Dosimetry apparatus, systems, and methods

• US 8,841,622 B2
• Filed: 08/13/2013
• Issued: 09/23/2014
• 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
• Primary Examiner(s): Porta, David
• Assistant Examiner(s): Igyarto, Carolyn
• Application Number:
  US13/966,201
• Publication Number:
  US 20130334432A1
• Time in Patent Office: 406 Days
• Field of Search: 250/370.01, 250/300, 250/370.07
• 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;

wherein the first layer has more than one MOSFET structure formed thereon, 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; and

wherein each ion chamber is filled with;

a different gas;

or

a gas having different pressure.

2. The dosimeter of claim 1 wherein each ion chamber has a different size.

3. 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.

4. The dosimeter of claim 3 wherein the communications interface is a wired interface.

5. The dosimeter of claim 4 wherein the communications interface is a USB port or connection.

6. The dosimeter of claim 3 wherein the communications interface is a wireless interface.

7. The dosimeter of claim 3 wherein the communications interface includes data integrity checking and encryption.

8. The dosimeter of claim 3 wherein the dosimeter is connected to the internet through the communications interface.

9. The dosimeter of claim 3 wherein the data conversion and communications interfaces are externally powered.

10. The dosimeter of claim 9 wherein the data conversion and communications interfaces are powered inductively or by RF interrogation, or by electrical connection to an external power source.

11. The dosimeter of claim 3 wherein the communications interface further comprises an alarm signal receiving circuit.

12. The dosimeter of claim 11 further comprising an indicator device connected to the alarm signal receiving circuit.

13. 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.

14. The DIS radiation dosimeter package of claim 13 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 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 the concavity in the third layer are aligned with the exposed surface of the floating gate to form an ion chamber, and the concavity in the second layer communicates with the concavity in the third layer through the first layer.

15. The DIS radiation dosimeter package of claim 14 wherein the data collection and data readout integrated circuit includes data integrity checking and encryption.

16. The DIS radiation dosimeter package of claim 14 wherein the data collection and data readout integrated circuit is externally powered.

17. The DIS radiation dosimeter package of claim 16 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.

18. The DIS radiation dosimeter package of claim 14 wherein the data collection and data readout integrated circuit further comprises an alarm signal receiving circuit.

19. The DIS radiation dosimeter package of claim 18 further comprising an indicator device connected to the alarm signal receiving circuit.