Low intensity X-ray and gamma-ray imaging device

• US 4,142,101 A
• Filed: 07/20/1977
• Issued: 02/27/1979
• Est. Priority Date: 07/20/1977
• Status: Expired due to Term

• Current Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Original Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Inventors: Yin, Lo I
• Primary Examiner(s): Willis, Davis L.
• Application Number:
  US05/817,415
• Time in Patent Office: 587 Days
• Field of Search: 250/361 R, 250/363, 250/369, 250/483, 250/487, 250/213 VT, 250/330
• US Class Current: 250/363.01
• CPC Class Codes: A61B 6/4258 for detecting non x-ray radiation, e.g. gamma radiation A61B6/037 takes precedence
• CPC Class Codes: G01T 1/1645 using electron optical imaging means, e.g. image intensifier tubes, coordinate photomultiplier tubes, image converter
• CPC Class Codes: H01J 29/385 Photocathodes comprising a layer which modified the wave length of impinging radiation
• CPC Class Codes: H01J 31/507 using a large number of channels, e.g. microchannel plates

Abstract

A radiation to visible light converter is combined with a visible light intensifier. The converter is a phosphor or scintillator material which is modified to block ambient light. The intensifier includes fiber optics input and output face plates with a photocathode-microchannel plate amplifier-phosphor combination. Incoming radiation is converted to visible light by the converter which is piped into the intensifier by the input fiber optics face plate. The photocathode converts the visible light to electrons which are amplified by a microchannel plate amplifier. The electrons are converted back to light by a phosphor layer and piped out for viewing by the output fiber optics face plate. The converter-intensifier combination may be further combined with it'"'"'s own radiation source or used with an independent source.

Claims

1. Apparatus for converting radiation to visible light, comprising:

means for converting incoming invisible radiation to visible light;

means for visible light intensification, which means includes a microchannel plate amplifier; and

means for light coupling said means for converting incoming radiation and said means for visible light intensification.

2. The apparatus of claim 1 wherein said apparatus is mechanically coupled with a radiation source.

3. The apparatus of claim 2 wherein said radiation means is a radioactive souce.

4. The apparatus of claim 2 wherein said radiation means is a radiation generator.

5. The apparatus of claim 2 wherein said radiation source may be made to radiate upon said means for converting incoming radiation.

6. The apparatus of claim 1 wherein said incoming radiation are X-rays.

7. The apparatus of claim 1 wherein said incoming radiation are gamma-rays.

8. The apparatus of claim 1 wherein said incoming radiation are charged particles.

9. The apparatus of claim 1 wherein said incoming radiation are neutral particles.

10. The apparatus of claim 1 wherein said means for converting incoming radiation is mechanically coupled to said means for visible light intensification.

11. The apparatus of claim 1 wherein said means for converting incoming radiation is phosphor.

12. The apparatus of claim 11 wherein said phosphor is one with high efficiency of conversion of X-rays to visible light.

13. The apparatus of claim 11 wherein said phosphor is a rare earth phosphor.

14. The apparatus of claim 11 wherein said phosphor is terbruim activated 90% gadolinuim and 10% lanthanum oxysulfide.

15. The apparatus of claim 1 wherein said means for converting incoming radiation is a scintillator material.

16. The apparatus of claim 15 wherein said scintillator material has a high efficiency of conversion of gamma-rays to visible light.

17. The apparatus of claim 15 wherein said scintillator material is selected from the group consisting of sodium iodide and cesuim iodide.

18. The apparatus of claim 17 wherein said sodium iodide and cesium iodide is impurity activated.

19. The apparatus of claim 15 wherein said scintillator material is plastic.

20. The apparatus of claim 1 wherein said means for converting incoming radiation includes a visible light shield which is transparent to X-ray and gamma-ray radiation.

21. The apparatus of claim 1 wherein said means for visible light intensification is contained in an evacuated area and said means for converting incoming radition is contained outside said evacuated area.

22. The apparatus of claim 1 wherein said means for converting incoming radiation is light coupled to said means for visible light intensification through fiber optics means.

23. The apparatus of claim 22 wherein said means for converting incoming radiation includes a phosphor layer deposit on said fiber optics means.

24. The apparatus of claim 22 wherein said means for converting incoming radiation is mechanically connected to said means for visible light intensification in a mechanically interchangeable fashion.

25. The apparatus of claim 24 wherein said means for converting incoming radiation is a luminescent layer deposited on a fiber optics plate independent of said means for visible light intensification.

26. The apparatus of claim 1 wherein said microchannel plate amplifier is two amplifiers in a chevron configuration.

27. The apparatus of claim 1 wherein said microchannel plate amplifier has curved channels.

28. The apparatus of claim 1 wherein said microchannel plate amplifier has channels with conical inputs.

29. A method of radiation imaging consisting of:

positioning a radiation source before an object and positioning a device behind the object which converts invisible radiation to visible light and subsequently intensifies visible light by means of a light intensifier including a microchannel plate amplifier.

30. The method of claim 29 wherein said radiation source is of low intensity and said device exhibits a high gain.

31. The method of claim 29 wherein said radiation source is an X-ray source.

32. The method of claim 29 wherein said radiation source is a gamma-ray source.

33. The method of claim 29 wherein said radiation source is a charged particle source.

34. The method of claim 29 wherein said radiation source is a neutral particle source.

35. The method of claim 29 wherein said radiation source is radioactive.

36. The method of claim 29 wherein said radiation source is a radiation generator.

37. The method of claim 29 wherein said radiation source is mechanically coupled to said device.