Spatial resolution measurements

Molecular sieves arc used in various applications in nuclear medicine. For example, small beads of zeolites were soaked in a solution of radioactive ions. These zeolite beads are employed as point source markers for the identification of anatomical landmarks and for gamma camera uniformity. Due to their small size and relatively high uptake they provide excellent devices for measuring spatial resolution, detector unifonnity and energy resolution.[54] Zeolites are also utilized as binding agents for toxic compounds and antioxidant for selenium, vitamins, and provitamins, and arc also used as mineral additive in various dietary strategies.[55]... 

Imagittg technique Labels Sigtuil measured Spatial resolution Timescale for observation Penetration Key use... 

Measurement spatial resolution (IFOVmeas or MFOV) The spatial resolution describing the minimum target spot size on which an accurate temperature measurement can be made. 

Quantum Focus Instruments InfraScope II Lab operated imager for microelectronics apphcations, features liquid nitrogen cooled InSb FPA (256 x 256 or 500 X 500 elements), automatic emissivity matrix measurement and compensation, full field temperature measurement, spatial resolution down to 2.5 pm, 60-Hz frame rate, interchangeable lenses. 

Hole response function, HRF - A measure of the measurement spatial resolution (IFOVmeas or MFOV) of a focal plane array-based infrared camera. 

Measurement spatial resolution, IFOVmeas or MFOV - The smallest target spot size on which an infrared camera can produce a measurement, expressed in terms of angular subtense (mrad). The slit response function (SRF) test is used to measure IFOVmeas in optomechanically scanned imagers. The hole response fiinction (HRF) test is used to measure IFOVmeas in optomechanically scanned imagers. 

IFOVmeas or MFOV measurement IFOV or measurement spatial resolution... 

The sensitivity of the luminescence IP s in the systems employed here decreases with increasing x-ray energy more strongly than in the case of x-ray film. Therefore, this phenomenon must be compensated by using thicker lead front and back screens. The specific contrast c,p [1,3] is an appropriate parameter for a comparison between IP s and film, since it may be measured independently of the spatial resolution. Since the absorption coefficient p remains roughly constant for constant tube voltage and the same material, it suffices to measure and compare the scatter ratio k. Fig. 2 shows k as a function of the front and back screen thickness for the IP s for 400 keV and different wall thicknesses. The corresponding measured scatter ratios for x-ray films with 0,1 mm front and back screens of lead are likewise shown. The equivalent value for the front and back screen thicknesses is found from the intersection of the curves for the IP s and the film value. 

The echo phase does not depend on the initial position of the nuclei, only on their displacement, vA, occurring in the interval between the gradient pulses. Analysis of the phase of the echo yields a measure of flow velocity in a bulk sample. Spatial resolution is easily obtained by the incorporation of additional imaging gradients. 

With SECM, almost any kind of electrochemical measurement may be carried out, whether voltaimnetric or potentiometric, and the addition of spatial resolution greatly increases the possibilities for the characterization of interfaces and kinetic measurements [, and 59]. It may be employed as an electrochemical tool... 

The atomic force microscope (ATM) provides one approach to the measurement of friction in well defined systems. The ATM allows measurement of friction between a surface and a tip with a radius of the order of 5-10 nm figure C2.9.3 a)). It is the tme realization of a single asperity contact with a flat surface which, in its ultimate fonn, would measure friction between a single atom and a surface. The ATM allows friction measurements on surfaces that are well defined in tenns of both composition and stmcture. It is limited by the fact that the characteristics of the tip itself are often poorly understood. It is very difficult to detennine the radius, stmcture and composition of the tip however, these limitations are being resolved. The AFM has already allowed the spatial resolution of friction forces that exlribit atomic periodicity and chemical specificity [3, K), 13]. 

Raman Microspectroscopy. Raman spectra of small soflds or small regions of soflds can be obtained at a spatial resolution of about 1 p.m usiag a Raman microprobe. A widespread appHcation is ia the characterization of materials. For example, the Raman microprobe is used to measure lattice strain ia semiconductors (30) and polymers (31,32), and to identify graphitic regions ia diamond films (33). The microprobe has long been employed to identify fluid iaclusions ia minerals (34), and is iacreasiagly popular for identification of iaclusions ia glass (qv) (35). 

The spatial resolution of the Raman microprobe is about an order of magnitude better than that obtainable using an infrared microscope. Measurement times, typically of a few seconds, are the same as for other Raman spectrographs. To avoid burning samples, low (5—50-mW) power lasers are employed. 

The electron probe X-ray microanalyzer provides extraordinary power for measuring the elemental composition of solid matter with pm lateral spatial resolution. The spatial resolution, limited by the spread of the beam within the specimen, permits pg samples to be measured selectively, with elemental coverage from boron to the actinides. By incorporating the imaging capability of the SEM, the electron probe X-ray microanalyzer combines morphological and compositional information. 

Overall, the AFM is a powerful tool that can provide very high force and spatial resolution measurements of adhesion and mechanical properties. The reader is... 

Depth-sensing nanoindentation is one of the primary tools for nanomechanical mechanical properties measurements. Major advantages to this technique over AFM include (1) simultaneous measurement of force and displacement (2) perpendicular tip-sample approach and (3) well-modeled mechanics for dynamic measurements. Also, the ability to quantitatively infer contact area during force-displacement measurements provides a very useful approach to explore adhesion mechanics and models. Disadvantages relative to AFM include lower force resolution, as well as far lower spatial resolution, both from the larger tip radii employed and a lack of sample positioning and imaging capabilities provided by piezoelectric scanners. 

With the use of appropriate transmission optics, high focusing of the laser light is carried out and the extension of the optical probe is considerably reduced. Accordingly, laser-based techniques offer the possibility of measurements of high spatial resolution. 

---