Plane detector geometry

In reflectivity experiments, the source and detector geometry are chosen so that the scattering vector Q is parallel to the z-axis (perpendicular to the plane of the monolayer), as shown in Fig. 7. The reflectivity R(Q) is then given by ... 

Fig. 1.8 Experiment geometry, Ewald sphere, and reciprocal space. The stimple is placed in the center of the sphere. Its structure is defined in the real-space coordinates, r = (ri, r2, r3>. The origin of reciprocal space, s = (s 1, 2,. 3). is attached to the surface of the Ewtdd sphere. The orientation of its axes is strictly fixed to the orientation of the sample space r. Each point on a plane detector (for clarity shifted to a position in front of the sphere) ctin be addressed by the two coordinates scattering angle, 20, and azimuthed angle, (p. The mapping of these two coordinates into reciprocal space is mediated by means of the surface of the Ewald sphere [60]...

Mattauch-Herzog geometry, which simultaneously focuses all resolved masses onto one plane, allowing the integrating properties of an ion-sensitive emulsion to be used as the detector. Although electrical detection with an electron multiplier can be applied, the ion-sensitive emulsion-coated glass photographic plate is the most common method of detection and will be described in this article. 

Since we use the laser geometry where both lasers are parallel and in the plane of the detector, the resultant 3D distributions are cylindrically symmetric about the laser polarization, and thus the angular distribution can be characterized by the single variable qj. When plotting the full angular distribution 1(0a) = P(u)[l + / P2(cos0d)]/deteCtion(0difference between the shapes of the m,j =0 and rrij = 2... 

Nowadays, forward geometry instruments are often constructed to be used in combination with an (optional) array detector, e.g., the JEOL HX-110 (EB), the Thermo Finnigan MAT 900 (EB) and the Micromass Autospec (EBE) instruments can be equipped in that way. The array detector is then located at the focus plane of the magnet, but different from the Mattauch-Herzog design it only covers a comparatively small m/z range simultaneously (Chap. 4.8). 

Multi-row detector systems are referred to as cone-beam systems. With a moving conveyor they become helical cone-beam systems. The cone-beam designation is in contrast to the fan-beam geometry used in Figures 3 and 4, where the source and detectors are aU in a single plane. 

In the experimental geometry used in this study, the distribution of scattered intensity measured by the detector is the two dimensional Fourier transform of the cross section of the electron density correlation function with a plane perpendicular to the extrusion direction (11). 

Figure 3.6 Schematicofa double-focusing sector field mass spectrograph with Mattauch-Herzog geometry with a linear imaging curve (double focusing for ions of all masses simultaneously) modified field combination with 70°. In the mass spectrograph, photographic ion detection or focal plane array detectors are used for quasi-simultaneous detection of separated ion beams. (H. Kienitz (ed.), Massen-spektrometrie (1968), Verlag Chemie, Weinheim. Reproduced by permission of Wiley-VCH)...

The primary act in a photochemical reaction is absorption of a quantum of radiation by the photoactive molecule. In a quantitative study, therefore, a radiation source of known intensity and frequency a suitable cel for the photolyte and an appropriate detector of light intensity are absolutely necessary for the determination of rates of reaction. To avoid experimental error due to geometry of the reaction cell, the best arrangement is to have a plane parallel beam of monochromatic radiation, incident upon a flat cuvette with proper stirring arrangement, as given in Figure 1.2. 

Fig. 18. Geometry of fan-beam coherent scatter computed tomography. A fan beam is used to illuminate one object slice. The central detector row (in the plane of the drawing) receives the transmitted radiation while the out-of-plane rows receive only scattered radiation. The coordinate represents the projection angle whereas...

---