Scattering basic setup

Instrumentation. The basic setup of a neutron scattering experiment is depicted in Fig. 5.157. 

Figure 9.2 Basic setup of a scattering experiment. The incident beam (plane wave) irradiates the sample. The intensity of the scattered beam (spherical wave) is measured with a detector at an angle of 26.

C. The Basic Elements of the Experimental Setup. The basic elements of TRRR experiments are a photolysis source a laser probe source (whose scattered radiation by the photolabile sample contains the vibrational spectra of the photodecomposed sample and its transients) a dispersing instrument (e.g., a spectrometer) and an optical multichannel analyzer (OMA) system used as a detector. 

In the following, the basics of reflectivity theory and the setup for scattering experiments are presented. The advantages and disadvantages compared to other... 

It is not in the scope of the present chapter to review all possible experimental setups for the various types of Raman scattering classical, microprobe, Fourier transform (FT), coherent anti-Stokes (CARS), surface enhanced (SERS), hyper (HRS), photo-acoustic (PARS), and so forth (see, e.g.. Refs. 29-31). A basic Raman-scattering instrument requires a laser-light source, an appropriate sample holder, a sample illumination optical unit, a scattered-light collection optical unit (these two may be combined in one system), a disperser (spectrometer) or an interferometer, a light detection unit, a recorder, and an appropriate microcomputer able to drive, control, and record all of the experimental parameters as well as the results and their processing. 

Figure 8.2. The basic X-ray setup for the study of deformation at a synchrotron. The intensity of the incident X-ray beam is measured in an ionization chamber (/g). Thereafter it penetrates the sample which is subjected to mechanical load. At a distance, A, behind the sample, the detector is recording the scattering pattern. In its center the detector is protected by a beam stop. It is equipped with a PIN-diode (7 ) which records the intensity of the attenuated beam...

After a short description of the experimental setup in the previous section, we now focus on the basic mathematical description of the intensity measured in a SAXS experiment. X-rays are electromagnetic waves. Assume an incident plane wave with flux 7o, which is scattered by the electrons in the sample. The scattered spherical waves interfere with each other, resulting in an angle-dependent flux J of scattered radiation. The flux of the incident plane wave corresponds to energy transmitted per unit area per unit time and the flux J of the scattered radiation to energy transmitted per unit solid angle per unit time. Now the differential scattering cross section or scattered intensity is defined as the ratio... 

A basic TIRM setup consists of a laser, a prism that either forms the bottom of the measurement cell or is attached via an index matching material to the glass bottom of the cell, and an inverted optical microscope equipped with a sensitive photon detector to collect the scattered laser light (Figure 3.12). 

---