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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 $${\sim}$$ 300 000, a perigee $${\sim}$$ 500 km, a rotation period $${\sim}$$ 7 days and inclination of 51.4 $${}^{\circ}$$ . 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 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 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. 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, S3, and S4. The thickness of CC2 in this direction is ∼44 X0 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.

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 X0), a time-of-flight system, an imaging calorimeter (2 X0) with tracker, a top shower scintillator detector, an electromagnetic calorimeter from CsI(Tl) crystals (16 X0) 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 × 104.

The GAMMA-400 space project is one of the new generation of space observatories designed to search for signs of dark matter in the cosmic gamma emission, and to measure the characteristics of diffuse gamma-ray emission and gamma-rays from the Sun during periods of solar activity; gamma-ray bursts; extended and point gamma-ray sources; and electron, positron, and cosmic-ray nuclei fluxes with energies in the TeV ranges. The GAMMA-400 γ-ray telescope constitutes the core of the scientific instrumentation. The nature of the intended experiments imposes stringent requirements on the gamma telescope’s system of trigger signal formation, now being developed using the state-of-the-art logic devices and fast data links. The design concept of the system is discussed, along with the chosen engineering solutions and some experimental results obtained during the operation of the system prototype using a positron beam with energies of 100–300 MeV from the PAKHRA S-25R synchrotron at the Lebedev Physical Institute.

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 cm2 sr and the angular resolution is 1°.

The future space-based γ-ray telescope GAMMA-400 will be installed on the Navigator platform of the Russian astrophysical observatory. A highly elliptical orbit will allow prolonged (~100 days) continuous observations of many regions of the celestial sphere for 7–10 years. GAMMA-400 will measure fluxes of γ‑ray emission in the energy range of ~20 MeV to several TeV and electrons + positrons to ~20 TeV. The γ-ray telescope will have excellent separation of γ-ray emissions against the background of cosmic rays and electrons + positrons from protons, along with unprecedented angular (~0.01° at Eγ = 100 GeV) and energy (~1% at Eγ = 100 GeV) resolutions 5–10 times better than for the Fermi-LAT and ground-based γ-ray telescopes. GAMMA-400 observations will provide fundamentally new data on discrete sources and spectra of γ-ray emissions and electrons + positrons.

The GAMMA-400 γ-ray telescope installed at the Russian space observatory is intended for precision measurements in the energy range of 20 MeV–1000 GeV of γ-ray emission (with the angular and energy resolutions several times better than that of current γ-ray telescopes) from discrete sources; measurement of the energy spectra of Galactic and extragalactic diffuse γ-ray emission; studies of γ-ray emission from the active Sun; and measurements of fluxes of γ-ray emission and electron–positron cosmicray component, which are probably associated with the annihilation or decay of dark-matter particles.

The GAMMA-400 currently developing space-based gamma-ray telescope is designed to measure the gamma-ray fluxes in the energy range from ∼20 MeV to several TeV in the highly elliptic orbit (without shadowing the telescope by the Earth) continuously for a long time. The physical characteristics of the GAMMA-400 gamma-ray telescope, especially the angular and energy resolutions (at 100-GeV gamma rays they are ∼0.01° and ∼1%, respectively), allow us to consider this space-based experiment as the next step in the development of extraterrestrial high-energy gamma-ray astronomy. In this paper, a method to improve the reconstruction accuracy of incident angle for low-energy gamma rays in the GAMMA-400 space-based gamma-ray telescope is presented. The special analysis of topology of pair-conversion events in thin layers of converter was performed. Applying the energy dependence of multiple Coulomb scattering for pair components, it is possible to estimate the energies for each particle, and to use these energies as weight in the angle reconstruction procedure. To identify the unique track in each projection the imaginary curvature method is applied. It allows us to obtain significantly better angular resolution in comparison with other methods applied in current space-based experiments. When using this method for 50-MeV gamma rays the GAMMA-400 gamma-ray telescope angular resolution is about 4°.

The GAMMA-400 gamma-ray telescope is planned for the launch at the end of this decade on the Navigator service platform designed by Lavochkin Association on an elliptical orbit with following initial parameters: an apogee ~300000, a perigee ~500 km, a rotation period ~7 days and inclination of 51.4°. The apparatus is expected to operate 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. An electronics system, which consists of 14 front-end multichannel electronics modules and the main processing unit with a total power consumption of about 400 W (74W for main processing unit), has been developed for providing fast trigger and veto for the data taking to the experiment. The communication between front-end modules, main processing unit and scientific data acquisition system of the gamma-ray telescope is performed via high-speed SPACEWIRE network. To assure the long-term reliability in space environment, a series of critical issues such as the radiation hardness, thermal design, components and board level quality control, warm and cold redundancy are taken into consideration. The main design concepts for the system, measurements setups together with some test results are presented.

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.

An array of scintillation detectors of the MONICA Spectrometer, whis is aimed at investigating fluxes of cosmic-ray ions (from H to Ni) in the extraterrestrial space within the energy range from 10 to 300 MeV per nucleon, is considered. The basic goal of the MONICA experiment is the measurement of the ionic and isotopic composition of cosmic rays of the galactic and solar origin, as well as the measurement of their energy spectrum. This problem was intensely studied by numerous investigators [1–10]; nevertheless, a lot of questions remain unsolved up to now, in this field of science. The array of scintillation detectors plays the important role in achieving the goals of the MONICA experiment. The composition of the array, tuning procedure, and characteristics of scintillation detectors are discussed in detail.

The GAMMA-400 project will be the new generation of satellite gamma-observatory. GAMMA-400 space-based gamma-ray telescope represents the core of the scientific complex intended to perform a search for signatures of dark matter in the cosmic gamma-emission, measurements of diffuse gamma-emission characteristics, investigation of extended and point gamma-ray sources, studying of high energy component of gamma-ray bursts and solar flares emission. Four fast plastic sub-detectors of the gamma-ray telescope are included in fast trigger logic in the main telescope aperture. This aperture expected angular and energy resolution are ∼0.01° and ∼1-2% respectively for gammas with the energy >100 GeV and electron/protons rejection factor ∼5-105. Prototype of anticoincidence detector based on long BC-408 scintillators with SiPM readout for gamma-ray telescope was tested on a 300 MeV secondary positron beam of synchrotron C-25P «PAKHRA» of Lebedev Physical Institute in Russia. The measurement setup, design concepts for the prototype detector and chosen solutions together with some test results are discussed. Two other apertures (additional and lateral) allow analyzing transient events not required precision angular resolution, for examples, GRBs and solar flares. Similar plastics sub-detectors included in their fast trigger logic. Using of all three apertures allows making more effective observations of GRBs (better signal to noise ratio), more detailed study of its high energy afterglow due long term measurements (because of high apogee orbit provides low background variations with time) and detailed analysis of the sources luminosity variability (spectral, angular and temporal).

The current status of the MONICA experiment to study fluxes of cosmic ray ions from H to Ni in the energy range of 10–300 MeV in the vicinity of the Earth is described. The main scientific objective of the MONICA experiment is to measure the ionic and isotope compositions and energy spectra of solar cosmic rays for individual solar events, and to study the time evolution of these characteristics. The MONICA experiment will also allow us to investigate the ionic and isotope compositions of the anomalous cosmic ray component, galactic cosmic rays, and fluxes of nuclei in the Earth’s radiation belt. Ion fluxes will be observed using the MONICA large-aperture multilayer semiconductor spectrometer telescope on board a spacecraft in a circumterrestrial polar orbit with an altitude on the order of 600 km. This will enable us to measure the charges of ions with energies over 10 MeV/nucleon by using the Earth’s magnetic field as a charge separator. The geometric factor of the instrument is 100 cm2 sr; its angular resolution is 1°.

The future GAMMA-400 space mission is aimed for the study of gamma rays in the energy range from ~20 MeV up to ~1 TeV. The observations will carry out with GAMMA-400 gamma-ray telescope installed on-board the Russian Space Observatory. We present the detailed description of the architecture and performances of scientific data acquisition system (SDAQ) developing by SRISA for the GAMMA-400 instrument. SDAQ provides the collection of the data from telescope detector subsystems (up to 100 GB per day), the preliminary processing of scientific information and its accumulation in mass memory, transferring the information from mass memory to the satellite high-speed radio line for its transmission to the ground station, the control and monitoring of the telescope subsystems. SDAQ includes special space qualified chipset designed by SRISA and has scalable modular net structure based on fast and high-reliable serial interfaces., 8 pages, 6 figures, ICRC2017

Extraterrestrial gamma-ray astronomy is now a source of new knowledge in the fields of astrophysics, cosmic-ray physics, and the nature of dark matter. The next absolutely necessary step in the development of extraterrestrial high-energy gamma-ray astronomy is the improvement of the physical and technical characteristics of gamma-ray telescopes, especially the angular and energy resolutions. Such a new generation telescope will be GAMMA-400. GAMMA-400, currently developing gamma-ray telescope, together with X-ray telescope will precisely and detailed observe in the energy range of ~20 MeV to ~1000 GeV and 3-30 keV the Galactic plane, especially, Galactic Center, Fermi Bubbles, Crab, Cygnus, etc. The GAMMA- 400 will operate in the highly elliptic orbit continuously for a long time with the unprecedented angular (~0.01{\deg} at E{\gamma} = 100 GeV) and energy (~1% at E{\gamma} = 100 GeV) resolutions better than the Fermi-LAT, as well as ground gamma-ray telescopes, by a factor of 5-10. GAMMA-400 will permit to resolve gamma rays from annihilation or decay of dark matter particles, identify many discrete sources (many of which are variable), to clarify the structure of extended sources, to specify the data on the diffuse emission., Comment: 8 pages, 9 figures, ICRC2017

Fermi-LAT has made a significant contribution to the study of high-energy gamma-ray diffuse emission and the observation of ~3000 discrete sources. However, one third of all gamma-ray sources (both galactic and extragalactic) are unidentified, the data on the diffuse gamma-ray emission should be clarified, and signatures of dark matter particles in the high-energy gamma-ray range are not observed up to now. GAMMA-400, currently developing gamma-ray telescope, will have the angular (~0.01° at 100 GeV) and energy (~1% at 100 GeV) resolutions in the energy range of 10-1000 GeV better than the Fermi-LAT (as well as ground gamma-ray telescopes) by a factor of 5-10 and observe some regions of the Universe (such as Galactic Center, Fermi Bubbles, Crab, Cygnus, etc.) in the highly elliptic orbit (without shading the telescope by the Earth) continuously for a long time. It will permit to identify many discrete sources, to clarify the structure of extended sources, to specify the data on the diffuse emission, and to resolve gamma rays from dark matter particles.

Fermi-LAT has made a significant contribution to the study of high-energy gamma-ray diffuse emission and the observations of 3000 discrete sources. However, one third of all gamma-ray sources (both galactic and extragalactic) are unidentified, the data on the diffuse gamma-ray emission should be clarified, and signatures of dark matter particles in the high-energy gamma-ray range are not observed up to now. GAMMA-400, the currently developing gamma-ray telescope, will have angular (∼0.01∘ at 100 GeV) and energy (∼1% at 100 GeV) resolutions in the energy range of 10–1000 GeV which are better than Fermi-LAT (as well as ground gamma-ray telescopes) by a factor of 5–10. It will observe some regions of the Universe (such as the Galactic Center, Fermi Bubbles, Crab, Cygnus, etc.) in a highly elliptic orbit (without shading the telescope by the Earth) continuously for a long time. It will allow us to identify many discrete sources, to clarify the structure of extended sources, to specify the data on the diffuse emission, and to resolve gamma rays from dark matter particles.

The present contribution is dedicated to the investigation of the background conditions for cosmic ray ion ionization state measurements in MONICA experiment. The future experiment MONICA is aimed to study the cosmic ray ion fluxes from H till Ni in energy range 10-300 MeV/n. The experiment main scientific objective is the measurement of the ion ionization state, as well as elemental, isotope composition and energy spectra of Solar Energetic Particle (SEP), Anomalous (ACR) and Galactic (GCR) cosmic ray fluxes. The observation of the ion fluxes will be carried out with high acceptance multilayer semiconductor telescope-spectrometer MONICA installed onboard satellite. The satellite orbit parameters (circular, altitude is about 600 km, polar) were chosen for the realization of the unique method for the measurement of the charge state of the ions with energies >10 MeV/n based on the usage of the Earth magnetic field as a separator of ion charge. To realize the method of the geomagnetic separator it is necessary to detect ions in the Earth magnetosphere at geomagnetic L-shells L

The GAMMA-400 gamma-ray telescope is intended to measure the fluxes of gamma-rays and cosmic-ray electrons and positrons in the energy range from 100 MeV to several TeV. Such measurements concern the following scientific tasks: investigation of point sources of gamma-rays, studies of the energy spectra of Galactic and extragalactic diffuse emission, studies of gamma-ray bursts and gamma-ray emission from the Sun, as well as high precision measurements of spectra of high-energy electrons and positrons. Also the GAMMA- 400 instrument provides the possibility for protons and nuclei measurements up to knee. But the main goal for the GAMMA-400 mission is to perform a sensitive search for signatures of dark matter particles in high-energy gamma-ray emission. To fulfill these measurements the GAMMA-400 gamma-ray telescope possesses unique physical characteristics in comparison with previous and present experiments. The major advantage of the GAMMA-400 instrument is excellent angular and energy resolution for gamma-rays above 10 GeV. The GAMMA-400 experiment will be installed onboard of the Navigator space platform, manufactured by the NPO Lavochkin Association. The expected orbit will be a highly elliptical orbit (with apogee 300.000 km and perigee 500 km) with 7 days orbital period. An important profit of such an orbit is the fact that the full sky coverage will always be available for gamma ray astronomy.

The GAMMA-400 gamma-ray telescope with excellent angular and energy resolutions is designed to search for signatures of dark matter in the fluxes of gamma-ray emission and electrons + positrons. Precision investigations of gamma-ray emission from Galactic Center, Crab, Vela, Cygnus, Geminga, and other regions will be performed, as well as diffuse gamma-ray emission, along with measurements of high-energy electron + positron and nuclei fluxes. Furthermore, it will study gamma-ray bursts and gamma-ray emission from the Sun during periods of solar activity. The GAMMA-400 energy range is expected to be from ~20 MeV up to TeV energies for gamma rays, up to 10 TeV for electrons + positrons, and up to 1015 eV for cosmic-ray nuclei. For 100-GeV gamma rays, the GAMMA-400 angular resolution is ~0.01° and energy resolution is ~1%; the proton rejection factor is ~5x105. GAMMA-400 will be installed onboard the Russian space observatory.[object Object]

We discuss the results of comparison and optimization of (ΔE − E) methods for identifying nuclei with the aid of a multilayer Si detector that will be used in the MONICA satellite-based experiment aimed at studying the nuclear component of cosmic rays from hydrogen to nickel in the energy range of 10–300 MeV/nucleon. The residual-range and Bethe-Bloch curve approximation methods are considered. Using the GEANT4 simulation, it is shown that the Bethe-Bloch curve approximation method not only ensures a better mass resolution (which is particularly important for identification of heavy nuclei), but also provides a means for identifying “drift” nuclei with satisfactory charge (

The GAMMA-400 gamma-ray telescope with excellent angular and energy resolutions is designed to search for signatures of dark matter in the fluxes of gamma-ray emission and electrons + positrons. Precision investigations of gamma-ray emission from Galactic Center, Crab, Vela, Cygnus, Geminga, and other regions will be performed, as well as diffuse gamma-ray emission, along with measurements of high-energy electron + positron and nuclei fluxes. Furthermore, it will study gamma-ray bursts and gamma-ray emission from the Sun during periods of solar activity. The energy range of GAMMA-400 is expected to be from ~20 MeV up to TeV energies for gamma rays, up to 20 TeV for electrons + positrons, and up to 10E15 eV for cosmic-ray nuclei. For high-energy gamma rays with energy from 10 to 100 GeV, the GAMMA-400 angular resolution improves from 0.1{\deg} to ~0.01{\deg} and energy resolution from 3% to ~1%; the proton rejection factor is ~5x10E5. GAMMA-400 will be installed onboard the Russian space observatory., Comment: 8 pages, 2 figures, 2 tables, submitted to the proceedings of ICRC2015

PAMELA is a satellite-borne experiment which will measure the antiparticle component of cosmic rays over an extended energy range and with unprecedented accuracy. The apparatus consists of a perman ...

The results from observing bursts of high-energy charged particle fluxes in near-Earth space, caused by local disturbances of the radiation belt and particles precipitating from it, in the ARINA (on board the RESURS-DKI satellite since 2006) and VSPLESK (on board the International Space Station since 2008) satellite experiments are presented. New features were revealed in the geographic distribution of particle bursts, indicating that most high-energy electron bursts are interrelated with thunderstorm and seismic activities, at that some bursts are observed in regions of tectonic faults. Results from observing high-energy electron precipitation from the radiation belt over Japan during the powerful seismic event that began on March 11, 2011, are analyzed.

In this paper we report on the energy spectrum of protons of albedo origin measured by the instruments NINA and NINA-2 at different geomagnetic locations, and the behaviour of the proton flux as a function of altitude out of the South Atlantic Anomaly. The instrument NINA was used on board the satellite Resurs-01-N4 between 1998 and 1999, at an altitude of about 830 km. The NINA-2 apparatus, on board the satellite MITA, was put into orbit in July 2000, at an altitude of about 450 km. A detailed understanding of the fluxes of charged particles in near Earth orbit is important to reach an accurate theoretical description of the Earth’s magnetic field, but also as input for the calculation of the back-ground for scientific instruments aboard satellites, like the future AGILE and GLAST g astronomy telescopes.Key words. Magnetospheric physics (energetic particles, trapped; instruments and techniques)

A method for simulating the propagation processes for ions of the anomalous component of cosmic rays in the Earth's magnetic field is described with allowance made for a step-by-step stripping of the ions in the residual atmosphere and their trapping by the geomagnetic field. Numerical results are presented for the geomagnetic trapping of high-energy singly charged oxygen ions penetrating into the stripping region from interplanetary space.

The NINA apparatus, on board the Russian satellite Resurs-01 n.4, has been in polar orbit since 1998 July 10, at an altitude of 840 km. Its main scientific task is to study the galactic, solar and anomalous components of cosmic rays in the energy interval 10--200 MeV/n. In this paper we present a description of the instrument and its basic operating modes. Measurements of Galactic Cosmic Ray spectra will also be shown.

Based on the available experimental data and the results of calculations carried out in this paper, cross sections are estimated for single-electron stripping of OZ+ (Z=1–7) ions with energies in the range E=0.5–200 MeV/u due to collisions with H, He, N, O, or Ar atoms. Analytical approximations of the cross sections are presented.

The Pamela apparatus will allow precise measurements of cosmic rays in Low Earth Orbit, mainly focusing on the antiparticles component. The apparatus is now ready for flight, and the launch is foreseen during June 2006. The paper briefly reports the status of the experiment, and the performances of the various components as measured before the launch.

The present contribution is dedicated to the investigation of the background conditions for cosmic ray ion ionization state measurements in MONICA experiment [1]. The future experiment MONICA is aimed to study the cosmic ray ion fluxes from H till Ni in energy range 10-300 MeV/n by multilayer semiconductor telescope-spectrometer installed onboard satellite. The satellite orbit parameters (circular, altitude is about 600 km, polar) were chosen for the realization of the unique method for the measurement of the charge state of the ions with energies >10 MeV/n by using the Earth magnetic field as a separator of ion charge. The analysis of the background particle fluxes is presented taking into account the recent data of the satellite experiments and known AE-8, AP-8 models and elaborated the recommendations to improve the background conditions for the MONICA experiment.

The GAMMA-400 gamma-ray space-based telescope has as its main goals to measure cosmic γ-ray fluxes and the electron-positron cosmic-ray component produced, theoretically, in dark-matter-particles decay or annihilation processes, to search for discrete γ-ray sources and study them in detail, to examine the energy spectra of diffuse γ-rays — both galactic and extragalactic — and to study gamma-ray bursts (GRBs) and γ-rays from the active Sun. Scientific goals of GAMMA-400 telescope require fine angular resolution. The telescope is of a pair-production type. In the converter-tracker, the incident gamma-ray photon converts into electron-positron pair in the tungsten layer and then the tracks are detected by silicon- strip position-sensitive detectors. Multiple scattering processes become a significant obstacle in the incident-gamma direction reconstruction for energies below several gigaelectronvolts. The method of utilising this process to improve the resolution is proposed in the presented work.

Studying high-energy (>50GeV) cosmic gamma radiation raises a problem of selection of neutral gamma rays from a background of charged particles. The problem is embarrassed by the backsplash effect. The backsplash consists, in the main, of low-energy (1 MeV) secondary photons moving backwards and is produced by any high-energy gamma quantum. A charged-particle rejection method using the anticoincidence and time-of-flight systems is proposed. Charged-particle events are distinguished from those being triggered by high-energy gamma-rays producing backsplash. The method is based on the time separation of signals. It allows us to keep the gamma-ray detection efficiency high up to high energies.

We described an approach suitable for obtaining an analytical expression for the energy of an antiphase boundary in an ordered alloy in the hard sphere model using pair interatomic interaction potentials. Depending on the orientation of the antiphase boundary, the crystal is subdivided into two-dimensional monatomic packings parallel to the defect, and its energy is determined by the sum of the energies of the two-dimensional packings. The results of the calculations for antiphase boundaries of different orientations are given in the form of matrix expressions for each of the considered superstructures.

The flux of energetic light ions at low altitude is both an important input and output for self-consistent calculations of albedo particles resulting from the interaction of trapped and cosmic ray particles, with the upper atmosphere. In addition, data on the flux of light ions are needed to evaluate radiation damages on space-borne instruments and on space mission crews. In spite of that, sources of data on the flux of energetic ions at LEO are roughly limited to the AP-8 model, CREME/CREME96 codes and the SAMPEX, NOAA/TIROS satellites. The existing and operational European SAC-C/ICARE and PROBA-1/SREM instruments could also be potential sources for proton data at LEO. Although AP-8 and SAMPEX/PSB97 may be publicly accessed through the SPENVIS, they exhibit an order of magnitude difference in low altitude proton fluxes and they do not contain helium fluxes. Therefore, improved light ion radiation models are still needed. In this paper we present a procedure to identify and measure the energy of ions that are not stopped in the NINA-2 instrument. Moreover, problems related to particles that cross the instrument in the opposite direction are addressed and shown to be a possible cause of particle misidentification. Measuring fluxes of low abundance elements like energetic helium ions requires a good characterisation of all possible sources of backgrounds in the detector. Hints to determine the several contributions to the background are presented herein and may be applied to extract an order of magnitude of energetic ions fluxes from existing data sets, while waiting for dedicated high performance instruments.

The future onboard experiment MONICA (monitor of cosmic ray nuclei and ions) is aimed for studying the cosmic ray ion fluxes from H to Ni in the energy range 10-300 MeV/n in vicinity of Earth. It's main scientific objective is the measurement of ion ionization states, as well as elemental, isotope composition and energy spectra of Solar Energetic Particle (SEP) fluxes. The method of the ion ionization state measurement based on the usage of Earth magnetic field as a separator of particle charge will be utilized in this experiment. The present contribution is dedicated to investigate the possibilities and features of this method for the MONICA experiment. The real time dependences of inverse square of cut-off geomagnetic L-shell (LC-2) on magnetic rigidity (R) in rigidity range 640-2780 MV were studied experimentally during powerful SEP events December 13-15 2006. The possibility to simulate these dependences using the modern geomagnetic field models is analyzed as well.

The NINA detector on board the Resurs-01 No. 4 satellite (835 km, 98° inclination) is equipped with particle trackers based on silicon strip detectors. From the energy deposited in each of its silicon layers the mass, the momentum direction and energy of incident particles have been determined. The resolutions in mass and energy allow identification of H and He isotopes over the 10-50 MeV/n energy range. The angular resolution is about 2.5°. We present the direct measurements of proton and helium isotopes pitch angle distributions derived from Resurs-01 No.4/NINA observations and their variations as functions of (B, L) coordinates and energy. The measurements of trapped helium isotopes spectrum are also presented.

PAMELA is a satellite-borne experiment that will study the antiproton and positron fluxes in cosmic rays in a wide range of energy (from 80 MeV up to 190 GeV for antiprotons and from 50 MeV up to 270 GeV for positrons) and with high statistics, and that will measure the antihelium/helium ratio with a sensitivity of the order of 10/sup -8/. The detector will fly on-board a polar orbiting Resurs DK1 satellite, which will be launched into space by a Soyuz rocket in 2004 from Baikonur cosmodrome in Kazakhstan, for a 3-year-long mission. Particle identification and energy measurements are performed in the PAMELA apparatus using the following subdetectors: a magnetic spectrometer made up of a permanent magnet equipped with double-sided microstrip silicon detectors, an electromagnetic imaging calorimeter composed of layers of tungsten absorber and silicon detectors planes, a transition radiation detector made of straw tubes interleaved with carbon fiber radiators, a plastic scintillator time-of-flight and trigger system, a set of anticounter plastic scintillator detectors, and a neutron detector. The features of the detectors and the main results obtained in beam test sessions are presented.

We present in this paper a status report of the space experiment PAMELA. PAMELA is a satellite-borne experiment which primarily aims to measure the antiproton and positron spectra in the cosmic rad ...

[1] In this paper we report on the energy spectra and abundance ratios of hydrogen and helium isotopes of albedo origin, measured by the instruments NINA and NINA-2 in near-equatorial regions. The instrument NINA flew on board the satellite Resurs-01-N4 between 1998 and 1999, at a 830 km average altitude. The NINA-2 apparatus, on board the satellite MITA, was put into orbit in July 2000 at an altitude of about 450 km. NINA and NINA-2 measurements revealed that 2H, 3H, 3He, and 4He are a significant portion of the secondary flux above the atmosphere. The energy spectra of hydrogen isotopes are practically flat across the energy range of 10–40 MeV/n, while the spectra of helium isotopes can be fitted by a power law of spectral indexes γ = 0.8 and γ = 1.5 for 3He and 4He, respectively.

In June 1998 the telescope NINA will be launched in space on board of the Russian satellite Resource-01 n.4. The main scientific objective of the mission is the study of the anomalous, galactic and solar components of the cosmic rays in the energy interval 10–200 MeV/n. The core of the instrument is a silicon detector whose performances have been tested with a particle beam at the GSI Laboratory in Germany in 1997; we report here on the results obtained during the beam calibration.

The results of the observation of bursts of high-energy charged particle fluxes in the near-Earth space, caused by local disturbances of the radiation belt and particle precipitation from it, in satellite experiments ARINA (on board the Resurs-DK1 from 2006) and VSPLESK (on board the International Space Station from 2008) are presented. New specialties were revealed in geographical distribution of particle bursts, pointing out that the large part of high- energy electron bursts interrelates with thunderstorm and seismic activities, at that some part of bursts locates in the regions of tectonic faults. Results of observation of high-energy electron precipitation from the radiation belt over the Japan region during the powerful seismic event, started on March 11, 2011, are analyzed.

[1] The detector New Instrument for Nuclear Analysis (NINA) aboard the satellite Resurs-01-N4 detected hydrogen and helium isotopes geomagnetically trapped, while crossing the South Atlantic Anomaly. Deuterium and tritium at L shell < 1.2 were unambiguously recognized. The 3He and 4He power law spectra, reconstructed at L shell = 1.2 and B < 0.22 G, have indices equal to 2.30 ± 0.08 in the energy range 12–50 MeV nucleon−1 and 3.4 ± 0.2 in 10–30 MeV nucleon−1, respectively. The measured 3He/4He ratio and the reconstructed deuterium profile as a function of L shell bring one to the conclusion that the main source of radiation belt light isotopes at Resurs altitudes (∼800 km) and for energy greater than 10 MeV nucleon−1 is the interaction of trapped protons with residual atmospheric helium.