Detection of neutrons is becoming of the utmost importance, especially in the studies of radioactive waste and in homeland security applications. The crisis of
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He availability has required the ...development of innovative techniques. One solution is to develop light gas detectors for neutron counting to be used as portals for ports and airports. The neutron is converted on the Boron-coated cathode, releasing a charged particle, whose passage can be identified by the gas detector. While several technologies have been deployed in the past, the project μRANIA-V (μRwell Advanced Neutron Identification Apparatus) aims to detect thermal neutrons by means of the μRwell technology, an innovative gas detector. The goal is to produce tiles to operate as portals in homeland security or for radioactive waste management. The technological transfer towards the industry has started, thus the production can be cost-effective also owing to a construction process relatively easier compared to similar apparatus. By reading directly the signals from the amplification stage, the neutrons can be counted with simplified electronics further reducing the total cost. In this paper, the project will be described, with details on the μRwell technology and on the neutron counting, on the test beam performed, and on the future plans.
Gas detector development is one of the pillars of the research in fundamental physics. Since several years, a new concept of detectors, called Micro Pattern Gas Detector (MPGD), allowed to overcome ...several problems related to other types of commonly used detectors, like drift chamber and micro strips detectors, reducing the rate of discharges and providing better radiation tolerance. Among the most used MPGDs are the Gas Electron Multipliers (GEMs). Invented by Sauli in 1997, nowadays GEMs have become an important reality for particle detectors in high energy physics. Commonly deployed as fast timing detectors and triggers, their fast response, high rate capability and high radiation hardness make them also suitable as tracking detectors. The readout scheme is one of the most important features in tracking technology. Analog readout based on the calculation of the center of gravity technique allows to overcome the limit imposed by digital pads, whose spatial resolution is limited by the pitch dimensions. However, the presence of high external magnetic fields can distort the electronic cloud and affect the performance. The development of the micro-TPC reconstruction method brings GEM detectors into a new prospective, improving significantly the spatial resolutionin presence of high magnetic fields. This innovative technique allows to reconstruct the 3-dimensional particle position, as Time Projection Chamber, but within a drift gap of a few millimeters. In these report, the charge centroid and micro-TPC methods are described in details. We discuss the results of several test beams performed with planar chambers in magnetic field. These results are one of the first developments of micro-TPC technique for GEM detectors, which allows to reach unprecedented performance in a high magnetic field of 1 T.
Le but de cette étude est d’évaluer la faisabilité de l’examen échographique et doppler de l’artère interosseuse postérieure afin d’améliorer la fiabilité du lambeau interosseux postérieur en ...préopératoire en adaptant sa technique de prélèvement qui peut être fascial ou fascio-cutané.
Dix poignets droits ont été étudiés chez 10 patients (5 hommes et 5 femmes). Il s’agissait de sujets sains volontaires, d’âge moyen 46,4 ans (36 à 58 ans).
Le repérage de l’artère interosseuse postérieure se faisait à la partie inférieure de l’avant-bras. Il était effectué une recherche de l’anastomose avec l’artère interosseuse antérieure. Puis l’artère interosseuse postérieure était suivie jusqu’à la jonction 1/3 moyen, 1/3 supérieur de l’avant-bras. Il était noté en cours d’examen la variation des flux, en fonction du niveau. Une recherche de l’artère jusqu’au réseau anastomotique dorsal du poignet était réalisée à la fin de chaque examen. Deux mesures de flux et de diamètre de l’artère étaient effectuées.
L’anastomose entre les 2 artères interosseuses a été visualisée dans 8 cas sur 10. Dans 1 cas, l’anastomose était douteuse mais il existait une augmentation du diamètre et du flux artériel. Dans 1 cas, le diamètre et le flux étaient diminués.
L’artère interosseuse postérieure est aisée à identifier en échographie doppler. Même lorsqu’elle est de petit diamètre à la partie moyenne de l’avant-bras, cette artère reste facile à identifier et à suivre par la technique de l’ascenseur. Le plus souvent, la jonction avec l’artère interosseuse antérieure est visualisable dans sa partie initiale ; ceci permet de répondre à la question de la présence de cette anastomose. Par ailleurs, nous pensons que le renforcement de l’artère (en diamètre, et en flux) et de son excellente visualisation à la partie inférieure peut être considérée comme un signe indirect de la présence de l’anastomose entre artère interosseuse antérieure et artère interosseuse postérieure. Il est ainsi possible de proposer un arbre décisionnel pour la technique de prélèvement basé sur les données échographiques.
L’échographie permet d’analyser facilement l’artère interosseuse postérieure et son anastomose avec l’artère interosseuse antérieure. Elle devrait permettre d’adapter ainsi le mode de prélèvement à l’aspect anatomique échographique. Ces résultats sur le sujet sain méritent confirmation clinique.
A new inner tracker based on a cylindrical gas electron-multiplier detector is under development to replace the current inner drift chamber of the BES III spectrometer. The BES III experiment is ...carried out at the BEPC II e
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collider in Beijing at center-of-mass energies in the tau-charm region with a design luminosity of 1.0
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cm
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. The new inner tracker consists of three cylindrical layers of triple GEM surrounding the interaction point, covering 93% of solid angle. To fulfill physics requirements, a spatial resolution of 130 μm must be achieved. Both planar and cylindrical prototypes have been built and tested. A custom ASIC using UMC 110-nm technology has been designed to provide charge and time measurements—the first prototype is in testing. Notable and innovative aspects of the new inner tracker and the performance of the detector prototypes and readout ASIC are reported here.
TRICK: A tracking ring imaging CherenKov detector Balossino, I.; Cibinetto, G.; Contalbrigo, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
April 2023, 2023-04-00, Letnik:
1049
Journal Article
Recenzirano
TRICK is a project funded by the INFN CSN5 Young grant 2020. It will use an innovative 5D technique to provide information about 3D position, time, and ID of the incoming particles. The proposed idea ...is based on the well-known technology of GEM-based TPC together with conventional Aerogel proximity focussing RICH in a single box. Both parts, TPC and RICH, will be read out simultaneously and instrumented with the same TIGER ASIC developed for the BESIII CGEM-IT detector. By combining information from both systems, the TRICK technique will improve the performance of each instrument: precise time information will help the extraction of the TPC position, while tracking will help the rings identification, by measuring the expected centre, also in a magnetic field. The TRICK-box prototype, instrumented with triple-GEM and Hamamatsu H12700 MA-PMT, aims to achieve a spatial resolution of 100 μm, time resolution below 1 ns, and 3σ separation for π/K up to 4 GeV.
This paper introduces the project and focuses on the initial studies with the prototype, the preparation of the first cosmic stand, and the next steps.
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