Patent Number: 
Section: claims

1. An apparatus for use with an electron beam for imaging a sample, the apparatus comprising:a down-conversion detector configured to detect an electron microscopy signal generated by the electron beam incident on the sample;a direct bombardment detector adjacent to the down-conversion detector and configured to detect the electron microscopy signal; anda mechanism selectively exposing the direct bombardment detector to the electron microscopy signal. 2. The apparatus of claim 1, wherein the down-conversion detector comprises a scintillator. 3. The apparatus of claim 2, wherein the scintillator includes a YAG scintillator. 4. The apparatus of claim 2, wherein the scintillator includes a polycrystalline scintillator. 5. The apparatus of claim 1, wherein the down-conversion detector comprises a plurality of pixels. 6. The apparatus of claim 1, wherein the down-conversion detector includes a charge-coupled device (CCD). 7. The apparatus of claim 1, wherein the down-conversion detector includes a CMOS image sensor. 8. The apparatus of claim 1, wherein the down-conversion detector is configured to focus the electron microscopy signal. 9. The apparatus of claim 1, wherein the down-conversion detector is configured to identify of a region of interest of the sample. 10. The apparatus of claim 1, wherein the direct bombardment detector comprises a plurality of active pixel sensors. 11. The apparatus of claim 1, wherein the mechanism comprises a shutter positionable in a propagation path of the electron microscopy signal upstream to the direct bombardment detector. 12. The apparatus of claim 1, wherein the mechanism comprises a steering device to steer the electron microscopy signal between the down-conversion detector and the direct bombardment detector. 13. The apparatus of claim 1, wherein the down-conversion detector and the direct bombardment detector are integrated into a single camera. 14. The apparatus of claim 1, further comprising an optical fiber plate coupled to the down-conversion detector. 15. The apparatus of claim 1, further comprising a Faraday plate configured to measure total cumulative dose of the electron microscopy signal. 16. The apparatus of claim 1, further comprising a Faraday plate configured to measure instantaneous dose of the electron microscopy signal. 17. A apparatus for use with an electron beam for imaging a sample, the apparatus comprising:a down-conversion detector configured to detect an electron microscopy signal generated by the electron beam incident on the sample;a direct bombardment detector adjacent to the down-conversion detector and configured to detect the electron microscopy signal; andwherein the down-conversion detector and the direct bombardment detector are integrated into a single camera. 18. A method of producing an image of a sample using an electron beam, the method comprising the steps of:a) applying the electron beam to the sample for generating an electron microscopy signal;b) detecting the electron microscopy signal by a down-conversion detector to obtain a detection result;c) determining at least one detection parameter based on the detection result of the down-conversion detector; andd) detecting the electron microscopy signal by a direct bombardment detector using the detection parameter. 19. The method of claim 18, wherein the sample includes a biological matter. 20. The method of claim 18, wherein the detection parameter includes focusing information of the electron microscopy signal. 21. The method of claim 18, wherein the detection parameter includes a region of interest of the sample. 22. The method of claim 18, further comprising a step of steering the electron microscopy signal towards the direct bombardment detector for detecting the electron microscopy signal by the direct bombardment detector. 23. The method of claim 18, further comprising a step of blocking the direct bombardment detector from exposure of the electron microscopy signal before the detection parameter is determined. 24. The method of claim 18, further comprising a step of cooling the down-conversion detector to below ambient temperature. 25. The method of claim 18, further comprising a step of cooling the direct bombardment detector to below ambient temperature. 26. An apparatus for use with an electron beam for imaging a sample, the apparatus comprising:a direct bombardment detector configured to detect an electron microscopy signal generated by the electron beam incident on the sample;a beam current measuring device to be located adjacent to the direct bombardment detector; anda mechanism configured to selectively prevent the electron microscopy signal from being incident on the direct bombardment detector. 27. The apparatus of claim 26, wherein the beam current measuring device includes a Faraday plate. 28. The apparatus of claim 26, wherein the mechanism includes a shutter positionable in the propagation path of the electron microscopy signal upstream to the direct bombardment detector. 29. A method of producing an image of a sample using an electron beam and a direct bombardment detector, the method comprising the step of:a) applying the electron beam to the sample for generating an electron microscopy signal;b) detecting the electron microscopy signal by a beam current detector to obtain a detection result;c) determining at least one detection parameter based on the detection result of the beam current detector; andd) detecting the electron microscopy signal by the direct bombardment detector using the detection parameter. 30. The method of claim 29, wherein the sample includes a biological matter. 31. The method of claim 29, wherein the detection parameter includes a dose of the electron microscopy signal. 32. The method of claim 31, wherein the dose includes an instantaneous dose applied to the direct bombardment detector. 33. The method of claim 31, wherein the dose includes a total cumulative dose applied to the direct bombardment detector. 34. The method of claim 29, further comprising a step of setting a dose of the electron beam applied to the sample. 35. The method of claim 29, further comprising a step of positioning a moveable shutter to selectively block the electron microscopy signal from the direct bombardment detector based on the detection parameter.