Image intensifier having an ion barrier with conductive material and method for making the same
View Patent ↗An image intensifier tube includes a collimator having multiple channels for receiving electrons from a photocathode layer, and a microchannel plate (MCP) having multiple channels for receiving electrons from the collimator. An ion barrier film (IBF) is disposed on top of an input side of the MCP, in which the IBF includes a small amount of conductive material. The IBF may include alumina doped with chromium oxide, or manganese oxide, or any other conductive material. The small amount of conductive material includes 1% to 5% of conductive material in a layer of non-conductive material.
1. An image intensifier tube comprising:
a collimator including multiple channels for receiving electrons from a photocathode layer;
a microchannel plate (MCP) having multiple channels for receiving electrons from the collimator; and
an ion barrier film (IBF) disposed on top of and in contact with the MCP between the collimator and the MCP, wherein the IBF comprises non-conductive material and approximately 1% to 5% of a conductive material.
2. The image intensifier tube of claim 1 , wherein the IBF comprises non-conductive alumina doped with the conductive material, and the conductive material comprises chromium oxide (Cr 2 O 3 ).
3. The image intensifier tube of claim 1 , wherein the IBF comprises alumina doped with the conductive material, and the conductive material comprises manganese oxide (Mn 3 O 4 ).
4. The image intensifier tube of claim 1 wherein the IBF comprises non-conductive alumina doped with the conductive material.
5. The image intensifier tube of claim 1 , wherein the IBF comprises approximately 2% of the conductive material in a layer of alumina.
6. The image intensifier tube of claim 1 wherein:
the IBF is disposed on top of the MCP, and
the IBF comprises approximately 98% of the non-conductive material and approximately 2% of the conductive material.
7. The image intensifier tube of claim 1 wherein:
the IBF is disposed on top of the MCP, and
the IBF comprises a layer of the conductive material deposited on top of a layer of the non-conductive material.
8. The image intensifier tube of claim 7 , wherein the layer of conductive material comprises metallic aluminum.
9. An imager comprising:
a microchannel plate (MCP) including multiple channels for receiving electrons from a photocathode layer, and
an ion barrier film (IBF) disposed on top of and in contact with the MCP between the MCP and the photocathode layer, wherein the IBF comprises a non-conductive material and 1% to 5% of conductive material.
10. The imager of claim 9 wherein the IBF comprises non-conductive alumina doped with the conductive material, and the conductive material comprises chromium oxide (Cr 2 O 3 ).
11. The imager of claim 9 wherein the IBF comprises non-conductive alumina doped with the conductive material, and the conductive material comprises manganese oxide (Mn 3 O 4 ).
12. The imager of claim 9 wherein the IBF comprises non-conductive alumina doped with the conductive material.
13. The imager of claim 9 wherein the IBF comprises approximately 2% of the conductive material in a layer of the non-conductive material, and the non-conductive material is alumina.
14. The imager of claim 9 wherein the IBF comprises approximately 98% of the non-conductive material and approximately 2% of the conductive material.
15. The imager of claim 9 wherein the IBF comprises a layer of the conductive material deposited on top of the non-conductive material.
16. The imager of claim 15 wherein the layer of conductive material is 5 to 10 Angstroms in thickness.
17. The imager of claim 9 , wherein the MCP comprises multiple, non-perpendicular channels and further comprising a collimator between the IBF and the photocathode.
18. The imager of claim 9 , wherein the layer of conductive material comprises metallic aluminum.
19. A method of making a microchannel plate (MCP) for an image intensifier tube, the method comprising the steps of:
forming an ion barrier film (IBF) on top of and in connect with an input side of the MCP, wherein the IBF comprises 1% to 5% of a conductive material; and
positioning the IBF between the MCP and a collimator.
20. The method of claim 19 wherein the step of forming includes:
forming the IBF with non-conductive alumina, and
doping the IBF with the conductive material, wherein the conductive material comprises chromium oxide (Cr 2 O 3 ).
21. The method of claim 19 wherein the step of forming includes forming the IBF with non-conductive alumina, and
doping the IBF with the conductive material, wherein the conductive material comprises manganese oxide (Mn 3 O 4 .
22. The method of claim 19 wherein the step of forming includes:
forming the IBF with non-conductive material, and
doping the IBF with approximately 2% of the conductive material.
23. The method of claim 19 wherein the step of forming includes:
forming the IBF with non-conductive material, and
depositing the conductive material in a layer 5 to 10 Angstroms in thickness on top of the non-conductive material.
24. The method of claim 23 , wherein the layer of conductive material comprises metallic aluminum.
25. The method of claim 19 , wherein the MCP comprises a plurality of glass fibers, each fiber comprising cladding glass, further comprising the steps of:
etching the glass fibers to form multiple channels of the MCP in which the multiple channels have walls formed by the cladding glass; and
positioning the IBF between the multiple channels of the MCP and the collimator.