The preliminary results from measurements of deuteron fluxes in galactic cosmic rays (GCR) in the vicinity of the Earth in 2006–2009 are presented. The results are obtained by analyzing data from the ...PAMELA experiment aboard the Resurs DK-1 satellite. High-precision detection instruments provided an opportunity to identify GCR deuterons and measure their spectrum in the energy interval of 90–650MeV/nucleon. Spectra averaged over six-month intervals from the summer of 2006 to the summer of 2009 (the solar activity minimum) are presented. The influence of solar modulation on the observed spectrum is clearly seen in the results.
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.
The PAMELA experiment is being conducted on board the RESURS DK1 satellite, launched into a near-Earth, near-polar orbit with an altitude of 350–610 km and an inclination of 70° on June 15, 2006. The ...apparatus comprises a magnetic spectrometer, an electromagnetic calorimeter (16
X
0
), a time-of-flight system, a neutron detector, an anticoincidence system, and a shower tail scintillator. It allows measurements of electron and positron fluxes in cosmic rays over a wide energy range of ∼100 MeV to several hundreds of GeVs. In this work, we present data on the electron and positron energy spectra in primary cosmic rays, obtained between June 2006 and December 2008.
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 existence of trapped antiprotons in the Earth’s inner radiation belt has been theoretically predicted, but not observed. We present a procedure for antiproton selection and the observation ...results from the PAMELA space experiment measurements. The PAMELA magnetic spectrometer ensures reliable identification of particles and charge signs, value determination, and energy measurement, thus enabling us to experimentally establish the existence of antiprotons trapped in the Earth’s inner radiation belt.
The generally accepted theory explaining the observed cosmological baryon asymmetry involves mechanisms of baryosynthesis that generate asymmetry in an initially baryon symmetric Universe. Due to the ...possible inhomogeneous spatial nature of such mechanisms, antimatter domains could arise in the Universe. This hypothesis can be tested by the direct measurement of fluxes of antinuclei in cosmic rays. Searching for antihelium nuclei is therefore among the objectives of the PAMELA experiment. We analyzed data from August 2006 to December 2009 and obtained a preliminary value for the upper limit of the antihelium/helium flux ratio that could lead to some restrictions on the existing theoretical models of the production and propagation of antimatter in the Galaxy.
Magnetospheric and solar physics observations with the PAMELA experiment Casolino, M.; Adriani, O.; Ambriola, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2008, Volume:
588, Issue:
1-2
Journal Article
Peer reviewed
PAMELA is a satellite-borne experiment designed to make long duration measurements of the cosmic radiation in Low Earth Orbit. It is devoted to the detection of the cosmic-ray spectra in the ...100MeV–300GeV range with primary scientific goal the measurement of antiproton and positron spectra over the largest energy range ever achieved. Other tasks include the search for antinuclei with unprecedented sensitivity and the measurement of the light nuclear component of cosmic rays. In addition, PAMELA can investigate phenomena connected with solar and Earth physics. The apparatus consists of: a Time of Flight system, a magnetic spectrometer, an electromagnetic imaging calorimeter, a shower tail catcher scintillator, a neutron detector and an anticoincidence system. In this work we present some measurements of galactic, secondary and trapped particles performed in the first months of operation.
The north-south asymmetry for cosmic-ray particles was measured with one instrument of the PAMELA satellite-borne experiment in the period June 2006–May 2009. The analysis has been performed by two ...independent methods: by comparing the count rates in regions with identical geomagnetic conditions and by comparing the experimental distribution of particle directions with the simulated distribution that would be in the case of an isotropic particle flux. The dependences of the asymmetry on energy release in the PAMELA calorimeter and on time have been constructed. The asymmetry (
N
n
−
N
s
)/(
N
n
+
N
s
) is 0.06 ± 0.004 at the threshold energy release in the calorimeter and gradually decreases with increasing energy release. The observed effect is shown to be produced by electrons in the energy range 10–100 GeV.
Several methods of reconstructing a shower axis and methods of searching for the starting point of the shower are presented. They were developed for “thin“ sampling position-sensitive calorimeters. ...For this purpose we used a Monte Carlo simulation of the interaction of electrons and protons with the silicon-tungsten calorimeter of the PAMELA satellite-borne experiment. After some adaptation, these methods could be applied for different types of calorimeters.
