Beam path

When directed towards the test piece the laser beam passes through a centre hole in a 45 degree fixed-angle mimor. Between this mirror and the test piece the laser beam and the flourescence follow a common beam path. A photodetector is aimed at the 45 degrees angle mirror and, therefore, looks along the laser in this common beam path, see Fig 3. 

The aim of the experiment was to study the transmission of a signal through the weld and to measure the frequency and phase dependencies of parameters of acoustic signals from the angle of incidence and beam path within the weld volume. One of the shift of the spectral characteristics the signal is shown in Figure 4(a,b). 

The echo height of side drilled holes was measured at a constant beam path length as shown in Fig. 1. 

The echo directivity for surface SH Wave probes and SH Wave angle probes was measured. The experiment was carried out by measuring the echo height from side drilled holes of different depths at a constant beam path length. The calculation of echo height was based on a point sound source on the test surface in different phases. The experiment and the calculation were compared. The effects of the frequency, height of... 

Molecular beam sample introduction (described in section (Bl.7.2)). followed by the orthogonal extraction of ions, results in improved resolution in TOP instruments over eflfrisive sources. The particles in the molecular beam typically have translational temperatures orthogonal to the beam path of only a few Kelvin. Thus, there is less concern with both the initial velocity of the ions once they are generated and with where in the ion source they are fonned (since the particles are originally confined to the beam path). 

Figure Bl.17.2. Typical electron beam path diagrams for TEM (a), STEM (b) and SEM (c). These schematic diagrams illustrate the way the different signals can be detected m the different instmments.

The frill width at half maximum of the autocorrelation signal, 21 fs, corresponds to a pulse width of 13.5 fs if a sech shape for the l(t) fiinction is assumed. The corresponding output spectrum shown in fignre B2.1.3(T)) exhibits a width at half maximum of approximately 700 cm The time-bandwidth product A i A v is close to 0.3. This result implies that the pulse was compressed nearly to the Heisenberg indetenninacy (or Fourier transfonn) limit [53] by the double-passed prism pair placed in the beam path prior to the autocorrelator. 

Figure 3 Typical beam path configuration for collecting an FTIR spectrum using an attenuated total reflectance element Iq is the incident infrared beam, f is the exiting beam.

The deuterium arc continuum travels the same double-beam path as does the light from the resonance source (see Fig. 21.9). The background absorption affects both the sample and reference beams and so when the ratio of the intensities of the two beams is taken, the background effects are eliminated. 

The absorption problems for other detectors may be considered under three headings (1) attenuation along the beam path, (2) attenuation by the detector window, (3) absorption by the detecting medium. The results of absorption calculations (1.9) in Table 2 1 show the importance of these problems and suggest ways of dealing with them. 

The idealized calculations of the efficiency of the parts of an x-ray spectrograph (4.3, 4.4) can be modified to apply to a laboratory instrument if account is taken of the pulsating character of the applied voltage, the polychromatic nature of the x-ray beam, and the absorption in the beam path. 

Fig. 3. Schematic beam path of a phase-measurement interference microscope (PMIM, Fizeau optics). The beam partially reflected at the reference plane and at the sample surface interfere with each other while the reference plane is moved by the piezoelectric transducer for automatic phase determination. A reflectivity of at least 1% is required for the sample surface...

Figure 5 shows the laser beam path reflected by the torsional cantilever. The incident angle is y on the cantilever surface before the cantilever torsion. When the torsional angle of the cantilever is 6i, reflection ray turned an angle a. Their relationship can be expressed by... 

Similar reflection plates are used for recording ultraviolet-visible and Raman spectra of matrix isolated molecules, although the traditional beam path passing through transparent quartz windows is more frequently used in UV spectrometers. Sapphire rods, which are placed in the spectrometer cavity, are applied as targets in matrix esr studies. 

A computer-controlled motorized translation stage mounted with a retro-reflector is used to vary the pump laser beam path relative to the probe laser beam path and this controls the relative timing between the pump and probe laser beams. Note that a one-foot difference in path length is about 1 ns time delay difference. The picosecond TR experiments are done essentially the same way as the nanosecond TR experiments except that the time-delay between the pump and probe beams are controlled by varying their relative path lengths by the computer-controlled motorized translation stage. Thus, one can refer to the last part of the description of the nanosecond TR experiments in the preceding section and use the pump and probe picosecond laser beams in place of the nanosecond laser beams to describe the picosecond TR experiments. 

V Accelerating voltage (V) 1 Current in Helmholtz coils (A) r Radius of electron beam path (m)... 

Measuring and Using Numbers Enter the accelerating voltage values from Data Table 2 into Data Table 3. Using the values for the radius of the electron beam path (r) from Data Table 2, calculate the corresponding r2 values and enter them into Data Table 3. 

Compton profile. Furthermore the contribution of the multiple scattered photons to the measured spectra has to be taken into account (for example by a Monte Carlo simulation [6]). Additionally one has to take heed of the fact that the efficiency of the spectrometer is energy dependent, so the data must be corrected for energy dependent effects which are the absorption in the sample and in the air along the beam path, the vertical acceptance of the spectrometer and the reflectivity of the analyzing crystal. 

Gian laser polarizer in the 365-nm beam path. The so-called parallel and perpendicular polarizations are referenced to the ion TOF axis. 

FIGURE 6.3 (a) Cross section of human eye with indication of optical beam paths propagating back and... 

These disadvantages are overcome by the so-called dance-floor principle which is supposed to become the major beamline construction principle of the future. Figure 4.11 shows a dance floor during the construction of the beamline hall at the ANSTO neutron-scattering facility at Lucas Heights near Sydney, Australia. The dance floor is featuring an extremely plane and hard floor surface from granite. Optical components, detectors and sample chambers are mounted on supports with a flat lower surface. While compressed air is blown into the gap between the dance floor and the area of support, components are easily moved and adjusted in the optical beam path. 

V is the chamber volume, L is the light beam path length, A is the sample area, and T is the transmittance. 

Fig. 10.3. Beam compressor, DPM, and experimental chambers layout. The left inset shows the beam path inside of the DPM, while the right inset shows the two AR dielectric plates (the line shows the beam path between them)...

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