Depth scanning

Kanngiesser et al. (2003) demonstrated the principle of localized detection and sample depth-scanning for synchrotron radiation-induced XRE Vincze et al. (2004) gave the full characterization of polycapillary-based confocal XRF and its applications for 3D trace-element analysis. 

Figure 7.9 Superimposed spectra during the depth scan of an ARA membrane (A) and (A ) intensity of the nitrate band in the nitric acid solution and within the membrane respectively, (B) nitrate absence in the hydrochloric solution, (C) water intensity, (D-F) membrane matrix intensities.

Figure 7.12 Superimposed spectra during the depth scan of a Nafion membrane (A) water (OH stretching), (B) symmetric and anti-symmetric stretching CH3, (C) CO stretching (methanol), (D) CF2 symmetric stretching (membrane matrix).

P. J. Caspers, G. W. Lucassen, H. A. Bmining, and G. J. Puppels, "Automated depth-scanning confocal Raman microspectrometer for rapid in vivo determination of water concentration profiles in human skin," Journal of Raman Spectroscopy, vol. 31, pp. 813-818, 2000. 

DEPTH SCANNING A POSSIBLE TOOL TO IMPROVE ACCURACY 4.1. Calibration method and measuring procedure... 

Calibration is performed on phantoms (Fig. 4) by recording the depth scanning profiles on a standard lobe pixel placed at 5 contiguous distances (D) from the neck surface. Each profile (Fig 5) is then fitted with the gaussian function ... 

The depth scanning profile on the entire thyroid lobe is given approximately by the sum of the contributions from the 5 lobe pixels. Thus, from eqs. (8) and (9), we have... 

FIGURE 5. Typical depth scanning profile determined on a lobe pixel. For key to symbols see Figure 4. Continuous line is the best-fit gaussian function. 

FIGURE 6. Left different arrangements of the same lobe phantom (inner diameter 12 mm iodine content 10.2 mg) within the neck phantom. Center corresponding depth scanning profiles obtained by rotation of the source-collimator assembly (see text) continuous lines are the best-fit curves dashed lines represent the components due to each lobe pixel. Right effective and calculated depth distributions of iodine (dashed and continuous lines, respectively). 

FIGURE 7. Example of depth scanning on each thyroid lobe of a normal volunteer. The best-fit curves and the components are represented with continuous and dashed lines, respectively. Counting time was 100 s for each point the estimated dose absorbed by the thyroid was about 15 mrem. 

A Scan at 7mm depth B Scan at 10mm depth C Scan at 13mm depth Fig. 11 Tomography scans of an internal shrinkage at different depths (A B C)... 

Figure 5 shows the display in the measure mode. It consists of a detailed A-scan window and a number of smaller windows for display parameters and inspection parameters. The A-scan display may be used as a stand-alone tool or as a tool for measuring parameters required for a specific inspection, e.g. probe parameters, reference echoes, and depth compensation with automatic transfer to the data set. 

Fig. 6, aB-scan of a 15 mm thick sandwich with Nomex cores and GFRP-skins, shows clearly the depth of the two defects in the core [4]. A HILL-SCAN 3010 board and a broadband probe (0,8 to 3 MHz) were used. In regions without defects, the backwall-echo is indicated. 

A number of individual radar scans have been joined together Variations in cover depth give rise to variations in arrival time for the wave reflected from the reinforcing bars... 

Fig. 27. Scanning electron micrograph (a) and cross-sectional comparison (b) of screen and depth filters both having a nominal particulate cut-off of 0.4 flm. The screen filter (a Nuclepore radiation track membrane) captures particulates at the surface. The phase-inversion ceUulosic membrane traps the...

Penetration—Indentation. Penetration and indentation tests have long been used to characterize viscoelastic materials such as asphalt, mbber, plastics, and coatings. The basic test consists of pressing an indentor of prescribed geometry against the test surface. Most instmments have an indenting tip, eg, cone, needle, or hemisphere, attached to a short rod that is held vertically. The load is controlled at some constant value, and the time of indentation is specified the size or depth of the indentation is measured. Instmments have been built which allow loads as low as 10 N with penetration depths less than mm. The entire experiment is carried out in the vacuum chamber of a scanning electron microscope with which the penetration is monitored (248). 

Ion Implantation Systems. An ion implantation system is used to accelerate ionized atomic or molecular species toward a target sample. The ionized species penetrates the surface of the sample with the resulting depth profile dependent on the implanted species mass, energy, and the sample target s tilt and rotation. An implanter s main components include an ionizer, mass separator, acceleration region, scanning system, and sample holder (168). 

The distribution of impurities over a flat sihcon surface can be measured by autoradiography or by scanning the surface using any of the methods appropriate for trace impurity detection (see Trace and residue analysis). Depth measurements can be made by combining any of the above measurements with the repeated removal of thin layers of sihcon, either by wet etching, plasma etching, or sputtering. Care must be taken, however, to ensure that the material removal method does not contaminate the sihcon surface. 

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