Search results for "SCOPE"
showing 10 items of 2420 documents
Self-Assembled System of Semiconductor and Virus Like Nanoparticles
2009
Virus like nanoparticles (VLP) are in use to be absorbed by cells to cause biological effects. To increase a local concentration of VLP, nanoparticles-carriers bringing the latter to the target cell could be employed. N-type and p-type Si semiconductor nanoparticles, to control adhesion of VLP were applied. Optical absorbance spectra and electron microscopy evidenced that VLP became connected to Si nanoparticles. Moreover, a density of the adhered VLP depended on the type of both semiconductor and VLP.
Expansion cone for the 3-inch PMTs of the KM3NeT optical modules
2013
[EN] Detection of high-energy neutrinos from distant astrophysical sources will open a new window on the Universe. The detection principle exploits the measurement of Cherenkov light emitted by charged particles resulting from neutrino interactions in the matter containing the telescope. A novel multi-PMT digital optical module (DOM) was developed to contain 31 3-inch photomultiplier tubes (PMTs). In order to maximize the detector sensitivity, each PMT will be surrounded by an expansion cone which collects photons that would otherwise miss the photocathode. Results for various angles of incidence with respect to the PMT surface indicate an increase in collection efficiency by 30% on average…
Reproducible optical fiber tips for photon scanning tunneling microscopy with very small (>5°) cone angle
1998
Sharp optical fiber tips for photon scanning tunneling microscopes (PSTMs) have been fabricated by employing a new alternative technique for etching multimode optical fibers. The tip diameter is less than 30 mm, while the cone full-angle can be as sharp as 3/spl deg/. To the knowledge of the authors, such tips are the sharpest reported up to now. Measurements, with 19 tips, of the evanescent wave decay distance produced by frustrated reflection of light on a same sample, show good reproducibility. Furthermore, the PSTM images, taken with the new tips, are very sharp and fit with images of the same sample obtained with an atomic force microscope (AFM).
Parallel Recording of Single Quantum Dot Optical Emission Using Multicore Fibers
2016
Single Indium Arsenide Quantum Dot emission spectra have been recorded using a four-core, crosstalk-free, multicore fiber placed at the collection arm of a confocal microscope. We developed two different measurement set-ups depending on the relative configuration of the excitation and collection spots. In the single-matched mode, the emission from the excited area is collected by a single core in the multicore fiber, whereas the three remaining cores capture the emission from neighboring, non-excited areas. This procedure allows for the recording of the Quantum Dot emission from carrier diffusion between sample positions separated by more than 6 μm. In the multiple-matched mode, the ex…
Observation of Light Confinement Effects with a Near-Field Optical Microscope.
1996
This Letter reports the experimental observation of light confinement effects by near-field optical microscopy. Depolarization effects giving rise to light confinement close to nanoscopic objects have been unambiguously observed in near-field optical images of subwavelength dielectric pads etched on a flat glass substrate. According to the incident polarization, this phenomenon leads to reverse contrasts in the near-field optical image of the same subwavelength objects.
A fast algorithm for muon track reconstruction and its application to the ANTARES neutrino telescope.
2011
An algorithm is presented, that provides a fast and robust reconstruction of neutrino induced upward-going muons and a discrimination of these events from downward-going atmospheric muon background in data collected by the ANTARES neutrino telescope. The algorithm consists of a hit merging and hit selection procedure followed by fitting steps for a track hypothesis and a point-like light source. It is particularly well-suited for real time applications such as online monitoring and fast triggering of optical follow-up observations for multi-messenger studies. The performance of the algorithm is evaluated with Monte Carlo simulations and various distributions are compared with that obtained …
Acoustic and optical variations during rapid downward motion episodes in the deep north-western Mediterranean Sea
2011
An Acoustic Doppler Current Profiler (ADCP) was moored at the deep-sea site of the ANTARES neutrino telescope near Toulon, France, thus providing a unique opportunity to compare high-resolution acoustic and optical observations between 70 and 170 m above the sea bed at 2475 m. The ADCP measured downward vertical currents of magnitudes up to 0.03 m s-1 in late winter and early spring 2006. In the same period, observations were made of enhanced levels of acoustic reflection, interpreted as suspended particles including zooplankton, by a factor of about 10 and of horizontal currents reaching 0.35 m s-1. These observations coincided with high light levels detected by the telescope, interpreted …
AMADEUS-The acoustic neutrino detection test system of the ANTARES deep-sea neutrino telescope
2011
The AMADEUS (ANTARES Modules for the Acoustic Detection Under the Sea) system which is described in this article aims at the investigation of techniques for acoustic detection of neutrinos in the deep sea. It is integrated into the ANTARES neutrino telescope in the Mediterranean Sea. Its acoustic sensors, installed at water depths between 2050 and 2300 m, employ piezo-electric elements for the broad-band recording of signals with frequencies ranging up to 125 kHz. The typical sensitivity of the sensors is around - 145 dB re 1 V/mu Pa (including preamplifier). Completed in May 2008, AMADEUS consists of six "acoustic clusters", each comprising six acoustic sensors that are arranged at distanc…
Calibration of the RPC charge readout in the ARGO-YBJ experiment
2012
""The charge readout of Resistive Plate Chambers (RPCs) is implemented in the ARGO-YBJ experiment to measure the charged particle density of the shower front up to 10^4\\\/m^2, enabling the study of the primary cosmic rays with energies in the ''knee'' region. As the first time for RPCs being used this way, a telescope with RPCs and scintillation detectors is setup to calibrate the number of charged particles hitting a RPC versus its charge readout. Air shower particles are taken as the calibration beam. The telescope was tested at sea level and then moved to the ARGO-YBJ site for coincident operation with the ARGO-YBJ experiment. The charge readout shows good linearity with the particle de…
Time calibration of the ANTARES neutrino telescope
2011
The ANTARES deep-sea neutrino telescope comprises a three-dimensional array of photomultipliers to detect the Cherenkov light induced by upgoing relativistic charged particles originating from neutrino interactions in the vicinity of the detector. The large scattering length of light in the deep sea facilitates an angular resolution of a few tenths of a degree for neutrino energies exceeding 10 TeV. In order to achieve this optimal performance, the time calibration procedures should ensure a relative time calibration between the photomultipliers at the level of ~1 ns. The methods developed to attain this level of precision are described.