The measurement of the energy spectrum of cosmic ray helium nuclei from 70 GeV to 80 TeV using 4.5 years of data recorded by the Dark Matter Particle Explorer (DAMPE) is reported in this work. A ...hardening of the spectrum is observed at an energy of about 1.3 TeV, similar to previous observations. In addition, a spectral softening at about 34 TeV is revealed for the first time with large statistics and well controlled systematic uncertainties, with an overall significance of 4.3σ. The DAMPE spectral measurements of both cosmic protons and helium nuclei suggest a particle charge dependent softening energy, although with current uncertainties a dependence on the number of nucleons cannot be ruled out.
CRYSTAL EYE: A new X and gamma ray all-sky-monitor for space missions Barbato, F.C.T.; Abba, A.; Anastasio, A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
April 2023, 2023-04-00, Letnik:
1049
Journal Article
Recenzirano
The CRYSTAL EYE detector is proposed as a space-based X and gamma ray all-sky monitor to be active from 10 keV up to 30 MeV. In its full scale configuration, it consists in a 40 cm diameter ...hemisphere, made by 112 pixels, with an overall weight lower than 50 kg, wide Field Of View (FOV, about 6 sr), full sky coverage and very large effective area (about 6 times higher than Fermi-GBM at 1 MeV) in the energy range of interest.
Each pixel consists of two layers of scintillating LYSO crystals, read out by arrays of Silicon PhotoMultipliers (SiPMs), equipped with a segmented anticoincidence detector for charged Cosmic Ray (CR) identification and hard X-ray detection.
The primary scientific goals include the observation of transient X and gamma flashes from Gamma Ray Bursts (GRBs), Gravitational Wave (GW) follow up, Supernovae (SN) explosions, etc. and stable gamma-ray source observation in the MeV energy range. The pioneering design optimizes these observations in terms of localization of the source and timing. By using specific triggers for charged particles, solar flares and space weather phenomena could also be studied.
A pathfinder mission is foreseen onboard of the Space Rider vehicle run by European Space Agency (ESA), allowing technology tests, qualification and both deep space and Earth observation during the mission. We here present the CRYSTAL EYE technology.
This paper describes a method for the measurement of gain and linearity of photomultipliers (PMTs). Gain and linearity are two fundamental parameters to use properly a PMT in several physics ...experiments. In the developed system light is laser generated and adressed to the PMT through a set of optical fibers. The data acquisition system consists in a commercial 16 channel digitizer coupled to a custom front-end board. With the chosen digitizer the system is scalable to test up to 16 PMTs, with the aid of a light distribution system and a multi-channel version of the front-end board. Data analysis is performed by a custom acquisition software. A 1.5" Hamamatsu PMT is used to validate the system.
Status of the plastic scintillator detector for the HERD experiment Alemanno, F.; Altomare, C.; Barbato, F.C.T. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
June 2023, 2023-06-00, Letnik:
1051
Journal Article
Recenzirano
Future satellite experiments for cosmic-ray and gamma-ray detection will employ plastic scintillators to discriminate gamma-rays from charged particles and to identify nuclei up to Iron. The High ...Energy Cosmic Radiation Detector (HERD) facility will be one of those new experiments and it will be installed onboard the Chinese Tiangong Space Station (TSS). The main goal of the HERD experiment is to detect charged cosmic-rays up to PeVand gamma-rays up to hundred GeVs. The plastic scintillator detector (PSD) surrounds the inner detectors on five sides. For energies above a few GeVs a high detector segmentation is required in order to avoid the back-splash effect, due to the interaction between high energy particles and the innermost calorimeter. Each PSD basic element (bar or tile) is coupled to several Silicon Photomultipliers (SiPMs) for the detection of scintillation light. In 2021 we have performed a beam test campaign to test all the subdetectors of the HERD experiment at CERN PS and SPS. We tested two different PSD prototypes, one with a long bar geometry and the other with a squared tile geometry. In both prototypes two scintillating materials (BC-404 and BC-408) were used. Both the prototypes were equipped with SiPMs of two different sizes (MPPC S14160-3050 and S14160-1315) and they were read-out by the CAEN Citiroc-based board DT5550 W. In this work we will describe the PSD design along with the beam test results.
The Pierre Auger Observatory is undergoing a major upgrade named AugerPrime with the primary aim to add sensitivity to the mass-composition discrimination of ultrahigh-energy cosmic rays. Two ...different photomultipliers will be added to each water-Cherenkov station of the surface detector of Observatory. To achieve the scientific goals of AugerPrime these photomultipliers have to ensure a linear response to input-light in a wide range. This paper describes a system developed for the validation of AugerPrime-photomultipliers.
The 2-inches VSiPMT industrial prototypes Barbato, F.C.T.; Barbarino, G.; Rosa, G. De ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2020, Letnik:
958
Journal Article
Recenzirano
Photon detection is a key factor to study many physical processes in several areas of fundamental physics research. Focusing the attention on photodetectors for particle astrophysics, we understand ...that we are very close to new discoveries and new results. In order to push the progress in the study of very high-energy or extremely rare phenomena (e.g. dark matter, proton decay, neutrinos from astrophysical sources) the current and future experiments require additional improvements in linearity, gain, quantum efficiency and single photon counting capability. To meet the requirements of these classes of experiments, we propose a new design for a modern hybrid photodetector: the VSiPMT (Vacuum Silicon PhotoMultiplier Tube).
The idea is to replace the classical dynode chain of a PMT with a SiPM, which therefore acts as a single stage Geiger electron detector and amplifier, without statistical fluctuations. The aim is to match the large sensitive area of a photocathode with the performances of the SiPM technology. The previous VSiPMT prototypes already showed many attractive features such as low power consumption, very large dynamic range, excellent photon counting capability and low voltage driven gain.
We now present the results of the full characterization of the latest and largest version achieved up to now, a 2-inches VSiPMT manufactured by Hamamatsu.
•The VSiPMT is a new high gain photodetector with very good photon counting capability.•Inches prototypes have been realized in collaboration with Hamamatsu.•The prototypes have been tested with very good results.•The prototypes will be tested in a little experiment to compare their answer with both a matrix of SiPMs both a PMT.
The VSiPMT (Vacuum Silicon PhotoMultiplier Tube) is an original design for an innovative light detector we proposed with the aim to create new scientific instrumentation for future missions of ...exploration and observation of the universe. The idea behind this device is to replace the classical dynode chain of a photomultiplier tube with a silicon photomultiplier, the latter acting as an electron detector and amplifier.
In this way we obtain a large area photodetector with an excellent photon counting, proper of the SiPMs, but with the dark noise of only one SiPM (1-inch is equivalent to ∼ 54 SiPM 3 × 3 mm2).
From this point of view, the VSiPMT offers very attractive features and unprecedented performance in large area detection, such as: negligible power consumption, excellent SPE resolution, easy low-voltage-based stabilization and very good time performance.
Hamamatsu realized for our group a 1-inch prototype. The results of the full characterization of the device are presented in this work.
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