The specially designed GAMMA-400 gamma-ray telescope will realize the measurements of gamma-ray fluxes and cosmic-ray electrons and positrons in the energy range from 100 MeV to several TeV. Such ...measurements concern with the following broad range of scientific topics. Search for signatures of dark matter, investigation of gamma-ray point and extended sources, studies of the energy spectra of Galactic and extragalactic diffuse emission, studies of gamma-ray bursts and gamma-ray emission from the active Sun, as well as high-precision measurements of spectra of high-energy electrons and positrons, protons, and nuclei up to the knee. To clarify these scientific problems with the new experimental data the GAMMA-400 gamma-ray telescope possesses unique physical characteristics comparing with previous and present experiments. For gamma-ray energies more than 100GeV GAMMA-400 provides the energy resolution ∼1% and angular resolution better than 0.02 deg. The methods, developed to reconstruct the direction of incident gamma photon, are presented in this paper, as well as, the capability of the GAMMA-400 gamma-ray telescope to distinguish electrons and positrons from protons in cosmic rays is discussed.
A polarimeter is upgraded and tested in a 200-MeV polarized-proton beam at the accelerator-collider facility of the Brookhaven National Laboratory. The polarimeter is based on the elastic ...polarizedproton scattering on a carbon target at an angle of 16.2°, in which case the analyzing power is close to unity and was measured to a very high degree of precision. It is shown that, in the energy range of 190–205 MeV, the absolute polarization can be measured to a precision better than ±0.5%.
Calorimeters play an important role in cosmic-ray physics and, in particular, in experiments, which are carried out in the atmosphere with balloons and on satellites in space. This paper presents a ...method of energy measurement for protons (at energy higher than 20 GeV) with the help of a thin discrete calorimeter (using as an example the position-sensitive silicon-tungsten calorimeter of the PAMELA experiment) developed based on the data of simulation by the Monte-Carlo method and on the results of test experiment at an accelerator in charged particle beams. The method is based on measurement of the total released energy and on the criterion of event selection, which characterizes the beginning of particle cascade development in the calorimeter. The influence of insertion of additional parameters on the energy resolution obtained with the help of this method is also studied.
We present the energy spectra of protons and helium nuclei of cosmic rays obtained in the PAMELA experiment on board the satellite RESURS-DK1 for the period from August 2006 to December 2009. The ...spectra were measured in the energy range of 100 MeV/nucleon to 100 GeV/nucleon using a magnetic spectrometer within the apparatus. Variations in the solar modulation potential for protons and helium nuclei were calculated on the basis of the monthly mean particle fluxes. A force field model was used to compare the modulation with measurements from balloon experiments, and with measurements from a network of neutron monitors.
The first results from measuring the spectra of solar neutrons with energies of ~10–1000 MeV in the solar flares of 2006–2015 observed by the PAMELA international space experiment are presented. The ...PAMELA neutron detector with
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He counters and a moderator with an area of 0.18 m
2
allows us to estimate the flux of solar neutrons during solar flares. Solar neutrons with energies of ~10–1000 MeV likely occurred in 21 out of the 24 analyzed flares of 2006–2015.
Fluxes of electrons and positrons with energies above ~100 MeV in the near-Earth space are measured with the PAMELA magnetic spectrometer aboard the Resurs DK-1 satellite launched on June 15, 2006, ...into a quasipolar orbit with an altitude of 350–600 km and an inclination of 70°. Calculating the trajectories of detected electrons and positrons in the magnetosphere of the Earth allows us to determine their origin and isolate particles produced during interaction between cosmic rays and the residual atmosphere. Spatial distributions of albedo, quasitrapped, and trapped (in the radiation belt) positrons and electrons are presented. The ratio of positron and electron fluxes suggests that the fluxes of trapped particles of the radiation belt and quasitrapped secondary particles have different mechanisms of formation.
The GAMMA-400 telescope is designed to investigate discrete high-energy gamma-ray sources in the energy range of 0.1–3000 GeV, to measure the energy spectra of galactic and extragalactic diffuse ...gammaray emissions, and to study gamma-ray bursts and gamma-ray emissions from an active Sun. The gamma-ray telescope has an angular resolution of ∼0.01°, an energy resolution of ∼1%, and a proton rejection factor of ∼10
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. Its special assignment is to measure fluxes of gamma rays, electrons, and positrons that could be associated with the annihilation or decay of dark matter particles.
The PAMELA magnetic spectrometer was launched aboard the Resurs DK-1 satellite into a nearpolar circumterrestrial orbit with an altitude of 350–600 km to study fluxes of the particles and ...antiparticles of cosmic rays in the wide energy range of ~80 MeV to several hundred gigaelectronvolts. The results from observations of temporal variations in electron and positron fluxes in 2006–2015 are presented. The ratio of electron and positron fluxes measured in this time interval reveals a dependence on the rigidity of particles, the solar activity, and the polarity of the solar magnetic field.
The GAMMA-400 space observatory will provide precise measurements of gamma rays, electrons, and positrons in the energy range 0.1-3000 GeV. The good angular and energy resolutions, as well as ...identification capabilities (angular resolution ~0.01°, energy resolution ~1%, and proton rejection factor ~10 6 ) will allow us to study the main galactic and extragalactic sources, diffuse gamma-ray background, gamma-ray bursts, and to measure electron and positron fluxes. The peculiar characteristics of the experiment is simultaneous detection of gamma rays and cosmic-ray electrons and positrons, which can be connected with annihilation or decay of dark matter particles.
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