Abstract
The multi-TeV energy region of the cosmic-ray spectra has
been recently explored by direct detection experiments that used
calorimetric techniques to measure the energy of the cosmic
...particles. Interesting spectral features have been observed in both
all-electron and nuclei spectra. However, the interpretation of the
results is compromised by the disagreements between the data
obtained from the various experiments, that are not reconcilable
with the quoted experimental uncertainties. Understanding the
reason for the discrepancy among the measurements is of fundamental
importance in view of the forthcoming high-energy cosmic-ray
experiments planned for space, as well as for the correct
interpretation of the available results.
The purpose of this work is to investigate the possibility that a
systematic effect may derive from the non-proportionality of the
light response of inorganic crystals, typically used in high-energy
calorimetry due to their excellent energy-resolution performance.
The main reason for the non-proportionality of the crystals is that
scintillation light yield depends on ionisation density.
Experimental data obtained with ion beams were used to characterize
the light response of various scintillator materials. The obtained
luminous efficiencies were used as input of a Monte Carlo simulation
to perform a comparative study of the effect of the light-yield
non-proportionality on the detection of high-energy electromagnetic
and hadronic showers. The result of this study indicates that, if
the calorimeter response is calibrated by using the energy deposit
of minimum ionizing particles, the measured shower energy might be
affected by a significant systematic shift, at the level of few
percent, whose sign and magnitude depend specifically on the type of
scintillator material used.
We report on the structure and performance of 4H-SiC p + -n APDs fabricated in a fully planar technology. A dark current density lower than 10 nA/cm 2 at 30-V reverse bias and a breakdown voltage of ...88 V were observed. A gain as high as 10 5 was measured at 94-V reverse bias, confirming the avalanche multiplication working condition. The maximum responsivity value was measured at 270 nm, increasing from 0.06 A/W (QE = 29%) at 0-V bias to 0.10 A/W (QE of about 45%) at 30-V reverse bias.
Abstract
The measurement of cosmic-ray individual spectra provides
unique information regarding the origin and propagation of
astro-particles. Due to the limited acceptance of current space
...experiments, protons and nuclei around the “knee” region
(∼ 1 PeV) can only be observed by ground based
experiments. Thanks to an innovative design, the High Energy
cosmic-Radiation Detection (HERD) facility will allow direct
observation up to this energy region: the instrument is mainly based
on a 3D segmented, isotropic and homogeneous calorimeter which
properly measures the energy of particles coming from each direction
and it will be made of about 7500 LYSO cubic crystals. The read-out
of the scintillation light is done with two independent systems: the
first one based on wave-length shifting fibers coupled to
Intensified scientific CMOS cameras, the second one is made of two
photo-diodes with different active areas connected to a custom
front-end electronics. This photo-diode system is designed to
achieve a huge dynamic range, larger than 10
7
, while having a
small power consumption, few mW per channel. Thanks to a good
signal-to-noise ratio, the capability of a proper calibration, by
using signals of both non-interacting and showering particles, is
also guaranteed. In this paper, the current design and the
performance obtained by several tests of the photo-diode read-out
system are discussed.
Abstract
The BLEMAB European project (BLast furnace stack density Estimation through on-line Muon ABsorption measurements), evolution of the previous Mu-Blast European project, is designed to ...investigate in detail the capability of muon radiography techniques applied to the imaging of a blast furnace’s inner zone. In particular, the geometry and size of the so called “cohesive zone”, i.e. the spatial zone where the slowly downward moving material begins to soften and melt, that plays an important role in the performance of the blast furnace itself. Thanks to the high penetration power of the natural cosmic ray muon radiation, muon transmission radiography represents an appropriate non-invasive methodology for imaging large high-density structures such as blast furnaces, whose linear size can be up to a few tens of meters. A state-of-the-art muon tracking system, whose design profits from the long experience of our collaboration in this field, is currently under development and will be installed in 2022 at a blast furnace on the ArcelorMittal site in Bremen (Germany) for many months. Collected data will be exploited to monitor temporal variations of the average density distribution inside the furnace. Muon radiography results will also be compared with measurements obtained through an enhanced multipoint probe and standard blast furnace models.
The direct observation of high-energy cosmic rays, up to the PeV energy region, will increasingly rely on highly performing calorimeters, and the physics performance will be primarily determined by ...their geometrical acceptance and energy resolution. Thus, it is extremely important to optimize their geometrical design, granularity and absorption depth, with respect to the total mass of the apparatus, which is amongst the most important constraints for a space mission. CaloCube is an homogeneous calorimeter whose basic geometry is cubic and isotropic, obtained by filling the cubic volume with small cubic scintillating crystals. In this way it is possible to detect particles arriving from every direction in space, thus maximizing the acceptance. This design summarizes a three-year R&D activity, aiming to both optimize and study the full-scale performance of the calorimeter, in the perspective of a cosmic-ray space mission, and investigate a viable technical design by means of the construction of several sizable prototypes. A large scale prototype, made of a mesh of 5 × 5 × 18 CsI(Tl) crystals, has been constructed and tested on high-energy particle beams at CERN SPS accelerator. In this paper we describe the CaloCube design and present the results relative to the response of the large scale prototype to electrons.
The MIMA muon tracker, developed by the INFN Unit of Florence and the Department of Physics and Astronomy of the University of Florence, has been designed to test the application of muon radiography ...(or muography) to multidisciplinary case studies, to demonstrate its validity as an imaging tool in different fields and to develop dedicated data analysis strategies. The MIMA detector is a scaled-down version of the muon trackers developed for the “Mu-Ray” INFN R&D project and the MURAVES (MUon RAdiography of VESuvius) “Progetto Premiale”, financed by the Italian government. Thanks to its compactness, MIMA allowed the use of slightly different technical solutions with respect to the other detectors. Its construction was completed in the first half of 2017 and since then it has been used for several different measurements. In the second half of 2017 the detector was installed in the Bourbon Gallery inside Mount Echia, a hill in the center of Naples containing a complicated system of tunnels and cavities that have been dug over many centuries. The installation of the MIMA tracker was required to validate with an independent detector the results obtained in two previous measurements by the Mu-Ray tracker. After this measurement, the detector has been used in the Tuscany region, mainly for investigating two possible fields of application: geo-hydrological risk assessment and mining activity. The preliminary results of these tests and the future perspectives are shortly presented in this paper.
Current research in High Energy Cosmic Ray Physics touches on fundamental questions regarding the origin of cosmic rays, their composition, the acceleration mechanisms, and their production. ...Unambiguous measurements of the energy spectra and of the composition of cosmic rays at the “knee” region could provide some of the answers to the above questions. So far only ground based observations, which rely on sophisticated models describing high energy interactions in the Earth's atmosphere, have been possible due to the extremely low particle rates at these energies. A calorimetry based space experiment that could provide not only flux measurements but also energy spectra and particle identification, would certainly overcome some of the uncertainties of ground based experiments. Given the expected particle fluxes, a very large acceptance is needed to collect a sufficient quantity of data, in a time compatible with the duration of a space mission. This in turn, contrasts with the lightness and compactness requirements for space based experiments. We present a novel idea in calorimetry which addresses these issues whilst limiting the mass and volume of the detector. In this paper we report on a four year R&D program where we investigated materials, coatings, photo-sensors, Front End electronics, and mechanical structures with the aim of designing a high performance, high granularity calorimeter with the largest possible acceptance. Details are given of the design choices, component characterisation, and of the construction of a sizeable prototype (Calocube) which has been used in various tests with particle beams.
The direct detection of high-energy cosmic rays up to the PeV region is one of the major challenges for the next generation of space-borne cosmic-ray detectors. The physics performance will be ...primarily determined by their geometrical acceptance and energy resolution. CaloCube is a homogeneous calorimeter whose geometry allows an almost isotropic response, so as to detect particles arriving from every direction in space, thus maximizing the acceptance. A comparative study of different scintillating materials and mechanical structures has been performed by means of Monte Carlo simulation. The scintillation-Cherenkov dual read-out technique has been also considered and its benefit evaluated.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The purpose of the MU-RAY project is to develop an innovative approach to the study of volcanoes and their monitoring based on a particle physics approach. The test site is Vesuvio: one of the higher ...risk volcanoes in the world. In this context, muon radiography is an innovative method of enormous impact. This is an imaging technique which relies on the measurement, by means of a cosmic ray telescope, of the absorption in the volcano of muons with near-horizontal trajectories, produced by the interactions of cosmic rays with the atmosphere. Since 2003 this technique has been successfully used on volcanoes in Japan, providing pictures of their vertices with resolutions much better than those obtained with the traditional techniques based on gravimeters. Researchers from Naples and Florence are currently involved in the construction and testing of a prototype telescope based on the use of bars of plastic scintillator with a triangular section whose scintillation light is collected by special fibres (wave length shifters) and transported to SiPM (Silicon photomultipliers). A complete prototype telescope, consisting of three xy scintillation planes and 1m2 active area has been assembled and is now under test.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The MU-RAY detector for muon radiography of volcanoes Anastasio, A.; Ambrosino, F.; Basta, D. ...
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment,
12/2013, Volume:
732
Journal Article, Conference Proceeding
Peer reviewed
The MU-RAY detector has been designed to perform muon radiography of volcanoes. The possible use on the field introduces several constraints. First the electric power consumption must be reduced to ...the minimum, so that the detector can be solar-powered. Moreover it must be robust and transportable, for what concerns the front-end electronics and data acquisition. A 1m2 prototype has been constructed and is taking data at Mt. Vesuvius. The detector consists of modules of 32 scintillator bars with wave length shifting fibers and silicon photomultiplier read-out. A dedicated front-end electronics has been developed, based on the SPIROC ASIC. An introduction to muon radiography principles, the MU-RAY detector description and results obtained in laboratory will be presented.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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