Abstract
Time-dependent energy spectra of galactic cosmic rays (GCRs) carry crucial information regarding their origin and propagation throughout the interstellar environment. When observed at the ...Earth, after traversing the interplanetary medium, such spectra are heavily affected by the solar wind and the embedded solar magnetic field permeating the inner sectors of the heliosphere. The activity of the Sun changes significantly over an 11 yr solar cycle—and so does the effect on cosmic particles; this translates into a phenomenon called solar modulation. Moreover, GCR spectra during different epochs of solar activity provide invaluable information for a complete understanding of the plethora of mechanisms taking place in various layers of the Sun’s atmosphere and how they evolve over time. The High-Energy Particle Detector (HEPD-01) has been continuously collecting data since 2018 August, during the quiet phase between solar cycles 24 and 25; the activity of the Sun is slowly but steadily rising and is expected to peak around 2025/2026. In this paper, we present the first spectra for ∼50–250 MeV galactic protons measured by the HEPD-01 instrument—placed on board the CSES-01 satellite—from 2018 August to 2022 March over a one-Carrington-rotation time basis. Such data are compared to the ones from other spaceborne experiments, present (e.g., EPHIN, Parker Solar Probe) and past (PAMELA), and to a state-of-the-art three-dimensional model describing the GCRs propagation through the heliosphere.
The China Seismo-Electromagnetic Satellite (CSES) aims to monitor electromagnetic, particle, and plasma perturbations in the iono-magnetosphere and inner Van Allen radiation belts originated by ...electromagnetic sources external and internal to the geomagnetic cavity, cosmic rays, and solar events. In particular, the objective of the space mission is to investigate lithosphere-atmosphere-ionosphere coupling mechanisms (including the effects of lightning, earthquakes, volcanoes, and artificial electromagnetic emissions) that induce perturbations of the top side of the ionosphere and lower boundary of the radiation belts. To this purpose, the mission has been conceived to take advantage of a multi-instrument payload comprising nine detectors for the measurement of electromagnetic field components, plasma parameters, and energetic particles, as well as X-ray flux. The Italian team participating in the CSES mission has built one of these devices, the High-Energy Particle Detector (HEPD), for high-precision observations of electrons, protons, and light nuclei. During its trip along the orbit, and thanks to the large set of detectors operated on board, CSES completely monitors the Earth, acting as an excellent instrument for space weather. The satellite was launched on 2018 February 2, with an expected life span of 5 yr. This article describes the CSES mission with a particular focus on the HEPD apparatus and its in-flight performance.
Abstract
High-energy, long gamma-ray bursts (GRBs) can be generated by the core collapse of massive stars at the end of their lives. When they happen in the close-by universe they can be ...exceptionally bright, as seen from the Earth in the case of the recent, giant, long-lasting GRB221009A. GRB221009A was produced by a collapsing star with a redshift of 0.152: this event was observed by many gamma-ray space experiments, which also detected an extraordinary long gamma-ray afterglow. The exceptionally large fluence of the prompt emission of about 0.013 erg cm
−2
illuminated a large geographical region centered on India and including Europe and Asia. We report in this paper the observation of sudden electron flux changes correlated with GRB221009A and measured by the HEPP-L charged particle detector on board the China Seismo-Electromagnetic Satellite, which was orbiting over Europe at the time of the GRB event. The time structure of the observed electron flux closely matches the very distinctive time dependence of the photon flux associated with the main part of the emission at around 13:20 UTC on 2022 October 9. To test the origin of these signals, we set up a simplified simulation of one HEPP-L subdetector: the results of this analysis suggest that the signals observed are mostly due to electrons created within the aluminum collimator surrounding the silicon detector, providing real-time monitoring of the very intense photon fluxes. We discuss the implications of this observation for existing and forthcoming particle detectors on low Earth orbits.
Abstract
In this paper we report the detection of five strong gamma-ray bursts (GRBs) by the High-Energy Particle Detector (HEPD-01) mounted on board the China Seismo-Electromagnetic Satellite, ...operational since 2018 on a Sun-synchronous polar orbit at a ∼507 km altitude and 97° inclination. HEPD-01 was designed to detect high-energy electrons in the energy range 3–100 MeV, protons in the range 30–300 MeV, and light nuclei in the range 30–300 MeV n
−1
. Nonetheless, Monte Carlo simulations have shown HEPD-01 is sensitive to gamma-ray photons in the energy range 300 keV–50 MeV, even if with a moderate effective area above ∼5 MeV. A dedicated time correlation analysis between GRBs reported in literature and signals from a set of HEPD-01 trigger configuration masks has confirmed the anticipated detector sensitivity to high-energy photons. A comparison between the simultaneous time profiles of HEPD-01 electron fluxes and photons from GRB190114C, GRB190305A, GRB190928A, GRB200826B, and GRB211211A has shown a remarkable similarity, in spite of the different energy ranges. The high-energy response, with peak sensitivity at about 2 MeV, and moderate effective area of the detector in the actual flight configuration explain why these five GRBs, characterized by a fluence above ∼3 × 10
−5
erg cm
−2
in the energy interval 300 keV–50 MeV, have been detected.
The functionalization of single-walled carbon nanotubes (SWCNTs) via microwave-assisted grafting reactions enables efficient multidecoration in a single step. A novel water-soluble SWCNT platform was ...prepared via the simple 1,3-dipolar cycloaddition of azomethine ylides under dielectric heating. Thanks to a single grafting reaction the CNT surface binds in a 1 : 1 ratio an amino acidic β-cyclodextrin (β-CD) derivative and the DOTAMA moiety (1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid monoamide). This novel "one shot" synthesis, compared with multistep functionalizations, preserves the SWCNT's structural integrity (TEM images). Besides thermogravimetric analyses, the determination of the amount of β-CD and DOTA moieties grafting onto the SWCNT's surface was performed on the basis of phenolphthalein and gadolinium complexation, respectively.
Diffuse reflectance mid-infrared Fourier transform spectroscopy (DRIFTS) and multivariate statistical analysis methods were used for the identification and classification of honey from different ...floral sources. The 82 honey samples (robinia, chestnut, citrus, polyfloral) were scanned by DRIFTS in the region 4000–600
cm
−1 and also transformed in 1st and 2nd derivatives. Spectral data were analyzed by principal component analysis, general discriminant analysis and classification tree analysis. Classification accuracy near 100% was obtained by discriminant and classification tree analyses. Classification models were successfully validated with one-third leave out method and a classification of about 100% were achieved.
The AMS-02 experiment has been installed in May 2011 on the international space station (ISS) where it will measure, with an unprecedented accuracy, cosmic rays up to the TeV energy region for ...several years. The AMS-02 time of flight (TOF) and the anti-coincide counters (ACC) sub-detectors provide respectively the fast trigger and the veto for the data taking to the experiment. The TOF measures the particle crossing time and the absolute charge with very high precision and provides the fast trigger to AMS-02, whereas the ACC detects and vetoes particles which enter the AMS-02 volume from outside of the main detector acceptance. The electronics of the AMS-02 TOF and ACC sub-detectors have been designed to operate in space for a very long time, in extreme conditions and without any human intervention. In this paper the main design concepts of the TOF-ACC electronics, the space qualification tests and the performance are presented.
The HEPD apparatus for the CSES mission Panico, Beatrice; Osteria, G.; Perfetto, F. ...
Journal of physics. Conference series,
01/2020, Letnik:
1342, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The High-Energy Particle Detector (HEPD) is one of the payloads of the CSES space mission. The HEPD is built by the Italian Limadou collaboration and has different goals. It will study the temporal ...stability of the inner Van Allen radiation belts, the precipitation of trapped particles in the atmosphere and the low energy component of the cosmic rays (5-100 MeV for electrons and 15 - 300 MeV for protons). It has been tested at the Beam Test Facility of the INFN National Laboratory of Frascati, for electrons, and at the Proton Cyclotron of Trento, for protons. Here is presented a study of the performance of the apparatus to separate electrons and protons and identify nuclei up to iron.
The paper describes the design of a readout element, proposed as a radiation monitor, which implements an embedded sensor based on a floating-gate transistor. The paper shows the design of a ...microelectronic circuit composed of a sensor, an oscillator, a modulator, a transmitter and an integrated antenna. A prototype chip has recently been fabricated and tested exploiting a commercial 180nm, four metal CMOS technology. Simulation results of the entire behavior of the circuit before submission are presented along with some measurements of the actual chip response. In addition, preliminary tests of the performance of the Ultra-Wide Band transmission via the integrated antenna are summarized. As the complete chip prototype area is less than 1mm2, the chip fits a large variety of applications, from spot radiation monitoring systems in medicine to punctual measurements of radiation level in High-Energy Physics experiments. A sensitivity of 1mV/rad was estimated within an absorbed dose range up to 10krad and a total power consumption of about 165 μW.
The CSES satellite, developed by Chinese (CNSA) and Italian (ASI) space Agencies, will investigate iono-magnetospheric disturbances (induced by seismicity and electromagnetic emissions of ...tropospheric and anthropogenic origin); will monitor the temporal stability of the inner Van Allen radiation belts and will study the solar-terrestrial coupling by measuring fluxes of cosmic rays and solar energetic particles. In particular the mission aims at confirming the existences (claimed from several analyses) of a temporal correlations between the occurrence of earthquakes and the observation in space of electromagnetic disturbances, plasma fluctiations and anomalous fluxes of high-energy particles precipitating from the inner Van Allen belt. CSES will be launched in the summer of 2017 with a multi-instruments payload able to measure: e.m. fields, charged particles, plasma, TEC, etc. The Italian LIMADOU collaboration will provide the High-Energy Particle Detector (HEPD), designed for detecting electrons (3–200MeV) and proton (30–300MeV)), and participates to develop the Electric Field Detector (EFD) conceived for measuring electric field from ∼DC up to 5MHz.
•On Summer 2017, the CSES satellite will be launched to study the near-Earth e.m., plasma & particles environment.•The scientific objectives are: litho-atmo-ionosphere coupling, seismic precursors, solar-terrestrial physics & cosmic rays.•For CSES, we have built a high-energy particle detector (HEPD) and an electric field detector (EFD).•The article introduces the scientific background, the objectives of CSES and the satellite layout.•We discuss the features of HEPD and EFD, the calibration procedures and the laboratory tests.
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