DIS radiation dosimeter package of claim 49 wherein the data collection and data readout integrated circuit further comprises an alarm signal receiving circuit.

77. The DIS radiation dosimeter package of claim 76 further comprising an indicator device connected to the alarm signal receiving circuit.

78. The DIS radiation dosimeter package of claim 72 wherein the third layer has a concavity and the concavity in the second layer communicates with the concavity in the third layer through the first layer.

61. A method of making a direct ion storage (DIS) radiation dosimeter comprising:

forming a first layer having MOSFET structure thereon by semiconductor processing techniques, the MOSFET structure having a floating gate with an exposed surface;

forming a second layer having a concavity therein;

forming a third layer, optionally having a concavity therein;

sandwiching the first layer between the second and third layer;

bonding the three layers together to form hermetic seal;

wherein the concavity in the second layer and any concavity in the third layer, are aligned with the exposed surface of the floating gate to form an ion chamber.

62. The method of claim 61 wherein the first layer is formed of a silicon substrate.

63. The method of claim 61 further comprising forming conducting electrical lines on the first layer so that electrical connection can be made to MOSFET structure.

64. The method of claim 61 wherein the second and third layers are formed of metal or conducting polymer.

65. The method of claim 61 wherein the third layer has a concavity therein and the concavity in the second layer communicates with the concavity in the third layer through the first layer.