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.
We present a precise measurement of downward going albedo proton fluxes for kinetic energy above ∼70 MeV performed by the Payload for Antimatter Matter Exploration and Light‐nuclei Astrophysics ...(PAMELA) experiment at an altitude between 350 and 610 km. On the basis of a trajectory tracing simulation, the analyzed protons were classified into quasi‐trapped, concentrating in the magnetic equatorial region, and untrapped spreading over all latitudes, including both short‐lived (precipitating) and long‐lived (pseudotrapped) components. In addition, features of the penumbra region around the geomagnetic cutoff were investigated in detail. PAMELA results significantly improve the characterization of the high‐energy albedo proton populations at low‐Earth orbits.
Key Points
A new and accurate study of HE reentrant albedo protons based on PAMELA data
Different components identified and reconstructed by trajectory tracing methods
Significant fluxes of pseudotrapped protons were found in the penumbra region
Silicon drift detectors (SDD) of small dimensions (up to 1
cm
2) have been successfully employed in X-ray spectroscopy due to their small anode geometry, which allows to minimize the electronic noise ...due to the readout device. Many applications, however, require large sensitive areas to be covered (e.g. X-ray astronomy), so that these detectors are effectively impractical. We present the spectroscopic performance of a 53
cm
2 sensitive area, multi-anode SDD, measured at room temperature using an eight-channel readout setup. The measurements, taken using
55Fe and
241Am sources, and X-ray tubes generating energies down to 2
keV, show energy resolutions in the range 290–570
eV FWHM, at 20
°C, depending on the number of anodes collecting the signal. Further developments we are carrying out could improve the detector characteristics and allow to approach the performance of small area SDDs.
Given the good performances in terms of geometrical acceptance and energy resolution, calorimeters are the best suited detectors to measure high energy cosmic rays directly in space. However, in ...order to exploit this potential, the design of calorimeters must be carefully optimized to take into account all limitations related to space missions, due mainly to the mass of the experimental apparatus. CaloCube is a three years R&D project, approved and financed by INFN in 2014, aiming to optimize the design of a space-borne calorimeter by the use of a cubic, homogeneous and isotropic geometry. In order to maximize detector performances with respect to the total mass of the apparatus, comparative studies on different scintillating materials, different sizes of crystals and different spacings among them have been performed making use of Monte Carlo simulations. In parallel to this activity, several prototypes instrumented with CsI:Tl cubic crystals have been constructed and tested with particle beams (muons, electrons, protons and ions). Both simulations and prototypes showed that the CaloCube design leads to a good particle energy resolution (< 2% for electromagnetic showers, < 40% for hadronic showers) and a good effective geometric factor (> 3:5 m2 sr for electromagnetic showers, > 2:5 m2 sr for hadronic showers). Thanks to these performances, in 5 years of operation it would be possible to measure the ux of electrons+positrons up to some tens of TeV and the uxes of protons and nuclei up to some units of PeV/nucleon, hence extending these measurements by at least one order of magnitude in energy compared to the experiments currently operating in space.
A high granularity imaging calorimeter for cosmic-ray physics Boezio, M; Bonvicini, V; Mocchiutti, E ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2002, Letnik:
487, Številka:
3
Journal Article
Recenzirano
Odprti dostop
An imaging calorimeter has been designed and is being built for the PAMELA satellite-borne experiment. The physics goals of the experiment are the measurement of the flux of antiprotons, positrons ...and light isotopes in the cosmic radiation.
The calorimeter is designed to perform a precise measurement of the total energy deposited, to reconstruct the spatial development of the showers (both in the longitudinal and in the transverse directions), and to measure the energy distribution along the shower itself. From this information, the calorimeter will identify antiprotons from an electron background and positrons in a background of protons with an efficiency of about 95% and a rejection power better than 10
−4. Furthermore, a self-trigger system has been implemented with the calorimeter that will be employed to measure high-energy (from about 300
GeV to more than 1
TeV) electrons.
The instrument is composed of 22 layers of tungsten, each sandwiched between two “views” of silicon strip detectors (
X and
Y). The signals are read out by a custom VLSI front-end chip, the CR1.4P, specifically designed for the PAMELA calorimeter, with a dynamic range of 7.14
pC or 1400 minimum ionizing particle (mip).
We report on the simulated performance and prototype design.
The XGS instrument on-board THESEUS Fuschino, F.; Campana, R.; Labanti, C. ...
Journal of physics. Conference series,
10/2016, Letnik:
763, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Consolidated techniques used for space-borne X-ray and gamma-ray instruments are based on the use of scintillators coupled to Silicon photo-detectors. This technology associated with modern very low ...noise read-out electronics allows the design of innovative architectures able to reduce drastically the system complexity and power consumption, also with a moderate-to-high number of channels. These detector architectures can be exploited in the design of space instrumentation for gamma-spectroscopy with the benefit of possible smart background rejection strategies. We describe a detector prototype with 3D imaging capabilities to be employed in future gamma-ray and particle space missions in the 0.002-100 MeV energy range. The instrument is based on a stack of scintillating bars read out by Silicon Drift Detectors (SDDs) at both ends. The spatial segmentation and the crystal double-side readout allow a 3D position reconstruction with ∼3 mm accuracy within the full active volume, using a 2D readout along the two external faces of the detector. Furthermore, one of the side of SDDs can be used simultaneously to detect X-rays in the 2-30 keV energy range. The characteristics of this instrument make it suitable in next generation gamma-ray and particle space missions for Earth or outer space observations, and it will be briefly illustrated.
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