Magnetic spectrometer PAMELA was launched onboard a satellite Resurs-DK1 into low-Earth polar orbit with altitude 350-600 km to study cosmic ray antiparticle fluxes in a wide energy range from ∼ 100 ...MeV to hundreds GeV. This paper presents the results of observations of temporal variations of the positron and electron fluxes in the 2006-2015. The ratio of the positron and electron fluxes below 2 GV shows sharp increasing since 2014 due to changing of the polarity of the solar magnetic field.
We present a review of the experimental results obtained by PAMELA in measuring the (p, (p) over bar ) and e(+/-) abundance in cosmic rays. In this context, we discuss the interpretation of the ...observed anomalous positron excess in terms of the annihilation of dark matter particles as well as in terms of standard astrophysical sources. Moreover we show the constraints on dark matter models from (p) over bar data.
The PAMELA space experiment is aimed at precise measurements of the charged light component of the cosmic ray spectrum in the energy range spanning from the sub-GeV region to the TeV region, with a ...particular focus on antimatter. The instrument consists of a magnetic spectrometer, an electromagnetic sampling calorimeter,a time-of-flight system, an anticoincidence shield, a tail-catcher scintillator and a neutron detector. Launched in June 2006 and hosted on the Resurs-DK1 satellite, PAMELA has been taking data for more than eight years, providing scientific results with unprecedented statistics and a continuous monitoring of the sun activity and the heliosphere.
The PAMELA detector was launched on June 15th of 2006 on board the Russian Resurs-DK1 satellite and during ten years of continuous data-taking it has observed very interesting features in cosmic ...rays, especially in the fluxes of protons, helium and electrons. Moreover, PAMELA measurements of cosmic antiproton and positron fluxes and positron-to-all-electron ratio have set strong constraints to the nature of Dark Matter. Measurements of boron, carbon, lithium and beryllium (together with the isotopic fraction) have also shed new light on the elemental composition of the cosmic radiation. Search for signatures of more exotic processes (such as the ones involving Strange Quark Matter) has also been pursued. Furthermore, over the years the instrument has allowed a constant monitoring of the solar activity and a prolonged study of the solar modulation, improving the comprehension of the heliosphere mechanisms. PAMELA has also measured the radiation environment around the Earth, and detected for the first time the presence of an antiproton radiation belt surrounding our planet. In this highlight paper PAMELA main results will be reviewed.
The PAMELA space experiment is providing first direct observations of Solar Energetic Particles (SEPs) with energies from about 80 MeV to several GeV in near-Earth orbit, bridging the low energy ...measurements by other spacecrafts and the Ground Level Enhancement (GLE) data by the worldwide network of neutron monitors. Its unique observational capabilities include the possibility of measuring the flux angular distribution and thus investigating possible anisotropies associated to SEP events. The analysis is supported by an accurate back-tracing simulation based on a realistic description of the Earth's magnetosphere, which is exploited to estimate the SEP energy spectra as a function of the asymptotic direction of arrival with respect to the Interplanetary Magnetic Field (IMF). In this work we report the results for the May 17, 2012 event.
The PAMELA space experiment Menn, W.; Adriani, O.; Barbarino, G.C. ...
Advances in space research,
01/2013, Letnik:
51, Številka:
2
Journal Article
Recenzirano
Odprti dostop
On the 15th of June 2006, the PAMELA satellite-borne experiment was launched from the Baikonur cosmodrome and it has been collecting data since July 2006. The apparatus is comprised of a ...time-of-flight system, a silicon-microstrip magnetic spectrometer, a silicon-tungsten electromagnetic calorimeter, an anticoincidence system, a shower tail counter scintillator and a neutron detector. The combination of these devices allows precision studies of the charged cosmic radiation to be conducted over a wide energy range (100MeV to 100’sGeV) with high statistics. The primary scientific goal is the measurement of the antiproton and positron energy spectra in order to search for exotic sources, such as dark matter particle annihilations. PAMELA is also searching for primordial antinuclei (anti-helium), and testing cosmic-ray propagation models through precise measurements of the antiparticle energy spectrum and precision studies of light nuclei and their isotopes. Moreover, PAMELA is investigating phenomena connected with solar and earth physics. After 4years of operation in flight, PAMELA is now delivering coherent results about spectra and chemical composition of the charged cosmic radiation, allowing scenarios of production and propagation of cosmic rays to be fully established and understood.
The results from searching for solar neutrons with energies lower than 100 MeV from solar flares in the period 2006–2014, based on an analysis of the flight data of the PAMELA international space ...experiment, are presented. The PAMELA neutron detector, based on
3
He counters with an area of 0.18 m
2
, reveals a solar neutron flux at a level of more than ∼300 m
−2
s
−1
. Solar neutrons with energies lower than ∼100 MeV are likely to be found in 7 of 14 flares between 2006 and 2014.
Measurements of secondary-electron and secondary-positron fluxes below the geomagnetic cutoff in near-Earth space were performed by means of the PAMELA magnetic spectrometer installed on board the ...Resurs-DK1 satellite launched on June 15, 2006, in an elliptical orbit of inclination 70° and altitude 350 to 600 km. This spectrometer permits measuring the fluxes of electrons and positrons over a wide energy range, as well as determining their spatial distributions to a precision of about 2°. A calculation of particle trajectories in the geomagnetic field makes it possible to separate electrons and positrons originating from cosmic-ray interactions in the Earth’s magnetosphere. The spatial distributions of quasitrapped, trapped, and short-lived albedo positrons and electrons of energy above 70 MeV in the radiation belt were analyzed. The ratio of the electron-to-positron fluxes and the energy spectra of the electrons and positrons in question are indicative of different productionmechanisms for stably trapped and quasitrapped secondary particles.
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 region ...(altitudes between 350 km and 600 km). Latitudinal dependences of the spectra are analyzed in detail. The results were obtained from July until November 2006 onboard the Resurs‐DK satellite by the PAMELA spectrometer, a general purpose cosmic ray detector system built around a permanent magnet spectrometer and a silicon‐tungsten calorimeter.
On the 15th of June 2006, the PAMELA satellite-borne experiment was launched from the Baikonur cosmodrome and it has been collecting data since July 2006. The apparatus comprises a time-of-flight ...system, a silicon-microstrip magnetic spectrometer, a silicon-tungsten electromagnetic calorimeter, an anti-coincidence system, a shower tail counter scintillator and a neutron detector. The scientific objectives addressed by the mission are the measurement of the antiprotons and positrons spectra in cosmic rays, the hunt for antinuclei as well as the determination of light nuclei fluxes from hydrogen to oxygen in a wide energy range and with very high statistics. In this paper the identification capability for light nuclei isotopes (especially lithium and beryllium) using multiple dE/dx measurements in the calorimeter and first results of the isotopic ratio will be presented.
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