1. An imaging system, comprising:
an electromagnetic interference (EMI) shield configured to shield one or more imaging components from electromagnetic interference, wherein the EMI shield comprises a first material having a first plurality of conductive elements integrally formed within a first nonconductive material, wherein the first material has a first generally nonconductive exterior.
2. The imaging system of claim 1, wherein the EMI shield surrounds an image detector panel.
3. The imaging system of claim 1, wherein the EMI shield at least substantially defines a panel-shaped portable housing.
4. The imaging system of claim 1, comprising an imaging component shielded by the EMI shield.
5. The imaging system of claim 4, wherein the imaging component comprises an x-ray component.
6. The imaging system of claim 1, wherein first plurality of conductive elements comprise fibers, particles, or a combination thereof.
7. The imaging system of claim 1, wherein the first material comprises a composite material, a compounded plastic, or a combination thereof.
8. The imaging system of claim 1, wherein the first plurality of conductive elements comprises stainless steel fibers and the first nonconductive material comprises polycarbonate.
9. The imaging system of claim 1, wherein the first plurality of conductive elements comprises carbon particles, or fibers, or a combination thereof, and the first nonconductive material comprises polycarbonate.
10. The imaging system of claim 1, wherein the EMI shield comprises a first component made of the first material and a second component made of a second material different from the first material, wherein the second material comprises a second plurality of conductive elements integrally formed within a second nonconductive material, and the second material has a second generally nonconductive exterior.
11. The imaging system of claim 10, wherein the first and second plurality of conductive materials are conductively coupled together through the first and second generally nonconductive exteriors, respectively.
12. The imaging system of claim 1, comprising a secondary shielding layer.
13. The imaging system of claim 12, wherein the secondary shielding layer comprises a conductive paint, a metallic foil, a woven fabric, or a combination thereof.
14. A method for shielding electromagnetic interference in an imaging system, comprising:
providing an electromagnetic interference (EMI) shielding enclosure comprising a first material consisting essentially of a first plurality of conductive elements disposed in a first non-conductive material and a second material consisting essentially of a second plurality of conductive elements disposed in a second non-conductive material, wherein the first plurality of conductive elements engages the second plurality of conductive elements to form a conduction path.
15. The method of claim 14, comprising conductively coupling the first material with the second material by extending a conductive interface structure into the first material, into the second material, or a combination thereof.
16. The method of claim 15, wherein extending the conductive interface structure comprises inserting or overmolding a metal stud in the first material, or the second material, or a combination thereof.
17. The method of claim 14, comprising conductively coupling the first material with the second material by abrading a non-conductive surface of the first material, or the second material, or both, to reveal a conductive surface having at least some of the conductive elements exposed.
18. The method of claim 14, wherein the first material, or the second material, or both comprise a compounded plastic.
19. The method of claim 14, wherein the first material, or the second material, or both comprise a composite material.
20. The method of claim 14, comprising conductively coupling the first material with the second material by penetrating a non-conductive exterior of the first material, or the second material, or both, to create the conductive path between the first and second plurality of conductive elements.
21. An imaging system, comprising:
image detection circuitry; and
a portable enclosure disposed about the image detection circuitry and at least substantially made of first and second electromagnetic interference (EMI) shielding materials, wherein the first EMI shielding material comprises a first plurality of conductive elements disposed in a first non-conductive material and the second EMI shielding material comprises a second plurality of conductive elements disposed in a second non-conductive material, wherein the first and second plurality of conductive elements are conductively coupled together via a conduction path through non-conductive surfaces of the first and second EMI shielding materials.
22. The system of claim 21, wherein the conductive path comprises an overmolded part in the first EMI shielding material, or second EMI shielding material, or both.
23. The system of claim 21, wherein the conductive path comprises an abraded surface of the first EMI shielding material, or second EMI shielding material, or both.
24. The system of claim 21, wherein the image detection circuitry comprises an x-ray detector panel.
25. The system of claim 21, wherein the portable enclosure has a panel-shaped geometry.
26. The system of claim 21, wherein the first non-conductive material, or the second non-conductive material, or both, comprises polycarbonate, and the first plurality of conductive elements, or the second plurality of conductive elements, or both, comprises carbon fibers, or carbon powder, or stainless steel fibers, or a combination thereof.
27. The system of claim 21, wherein the first EMI shielding material or the second EMI shielding material is a compounded plastic.
28. The system of claim 21, wherein the first EMI shielding material or the second EMI shielding material is a composite material.
29. A method for shielding electromagnetic interference (EMI) in an imaging system, comprising:
providing an EMI shielding enclosure comprising a first material having a non-conductive surface, wherein a second EMI shielding material is disposed on the non-conductive surface of the first material.
30. The method of claim 29, comprising painting the second EMI shielding material onto the non-conductive surface of the first material.
31. The method of claim 29, comprising electroplating or electroless plating the EMI shielding material onto the non-conductive surface of the first material.
32. The method of claim 29, wherein the second material comprises a metallic foil.
33. The method of claim 29, wherein the second material comprises a woven fabric.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A variable attenuator constructed and arranged to controllably attenuate a radiation beam in a lithographic apparatus, comprising:
two wedge-shaped prisms formed of refractive material located proximate each other, arranged so that in use the radiation beam passes through both prisms, and
wherein the attenuator is substantially planar.
2. The attenuator of claim 1, wherein the prisms are separated by a gap.
3. The attenuator of claim 1, wherein:
a first prism of the two prisms comprises a first face and a second face offset from parallel with each other by a prism angle;
a second prism of the two prisms comprises a first face and a second face offset from parallel with each other by the prism angle; and
the second face of the first prism is located adjacent and substantially parallel to the first face of the second prism so that the first face of the first prism and the second face of the second prism are substantially parallel.
4. The attenuator of claim 3, wherein the prism angle is in the range of approximately 3\xb0 to approximately 5\xb0.
5. The attenuator of claim 1, wherein the refractive index of each prism is approximately 1.5.
6. The attenuator of claim 1, wherein each prism is formed from calcium fluoride or quartz.
7. The attenuator of claim 1, wherein the attenuator is rotatable so as to change the angle at which the radiation beam strikes the prisms.
8. The attenuator of claim 1, wherein the prisms are rigidly connected to each other.
9. The attenuator of claim 1, wherein the prisms are uncoated.
10. A lithographic apparatus comprising:
an illumination system configured to condition a radiation beam;
a support constructed to support a patterning device, the patterning device being capable of imparting the radiation beam with a pattern in its cross-section to form a patterned radiation beam;
a substrate table constructed to hold a substrate;
a projection system configured to project the patterned radiation beam onto a target portion of the substrate; and
a substantially planar variable attenuator in the path of the radiation beam, controllable to variably attenuate the radiation beam, the variable attenuator comprising two wedge-shaped prisms proximate each other so that, in operation, the radiation beam passes through both prisms and the attenuator being rotatable so as to vary the angle at which the radiation beam strikes the prisms,
wherein the radiation beam is linearly polarised so that the polarisation direction is substantially parallel to the plane of incidence of the radiation beam on the attenuator.
11. The apparatus of claim 10, wherein the variable attenuator is rotatable over a range of 20\xb0.
12. The apparatus of claim 11, wherein the variable attenuator is rotatable between a first position, in which the radiation beam strikes the attenuator at an angle close to a Brewster angle of the material from which the prisms are formed, and a second position, in which the radiation beam strikes the attenuator at an angle far from the Brewster angle of the material from which the prisms are formed.
13. A device manufacturing method comprising:
projecting a radiation beam towards a substrate; and
passing the radiation beam through a substantially planar variable attenuator comprising two wedge-shaped prisms formed of refractive material, said prisms located proximate each other.
14. The method of claim 13, further comprising rotating the variable attenuator so as to vary the attenuation of the radiation beam.
15. The method of claim 13, wherein the prisms are separated by an gap.
16. The method of claim 13, wherein:
a first prism of the two adjacent prisms comprises a first face and a second face offset from parallel with each other by a prism angle;
a second prism of the two adjacent prisms comprises a first face and a second face offset from parallel with each other by the prism angle; and
the second face of the first prism is located adjacent and substantially parallel to the first face of the second prism so that the first face of the first prism and the second face of the second prism are substantially parallel.
17. The method of claim 16, wherein the prism angle is in the range of approximately 3\xb0 to approximately 5\xb0.
18. The method of claim 13, wherein the refractive index of each prism is approximately 1.5.
19. The method of claim 13, wherein each prism is formed from calcium fluoride or quartz.
20. The method of claim 13, wherein the prisms are rigidly connected to each other.
21. The method of claim 13, wherein the radiation beam is substantially plane polarised.
22. The method of claim 21, wherein the direction of polarisation of the radiation beam is substantially parallel to the plane of incidence of the radiation beam on the attenuator.
23. The method of claim 13, wherein the prisms are uncoated.
24. A device manufacturing method comprising:
passing a projection beam of radiation through a substantially planar variable attenuator comprising two adjacent wedge-shaped prisms formed of refractive material;
using a patterning device to impart the projection beam with a pattern in its cross-section; and
projecting the patterned beam of radiation onto a target portion of a substrate.
25. A method of controllably attenuating a radiation beam in a lithographic apparatus, comprising passing the beam through a substantially planar variable attenuator comprising two prisms arranged adjacent one another with a gap therebetween such that the radiation beam passes through both prisms.
26. A variable attenuator for selectively attenuating a radiation beam in a lithographic apparatus, the attenuator comprising:
a first prism comprising a first face and a second face offset from parallel with each other by a prism angle; and
a second prism comprising a first face and a second face offset from parallel with each other by the prism angle;
wherein the first and second prisms are rigidly connected to one another in such a way that the first face of the second prism is located proximate and substantially parallel to the second face of the first prism such that the first face of the first prism and the second face of the second prism are substantially parallel.