Showing papers in "Review of Scientific Instruments in 1995"
TL;DR: In this paper, a straightforward experimental setup for phase contrast imaging is proposed and used to record holographic images from organic samples of 10-100 pm at energy lo-50 keV with the contrast up to 50%-100%.
Abstract: Coherent properties of the x-ray beam delivered at the ESRF allow the observation of very weak perturbations of the wave front, resulting in the phase contrast. A straightforward experimental setup for phase contrast imaging is proposed and used to record holographic images from organic samples of 10-100 pm at energy lo-50 keV with the contrast up to 50%-100%. The theory of phase contrast imaging is considered and some theoretical estimations are made to reveal the performance of the proposed technique in terms of resolution, sensitivity, geometrical requirements, and ehergy range applicability. It is found that for carbon-based fibers a detectable size with 2% contrast is 0.1 ,um for 10 keV and - 1 pm for 100 keV, It is demonstrated that the fine interference structure of the image is very sensitive to the shape, density variation, and internal structure of the sample. Some prospects for the practical use and future development of the new coherent techniques such as phase contrast microscopy, microtomography, holography, and interferometry at high energies are also discussed. 0 I995 American Institute of Physics.
1,413 citations
TL;DR: In this paper, an experimental setup has been constructed for simultaneous measurements of the frequency, the absolute Q factor, and the amplitude of oscillation of a quartz crystal microbalance (QCM).
Abstract: An experimental setup has been constructed for simultaneous measurements of the frequency, the absolute Q factor, and the amplitude of oscillation of a quartz crystal microbalance (QCM). The technical solution allows operation in vacuum, air, or liquid. The crystal is driven at its resonant frequency by an oscillator that can be intermittently disconnected causing the crystal oscillation amplitude to decay exponentially. From the recorded decay curve the absolute Q factor (calculated from the decay time constant), the frequency of the freely oscillating crystal, and the amplitude of oscillation are obtained. All measurements are fully automated. One electrode of the QCM in our setup was connected to true ground which makes possible simultaneous electrochemistry. The performance is illustrated by experiments in fluids of varying viscosity (gas and liquid) and by proteinadsorptionin situ. We found, in addition to the above results, that the amplitude of oscillation is not always directly proportional to the Q factor, as the commonly used theory states. This puts limitations on the customary use of the amplitude of oscillation as a measure of the Q factor.
1,172 citations
TL;DR: In this article, a fast and non-destructive method for the evaluation of the spring constant which relies solely on the determination of the unloaded resonant frequency of the cantilever, a knowledge of its density or mass, and its dimensions is proposed.
Abstract: The determination of the spring constants of atomic force microscope (AFM) cantilevers is of fundamental importance to users of the AFM. In this paper, a fast and nondestructive method for the evaluation of the spring constant which relies solely on the determination of the unloaded resonant frequency of the cantilever, a knowledge of its density or mass, and its dimensions is proposed. This is in contrast to the method of Cleveland et al. [Rev. Sci. Instrum. 64, 403 (1993)], which requires the attachment of masses to the cantilever in the determination of the spring constant. A number of factors which can influence the resonant frequency are examined, in particular (i) gold coating, which can result in a dramatic variation in the resonant frequency, for which a theoretical account is presented and (ii) air damping which, it is found, leads to a shift of -4% in the resonant frequency down on its value in a vacuum. Furthermore, the point of load on the cantilever is found to be extremely important, since a small variation in the load point can lead to a dramatic variation in the spring constant. Theoretical results that account for this variation, which, it is believed will be of great practical value to the users of the AFM, are given. © 1995 American Institute of Physics.
954 citations
TL;DR: The IBM/TENN/TULANE/LLNL/LBL Beamline 8.0 as discussed by the authors was used for graphite and titanium oxides spectroscopy, and the dispersive features in K emission spectra of graphite excited near threshold were observed.
Abstract: The IBM/TENN/TULANE/LLNL/LBL Beamline 8.0 at the advanced light source combining a 5.0 cm, 89 period undulator with a high‐throughput, high‐resolution spherical grating monochromator, provides a powerful excitation source over a spectral range of 70–1200 eV for surface physics and material science research. The beamline progress and the first experimental results obtained with a fluorescence end station on graphite and titanium oxides are presented here. The dispersive features in K emission spectra of graphite excited near threshold, and found a clear relationship between them and graphite band structure are observed. The monochromator is operated at a resolving power of roughly 2000, while the spectrometer has a resolving power of 400 for these fluorescence experiments.
325 citations
TL;DR: In this article, the authors presented a detailed investigation of the deflection properties of the V-shaped AFM cantilever, and in so doing, show that the PBA is in fact a valid and accurate approximation, provided the width and length of the parallel rectangular arms are chosen appropriately.
Abstract: Due to its simplicity, the parallel beam approximation (PBA) is commonly used in the analytical evaluation of the spring constant of V‐shaped atomic force microscope (AFM) cantilevers However, the point of contention regarding the validity of the PBA is as yet an unresolved issue, which has been exacerbated by some recent contradictory reports In this paper, we present a detailed investigation of the deflection properties of the V‐shaped AFM cantilever, and in so doing, show that the PBA is in fact a valid and accurate approximation, provided the width and length of the parallel rectangular arms are chosen appropriately As a direct consequence of this finding, we obtain exceedingly simple yet accurate formulas for the V‐shaped cantilever, which will be of value to the users of the AFM
269 citations
TL;DR: An overview of some of the technologies being used to support fiber‐optic sensor development and how they are being applied is provided.
Abstract: Fiber‐optic sensor technology has experienced tremendous growth since its early beginnings in the 1970s with early laboratory demonstrations of fiber‐optic gyros and acoustic sensors and the introduction of the first commercial intensity and spectrally based sensors. These early efforts were followed by a tremendous growth of interest in the 1980s when the number of workers in the field increased from perhaps a few hundred to thousands. The result was the introduction in the 1990s of the first mass produced fiber‐optic sensors that are being used to support navigation and medical applications. The number of fiber‐optic sensors products can be expected to grow tremendously in the years to come as rapid progress continues to be made in the related optoelectronic and communication fields. This paper provides an overview of some of the technologies being used to support fiber‐optic sensor development and how they are being applied.
203 citations
TL;DR: An overall view of the field shows it to be as an active and exciting research area, highlighting several recently introduced and novel sensing materials and configurations which provide impressive results in this field of instrumentation.
Abstract: This paper reviews recent developments in the field of current measurement which employ a wide range of optical and fiber optic techniques. Depending on the current sensing mechanisms involved and the sensing materials used, optical current sensors (OCSs) may be categorized into four main groups: (i) OCSs employing optical fiber as their sensing elements, (ii) OCSs using bulk glass to sense the current, (iii) OCSs using electro‐optic hybrid sensing devices, and (iv) OCSs using magnetic field sensing devices. The operational modes of a variety of OCSs have been grouped and discussed, and several examples given. It can be seen that as a result of an intensive and wide ranging research effort using various approaches, substantial progress in the differing aspects of the optical current sensing techniques considered, such as the sensing material used, the configurations of sensing elements introduced, and the detection schemes adapted, has been achieved during the past years. An overall view of the field shows it to be as an active and exciting research area, highlighting several recently introduced and novel sensing materials and configurations which provide impressive results in this field of instrumentation. Examples of applications for the electric power industry are discussed more extensively.
196 citations
TL;DR: In this article, the authors analyzed the possibility of using the resistive coaxial cable, Thermocoax(R) Philips, as a microwave cryofilter for single electron experiments performed in a toploading system dilution refrigerator.
Abstract: We have analyzed the possibility of using the resistive coaxial cable, Thermocoax(R) Philips as a microwave cryofilter for single electron experiments performed in a top‐loading system dilution refrigerator. The biasing and signal lines made of this cable are assumed to link a single electron device kept at the lowest temperature Td to the rf filter having a temperature Tf of several kelvin. The attenuation in a wide frequency range has been calculated and it turned out that a 40‐cm‐long piece of this cable with an outer diameter of 0.5 mm could drastically reduce the effect of noise from the 50 Ω source anchored at Tf (below 25 K), making its effect comparable with the effect of the thermal fluctuations in the device for Td≊40 mK. The calculated attenuation is in reasonable agreement with the data measured at frequencies up to 18 GHz.
193 citations
TL;DR: In this paper, the OMEGA laser system, a 30kJ, 351nm, 60-beam direct-drive laser-fusion system, is described along with the status of its construction and the plans for system activation.
Abstract: The upgrade to the OMEGA laser system, a 30‐kJ, 351‐nm, 60‐beam direct‐drive laser‐fusion system is reported here. The system configuration is presented along with the status of its construction and the plans for system activation. The system utilizes rod and disk amplifiers and frequency tripling to produce UV pulses which are smoothed using phase conversion and smoothing by spectral dispersion. Dual driver lines will feed the propagation of two co‐axial beams, which have different pulse widths and occupy different portions of the laser aperture. The laser system will be completed in November 1994 and the target area in March 1995.
192 citations
TL;DR: In this article, a large optical-aperture membrane diamond anvil cell designed for infrared spectroscopy is described, and other possibilities concerning x-ray diffraction analyses with the cells are mentioned.
Abstract: A large optical‐aperture membrane diamond anvil cell designed for infrared spectroscopy is described. The cell offers definite advantages compared to existing systems. Other possibilities concerning x‐ray diffraction analyses with the cells are mentioned.
183 citations
TL;DR: In this paper, the authors used cavity ring down (CRD) absorption spectroscopy in the near UV part of the spectrum for trace gas detection of small molecules and demonstrated that CRD holds great promise for sensitive (sub)‐ppb] and fast (kHz) detection of many small molecules.
Abstract: Trace gas detection of small molecules has been performed with cavity ring down (CRD) absorption spectroscopy in the near UV part of the spectrum. The absolute concentration of the OH radical present in trace amounts in heated plain air due to thermal dissociation of H2O has been calibrated as a function of temperature in the 720–1125 °C range. Detection of NH3 at the 10 ppb level is demonstrated in calibrated NH3/air flows. Detection of the background Hg concentration in plain air is performed with a current detection limit below 1 ppt. The effect of the laser linewidth in relation to the width of the absorption line is discussed in detail. Basic considerations regarding the use of CRD for trace gas detection are given and it is concluded that CRD spectroscopy holds great promise for sensitive [(sub)‐ppb] and fast (kHz) detection of many small molecules.
TL;DR: In this article, a thermal wave resonant cavity was constructed using a thin aluminum foil wall as the intensity-modulated-laser-beam induced oscillator source opposite a pyroelectric polyvilidene fluoride wall acting as a signal transducer and cavity standing-wave-equivalent generator.
Abstract: A thermal‐wave resonant cavity was constructed using a thin aluminum foil wall as the intensity‐modulated‐laser‐beam induced oscillator source opposite a pyroelectric polyvilidene fluoride wall acting as a signal transducer and cavity standing‐wave‐equivalent generator. It was shown that scanning the frequency of oscillation produces the fundamental and higher overtone resonant extrema albeit with increasingly attenuated amplitude—a characteristic of thermal‐wave behavior. Experimentally, scanning the cavity length produced a sharp lock‐in in‐phase resonance with simple linewidth dependencies on oscillation (chopping) frequency and intracavity gas thermal diffusivity. The thermal diffusivity of air at 294 K was measured with three significant figure accuracy: 0.211±0.004 cm2/s. The novel resonator can be used as a high‐resolution thermophysical property sensor of gaseous ambients.
TL;DR: In this article, a modular system of techniques and software has been developed for the calibration and correction of intensity linearity, uniformity of response, spatial distortion, and image plate decay.
Abstract: A modular system of techniques and software has been developed for the calibration and correction of intensity linearity, uniformity of response, spatial distortion, and image plate decay. With calibration the Molecular DynamicsTM Imaging Plate scanner system has been shown to give comparable results to the MarResearchTM scanner. The ESRF x‐ray image intensifier/charge‐coupled device detectors inherently cause large spatial and uniformity of response distortions, and successful data analysis depends on calibration and correction. Results of synchrotron radiation experiments are presented.
TL;DR: In this article, the authors describe a living anionic polymerization performed under inert atmosphere and the components of the setup are described in detail, as well as Purification procedures for glassware and chemicals for specific polymerizations are given.
Abstract: ‘‘Living’’ anionic polymerization offers a readily feasible preparation of very well‐controlled homo‐ or copolymers in a wide range of molar masses and chemical structures. Such samples are vital in experimental polymer physics and the technique presented here offers self‐sufficiency with such samples. The technique of anionic polymerization performed under inert atmosphere is presented here. The components of the setup are described in detail. Purification procedures for glassware and chemicals for specific polymerizations are given. Illustrative examples and results are presented.
TL;DR: In this paper, a class of highly sensitive sensors are discussed that are based on commercially available microcantilevers, such as those used in atomic force microscopy, when coated with a sensitizing overlayer.
Abstract: The advent of inexpensive, mass‐produced microcantilevers promises to bring about a revolution in the field of chemical and physical sensor design. In this paper, a novel class of highly sensitive sensors are discussed that are based on commercially available microcantilevers, such as those used in atomic force microscopy. When coated with a sensitizing overlayer, these microcantilevers show significant changes in two independent analyte‐induced signals, resonance frequency and static bending, as the result of exposure to various chemical and physical phenomena. Resonance frequency shift has the particular advantage of being relatively insensitive to interference from external factors such as thermal drift. Examples of micromechanical sensors based on this approach that are capable of detecting mercury vapor (with a sensitivity of 1.25 Hz/pg and linear correlation of 0.998), relative humidity (55 Hz/%R.H., correlation=0.999), or optical irradiation (10 Hz/nJ response) are discussed in detail, along with the effects of coatings on sensitivity, linearity, and reversibility of response. Further, extension of this tremendously flexible concept into a universal detection paradigm for chemical and physical phenomena is examined.
TL;DR: In this article, the hydrodynamic coupling between tip and sample is employed to measure and control the distance between microelectrode and sample in scanning electrochemical microscopy, and it is shown that amplitudes of up to 5 μm can be obtained in an aqueous environment and amplitudes below 1 nm can be detected with phase sensitive amplifiers.
Abstract: The distance between microelectrode and sample is a crucial parameter in scanning electrochemical microscopy. Here we report on a technique where the hydrodynamic coupling between tip and sample is employed to measure and control this distance. We built an apparatus, where a microelectrode is vibrated laterally and the damping of the amplitude upon approach to the surface is measured optically. We show that amplitudes of up to 5 μm are easily obtained in an aqueous environment and that amplitudes below 1 nm can be detected with phase sensitive amplifiers. We measured the different vibration modes of the electrodes and identified the ones best suited for distance measurements. On hard surfaces we found the characteristic decay length of the coupling to be less than 1 μm and, within our measured range, independent of frequency and amplitude of the vibration. Measurements on an elastic surface of known spring constant revealed that the vibrating electrode exerts a repulsive normal force on the sample which m...
TL;DR: In this paper, the performance of grating and crystal monochromators is compared in the 1-2 keV photon energy range. And the performance data of a plane grating focusing condition was presented.
Abstract: During the last 10 years various types of soft x‐ray monochromators have been developed, which are optically based on the plane grating focusing condition introduced in 1980. These instruments as well as those using the original 1980 optical configuration are reviewed and compared to the other type of high performance soft x‐ray grating monochromator, the Rowland circle based spherical grating monochromator (SGM). Performance data of a plane grating monochromator (HE‐PGM‐3), which was recently commissioned at BESSY and which offers a broad spectral range (40–2000 eV) and very high spectral resolution (up to E/ΔE∼10 000) are given in more detail. The performance of grating and crystal monochromators is compared in the 1–2 keV photon energy range.
TL;DR: In this paper, the amplitude method was used to measure the thermal conductivity and diffusivity of free standing silicon nitride (Si•N) films of 0.6 and 1.4 μm in thickness.
Abstract: The thermal conductivity and diffusivity of free‐standing silicon nitride (Si‐N) films of 0.6 and 1.4 μm in thickness are measured. A new experimental technique, the amplitude method, is proposed and applied to measurement of the thin‐film thermal diffusivity. The thermal diffusivity is determined by three independent experimental approaches: the phase‐shift method, the amplitude method, and the heat‐pulse method. Good agreement among the measured thermal diffusivities obtained by the three methods indicates the validity of the amplitude method. High‐resolution electron microscopy studies show a large quantity of voids in the 1.4 μm Si‐N films. In contrast, very few voids are found in the 0.6 μm films. This difference may be responsible for the measured lower conductivity of the 1.4 μm Si‐N films as compared to the 0.6 μm thin films.
TL;DR: In this article, three designs of thermocouple cantilever probes and the thermal images obtained by each of them are presented, and experiments show that the dominant mechanism for sample-probe heat transfer is gas conduction.
Abstract: Thermocouple cantilever probes are used in the atomic force microscope (AFM) to simultaneously obtain thermal and topographical images of surfaces with submicrometer scale spatial resolution. Three designs of thermocouple AFM probes and the thermal images obtained by each of them are presented here. Experiments show that the dominant mechanism for sample‐probe heat transfer is gas conduction. If probes are not properly designed, this could lead to image distortion and loss of temperature and spatial resolution. The steady state probe behavior is dominated by the gas thermal conductivity whereas the transient effects are dominated by the thermal mass of the probe. Thermal images of single transistors show their thermal characteristics under different biasing conditions. In addition, hot spots created by short‐circuit defects within a transistor can be located by this technique. Efforts are underway to improve the spatial resolution from 0.4 to 0.05 μm by careful probe design. The results suggest that this ...
TL;DR: In this article, the authors presented the optical layout and the expected performance of the new high-flux SAXS beamline at ELETTRA, which operates with a SAX s resolution between 10 and at least 1000 A in d spacing at 8 keV and has been optimized with respect to extreme flux.
Abstract: The optical layout and the expected performance of the new high‐flux SAXS beamline at ELETTRA is presented. From the high‐power wiggler spectrum the three discrete energies 5.4, 8, and 16 keV will be selected with a double‐crystal monochromator which contains three pairs of separated asymmetrically cut plane Si(111) crystals. Downstream, the beam will be focused by a torodial mirror. The optical axis of the beamline will be horizontally 1.25 mrad off wiggler axis and the beamline will accept about 1 mrad horizontally and 0.3 mrad vertically. The beamline will operate with a SAXS resolution between 10 and at least 1000 A in d spacing at 8 keV and has been optimized with respect to extreme flux. A flux at the sample in the order of 1013 ph/s is expected for 8 keV photons (2 GeV, 400 mA). It will be possible to perform wide angle scattering measurements in the range of 3.5 and 7 A d spacing at 8 keV simultaneously.
TL;DR: A phase contrast x-ray computed tomography (PCX-CT) was proposed in this article, which combines a phase contrast imaging technique with X-ray CT to provide sectional images of organic specimens that would produce absorption-contrast x−ray CT images with little contrast.
Abstract: A novel three‐dimensional x‐ray imaging method has been developed by combining a phase‐contrast x‐ray imaging technique with x‐ray computed tomography. This phase‐contrast x‐ray computed tomography (PCX‐CT) provides sectional images of organic specimens that would produce absorption‐contrast x‐ray CT images with little contrast. Comparing PCX‐CT images of rat cerebellum and cancerous rabbit liver specimens with corresponding absorption‐contrast CT images shows that PCX‐CT is much more sensitive to the internal structure of organic specimens.
TL;DR: In this paper, the authors used the BESSY storage ring for phase contrast studies with the possibility of quick change between imaging in amplitude and phase contrast mode with the advantage of considerable higher image contrast and reduced radiation dosage compared to amplitude contrast.
Abstract: The transmission x‐ray microscope at the BESSY storage ring is being used for investigations in the fields of biology, biophysics, medicine, colloid chemistry, and soil sciences. The system has been instrumented for phase contrast studies with the possibility of quick change between imaging in amplitude and phase contrast mode. Phase contrast has the advantage of considerable higher image contrast and reduced radiation dosage compared to amplitude contrast. A cryogenic object chamber has been implemented on the x‐ray microscope. First experiments have shown that at cryogenic temperatures the structural stability of biological specimens is increased by three orders of magnitude in comparison with unfixed wet specimens at room temperature.
TL;DR: In this article, the development of capacitance tomographic imaging systems at UMIST for oil pipeline measurements is described and two ECT systems based on charge/discharge capacitance measuring circuits are described.
Abstract: UMIST is one of the establishments where process tomography techniques were first developed This paper introduces the development of capacitance tomographic imaging systems at UMIST for oil pipeline measurements The principles of electrical capacitance tomography (ECT) are briefly presented and two ECT systems based on charge/discharge capacitance measuring circuits are described These systems, a PC‐based 8‐electrode system and a Transputer‐based 12‐electrode system, have been used to visualise oil pipelines Future developments of ECT technology are discussed, including a low‐cost PC‐based ECT system, a twin‐plane ECT system which can measure the velocity profile of a pipeline flow, a multi‐frequency ECT system using ac capacitance measuring circuits and an ECT system with a rotating parallel excitation field
TL;DR: A facility for infrared microspectroscopy is under development at the NSLS of Brookhaven National Laboratory as mentioned in this paper, where the high brightness infrared light produced as synchrotron radiation makes a nearly ideal source for micro spectroscopy.
Abstract: A facility to perform infrared microspectroscopy is under development at the NSLS of Brookhaven National Laboratory. The high brightness infrared light produced as synchrotron radiation makes a nearly ideal source for microspectroscopy. High quality spectra from 10 μm sized areas can be acquired in less than 1 min. A description of the installation, microspectroscopy performance, and an example application are presented.
TL;DR: The Fourier transform spectrometer (FTS) has become an important analytical tool for these purposes as discussed by the authors, and has found great acceptance for the difficult tasks of remote sensing of the Earth from satellites, and for space exploration by probes to other planets.
Abstract: Infrared spectroscopy has many applications, and the Fourier transform spectrometer (FTS) has become an important analytical tool for these purposes. In addition to its use in benign laboratory environments, the FTS has found great acceptance for the difficult tasks of remote sensing of the Earth from satellites, and for space exploration by probes to other planets. This paper provides an overview of the characteristics and applications of many of the spaceborne FTS systems used in the past as well as those on the drawing boards for future use. A discussion of critical design issues is included in addition. A review of Fourier transform spectroscopy principles; a brief history of FTS instrument development; and a discussion of a possible future direction are also provided. An extensive list of references is contained as well.
TL;DR: In this paper, two slightly different high-speed framing cameras for use on NOVA and OMEGA upgrade were constructed based on the gating of a microchannel plate, with one detector having a pore length to diameter ratio half that of the other.
Abstract: We have constructed two slightly different high‐speed framing cameras for use on NOVA and the OMEGA Upgrade. Both units are based on the gating of a microchannel plate, with one detector having a pore length to diameter ratio half that of the other. We will discuss the factors limiting the temporal resolution of each detector and will compare the results of modeling with gate width measurements taken using a short‐pulse laser. We will also compare time‐resolved x‐ray images recorded using one of these devices with data from an older (∼90 ps resolution) detector.
TL;DR: In this article, a survey of the factors governing the performance and operation of high temperature subsupersonic metal atom beam sources is presented, with a focus on resistive heater materials and ceramics.
Abstract: This paper presents a survey of the factors governing the performance and operation of high temperature subsupersonic metal atom beam sources. After an initial statement of the requirements placed on such sources a section is presented which considers the factors determining atomic beam intensities and profiles. The section which considers the materials used in source construction discusses the choice of crucible material, and in so doing presents a table of the most suitable materials, hazard assessments, and other information for all those elements which can be vaporized. Two further parts of this section are devoted to resistive heater materials and ceramics. The review of the sources is divided between resistively heated sources, sources heated by electron bombardment, and inductively heated sources. Finally there is a section which briefly discusses the monitoring of source performance.
TL;DR: The ALS beamline 7.0 as discussed by the authors is an integrated system for delivering radiation from a 5 cm period undulator to spectroscopy and microscopy experiments across the range of photon energies from 60 to 1200 eV.
Abstract: The performance of ALS beamline 7.0 is described. This is an integrated system for delivering radiation from a 5 cm period undulator to spectroscopy and microscopy experiments across the range of photon energies from 60 to 1200 eV. The beamline is engineered to deliver the highest possible flux, with negligible deformation of the optic surfaces due to heating. Two experiment stations are served with rapid interchangeability. The measured operational parameters, the resolution and flux delivered, and the refocus of the light into a small spot at the experiment are all discussed.
TL;DR: In this article, a large-aperture x-ray TV-type detector was developed for diffraction with synchrotron radiation, which consists of a beryllium-windowed xray image intensifier, an optical lens, a charge coupled device (CCD) image sensor, and data acquisition system.
Abstract: A large‐aperture (150 mm and 230 mm in diameter) x‐ray TV‐type detector has been developed for x‐ray diffraction with synchrotron radiation. The detector consists of a beryllium‐windowed x‐ray image intensifier, an optical lens, a charge coupled device (CCD) image sensor, and data acquisition system. The spatial resolution is 270 μm(FWHM), and the dynamic range is 6000:1. The noise level is quantum limited. The nonuniformity of response and image distortion is corrected by software. When a TV‐rate (NTSC‐mode) CCD is used as an image sensor, time‐resolved measurements with a rate of 30 frame/s can be achieved with its noise quantum limited.
TL;DR: In this paper, a Fourier transform infrared micro-spectrometer was interfaced with the National Synchrotron Light Source (NSLSTM) to provide high-quality IR spectra for probe diameters at the diffraction limit.
Abstract: When a Fourier transform infrared microspectrometer was first interfaced with the National Synchrotron Light Source in September 1993, there was an instant realization that the performance at the diffraction limit had increased 40–100 times. The synchrotron source transformed the IR microspectrometer into a true IR microprobe, providing high‐quality IR spectra for probe diameters at the diffraction limit. The combination of IR microspectroscopy and synchrotron radiation provides a powerful new tool for molecular spectroscopy. The ability to perform IR microspectroscopy with synchrotron radiation is still under development at Brookhaven National Laboratory, but several initial studies have been completed that demonstrate the broad‐ranging applications of this technology and its potential for materials characterization.