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Microscope Requirements for CL8200 research.
Microscope Objectives, should have the highest NA possible. The NA is a measurement of the light collecting
ability of the lens. Cathodoluminescense intensity is intrinsic to the material and cannot be "Turned Up" like
normal microscope illumination. More KV and current in the electron beam will damage the specimen.
The TP5 top plates have a effective WD to the sample of slightly less than 5mm.
The TP9 top plates and analytical top plate has an effective WD of slightly less than 9mm.
Objectives should be chosen that are as close to this figure as possible. The longer the WD above 5mm or 9mm
the less light that will be collected and the dimmer the image.
Microscope Condenser.
The sample plane is approximately 25mm above the bottom of the chamber so should be able to focus at greater
than 25mm.
The chamber & top plate weigh about 2.5Kg so the focusing mechanism needs to be able to withstand this mass
without causing defocusing.
Optical center of stage is 75mm from back of chamber so rear limb of microscope must be 80mm or greater from
optical center of the microscope.
The chamber top plate clearance height is 45mm. Focusing adjustment from bottom of lens to stage must be more than
45mm.
Remember simple is better. The fewer optical components in the optical chain the better. Light is lost at every
optical interface. For camera work it is best if 100% of the light is diverted to the camera. This can make the
differance from using a standard microscope camera to a very expensive coolled one.
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