Graphite X-ray window
The x-ray windows herein can have low gas permeability, low outgassing, high strength, low visible and infrared light transmission, high x-ray flux, low atomic number materials, corrosion resistance, high reliability, and low-cost. The x-ray window can include a film 11 with a polymer layer 22 and a graphite layer 21 . The film 11 can consist essentially of graphite and polymer. Most of the film 11 can be the graphite layer 21 . The polymer layer 22 can be a small portion of the film 11.
1. An x-ray window comprising:
a film spanning an aperture of a frame;
the film across the aperture has ≥70 mass percent carbon;
3 μm≤T11≤100 μm, where T11 is a maximum thickness of the film across the aperture;
the film includes a polymer layer on a graphite layer; and
T21/T22>1, where T21 is a thickness of the graphite layer and T22 is a thickness of the polymer layer.
2. The x-ray window of claim 1 , wherein the polymer layer faces a vacuum and the graphite layer faces ambient pressure.
3. The x-ray window of claim 1 , wherein the polymer layer adjoins the graphite layer.
4. An x-ray device comprising:
an x-ray window mounted to a frame;
the x-ray window including a film spanning an aperture of a frame;
the film across the aperture has ≥70 mass percent carbon; and
3 μm≤T11≤100 μm, where T11 is a maximum thickness of the film across the aperture.
5. The x-ray device of claim 4 , wherein the aperture is void of solid material except for the film.
6. The x-ray device of claim 4 , wherein:
the film includes a polymer layer on a graphite layer; and
T21/T22>1, where T21 is a thickness of the graphite layer and T22 is a thickness of the polymer layer.
7. The x-ray device of claim 6 , wherein:
2 μm≤T21≤25 μm; and
20 nm≤T22≤500 nm.
8. An x-ray window comprising:
a film including a polymer layer on a graphite layer; and
T21/T22>1, where T21 is a thickness of the graphite layer and T22 is a thickness of the polymer layer.
9. The x-ray window of claim 8 , wherein the film has ≥70 mass percent carbon.
10. The x-ray window of claim 8 , wherein 3 μm≤T11≤100 μm, where T11 is a maximum thickness of the film.
11. The x-ray window of claim 8 , wherein the polymer layer includes polyimide.
12. The x-ray window of claim 8 , wherein the polymer layer faces a vacuum and the graphite layer faces ambient pressure.
13. The x-ray window of claim 8 , wherein the polymer layer adjoins the graphite layer.
14. The x-ray window of claim 8 , wherein the film has ≥80 mass percent carbon.
15. The x-ray window of claim 8 , wherein T21/T22≥10.
16. The x-ray window of claim 8 , wherein T21/T22≥50.
17. The x-ray window of claim 8 , wherein T21/T22≤500.
18. The x-ray window of claim 8 , wherein:
2 μm≤T21≤25 μm; and
20 nm≤T22≤500 nm.
19. The x-ray window of claim 8 , wherein the film consists essentially of graphite and polyimide.
20. The x-ray window of claim 8 , wherein the film is planar across its width.