Search results for "detector"
showing 10 items of 3491 documents
Study of the influence of temperature and precipitations on the levels of BTEX in natural waters.
2013
Assessment of seasonal changes in surface water quality is an important aspect for evaluating temporal variation of water due to natural or anthropogenic inputs of point and non-point sources. The objective of this paper was to investigate the influence of seasonal temperature fluctuations and precipitations on the levels of BTEX in natural waters. Principal component analysis (PCA) was used to evaluate the seasonal correlations of BTEX levels in water and to extract the parameters that are most important in assessing seasonal variations of water quality. This study was carried out as a part of VOCs monitoring program in natural water samples from Mediterranean coast. To carry out this proj…
Low Energy Gamma Ray Imager (LEGRI)
1995
The Low Energy Gamma Ray Imager (LEGRI) will be one of the three instruments carried by the first MINISAT mission. LEGRI aims to demonstrate the technological feasibility of a new generation of low energy gamma-ray telescopes with imaging, medium resolution spectroscopy and high continuum sensitivity in the 20-200 keV spectral region, based on HgI2 solid state detector technology.
Sensor-Oriented Passive RFID
2010
This chapter addresses the design of new UHF tag antennas for sensing applications able to host detectors and additional electronics but also to act as passive sensor itself for some modification of the target. Starting from the consideration that the tag is both a digital and an analog device, sensing data may be achieved without using microcontrollers by a simple signal processing of the tag response and of the turn-on power. The chapter is particularly focused on the monitoring of human body features even if the proposed ideas and devices, here demonstrated by simulations and experimentation, may also be applied in a variety of scenarios.
Design for a high resolution electron energy loss microscope.
2019
International audience; An electron optical column has been designed for High Resolution Electron Energy Loss Microscopy (HREELM). The column is composed of electron lenses and a beam separator that are placed between an electron source based on a laser excited cesium atom beam and a time-of-flight (ToF) spectrometer or a hemispherical analyzer (HSA). The instrument will be able to perform full field low energy electron imaging of surfaces with sub-micron spatial resolution and meV energy resolution necessary for the analysis of local vibrational spectra. Thus, noncontact, real space mapping of microscopic variations in vibrational levels will be made possible. A second imaging mode will al…
Confocal scanning microscope using a CCD camera as a pinhole-detector system
2011
We report a scheme for a detector system of confocal microscopes. In our scheme the pinhole and the large area detector are subtituted by a CCD camera. The numerical integration of the intensities acquired by the active pixels emulates the signal acquired by the detector. To demonstrate the utility of the system we efficiently performed an experiment of substractive-image confocal microscopy
Scanning microscopy with spatial sampling of the detector plane
2013
We present the implementation of a confocal scanning microscope in which the signal detection is performed through a matrix sensor, specifically, a CCD camera. This kind of detection has several advantages over the conventional detection in confocal microscopes. One of those advantages is the possibility to recover information of the sample that vanishes when the confocal image is directly acquired by the integration of light into a signal. We demonstrate the applicability of the system which allows implementing super-resolution techniques in a very easy manner.
SNEWS 2.0 : a next-generation supernova early warning system for multi-messenger astronomy
2021
The next core-collapse supernova in the Milky Way or its satellites will represent a once-in-a-generation opportunity to obtain detailed information about the explosion of a star and provide significant scientific insight for a variety of fields because of the extreme conditions found within. Supernovae in our galaxy are not only rare on a human timescale but also happen at unscheduled times, so it is crucial to be ready and use all available instruments to capture all possible information from the event. The first indication of a potential stellar explosion will be the arrival of a bright burst of neutrinos. Its observation by multiple detectors worldwide can provide an early warning for t…
Comparison of two portable solid state detectors with an improved collimation and alignment device for mammographic x-ray spectroscopy.
2006
We describe a portable system for mammographic x-ray spectroscopy, based on a 2 X 2 X 1 mm3 cadmium telluride (CdTe) solid state detector, that is greatly improved over a similar system based on a 3 X 3 X 2 mm3 cadmium zinc telluride (CZT) solid state detector evaluated in an earlier work. The CdTe system utilized new pinhole collimators and an alignment device that facilitated measurement of mammographic x-ray spectra. Mammographic x-ray spectra acquired by each system were comparable. Half value layer measurements obtained using an ion chamber agreed closely with those derived from the x-ray spectra measured by either detector. The faster electronics and other features of the CdTe detecto…
DEFINITION ET ETUDE DES PERFORMANCES D'UN DETECTEUR DE STRUCTURES CURVILINEAIRES. APPLICATION A LA STEREOSCOPIE ET LA DETECTION D'OBJETS FILAIRES
2008
The work presented in this paper falls under the domain of matching. In this context, we try to show the interest of using the curvilinear regions in order to enhance the global performance of various matching applications. A brand new detector for curvilinear regions is introduced (CRD), along with the specific curvilinear regions descriptor (CRD) required. Performance evaluations were done in two parts: First, we evaluated and compared the segmentations performances of our detector, in particular on a retina vessels segmentation application. And second, we estimated the matching performances using K. Mykolajczyk toolkit. This methodology helps obtaining intrinsic performances and comparin…
The Modular X- and Gamma-Ray Sensor (MXGS)of the ASIM Payload on the International Space Station
2019
The Modular X- and Gamma-ray Sensor (MXGS) is an imaging and spectral X- and Gamma-ray instrument mounted on the starboard side of the Columbus module on the International Space Station. Together with the Modular Multi-Spectral Imaging Assembly (MMIA) (Chanrion et al. this issue) MXGS constitutes the instruments of the Atmosphere-Space Interactions Monitor (ASIM) (Neubert et al. this issue). The main objectives of MXGS are to image and measure the spectrum of X- and γ-rays from lightning discharges, known as Terrestrial Gamma-ray Flashes (TGFs), and for MMIA to image and perform high speed photometry of Transient Luminous Events (TLEs) and lightning discharges. With these two instruments sp…