Ft-Ir Spectrometer Lab Report

The main part of the FT-IR spectrometer is a Michelson interferometer composed of a beam-splitter and two mirrors: one is fixed- and other is moving which produce the interference pattern.

2.2.4. Transmission electron microscope (TEM)

TEM is a technique which operates on the same basic principles as that of a light microscope, but uses electrons instead of light. The lower wavelength of electrons compared to that of light, results in better resolution of the TEM image compared to a light microscope image. TEM uses electromagnetic lenses rather than glass lenses to focus the electrons into a very thin beam. The electron beam pases through the specimen, depending on the density of the material, out of which some are scattered and disappears from the beam. At the bottom of the microscope the unscattered electrons hit a fluorescent screen, which gives a "shadow image" of the specimen with its different parts displayed in varied darkness depending on their density. The image can be studied directly by the operator or photographed with a camera. The structures of the self assembled particles were studied using Zeiss-Carl (Libra-120) transmission electron microscope at an accelerating voltage of 120 kV. The schematic of a typical TEM is shown in Figure 2.5. Figure 2.5: Schematic diagram of Tunneling electron

During the two years in the reactor, a small percentage of the atoms in the cobalt slug are converted into cobalt-60 atoms. Specific activity is usually limited to about 120 Ci/g of cobalt. After irradiation, the capsules containing the cobalt slugs are further encapsulated in corrosion resistant stainless steel to finally produce the finished source pencils in a form such that gamma radiation can come through but not the radioactive material (cobalt-60) itself. The source pencils are arranged in the form of a cylinder, over the source rack of the industrial