The future space-based GAMMA-400
-ray telescope will operate onboard the Russian astrophysical observatory in a highly elliptic orbit during 7 years. Observing
-ray sources from Galactic plane,
-ray ...bursts,
-ray diffuse emission,
rays from the Sun, and
rays from dark matter particles will be performed uninterruptedly for a long time (
100 days) in point-source mode in contrast to scanning mode for Fermi-LAT and other space- and ground-based instruments. GAMMA-400 will measure
rays in the energy range from
20 MeV to several TeV units, have the unprecedented angular (
at
GeV) and energy (
at
GeV) resolutions better than for Fermi-LAT, as well as ground-based
-ray facilities, by a factor of 5–10, and perfectly separate
rays from cosmic-ray background.
The space-based GAMMA-400 gamma-ray telescope will measure the fluxes of gamma rays in the energy range from ∼20 MeV to several TeV and cosmic-ray electrons and positrons in the energy range from ...several GeV to several TeV to investigate the origin of gamma-ray sources, sources and propagation of the Galactic cosmic rays and signatures of dark matter. The instrument consists of an anticoincidence system, a converter-tracker (thickness one radiation length, 1
X
0
), a time-of-flight system, an imaging calorimeter (2
X
0
) with tracker, a top shower scintillator detector, an electromagnetic calorimeter from CsI(Tl) crystals (16
X
0
) with four lateral scintillation detectors and a bottom shower scintillator detector. In this paper, the capability of the GAMMA-400 gamma-ray telescope for electron and positron measurements is analyzed. The bulk of cosmic rays are protons, whereas the contribution of the leptonic component to the total flux is ∼10
−3
at high energy. The special methods for Monte Carlo simulations are proposed to distinguish electrons and positrons from proton background in the GAMMA-400 gamma-ray telescope. The contribution to the proton rejection from each detector system of the instrument is studied separately. The use of the combined information from all detectors allows us to reach a proton rejection of up to ∼1 × 10
4
.
The future space-based GAMMA-400 gamma-ray telescope will operate onboard the Russian astrophysical observatory in a highly elliptic orbit during 7 years to observe Galactic plane, Galactic Center, ...Fermi Bubbles, Crab, Vela, Cygnus X, Geminga, Sun, and other regions and measure gamma- and cosmic-ray fluxes. Observations will be performed in the point-source mode continuously for a long time (∼100 days). GAMMA-400 will measure gamma rays in the energy range from ∼ 20 MeV to several TeV and cosmic-ray electrons + positrons up to several tens TeV. GAMMA-400 instrument will have very good angle and energy resolutions, high separation efficiency of gamma rays from cosmic-ray background, as well as electrons + positrons from protons. The main feature of GAMMA-400 is the unprecedented angular resolution for energies > 30 GeV better than the space-based and ground-based gamma-ray telescopes by a factor of 5–10. GAMMA-400 observations will permit to resolve gamma rays from annihilation or decay of dark matter particles, identify many discrete sources, clarify the structure of extended sources, specify the data on cosmic-ray electron + positron spectra.
•The GAMMA-400 gamma-ray telescope performance for lateral aperture.•Detection of GRB from the lateral aperture in the energy range from ∼ 10 to ∼ 100 MeV.•The problem of connection between high- and ...low-energy gamma-ray emissions of GRBs.
The currently developing space-based gamma-ray telescope GAMMA-400 will measure the gamma-ray and electron + positron fluxes using the main top-down aperture in the energy range from ∼ 20 MeV to several TeV in a highly elliptic orbit (without shading the telescope by the Earth and outside the radiation belts) continuously for a long time. The instrument will provide fundamentally new data on discrete gamma-ray sources, gamma-ray bursts (GRBs), sources and propagation of Galactic cosmic rays and signatures of dark matter due to its unique angular and energy resolutions in the wide energy range. The gamma-ray telescope consists of the anticoincidence system (AC), the converter-tracker (C), the time-of-flight system (S1 and S2), the position-sensitive and electromagnetic calorimeters (CC1 and CC2), scintillation detectors (S3 and S4) located above and behind the CC2 calorimeter and lateral detectors (LD) located around the CC2 calorimeter.
In this paper, the capabilities of the GAMMA-400 gamma-ray telescope to measure fluxes of GRBs from lateral directions of CC2 are analyzed using Monte-Carlo simulations. The analysis is based on off-line second-level trigger construction using signals from S3, CC2, S4 and LD detectors. For checking the numerical algorithm the data from space-based GBM and LAT instruments of the Fermi experiment are used, namely, three long bursts: GRB 080916C, GRB 090902B, GRB 090926A and one short burst GRB 090510A. The obtained results allow us to conclude that from lateral directions the GAMMA-400 space-based gamma-ray telescope will reliably measure the spectra of bright GRBs in the energy range from ∼ 10 to ∼ 100 MeV with the on-axis effective area of about 0.13 m2 for each of the four sides of CC2 and total field of view of about 6 sr.
The GAMMA-400 gamma-ray telescope is planned for the launch at the end of 2026 on the Navigator service platform designed by Lavochkin Association on an elliptical orbit with following initial ...parameters: an apogee
300 000, a perigee
500 km, a rotation period
7 days and inclination of 51.4
. The apparatus is expected to operate for more than 5 years, reaching an unprecedented sensitivity for the search of dark matter signatures and the study of the unresolved and so far unidentified gamma-ray sources. The segmented anticoincidence counters surround the converter-tracker and calorimeter of the telescope with the purpose of vetoing to assure a clean track reconstruction and charged particle background suppression. The anticoincidence detector prototype based on long BC-408 scintillator with silicon photomultipliers readout was tested using 300-MeV positron beam of synchrotron C-25P ‘‘PAKHRA’’ of Lebedev Physical Institute. The measurement setup, design concepts for the prototype detector together with test results are discussed.
The future GAMMA-400 γ-ray telescope will provide fundamentally new data on discrete sources and spectra of γ-ray emissions and electrons + positrons due to its unique angular and energy resolutions ...in the wide energy range from 20 MeV up to several TeV. The γ-ray telescope consists of the anticoincidence system (AC), the converter-tracker (C), the time-of-flight system (S1 and S2), the position-sensitive and electromagnetic calorimeters (CC1 and CC2), the scintillation detectors of the calorimeter (S3 and S4) and lateral anticoincidence detectors of the calorimeter (LD). To extend the GAMMA-400 capabilities to measure γ-ray bursts, Monte-Carlo simulations were performed for lateral aperture of the one of the versions of GAMMA-400. Second-level trigger based on signals from CC2, LD, S3, and S4 allows us to detect γ-ray bursts in the energy range of ~10-300 MeV with high effective area about 1 m2.
Cosmophysical Research with GAMMA-400 Topchiev, N. P.; Galper, A. M.; Arkhangelskaja, I. V. ...
Physics of atomic nuclei,
08/2023, Volume:
86, Issue:
4
Journal Article
Peer reviewed
The GAMMA-400 gamma-ray telescope is the successor of Soviet and Russian gamma-ray telescopes. GAMMA-400 is being developed for cosmophysical research in accordance with the Russian Federal Space ...Program 2016–2025. The GAMMA-400 experiment will be implemented aboard the Russian astrophysical space observatory in a highly elliptic orbit during 7 years to provide new data on gamma-ray emission mainly from the Galactic plane, Galactic Center, the Sun and cosmic-ray electron
positron fluxes. The main mode of observations will be the continuous point-source mode with the duration of up to
100 days. The GAMMA-400 gamma-ray telescope will study high-energy gamma-ray emission up to several TeV and cosmic-ray electrons
positrons up to 20 TeV. GAMMA-400 will have the never-achieved angular resolution, the high-energy and time resolutions, as well as very good separation efficiency of gamma rays from cosmic-ray background and of electrons
positrons from protons. The distinctive features of GAMMA-400 are the excellent angular resolution of
at
GeV that exceeds resolutions of the space-based and ground-based gamma-ray telescopes by a factor of 5–10, as well as high-energy resolution of
at
GeV. GAMMA-400 studies can discover gamma-ray emission from annihilation or decay of dark matter particles, identify many unassociated discrete sources, explore the structure of extended sources, search for gamma-ray bursts and solar gamma-ray flares, improve the data on cosmic-ray electron
positron spectra for energies of >50 GeV.
The space observatory GAMMA-400 is processed currently in accordance with the Federal Space Program of the Russian Federation for 2016–2025. The observatory includes a gamma-ray telescope for ...experimental studies of gamma rays in the energy range from ~20 MeV to ~1 TeV with high angular and energy resolution, as well as for research of electrons + positrons at energies above 100 GeV in both the main (top-down), and lateral apertures. At present time, there are experimental indications concerning the possibility of existing of spectrum break in electrons + positrons intensities about TeV energies. This point stimulates several speculations to explain such phenomena. In this paper we examined capabilities of GAMMA-400 telescope to explore this problem. The methods for electron detection in the energy range from 100 GeV up to 10 TeV from the lateral aperture of a gamma-ray telescope are presented. Also, the results of calculation for proton rejection factor and for electron acceptance are revealed.
The MONICA satellite-based experiment is described. In this experiment, fluxes of cosmic-ray ions from H to Ni are investigated near the Earth in the energy range of 10–300 MeV/nucleon. The main ...scientific objectives of the MONICA experiment are to measure the ion and isotope compositions and the energy spectra of solar cosmic rays for individual solar events and to study the evolution of these characteristics over time. The MONICA experiment will help to investigate the ion and isotope composition of the anomalous component of cosmic rays, galactic cosmic rays, and nuclear fluxes in the Earth’s radiation belt. Observations of ion fluxes will be carried out using the MONICA high-aperture multilayer semiconductor spectrometer–telescope installed on board a spacecraft with a low-Earth circular polar orbit at a height of approximately 600 km. This orbit will make it possible to perform the method for measuring the charge of ions with energies above 10 MeV/nucleon, which is based on the use of the Earth’s magnetic field as a particle- charge separator. The geometric factor of the instrument is 100 cm
2
sr and the angular resolution is 1°.
The GAMMA-400 (Gamma Astronomical Multifunctional Modular Apparatus) will be a new generation satellite gamma-observatory. The gamma-ray telescope GAMMA-400 consists of the anticoincidence system ...(top and lateral sections—ACtop and AClat), the converter-tracker (
C
), the time-of-flight system TOF (two sections
S
1 and
S
2), the position-sensitive and electromagnetic calorimeters (CC1 and CC2), the scintillation detectors of the calorimeter (
S
3 and
S
4) and lateral anticoincidence detectors of the calorimeter LD. Two apertures used for observation of transient events do not require the best angular resolution as for the gamma-ray bursts and solar flares from both upper and lateral directions. Additional aperture allows the particle registering from upper direction, which do not interact with converter-tracker and do not form a TOF signal. The lateral aperture allows registering of γ-quanta in perpendicular direction with respect to main axis of GAMMA-400 due to CC2, LD,
S
3, and
S
4. The thickness of CC2 in this direction is ∼44
X
0
and this allows detection of gammas, electrons and positrons with energies up to 10 TeV. The results of calculation of the fractal dimension of temporal profiles of additional aperture prototype of GAMMA-400 during its calibration using secondary positron beam of the synchrotron C-25P “PAKHRA” of Lebedev Physical Institute confirm the absence of any correlation between the AC and CC1 characteristics and correspondence of additional aperture background to Poisson statistics or Erlang one with shape parameter up to 10.
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