M. F. Runtso

Measurement of the flux of primary cosmic ray antiprotons with energies of 60 MeV to 350 GeV in the PAMELA experiment

It is interesting to measure the antiproton galactic component in cosmic rays in order to study the mechanisms by which particles and antiparticles are generated and propagate in the Galaxy and to search for new sources of, e.g., annihilation or decay of dark matter hypothetical particles. The antiproton spectrum and the ratio of the fluxes of primary cosmic ray antiprotons to protons with energies of 60 MeV to 350 GeV found from the data obtained from June 2006 to January 2010 in the PAMELA experiment are presented. The usage of the advanced data processing method based on the data classification mathematical model made it possible to increase statistics and analyze the region of higher energies than in the earlier works.

Design and performance of the GAMMA-400 gamma-ray telescope for dark matter searches

The GAMMA-400 gamma-ray telescope is designed to measure the fluxes of gamma-rays and cosmic-ray electrons + positrons, which can be produced by annihilation or decay of the dark matter particles, as well as to survey the celestial sphere in order to study point and extended sources of gamma-rays, measure energy spectra of Galactic and extragalactic diffuse gamma-ray emission, gamma-ray bursts, and gamma-ray emission from the Sun. GAMMA-400 covers the energy range from 100 MeV to 3000 GeV. Its angular resolution is ∼0.01° (Eγ > 100 GeV), the energy resolution ∼1% (Eγ > 10 GeV), and the proton rejection factor ∼106. GAMMA-400 will be installed on the Russian space platform Navigator. The beginning of observations is planned for 2018.

The GAMMA-400 experiment: Status and prospects

The development of the GAMMA-400 γ-ray telescope continues. The GAMMA-400 is designed to measure fluxes of γ-rays and the electron-positron cosmic-ray component possibly associated with annihilation or decay of dark matter particles; and to search for and study in detail discrete γ-ray sources, to measure the energy spectra of Galactic and extragalactic diffuse γ-rays, and to study γ-ray bursts and γ-rays from the active Sun. The energy range for measuring γ-rays and electrons (positrons) is from 100 MeV to 3000 GeV. For 100-GeV γ-rays, the γ-ray telescope has an angular resolution of ∼0.01°, an energy resolution of ∼1%, and a proton rejection factor of ∼5 × 105. The GAMMA-400 will be installed onboard the Russian Space Observatory.

Measurements of quasi-trapped electron and positron fluxes with PAMELA

This paper presents precise measurements of the differential energy spectra of quasi-trapped secondary electrons and positrons and their ratio between 80 MeV and 10 GeV in the near-equatorial regio ...

GAMMA-400 gamma-ray observatory

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.

Characteristics of the GAMMA-400 gamma-ray telescope for searching for dark matter signatures

The GAMMA-400 gamma-ray telescope currently under development is designed to measure fluxes of gamma rays and electron-positron cosmic-ray components, which could be associated with the annihilation or decay of dark matter particles, and to survey in detail the celestial sphere in order to search for and investigate discrete gamma-ray sources; to measure the energy spectra of Galactic and extragalactic dif- fuse gamma-ray emissions; and to study gamma-ray bursts and the gamma-ray emissions of active Sun. The GAMMA-400 energy range is 100 MeV to 3000 GeV. The gamma-ray telescope has an angular resolution of ∼0.01°, an energy resolution of ∼1%, and a proton rejection factor of ∼106. The GAMMA-400 will be installed on Russia’s Navigator space platform. Observations are planned to commence in 2018.

Solar modulation of the spectra of protons and helium nuclei in the PAMELA experiment

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 PAMELA space experiment: first year of operation

On the 15th of June 2006 the PAMELA experiment, mounted on the Resurs DK1 satellite, was launched from the Baikonur cosmodrome and it has been collecting data since July 2006. PAMELA is a satellite ...

Precision, absolute proton polarization measurements at 200 MeV beam energy

A new polarimeter for absolute proton beam polarization measurements at 200 MeV to accuracy better than ?0.5% has been developed as a part of the RHIC polarized source upgrade. The polarimeter is based on the elastic proton-carbon scattering at 16.2? angle, where the analyzing power is close to 100% and was measured with high accuracy. The elastically and in-elastically scattered protons are clearly identified by the difference in the propagation through variable copper absorber and energy deposition of the protons in the detectors. The elastic scattering polarimeter was used for calibration of a high rate inclusive 12? polarimer for the on-line polarization tuning and monitoring. This technique can be used for accurate polarization measurements in energy range of at least 160?250 MeV.

Measuring fluxes of the protons and helium nuclei of high-energy cosmic rays

Techniques for measuring helium nuclei and proton energy spectra in circumterrestrial space were developed on the basis of simulated data and data from the position-sensitive silicon-tungsten calorimeter in the PAMELA satellite experiment. The thickness of the calorimeter is 0.6 nuclear interaction lengths. In this work, the experimental results for the measured energy spectra of the protons and helium nuclei of cosmic rays with energies above 50 GeV are presented.