Decontamination and sterilization system using large area x-ray source

• US 20060049359A1
• Filed: 09/30/2005
• Published: 03/09/2006
• Est. Priority Date: 04/01/2003
• Status: Active Grant

• Current Assignee: Cabot Microelectronics Corporation (Entegris Incorporated)
• Original Assignee: Cabot Microelectronics Corporation (Entegris Incorporated)
• Inventors: Busta, Heinz H., Lesiak, Stanley D.
• Granted Patent: US 7,447,298 B2
• Time in Patent Office: Days
• US Class Current: 250/370.90
• CPC Class Codes: A23L 3/263 with corpuscular or ionising radiation, i.e. X, alpha, beta or omega radiation laser plasma radiation A23L3/26
• CPC Class Codes: A61L 2/08 Radiation
• CPC Class Codes: A61L 2/082 X-rays
• CPC Class Codes: C02F 1/30 by irradiation
• CPC Class Codes: C08F 2/54 by X-rays or electrons
• CPC Class Codes: C08K 3/04 Carbon
• CPC Class Codes: H01J 2235/068 Multi-cathode assembly
• CPC Class Codes: H01J 2235/163 shaped for a particular application
• CPC Class Codes: H01J 35/04 Electrodes ; Mutual position thereof; Constructional adaptations therefor
• CPC Class Codes: H01J 35/065 Field emission, photo emission or secondary emission cathodes
• CPC Class Codes: H01J 35/116 Transmissive anodes acting as a window H01J35/186
• CPC Class Codes: H01J 35/16 Vessels; Containers; Shields associated therewith

Abstract

A novel x-ray treatment system utilizes one or more large area flat panel sources of x-ray radiation directed into a target zone. A target substance within the target zone is irradiated with x-ray radiation from the one or more flat panel sources, reducing the biological effects of a contaminant presence therein. The flat panel source comprises an electron source, an electron accelerator, and an electron target medium. The electron source may emit electrons either via field emission or thermionic emission. The x-ray source may operate in transmissive, reflective, or combined transmissive/reflective mode. The use of large area flat panel x-ray sources in the inventive systems allows for decreased installation and operational costs as well as increased efficiency.

Claims

1. A method of irradiating a target substance to reduce biological effects of a contaminant presence in the target substance, the method comprising:

providing at least one flat panel source of x-ray radiation having a width and height dimension;

placing the target substance within a target zone having a width and height dimension aligned with and substantially the same as or less than the width and height dimensions of the at least one flat panel x-ray source; and

irradiating the target substance with radiation from the at least one flat panel source to reduce the biological effects of the contaminant presence in the target substance.

2. The method according to claim 1, wherein the target substance comprises an edible substance.

3. The method according to claim 1, wherein the contaminant is bacterial, fungal or viral, and wherein reduction of the biological effects of the contaminant presence comprises killing an amount of the contaminant sufficient to substantially reduce a risk of infection in a consumer of the target substance.

4. The method according to claim 1, wherein the contaminant is bacterial, fungal or viral, and wherein reduction of the biological effects of the contaminant presence comprises killing an amount of the contaminant sufficient to substantially reduce spoilage of the target substance.

5. The method according to claim 1, wherein the contaminant is chemical, and wherein reduction of the biological effects of the contaminant presence comprises chemically modifying an amount of the contaminant sufficient to substantially reduce a risk of a toxic reaction in a consumer of the target substance.

6. The method according to claim 1, wherein irradiating the target substance to reduce biological effects of the contaminant presence in the target substance comprises irradiating the target substance for a predetermined time period at a predetermined dose level.

7. The method according to claim 1, wherein the one or more flat panel sources of x-ray radiation comprises a gated field emitter electron source and operates in a mode selected from the group consisting of reflective alone, transmissive alone and combined reflective/transmissive.

8. The method according to claim 1, wherein the one or more flat panel sources of x-ray radiation comprises a thermionic emitter electron source and operates in a mode selected from the group consisting of reflective alone, transmissive alone and combined reflective/transmissive.

9. The method according to claim 1, wherein the at least one flat panel source of x-ray radiation comprising multiple flat panel sources of x-ray radiation arranged to irradiate the target zone, and wherein the step of irradiating the target substance with radiation from the flat panel source further comprises irradiating the target substance with radiation from each of the multiple flat panel sources of x-ray radiation.

10. The method according to claim 1, wherein the at least one flat panel source of x-ray radiation comprises an electron source for providing electrons and a target, wherein the electrons provided by the electron source are accelerated toward and impact the target, thereby causing a release of x-ray radiation from the target.

11. The method according to claim 10, wherein the target is positively biased with respect to the electron source.

12. The method according to claim 10, wherein the target is grounded, and the electron source is negatively biased with respect to the target.

13. A treatment system for irradiating a target substance to reduce biological effects of a contaminant presence in the target substance, the treatment system comprising:

one or more flat panel sources of x-ray radiation, each having a width and height dimension; and

a target zone having a width and height dimension aligned with and substantially the same as or less than the width and height dimensions of each of the one or more flat panel x-ray sources, whereby irradiation of the target substance with radiation from the one or more flat panel sources serves to reduce the biological effects of the contaminant presence in the target substance.

14. The system according to claim 13, wherein the target substance comprises an edible substance.

15. The system according to claim 13, wherein the contaminant is bacterial, fungal or viral, and wherein reduction of the biological effects of the contaminant presence comprises killing an amount of the contaminant sufficient to substantially reduce a risk of infection in a consumer of the target substance.

16. The system according to claim 13, wherein the contaminant is bacterial, fungal or viral, and wherein reduction of the biological effects of the contaminant presence comprises killing an amount of the contaminant sufficient to substantially reduce spoilage of the target substance.

17. The system according to claim 13, wherein the contaminant is chemical, and wherein reduction of the biological effects of the contaminant presence comprises chemically modifying an amount of the contaminant sufficient to substantially reduce a risk of a toxic reaction in a consumer of the target substance.

18. The system according to claim 13, wherein the one or more flat panel sources of x-ray radiation are controlled to radiate the target substance for a predetermined time period at a predetermined dose level.

19. The system according to claim 13, wherein at least one of the one or more flat panel sources of x-ray radiation comprises a gated field emitter electron source and operates in a mode selected from the group consisting of reflective alone, transmissive alone and combined reflective/transmissive.

20. The system according to claim 13, wherein at least one of the one or more flat panel sources of x-ray radiation comprises a thermionic emission electron source and operates in a mode selected from the group consisting of reflective alone, transmissive alone and combined reflective/transmissive.

21. The system according to claim 13, wherein the one or more flat panel sources of x-ray radiation comprise multiple flat panel sources of x-ray radiation sources arranged such that each irradiates the target zone.

22. The system according to claim 13, wherein the target substance is liquid or gas, the system further comprising a conduit passing through the target zone for conveying the target substance through the target zone, wherein the conduit is substantially transparent to x-ray radiation in at least a portion of the conduit situated within the target zone.

23. A method of irradiating a target substance to polymerize the target substance, the method comprising:

providing at least one flat panel source of x-ray radiation having a width and height dimension;

transporting the target substance through a target zone having a width and height dimension aligned with and substantially the same as or less than the width and height dimensions of the at least one flat panel x-ray source; and

irradiating the target substance with radiation from the at least one flat panel source to polymerize the target substance.