| 1. |
- Adriani, O., et al.
(författare)
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Antiprotons in primary cosmic radiation with PAMELA experiment
- 2013
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Ingår i: Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013. - : Sociedade Brasileira de Fisica. - 9788589064293
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Konferensbidrag (refereegranskat)abstract
- The latest measurements of antiprotons spectrum and antiproton-to-proton ratio in primary cosmic rays with PAMELA experiment are presented. They are in good agreement with model of secondary production of antiprotons in Galaxy, but they do not completely rule other sources at the high-energies.
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| 2. |
- Topchiev, N. P., et al.
(författare)
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GAMMA-400 gamma-ray observatory
- 2015
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Ingår i: Proceedings of Science. - : Proceedings of Science (PoS).
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Konferensbidrag (refereegranskat)abstract
- 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 fromGalactic Center, Crab, Vela, Cygnus, Geminga, and other regions will be performed, as well asdiffuse gamma-rayemission,along with measurements of high-energy electron + positron and nuclei fluxes. Furthermore, it will studygamma-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 10 TeV for electrons + positrons, and up to 1015eV 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° to ∼0.01° and energy resolution from 3% to ∼1%; the proton rejection factor is ∼5x105. GAMMA-400 will be installed onboardthe Russian space observatory.
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| 3. |
- Mikhailov, V. V., et al.
(författare)
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Anisotropy analysis of positron data with the PAMELA experiment
- 2013
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Ingår i: Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013. - : Sociedade Brasileira de Fisica. - 9788589064293
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Konferensbidrag (refereegranskat)abstract
- The PAMELA experiment is carried out on board of satellite the Resurs DK1 since 2006 for precision study of cosmic ray antiparticles. The instrument is equipped with magnetic spectrometer, silicon-tungsten imaging electromagnetic calorimeter, neutron detector which give possibility to separate electron and positron over wide energy range up to hundreds GeVs and to measure their incoming direction with accuracy about 2 degree. For each detected particle a space arriving direction was reconstructed using trajectory inside the instrument and the satellite position on the orbit. Backtracking in geomagnetic field was done to obtain initial spatial distribution of particles outside of the Earth magnetosphere. This paper discuss a result of search a possible local sources by anisotropy analysis of positron data.
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| 4. |
- Mikhailov, V. V., et al.
(författare)
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Method of electrons and positrons separations by bremsstrahlung in the PAMELA experiment
- 2013
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Ingår i: Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013. - : Sociedade Brasileira de Fisica. - 9788589064293
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Konferensbidrag (refereegranskat)abstract
- Imaging calorimeter of the PAMELA instrument on board the Resurs DK satellite has high spatial resolution and allows to measure separately electromagnetic showers from electrons and positrons and their bremsstahlung produced in ToF detectors of the instrument. Measuring events with two showers provides proton rejection coefficient more than 104 at energy between 0.5 and 3 GeV. Results of positrons fractions obtained by this method are in agreement with previously published data of the PAMELA experiment at low energy. It confirms in independent way strong positron modulation during period of negative polarity of the Sun magnetic field.
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| 5. |
- Ricciarini, S. B., et al.
(författare)
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PAMELA mission : Heralding a new era in cosmic ray physics
- 2014
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Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2100-014X.
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Konferensbidrag (refereegranskat)abstract
- After seven years of data taking in space, the experiment PAMELA is showing very interesting features in cosmic rays, namely in the fluxes of protons, helium, electrons, that might change our basic vision of the mechanisms of production, acceleration and propagation of cosmic rays in the galaxy. In addition, PAMELA measurements of cosmic antiproton and positron fluxes are setting strong constraints to the nature of Dark Matter. The continuous particle detection is allowing a constant monitoring of the solar activity and detailed study of the solar modulation for a long period, giving important improvements to the comprehension of the heliosphere mechanisms. PAMELA is also measuring the radiation environment around the Earth, and has recently discovered an antiproton radiation belt.
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| 6. |
- Adriani, O., et al.
(författare)
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The gamma-400 space observatory : Status and perspectives
- 2014
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Ingår i: Proceedings of Science. - : Sissa Medialab Srl.
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Konferensbidrag (refereegranskat)abstract
- The present design of the new space observatory GAMMA-400 is presented in this paper. The instrument has been designed for the optimal detection of gamma rays in a broad energy range (from ∼100 MeV up to 3 TeV), with excellent angular and energy resolution. The observatory will also allow precise and high statistic studies of the electron component in the cosmic rays up to the multi TeV region, as well as protons and nuclei spectra up to the knee region. The GAMMA-400 observatory will allow to address a broad range of science topics, like search for signatures of dark matter, studies of Galactic and extragalactic gamma-ray sources, Galactic and extragalactic diffuse emission, gamma-ray bursts and charged cosmic rays acceleration and diffusion mechanism up to the knee.
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| 7. |
- Adriani, O., et al.
(författare)
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The PAMELA Mission : Heralding a new era in precision cosmic ray physics
- 2014
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Ingår i: Physics reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 544:4, s. 323-370
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Forskningsöversikt (refereegranskat)abstract
- On the 15th of June 2006, the PAMELA (Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics) satellite-borne experiment was launched onboard the Russian Resurs-DK1 satellite by a Soyuz rocket from the Baikonur space centre. The satellite was placed in a quasi-polar 70 degrees inclination orbit at an altitude varying between 350 km and 600 km. New results on the antiparticle component of the cosmic radiation were obtained. The positron energy spectrum and positron fraction were measured from 400 MeV up to 200 GeV revealing a positron excess over the predictions of commonly used propagation models. This can be interpreted either as evidence that the propagation models should be revised or in terms of dark matter annihilation or a pulsar contribution. The antiproton spectrum was measured over the energy range from 60 MeV to 350 GeV. The antiproton spectrum is consistent with secondary production and significantly constrains dark matter models. The energy spectra of protons and helium nuclei were measured up to 1.2 TV. The spectral shapes of these two species are different and cannot be described well by a single power law. For the First time the electron spectrum was measured up to 600 GeV complementing the information obtained from the positron data. Nuclear and isotopic composition was obtained with unprecedented precision. The variation of the low energy proton, electron and positron energy spectra was measured from July 2006 until December 2009 accurately sampling the unusual conditions of the most recent solar minimum activity period (2006-2009). Low energy particle spectra were accurately measured also for various solar events that occurred during the PAMELA mission. The Earth's magnetosphere was studied measuring the particle radiation in different regions of the magnetosphere. Energy spectra and composition of sub-cutoff and trapped particles were obtained. For the first time a belt of trapped antiprotons was detected in the South Atlantic Anomaly region. The flux was found to exceed that for galactic cosmic-ray antiprotons by three order of magnitude.
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| 8. |
- Bazilevskaya, G. A., et al.
(författare)
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Solar proton events at the end of the 23rd and start of the 24th solar cycle recorded in the PAMELA experiment
- 2013
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Ingår i: Bulletin of the Russian Academy of Sciences: Physics. - 1062-8738. ; 77:5, s. 493-496
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Tidskriftsartikel (refereegranskat)abstract
- The PAMELA magnetic spectrometer was launched into a near-Earth orbit on board the Resurs-DK1 satellite in June 2006; in December 2006, it recorded the last strong solar high-energy particle event of the 23rd solar cycle. A deficit was thereafter observed in solar energetic particle events because of the lengthy solar activity minimum and the weak evolution of the next (24th) solar cycle. As a result, only a few solar events involving protons with energies of more than 100 MeV were recorded between 2010 and 1012. This work presents the preliminary results from measurements of charged particle fluxes in these events, recorded by the Pamela spectrometer.
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| 9. |
- Giaccari, U., et al.
(författare)
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Anisotropy studies in the cosmic ray proton flux with the PAMELA experiment
- 2013
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Ingår i: Proceedings of the 9th workshop on Science with the New Generation of High Energy Gamma-ray Experiments: From high energy gamma sources to cosmic rays, one century after their discovery. - : Elsevier. ; , s. 123-128
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Konferensbidrag (refereegranskat)abstract
- Using data taken by the Pamela experiment during 5 years of operation we studied the anisotropy in the arrival direction distribution of cosmic ray protons with rigidity above 40 GV. In this survey we used two different and independent techniques to investigate the large and medium anisotropy patterns in the proton spectrum. With both methods the observed distribution of arrival directions is consistent with the isotropic expectation and no significant evidence of strong anisotropies has been observed.
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| 10. |
- Karelin, A. V., et al.
(författare)
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The high energy cosmic ray particle spectra measurements with the PAMELA calorimeter
- 2016
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Ingår i: Nuclear and Particle Physics Proceedings. - : Elsevier. - 2405-6014. ; 273-275, s. 275-281
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Tidskriftsartikel (refereegranskat)abstract
- Up until now there has been limited, contradictive data on the high energy range of the cosmic ray electron-positron, proton and helium spectra. Due to the limitations of the use of a magnetic spectrometer, over 8 years experimental data was processed using information from a sampling electro-magnetic calorimeter, a neutron detector and scintillator detectors. The use of these devices allowed us to successfully obtain the high energy cosmic ray particle spectra measurements. The results of this study clarify previous findings and greaten our understanding of the origin of cosmic rays.
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