Search results for "silicon"
showing 10 items of 1391 documents
Operation of silicon photomultipliers as photosensors of liquid xenon detectors
2016
Silicon Photomultipliers as photosensors for liquid xenon detectors are an attractive alternative to photomultiplier tubes: liquid xenon detectors employed in low background experiments or compact Compton cameras can take advantage of the small sensor mass and dimensions, the larger light collection coming from a more packed tiling of the readout plane, and possibly a smaller cost per area. We investigate the operation in liquid xenon of samples developed by Ketek GmbH. To provide sensitivity to the liquid xenon scintillation light wavelength, 178 nm, the inactive entrance layer of the device has been thinned. The operation of such devices at temperatures as low as −100°C has been verified,…
Wearable, Fiber-less, Multi-Channel System for Continuous Wave Functional Near Infrared Spectroscopy Based on Silicon Photomultipliers Detectors and …
2019
Development and in-vivo validation of a Continuous Wave (CW) functional Near Infrared Spectroscopy (fNIRS) system is presented. The system is wearable, fiber-less, multi-channel (16×16, 256 channels) and expandable and it relies on silicon photomultipliers (SiPMs) for light detection. SiPMs are inexpensive, low voltage and resilient semiconductor light detectors, whose performances are analogous to photomultiplier tubes (PMTs). The advantage of SiPMs with respect to PMTs is that they allow direct contact with the scalp and avoidance of optical fibers. In fact, the coupling of SiPMs and light emitting diodes (LEDs) allows the transfer of the analog signals to and from the scalp through thin …
Post UV irradiation annealing of E’ centers in silica controlled by H2 diffusion
2004
Abstract We investigate the isothermal annealing of E′ centers generated by UV photons (266 nm) of a pulsed Nd:YAG laser in two natural silica types differing for their OH content. Electron spin resonance and absorption spectra recorded at room temperature at different delays from the laser exposure evidenced a partial reduction of E′ centers, more pronounced in the wet silica. These post irradiation kinetics complete within 10 5 s, regardless the silica type, and they are consistent with a diffusion limited reaction between the E′ centers and the molecular hydrogen H 2 . Analysis of our data is done by theoretical fits using the Waite's equation and compared with the H 2 diffusion paramete…
Photoabsorption and MXCD in Photoemission Microscopy for Characterization of Advanced Materials
1999
We used imaging spectromicroscopy to characterise micro-patterned thin films of magnetic materials like FeNi alloys on Silicon. To investigate devices built from complex materials we applied element-sensitive photoelectron emission microscopy (PEEM). Information about the chemical composition of the imaged sample can be obtained by PEEM via tuning the photon energy to X-ray absorption edges. One aim of our work was to observe oxygen related defects and changes in the composition effecting the physical properties of the materials. The use of circularly polarised photons allows us to image magnetic domains by making use of the magnetic circular dichroism (MXCD).
The experimental setup of the Interaction in Crystals for Emission of RADiation collaboration at Mainzer Mikrotron: Design, commissioning, and tests
2015
Silicon/germanium flat/bent crystals are thin devices able to efficiently deflect charged particle GeV-energy beams up to a few hundreds of μrad; moreover, high intensity photons can be efficiently produced in the so-called Multi-Volume Reflection (MVR) and Multiple Volume Reflections in One Crystal (MVROC) conditions. In the last years, the research interest in this field has moved to the dynamic studies of light negative leptons in the low energy range: the possibility to deflect negative particles and to produce high intensity γ sources via the coherent interactions with crystals in the sub-GeV energy range has been proved by the ICE-RAD (Interaction in Crystals for Emission of RADiation…
Study of the material of the ATLAS inner detector for Run 2 of the LHC
2017
The ATLAS inner detector comprises three different sub-detectors: the pixel detector, the silicon strip tracker, and the transition-radiation drift-tube tracker. The Insertable B-Layer, a new innermost pixel layer, was installed during the shutdown period in 2014, together with modifications to the layout of the cables and support structures of the existing pixel detector. The material in the inner detector is studied with several methods, using a low-luminosity root s = 13 TeV pp collision sample corresponding to around 2.0 nb(-1) collected in 2015 with the ATLAS experiment at the LHC. In this paper, the material within the innermost barrel region is studied using reconstructed hadronic in…
Innovative remotely-controlled bending device for thin silicon and germanium crystals
2020
Steering of negatively charged particle beams below 1 GeV has demonstrated to be possible with thin bent silicon and germanium crystals. A newly designed mechanical holder was used for bending crystals, since it allows a remotely-controlled adjustment of crystal bending and compensation of unwanted torsion. Bent crystals were installed and tested at the MAMI Mainz MIcrotron to achieve steering of 0.855-GeV electrons at different bending radii. We report the description and characterization of the innovative bending device developed at INFN Laboratori Nazionali di Legnaro (LNL).
TRITIUM - A Real-Time Tritium Monitor System for Water Quality Surveillance
2018
In this work the development results of the TRITIUM project is presented. The main objective of the project is the construction of a near real-time monitor for low activity tritium in water, aimed at in-situ surveillance and radiological protection of river water in the vicinity of nuclear power plants. The European Council Directive 2013/51/Euratom requires that the maximum level of tritium in water for human consumption to be lower than 100 Bq/L. Tritium levels in the cooling water of nuclear power plants in normal operation are much higher than the levels caused by the natural and cosmogenic components, and may easily surmount the limit required by the Directive. The current liquid-scint…
The ATLAS Inner Detector commissioning and calibration
2010
The ATLAS Inner Detector is a composite tracking system consisting of silicon pixels, silicon strips and straw tubes in a 2 T magnetic field. Its installation was completed in August 2008 and the detector took part in data-taking with single LHC beams and cosmic rays. The initial detector operation, hardware commissioning and insitu calibrations are described. Tracking performance has been measured with 7.6 million cosmic-ray events, collected using a tracking trigger and reconstructed with modular pattern-recognition and fitting software. The intrinsic hit efficiency and tracking trigger efficiencies are close to 100%. Lorentz angle measurements for both electrons and holes, specific energ…
Design, upgrade and characterization of the silicon photomultiplier front-end for the AMIGA detector at the Pierre Auger Observatory
2021
The successful installation, commissioning, and operation of the Pierre Auger Observatory would not have been possible without the strong commitment and effort from the technical and administrative staff in Malargue. We are very grateful to the following agencies and organizations for financial support: Argentina -Comision Nacional de Energia Atomica; Agencia Nacional de Promocion Cientifica y Tecnologica (ANPCyT); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET); Gobierno de la Provincia de Mendoza; Municipalidad de Malargue; NDM Holdings and Valle Las Lenas; in gratitude for their continuing cooperation over land access; Australia -the Australian Research Council; Braz…