2,663 research outputs found
Multi-detection and polarisation contrast in scannning near-field optical microscopy in reflection
A new type of NSOM probe has been developed, with a design based oÂn the probes used in Atomic Force Microscopy. The probe consists of a cantilever with at its end a conical tip. This tip has been metal-coated to provide an aperture. With the cantilevered probe, the problem of breaking of the tip due to high normal forces is solved. In operation, the tip is scanned in contact with the sample while regulating the force between the tip and the sample with a beam deflection technique, which allows to simultaneously make an optical and a topographical image of the sample. The probes are made using micromechanical techniques, which allows batch fabrication of the probes. Testing of the probes is done in a transmission NSOM set-up in which the sample is scanned while the tip and the optical path are kept fixed. Using an opaque sample with submicron holes, the new probes have been tested, resulting an optical image with a simultaneously measured topographical image
Detection of fluorescence in situ hybridization on human metaphase chromosomes by near-field scanning optical microscopy
Fluorescence in situ hybridization signals oÂn human metaphase chromosomes are detected by a near-field scanning optical microscope. This makes it possible to localize and identify several fluorescently labeled genomic DNA fragments oÂn a single chromosome with a resolution superior to traditional fluorescence microscopy. Several nucleic acid probes have been used. The hybridization signals are well resolved in the near- field fluorescence images, and the exact location of the probes can be correlated to the topography as it is afforded by the shear-force feedback
Hybrid Pixel Detector Development for the Linear Collider Vertex Tracker
In order to fully exploit the physics potential of the future high energy
e+e- linear collider, a Vertex Tracker able to provide particle track
extrapolation with very high resolution is needed. Hybrid Si pixel sensors are
an attractive technology due to their fast read-out capabilities and radiation
hardness. A novel pixel detector layout with interleaved cells has been
developed to improve the single point resolution. Results of the
characterisation of the first processed prototypes by electrostatic
measurements and charge collection studies are discussed.Comment: 5 pages, 1 figure, to appear in the Proceedings of the 9th Int.
Workshop on Vertex Detectors, Lake Michigan MI (USA), September~200
A Reversible Jump MCMC Algorithm for Particle Size Inversion in Multiangle Dynamic Light Scattering
Publication in the conference proceedings of EUSIPCO, Lisbon, Portugal, 201
Thermoelastic investigation of a quartz tuning fork used in infrared spectroscopy
International audienceThe performances of quartz tuning forks (QTF) used in infrared spectroscopy for pollutant detection are investigated. The transduction between light and QTF vibration is elucidated thanks to QTF encapsulation under vacuum. From the sensitivity enhancement which is obtained we conclude that their interaction is photo-thermoelastic rather than photo-thermoacoustic. A mapping of the local sensitivity of the QTF is obtained by scanning its faces with the excitation probe beam. The comparison between the signal mapping and the theoretical strain mapping indicates that the most efficient areas of the QTF correspond to the areas where the strain or stress are the highest
A new method for reconstructing the density distribution of matter in the disks of spiral galaxies from the rotation velocity curve in it
In this paper we propose a new method for reconstructing the surface density
of matter in flat disks of spiral galaxies. The surface density is expressed
through observational rotation velocity curves of visible matter in the disks
of spiral galaxies. The new method is not based on quadrature of special
functions. The found solution is used for processing and analysis of
observational data from several spiral galaxies. The new method can be used to
more accurately estimate the amount of dark matter in spiral galaxies.Comment: 18 pages, 6 figure
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