458 research outputs found
On the influence of the heliomagnetospheric periphery on the galactic cosmic rays
The suggestion is substantiated that the periphery of the heliomagnetosphere, the region in which properties depend on both solar wind and interstellar space parameters, plays a much more important role in the solar modulation of galactic cosmic rays than previously believed
Solar cosmic ray bursts and solar neutrino fluxes
The neutrino flux detected in the C1-Ar experiment seems to respond to the powerful solar cosmic ray bursts. The ground-based detectors, the balloons and the satellites detect about 50% of the bursts of soalr cosmic ray generated on the Sun's visible side. As a rule, such bursts originate from the Western side of the visible solar disk. Since the solar cosmic ray bursts are in opposite phase withthe 11-year galactic cosmic ray cycle which also seems to be reflected by neutrino experiment. The neutrino generation in the bursts will flatten the possible 11-year behavior of the AR-37 production rate, Q, in the Cl-Ar experiment. The detection of solar-flare-generated gamma-quanta with energies above tens of Mev is indicative of the generation of high-energy particles which in turn may produce neutrinos. Thus, the increased Q during the runs, when the flare-generated high energy gamma-quanta have been registered, may be regarded as additional evidence for neutrino geneation in the solar flare processes
The difference in the energy spectra of galactic cosmic rays at the minima of the 19th and 20th solar activity cycles
The absorption curves of the cosmic ray charged component for solar minima in 1965 and 1975 to 1977 are analyzed on the basis of daily stratospheric measurements in Murmansk, Moscow, Alma-Ata and Mirny (Antarctic). Two distinct features in the energy spectra of galactic cosmic rays are revealed during these periods. At the 20th solar activity minimum there was the additional short range component of cosmic rays. Additional fluxes in the stratosphere at high latitudes caused by this component are probably protons and He nuclei with the energy 100 to 500 MeV/n. The fluxes are estimates as Approx. 300 sq m/s/sr. At the minimum in 1975 to 1977 the proton intensity in the energy range 1 to 15 GeV is 10 to 15% lower than that in the 1965 solar activity minimum
Ion production rates and cross-sections from the atmospheric observations and comparison with the CLOUD experiment results
We present and discuss experimental results obtained from the measurements of cosmic ray fluxes and ion concentrations at different altitudes (from ground level up to 30-35 km) and latitudes (from equator to polar regions) in the Earth's atmosphere. We calculated ionproduction cross-sections and ion production rates from these data sets. The same characteristics are possible to be derived from the CLOUD experimental data using ion concentrations, particle beam intensities, etc. We discuss the methods of estimation of these characteristics in the CLOUD experiment
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Cosmic ray measurements in the atmosphere at several latitudes in October, 2014
Cosmic ray fluxes in the atmosphere were recorded during balloon flights in October 2014 in northern Murmansk region, Apatity (Russia; 67o33’N, 33o24’E), in Antarctica (observatory Mirny; 66o33’S, 93o00’E), in Moscow (Russia; 55o45’N, 37o37’E), in Reading (United King-dom; 51o27’N, 0o 58’W), in Mitzpe-Ramon (Israel; 30o36’N, 34o48’E) and in Zaragoza (Spain; 41o9’N, 0o54’W). Two type of cosmic ray detectors were used, namely, (1) the standard ra-diosonde and its modification constructed at the Lebedev Physical Institute (Moscow, Russia) and (2) the device manufactured at the Reading University (Reading, United Kingdom). We compare and analyze obtained data and focus on the estimation of the cosmic ray latitudinal effect in the atmosphere
Ionization in the atmosphere, comparison between measurements and simulations
A survey of the data on measured particle fluxes and the rate of ionization
in the atmosphere is presented. Measurements as a function of altitude, time
and cut-off rigidity are compared with simulations of particle production from
cosmic rays. The simulations generally give a reasonable representation of the
data. However, some discrepancies are found. The solar modulation of the
particle fluxes is measured and found to be a factor 2.70.8 greater than
that observed for muons alone near sea level.Comment: Accepted for publication in Astrophysics and Space Science
Transactions. Typographical errors fixe
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Results from the CERN pilot CLOUD experiment
During a 4-week run in October–November 2006, a pilot experiment was performed at the CERN Proton Synchrotron in preparation for the Cosmics Leaving OUtdoor Droplets (CLOUD) experiment, whose aim is to study the possible influence of cosmic rays on clouds. The purpose of the pilot experiment was firstly to carry out exploratory measurements of the effect of ionising particle radiation on aerosol formation from trace H2SO4 vapour and secondly to provide technical input for the CLOUD design. A total of 44 nucleation bursts were produced and recorded, with formation rates of particles above the 3 nm detection threshold of between 0.1 and 100 cm−3 s−1, and growth rates between 2 and 37 nm h−1. The corresponding H2SO4 concentrations were typically around 106 cm−3 or less. The experimentally-measured formation rates and H2SO4 concentrations are comparable to those found in the atmosphere, supporting the idea that sulphuric acid is involved in the nucleation of atmospheric aerosols. However, sulphuric acid alone is not able to explain the observed rapid growth rates, which suggests the presence of additional trace vapours in the aerosol chamber, whose identity is unknown. By analysing the charged fraction, a few of the aerosol bursts appear to have a contribution from ion-induced nucleation and ion-ion recombination to form neutral clusters. Some indications were also found for the accelerator beam timing and intensity to influence the aerosol particle formation rate at the highest experimental SO2 concentrations of 6 ppb, although none was found at lower concentrations. Overall, the exploratory measurements provide suggestive evidence for ion-induced nucleation or ion-ion recombination as sources of aerosol particles. However in order to quantify the conditions under which ion processes become significant, improvements are needed in controlling the experimental variables and in the reproducibility of the experiments. Finally, concerning technical aspects, the most important lessons for the CLOUD design include the stringent requirement of internal cleanliness of the aerosol chamber, as well as maintenance of extremely stable temperatures (variations below 0.1 _C)
Two years of flight of the Pamela experiment: results and perspectives
PAMELA is a satellite borne experiment designed to study with great accuracy
cosmic rays of galactic, solar, and trapped nature in a wide energy range
(protons: 80 MeV-700 GeV, electrons 50 MeV-400 GeV). Main objective is the
study of the antimatter component: antiprotons (80 MeV-190 GeV), positrons (50
MeV-270 GeV) and search for antinuclei with a precision of the order of
). The experiment, housed on board the Russian Resurs-DK1 satellite,
was launched on June, 2006 in a orbit with an
inclination of 70 degrees. In this work we describe the scientific objectives
and the performance of PAMELA in its first two years of operation. Data on
protons of trapped, secondary and galactic nature - as well as measurements of
the December 2006 Solar Particle Event - are also provided.Comment: To appear on J. Phys. Soc. Jpn. as part of the proceedings of the
International Workshop on Advances in Cosmic Ray Science March, 17-19, 2008
Waseda University, Shinjuku, Tokyo, Japa
Results from the CERN pilot CLOUD experiment
During a 4-week run in October–November 2006, a pilot experiment was performed at the CERN Proton Synchrotron in preparation for the Cosmics Leaving OUtdoor Droplets (CLOUD) experiment, whose aim is to study the possible influence of cosmic rays on clouds. The purpose of the pilot experiment was firstly to carry out exploratory measurements of the effect of ionising particle radiation on aerosol formation from trace H2SO4 vapour and secondly to provide technical input for the CLOUD design. A total of 44 nucleation bursts were produced and recorded, with formation rates of particles above the 3 nm detection threshold of between 0.1 and 100 cm -3 s -1, and growth rates between 2 and 37 nm h -1. The corresponding H2O concentrations were typically around 106 cm -3 or less. The experimentally-measured formation rates and htwosofour concentrations are comparable to those found in the atmosphere, supporting the idea that sulphuric acid is involved in the nucleation of atmospheric aerosols. However, sulphuric acid alone is not able to explain the observed rapid growth rates, which suggests the presence of additional trace vapours in the aerosol chamber, whose identity is unknown. By analysing the charged fraction, a few of the aerosol bursts appear to have a contribution from ion-induced nucleation and ion-ion recombination to form neutral clusters. Some indications were also found for the accelerator beam timing and intensity to influence the aerosol particle formation rate at the highest experimental SO2 concentrations of 6 ppb, although none was found at lower concentrations. Overall, the exploratory measurements provide suggestive evidence for ion-induced nucleation or ion-ion recombination as sources of aerosol particles. However in order to quantify the conditions under which ion processes become significant, improvements are needed in controlling the experimental variables and in the reproducibility of the experiments. Finally, concerning technical aspects, the most important lessons for the CLOUD design include the stringent requirement of internal cleanliness of the aerosol chamber, as well as maintenance of extremely stable temperatures (variations below 0.1 °C
Long term time variability of cosmic rays and possible relevance to the development of life on Earth
An analysis is made of the manner in which the cosmic ray intensity at Earth
has varied over its existence and its possible relevance to both the origin and
the evolution of life. Much of the analysis relates to the 'high energy' cosmic
rays () and their variability due to the changing
proximity of the solar system to supernova remnants which are generally
believed to be responsible for most cosmic rays up to PeV energies. It is
pointed out that, on a statistical basis, there will have been considerable
variations in the likely 100 My between the Earth's biosphere reaching
reasonable stability and the onset of very elementary life. Interestingly,
there is the increasingly strong possibility that PeV cosmic rays are
responsible for the initiation of terrestrial lightning strokes and the
possibility arises of considerable increases in the frequency of lightnings and
thereby the formation of some of the complex molecules which are the 'building
blocks of life'. Attention is also given to the well known generation of the
oxides of nitrogen by lightning strokes which are poisonous to animal life but
helpful to plant growth; here, too, the violent swings of cosmic ray
intensities may have had relevance to evolutionary changes. A particular
variant of the cosmic ray acceleration model, put forward by us, predicts an
increase in lightning rate in the past and this has been sought in Korean
historical records. Finally, the time dependence of the overall cosmic ray
intensity, which manifests itself mainly at sub-10 GeV energies, has been
examined. The relevance of cosmic rays to the 'global electrical circuit'
points to the importance of this concept.Comment: 18 pages, 5 figures, accepted by 'Surveys in Geophysics
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