Multiscaling of galactic cosmic ray flux

Multiscaling analysis of the differential flux dissipation rate of galactic cosmic rays (carbon nuclei) is performed in the energy ranges 56.3-73.4 MeV/nucleon and 183.1-198.7 MeV/nucleon, using the data collected by the ACE/CRIS spacecraft instrument for the year 2000. The analysis reveals strong (turbulencelike) intermittency of the flux dissipation rate for short-term intervals: 1-30 h. It is also found that the type of intermittency can be different in different energy ranges.     

On the structure of galactic cosmic ray intensity during its long-term variations

The structure of GCR intensity and its changes during the solar magnetic cycle are analyzed by numerically solving its transport equation. We propose a research method that allows us to use the intermediate results from numerical calculations, to resolve the intensity of galactic cosmic rays into components caused by sunspot and magnetic solar cycles, and to monitor the changes in energy in different parts of the heliosphere and different phases of the cycle. A method for dividing intensity into its components associated with the main physical processes determining the modulation of galactic cosmic rays is also proposed.     

Validation of the galactic cosmic ray and geomagnetic transmission models

A very high-momentum resolution particle spectrometer called the Alpha Magnetic Spectrometer (AMS) was flown in the payload bay of the Space Shuttle in a 51.65 degrees x 380-km orbit during the last solar minimum. This spectrometer has provided the first high statistics data set for galactic cosmic radiation protons, and helium, as well as limited spectral data on carbon and oxygen nuclei in the International Space Station orbit. First measurements of the albedo protons at this inclination were also made. Because of the high-momentum resolution and high statistics, the data can be separated as a function of magnetic latitude. A related investigation, the balloon borne experiment with a superconducting solenoid spectrometer (BESS), has been flown from Lynn Lake, Canada and has also provided excellent high-resolution data on protons and helium. These two data sets have been used here to study the validity of two galactic cosmic ray models and the geomagnetic transmission function developed from the 1990 geomagnetic reference field model. The predictions of both the CREME96 and NASA/JSC models are in good agreement with the AMS data. The shape of the AMS measured albedo proton spectrum, up to 2 GeV, is in excellent agreement with the previous balloon and satellite observations. A new LIS spectrum was developed that is consistent with both previous and new BESS 3He observations. Because the astronaut radiation exposures onboard ISS will be highest around the time of the solar minimum, these AMS measurements and these models provide important benchmarks for future radiation studies. AMS-02 slated for launch in September 2003, will provide even better momentum resolution and higher statistics data.     

Detecting galactic cosmic ray transuranium nuclei in olivine crystals from meteorites

Results from the experimental search for and identification of tracks from the superheavy and transuranium nuclei of galactic cosmic rays in pallacite olivine crystals, conducted as part of project OLIMPIA [1], are presented. To date, 170 crystals from Marjalahti and Eagle Station pallacites have been processed and 6800 tracks corresponding to nuclei with charges Z > 55 have been found; 45 of these are from nuclei with charges of 88 < Z < 92 and three super-long ones were produced by nuclei with Z > 105. The charge of one of these nuclei is estimated in the first approximation as Z = 119(+10,?6). Our data confirm the hypothesis of islands of stability for natural trans-Fermi nuclei.     

Modulation of galactic cosmic ray intensities by coronal mass ejections into interplanetary space

The data on the measurements of the intensities of galactic cosmic rays with proton energies greater than 30 MeV are compared with the data on the solar wind and interplanetary magnetic field measured on board the Vega-1 and Vega-2 automated interplanetary stations. Modulation structures with characteristic shapes and durations, namely quasi-symmetric (“bays”) short-term Forbush decreases of intensity, are revealed. It is shown that these Forbush decreases were recorded due to the stations flying through coronal mass-ejection regions. Original Russian Text ? E.A. Chuchkov, V.I. Tulupov, V.P. Okhlopkov, G.P. Lyubimov, 2009, published in Vestnik Moskovskogo Universiteta. Fizika, 2009, No. 3, pp. 90–93.     

Ultra-high energy cosmic ray correlations with active galactic nuclei in the world dataset

The Pierre Auger collaboration have recently put forward the hypothesis that the arrival directions of the highest energy cosmic rays correlate with the subset of local active galactic nuclei (AGNs). We perform a blind test of AGN hypothesis using publicly available event sets collected by Yakutsk, AGASA, and HiRes experiments. The consistency of the procedure requires the event energies to be normalized towards the common energy scale. The number of correlating events in resulting data-set is 3 of 21 which is consistent with expected random background.     

Attenuation of cosmic ray heavy nuclei fluxes in the upper atmosphere by fragmentation

Two plastic stacks containing cellulose nitrate as detector material were flown several times with balloons at 40 g cm^?2 for a total time of 25 hours. From the tracks of 920 heavy nuclei the vertical intensities of the particles of four charge groups (6 ? Z ? 9, 10 ? Z ? 14, 15 ? Z ? 19, 20 ? Z ? 28) have been derived for atmospheric depths from 40 – 100 g cm^?2. Combining these intensities with other results obtained with emulsions and in counter measurements, the fragmentation probabilities in air have been determined by comparison with the primary spectra.     

Spectrum of long-term cosmic ray variations during the sunspot minimum in 2009

A method for determining the long-term spectrum of cosmic ray (CR) variations from observations with different ground-based (neutron monitors) and near-earth (stratosphere and satellite) detectors was presented in our previous works. In this paper, muon telescope data (Nagoya) are added, expanding the analyzed energy range and allowing us to determine the rigidity spectrum for 1974–2011. The data from the above devices for these years can be used jointly. The rigidity spectrum for the sunspot minimum of the 24th cycle was studied and compared with the CR intensity for the sunspot minima of other cycles. The reasons for abnormally high CR density during the minimum of the 24th cycle and other features of this period are discussed.     

雷暴电场对宇宙射线次级粒子μ 子的影响研究

西藏羊八井宇宙射线观测站的中子监测器主要探测宇宙射线次级粒子中能量在500 MeV—20 GeV的核子成分和少量的负μ子成分. 本文分析了2008—2010年观测站附近发生的62次雷暴期间中子监测器和大气平均电场仪的同步观测资料, 发现27次雷暴期间中子监测器计数率发生明显变化, 显著性S>5σ, 其中13次变化显著, 显著性S>10σ . 显著性S>10σ的13次个例信号变化百分比与地面电场场强幅值之间存在大体一致的变化趋势, 而显著性在5σ <S<10σ之间的14次个例信号变化百分比与地面电场场强幅值之间不存在相似的变化趋势. 较强雷暴当顶时中子监测器计数率变化一般不明显, 而中子监测器计数率变化明显的个例则多发生于雷暴云不当顶, 但探测器仍处于雷暴云下部正电荷层的控制范围之内时, 或者当顶雷暴处于形成或消散阶段. Dorman等把雷暴期间中子监测器计数率的变化归因于雷暴云内电场对宇宙射线次级粒子μ子的作用, 并建立了雷暴期间中子监测器计数率变化与雷暴地面电场相关联的理论. 本文分析发现雷暴期间羊八井中子监测器计数率变化与地面电场场强之间相关性较小或者没有相关性, 不支持Dorman的理论.     

Induction mechanism of cosmic ray production and kinks in the cosmic ray spectrum

Two kinks are observed in the energy spectrum of galactic cosmic rays. It is shown that the entire spectrum can be described, to a good approximation, by a single formula obtained on the basis of the hypothesis that the particles are produced and accelerated in plasma pinches by an induction mechanism under the assumption that three hierarchical groups of currents are present—interstellar, galactic, and metagalactic. Pis’ma Zh. éksp. Teor. Fiz. 64, No. 4, 225–230 (25 August 1996)     

Model of cosmic ray generation

It is shown that the two bends observed in the cosmic ray energy spectrum can be well approximated by equations derived by assuming that cosmic rays can be generated and accelerated in plasma pinches. Zh. éksp. Teor. Fiz. 111, 385–403 (February 1997)     

Cosmic ray diffusion from the galactic spiral arms,iron meteorites,and a possible climatic connection

We construct a Galactic cosmic ray (CR) diffusion model. The CR flux reaching the Solar System should periodically increase each crossing of a Galactic spiral arm. We confirm this prediction in the CR exposure age record of iron meteorites. We find that although the geological evidence for the occurrence of iceage epochs in the past eon is not unequivocal, it appears to have a nontrivial correlation with the spiral arm crossings-agreeing in period and phase.     

宇宙射线和α放射线的地质作用

对采集到的矿物样品结合理论计算结果进行了详细分析.阐明了矿物样品上的菱形腐蚀坑,可能是宇宙射线粒子和天然放射线中的α粒子与矿物晶格碰撞后,在晶格中留下的损伤经过地层中腐蚀性液体长期腐蚀扩大形成的.讨论了这些腐蚀坑对地质作用的影响.指出这些射线对地质作用的影响,应当是地质作用研究中不可忽视的因素.     

Stationary cosmic jets as accelerators of ultrarelativistic cosmic ray particles

A model of a cosmic jet working in the mode of a magnetohydrodynamic nozzle and unipolar inductor is considered. It is shown that the “solid-state” rotation of screw magnetic field lines leads to acceleration of small fractions of plasma particles up to ultrarelativistic energies with the spectrum dq/d? ～ ? ^?n , the exponent n being close to the experimental value.     

Identification of the primary cosmic ray

The nature of the primary particle giving rise to an atmospheric shower may be, to some extent, inferred from the observable properties: longitudinal profile (especially position of the maximum of the number of charged particles) or shape at ground level (lateral distribution, curvature and thickness of the shower front, muonic component). Distinguishing different nuclei cannot be performed unambiguously on a single shower, because of the random fluctuations in the first steps of the cascade; however, it is possible to study the composition of the incident flux on a statistical basis: showers from heavier nuclei have a faster development, and contain more muons. The uncertainties on the hadronic interactions at the highest energies limit the reliability of the identification. Other primaries, if they exist, could be easier to distinguish. Photons would give a slower development than protons, especially at highest energies, and a very reduced muonic component; neutrinos would be characterized by deep interactions in the atmosphere, or even within the Earth, giving almost horizontal showers with a large electromagnetic component, clearly different from the muonic tail of showers induced in the upper atmosphere by nuclei. Such ‘exotic’ primaries have not yet been observed. To cite this article: P. Billoir, P. Sommers, C. R. Physique 5 (2004).     

On the characteristics of solar activity and galactic cosmic ray intensity at the solar cycle maximum and inflection points

The correlation between the characteristics (sunspot area and galactic cosmic ray intensity) at inflection points and at the solar cycle maximum is discussed. Probable characteristics in the forthcoming maximum of cycle 24 are considered.