Radiation dosimeters

• US 5,083,031 A
• Filed: 04/24/1989
• Issued: 01/21/1992
• Est. Priority Date: 08/19/1986
• Status: Expired due to Fees

• Current Assignee: Harris Trust and Savings Bank
• Original Assignee: International Sensor Technology, Inc. (Fortive Corp.)
• Inventors: Hegland, Joel E., Tetzlaff, Wolfgang, Hoelsher, James W., Braunlich, Peter F.
• Primary Examiner(s): FIELDS, CAROLYN
• Application Number:
  US07/343,000
• Time in Patent Office: 1,002 Days
• Field of Search: 250/484.1 A, 250/484.1 C, 250/337, 250/482.1, 250/486.1, 250/475.1
• US Class Current: 250/484.3
• CPC Class Codes: G01T 1/02 Dosimeters G01T1/15 takes precedence
• CPC Class Codes: G01T 1/11 Thermo-luminescent dosimeters thermo-luminescent compositions C09K11/00

Abstract

Radiation dosimeters and dosimeter badges. The dosimeter badges include first and second parts which are connected to join using a securement to produce a sealed area in which at least one dosimeter is held and protected. The badge parts are separated to expose the dosimeters to a stimulating laser beam used to read dose exposure information therefrom. The badge is constructed to allow automated disassembly and reassembly in a uniquely fitting relationship. An electronic memory is included to provide calibration and identification information used during reading of the dosimeter. Dosimeter mounts which reduce thermal heating requirements are shown. Dosimeter constructions and production methods using thin substrates and phosphor binder-layers applied thereto are also taught.

Claims

1. A radiation dosimeter badge having at least a first part and a second part;

at least one of said parts including a dosimeter holder for holding at least one luminescent dosimeter;

said first and second parts being controllably detachable using a rotatable mechanical connection;

a tamper-resistance means to controllably resist unauthorized detachment of the first and second parts of the dosimeter badge;

said tamper-resistance means including a tamper ring which engages to resist movement of a rotatable locking ring which is movable to controllably restrain the second and first parts of the dosimeter badge.

2. A radiation dosimeter badge in accordance with claim 1 wherein the tamper ring is biased to engage with the rotatable locking ring.

3. A radiation dosimeter badge having at least:

a first part;

a second part;

at least one of said first and second parts including a dosimeter holder for holding at least one luminescent dosimeter;

at least one locking member which is movably mounted to the first part;

said locking member being a rotatable locking ring mounted for controllable movement between at least one restraining position and at least one releasing position to controllably secure together and release the first and second parts, respectively;

said locking member including locking projections which engage with portions of the second part to force the first and second parts into sealing engagement;

sealing means for sealing between mating portions of the first and second parts;

a tamper-resistance means;

said tamper-resistance means including a tamper ring which engages to resist movement of the locking member.

4. A radiation dosimeter badge in accordance with claim 3 wherein the badge includes measns for allowing engagement of the tamper ring with a release tool.

5. A dosimeter mounting for holding at least one luminescent dosimeter, comprising:

a first dosimeter retainer;

a second dosimeter retainer;

said first and second dosimeter retainers being formed to engage a luminescent dosimeter about limited portions of the outer periphery of the luminescent dosimeter;

at least one of said retainers being formed to space the luminescent dosimeter away from an adjacent portion of a luminescent dosimeter badge to reduce heat transfer between the dosimeter and the supporting dosimeter badge;

wherein the first dosimeter retainer is a layer of temperature-resistant synthetic polymer resin and the second dosimeter retainer includes a plurality of metallic restraint bands which hold and restrain the dosimeter of the first dosimeter retainer.

6. A dosimeter mounting for holding at least one luminescent dosimeter, comprising:

a first dosimeter retainer;

a second dosimeter retainer;

said first and second dosimeter retainers being formed to engage a luminescent dosimeter about limited portions of the outer periphery of the luminescent dosimeter;

at least one of said retainers being formed to space the luminescent dosimeter away from an adjacent portion of a luminescent dosimeter badge to reduce heat transfer between the dosimeter and the supporting dosimeter badge;

wherein said first retainer member includes prongs which extend to laterally restrain the dosimeter in opposing directions along a first line of lateral action, and said second retainer member includes a deformable array of restraint elements which extend across the dosimeter face to restrain outward motion and along opposing sides of the dosimeter to restrain lateral motion along a second line of lateral action which is approximately perpendicular to said first line of lateral action, when the first and second retainer members are installed upon the dosimeter.

7. A dosimeter mounting according to claim 6 and wherein at least one of said first or second retainer members includes assembly prongs for deformably engaging about a retainer member to secure the first and second retainer members together in an assembly with a luminescent dosimeter held therebetween.

8. A method for producing a laser readable radiation dosimeter capable of withstanding relatively high temperature gradients and short-term temperatures in the range of 300°

-400°

C., comprising ;

selecting at least one particulate luminescent phosphor composition containing at least some luminescent phosphor material;

selecting at least one synthetic polymer binder composition having an ability to withstand short-term heating in the range of 300°

-400°

C.;

mixing the selected phosphor composition and synthetic polymer binder composition to a form a phosphor-binder mixture which ranges in consistency from being fluid to plastically deformable;

selecting a suitable substrate having a thickness of approximately 1000 microns or less adjacent to luminescent phosphr layer locations;

positioning a mask having mask openings therethrough adjacent the substrate with the mask openings located at desired luminescent phosphor layer locations;

depositing the phosphor-binder mixture through the mask openings and onto the substrate to form phosphor-binder deposits thereon;

curing the substrate and deposited phospor-binder deposits to harden and secure the phosphor-binder deposits upon the substrate.

9. A method according to claim 8 wherein said curing is accomplished by heating.

10. A method according to claim 8 wherein said curing is accomplished by heating to temperatures of approximately 150°

C. or greater.

11. A method according to claim 8 wherein said selecting particulate luminescent phosphor composition includes selecting particles generally less than 100 microns in size.

12. A method according to claim 8 wherein said synthetic polymer binder is a fluid when mixed with the particulate luminescent phosphor composition.

13. A method according to claim 8 wherein ratios of luminescent phosphor material to synthetic polymer binder in the phosphor-binder mixture are approximately in the range of 10:

1 to 1;

3 on the basis of weight of mixed constituents.

14. A method according to claim 8 and further defined to include overlaying the phosphor-binder deposits with a synthetic polymer binder to seal and protect said deposits.

15. A method according to claim 8 and further defined by:

selecting a suitable liquid vechile; and

wherein said mixing further comprises mixing the selected liquid vehicle with the selected phosphor composition and synthetic polymer binder to form a phosphor-binder-vehicle mixture whixh is used in said depositing to form said phosphor-binder deposits.

16. A method according to claim 8 wherein said selecting at least one synthetic polymer binder composition is defined to include selecting binder composition which includes at least some suitable polyimide.

17. A method according to claim 8 wherein said selecting at least one synthetic polymer binder composition is defined to include selecting a binder composition which includes at least some suitable silicone.

18. A method for producing a laser readable radiation dosimeter, comprising:

selecting at least one particulate luminescent phosphor composition containing at least some luminescent phosphor material;

selecting at least one fluid binder composition;

mixing the selected phosphor composition and binder composition to form a phosphor-binder mixture which ranges in consistency from being fluid to plastically deformable;

selecting a suitable substrate having a thickness of approximately 1000 microns or less adjacent to luminescent phosphor layer locations;

positioning a mask having mask openings therethrough adjacent the substrate with the mask openings located at desired luminescent phosphor layer locations;

depositing the phosphor-binder mixture through the mask openings and onto the substrate to form phospor-binder deposits thereon;

curing the deposited phosphor-binder deposits to harden and secure the phosphor-binder deposits upon the substrate.

19. A method for producing a laser readable radiation dosimeter, comprising:

selecting at least one particulate luminescent phosphor composition containing at least some luminescent phosphor material;

selecting at least one binder composition;

selecting at least one fluid vehicle composition;

mixing the selected phosphor composition, binder composition, and vehicle composition to form a phosphor-binder-vehicle mixture which ranges in consistency fromm being fluid to plastically deformable;

selecting a suitable substrate having a thickness of approximately 1000 microns or less adjacent to luminescent phospher layer locations;

positioning a mask having mask openings therethrough adjacent the substrate with the mask opening located at desired luminescent phosphor layer locations;

despositing the phosphor-binder-vehicle mixture through the mask openings and onto the substrate to form phosphor-binder deposits thereon;

curing the deposited phosphor-binder desposits to harden and secure the phosphor-binder deposits upon the substrate.

20. A method for producing a laser readable radiation dosimeter, comprising:

selecting at least one particulate luminescent phoshor composition contaning at least some luminescent phosphor material;

selecting at least one binder composition;

selecting at least one fluid vehicle composition;

mixing the selected binder composition and vehicle composition to form a binder-vehicle mixture which ranges in consistency from being fluid to plastically deformable;

selecting a suitable substrate having a thickness of approximately 1000 microns or less adjacent to luminescent phosphor layer locations;

positioning a mask having mask openings therethrough adjacent the substrate with the mask openings located at desired luminescent phosphor layer locations;

despositing the binder-vehicle mixture through the mask openings and onto the substrate to form binder-vehicle desposits thereon;

despositing selected particulate luminescent phosphor composition onto desposited binder-vehicle deposits to form phospher-binder-vehicle deposits;

curing the deposited phosphor-binder-vehicle deposits to harden and secure phosphor-binder deposits upon the substrate.

21. A method according to claim 20 wherein said curing is accomplished by heating.

22. A method according to claim 20 wherein said curing is accomplished by heating to temperatures of approximately 150°

C. or greater.

23. A method according to claim 20 wherein said selecting particulate luminescent phosphor composition includes selecting particles generally less than 100 microns in size.

24. A method according to claim 20 wherein ratios of luminescent phosphor material to synthetic polymer binder in the phosphor-binder mixture are approximately in the range of 10:

1 to 1;

3 on the basis of weight of mixed constituents.

25. A process for opening a tamper-resistant dosimeter badge, comprising:

inserting at least one tool into tamper element apertures formed in the dosimeter badge;

despressing at least one tamper-resistent element using said tool to remove the tamper-resistant element from a locking ring of the dosimeter badge;

rotating said locking ring to release at least one portion of the dosimeter badge and allow removed thereof.

26. A radiation dosimeter badge comprising:

a first part having an outer perimeter which is asymmetically shaped to uniquely identify the orientation of the first part;

a second part asymmetrically shaped to engage with the first part in a unique orientation with respect to the first part;

a plurality of dosimeter elements mounted to the second part in a desired arrangement;

said first and second parts being connectible together and detachable to allow separation of the second part from the first part for reading in a dosimeter handling machine;

at least one locking element movably mounted to said first part and movable between a locking position wherein at least one locking element engages the second part and retains it to the first part, and a releasing position wherein the second part is free for detachment from the first part.

27. A dosimeter according to claim 26 wherein the second part is received within a receptacle formed in the first part.

28. A dosimeter according to claim 26 wherein the second part is a disk shaped piece received within a receptacle formed in the first part;

and said locking element is an arcuate member mounted for arcuate slidable movement relative to said fist part.

29. A dosimeter according to claim 26 wherein the second part is a disk shaped piece received within a receptacle formed in the first part;

and said locking element is a ring member mounted for arcuate slidable movement relative to said first part.

30. A dosimeter according to claim 26 wherein the second part is a piece having a plurality sized perimeter segments received within a receptacle formed in the first part with corresponding sections which receive the perimeter segments.

31. A dosimeter according to claim 26 wherein the second part is a piece having a plurality of differing projections received within a receptacle formed in the first part;

said differing projections being engaged by the locking element at a plurality of locations about the second part to secure the second to the first part.

32. A dosimeter according to claim 26 and further comprising at least one tamper-resistant member which engages and restrains the locking member when the locking member is in the locking position.

33. A dosimeter according to claim 26 wherein the second part is a disk shaped piece received within a receptacle formed in the first part;

and said locking element is an arcuate member mounted for arcuate slidable movement relative to said first part; and

further comprising a tamper-resistant member which engages and restrains the locking member when the locking member is in the locking position.

34. A dosimeter badge comprising:

a first part;

a second part;

at least one dosimeter holder mounted to at least one of said first or second parts for holding at least one dosimeter;

a seal for sealing between the first and second parts to form a sealed dosimeter enclosure;

at least one locking member which is slidably mounted to the first part and movable between at least one locking position and at least one releasing position;

said locking member engaging the second part at a plurality of positions in the one locking position to controllably secure the first and second parts together in a sealed relationship;

said locking member releasing the second part in the at least one releasing position to allow separation of the second part from the first part;

wherein the locking member is mounted for arcuate slidable movement relative to the first part.

35. A dosimeter being according to claim 34 wherein the locking member is a ring member mounted for arcuate slidable movement relative to the first part.

36. A dosimeter badge according to claim 34 and further comprising at least one tamper-resistant member which engages and restrains the locking member when the locking member is in the at least one locking position.

37. A dosimeter badge according to claim 34 wherein the locking member is a ring member mounted for arcuate slidable movement relative to the first part;

and further comprising at least one tamper-resistant member which engages and restrains the locking member when the locking member is in the at least one locking position.

38. A luminescent dosimeter capable of withstanding relatively high temperature gradients and short-term temperatures in the range of 300°

-400°

C., made according to the process comprising;

selecting at least one particulate luminescent phosphor composition containing at least some luminescent phosphor material;

selecting at least one synthetic polymer binder composition having an ability to withstand short-term heating in the range of 300°

-400°

C.;

mixing the selected phosphor composition and synthetic polymer binder composition to form a phosphor-binder mixture ranges in consistency from being fluid to plastically deformable;

approximately

selecting a suitable substrate having a thickness of 1000 microns or less adjacent to luminescent phosphor layer locations;

positioning a mask having mask openings therethrough adjacent the substrate with the mask openings located at desired luminescent phosphor layer locations;

depositing the phosphor-binder mixture through the mask openings and onto the substrate to form phosphor-binder desposits thereon;

curing the substrate and deposited phosphor-binder deposits to harden and secure the phosphor-binder deposits upon the substrate.

39. A luminescent dosimeter according to claim 38 wherein said curing is accomplished by heating.

40. A luminescent dosimeter according to claim 38 wherein said curing is accomplished by heating to temperatures of approximately 150°

C. or greater.

41. A luminescent dosimeter according to claim 38 wherein said selecting at least one particulate luminescent phosphor composition includes selecting particles generally less than 100 microns in size.

42. A luminescent dosimeter according to claim 38 wherein said at least one synthetic polymer binder composition is a fluid when mixed with the particulate luminescent phosphor composition.

43. A luminescent dosimeter according to claim 38 wherein ratios of luminescent phosphor material to synthetic polymer binder the phosphor-binder mixture are approximately in the range of 10:

1 to 1;

3 on the basis of weight of mixed constituents.

44. A luminescent dosimeter according to claim 38 and further defined to include overlaying the phosphor-binder deposits with a synthetic polymer binder to seal and protect said deposits.

45. A luminescent dosimeter according to claim 38 and further defined by:

selecting a suitable liquid vehicle; and

wherein said mixing further comprises mixing the selected liquid vehicle with the selected phosphor composition and synthetic polymer binder to form a phosphor-binder-vehicle mixture which is used in said depositing to form said phosphor-binder deposits.

46. A luminescent dosimeter according to claim 38 wherein said selecting at least one synthetic polymer binder composition is defined to include selecting a binder composition which includes at least some suitable polyimide.

47. A luminescent dosimeter according to claim 38 wherein said selecting at least one synthetic polymer binder composition is defined to include selecting a binder composition which includes at least some suitable silicone.

48. A luminescent dosimeter according to the process comprising:

selecting at least one particulate luminescent phosphor composition containing at least some luminescent phosphor material;

selecting at least one fluid binder composition;

mixing the selected phosphor composition and binder composition to form a phosphor-binder mixture which ranges in consistency from being fluid to plastically deformable;

selecting a suitable substrate having a thickness of approximately 1000 microns or less adjacent to luminescent phosphor locations;

positioning a mask having mask openings therethrough adjacent the substrate with the mask openings located at desired luminescent phosphor layer locations;

depositing the phosphor-binder mixture through the mask openings and onto the substrate to form phosphor-binder deposits thereon;

curing the desposited phosphor-binder desposits to harden and secure the phosphor-binder deposits upon the substrate.

49. A luminescent dosimeter made according to the process comprising:

selecting at least one particulate luminescent phosphor composition containing at least some luminescent phosphor material;

selecting at least one binder composition;

selecting at least one fluid vehicle composition;

mixing the selected phosphor composition, binder composition, and vehicle composition to form a phosphor-binder-vehicle mixture which ranges in consistency from being fluid to plastically deformable;

selecting a suitable substrate having a thickness of approximately 1000 microns or less adjacent to luminescent phosphor layer locations;

positioning a mask having mask openings therethrough adjacent the substrate with the mask openings located at desired luminescent phosphor layer locations;

despositing the phosphor-binder-vehicle mixture through the mask openings and onto the substrate to form phosphor-binder desposits thereon;

curing the deposited phosphor-binder desposits to harden and secure the phosphor-binder desposits upon the substrate.

50. A luminescent dosimeter made according to the process comprising:

selecting at least one particulate luminescent phosphor composition containing at least some luminescent phosphor material;

selecting at least one binder comprising;

selecting at least one fluid vehicle composition;

mixing the selected binder composition and vehicle composition to form a binder-vehicle mixture which ranges in consistency from being fluid to plastically deformable;

selecting a suitable substrate having a thickness of approximately 1000 microns or less adjacent to luminescent phosphor layer locations;

positioning a mask having mask openings therethrough adjacent the substrate with the mask openings located at desired luminescent phosphor layer locations;

despositing the binder-vehicle mixture through the mask openings and onto the substrate to form binder-vehicle desposits thereon;

despositing selected particulate luminescent phosphor composition onto deposited binder-vehicle deposits to form phosphor-binder-vehicle deposits;

curing the deposited phosphor-binder-vehicle deposits to harden and secure phosphor-binder deposits upon the substrate.

51. A luminescent dosimeter according to claim 50 wherein said curing is accomplished by heating.

52. A luminescent dosimeter according to claim 50 wherein said curing is accomplished by heating to temperatures of approximately 150°

C. or greater.

53. A luminescent dosimeter according to claim 50 wherein said selecting at least one phosphor luminescent phosphor composition includes selecting particles generally less than 100 microns in size.

54. A luminescent dosimeter according to claim 50 wherein ratios of luminescent phosphor material to synthetic polymer binder in the phosphor-binder mixture are approximately in the range of 10:

1 to 1;

3 on the basis of weight of mixed constituents.