Crossed-beam imaging

Figure 1. Cross-section weak-beam images of the same area of a MOVPE-grown ZnO layer on Al203(0001) with a 40 nm GaN buffer layer taken with (a) g = 0002 under g,3g conditions and (b) g = 11-20 under g,3g conditions.

The crossed-beam geometry can also be used to map the angular distribution of chemiluminescent reaction products. The videochemiluminescence technique has been introduced for this purpose. It was exemplified on the Ba( Pi) 4-N2O BaO(A n)-f N2 reaction where the angular distributions of the long-lived BaO (A n) product were imaged using a CCD camera [37, 38]. 

Fig. 3.82 Pore creation through 13 tm thick PET membranes exposed to 254 and 312 nm wavelengths for 1 h. Ion beam of 58Ni with incident energy 10.7 MeV/u (1 h, 254 nm) 9.1 MeV/u (15 h, 254 nm). Etching occurs at the both faces, d is the pore diameter measured with AFM (surface image) and he is the depth of etching penetration through the membrane measured with SEM (cross-section image) and fe = etching time. Reproduced with permission from [173]. Copyright 2007. Elsevier...

Other new techniques include 3D-scanning, speckle reduction imaging and cross beam techniques. The gray-scale ultrasound is highly useful in the differential diagnosis of the most common benign lesions, namely simple cysts and hemangiomas. 

SEM combined with focused ion beams (FIB), usually gallium ion beams, are used in order to obtain the cross sectional images near the sample surface. The sample surfaces can be etched in a nanoscale by spattering the surface atoms with... 

Crossed molecular beam studies using imaging detection of products have been restricted to the determination of non-state-selective differential cross-sections, in which an atomic product is probed using (1 + 1) REMPI, or in which a molecular product is probed by universal photoionization. This is because molecular beams are normally skimmed and typical product densities per quantum are only of the order lO cm this approaches the sensitivity limit of state-selective REMPI. In addition, with the exception of (1 + 1) REMPI, the probe laser must be focused, thus creating a very small interaction volume that yields extremely low count rates. The reaction F + CU4 (see Liu (2001)) was the first to be studied by (2 + 1) REMPI in a crossed molecular beam experiment to measure state-selected differential cross-sections. The first study of a neutral bimolecular reaction using a crossed-beam arrangement and 1 + 1 REMPI detection of an atomic product was carried out for... 

Figure 23.12 Crossed-beam apparatus for investigating the dynamics of elementary reactions using imaging techniques. Adapted from Ahmed et at, Phys. Chem. Chem. Phys., 2000, 2 861, with permission of the PCCP Owner Societies...

Fig. 7.25. Cross-sectional focused ion beam image of a hillock penetrating through the surface of a 1 /rm thick A1 film on a relatively thick (100) Si substrate. Reproduced with permission from Kim et al. (2000).

Figure 1.1 Cross-sectional image of how the isotopic constituents of a Ti" " ion beam are separated while passing through a Magnetic Sector mass filter. Note The magnetic field direction is perpendicular to the trajectory plane of the beam, i.e. perpendicular to the page and = 1. The original inslmments recorded mass separated images on photographic plates, as is shown.

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