Condenser lenses

Most modern TEMs use a two-stage condenser lens system that makes it possible to... 

Instruments for the measurement of fluorescence are known as fluorimeters or spectrofluorimeters. The essential parts of a simple fluorimeter are shown in Fig. 18.1. The light from a mercury-vapour lamp (or other source of ultraviolet light) is passed through a condensing lens, a primary filter (to permit the light band required for excitation to pass), a sample container, a secondary filter (selected to absorb the primary radiant energy but transmit the fluorescent... 

Set the condensing lens in position at 2 cm from the slit jaws and at the correct height. 

Heat filter glass id. Secondary condensing lens system... 

Figure 5.15 shows a ray diagram for a light-optical projection microscope. The light source is placed behind a condenser system which collects the light which is diverging from the source and illuminates the specimen. The presence of the variable aperture near to the condenser lens permits control of the area of the specimen which is... 

Figure 5.17. Illustrating the principle of STEM image formation using two pairs of scan coils between the second condenser lens and the upper objective polepiece. (Reproduced by permission of Williams and...

Fig. 2. (a) Ray diagram in the electron microscope under imaging (microscopy) conditions. E electron source C condenser lens S sample O objective lens bfp back focal plane of O I intermediate lens P projector lens, (b) Structural imaging, diffraction and compositional functionalities of TEM. 

Fig. 6. The Sofica LS photometer 1 - Hg Pump cooled by high pressure water, 2 - total reflection prism, 3 - achromatic condensing lens, 4 - wavelength filters, 5 - glass diffuser,...

Fig. 7. The Bleeker small angle LS photometer5 8h La - light source, LI condenser lens,...

Figure 16. A refractive lens imaging system using partially coherent light, condenser lens and objective lens.

Numerical aperture is thus a quantitative measure of the "acceptance" angle of a lens. Likewise the numerical aperture of the condenser lens in Figure 16 is defined as... 

The electron microscope is an optical instrument with magnification much higher than any other known instrument (magnifications of up to 100000 are obtainable, compared with 1000 for the ordinary compound microscope) Essentially, an electron microscope consists of a source of electrons, sometimes called an electron gun (negative high voltage), and a series of devices serving as "lenses the first is a condenser lens, then an objective and a third lens which.functions as a... 

An array of 10- i,m microlenses was fabricated from the adhesion of an aminated silicasol on a poly[methyl(phenyl)silane-co-methyl(3,3,3-tri-fluoropropyl)silane] (CF3PMPS) film patterned by UV light irradiation.132 By soaking the UV-patterned polysilane film into the sol-gel solution, a convex xerogel layer adhered only to the UV-exposed poly silane, which was cured to form a glass that functioned as a condensing lens. 

OBJECTIVE LENS (15X) ROTATABLE X-Y STAGE CONDENSER LENS (15X)... 

The specimen to be viewed is first fixed with alcohol or formaldehyde, embedded in wax and then cut into thin sections. A section is illuminated from below with the beam of light being focused on to it by the condenser lens. The incident light that passes through the specimen is then focused by the objective lens on to its focal plane, creating a magnified image. 

In dark-field microscopy, light from the condenser lens is directed at an angle on to the specimen such that only light which has been refracted or diffracted by the specimen enters the objective lens and forms an image. 

Microscopes. There are two basic modes of operation for X-ray analysis in a modern-day AEMs with a static (or flood) beam and with a rastered beam. This instrument is essentially a conventional TEM with either (a) scanning coils to raster and focus the beam or (b) an extra NminiN (or objective pre-field) condenser lens to provide a small (nm-sized) cross-over of a static beam at the objective plane. Some AEM configurations contain both scanning coils and a third condenser lens whilst others may have only one of these. In either condition, a small-sized electron probe can be obtained as a static or a rastered beam. The basic electron-optical principles which provide nanometer-sized beams for microanalysis are similar to those for electron microdiffraction which are well described by Spence and Carpenter [19]. 

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