Angle conventions

Specular reflection is light reflected at a single angle (conventional reflection). 

The spectral radiance (p) is defined as the radiant power (or photon flux density) emitted per unit source area per unit sohd angle (conventionally expressed in W/m /sr). 

A-2. Angle Conventions for the Incident and Scattered Light in THE Beam Coordinate System... 

Torsion-Angle Conventions Referenced to the Phosphodiester Backbone... 

For conventional probes, acoustic verification aims at characterizing the beam pattern, beam crossing, beam angle, sensitivity, etc., which are key characteristics in the acoustic interaction between acoustic beam and defect. For array transducers, obviously, it is also a meaning to check the acoustic capabilities of the probe. That is to valid a domain (angle beam, focus, etc.) in which the probe can operate satisfactorily. 

There are some subtleties with respect to the physicochemical meaning of the contact angle equation, and these are taken up in Section X-7. The preceding, however, serves to introduce the conventional definitions to permit discussion of the experimental observations. 

The more conventional, energy domain fonnula for resonance Raman scattering is the expression by Kramers-Heisenberg-Dirac (KHD). The differential cross section for Raman scattering into a solid angle dD can be written in the fomi... 

Figure Bl.17.3. STEM detectors (a) conventional bright and dark-field detectors, electrons are detected according to their different scattering angles, all other positional infonnation is lost (b) positional detector as developed by Haider and coworkers (Haider etal 1994).

Here tire are tire amplitudes of tire hannonics of tire density, is tire wavenumber and tire are arbitrary phase angles, which are necessary for a complete tlieoretical description of tliis stmcture (see section C2.2.3.4). The z direction is, by convention, nonnal to tire layers. 

From now on we shall describe the scattered light by Eq, (10.30) exclusively, rather than considering the separate components. We shall also consider 0 only in the xy plane, in which case we use the symbol 6 to describe this angle. By convention, the incident light approaches the scattering dipole from 6 = 180°, and the transmitted light leaves the sample at 0 = 0°. 

Brightness. This is defined as the power emitted per unit area of the output mirror per unit solid angle and is extremely high compared with that of a conventional source. The reason for this is that, although the power may be only modest, as in, for example, a 0.5 mW helium-neon gas laser, the solid angle over which it is distributed is very small. 

Fig. 3. Conventions for naming axes and angles for a unit cell.

Position Sensitive Detectors. By replacing the scintillation detector in a conventional powder diffractometer with a Position Sensitive Detector (PSD), it is possible to speed data collection. For each x-ray photon received a PSD records the angle at which it was detected. Typically, a conventional scintillation detector records x-ray photons in a range of a few hundredths of a degree at a time. A PSD can measure many degrees (in 20) of a powder pattern simultaneously. Thus, for small samples, data collection, which could require hours with a conventional detector, could take minutes or even seconds with a PSD. 

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