Search results for "Detector"
showing 10 items of 3491 documents
Photoresponse of graphene ruthenium-complex heterostructures
2015
The aim of this study is to understand the photoresponse of a Ruthenium-complex/graphene heterostructure. Early work demonstrated that light detection by graphene field effect devices was enhanced by dropcasting Ruthenium Complex molecules. Here we proposed to fabricate a new class of devices where the Ruthenium-complex molecules are embedded between two layer of CVD monolayer graphene.
Positron production using a 9 MeV electron linac for the GBAR experiment
2020
For the GBAR (Gravitational Behaviour of Antihydrogen at Rest) experiment at CERN's Antiproton Decelerator (AD) facility we have constructed a source of slow positrons, which uses a low-energy electron linear accelerator (linac). The driver linac produces electrons of 9 MeV kinetic energy that create positrons from bremsstrahlung-induced pair production. Staying below 10 MeV ensures no persistent radioactive activation in the target zone and that the radiation level outside the biological shield is safe for public access. An annealed tungsten-mesh assembly placed directly behind the target acts as a positron moderator. The system produces $5\times10^7$ slow positrons per second, a performan…
High-Resolution 3-D CZT Drift Strip Detectors for Prompt Gamma Ray and Neutron Detection in BNCT
2021
Spectroscopic imagers based on high-Z and wide-bandgap compound semiconductor detectors are widely proposed for the detection of prompt gamma rays in boron neutron capture therapy (BNCT). BNCT is a therapy based on the neutron capture reaction 10B (n,α)7Li. To perform a real-time monitoring of the spatial distribution of 10B during the treatments, the detection of the prompt gamma rays (478 keV), produced by the 7Li recoil nuclei, can be helpful. In this work, we presented the potentialities of new high-resolution CZT drift strip detectors, recently developed by our group, for BNCT measurements. The detectors, exploiting the analysis of the collected-induced charge pulses from anodes, catho…
Charged jet cross sections and properties in proton-proton collisions at $\sqrt{s}=7$ TeV
2015
The differential charged jet cross sections, jet fragmentation distributions, and jet shapes are measured in minimum bias proton-proton collisions at centre-of-mass energy $\sqrt{s}=7$ TeV using the ALICE detector at the LHC. Jets are reconstructed from charged particle momenta in the mid-rapidity region using the sequential recombination $k_{\rm T}$ and anti-$k_{\rm T}$ as well as the SISCone jet finding algorithms with several resolution parameters in the range $R=0.2$ to $0.6$. Differential jet production cross sections measured with the three jet finders are in agreement in the transverse momentum ($p_{\rm T}$) interval $20<p_{\rm T}^{\rm jet,ch}<100$ GeV/$c$. They are also consistent w…
Deep-learning based reconstruction of the shower maximum X max using the water-Cherenkov detectors of the Pierre Auger Observatory
2021
The atmospheric depth of the air shower maximum $X_{\mathrm{max}}$ is an observable commonly used for the determination of the nuclear mass composition of ultra-high energy cosmic rays. Direct measurements of $X_{\mathrm{max}}$ are performed using observations of the longitudinal shower development with fluorescence telescopes. At the same time, several methods have been proposed for an indirect estimation of $X_{\mathrm{max}}$ from the characteristics of the shower particles registered with surface detector arrays. In this paper, we present a deep neural network (DNN) for the estimation of $X_{\mathrm{max}}$. The reconstruction relies on the signals induced by shower particles in the groun…
Responsivity measurements of SiC photodiodes
2014
We investigated the technical features of three novel classes of 4H-SiC vertical Schottky UV photodiodes (henceforth, named SiC8, SiC10, SiC20) employing Ni2Si interdigitated strips whose pitch size is 8, 10 and 20 µm respectively [1] and based on the pinch-off surface effect.
Development of high resolution and efficiency detectors based on Silicon Photomultipliers (SIPMS) and continuous crystals for medical physics applica…
2017
El trabajo presentado en esta tesis introduce y evalúa dos aspectos novedosos en los detectores de rayos gamma para imagen médica: el uso de fotomultiplicadores de silicio (SiPMs, en inglés) acoplados a cristales centelleadores continuos. Tradicionalmente, los tubos fotomultiplicadores (PMTs, en inglés) acoplados a cristales centelleadores han jugado un papel dominante en la detección de rayos gamma. En los últimos años ha aparecido un nuevo tipo de fotodetector de estado sólido, el SiPM, como opción para sustituir a los PMTs en ciertas aplicaciones. Los SiPMs tienen una ganancia y una eficiencia cuántica altas, un voltaje de operación bajo y unas propiedades temporales excelentes. Además, …
Development of 2D & 3D cadmium–zinc–telluride spectroscopic imagers for X-ray and gamma ray applications
2021
A concept for the extraction of the most refractory elements at CERN-ISOLDE as carbonyl complex ions
2021
The European physical journal / A 58(5), 94 (2022). doi:10.1140/epja/s10050-022-00739-1
Characterization of a CZT focal plane small prototype for hard X-ray telescope
2005
The promise of good energy and spatial resolution coupled with high efficiency and room temperature operation has fuelled a large international effort to develop cadmium zinc telluride (CZT) for hard X-ray applications. We are involved on the development of a hard X-ray telescope based on multilayer optics and focal plane detector operative in the 10-80 keV energy range. This telescope requires a high efficiency focal plane providing both fine spatial resolution and spectroscopy with a compact and robust design. This paper reports preliminary results on the characterization both in spectroscopic and spatial response of two small pixellated CZT detectors (10times10times1 mm3 and 10times10tim…