WorldWideScience

Sample records for galactic cosmic-ray particles

  1. Atmospheric data over a solar cycle: no connection between galactic cosmic rays and new particle formation

    Directory of Open Access Journals (Sweden)

    M. Kulmala

    2010-02-01

    Full Text Available Aerosol particles affect the Earth's radiative balance by directly scattering and absorbing solar radiation and, indirectly, through their activation into cloud droplets. Both effects are known with considerable uncertainty only, and translate into even bigger uncertainties in future climate predictions. More than a decade ago, variations in galactic cosmic rays were suggested to closely correlate with variations in atmospheric cloud cover and therefore constitute a driving force behind aerosol-cloud-climate interactions. Later, the enhancement of atmospheric aerosol particle formation by ions generated from cosmic rays was proposed as a physical mechanism explaining this correlation. Here, we report unique observations on atmospheric aerosol formation based on measurements at the SMEAR II station, Finland, over a solar cycle (years 1996–2008 that shed new light on these presumed relationships. Our analysis shows that none of the quantities related to aerosol formation correlates with the cosmic ray-induced ionisation intensity (CRII. We also examined the contribution of ions to new particle formation on the basis of novel ground-based and airborne observations. A consistent result is that ion-induced formation contributes typically significantly less than 10% to the number of new particles, which would explain the missing correlation between CRII and aerosol formation. Our main conclusion is that galactic cosmic rays appear to play a minor role for atmospheric aerosol formation events, and so for the connected aerosol-climate effects as well.

  2. Galactic cosmic ray iron composition

    International Nuclear Information System (INIS)

    Scherzer, R.; Enge, W.; Beaujean, R.

    1980-11-01

    We have studied the isotopic compostition of galactic cosmic ray iron in the energy interval 500-750 MeV/nucleon with a visual track detector system consisting of nuclear emulsion and cellulose-nitrate platic. Stopping iron nuclei were identified from ionization - range measurements in the two detector parts. Cone lengths were measured in the plastic sheets and the residual ranges of the particles were measured in plastic and in emulsion. We have determined the mass of 17 iron nuclei with an uncertainty of about 0.3 amu. The isotopic composition at the detector level was found to be 52 Fe: 53 Fe: 54 Fe: 55 Fe: 56 Fe: 57 Fe: 58 Fe = 0:1: 4:3:8:1:0. These numbers are not in conflict with the assumption that the isotopic composition of cosmic ray iron at the source is similar to the solar system composition. (author)

  3. Does electromagnetic radiation accelerate galactic cosmic rays

    Science.gov (United States)

    Eichler, D.

    1977-01-01

    The 'reactor' theories of Tsytovich and collaborators (1973) of cosmic-ray acceleration by electromagnetic radiation are examined in the context of galactic cosmic rays. It is shown that any isotropic synchrotron or Compton reactors with reasonable astrophysical parameters can yield particles with a maximum relativistic factor of only about 10,000. If they are to produce particles with higher relativistic factors, the losses due to inverse Compton scattering of the electromagnetic radiation in them outweigh the acceleration, and this violates the assumptions of the theory. This is a critical restriction in the context of galactic cosmic rays, which have a power-law spectrum extending up to a relativistic factor of 1 million.

  4. Geneva University: Particle Acceleration in supernova remnants and its implications for the origin of galactic cosmic rays

    CERN Multimedia

    Université de Genève

    2012-01-01

    GENEVA UNIVERSITY École de physique Département de physique nucléaire et corspusculaire 24, quai Ernest-Ansermet 1211 Genève 4 Tél.: (022) 379 62 73 Fax: (022) 379 69 92 Wednesday 28 March 2012 SEMINAIRE DE PHYSIQUE CORPUSCULAIRE 11h15 - Science III, Auditoire 1S081 Particle Acceleration in supernova remnants and its implications for the origin of galactic cosmic rays Prof. Pasquale BLASI INAF, Arcetri Observatory, Firenze The process of cosmic ray energization in supernova remnant shocks is described by the theory of non linear diffusive shock acceleration (NLDSA). Such theory is able to describe the acceleration itself, the dynamical reaction of accelerated particles on the shock, and the crucial phenomenon of the magnetic field amplification, the very key to generate high energy cosmic rays. I will illustrate the basic aspects of this theoretical framework, as well as its successes and problems. I will then discuss the observations, in X-rays an...

  5. Galactic cosmic rays and tropical ozone asymmetries

    International Nuclear Information System (INIS)

    Kilifarska, Natalya; Bakhmutov, Volodymyr; Melnyk, Galyna

    2017-01-01

    Lower stratospheric ozone O_3 is of special interest to climatic studies due to its direct influence on the tropopause temperature, and correspondingly on Earth’s radiation balance. By reason of the suppressed dissociation of molecular oxygen by solar UV radiation and the long life span of the lower stratospheric O_3 , its temporal variability is usually attributed to atmospheric circulation. Here we report about latitudinal-longitudinal differences in a centennial evolution of the tropical O_3 at 70 hPa. These asymmetries are hardly explicable within the concept of the ozone’s dynamical control alone. Analysis of ozone, energetic particles and the geomagnetic records from the last 111 years has revealed that they all evolve synchronously with time. This coherence motivates us to propose a mechanism explaining the geomagnetic and galactic cosmic ray influence on the near tropopause O_3 , allowing for an understanding of its spatial-temporal variability during the past century. Key words: galactic cosmic rays, asymmetries of tropical ozone distribution, geomagnetic filed

  6. Spatial analysis of galactic cosmic ray particles in low earth orbit/near equator orbit using SPENVIS

    International Nuclear Information System (INIS)

    Suparta, W; Zulkeple, S K

    2014-01-01

    The space environment has grown intensively harmful to spacecraft and astronauts. Galactic cosmic rays (GCRs) are one of the radiation sources that composed of high energetic particles originated from space and capable of damaging electronic systems through single event upset (SEU) process. In this paper, we analyzed GCR fluxes at different altitudes by using Space Environment Information System (SPENVIS) software and the results are compared to determine their intensities with respect to distance in the Earth's orbit. The altitudes are set at low earth orbit (400 km and 685 km), medium earth orbit (19,100 km and 20,200 km) and high earth orbit (35,793 km and 1,000,000 km). Then, within Low Earth Orbit (LEO) near the equator (NEqO), we used altitude of 685 km to compare GCRs with the intensities of solar particles and trapped particles in the radiation belt to determine the significance of GCRs in the orbit itself.

  7. Gamma ray astronomy and the origin of galactic cosmic rays

    International Nuclear Information System (INIS)

    Gabici, Stefano

    2011-01-01

    Diffusive shock acceleration operating at expanding supernova remnant shells is by far the most popular model for the origin of galactic cosmic rays. Despite the general consensus received by the model, an unambiguous and conclusive proof of the supernova remnant hypothesis is still missing. In this context, the recent developments in gamma ray astronomy provide us with precious insights into the problem of the origin of galactic cosmic rays, since production of gamma rays is expected both during the acceleration of cosmic rays at supernova remnant shocks and during their subsequent propagation in the interstellar medium. In particular, the recent detection of a number of supernova remnants at TeV energies nicely fits with the model, but it still does not constitute a conclusive proof of it, mainly due to the difficulty of disentangling the hadronic and leptonic contributions to the observed gamma ray emission. The main goal of my research is to search for an unambiguous and conclusive observational test for proving (or disproving) the idea that supernova remnants are the sources of galactic cosmic rays with energies up to (at least) the cosmic ray knee. Our present comprehension of the mechanisms of particle acceleration at shocks and of the propagation of cosmic rays in turbulent magnetic fields encourages beliefs that such a conclusive test might come from future observations of supernova remnants and of the Galaxy in the almost unexplored domain of multi-TeV gamma rays. (author)

  8. Transition from galactic to extra-galactic cosmic rays

    International Nuclear Information System (INIS)

    Aloisio, Roberto

    2006-01-01

    In this paper we review the main features of the observed Cosmic Rays spectrum in the energy range 10 17 eV to 10 20 eV. We present a theoretical model that explains the main observed features of the spectrum, namely the second Knee and Dip, and implies a transition from Galactic to Extra-Galactic cosmic rays at energy E ≅ 10 18 eV, with a proton dominated Extra-Galactic spectrum

  9. Solar modulation of galactic cosmic rays: techniques and applications

    International Nuclear Information System (INIS)

    Perko, J.S.

    1984-01-01

    This thesis covers four topics in the theory of interplanetary cosmic-ray propagation: the first part involves the time-dependent, spherically-symmetric, solar modulation of galactic cosmic rays. A numerical technique was introduced for the solution of this problem. A model for the solar cycle variation in cosmic-ray intensity illustrated this method using enhanced particle scattering regions. The second section contains an attempt to explain recent observations which show that cosmic-ray electrons are returning to higher intensities, characteristic of solar minimum, faster than cosmic-ray protons of about the same energy, the reverse of the previous eleven-year cycle. The third section involves the solar modulation of galactic antiprotons. Using a steady-state, spherically-symmetric, numerical modulation code, a solution that reasonably fits the observed 1980 galactic proton spectrum at 1 AU implied that the modulation used for the data interpretation has been significantly underestimated. The final section contains a spherically-symmetric steady-state calculation of the effects of a strong termination shock in the heliosphere. In the end, high-energy particles cooling down in the upstream solar wind overwhelmed any accelerated low-energy particles

  10. The propagation of galactic cosmic rays

    International Nuclear Information System (INIS)

    Hall, A.N.

    1981-01-01

    Large scale (approximately 15 pc) turbulence in the interstellar medium (ISM) causes the firehose and mirror instabilities to occur. These produce small scale (approximately 10 -7 pc) magnetic irregularities, which scatter cosmic rays. We use pulsar scintillation data, and a model of the origin of these scintillations, to construct a slab model of the turbulent ISM. Then we find the amplitudes and wavelengths of the magnetic irregularities that arise, and we calculate the coefficients for the diffusion of cosmic rays along the interstellar magnetic fields. We incorporate this diffusion into our model of the turbulent ISM, and show that it can account naturally for both the lifetime of low energy cosmic rays, and the variation of their mean pathlength with energy. Our model has no galactic halo, and contains no scattering by Alfven waves. (author)

  11. Particle spectra and mass composition in the ultra-high energy region in the framework of the Galactic origin of cosmic rays

    Directory of Open Access Journals (Sweden)

    Lagutin A.A.

    2017-01-01

    Full Text Available The possibility for a self-consistent description of all the basic features of the observed cosmic ray spectra and primary composition variations in the energy range of 1015 ÷ 1020 eV within the Galactic origin scenario is examined. We assume the existence of Galactic sources that accelerate particles up to ∼ 3 · 1018Z eV and take into account a highly inhomogeneous (fractal-like distribution of matter and magnetic fields in the Galaxy that leads to extremely large free paths of particles (“Lévy flights”, along with an overwhelming contribution to the cosmic ray fluxes observed above ∼1018 eV from particles reaching the Solar System without scattering. Our scenario was refined on the basis of recent experimental results on primary mass composition. Model predictions, which could be verified with the improved high-precision measurements in the nearest future are discussed.

  12. Cosmic ray injection spectrum at the galactic sources

    Science.gov (United States)

    Lagutin, Anatoly; Tyumentsev, Alexander; Volkov, Nikolay

    The spectra of cosmic rays measured at Earth are different from their source spectra. A key to understanding this difference, being crucial for solving the problem of cosmic-ray origin, is the determination of how cosmic-ray (CR) particles propagate through the turbulent interstellar medium (ISM). If the medium is a quasi-homogeneous the propagation process can be described by a normal diffusion model. However, during a last few decades many evidences, both from theory and observations, of the existence of multiscale structures in the Galaxy have been found. Filaments, shells, clouds are entities widely spread in the ISM. In such a highly non-homogeneous (fractal-like) ISM the normal diffusion model certainly is not kept valid. Generalization of this model leads to what is known as "anomalous diffusion". The main goal of the report is to retrieve the cosmic ray injection spectrum at the galactic sources in the framework of the anomalous diffusion (AD) model. The anomaly in this model results from large free paths ("Levy flights") of particles between galactic inhomogeneities. In order to evaluate the CR spectrum at the sources, we carried out new calculation of the CR spectra at Earth. AD equation in terms of fractional derivatives have been used to describe CR propagation from the nearby (r≤1 kpc) young (t≤ 1 Myr) and multiple old distant (r > 1 kpc) sources. The assessment of the key model parameters have been based on the results of the particles diffusion in the cosmic and laboratory plasma. We show that in the framework of the anomalous diffusion model the locally observed basic features of the cosmic rays (difference between spectral exponents of proton, He and other nuclei, "knee" problem, positron to electron ratio) can be explained if the injection spectrum at the main galactic sources of cosmic rays has spectral exponent p˜ 2.85. The authors acknowledge support from The Russian Foundation for Basic Research grant No. 14-02-31524.

  13. Photon losses in cosmic ray acceleration in active galactic nuclei

    International Nuclear Information System (INIS)

    Colgate, S.A.

    1984-01-01

    The usual assumption of the acceleration of ultrahigh energy cosmic rays, greater than or equal to 10 18 eV in quasars, Seyfert galaxies, and other active galactic nuclei is challenged on the basis of the photon interactions with the accelerated nucleons. This is similar to the effect of the black body radiation on particles > 10 20 eV for times of the age of the universe except that the photon spectrum is harder and the energy density greater by approx. = 10 13 . Hence, a single traversal, radial or circumferential, of radiation whose energy density is no greater than the emitted flux will damp an ultrahigh energy cosmic ray 10 20 eV by greater than 10 4 times its energy. Hence, it is unlikely that any reasonable configuration of acceleration can avoid disastrous photon energy loss. A different site for ultrahigh energy cosmic ray acceleration must be found

  14. Acceleration of galactic cosmic rays in shock waves

    International Nuclear Information System (INIS)

    Lagage, P.O.

    1981-06-01

    The old problem of the origin of cosmic rays has triggered off fresh interest owing to the discovery of a new model which enables a lot of energy to be transferred to a small number of particles on the one hand and the discovery of the coronal environment in which this transfer occurs, on the other. In this paper, interest is taken in the galactic cosmic rays and an endeavour is made to find out if the model can reveal the existence of cosmic rays over a wide energy range. The existence of an energy break, predicted by the model, was recognized fairly early but, in the literature, it varies from 30 GeV ro 10 6 GeV according to the authors. A study has been made of the two main causes of an energy break: the sphericity of the shock and the life time of the shock wave [fr

  15. Dark matter and galactic cosmic rays

    International Nuclear Information System (INIS)

    Taillet, R.

    2010-12-01

    Dark matter is one of the major problems encountered by modern cosmology and astrophysics, resisting the efforts of both theoreticians and experimentalists. The problem itself is easy to state: many indirect astrophysical measurements indicate that the mass contained in the Universe seems to be dominated by a new type of matter which has never been directly seen yet, this is why it is called dark matter. This hypothesis of dark matter being made of new particles is of great interest for particle physicists, whose theories provide many candidates: dark matter is one of the major topics of astro-particle physics. This work focuses on searching dark matter in the form of new particles, more precisely to indirect detection, i.e. the search of particles produced by dark matter annihilation rather than dark matter particles themselves. In this framework, I will present the studies I have been doing in the field of cosmic rays physics (particularly cosmic ray sources), in several collaborations. In particular, the study of the antimatter component of cosmic rays can give relevant information about dark matter. The last chapter is dedicated to my teaching activities

  16. Impact of Cosmic-Ray Transport on Galactic Winds

    Science.gov (United States)

    Farber, R.; Ruszkowski, M.; Yang, H.-Y. K.; Zweibel, E. G.

    2018-04-01

    The role of cosmic rays generated by supernovae and young stars has very recently begun to receive significant attention in studies of galaxy formation and evolution due to the realization that cosmic rays can efficiently accelerate galactic winds. Microscopic cosmic-ray transport processes are fundamental for determining the efficiency of cosmic-ray wind driving. Previous studies modeled cosmic-ray transport either via a constant diffusion coefficient or via streaming proportional to the Alfvén speed. However, in predominantly cold, neutral gas, cosmic rays can propagate faster than in the ionized medium, and the effective transport can be substantially larger; i.e., cosmic rays can decouple from the gas. We perform three-dimensional magnetohydrodynamical simulations of patches of galactic disks including the effects of cosmic rays. Our simulations include the decoupling of cosmic rays in the cold, neutral interstellar medium. We find that, compared to the ordinary diffusive cosmic-ray transport case, accounting for the decoupling leads to significantly different wind properties, such as the gas density and temperature, significantly broader spatial distribution of cosmic rays, and higher wind speed. These results have implications for X-ray, γ-ray, and radio emission, and for the magnetization and pollution of the circumgalactic medium by cosmic rays.

  17. Propagation of Galactic Cosmic Rays and Dark Matter indirect Detection

    International Nuclear Information System (INIS)

    Delahaye, Timur

    2010-07-01

    This thesis is dedicated to the study of propagation of cosmic electrons and positrons in the Milky Way and to the indirect detection of dark matter. The existence of dark matter is a hypothesis considered as reasonable from the point of view of cosmology, astrophysics and even particle physics. Nevertheless its detection still eludes us and it is not possible to verify this hypothesis by other means than gravitational one. A possible way to detect dark matter is to look for its annihilation or decay products among Galactic cosmic rays. During the last three years, data concerning cosmic ray electrons and positrons have been accumulated and have reached a remarkable precision. Such a precision requires from us to refine the theoretical models and to quantify the errors. This thesis addresses the study of all the sources of uncertainties affecting predictions of cosmic electrons and positron fluxes, primary and secondary, classical or from exotic origin. The greatest care has been dedicated to the sources and the propagation in the Galactic halo. Moreover a study of gamma and radio emissions associated to these cosmic rays is presented, again with the will of sizing uncertainties. Finally a status of the research for detection of annihilation or decay of Galactic dark matter is presented. (author)

  18. Cosmic ray acceleration by large scale galactic shocks

    International Nuclear Information System (INIS)

    Cesarsky, C.J.; Lagage, P.O.

    1987-01-01

    The mechanism of diffusive shock acceleration may account for the existence of galactic cosmic rays detailed application to stellar wind shocks and especially to supernova shocks have been developed. Existing models can usually deal with the energetics or the spectral slope, but the observed energy range of cosmic rays is not explained. Therefore it seems worthwhile to examine the effect that large scale, long-lived galactic shocks may have on galactic cosmic rays, in the frame of the diffusive shock acceleration mechanism. Large scale fast shocks can only be expected to exist in the galactic halo. We consider three situations where they may arise: expansion of a supernova shock in the halo, galactic wind, galactic infall; and discuss the possible existence of these shocks and their role in accelerating cosmic rays

  19. Supernova Remnants as the Sources of Galactic Cosmic Rays

    NARCIS (Netherlands)

    Vink, J.

    2013-01-01

    The origin of cosmic rays holds still manymysteries hundred years after they were first discovered. Supernova remnants have for long been the most likely sources of Galactic cosmic rays. I discuss here some recent evidence that suggests that supernova remnants can indeed efficiently accelerate

  20. Heavy Ion Testing at the Galactic Cosmic Ray Energy Peak

    Science.gov (United States)

    Pellish, Jonathan A.; Xapsos, M. A.; LaBel, K. A.; Marshall, P. W.; Heidel, D. F.; Rodbell, K. P.; Hakey, M. C.; Dodd, P. E.; Shaneyfelt, M. R.; Schwank, J. R.; hide

    2009-01-01

    A 1 GeV/u Fe-56 Ion beam allows for true 90 deg. tilt irradiations of various microelectronic components and reveals relevant upset trends for an abundant element at the galactic cosmic ray (GCR) flux-energy peak.

  1. The end of the galactic cosmic ray spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Stanev, Todor [Bartol Research Institute, Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States)

    2007-03-15

    We discuss the region of transition between galactic and extragalactic cosmic rays. The exact shapes and compositions of these two components contains information about important parameters of powerful astrophysical sources and the conditions in extragalactic space as well as for the cosmological evolution of the sources of high energy cosmic rays. Several types of experimental data, including the exact shape of the ultrahigh energy cosmic rays, their chemical composition and their anisotropy, and the fluxes of cosmogenic neutrinos have to be included in the solution of this problem.

  2. The transition from galactic to extragalactic cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Stanev, Todor [Bartol Research Institute, Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States)

    2007-06-15

    We discuss the region of transition between galactic and extragalactic cosmic rays. The exact shapes and compositions of these two components contain information about important parameters of powerful astrophysical sources and the conditions in extragalactic space. Several types of experimental data, including the exact shape of the ultrahigh energy cosmic rays, their chemical composition and their anisotropy, and the fluxes of cosmogenic neutrinos have to be included in the solution of this problem.

  3. Markov Stochastic Technique to Determine Galactic Cosmic Ray ...

    Indian Academy of Sciences (India)

    A new numerical model of particle propagation in the Galaxy has been developed, which allows the study of cosmic-ray production and propagation in 2D. The model has been used to solve cosmic ray diffusive transport equation with a complete network of nuclear interactions using the time backward Markov stochastic ...

  4. Role of Turbulent Damping in Cosmic Ray Galactic Winds

    Science.gov (United States)

    Holguin, Francisco; Ruszkowski, Mateusz; Lazarian, Alex; Yang, H. Y. Karen

    2018-06-01

    Large-scale galactic winds driven by stellar feedback are one phenomenon that influences the dynamical and chemical evolution of a galaxy, pushing and redistributing material throughout the interstellar medium (ISM) and galactic halo. A detailed understanding of the exact physical mechanisms responsible for these winds is lacking. Non-thermal feedback from galactic cosmic rays (CR), high-energy charged particles accelerated in supernovae and young stars, can impact the efficiency in accelerating the wind. In the self-confinement model, CR stream along magnetic field lines at the Alfven speed due to scattering off self-excited Aflv{é}n waves. However, magneto-hydrodynamic (MHD) turbulence stirred up by stellar feedback dissipates these confining waves, allowing CR to be super Aflvenic. Previous simulations relying on a simplified model of transport have shown that super-Alfv{é}nic streaming of CRs can launch a stronger wind. We perform three-dimensional MHD simulations of a section of a galactic disk, including CR streaming dependent on the local environment, using a realistic model of turbulent dissipation of Alfven waves presented in Lazarian (2016). In this implementation, the CR streaming speed can be super Alfv{é}nic depending on local conditions. We compare results for Alfv{é}nic and locally determined streaming, and find that gas/CR distributions and instantaneous mass loading factor of the wind are different depending on the level of turbulence.Lazarian, A. “Damping of Alfven waves by turbulence and its consequences: from cosmic-ray streaming to launching winds.” ApJ. Vol. 833, Num. 2. (2016).

  5. Energy spectrum of galactic cosmic ray modulation and dependence of modulation parameters on distance

    International Nuclear Information System (INIS)

    Erkhov, V.I.; Kolomeets, E.V.; Likhoded, V.A.; Sevast'yanov, V.N.; Stekol'nikov, N.V.

    1981-01-01

    The paper presents the results of numerical calculation of galactic cosmic ray modulation by solar wind. Calculations were carried out on the basis of diffusion model taking into account convection and adiabatic loss of particles in interplanetary space. Both isotropic and anisotropic models were used in calculations. Modulation coefficient was calculated using the data on intensity of neutron component of cosmic rays and primary cosmic rays in the stratosphere for the period 1958-1979. The form of modulation function was determined. Obtained results allow to determine the size of modulation region and dependence of solar wind speed and diffusion coefficient on distance

  6. High-Energy Cosmic Ray Self-Confinement Close to Extra-Galactic Sources.

    Science.gov (United States)

    Blasi, Pasquale; Amato, Elena; D'Angelo, Marta

    2015-09-18

    The ultrahigh-energy cosmic rays observed on the Earth are most likely accelerated in extra-Galactic sources. For the typical luminosities invoked for such sources, the electric current associated to the flux of cosmic rays that leave them is large. The associated plasma instabilities create magnetic fluctuations that can efficiently scatter particles. We argue that this phenomenon forces cosmic rays to be self-confined in the source proximity for energies Esources for energies Esource luminosity in units of 10^{44} erg/s.

  7. Cosmic Ray Origin: Lessons from Ultra-High-Energy Cosmic Rays and the Galactic/Extragalactic Transition

    Energy Technology Data Exchange (ETDEWEB)

    Parizot, Etienne

    2014-11-15

    We examine the question of the origin of the Galactic cosmic-rays (GCRs) in the light of the data available at the highest energy end of the spectrum. We argue that the data of the Pierre Auger Observatory and of the KASCADE-Grande experiment suggest that the transition between the Galactic and the extragalactic components takes place at the energy of the ankle in the all-particle cosmic-ray spectrum, and at an energy of the order of 10{sup 17} eV for protons. Such a high energy for Galactic protons appears difficult to reconcile with the general view that GCRs are accelerated by the standard diffusive shock acceleration process at the forward shock of individual supernova remnants (SNRs). We also review various difficulties of the standard SNR-GCR connection, related to the evolution of the light element abundances and to significant isotopic anomalies. We point out that most of the power injected by the supernovæ in the Galaxy is actually released inside superbubbles, which may thus play an important role in the origin of cosmic-rays, and could solve some persistent problems of the standard SNR-GCR scenario in a rather natural way.

  8. Anomalous Galactic Cosmic Rays in the Framework of AMS-02

    Energy Technology Data Exchange (ETDEWEB)

    Khiali, Behrouz [National Central University (NCU), ChungLi, Tao Yuan, 32054, Taiwan (China); Haino, Sadakazu; Feng, Jie, E-mail: behrouz.khiali@cern.ch [Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan (China)

    2017-02-01

    The cosmic-ray (CR) energy spectra of protons and helium nuclei, which are the most abundant components of cosmic radiation, exhibit a remarkable hardening at energies above 100 GeV/nucleon. Recent data from AMS-02 confirm this feature with a higher significance. These data challenge the current models of CR acceleration in Galactic sources and propagation in the Galaxy. Here, we explain the observed break in the spectra of protons and helium nuclei in light of recent advances in CR diffusion theories in turbulent astrophysical sources as being a result of a transition between different CR diffusion regimes. We reconstruct the observed CR spectra using the fact that a transition from normal diffusion to superdiffusion changes the efficiency of particle acceleration and causes the change in the spectral index. We find that calculated proton and helium spectra match the data very well.

  9. Active Galactic Nuclei: Sources for ultra high energy cosmic rays?

    International Nuclear Information System (INIS)

    Biermann, Peter L.; Becker, Julia K.; Caramete, Laurentiu; Curutiu, Alex; Engel, Ralph; Falcke, Heino; Gergely, Laszlo A.; Isar, P. Gina; Maris, Ioana C.; Meli, Athina; Kampert, Karl-Heinz; Stanev, Todor; Tascau, Oana; Zier, Christian

    2009-01-01

    The origin of ultra high energy cosmic rays promises to lead us to a deeper understanding of the structure of matter. This is possible through the study of particle collisions at center-of-mass energies in interactions far larger than anything possible with the Large Hadron Collider, albeit at the substantial cost of no control over the sources and interaction sites. For the extreme energies we have to identify and understand the sources first, before trying to use them as physics laboratories. Here we describe the current stage of this exploration. The most promising contenders as sources are radio galaxies and gamma ray bursts. The sky distribution of observed events yields a hint favoring radio galaxies. Key in this quest are the intergalactic and galactic magnetic fields, whose strength and structure are not yet fully understood. Current data and statistics do not yet allow a final judgement. We outline how we may progress in the near future.

  10. Active Galactic Nuclei: Sources for ultra high energy cosmic rays?

    Energy Technology Data Exchange (ETDEWEB)

    Biermann, Peter L. [MPI for Radioastronomy, Bonn (Germany); Dept. of Phys. and Astron., Univ. of Bonn (Germany); Dept. of Phys. and Astr., Univ. of Alabama, Tuscaloosa, AL (United States); Dept. of Phys., Univ. of Alabama at Huntsville, AL (United States); Inst. Nucl. Phys. FZ, Karlsruhe Inst. of Techn. (KIT) (Germany); Becker, Julia K. [Institution foer Fysik, Goeteborgs Univ. (Sweden); Dept. of Phys., Univ. Dortmund, Dortmund (Germany); Caramete, Laurentiu [MPI for Radioastronomy, Bonn (Germany); Institute for Space Studies, Bucharest (Romania); Curutiu, Alex [MPI for Radioastronomy, Bonn (Germany); Engel, Ralph [Inst. Nucl. Phys. FZ, Karlsruhe Inst. of Techn. (KIT) (Germany); Falcke, Heino [Dept. of Astrophys., IMAP, Radboud Univ., Nijmegen (Netherlands); ASTRON, Dwingeloo (Netherlands); Gergely, Laszlo A. [Dept. Appl. Sci., London South Bank University (United Kingdom); Dept. of Theoret. and Exp. Phys., Univ. of Szeged, Szeged (Hungary); Isar, P. Gina [Inst. Nucl. Phys. FZ, Karlsruhe Inst. of Techn. (KIT) (Germany); Institute for Space Studies, Bucharest (Romania); Maris, Ioana C. [Inst. Nucl. Phys. FZ, Karlsruhe Inst. of Techn. (KIT) (Germany); Meli, Athina [Physik. Inst. Univ. Erlangen-Nuernberg (Germany); Kampert, Karl-Heinz [Phys. Dept., Univ. Wuppertal (Germany); Stanev, Todor [Bartol Research Inst., Univ. of Delaware, Newark, DE (United States); Tascau, Oana [Phys. Dept., Univ. Wuppertal (Germany); Zier, Christian [MPI for Radioastronomy, Bonn (Germany); Raman Res. Inst., Bangalore (India)

    2009-05-15

    The origin of ultra high energy cosmic rays promises to lead us to a deeper understanding of the structure of matter. This is possible through the study of particle collisions at center-of-mass energies in interactions far larger than anything possible with the Large Hadron Collider, albeit at the substantial cost of no control over the sources and interaction sites. For the extreme energies we have to identify and understand the sources first, before trying to use them as physics laboratories. Here we describe the current stage of this exploration. The most promising contenders as sources are radio galaxies and gamma ray bursts. The sky distribution of observed events yields a hint favoring radio galaxies. Key in this quest are the intergalactic and galactic magnetic fields, whose strength and structure are not yet fully understood. Current data and statistics do not yet allow a final judgement. We outline how we may progress in the near future.

  11. Trek and ECCO: Abundance measurements of ultraheavy galactic cosmic rays

    International Nuclear Information System (INIS)

    Westphal, Andrew J.

    2000-01-01

    Using the Trek detector, we have measured the abundances of the heaviest elements (with Z>70) in the galactic cosmic rays with sufficient charge resolution to resolve the even-Z elements. We find that the abundance of Pb compared to Pt is ∼3 times lower than the value expected from the most widely-held class of models of the origin of galactic cosmic ray nuclei, that is, origination in a partially ionized medium with solar-like composition. The low abundance of Pb is, however, consistent with the interstellar gas and dust model of Meyer, Drury and Ellison, and with a source enriched in r-process material, proposed by Binns et al. A high-resolution, high-statistics measurement of the abundances of the individual actinides would distinguish between these models. This is the goal of ECCO, the Extremely Heavy Cosmic-ray Composition Observer, which we plan to deploy on the International Space Station

  12. Origin and propagation of galactic cosmic rays

    Science.gov (United States)

    Cesarsky, Catherine J.; Ormes, Jonathan F.

    1987-01-01

    The study of systematic trends in elemental abundances is important for unfolding the nuclear and/or atomic effects that should govern the shaping of source abundances and in constraining the parameters of cosmic ray acceleration models. In principle, much can be learned about the large-scale distributions of cosmic rays in the galaxy from all-sky gamma ray surveys such as COS-B and SAS-2. Because of the uncertainties in the matter distribution which come from the inability to measure the abundance of molecular hydrogen, the results are somewhat controversial. The leaky-box model accounts for a surprising amount of the data on heavy nuclei. However, a growing body of data indicates that the simple picture may have to be abandoned in favor of more complex models which contain additional parameters. Future experiments on the Spacelab and space station will hopefully be made of the spectra of individual nuclei at high energy. Antiprotons must be studied in the background free environment above the atmosphere with much higher reliability and presion to obtain spectral information.

  13. Ultrahigh energy cosmic rays and new particle physics

    CERN Document Server

    Kachelriess, M.

    2001-02-28

    The current status of the ultrahigh energy cosmic ray (UHE CR) enigma and several proposed solutions involving particle physics beyond the standard model are discussed. Emphasis is given to top--down models, and as a main example, supermassive dark matter as galactic source for UHE CR and the status of its experimental signatures (galactic anisotropy, chemical composition and clustering) is reviewed. Then different approaches to calculate fragmentation spectra of supermassive particles are discussed. Finally, it is argued that UHE neutrinos cannot be - neither directly or indirectly - responsible for the observed vertical air showers.

  14. Identifying Galactic Cosmic Ray Origins With Super-TIGER

    Science.gov (United States)

    deNolfo, Georgia; Binns, W. R.; Israel, M. H.; Christian, E. R.; Mitchell, J. W.; Hams, T.; Link, J. T.; Sasaki, M.; Labrador, A. W.; Mewaldt, R. A.; hide

    2009-01-01

    Super-TIGER (Super Trans-Iron Galactic Element Recorder) is a new long-duration balloon-borne instrument designed to test and clarify an emerging model of cosmic-ray origins and models for atomic processes by which nuclei are selected for acceleration. A sensitive test of the origin of cosmic rays is the measurement of ultra heavy elemental abundances (Z > or equal 30). Super-TIGER is a large-area (5 sq m) instrument designed to measure the elements in the interval 30 TIGER builds on the heritage of the smaller TIGER, which produced the first well-resolved measurements of elemental abundances of the elements Ga-31, Ge-32, and Se-34. We present the Super-TIGER design, schedule, and progress to date, and discuss the relevance of UH measurements to cosmic-ray origins.

  15. Measurements of the isotopic composition of galactic cosmic rays

    International Nuclear Information System (INIS)

    Herrstroem, N.Y.

    1985-01-01

    The galactic cosmic-ray boron and carbon isotopic composition has been measured. The boron measurement is the first ever made in nuclear emulsion. The carbon measurement has substantially improved the statistical assuracy in the determination of the 13 C abundance as compared to an earlier measurement using the same technique. Mass-spectra of cosmic-ray carbon and oxygen in different zenith angle intervals have been compared with calculated spectra. The method makes it possible to study experimentally the atmospheric influence on the primary cosmic-ray isotopic composition. Photometric measurements on fragments from oxygen-induced interactions in nuclear emulsion have been made. Accurate charge assignments have been made on all heavy fragments which has made it possible to study the interaction exclusively event-by-event. Measurements on the isotopic composition of primary cosmic-ray neom have been made. The data are from the Danish-French instrument on the HEAO-3 satellite. The rigidity dependent filtering of the cosmic rays by the Earth's magnetic field has been used. The energy dependence of the 22 Ne/ 20 Ne-ratio and its astrophysical implications are discussed. (Author)

  16. Exploring Ultra-Heavy Cosmic Rays with the Trans-Iron Galactic Element Recorder (TIGER)

    Science.gov (United States)

    Link, Jason; Supertiger Collaboration

    2017-01-01

    Elements heavier than iron are primarily synthesized by neutron capture. These elements can be accelerated as cosmic-rays and measuring their abundances at Earth can yield information about galactic cosmic-rays' sources, the acceleration processes and the composition of the universe beyond the boundaries of our solar system. The Trans-Iron Galactic Element Recorder (TIGER) and its larger successor SuperTIGER was designed to measure the abundance of these ultra-heavy cosmic rays between Z=10 and Z=60. These detectors utilize scintillators with a wavelength shifter bar and PMT readout system as well as aerogel and acrylic Cherenkov detectors to identify the charge and energy of a particle and utilize a scintillating fiber hodoscope to provide trajectory information. In this talk I will review the results from this highly successful program, give the status for the next SuperTIGER flight planned for a December 2017 launch from Antarctica, and discuss the future direction of the program.

  17. Flux and anisotropy of galactic cosmic rays: beyond homogeneous models

    International Nuclear Information System (INIS)

    Bernard, Guilhem

    2013-01-01

    In this thesis I study the consequence of non homogeneously distributed cosmic ray sources in the Milky way. The document starts with theoretical and experimental synthesis. Firstly, I will describe the interstellar medium to understand the mechanism of propagation and acceleration of cosmic rays. Then, the detailed study of cosmic rays diffusion on the galactic magnetic field allows to write a commonly used propagation equation. I will recall the Steady-state solutions of this equation, then I will focus on the time dependant solutions with point-like sources. A statistical study is performed in order to estimate the standard deviation of the flux around its mean value. The computation of this standard deviation leads to mathematical divergences. Thus, I will develop statistical tools to bypass this issue. So i will discuss the effect of the granularity of cosmic ray sources. Its impact on cosmic ray spectrum can explain some recent features observed by the experiments CREAM and PAMELA.Besides, this thesis is focused on the study of the anisotropy of cosmic rays. I will recap experimental methods of measurements, and I will show how to connect theoretical calculation from propagation theories to experimental measurements. Then, the influence of the local environment on the anisotropy measurements will be discussed, particularly the effect of a local diffusion coefficient. Then, I will compute anisotropy and its variance in a framework of point-like local sources with the tools developed in the first part. Finally, the possible influence of local sources on the anisotropy is discussed in the light of the last experimental results. (author) [fr

  18. One century of cosmic rays – A particle physicist's view

    Directory of Open Access Journals (Sweden)

    Sutton Christine

    2015-01-01

    Full Text Available Experiments on cosmic rays and the elementary particles share a common history that dates back to the 19th century. Following the discovery of radioactivity in the 1890s, the paths of the two fields intertwined, especially during the decades after the discovery of cosmic rays. Experiments demonstrated that the primary cosmic rays are positively charged particles, while other studies of cosmic rays revealed various new sub-atomic particles, including the first antiparticle. Techniques developed in common led to the birth of neutrino astronomy in 1987 and the first observation of a cosmic γ-ray source by a ground-based cosmic-ray telescope in 1989.

  19. Cosmic-ray electrons and galactic radio emission - a conflict

    International Nuclear Information System (INIS)

    Badhwar, G.D.; Daniel, R.R.; Stephens, S.A.

    1977-01-01

    Reference is made to attempts in the past to deduce information of astrophysical importance from a study of the galactic non-thermal continuum in relation to cosmic ray electrons observed in the neighbourhood of the Earth. Such investigations were carried out using the cosmic ray electron data obtained from a single experiment or by making use of an average spectrum derived from world data, although it was known that the flux values observed by different investigators in any energy band differed by as much as a factor of 4. This has led to conflicting conclusions being drawn from the analysis of data of different observers. The present authors used a different approach for analysing the observational data, based on arguments of internal consistency between each measured electron spectrum and the magnetic field strength and the dimension of the radio-emitting region required to explain the radio observations. Such an approach makes it possible to highlight the inconsistencies associated with some of the electron measurements and permits certain inferences of cosmic ray and astrophysical interest. From the discussion it is concluded that the observed spectral index of the radio continuum in the Galaxy is in conflict with some of the cosmic ray electron measurements; also that the absolute intensities of cosmic ray electrons as measured in some experiments are so low that they cannot be reconciled either with the interstellar magnetic field limits or with the extent of the galactic disk, and it is likely that the field strength derived from Faraday rotation measurements gives only a lower limit to the local magnetic field in the Galaxy. (U.K.)

  20. Isotopes produced by galactic cosmic rays in iron meteorites

    International Nuclear Information System (INIS)

    Birck, J.L.; Allegre, C.J.

    1985-01-01

    The elements Li, Mg, K, Ca, Ti, V, Cr have been investigated in the iron meteorites Grant and Carbo. Their isotopic ratios show clearly the effects of spallation by galactic cosmic rays. Our experimental technique allows us to determine the concentration of spallation products with a precision close to 1 per mil for a number of isotopes. The effects of shielding are clearly evidenced in the calcium data and the exposure ages are calculated by using the 40 K measurements

  1. High Fidelity Measurement of Free Space Solar Particle Event and Galactic Cosmic Ray Environments at Intermediate Energies

    Science.gov (United States)

    Leitgab, M.

    2018-02-01

    A charged particle measurement experiment mounted externally to the Deep Space Gateway is proposed, contributing to improving astronaut radiation exposure management during Solar Particle Events and Extra Vehicular Activities.

  2. Drift effects on the galactic cosmic ray modulation

    Energy Technology Data Exchange (ETDEWEB)

    Laurenza, M.; Storini, M. [INAF/IAPS, Via Fosso del Cavaliere 100, I-00133 Roma (Italy); Vecchio, A. [Istituto Nazionale di Geofisica e Vulcanologia-Sede di Cosenza, I-87036 Rende (CS) (Italy); Carbone, V., E-mail: monica.laurenza@iaps.inaf.it [Dipartimento di Fisica, Università della Calabria, I-87036 Rende (CS) (Italy)

    2014-02-01

    Cosmic ray (CR) modulation is driven by both solar activity and drift effects in the heliosphere, although their role is only qualitatively understood as it is difficult to connect the CR variations to their sources. In order to address this problem, the Empirical Mode Decomposition technique has been applied to the CR intensity, recorded by three neutron monitors at different rigidities (Climax, Rome, and Huancayo-Haleakala (HH)), the sunspot area, as a proxy for solar activity, the heliospheric magnetic field magnitude, directly related to CR propagation, and the tilt angle (TA) of the heliospheric current sheet (HCS), which characterizes drift effects on CRs. A prominent periodicity at ∼six years is detected in all the analyzed CR data sets and it is found to be highly correlated with changes in the HCS inclination at the same timescale. In addition, this variation is found to be responsible for the main features of the CR modulation during periods of low solar activity, such as the flat (peaked) maximum in even (odd) solar cycles. The contribution of the drift effects to the global Galactic CR modulation has been estimated to be between 30% and 35%, depending on the CR particle energy. Nevertheless, the importance of the drift contribution is generally reduced in periods nearing the sunspot maximum. Finally, threshold values of ∼40°, ∼45°, and >55° have been derived for the TA, critical for the CR modulation at the Climax, Rome, and HH rigidity thresholds, respectively.

  3. Galactic cosmic ray-induced radiation dose on terrestrial exoplanets.

    Science.gov (United States)

    Atri, Dimitra; Hariharan, B; Grießmeier, Jean-Mathias

    2013-10-01

    This past decade has seen tremendous advancements in the study of extrasolar planets. Observations are now made with increasing sophistication from both ground- and space-based instruments, and exoplanets are characterized with increasing precision. There is a class of particularly interesting exoplanets that reside in the habitable zone, which is defined as the area around a star where the planet is capable of supporting liquid water on its surface. Planetary systems around M dwarfs are considered to be prime candidates to search for life beyond the Solar System. Such planets are likely to be tidally locked and have close-in habitable zones. Theoretical calculations also suggest that close-in exoplanets are more likely to have weaker planetary magnetic fields, especially in the case of super-Earths. Such exoplanets are subjected to a high flux of galactic cosmic rays (GCRs) due to their weak magnetic moments. GCRs are energetic particles of astrophysical origin that strike the planetary atmosphere and produce secondary particles, including muons, which are highly penetrating. Some of these particles reach the planetary surface and contribute to the radiation dose. Along with the magnetic field, another factor governing the radiation dose is the depth of the planetary atmosphere. The higher the depth of the planetary atmosphere, the lower the flux of secondary particles will be on the surface. If the secondary particles are energetic enough, and their flux is sufficiently high, the radiation from muons can also impact the subsurface regions, such as in the case of Mars. If the radiation dose is too high, the chances of sustaining a long-term biosphere on the planet are very low. We have examined the dependence of the GCR-induced radiation dose on the strength of the planetary magnetic field and its atmospheric depth, and found that the latter is the decisive factor for the protection of a planetary biosphere.

  4. Galactic origin of cosmic rays II

    International Nuclear Information System (INIS)

    Colgate, S.A.

    1981-01-01

    The CR acceleration due to shocks in the ISM depends upon multiple crossings approx. = c/3 v/sub Alfven/ approx. = 10 4 per e-fold energy gain. The up-stream scattering required to produce this barrier is Alfven wave turbulence. When the ratio (CR pressure)/(B 2 /8π) identical = β > 1, the streaming velocity theoretically and observationally becomes >> v/sub Alfven/ and, hence, no effective up-stream barrier is likely to exist. If all ISM shock acceleration is limited to β approx. 10 13 to 10 14 eV. It is usually assumed that the energy dependent escape from the Galaxy E approx. > 10 15 eV produces a steeper spectrum from 10 15 to 10 18 eV. Above this energy SN's in all galaxies fill the meta galaxy with CR's with a flatter slope. Conversely, an external source that attempts to fill the Galaxy from the outside must have a still steeper spectrum ΔGAMMA approx. = -.75 to penetrate the diffusive barrier of our galaxy yet maintain the observed slope. This is unlikely since the energy density at 10 15 eV in the meta galaxy would be between 10 -1 to 10 -2 of CR's in this galaxy or of the order of 10 3 of the energy density of particles and fields in the IGM

  5. The Galactic Center: A Petaelectronvolt Cosmic-ray Acceleration Factory

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Yi-Qing; Tian, Zhen; Wang, Zhen [Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Li, Hai-Jin; Chen, Tian-Lu [Physics Department of the Science School, Tibet University, Lhasa 850000 (China)

    2017-02-20

    The multiteraelectronvolt γ -rays from the galactic center (GC) have a cutoff at tens of teraelectronvolts, whereas the diffuse emission has no such cutoff, which is regarded as an indication of petaelectronvolt proton acceleration by the HESS experiment. It is important to understand the inconsistency and study the possibility that petaelectronvolt cosmic-ray acceleration could account for the apparently contradictory point and diffuse γ -ray spectra. In this work, we propose that the cosmic rays are accelerated up to greater than petaelectronvolts in the GC. The interaction between cosmic rays and molecular clouds is responsible for the multiteraelectronvolt γ -ray emissions from both the point and diffuse sources today. Enhanced by the small volume filling factor (VFF) of the clumpy structure, the absorption of the γ -rays leads to a sharp cutoff spectrum at tens of teraelectronvolts produced in the GC. Away from the GC, the VFF grows, and the absorption enhancement becomes negligible. As a result, the spectra of γ -ray emissions for both point and diffuse sources can be successfully reproduced under such a self-consistent picture. In addition, a “surviving tail” at ∼100 TeV is expected from the point source, which can be observed by future projects CTA and LHAASO. Neutrinos are simultaneously produced during proton-proton (PP) collision. With 5–10 years of observations, the KM3Net experiment will be able to detect the petaelectronvolt source according to our calculation.

  6. Cosmic ray particle dosimetry and trajectory tracing

    International Nuclear Information System (INIS)

    Cruty, M.R.; Benton, E.V.; Turnbill, C.E.; Philpott, D.E.

    1975-01-01

    Five pocket mice (Perognathus longimembris) were flown on Apollo XVII, each with a solid-state (plastic) nuclear track detector implanted beneath its scalp. The subscalp detectors were sensitive to HZE cosmic ray particles with a LET greater than or approximately equal to 0.15 million electron volts per micrometer (MeV/micron). A critical aspect of the dosimetry of the experiment involved tracing individual particle trajectories through each mouse head from particle tracks registered in the individual subscalp detectors, thereby establishing a one-to-one correspondence between a trajectory location in the tissue and the presence or absence of a lesion. The other major aspect was the identification of each registered particle. An average of 16 particles with Z greater than or equal to 6 and 2.2 particles with Z greater than or equal to 20 were found per detector. The track density, 29 tracks/sq cm, when adjusted for detection volume, was in agreement with the photographic emulsion data from an area dosimeter located next to the flight package

  7. Balloon measurement of the isotopic composition of galactic cosmic ray boron, carbon, and nitrogen

    International Nuclear Information System (INIS)

    Zumberge, J.F.

    1981-01-01

    The isotopic compositions of galactic cosmic ray boron, carbon, and nitrogen have been measured at energies near 300 MeV amu -1 , using a balloon-borne instrument at an atmospheric depth of approx. 5 g cm -2 . The calibrations of the detectors comprising the instrument are described. The saturation properties of the cesium iodide scintillators used for measurement of particle energy are studied in the context of analyzing the data for mass. The achieved rms mass resolution varies from approx. 0.3 amu at boron to approx. 0.5 amu at nitrogen, consistent with a theoretical analysis of the contributing factors. A model of galactic propagation and solar modulation is described. Assuming a cosmic ray source composition of solar-like isotopic abundances, the model predicts abundances near earth consistent with the measurements

  8. Can diffusive shock acceleration in supernova remnants account for high-energy galactic cosmic rays?

    International Nuclear Information System (INIS)

    Hillas, A M

    2005-01-01

    Diffusive shock acceleration at the outer front of expanding supernova remnants has provided by far the most popular model for the origin of galactic cosmic rays, and has been the subject of intensive theoretical investigation. But several problems loomed at high energies-how to explain the smooth continuation of the cosmic-ray spectrum far beyond 10 14 eV, the very low level of TeV gamma-ray emission from several supernova remnants, and the very low anisotropy of cosmic rays (seeming to conflict with the short trapping times needed to convert a E -2 source spectrum into the observed E -2.7 spectrum of cosmic rays). However, recent work on the cosmic ray spectrum (especially at KASCADE) strongly indicates that about half of the flux does turn down rather sharply near 3 x 10 15 V rigidity, with a distinct tail extending to just beyond 10 17 V rigidity; whilst a plausible description (Bell and Lucek) of the level of self-generated magnetic fields at the shock fronts of young supernova remnants implies that many SNRs in varying environments might very well generate spectra extending smoothly to just this 'knee' position, and a portion of the exploding red supergiants could extend the spectrum approximately as needed. At low energies, recent progress in relating cosmic ray compositional details to modified shock structure also adds weight to the belief that the model is working on the right lines, converting energy into cosmic rays very efficiently where injection can occur. The low level of TeV gamma-ray flux from many young SNRs is a serious challenge, though it may relate to variations in particle injection efficiency with time. The clear detection of TeV gamma rays from SNRs has now just begun, and predictions of a characteristic curved particle spectrum give a target for new tests by TeV observations. However, the isotropy seriously challenges the assumed cosmic-ray trapping time and hence the shape of the spectrum of particles released from SNRs. There is

  9. The HZE radiation problem. [highly-charged energetic galactic cosmic rays

    Science.gov (United States)

    Schimmerling, Walter

    1990-01-01

    Radiation-exposure limits have yet to be established for missions envisioned in the framework of the Space Exploration Initiative. The radiation threat outside the earth's magnetosphere encompasses protons from solar particle events and the highly charged energetic particles constituting galactic cosmic rays; radiation biology entails careful consideration of the extremely nonuniform patterns of such particles' energy deposition. The ability to project such biological consequences of exposure to energetic particles as carcinogenicity currently involves great uncertainties from: (1) different regions of space; (2) the effects of spacecraft structures; and (3) the dose-effect relationships of single traversals of energetic particles.

  10. Solar Energetic Particles (SEP) and Galactic Cosmic Rays (GCR) as tracers of solar wind conditions near Saturn: Event lists and applications

    Science.gov (United States)

    Roussos, E.; Jackman, C. M.; Thomsen, M. F.; Kurth, W. S.; Badman, S. V.; Paranicas, C.; Kollmann, P.; Krupp, N.; Bučík, R.; Mitchell, D. G.; Krimigis, S. M.; Hamilton, D. C.; Radioti, A.

    2018-01-01

    The lack of an upstream solar wind monitor poses a major challenge to any study that investigates the influence of the solar wind on the configuration and the dynamics of Saturn's magnetosphere. Here we show how Cassini MIMI/LEMMS observations of Solar Energetic Particle (SEP) and Galactic Cosmic Ray (GCR) transients, that are both linked to energetic processes in the heliosphere such us Interplanetary Coronal Mass Ejections (ICMEs) and Corotating Interaction Regions (CIRs), can be used to trace enhanced solar wind conditions at Saturn's distance. SEP protons can be easily distinguished from magnetospheric ions, particularly at the MeV energy range. Many SEPs are also accompanied by strong GCR Forbush Decreases. GCRs are detectable as a low count-rate noise signal in a large number of LEMMS channels. As SEPs and GCRs can easily penetrate into the outer and middle magnetosphere, they can be monitored continuously, even when Cassini is not situated in the solar wind. A survey of the MIMI/LEMMS dataset between 2004 and 2016 resulted in the identification of 46 SEP events. Most events last more than two weeks and have their lowest occurrence rate around the extended solar minimum between 2008 and 2010, suggesting that they are associated to ICMEs rather than CIRs, which are the main source of activity during the declining phase and the minimum of the solar cycle. We also list of 17 time periods ( > 50 days each) where GCRs show a clear solar periodicity ( ∼ 13 or 26 days). The 13-day period that derives from two CIRs per solar rotation dominates over the 26-day period in only one of the 17 cases catalogued. This interval belongs to the second half of 2008 when expansions of Saturn's electron radiation belts were previously reported to show a similar periodicity. That observation not only links the variability of Saturn's electron belts to solar wind processes, but also indicates that the source of the observed periodicity in GCRs may be local. In this case GCR

  11. Galactic cosmic ray simulation at the NASA Space Radiation Laboratory

    Science.gov (United States)

    Norbury, John W.; Schimmerling, Walter; Slaba, Tony C.; Azzam, Edouard I.; Badavi, Francis F.; Baiocco, Giorgio; Benton, Eric; Bindi, Veronica; Blakely, Eleanor A.; Blattnig, Steve R.; Boothman, David A.; Borak, Thomas B.; Britten, Richard A.; Curtis, Stan; Dingfelder, Michael; Durante, Marco; Dynan, William S.; Eisch, Amelia J.; Elgart, S. Robin; Goodhead, Dudley T.; Guida, Peter M.; Heilbronn, Lawrence H.; Hellweg, Christine E.; Huff, Janice L.; Kronenberg, Amy; La Tessa, Chiara; Lowenstein, Derek I.; Miller, Jack; Morita, Takashi; Narici, Livio; Nelson, Gregory A.; Norman, Ryan B.; Ottolenghi, Andrea; Patel, Zarana S.; Reitz, Guenther; Rusek, Adam; Schreurs, Ann-Sofie; Scott-Carnell, Lisa A.; Semones, Edward; Shay, Jerry W.; Shurshakov, Vyacheslav A.; Sihver, Lembit; Simonsen, Lisa C.; Story, Michael D.; Turker, Mitchell S.; Uchihori, Yukio; Williams, Jacqueline; Zeitlin, Cary J.

    2017-01-01

    Most accelerator-based space radiation experiments have been performed with single ion beams at fixed energies. However, the space radiation environment consists of a wide variety of ion species with a continuous range of energies. Due to recent developments in beam switching technology implemented at the NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory (BNL), it is now possible to rapidly switch ion species and energies, allowing for the possibility to more realistically simulate the actual radiation environment found in space. The present paper discusses a variety of issues related to implementation of galactic cosmic ray (GCR) simulation at NSRL, especially for experiments in radiobiology. Advantages and disadvantages of different approaches to developing a GCR simulator are presented. In addition, issues common to both GCR simulation and single beam experiments are compared to issues unique to GCR simulation studies. A set of conclusions is presented as well as a discussion of the technical implementation of GCR simulation. PMID:26948012

  12. Production of NO by galactic cosmic rays and lightning

    International Nuclear Information System (INIS)

    Grant, K.E.; Wuebbles, D.J.

    1987-07-01

    As part of the ongoing development of the LLNL 2-D Stratospheric Transport-Kinetics Model, values for NO production rates due to galactic cosmic rays (GCRs) and lightning have been calculated. With the combined NO production rates from GCRs and lightning included in the LLNL 2-D model, we compared our predicted NO/sub y/ mixing ratios with those from LIMS (Limb Infrared Monitor of the Stratosphere) data and other models. Although our predicted NO/sub y/ mixing ratios are lower than the LIMS data at 16 mb and 30 mb, our values at these pressures are generally higher and in better agreement with LIMS than are the corresponding mixing ratios from other models. Further research is needed on the sensitivity of these results to changes in model transport processes. 12 refs., 1 fig., 5 tabs

  13. High Energy Galactic Cosmic Rays Observed by RUNJOB Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Hareyama, Makoto [Advanced Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555 (Japan)

    2006-03-21

    Galactic cosmic rays (GCRs) from proton to iron with the energy of 10{sup 13} - 10{sup 15} eV were observed by RUssia-Nippon JOint Balloon (RUNJOB) experiments. Each energy spectrum of the primary nuclear components except for helium is in agreement with the results obtained by other observations in the same energy region as the RUNJOB observation within statistical errors, while the intensity of the helium component is nearly half that obtained by the JACEE and the SOKOL observations. The spectrum slopes seem to be almost parallel or become gradually harder as mass becomes heavier. The power indices of the spectra are nearly -2.75 in the energy range of 20-500 TeV/nucleous. These our results support the acceleration mechanism and the propagation process in Galaxy of GCRs depend on its rigidity.

  14. Latest AMS Results on elementary particles in cosmic rays

    Science.gov (United States)

    Kounine, Andrei; AMS Collaboration

    2017-01-01

    AMS-02 is a particle physics detector collecting data on the International Space Station since May 2011. Precision measurements of all elementary charged cosmic ray particles have been performed by AMS using a data sample of 85 billion cosmic ray events collected during the first five years of operations on the Station. The latest AMS results on the fluxes and flux ratios of the elementary cosmic ray particles are presented. They show unique features that require accurate theoretical interpretation as to their origin, be it from dark matter collisions or new astrophysical sources. On behalf of the AMS Collaboration.

  15. Constraints on particle dark matter from cosmic-ray antiprotons

    International Nuclear Information System (INIS)

    Fornengo, N.; Vittino, A.; Maccione, L.

    2014-01-01

    Cosmic-ray antiprotons represent an important channel for dark matter indirect-detection studies. Current measurements of the antiproton flux at the top of the atmosphere and theoretical determinations of the secondary antiproton production in the Galaxy are in good agreement, with no manifest deviation which could point to an exotic contribution in this channel. Therefore, antiprotons can be used as a powerful tool for constraining particle dark matter properties. By using the spectrum of PAMELA data from 50 MV to 180 GV in rigidity, we derive bounds on the dark matter annihilation cross section (or decay rate, for decaying dark matter) for the whole spectrum of dark matter annihilation (decay) channels and under different hypotheses of cosmic-rays transport in the Galaxy and in the heliosphere. For typical models of galactic propagation, the constraints are strong, setting a lower bound on the dark matter mass of a ''thermal'' relic at about 40–80 GeV for hadronic annihilation channels. These bounds are enhanced to about 150 GeV on the dark matter mass, when large cosmic-rays confinement volumes in the Galaxy are considered, and are reduced to 3–4 GeV for annihilation to light quarks (no bound for heavy-quark production) when the confinement volume is small. Bounds for dark matter lighter than few tens of GeV are due to the low energy part of the PAMELA spectrum, an energy region where solar modulation is relevant: to this aim, we have implemented a detailed solution of the transport equation in the heliosphere, which allowed us not only to extend bounds to light dark matter, but also to determine the uncertainty on the constraints arising from solar modulation modelling. Finally, we estimate the impact of soon-to-come AMS-02 data on the antiproton constraints

  16. Structure of irregular galactic magnetic fields determined on the basis of cosmic ray measurements

    International Nuclear Information System (INIS)

    Somogyi, A.

    1975-02-01

    In the paper a method is described to determine the structural composition of random galactic fields on the basis of cosmic ray measurements, down to structures with characteristic length of the order of 0.001 to 1 pc. Assuming the diffusion mean free path of the particles to be independent of particle energy the spectral index of magnetic irregularities is estimated to be -(1.0+-0.5). The linear size of the confinement volume is found to be almost independent of particle energy. (Sz.Z.)

  17. The Revival of Galactic Cosmic-Ray Nucleosynthesis?

    International Nuclear Information System (INIS)

    Fields, B.D.; Olive, K.A.

    1999-01-01

    Because of the roughly linear correlation between Be/H and Fe/H in low-metallicity halo stars, it has been argued that a open-quotes primaryclose quotes component in the nucleosynthesis of Be must be present in addition to the open-quotes secondaryclose quotes component from standard Galactic cosmic-ray nucleosynthesis. In this paper we critically reevaluate the evidence for the primary versus secondary character of Li, Be, and B (LiBeB) evolution, analyzing both the observations and Galactic chemical evolution models. Although it appears that [Be/H] versus [Fe/H] has a logarithmic slope near 1, it is rather the Be-O trend that directly arises from the physics of spallation production. Using new abundances for oxygen in halo stars based on UV OH lines, we find that in Population II stars for which O has been measured, the Be-O slope has a large uncertainty due to systematic effects. Namely, the Be-O logarithmic slope lies in the range 1.3 endash 1.8, rendering it difficult to distinguish from the data between the secondary slope of 2 and the primary slope of 1. The possible difference between the Be-Fe and Be-O slopes is a consequence of the variation in O/Fe versus Fe: recent data suggest that the best-fit O/Fe-Fe slope for Population II is in the range -0.5 to -0.2, rather than zero (i.e., Fe∝O) as is often assumed. In addition to this phenomenological analysis of Be and B evolution, we have also examined the predicted LiBeB, O, and Fe trends in Galactic chemical evolution models that include outflow. Based on our results, it is possible that a good fit to the LiBeB evolution requires only the traditional Galactic cosmic-ray spallation and the (primary) neutrino-process contribution to 11 B. We thus suggest that these two processes might be sufficient to explain 6 Li, Be, and B evolution in the Galaxy, without the need for an additional primary source of Be and B. However, the uncertainties in the data at this time prevent one from reaching a definitive

  18. Th/U/Pu/Cm dating of galactic cosmic rays with the extremely heavy cosmic ray composition observer

    Science.gov (United States)

    Westphal, Andrew J.; Weaver, Benjamin A.; Tarlé, Gregory

    The principal goal of ECCO, the Extremely-heavy Cosmic-ray Composition Observer, is the measurement of the age of heavy galactic cosmic-ray nuclei using the extremely rare actinides (Th, U, Pu, Cm) as clocks. ECCO is one of two cosmic-ray instruments comprising the Heavy Nuclei Explorer (HNX), which was recently selected as one of several missions for Phase A study under NASA's Small class Explorer (SMEX) program. ECCO is based on the flight heritage of Trek, an array of barium-phosphate glass tracketch detectors deployed on the Russian space station Mir from 1991-1995. Using Trek, we measured the abundances of elements with Z > 70 in the galactic cosmic rays (GCRs). Trek consisted of a 1 m 2 array of stacks of individually polished thin BP-1 glass detectors. ECCO will be a much larger instrument, but will achieve both excellent resolution and low cost through use of a novel detector configuration. Here we report the results of recent accelerator tests of the ECCO detectors that verify detector performance. We also show the expected charge and energy resolution of ECCO as a function of energy.

  19. Photon damping in cosmic-ray acceleration in active galactic nuclei

    International Nuclear Information System (INIS)

    Colgate, S.A.

    1983-01-01

    The usual assumption of the acceleration of ultra high energy cosmic rays, greater than or equal to 10 18 eV in quasars, Seyfert galaxies and other active galactic nuclei is challenged on the basis of the photon interactions with the accelerated nucleons. This is similar to the effect of the black body radiation on particles > 10 20 eV for times of the age of the universe except that the photon spectrum is harder and the energy density greater by approx. = 10 15 . Hence, a single traversal, radial or circumferential, of radiation whose energy density is no greater than the emitted flux will damp an ultra high energy. Hence, it is unlikely that any reasonable configuration of acceleration can void disastrous photon energy loss. A different site for ultra high energy cosmic ray acceleration must be found

  20. Galactic Cosmic-Ray Energy Spectra and Composition during the 2009-2010 Solar Minimum Period

    Science.gov (United States)

    Lave, K. A.; Wiedenbeck, Mark E.; Binns, W. R.; Christian, E. R.; Cummings, A. C.; Davis, A. J.; deNolfo, G. A.; Israel, M. H..; Leske, R. A.; Mewaldt, R. A.; hide

    2013-01-01

    We report new measurements of the elemental energy spectra and composition of galactic cosmic rays during the 2009-2010 solar minimum period using observations from the Cosmic Ray Isotope Spectrometer (CRIS) onboard the Advanced Composition Explorer. This period of time exhibited record-setting cosmic-ray intensities and very low levels of solar activity. Results are given for particles with nuclear charge 5 solar minimum and 2001-2003 solar maximum are also given here. For most species, the reported intensities changed by less than approx. 7%, and the relative abundances changed by less than approx. 4%. Compared with the 1997-1998 solar minimum relative abundances, the 2009-2010 abundances differ by less than 2sigma, with a trend of fewer secondary species observed in the more recent time period. The new 2009-2010 data are also compared with results of a simple "leaky-box" galactic transport model combined with a spherically symmetric solar modulation model. We demonstrate that this model is able to give reasonable fits to the energy spectra and the secondary-to-primary ratios B/C and (Sc+Ti+V)/Fe. These results are also shown to be comparable to a GALPROP numerical model that includes the effects of diffusive reacceleration in the interstellar medium.

  1. Nucleosynthesis in Wolf-Rayet stars and galactic cosmic-ray isotopic composition

    International Nuclear Information System (INIS)

    Prantzos, N.

    1984-01-01

    An explanation of the isotopic composition of galactic cosmic rays could provide some clues to the mystery of their origin. It seems now that the strong stellar winds of Wolf-Rayet stars could account for most of the isotopic anomalies that have been observed in cosmic rays. Some results are presented, obtained by detailed nucleosynthesis computations. 25 references

  2. Chemistry of the galactic cosmic ray induced ionosphere of Titan

    Science.gov (United States)

    Molina-Cuberos, G. J.; López-Moreno, J. J.; Rodrigo, R.; Lara, L. M.

    1999-09-01

    Titan's lower ionosphere (from 1 to 400 km) has been studied with a one-dimensional ion-neutral model. In this region of the atmosphere, galactic cosmic rays (GCRs) are the main ionization source. They penetrate to the deeper atmosphere and ionize the neutral constituents of Titan's atmosphere (mainly N2, CH4, Ar, H2, and CO) to produce N2+, N+, Ar+, CH4+, CH3+, CH2+, H2+, H+, and CO+. Fast reactions with the neutrals convert these ions into ions such as CH5+, C2H5+, and N2H+. Different pathways are proposed to obtain the ion and electron densities. The most abundant ions are cluster ions, like CH5+.CH4, HCO+.H2, and HCNH+.C2H4, and long chain hydrocarbon ions. In atmospheres very rich in N2, such as Titan's, ions like H4C7N+ and CH3CNH+ also represent an important contribution to the total positive ion density. Three-body reactions may play an important role in the dense atmosphere of Titan, and special attention is devoted to them. The calculated electron density in the lower atmosphere reaches a peak of ~2150 cm-3 at an altitude of 90 km.

  3. Are there persistent physical atmospheric responses to galactic cosmic rays?

    International Nuclear Information System (INIS)

    Benestad, Rasmus E

    2013-01-01

    Variations in the annual mean of the galactic cosmic ray flux (GCR) are compared with annual variations in the most common meteorological variables: temperature, mean sea-level barometric pressure, and precipitation statistics. A multiple regression analysis was used to explore the potential for a GCR response on timescales longer than a year and to identify ‘fingerprint’ patterns in time and space associated with GCR as well as greenhouse gas (GHG) concentrations and the El Niño–Southern Oscillation (ENSO). The response pattern associated with GCR consisted of a negative temperature anomaly that was limited to parts of eastern Europe, and a weak anomaly in the sea-level pressure (SLP), but coincided with higher pressure over the Norwegian Sea. It had a similarity to the North Atlantic Oscillation (NAO) in the northern hemisphere and a wave train in the southern hemisphere. A set of Monte Carlo simulations nevertheless indicated that the weak amplitude of the global mean temperature response associated with GCR could easily be due to chance (p-value = 0.6), and there has been no trend in the GCR. Hence, there is little empirical evidence that links GCR to the recent global warming. (letter)

  4. Confinement and Isotropization of Galactic Cosmic Rays by Molecular-Cloud Magnetic Mirrors When Turbulent Scattering Is Weak

    International Nuclear Information System (INIS)

    Chandran, Benjamin D. G.

    2000-01-01

    Theoretical studies of magnetohydrodynamic (MHD) turbulence and observations of solar wind fluctuations suggest that MHD turbulence in the interstellar medium is anisotropic at small scales, with smooth variations along the background magnetic field and sharp variations perpendicular to the background field. Turbulence with this anisotropy is inefficient at scattering cosmic rays, and thus the scattering rate ν may be smaller than has been traditionally assumed in diffusion models of Galactic cosmic-ray propagation, at least for cosmic-ray energies E above 1011-1012 eV at which self-confinement is not possible. In this paper, it is shown that Galactic cosmic rays can be effectively confined through magnetic reflection by molecular clouds, even when turbulent scattering is weak. Elmegreen's quasi-fractal model of molecular-cloud structure is used to argue that a typical magnetic field line passes through a molecular cloud complex once every ∼300 pc. Once inside the complex, the field line will in most cases be focused into one or more dense clumps in which the magnetic field can be much stronger than the average field in the intercloud medium (ICM). Cosmic rays following field lines into cloud complexes are most often magnetically reflected back into the ICM, since strong-field regions act as magnetic mirrors. For a broad range of cosmic-ray energies, a cosmic ray initially following some particular field line separates from that field line sufficiently slowly that the cosmic ray can be trapped between neighboring cloud complexes for long periods of time. The suppression of cosmic-ray diffusion due to magnetic trapping is calculated in this paper with the use of phenomenological arguments, asymptotic analysis, and Monte Carlo particle simulations. Formulas for the coefficient of diffusion perpendicular to the Galactic disk are derived for several different parameter regimes within the E-ν plane. In one of these parameter regimes in which scattering is weak, it

  5. The Pierre Auger Observatory scaler mode for the study of solar activity modulation of galactic cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, P.; /Lisbon, LIFEP /Lisbon, IST; Aglietta, M.; /Turin Observ. /Turin U. /INFN, Turin; Ahn, E.J.; /Fermilab; Allard, D.; /APC, Paris; Allekotte, I.; /Centro Atomico Bariloche /Balseiro Inst., San Carlos de Bariloche; Allen, J.; /New York U.; Alvarez Castillo, J.; /Mexico U.; Alvarez-Muniz, J.; /Santiago de Compostela U.; Ambrosio, M.; /Naples U. /INFN, Naples; Aminaei, A.; /Nijmegen U., IMAPP; Anchordoqui, L.; /Wisconsin U., Milwaukee /Lisbon, LIFEP /Lisbon, IST

    2011-01-01

    Since data-taking began in January 2004, the Pierre Auger Observatory has been recording the count rates of low energy secondary cosmic ray particles for the self-calibration of the ground detectors of its surface detector array. After correcting for atmospheric effects, modulations of galactic cosmic rays due to solar activity and transient events are observed. Temporal variations related with the activity of the heliosphere can be determined with high accuracy due to the high total count rates. In this study, the available data are presented together with an analysis focused on the observation of Forbush decreases, where a strong correlation with neutron monitor data is found.

  6. On the age distribution of galactic cosmic rays

    International Nuclear Information System (INIS)

    Owens, A.J.

    1975-01-01

    I consider the general solution for the distribution of ages for primary cosmic rays for a class of steady-state, bounded models of cosmic-ray diffusion in the galaxy. Both one dimensional and three-dimensional models are considered, with point sources and distributed sources. In all models, the age distribution is approximately exponential for ages longer than the average age, although for shorter ages the distribution depends on the details of the model. (orig.) [de

  7. Heliospheric Modulation of Galactic Cosmic Rays; Diurnal Variability Abstract Details

    Science.gov (United States)

    Kalu, D. F.; Okpala, K. C.

    2017-12-01

    We have studied the variability of Cosmic rays flux during solar quiet days at mid and high latitudes in the Northern Hemisphere. By using the five (5) quietest days for each month and the five disturbed days for each month, the monthly mean diurnal variation of cosmic ray anisotropy have been derived for the period 1999-2015, which covers part of cycles 23, and cycle 24. This study seeks to understand the heliospheric contribution to the variation of these Cosmic rays on quietest days, three stations (Inuvik, Moscow, Rome) Neutron Monitors were employed. This study seeks to understand the important features of the high latitude and mid latitude diurnal wave, and how solar and geomagnetic activity may be influencing the wave characteristics. Cosmic ray wave characteristics were obtained by discrete Fourier transform (DFT). The mean, diurnal amplitude, phase and dispersion for each month's diurnal wave were calculated and profiled. There was clear indication that the terrestrial effect on the variability of the monthly mean was more associated with geomagnetic activity rather than rigidity of the cosmic rays. Correlation of the time series of these wave characteristic with solar and geomagnetic activity index showed better association with solar activity.

  8. Measurement of hydrogen and helium isotopes flux in galactic cosmic rays with the PAMELA experiment

    Energy Technology Data Exchange (ETDEWEB)

    Formato, V., E-mail: valerio.formato@ts.infn.it [INFN, Sezione di Trieste, I-34149 Trieste (Italy); University of Trieste, Department of Physics, I-34147 Trieste (Italy); Adriani, O. [University of Florence, Department of Physics, I-50019 Sesto Fiorentino, Florence (Italy); INFN, Sezione di Florence, I-50019 Sesto Fiorentino, Florence (Italy); Barbarino, G.C. [University of Naples “Federico II”, Department of Physics, I-80126 Naples (Italy); INFN, Sezione di Naples, I-80126 Naples (Italy); Bazilevskaya, G.A. [Lebedev Physical Institute, RU-119991, Moscow (Russian Federation); Bellotti, R. [University of Bari, Department of Physics, I-70126 Bari (Italy); INFN, Sezione di Bari, I-70126 Bari (Italy); Boezio, M. [INFN, Sezione di Trieste, I-34149 Trieste (Italy); Bogomolov, E.A. [Ioffe Physical Technical Institute, RU-194021 St. Petersburg (Russian Federation); Bongi, M. [University of Florence, Department of Physics, I-50019 Sesto Fiorentino, Florence (Italy); INFN, Sezione di Florence, I-50019 Sesto Fiorentino, Florence (Italy); Bonvicini, V. [INFN, Sezione di Trieste, I-34149 Trieste (Italy); Bottai, S. [INFN, Sezione di Florence, I-50019 Sesto Fiorentino, Florence (Italy); Bruno, A.; Cafagna, F. [INFN, Sezione di Bari, I-70126 Bari (Italy); Campana, D. [INFN, Sezione di Naples, I-80126 Naples (Italy); Carbone, R. [INFN, Sezione di Trieste, I-34149 Trieste (Italy); Carlson, P. [KTH, Department of Physics, AlbaNova University Centre, SE-10691 Stockholm (Sweden); Oskar Klein Centre for Cosmoparticle Physics (Sweden); Casolino, M. [INFN, Sezione di Rome “Tor Vergata”, I-00133 Rome (Italy); RIKEN, Advanced Science Institute, Wako-shi, Saitama (Japan); Castellini, G. [IFAC, I-50019 Sesto Fiorentino, Florence (Italy); and others

    2014-04-01

    PAMELA is a satellite borne experiment designed to study with great accuracy cosmic rays of galactic, solar, and trapped nature, with particular focus on the antimatter component. The detector consists of a permanent magnet spectrometer core to provide rigidity and charge sign information, a Time-of-Flight system for velocity and charge information, a Silicon–Tungsten calorimeter and a Neutron detector for lepton/hadron identification. The velocity and rigidity information allow the identification of different isotopes for Z=1 and Z=2 particles in the energy range 100 MeV/n to 1 GeV/n. In this work we will present the PAMELA results on the H and He isotope fluxes based on the data collected during the 23rd solar minimum from 2006 to 2007. Such fluxes carry relevant information helpful in constraining parameters in galactic cosmic rays propagation models complementary to those obtained from other secondary to primary measurements such as the boron-to-carbon ratio.

  9. Background to Dark Matter Searches from Galactic Cosmic Rays

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    Just as searches for BSM physics at the LHC necessitate a careful audit of SM backgrounds, the search for signals of dark matter in cosmic rays must contend with production of secondaries like e+ and pbar through cosmic ray propagation in the Galaxy. The theoretical framework for calculating this has however not been directly calibrated at the high energies being explored by AMS-02 and there may be surprises in store. In particular a nearby source where cosmic rays are being accelerated stochastically can naturally generate a e+ fraction rising with energy as is observed. The test of this is the expected correlated rise in other secondary/primary ratios e.g. B/C and pbar/p. Such a nearby cosmic accelerator should also be detectable through the concomitant flux of neutrinos and its discovery would be (nearly!) as exciting as that of dark matter.

  10. Particle and astrophysics aspects of ultrahigh energy cosmic rays

    International Nuclear Information System (INIS)

    Sigl, G.

    2001-01-01

    The origin of cosmic rays is one of the major unresolved astrophysical questions. In particular, the highest energy cosmic rays observed possess macroscopic energies and their origin is likely to be associated with the most energetic processes in the Universe. Their existence triggered a flurry of theoretical explanations ranging from conventional shock acceleration to particle physics beyond the Standard Model and processes taking place at the earliest moments of our Universe. Furthermore, many new experimental activities promise a strong increase of statistics at the highest energies and a combination with γ-ray and neutrino astrophysics will put strong constraints on these theoretical models. Detailed Monte Carlo simulations indicate that charged ultra-high energy cosmic rays can also be used as probes of large scale magnetic fields whose origin may open another window into the very early Universe. We give an overview over this quickly evolving research field. (author)

  11. Particle and astrophysics aspects of ultrahigh energy cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Sigl, G [Institut d' Astrophysique de Paris, Paris (France)

    2001-11-15

    The origin of cosmic rays is one of the major unresolved astrophysical questions. In particular, the highest energy cosmic rays observed possess macroscopic energies and their origin is likely to be associated with the most energetic processes in the Universe. Their existence triggered a flurry of theoretical explanations ranging from conventional shock acceleration to particle physics beyond the Standard Model and processes taking place at the earliest moments of our Universe. Furthermore, many new experimental activities promise a strong increase of statistics at the highest energies and a combination with {gamma}-ray and neutrino astrophysics will put strong constraints on these theoretical models. Detailed Monte Carlo simulations indicate that charged ultra-high energy cosmic rays can also be used as probes of large scale magnetic fields whose origin may open another window into the very early Universe. We give an overview over this quickly evolving research field. (author)

  12. Markov Stochastic Technique to Determine Galactic Cosmic Ray ...

    Indian Academy of Sciences (India)

    has been developed, which allows the study of cosmic-ray production and propagation in ... sive transport equation with a complete network of nuclear interactions using the ... This paper describes a further development of the model to calculate the .... In case of several nuclei the problem is expanded to solve a system of ...

  13. Cellular track model of biological damage to mammalian cell cultures from galactic cosmic rays

    Science.gov (United States)

    Cucinotta, Francis A.; Katz, Robert; Wilson, John W.; Townsend, Lawrence W.; Nealy, John E.; Shinn, Judy L.

    1991-01-01

    The assessment of biological damage from the galactic cosmic rays (GCR) is a current interest for exploratory class space missions where the highly ionizing, high-energy, high-charge ions (HZE) particles are the major concern. The relative biological effectiveness (RBE) values determined by ground-based experiments with HZE particles are well described by a parametric track theory of cell inactivation. Using the track model and a deterministic GCR transport code, the biological damage to mammalian cell cultures is considered for 1 year in free space at solar minimum for typical spacecraft shielding. Included are the effects of projectile and target fragmentation. The RBE values for the GCR spectrum which are fluence-dependent in the track model are found to be more severe than the quality factors identified by the International Commission on Radiological Protection publication 26 and seem to obey a simple scaling law with the duration period in free space.

  14. Cellular track model of biological damage to mammalian cell cultures from galactic cosmic rays

    International Nuclear Information System (INIS)

    Cucinotta, F.A.; Katz, R.; Wilson, J.W.; Townsend, L.W.; Nealy, J.E.; Shinn, J.L.

    1991-02-01

    The assessment of biological damage from the galactic cosmic rays (GCR) is a current interest for exploratory class space missions where the highly ionizing, high-energy, high-charge ions (HZE) particles are the major concern. The relative biological effectiveness (RBE) values determined by ground-based experiments with HZE particles are well described by a parametric track theory of cell inactivation. Using the track model and a deterministic GCR transport code, the biological damage to mammalian cell cultures is considered for 1 year in free space at solar minimum for typical spacecraft shielding. Included are the effects of projectile and target fragmentation. The RBE values for the GCR spectrum which are fluence-dependent in the track model are found to be more severe than the quality factors identified by the International Commission on Radiological Protection publication 26 and seem to obey a simple scaling law with the duration period in free space

  15. Badhwar - O'Neill 2014 Galactic Cosmic Ray Flux Model Description

    Science.gov (United States)

    O'Neill, P. M.; Golge, S.; Slaba, T. C.

    2014-01-01

    The Badhwar-O'Neill (BON) Galactic Cosmic Ray (GCR) model is based on GCR measurements from particle detectors. The model has mainly been used by NASA to certify microelectronic systems and the analysis of radiation health risks to astronauts in space missions. The BON14 model numerically solves the Fokker-Planck differential equation to account for particle transport in the heliosphere due to diffusion, convection, and adiabatic deceleration under the assumption of a spherically symmetric heliosphere. The model also incorporates an empirical time delay function to account for the lag of the solar activity to reach the boundary of the heliosphere. This technical paper describes the most recent improvements in parameter fits to the BON model (BON14). Using a comprehensive measurement database, it is shown that BON14 is significantly improved over the previous version, BON11.

  16. MODELING THE GAMMA-RAY EMISSION IN THE GALACTIC CENTER WITH A FADING COSMIC-RAY ACCELERATOR

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ruo-Yu; Wang, Xiang-Yu; Prosekin, Anton [Max-Planck-Institut für Kernphysik, D-69117 Heidelberg (Germany); Chang, Xiao-Chuan, E-mail: ruoyu@mpi-hd.mpg.de, E-mail: xywang@nju.edu.cn [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China)

    2016-12-20

    Recent HESS observations of the ∼200 pc scale diffuse gamma-ray emission from the central molecular zone (CMZ) suggest the presence of a PeV cosmic-ray accelerator (PeVatron) located in the inner 10 pc region of the Galactic center. Interestingly, the gamma-ray spectrum of the point-like source (HESS J1745-290) in the Galactic center shows a cutoff at ∼10 TeV, implying a cutoff around 100 TeV in the cosmic-ray proton spectrum. Here we propose that the gamma-ray emission from the inner and the outer regions may be explained self-consistently by run-away protons from a single yet fading accelerator. In this model, gamma-rays from the CMZ region are produced by protons injected in the past, while gamma-rays from the inner region are produced by protons injected more recently. We suggest that the blast wave formed in a tidal disruption event (TDE) caused by the supermassive black hole (Sgr A*) could serve as such a fading accelerator. With typical parameters of the TDE blast wave, gamma-ray spectra of both the CMZ region and HESS J1745-290 can be reproduced simultaneously. Meanwhile, we find that the cosmic-ray energy density profile in the CMZ region may also be reproduced in the fading accelerator model when appropriate combinations of the particle injection history and the diffusion coefficient of cosmic rays are adopted.

  17. The problems of cosmic ray particle simulation for the near-Earth orbital and interplanetary flight conditions

    International Nuclear Information System (INIS)

    Nymmik, R.A.

    1999-01-01

    A wide range of the galactic cosmic ray and SEP event flux simulation problems for the near-Earth satellite and manned spacecraft orbits and for the interplanetary mission trajectories are discussed. The models of the galactic cosmic ray and SEP events in the Earth orbit beyond the Earth's magnetosphere are used as a basis. The particle fluxes in the near-Earth orbits should be calculated using the transmission functions. To calculate the functions, the dependences of the cutoff rigidities on the magnetic disturbance level and on magnetic local time have to be known. In the case of space flights towards the Sun and to the boundary of the solar system, particular attention is paid to the changes in the SEP event occurrence frequency and size. The particle flux gradients are applied in this case to galactic cosmic ray fluxes

  18. Features of the galactic magnetic field regarding deflections of ultra-high-energy cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Wirtz, Marcus; Erdmann, Martin; Mueller, Gero; Urban, Martin [III. Physikalisches Institut A, RWTH Aachen University (Germany)

    2016-07-01

    Most recent models of the galactic magnetic field have been derived from Faraday rotation measurements and imply strong deflections even for ultra-high energy cosmic rays. We investigate the characteristics of the different field parametrizations and point out similarities and interesting features. Among them are extragalactic regions which are invisible for an Earth bound observation and the transition from diffuse to ballistic behaviour in the 1 EeV energy regime. Applying this knowledge to a directional analysis, there are indications for deflection patterns by the galactic magnetic field in cosmic ray arrival directions measured by the Pierre Auger Observatory.

  19. Isotopic composition of neon in the galactic cosmic rays: a high resolution measurement

    International Nuclear Information System (INIS)

    Greiner, D.E.; Wiedenbeck, M.E.; Bieser, F.S.; Crawford, H.J.; Heckman, H.H.; Lindstrom, P.J.

    1979-06-01

    A measurement of the isotopic composition of galactic cosmic ray neon in the energy range 70 to 260 MeV/amu has been made using the U.C. Berkeley HKH instrument aboard ISEE-3. A combination of high resolution and good statistical accuracy makes possible a precise determination of the local interplanetary neon composition. We find 22 Ne/ 20 Ne = 0.64 +- 0.07 and 21 Ne/ 20 Ne < 0.30 in local interplanetary space. These ratios, when interpreted in using standard galactic propagation and solar modulation models, yield cosmic ray source abundances which are inconsistent with a solar-like source composition

  20. Diffuse gamma-ray emission from self-confined cosmic rays around Galactic sources

    Science.gov (United States)

    D'Angelo, Marta; Morlino, Giovanni; Amato, Elena; Blasi, Pasquale

    2018-02-01

    The propagation of particles accelerated at supernova remnant shocks and escaping the parent remnants is likely to proceed in a strongly non-linear regime, due to the efficient self-generation of Alfvén waves excited through streaming instability near the sources. Depending on the amount of neutral hydrogen present in the regions around the sites of supernova explosions, cosmic rays may accumulate an appreciable grammage in the same regions and get self-confined for non-negligible times, which in turn results in an enhanced rate of production of secondaries. Here we calculate the contribution to the diffuse gamma-ray background due to the overlap along lines of sight of several of these extended haloes as due to pion production induced by self-confined cosmic rays. We find that if the density of neutrals is low, the haloes can account for a substantial fraction of the diffuse emission observed by Fermi-Large Area Telescope (LAT), depending on the orientation of the line of sight with respect to the direction of the Galactic Centre.

  1. Insights into the Galactic Cosmic-ray Source from the TIGER Experiment

    Science.gov (United States)

    Link, Jason T.; Barbier, L. M.; Binns, W. R.; Christian, E. R.; Cummings, J. R.; Geier, S.; Israel, M. H.; Lodders, K.; Mewaldt,R. A.; Mitchell, J. W.; hide

    2009-01-01

    We report results from 50 days of data accumulated in two Antarctic flights of the Trans-Iron Galactic Element Recorder (TIGER). With a detector system composed of scintillators, Cherenkov detectors, and scintillating optical fibers, TIGER has a geometrical acceptance of 1.7 sq m sr and a charge resolution of 0.23 cu at Iron. TIGER has obtained abundance measurements of some of the rare galactic cosmic rays heavier than iron, including Zn, Ga, Ge, Se, and Sr, as well as the more abundant lighter elements (down to Si). The heavy elements have long been recognized as important probes of the nature of the galactic cosmic-ray source and accelerator. After accounting for fragmentation of cosmic-ray nuclei as they propagate through the Galaxy and the atmosphere above the detector system, the TIGER source abundances are consistent with a source that is a mixture of about 20% ejecta from massive stars and 80% interstellar medium with solar system composition. This result supports a model of cosmic-ray origin in OB associations previously inferred from ACE-CRIS data of more abundant lighter elements. These TIGER data also support a cosmic-ray acceleration model in which elements present in interstellar grains are accelerated preferentially compared with those found in interstellar gas.

  2. Cosmic ray muons and their associated shower particles underwater

    International Nuclear Information System (INIS)

    Anderson, S.N.

    1978-01-01

    The nucleonic contamination of the underwater cosmic ray muon flux is studied as a function of depth. Stacks of Ilford G-5 photographic emulsions were assembled and processed in an underground laboratory (9 hg/cm 2 below sea level). In between the assembly and the development they were exposed, stored in small pressure chambers, at various depths underwater for periods of time up to six months. At each depth approximately 10 cm 3 of emulsion were scanned for stopping particles and nuclear disintegrations. Altogether approximately 2000 stopping muons, 50 stopping mesons, and 200 recoil protons were found and analyzed. Comparison with theories as to how the underground cosmic ray muon beam produces a secondary flux of nuclearly active particles are made. Additionally measurements on the residue flux at 440mwe underground are made. Projected rates from the shallow depth studies are used to analyze the results at large depth. Anomalous particle production is observed at the large depth

  3. Correlation of the highest-energy cosmic rays with the positions of nearby active galactic nuclei

    NARCIS (Netherlands)

    Abraham, J.; Abreu, P.; Aglietta, M.; Aguirre, C.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Alvarez-Muniz, J.; Ambrosio, M.; Anchordoqui, L.; Andringa, S.; Anzalone, A.; Aramo, C.; Argiro, S.; Arisaka, K.; Armengaud, E.; Arneodo, F.; Arqueros, F.; Asch, T.; Asorey, H.; Assis, P.; Atulugama, B. S.; Aublin, J.; Ave, M.; Avila, G.; Baecker, T.; Badagnani, D.; Barbosa, A. F.; Barnhill, D.; Barroso, S. L. C.; Bauleo, P.; Beatty, J. J.; Beau, T.; Becker, B. R.; Becker, K. H.; Bellido, J. A.; BenZvi, S.; Berat, C.; Bergmann, T.; Bernardini, P.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanch-Bigas, O.; Blanco, F.; Blasi, P.; Bleve, C.; Bluemer, H.; Bohacova, M.; Bonifazi, C.; Bonino, R.; Brack, J.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Burton, R. E.; Busca, N. G.; Caballero-Mora, K. S.; Cai, B.; Camin, D. V.; Caramete, L.; Caruso, R.; Carvalho, W.; Castellina, A.; Catalano, O.; Cataldi, G.; Cazon, L.; Cester, R.; Chauvin, J.; Chiavassa, A.; Chinellato, J. A.; Chou, A.; Chye, J.; Clay, R. W.; Colombo, E.; Conceicao, R.; Connolly, B.; Contreras, F.; Coppens, J.; Cordier, A.; Cotti, U.; Coutu, S.; Covault, C. E.; Creusot, A.; Criss, A.; Cronin, J.; Curutiu, A.; Dagoret-Campagne, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Donato, C.; Bg, S. J. de Jong; De La Vega, G.; de Mello, W. J. M.; de Mello Neto, J. R. T.; De Mitri, I.; de Souza, V.; del Peral, L.; Deligny, O.; Della Selva, A.; Delle Fratte, C.; Dembinski, H.; Di Giulio, C.; Diaz, J. C.; Diep, P. N.; Dobrigkeit, C.; D'Olivo, J. C.; Dong, P. N.; Dornic, D.; Dorofeev, A.; dos Anjos, J. C.; Dova, M. T.; D'Urso, D.; Dutan, I.; DuVernois, M. A.; Engel, R.; Epele, L.; Escobar, C. O.; Etchegoyen, A.; Luis, P. Facal San; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferrer, F.; Ferry, S.; Fick, B.; Filevich, A.; Filipcic, A.; Fleck, I.; Fracchiolla, C. E.; Fulgione, W.; Garcia, B.; Gaimez, D. Garcia; Garcia-Pinto, D.; Garrido, X.; Geenen, H.; Gelmini, G.; Gemmeke, H.; Ghia, P. L.; Giller, M.; Glass, H.; Gold, M. S.; Golup, G.; Albarracin, F. Gomez; Berisso, M. Gomez; Herrero, R. Gomez; Goncalves, P.; do Amaral, M. Goncalves; Gonzalez, D.; Gonzalezc, J. G.; Gonzalez, M.; Gora, D.; Gorgi, A.; Gouffon, P.; Grassi, V.; Grillo, A. F.; Grunfeld, C.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Gutierrez, J.; Hague, J. D.; Hamilton, J. C.; Hansen, P.; Harari, D.; Harmsma, S.; Harton, J. L.; Haungs, A.; Hauschildt, T.; Healy, M. D.; Hebbeker, T.; Hebrero, G.; Heck, D.; Hojvat, C.; Holmes, V. C.; Homola, P.; Hoerandel, J.; Horneffer, A.; Horvat, M.; Hrabovsky, M.; Huege, T.; Hussain, M.; Larlori, M.; Insolia, A.; Ionita, F.; Italiano, A.; Kaducak, M.; Kampert, K. H.; Karova, T.; Kegl, B.; Keilhauer, B.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapik, R.; Knapp, J.; Koanga, V. -H.; Krieger, A.; Kroemer, O.; Kuempel, D.; Kunka, N.; Kusenko, A.; La Rosa, G.; Lachaud, C.; Lago, B. L.; Lebrun, D.; LeBrun, P.; Lee, J.; de Oliveira, M. A. Leigui; Lopez, R.; Letessier-Selvon, A.; Leuthold, M.; Lhenry-Yvon, I.; Aguera, A. Lopez; Bahilo, J. Lozano; Garcia, R. Luna; Maccarone, M. C.; Macolino, C.; Maldera, S.; Mancarella, G.; Mancenido, M. E.; Mandatat, D.; Mantsch, P.; Mariazzi, A. G.; Maris, I. C.; Falcon, H. R. Marquez; Martello, D.; Martinez, J.; Bravo, O. Martinez; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurizio, D.; Mazur, P. O.; McCauley, T.; McEwen, M.; McNeil, R. R.; Medina, M. C.; Medina-Tanco, G.; Meli, A.; Melo, D.; Menichetti, E.; Menschikov, A.; Meurer, Chr.; Meyhandan, R.; Micheletti, M. I.; Miele, G.; Miller, W.; Mollerach, S.; Monasor, M.; Ragaigne, D. Monnier; Montanet, F.; Morales, B.; Morello, C.; Moreno, J. C.; Morris, C.; Mostafa, M.; Muller, M. A.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Newman-Holmes, C.; Newton, D.; Nhung, P. T.; Nierstenhoefer, N.; Nitz, D.; Nosek, D.; Nozka, L.; Oehlschlaeger, J.; Ohnuki, T.; Olinto, A.; Olmos-Gilbaja, V. M.; Ortiz, M.; Ortolani, F.; Ostapchenko, S.; Otero, L.; Pacheco, N.; Selmi-Dei, D. Pakk; Palatka, M.; Pallotta, J.; Parente, G.; Parizot, E.; Parlati, S.; Pastor, S.; Patel, M.; Paul, T.; Pavlidou, V.; Payet, K.; Pech, M.; Pekala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Petrera, S.; Petrinca, P.; Petrov, Y.; Pichel, A.; Piegaia, R.; Pierog, T.; Pimenta, M.; Pinto, T.; Pirronello, V.; Pisanti, O.; Platino, M.; Pochon, J.; Privitera, P.; Prouza, M.; Quel, E. J.; Rautenberg, J.; Redondo, A.; Reucroft, S.; Revenu, B.; Rezende, F. A. S.; Ridky, J.; Riggi, S.; Risse, M.; Riviere, C.; Rizi, V.; Roberts, M.; Robledo, C.; Rodriguez, G.; Martino, J. Rodriguez; Rojo, J. Rodriguez; Rodriguez-Cabo, I.; Rodriguez-Frias, M. D.; Ros, G.; Rosado, J.; Roth, M.; Rouille-d'Orfeuil, B.; Roulet, E.; Roverok, A. C.; Salamida, F.; Salazar, H.; Salina, G.; Sanchez, F.; Santander, M.; Santo, C. E.; Santos, E. M.; Sarazin, F.; Sarkar, S.; Sato, R.; Scherini, V.; Schieler, H.; Schmidt, A.; Schmidt, F.; Schmidt, T.; Scholten, O.; Schovanek, P.; Schuessler, F.; Sciutto, S. J.; Scuderi, M.; Segreto, A.; Semikoz, D.; Settimo, M.; Shellard, R. C.; Sidelnik, I.; Siffert, B. B.; Sigl, G.; De Grande, N. Smetniansky; Smialkowski, A.; Smida, R.; Smith, A. G. K.; Smith, B. E.; Snow, G. R.; Sokolsky, P.; Sommers, P.; Sorokin, J.; Spinka, H.; Squartini, R.; Strazzeri, E.; Stutz, A.; Suarez, F.; Suomijarvi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Takahashi, J.; Tamashiro, A.; Tamburro, A.; Tascau, O.; Tcaciuc, R.; Thao, N. T.; Thomas, D.; Ticona, R.; Tiffenberg, J.; Timmermans, C.; Tkaczyk, W.; Peixoto, C. J. Todero; Tome, B.; Tonachini, A.; Torres, I.; Travnicek, P.; Tripathi, A.; Tristram, G.; Tscherniakhovski, D.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Galicia, J. F. Valdes; Valino, I.; Valore, L.; van den Berg, A. M.; van Elewyck, V.; Vazquez, R. A.; Veberic, D.; Veiga, A.; Velarde, A.; Venters, T.; Verzi, V.; Videla, M.; Villasenor, L.; Vorobiov, S.; Voyvodic, L.; Wahlberg, H.; Wainberg, O.; Warner, D.; Watson, A. A.; Westerhoff, S.; Wieczorek, G.; Wiencke, L.; Wilczynska, B.; Wilczynski, H.; Wileman, C.; Winnick, M. G.; Wu, H.; Wundheiler, B.; Yamamoto, T.; Younk, P.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zech, A.; Zepeda, A.; Ziolkowski, M.

    Data collected by the Pierre Auger Observatory provide evidence for anisotropy in the arrival directions of the cosmic rays with the highest-energies, which are correlated with the positions of relatively nearby active galactic nuclei (AGN) [Pierre Auger Collaboration, Science 318 (2007) 938]. The

  4. Selected Theoretical Studies Group contributions to the 14th International Cosmic Ray conference. [including studies on galactic molecular hydrogen, interstellar reddening, and on the origin of cosmic rays

    Science.gov (United States)

    1975-01-01

    The galactic distribution of H2 was studied through gamma radiation and through X-ray, optical, and infrared absorption measurements from SAS-2 and other sources. A comparison of the latitude distribution of gamma-ray intensity with reddening data shows reddening data to give the best estimate of interstellar gas in the solar vicinity. The distribution of galactic cosmic ray nucleons was determined and appears to be identical to the supernova remnant distribution. Interactions between ultrahigh energy cosmic-ray nuclei and intergalactic photon radiation fields were calculated, using the Monte Carlo method.

  5. An Alternative Explanation of the Varying Boron-to-carbon Ratio in Galactic Cosmic Rays

    Energy Technology Data Exchange (ETDEWEB)

    Eichler, David [Department of Physics, Ben-Gurion University, Be’er-Sheba 84105 (Israel)

    2017-06-10

    It is suggested that the decline with energy of the boron-to-carbon abundance ratio in Galactic cosmic rays is due, in part, to a correlation between the maximum energy attainable by shock acceleration in a given region of the Galactic disk and the grammage traversed before escape. In this case the energy dependence of the escape rate from the Galaxy may be less than previously thought and the spectrum of antiprotons becomes easier to understand.

  6. Modulation of galactic cosmic ray anisotropy in heliomagnetosphere: average sidereal daily variation

    International Nuclear Information System (INIS)

    Nagashima, K.; Morishita, I.; Yasue, S.

    1982-01-01

    The modulation of galactic anisotropy of cosmic rays caused by their deflection in the heliomagnetosphere is formulated. According to the formulation, the average sidereal i-th (2=1,2...) harmonic daily variation produced [from the anisotropy from an arbitrary direction can be expressed] by a linear combination of three basic vectors for unidirectional anisotropy and five basic vectors for bi-directional anisotropy. The general characteristics and main features of the sidereal daily variations in the modulation of the cosmic ray anistropy are presented. (U.K.)

  7. Sagittarius A* as an origin of the Galactic PeV cosmic rays?

    Energy Technology Data Exchange (ETDEWEB)

    Fujita, Yutaka [Department of Earth and Space Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Murase, Kohta; Kimura, Shigeo S., E-mail: fujita@vega.ess.sci.osaka-u.ac.jp, E-mail: murase@psu.edu, E-mail: szk323@psu.edu [Center for Particle and Gravitational Astrophysics, Department of Physics, Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States)

    2017-04-01

    Supernova remnants (SNRs) have commonly been considered as a source of the observed PeV cosmic rays (CRs) or a Galactic PeV particle accelerator ('Pevatron'). In this work, we study Sagittarius A* (Sgr A*), which is the low-luminosity active galactic nucleus of the Milky Way Galaxy, as another possible canditate of the Pevatron, because it sometimes became very active in the past. We assume that a large number of PeV CRs were injected by Sgr A* at the outburst about 10{sup 7} yr ago when the Fermi bubbles were created. We constrain the diffusion coefficient for the CRs in the Galactic halo on the condition that the CRs have arrived on the Earth by now, while a fairly large fraction of them have escaped from the halo. Based on a diffusion-halo model, we solve a diffusion equation for the CRs and compare the results with the CR spectrum on the Earth. The observed small anisotropy of the arrival directions of CRs may be explained if the diffusion coefficient in the Galactic disk is smaller than that in the halo. Our model predicts that a boron-to-carbon ratio should be energy-independent around the knee, where the CRs from Sgr A* become dominant. It is unlikely that the spectrum of the CRs accelerated at the outburst is represented by a power-law similar to the one for those responsible for the gamma-ray emission from the central molecular zone (CMZ) around the Galactic center.

  8. The Super-TIGER Instrument to Probe Galactic Cosmic Ray Origins

    Science.gov (United States)

    Mitchell, John W.; Binns, W. R.; Bose, R, G.; Braun, D. L.; Christian, E. R.; Daniels, W. M; DeNolfo, G. A.; Dowkontt, P. F.; Hahne, D. J.; Hams, T.; hide

    2011-01-01

    Super-TIGER (Super Trans-Iron Galactic Element Recorder) is under construction for the first of two planned Antarctic long-duration balloon flights in December 2012. This new instrument will measure the abundances of ultra-heavy elements (30Zn and heavier), with individual element resolution, to provide sensitive tests of the emerging model of cosmic-ray origins in OB associations and models of the mechanism for selection of nuclei for acceleration. Super-TIGER builds on the techniques of TIGER, which produced the first well-resolved measurements of elemental abundances of the elements 31Ga, 32Ge, and 34Se. Plastic scintillators together with acrylic and silica-aerogel Cherenkov detectors measure particle charge. Scintillating-fiber hodoscopes track particle trajectories. Super-TIGER has an active area of 5.4 sq m, divided into two independent modules. With reduced material thickness to decrease interactions, its effective geometry factor is approx.6.4 times larger than TIGER, allowing it to measure elements up to 42Mo with high statistical precision, and make exploratory measurements up to 56Ba. Super-TIGER will also accurately determine the energy spectra of the more abundant elements from l0Ne to 28Ni between 0.8 and 10 GeV/nucleon to test the hypothesis that microquasars or other sources could superpose spectral features. We will discuss the implications of Super-TIGER measurements for the study of cosmic-ray origins and will present the measurement technique, design, status, and expected performance, including numbers of events and resolution. Details of the hodoscopes, scintillators, and Cherenkov detectors will be given in other presentations at this conference.

  9. Prospects for identifying the sources of the Galactic cosmic rays with IceCube

    International Nuclear Information System (INIS)

    Halzen, Francis; Kappes, Alexander; O Murchadha, Aongus

    2008-01-01

    We quantitatively address whether IceCube, a kilometer-scale neutrino detector under construction at the South Pole, can observe neutrinos pointing back at the accelerators of the Galactic cosmic rays. The photon flux from candidate sources identified by the Milagro detector in a survey of the TeV sky is consistent with the flux expected from a typical cosmic-ray generating supernova remnant interacting with the interstellar medium. We show here that IceCube can provide incontrovertible evidence of cosmic-ray acceleration in these sources by detecting neutrinos. We find that the signal is optimally identified by specializing to events with energies above 30 TeV where the atmospheric neutrino background is low. We conclude that evidence for a correlation between the Milagro and IceCube sky maps should be conclusive after several years.

  10. A self-consistent model for the Galactic cosmic ray, antiproton and positron spectra

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    In this talk I will present the escape model of Galactic cosmic rays. This model explains the measured cosmic ray spectra of individual groups of nuclei from TeV to EeV energies. It predicts an early transition to extragalactic cosmic rays, in agreement with recent Auger data. The escape model also explains the soft neutrino spectrum 1/E^2.5 found by IceCube in concordance with Fermi gamma-ray data. I will show that within the same model one can explain the excess of positrons and antiprotons above 20 GeV found by PAMELA and AMS-02, the discrepancy in the slopes of the spectra of cosmic ray protons and heavier nuclei in the TeV-PeV energy range and the plateau in cosmic ray dipole anisotropy in the 2-50 TeV energy range by adding the effects of a 2 million year old nearby supernova.

  11. Galactic Cosmic-ray Transport in the Global Heliosphere: A Four-Dimensional Stochastic Model

    Science.gov (United States)

    Florinski, V.

    2009-04-01

    We study galactic cosmic-ray transport in the outer heliosphere and heliosheath using a newly developed transport model based on stochastic integration of the phase-space trajectories of Parker's equation. The model employs backward integration of the diffusion-convection transport equation using Ito calculus and is four-dimensional in space+momentum. We apply the model to the problem of galactic proton transport in the heliosphere during a negative solar minimum. Model results are compared with the Voyager measurements of galactic proton radial gradients and spectra in the heliosheath. We show that the heliosheath is not as efficient in diverting cosmic rays during solar minima as predicted by earlier two-dimensional models.

  12. MODULATION OF GALACTIC COSMIC RAY PROTONS AND ELECTRONS DURING AN UNUSUAL SOLAR MINIMUM

    International Nuclear Information System (INIS)

    Heber, B.; Kopp, A.; Gieseler, J.; Mueller-Mellin, R.; Fichtner, H.; Scherer, K.; Potgieter, M. S.; Ferreira, S. E. S.

    2009-01-01

    During the latest Ulysses out-of-ecliptic orbit the solar wind density, pressure, and magnetic field strength have been the lowest ever observed in the history of space exploration. Since cosmic ray particles respond to the heliospheric magnetic field in the expanding solar wind and its turbulence, the weak heliospheric magnetic field as well as the low plasma density and pressure are expected to cause the smallest modulation since the 1970s. In contrast to this expectation, the galactic cosmic ray (GCR) proton flux at 2.5 GV measured by Ulysses in 2008 does not exceed the one observed in the 1990s significantly, while the 2.5 GV GCR electron intensity exceeds the one measured during the 1990s by 30%-40%. At true solar minimum conditions, however, the intensities of both electrons and protons are expected to be the same. In contrast to the 1987 solar minimum, the tilt angle of the solar magnetic field has remained at about 30 deg. in 2008. In order to compare the Ulysses measurements during the 2000 solar magnetic epoch with those obtained 20 years ago, the former have been corrected for the spacecraft trajectory using latitudinal gradients of 0.25% deg. -1 and 0.19% deg. -1 for protons and electrons, respectively, and a radial gradient of 3% AU -1 . In 2008 and 1987, solar activity, as indicated by the sunspot number, was low. Thus, our observations confirm the prediction of modulation models that current sheet and gradient drifts prevent the GCR flux to rise to typical solar minimum values. In addition, measurements of electrons and protons allow us to predict that the 2.5 GV GCR proton intensity will increase by a factor of 1.3 if the tilt angle reaches values below 10 deg.

  13. Latitude survey investigation of galactic cosmic ray solar modulation during 1994-2007

    Energy Technology Data Exchange (ETDEWEB)

    Nuntiyakul, W.; Ruffolo, D.; Sáiz, A. [Department of Physics, Faculty of Science, Mahidol University, Bangkok 10400 (Thailand); Evenson, P.; Bieber, J. W.; Clem, J.; Pyle, R. [Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); Duldig, M. L.; Humble, J. E., E-mail: w.nuntiyakul@gmail.com, E-mail: david.ruf@mahidol.ac.th, E-mail: alejandro.sai@mahidol.ac.th, E-mail: evenson@udel.edu, E-mail: jwbieber@bartol.udel.edu, E-mail: clem@bartol.udel.edu, E-mail: pyle@bartol.udel.edu, E-mail: John.Humble@utas.edu.au, E-mail: Marc.Duldig@utas.edu.au [School of Physical Sciences, University of Tasmania, Hobart, Tasmania 7001 (Australia)

    2014-11-01

    The Galactic cosmic ray spectrum exhibits subtle variations over the 22 yr solar magnetic cycle in addition to the more dramatic variations over the 11 yr sunspot cycle. Neutron monitors are large ground-based detectors that provide accurate measurements of variations in the cosmic ray flux at the top of the atmosphere above the detector. At any given location the magnetic field of the Earth excludes particles below a well-defined rigidity (momentum per unit charge) known as the cutoff rigidity, which can be accurately calculated using detailed models of the geomagnetic field. By carrying a neutron monitor to different locations, e.g., on a ship, the Earth itself serves as a magnet spectrometer. By repeating such latitude surveys with identical equipment, a sensitive measurement of changes in the spectrum can be made. In this work, we analyze data from the 1994 through 2007 series of latitude surveys conducted by the Bartol Research Institute, the University of Tasmania, and the Australian Antarctic Division. We confirm the curious 'crossover' in spectra measured near solar minima during epochs of opposite solar magnetic polarity, and show that it is directly related to a sudden change in the spectral behavior of solar modulation at the time of the polarity reversal, as revealed from contemporaneous variations in the survey data and a fixed station. We suggest that the spectral change and crossover result from the interaction of effects due to gradient/curvature drifts with a systematic change in the interplanetary diffusion coefficient caused by turbulent magnetic helicity.

  14. The modulation of galactic cosmic rays as described by a three-dimensional drift model

    International Nuclear Information System (INIS)

    Potgieter, M.S.

    1984-01-01

    An outline of the present state of knowledge about the effect of drift on the modulation of galactic cosmic rays is given. Various observations related to the reversal of the solar magnetic field polarity are discussed. Comprehensive numerical solutions of the steady-state cosmic-ray transport equation in an axially-symmetric three-dimensional heliosphere, including drift are presented. This is an extention of the continuing effort of the past six years to understand the effect and importance of drift on the transport of galactic cosmic rays in the heliosphere. A flat neutral sheet which coincides with the equatorial plane is assumed. A general method of calculating the drift velocity in the neutral sheet including that used previously by other authors is presented. The effect of changing various modulation parameters on the drift solutions are illustrated in detail. The real significance of drift is illustrated by using Gaussian input spectra on the modulation boundary. A carefully selected set of modulation parameters is used to illustrate to what extent a drift model can explain prominent observational features. It is concluded that drift is important in in the process of cosmic-ray transport and must as such be considered in all modulation studies, but that it is not overwhelmingly dominant as previously anticipated

  15. ANOMALOUS TRANSPORT OF HIGH-ENERGY COSMIC RAYS IN GALACTIC SUPERBUBBLES. I. NUMERICAL SIMULATIONS

    International Nuclear Information System (INIS)

    Barghouty, A. F.; Schnee, D. A.

    2012-01-01

    We present a simple continuous-time random-walk model for the transport of energetic particles accelerated by a collection of supernova explosions in a galactic superbubble, developed to simulate and highlight signatures of anomalous transport on the particles' evolution and their spectra in a multi-shock context. We assume standard diffusive shock acceleration (DSA) theory for each shock encounter. The superbubble (an OB stars association) is idealized as a heterogeneous region of particle sources and sinks bounded by a random surface. The model is based on two coupled stochastic differential equations and is applied for protons and alpha particles. Using characteristic values for a typical bubble, our simulations suggest that acceleration and transport in the bubble may be sub-diffusive. In addition, a spectral break in the particles' evolution and spectra is evident located at ≈10 15 eV for protons and ≈3 × 10 15 eV for alphas. Our simulations are consistent with a bubble's mean magnetic field strength of ≈1 μG and a shock separation distance ∼0.1 × the characteristic radius of the bubble. The simulations imply that the diffusion coefficient (for the elementary shock acceleration process) is ∼ 27 cm 2 s –1 at 1 GeV/c. While the sub-diffusive transport is readily attributed to the stochastic nature of the acceleration time according to DSA theory, the spectral break appears to be an artifact of transport in a finite medium. These simulations point to a new and intriguing phenomenon associated with the statistical nature of collective acceleration of high-energy cosmic rays in galactic superbubbles.

  16. Ultrahigh energy cosmic ray nuclei from extragalactic pulsars and the effect of their Galactic counterparts

    International Nuclear Information System (INIS)

    Fang, Ke; Olinto, Angela V.; Kotera, Kumiko

    2013-01-01

    The acceleration of ultrahigh energy nuclei in fast spinning newborn pulsars can explain the observed spectrum of ultrahigh energy cosmic rays and the trend towards heavier nuclei for energies above 10 19 eV as reported by the Auger Observatory. Pulsar acceleration implies a hard injection spectrum ( ∼ E −1 ) due to pulsar spin down and a maximum energy E max ∼ Z 10 19 eV due to the limit on the spin rate of neutron stars. We have previously shown that the escape through the young supernova remnant softens the spectrum, decreases slightly the maximum energy, and generates secondary nuclei. Here we show that the distribution of pulsar birth periods and the effect of propagation in the interstellar and intergalactic media modifies the combined spectrum of all pulsars. By assuming a normal distribution of pulsar birth periods centered at 300 ms, we show that the contribution of extragalactic pulsar births to the ultrahigh energy cosmic ray spectrum naturally gives rise to a contribution to very high energy cosmic rays (VHECRs, between 10 16 and 10 18 eV) by Galactic pulsar births. The required injected composition to fit the observed spectrum depends on the absolute energy scale, which is uncertain, differing between Auger Observatory and Telescope Array. The contribution of Galactic pulsar births can also bridge the gap between predictions for cosmic ray acceleration in supernova remnants and the observed spectrum just below the ankle, depending on the composition of the cosmic rays that escape the supernova remnant and the diffusion behavior of VHECRs in the Galaxy

  17. 2-D Modelling of Long Period Variations of Galactic Cosmic Ray Intensity

    International Nuclear Information System (INIS)

    Siluszyk, M; Iskra, K; Alania, M

    2015-01-01

    A new two-dimensional (2-D) time dependent model describing long-period variations of the Galactic Cosmic Ray (GCR) intensity has been developed. New approximations for the changes of the magnitude B of the Interplanetary Magnetic Field (IMF), the tilt angle δ of the Heliospheric Neutral Sheet (HNS) and drift effects of the GCR particles have been included into the model. Moreover, temporal changes of the exponent γ expressing the power law - rigidity dependence of the amplitudes of the 11-year variation of the GCR intensity have been added. We show that changes of the expected GCR particle density precedes changes of the GCR intensity measured by the Moscow Neutron (MN) monitor by about 18 months. So ∼18 months can be taken as an effective delay time between the expected intensity caused by the combined influence of the changes of the parameters implemented in the time-dependent 2-D model and the GCR intensity measured by neutron monitors during the 21 cycle of solar activity. (paper)

  18. CHARGE SPECTRUM OF HEAVY AND SUPERHEAVY COMPONENTS OF GALACTIC COSMIC RAYS: RESULTS OF THE OLIMPIYA EXPERIMENT

    Energy Technology Data Exchange (ETDEWEB)

    Alexeev, Victor; Kalinina, Galina; Pavlova, Tatyana, E-mail: aval37@mail.ru, E-mail: gakalin@mail.ru, E-mail: pavlova4tat@mail.ru [Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, 19 Kosygin Str., Moscow 119991 (Russian Federation); and others

    2016-10-01

    The aim of the OLIMPIYA experiment is to search for and identify traces of heavy and superheavy nuclei of galactic cosmic rays (GCR) in olivine crystals from stony–iron meteorites serving as nuclear track detectors. The method is based on layer-by-layer grinding and etching of particle tracks in these crystals. Unlike the techniques of other authors, this annealing-free method uses two parameters: the etching rate along the track ( V {sub etch}) and the total track length ( L ), to identify charge Z of a projectile. A series of irradiations with different swift heavy ions at the accelerator facilities of GSI (Darmstadt) and IMP (Lanzhou) were performed in order to determine and calibrate the dependence of projectile charge on V {sub etch} and L . To date, one of the most essential results of the experiment is the obtained charge spectrum of GCR nuclei within the range of Z > 40, based on about 11.6 thousand processed tracks. As the result of data processing, 384 nuclei with charges Z ≥ 75 have been identified, including 10 nuclei identified as actinides (90 < Z < 103). Three tracks were identified to be produced by nuclei with charges 113 < Z < 129. Such nuclei may be part of the Island of Stability of transfermium elements.

  19. The superTIGER instrument: Measurement of elemental abundances of ultra-heavy galactic cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Binns, W. R.; Bose, R. G.; Braun, D. L.; Dowkontt, P. F.; Israel, M. H.; Moore, P.; Murphy, R. P.; Olevitch, M. A.; Rauch, B. F. [Washington University, St. Louis, MO 63130 (United States); Brandt, T. J.; Daniels, W. M.; Fitzsimmons, S. P.; Hahne, D. J.; Hams, T.; Link, J. T.; Mitchell, J. W.; Sakai, K. [NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Klemic, J.; Labrador, A. W.; Mewaldt, R. A., E-mail: wrb@wustl.edu [California Institute of Technology, Pasadena, CA 91125 (United States); and others

    2014-06-10

    The SuperTIGER (Super Trans-Iron Galactic Element Recorder) instrument was developed to measure the abundances of galactic cosmic-ray elements from {sub 10}Ne to {sub 40}Zr with individual element resolution and the high statistics needed to test models of cosmic-ray origins. SuperTIGER also makes exploratory measurements of the abundances of elements with 40 < Z ≤ 60 and measures the energy spectra of the more abundant elements for Z ≤ 30 from about 0.8 to 10 GeV/nucleon. This instrument is an enlarged and higher resolution version of the earlier TIGER instrument. It was designed to provide the largest geometric acceptance possible and to reach as high an altitude as possible, flying on a standard long-duration 1.11 million m{sup 3} balloon. SuperTIGER was launched from Williams Field, McMurdo Station, Antarctica, on 2012 December 8, and made about 2.7 revolutions around the South Pole in 55 days of flight, returning data on over 50 × 10{sup 6} cosmic-ray nuclei with Z ≥ 10, including ∼1300 with Z > 29 and ∼60 with Z > 49. Here, we describe the instrument, the methods of charge identification employed, the SuperTIGER balloon flight, and the instrument performance.

  20. CAN ULTRAHIGH-ENERGY COSMIC RAYS COME FROM GAMMA-RAY BURSTS? COSMIC RAYS BELOW THE ANKLE AND GALACTIC GAMMA-RAY BURSTS

    International Nuclear Information System (INIS)

    Eichler, David; Pohl, Martin

    2011-01-01

    The maximum cosmic-ray energy achievable by acceleration by a relativistic blast wave is derived. It is shown that forward shocks from long gamma-ray bursts (GRBs) in the interstellar medium accelerate protons to large enough energies, and have a sufficient energy budget, to produce the Galactic cosmic-ray component just below the ankle at 4 x 10 18 eV, as per an earlier suggestion. It is further argued that, were extragalactic long GRBs responsible for the component above the ankle as well, the occasional Galactic GRB within the solar circle would contribute more than the observational limits on the outward flux from the solar circle, unless an avoidance scenario, such as intermittency and/or beaming, allows the present-day local flux to be less than 10 -3 of the average. Difficulties with these avoidance scenarios are noted.

  1. Energy spectra and charge composition of galactic cosmic rays measured in ATIC-2 experiment

    International Nuclear Information System (INIS)

    Zatsepin, V.I.; Bat'kov, K.E.; Bashindzhagyan, G.L.

    2004-01-01

    The ATIC (Advanced Thin Ionization Calorimeter) balloon experiment is intended for measuring the energy spectra of the galactic cosmic rays with the individual resolution by the charge from protons to iron within the energy range from 50 GeV up to 100 TeV. The silicon detector matrix, making it possible to solve on the inverse current by means of the detector charge high segmentation, was applied for the first time in the high-energy cosmic rays for the charge measurement. The ATIC completed two successful flights in the Antarctica since 28.12.2000 up to 13.01.2001 (the ATIC-1 test flight) and since 29.12.2002 up to 18.01.2003 (the ATIC-2 scientific flight). The current state of the analysis of the spectra, measured in the ATIC-2 scientific flight, are presented in this work and the obtained results are compared with the model forecasts results [ru

  2. At what particle energy do extragalactic cosmic rays start to predominate?

    International Nuclear Information System (INIS)

    Wibig, Tadeusz; Wolfendale, Arnold W

    2005-01-01

    We have previously argued (e.g. Szabelski et al 2002 Astropart. Phys. 17 125) that the well-known 'ankle' in the cosmic ray energy spectrum, at log E (eV) ∼ 18.7-19.0, marks the transition from mainly galactic sources at lower energies to mainly extragalactic above. Recently, however, there have been claims for lower transitional energies, specifically from log E (eV) ∼ 17.0 (Thompson et al 2004 Proc. Catania Cosmic Ray Conf.) via 17.2-17.8 (Berezinsky et al 2004 Astropart. Phys. 21 617) to 18.0 (Hillas 2004 Proc. Leeds Cosmic Ray Conf.). In our model the ankle arises naturally from the sum of simple power law-spectra with slopes differing by Δγ ∼ 1.8; from differential slope γ = -3.8 for galactic particles (near log E = 19) to γ ∼ -2.0 for extragalactic sources. In the other models, on the other hand, the ankle is intrinsic to the extragalactic component alone, and arises from the shape of the rate of energy loss versus energy for the (assumed) protons interacting with the cosmic microwave background (CMB). Our detailed analysis of the world's data on the ultra-high energy spectrum shows that taken together, or separately, the resulting mean sharpness of the ankle (second derivative of the log(intensity x E 3 ) with respect to log E) is consistent with our 'mixed' model. For explanation in terms of extragalactic particles alone, however, the ankle will be at the wrong energy-for reasonable production models and of insufficient magnitude if, as seems likely, there is still a significant fraction of heavy nuclei at the ankle energy

  3. GALACTIC COSMIC RAYS IN THE LOCAL INTERSTELLAR MEDIUM: VOYAGER 1 OBSERVATIONS AND MODEL RESULTS

    Energy Technology Data Exchange (ETDEWEB)

    Cummings, A. C.; Stone, E. C. [California Institute of Technology, Pasadena, CA 91125 (United States); Heikkila, B. C.; Lal, N. [Goddard Space Flight Center. Greenbelt, MD 20771 (United States); Webber, W. R. [New Mexico State University, Las Cruces, NM 88003 (United States); Jóhannesson, G. [University of Iceland, Reykjavik (Iceland); Moskalenko, I. V.; Orlando, E.; Porter, T. A. [HEPL and KIPAC, Stanford University, Stanford, CA 94305 (United States)

    2016-11-01

    Since 2012 August Voyager 1 has been observing the local interstellar energy spectra of Galactic cosmic-ray nuclei down to 3 MeV nuc{sup -1} and electrons down to 2.7 MeV. The H and He spectra have the same energy dependence between 3 and 346 MeV nuc{sup -1}, with a broad maximum in the 10–50 MeV nuc{sup -1} range and a H/He ratio of 12.2 ± 0.9. The peak H intensity is ∼15 times that observed at 1 AU, and the observed local interstellar gradient of 3–346 MeV H is -0.009 ± 0.055% AU{sup -1}, consistent with models having no local interstellar gradient. The energy spectrum of electrons ( e {sup -} + e {sup +}) with 2.7–74 MeV is consistent with E {sup -1.30±0.05} and exceeds the H intensity at energies below ∼50 MeV. Propagation model fits to the observed spectra indicate that the energy density of cosmic-ray nuclei with >3 MeV nuc{sup -1} and electrons with >3 MeV is 0.83–1.02 eV cm{sup -3} and the ionization rate of atomic H is in the range of 1.51–1.64 × 10{sup -17} s{sup -1}. This rate is a factor >10 lower than the ionization rate in diffuse interstellar clouds, suggesting significant spatial inhomogeneity in low-energy cosmic rays or the presence of a suprathermal tail on the energy spectrum at much lower energies. The propagation model fits also provide improved estimates of the elemental abundances in the source of Galactic cosmic rays.

  4. Observation of galactic cosmic ray spallation events from the SoHO mission 20-Year operation of LASCO

    Science.gov (United States)

    Koutchmy, S.; Tavabi, E.; Urtado, O.

    2018-05-01

    A shower of secondary Cosmic Ray (CR) particles is produced at high altitudes in the Earth's atmosphere, so the primordial Galactic Cosmic Rays (GCRs) are never directly measured outside the Earth magnetosphere and atmosphere. They approach the Earth and other planets in the complex pattern of rigidity's dependence, generally excluded by the magnetosphere. GCRs revealed by images of single nuclear reactions also called spallation events are described here. Such an event was seen on Nov. 29, 2015 using a unique LASCO C3 space coronagraph routine image taken during the Solar and Heliospheric Observatory (SoHO) mission observing uninterruptedly at the Lagrangian L1 point. The spallation signature of a GCR identified well outside the Earth's magnetosphere is obtained for the 1st time. The resulting image includes different diverging linear "tracks" of varying intensity, leading to a single pixel; this frame identifies the site on the silicon CCD chip of the coronagraph camera. There was no solar flare reported at that time, nor Coronal Mass Ejection (CME) and no evidence of optical debris around the spacecraft. More examples of smaller CR events have been discovered through the 20 years of continuous observations from SoHO. This is the first spallation event from a CR, recorded outside the Earth's magnetosphere. We evaluate the probable energy of these events suggesting a plausible galactic source.

  5. Solar flare and galactic cosmic ray tracks in lunar samples and meteorites - What they tell us about the ancient sun

    International Nuclear Information System (INIS)

    Crozaz, G.

    1980-01-01

    Evidence regarding the past activity of the sun in the form of nuclear particle tracks in lunar samples and meteorites produced by heavy ions in galactic cosmic rays and solar flares is reviewed. Observations of track-rich grains found in deep lunar cores and meteorite interiors are discussed which demonstrate the presence of solar flare activity for at least the past 4 billion years, and the similarity of track density profiles from various lunar and meteoritic samples with those in a glass filter from Surveyor 3 exposed at the lunar surface for almost three years is presented as evidence of the relative constancy of the solar flare energy spectrum over the same period. Indications of a heavy ion enrichment in solar flares are considered which are confirmed by recent satellite measurements, although difficult to quantify in lunar soil grains. Finally, it is argued that, despite previous claims, there exists as yet no conclusive evidence for either a higher solar activity during the early history of the moon or a change in galactic cosmic ray intensity, average composition or spectrum over the last 50 million years

  6. Modulation of galactic and anomalous cosmic rays in the inner heliosphere

    Science.gov (United States)

    Heber, B.

    Our knowledge on how galactic and anomalous cosmic rays are modulated in the inner heliosphere has been dramatically enlarged due to measurements provided by several missions launched in the past ten years. The current paradigma of singly charged anomalous cosmic rays has been confirmed by recent measurements from the SAMPEX and ACE satelite. Ulysses explored the inner heliosphere at polar regions during the last solar minimum period and is heading again to high heliographic latitudes during the time of the conference in July, 2000. The Sun approaches maximum activity when the spacecraft is at high heliographic latitudes giving us for the first time the possibility to explore modulation of cosmic rays in the inner three-dimensional heliosphere during such conditions. Ulysses electron measurements in addition to the 1 AU ICE electron and IMP helium measurements allows us to investigate charge sign dependent modulation over a full 22-year solar magnetic cycle. Implications of these observations for our understanding of different modulation processes in the inner three-dimensional heliosphere are presented.

  7. Diffuse galactic continuum emission measured by COMPTEL and the cosmic-ray electron spectrum

    Science.gov (United States)

    Strong, A. W.; Diehl, R.; Schoenfelder, V.; Varendorff, M.; Youssefi, G.; Bloemen, H.; Hermsen, W.; De Vries, C.; Morris, D.; Stacy, J. G.

    1994-01-01

    Diffuse galactic continuum gamma-ray emission in the 0.75-30 MeV range from the inner Galaxy has been studied using data from COMPTEL on the Compton Gamma-Ray Observatory. Observations of the inner Galaxy from the Sky Survey have been used. The imaging properties of COMPTEL enable spatial analysis of the gamma-ray distribution using model fitting. A model based on atomic and molecular gas distributions in the Galaxy has been used to derive the emissivity spectrum of the gamma-ray emission and this spectrum is compared with theoretical estimates of bremsstrahlung emission from cosmic-ray electrons.

  8. Measurement of the isotopic composition of galactic cosmic ray carbon, nitrogen and oxygen

    International Nuclear Information System (INIS)

    Wiedenbeck, M.E.; Greiner, D.E.; Bieser, F.S.; Crawford, H.J.; Heckman, H.H.; Lindstrom, P.J.

    1979-06-01

    The results of an investigation of the isotopic composition of galactic cosmic ray carbon, nitrogen and oxygen (E approx. 80 to 230 MeV/amu) made using the U.C. Berkeley HKH instrument aboard the ISEE-3 spacecraft are reported. The combination of high mass resolution and a large statistical sample makes possible a precise determination of the relative isotopic abundances for these elements. In local interplanetary space we find: 13 C/C = 0.067 +- 0.008, 15 N/N = 0.54 +- 0.03, 17 O/O 18 O/O = 0.019 +- 0.003

  9. The galactic magnetic field and propagation of ultrahigh energy cosmic rays

    Czech Academy of Sciences Publication Activity Database

    Prouza, Michael; Šmída, Radomír

    2003-01-01

    Roč. 410, - (2003), s. 1-10 ISSN 0004-6361 R&D Projects: GA AV ČR IAA1010928; GA MŠk LN00A006; GA MŠk LA 134 Institutional research plan: CEZ:AV0Z1010920 Keywords : cosmic rays * magnetic fields * Galaxy Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 3.843, year: 2003

  10. Galactic cosmic-ray intensity to a heliocentric distance of 18 AU

    International Nuclear Information System (INIS)

    Van Allen, J.A.

    1980-01-01

    An updated report is given of observations of galactic cosmic-ray intensity to heliocentric radial distance of 8.6 and 18.4 AU with Pioneer 11 and Pioneer 10, respectively. Solar activity via the magnetic structure of the interplanetary medium continues to modulate the intensity out to the greatest distance reached thus far. During the 7 year period 1972 March to 1979 March, the galactic cosmic-ray intensity E/sub p/>80 MeV as measured by detectors on Pioneers 10 and 11 exhibited aperiodic temporal variations by about a factor of 2 and on a time scale of the order of a year and quasi-persistent cyclic variations of 26 day period and amplitude a few percent. The former are attributed to overall changes in the magnetic field structure of the heliosphere, the latter to fast-slow solar wind streams in and near the ecliptic plane and not to toward-away magnetic field sectors. The apparent heliographic latitude dependence of intensity is 0( +- 1.5)% per 10 0 in the latitude range +7 0 .7 to +15. 0 8, though it is possible that radially dependent temporal variations over the large difference in the heliocentric radial distances of the two spacecraft may make this result of limited significance. For protons of energy E/sub p/>80 MeV, there is a fairly consistent heliocentric radial gradient of +2.1( +- 0.3)% per AU integral intensity until 1978 April--May, at which time a substantial disruption of the distribution of cosmic rays in the heliosphere occurred

  11. The galactic center GeV excess from a series of leptonic cosmic-ray outbursts

    Energy Technology Data Exchange (ETDEWEB)

    Cholis, Ilias [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Evoli, Carmelo [Univ. Hamburg, Hamburg (Germany); Calore, Francesca [Univ. of Amsterdam, Amsterdam (Netherlands); Linden, Tim [Univ. of Chicago, Chicago, IL (United States); Weniger, Christoph [Univ. of Amsterdam, Amsterdam (Netherlands); Hooper, Dan [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Univ. of Chicago, Chicago, IL (United States)

    2015-06-16

    It has been proposed that a recent outburst of cosmic-ray electrons could account for the excess of GeV-scale gamma rays observed from the region surrounding the Galactic Center. After studying this possibility in some detail, we identify scenarios in which a series of leptonic cosmic-ray outbursts could plausibly generate the observed excess. The morphology of the emission observed outside of ~1° – 2° from the Galactic Center can be accommodated with two outbursts, one which took place approximately ~106 years ago, and another (injecting only about 10% as much energy as the first) about ~105 years ago. The emission observed from the innermost ~1° – 2° requires one or more additional recent outbursts and/or a contribution from a centrally concentrated population of unresolved millisecond pulsars. Furthermore, in order to produce a spectrum that is compatible with the measured excess (whose shape is approximately uniform over the region of the excess), the electrons from the older outburst must be injected with significantly greater average energy than those injected more recently, enabling their spectra to be similar after ~106 years of energy losses.

  12. LISA Pathfinder test-mass charging during galactic cosmic-ray flux short-term variations

    Science.gov (United States)

    Grimani, C.; Fabi, M.; Lobo, A.; Mateos, I.; Telloni, D.

    2015-02-01

    Metal free-floating test masses aboard the future interferometers devoted to gravitational wave detection in space are charged by galactic and solar cosmic rays with energies \\gt 100 MeV/n. This process represents one of the main sources of noise in the lowest frequency band (\\lt 10-3 Hz) of these experiments. We study here the charging of the LISA Pathfinder (LISA-PF) gold-platinum test masses due to galactic cosmic-ray (GCR) protons and helium nuclei with the Fluka Monte Carlo toolkit. Projections of the energy spectra of GCRs during the LISA-PF operations in 2015 are considered. This work was carried out on the basis of the solar activity level and solar polarity epoch expected for LISA-PF. The effects of GCR short-term variations are evaluated here for the first time. Classical Forbush decreases, GCR variations induced by the Sun rotation, and fluctuations in the LISA-PF frequency bandwidth are discussed.

  13. Constraining sources of ultrahigh energy cosmic rays and shear acceleration mechanism of particles in relativistic jets

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ruoyu

    2015-06-10

    Ultrahigh energy cosmic rays are extreme energetic particles from outer space. They have aroused great interest among scientists for more than fifty years. However, due to the rarity of the events and complexity of the process of their propagation to Earth, they are still one of the biggest puzzles in modern high energy astrophysics. This dissertation is dedicated to study the origin of ultrahigh energy cosmic rays from various aspects. Firstly, we discuss a possible link between recently discovered sub-PeV/PeV neutrinos and ultrahigh energy cosmic rays. If these two kinds of particles share the same origin, the observation of neutrinos may provide additional and non-trivial constraints on the sources of ultrahigh energy cosmic rays. Secondly, we jointly employ the chemical composition measurement and the arrival directions of ultrahigh energy cosmic rays, and find a robust upper limit for distances of sources of ultrahigh energy cosmic rays above ∝55 EeV, as well as a lower limit for their metallicities. Finally, we study the shear acceleration mechanism in relativistic jets, which is a more efficient mechanism for the acceleration of higher energy particle. We compute the acceleration efficiency and the time-dependent particle energy spectrum, and explore the feature of synchrotron radiation of the accelerated particles. The possible realizations of this mechanism for acceleration of ultrahigh energy cosmic rays in different astrophysical environments is also discussed.

  14. Particle injection and cosmic ray acceleration at collisionless parallel shocks

    International Nuclear Information System (INIS)

    Quest, K.B.

    1987-01-01

    The structure of collisionless parallel shocks is studied using one-dimensional hybrid simulations, with emphasis on particle injection into the first-order Fermi acceleration process. It is argued that for sufficiently high Mach number shocks, and in the absence of wave turbulence, the fluid firehose marginal stability condition will be exceeded at the interface between the upstream, unshocked, plasma and the heated plasma downstream. As a consequence, nonlinear, low-frequency, electromagnetic waves are generated and act to slow the plasma and provide dissipation for the shock. It is shown that large amplitude waves at the shock ramp scatter a small fraction of the upstream ions back into the upstream medium. These ions, in turn, resonantly generate the electromagnetic waves that are swept back into the shock. As these waves propagate through the shock they are compressed and amplified, allowing them to non-resonantly scatter the bulk of the plasma. Moreover, the compressed waves back-scatter a small fraction of the upstream ions, maintaining the shock structure in a quasi-steady state. The back-scattered ions are accelerated during the wave generation process to 2 to 4 times the ram energy and provide a likely seed population for cosmic rays. 49 refs., 7 figs

  15. Cloud a particle beam facility to investigate the influence of cosmic rays on clouds

    CERN Document Server

    Kirkby, Jasper

    2001-01-01

    Palaeoclimatic data provide extensive evidence for solar forcing of the climate during the Holocene and the last ice age, but the underlying mechanism remains a mystery. However recent observations suggest that cosmic rays may play a key role. Satellite data have revealed a surprising correlation between cosmic ray intensity and the fraction of the Earth covered by low clouds \\cite{svensmark97,marsh}. Since the cosmic ray intensity is modulated by the solar wind, this may be an important clue to the long-sought mechanism for solar-climate variability. In order to test whether cosmic rays and clouds are causally linked and, if so, to understand the microphysical mechanisms, a novel experiment known as CLOUD\\footnotemark\\ has been proposed \\cite{cloud_proposal}--\\cite{cloud_addendum_2}. CLOUD proposes to investigate ion-aerosol-cloud microphysics under controlled laboratory conditions using a beam from a particle accelerator, which provides a precisely adjustable and measurable artificial source of cosmic rays....

  16. Evolution of the Deep-space Galactic Cosmic Ray Lineal Energy Transfer Spectrum through Tissue Equivalent Plastic

    Science.gov (United States)

    Case, A. W.; Kasper, J. C.; Spence, H. E.; Golightly, M. J.; Schwadron, N. A.; Mazur, J. E.; Blake, J. B.; Looper, M. D.; Townsend, L.; Zeitlin, C. J.

    2011-12-01

    The Cosmic Ray Telescope for the Effects of Radiation is an energetic particle telescope that resides on the Lunar Reconnaissance Orbiter spacecraft, currently in a 50 km circular lunar polar orbit. The telescope consists of 6 silicon semi-conductor detectors placed in pairs that surround two pieces of Tissue Equivalent Plastic (TEP), which serve to absorb energy from particles as they transit through the instrument. Particles with energies greater than 12 MeV/nucleon can penetrate the outermost shield and be measured by the instrument. The primary measurement made by the instrument is of the Linear Energy Transfer (LET) of energetic particles as they transit through the telescope. CRaTER measures the LET spectrum with unprecedented energy resolution and has done so during a period of historically low solar activity that led to record high intensities of Galactic Cosmic Rays (GCR). These LET spectra are used to study changes in the properties of the incoming particles, and to make detailed measurements of the radiation doses human explorers will experience in deep space on missions to the moon, to asteroids, or to Mars. We present LET spectra accumulated during 2009 and 2010. We show how the LET spectrum evolves through the instrument as the GCR interact with the TEP. Due to the importance of these measurements for human effects, our extensive absolute calibration procedures are presented. Of particular note is a significant reduction in the flux of particles with LET greater than 10 keV/um for detectors that lie deeper within the telescope stack, due to the attenuation of high LET particles within the TEP. By measuring this attenuation we can estimate the depth in human tissue where the highest LET particles that are most likely to cause genetic damage pose the greatest threat to humans in space.

  17. Cosmic-Ray Transport in Heliospheric Magnetic Structures. II. Modeling Particle Transport through Corotating Interaction Regions

    Energy Technology Data Exchange (ETDEWEB)

    Kopp, Andreas [Université Libre de Bruxelles, Service de Physique Statistique et des Plasmas, CP 231, B-1050 Brussels (Belgium); Wiengarten, Tobias; Fichtner, Horst [Institut für Theoretische Physik IV, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Effenberger, Frederic [Department of Physics and KIPAC, Stanford University, Stanford, CA 94305 (United States); Kühl, Patrick; Heber, Bernd [Institut für Experimentelle und Angewandte Physik, Christian-Albrecht-Universität zu Kiel, D-24098 Kiel (Germany); Raath, Jan-Louis; Potgieter, Marius S. [Centre for Space Research, North-West University, 2520 Potchefstroom (South Africa)

    2017-03-01

    The transport of cosmic rays (CRs) in the heliosphere is determined by the properties of the solar wind plasma. The heliospheric plasma environment has been probed by spacecraft for decades and provides a unique opportunity for testing transport theories. Of particular interest for the three-dimensional (3D) heliospheric CR transport are structures such as corotating interaction regions (CIRs), which, due to the enhancement of the magnetic field strength and magnetic fluctuations within and due to the associated shocks as well as stream interfaces, do influence the CR diffusion and drift. In a three-fold series of papers, we investigate these effects by modeling inner-heliospheric solar wind conditions with the numerical magnetohydrodynamic (MHD) framework Cronos (Wiengarten et al., referred as Paper I), and the results serve as input to a transport code employing a stochastic differential equation approach (this paper). While, in Paper I, we presented results from 3D simulations with Cronos, the MHD output is now taken as an input to the CR transport modeling. We discuss the diffusion and drift behavior of Galactic cosmic rays using the example of different theories, and study the effects of CIRs on these transport processes. In particular, we point out the wide range of possible particle fluxes at a given point in space resulting from these different theories. The restriction of this variety by fitting the numerical results to spacecraft data will be the subject of the third paper of this series.

  18. The connection of the interplanetary magnetic field turbulence and rigidity spectrum of Forbush decrease of the galactic cosmic ray intensity

    International Nuclear Information System (INIS)

    Wawrzynczak, A; Alania, M V

    2015-01-01

    We analyze the temporal changes in the rigidity spectrum of Forbush decrease (Fd) of the galactic cosmic ray (GCR) intensity observed in November 2004. We compute the rigidity spectrum in two energy ranges based on the daily data from the worldwide network of neutron monitors and Nagoya ground muon telescope. We demonstrate that the changes in the rigidity spectrum of Fd are linked to the evolution/decay of the interplanetary magnetic field (IMF) turbulence during various phases of the Fd. We analyze the time-evolution of the state of the turbulence of the IMF in various frequency ranges during the Fd. Performed analysis show that the decrease of the exponent ν of the Power Spectral Density (PSD ∝ f −ν , where f is frequency) of the IMF turbulence with decreasing frequency lead to the soft rigidity spectrum of Fd for GCR particles with relatively higher energies. (paper)

  19. Protracted storage of CR chondrules in a region of the disk transparent to galactic cosmic rays

    Science.gov (United States)

    Roth, Antoine S. G.; Metzler, Knut; Baumgartner, Lukas P.; Hofmann, Beda A.; Leya, Ingo

    2017-10-01

    Renazzo-type carbonaceous (CR) chondrites are accretionary breccias that formed last. As such they are ideal samples to study precompaction exposures to cosmic rays. Here, we present noble gas data for 24 chondrules and 3 dark inclusion samples (DIs) from Shişr 033 (CR2). The meteorite was selected based on the absence of implanted solar wind noble gases and an anomalous oxygen isotopic composition of the DIs; the oxygen isotopes match those in CV3 and CO3 chondrites. Our samples contain variable mixtures of galactic cosmic ray (GCR)-produced cosmogenic noble gases and trapped noble gases of presolar origin. Remarkably, all chondrules have cosmogenic 3He and 21Ne concentrations up to 4.3 and 7.1 times higher than the DIs, respectively. We derived an average 3He-21Ne cosmic ray exposure (CRE) age for Shişr 033 of 2.03 ± 0.20 Ma (2 SD) and excesses in cosmogenic 3He and 21Ne in chondrules (relative to the DIs) in the range (in 10-8 cm3STP/g) 3.99-7.76 and 0.94-1.71, respectively. Assuming present-day GCR flux density, the excesses translate into average precompaction 3He-21Ne CRE ages of 3.1-27.3 Ma depending on the exposure geometry. The data can be interpreted assuming a protracted storage of a single chondrule generation prior to the final assembly of the Shişr 033 parent body in a region of the disk transparent to GCRs.

  20. Response of spherical gravitational wave antenna modes to high-energy cosmic ray particles

    International Nuclear Information System (INIS)

    Jr, R M Marinho; Magalhaes, N S; Aguiar, O D; Frajuca, C

    2002-01-01

    High-energy cosmic ray particles are expected to be a significant source of noise in resonant mass gravitational wave detectors close to the quantum limit. The spherical, fourth generation antennas have been designed to attain such a limit. In this work we will show how the energy of a cosmic ray particle interacting with such an antenna is distributed over its eigenmodes. We will then make some comments on the relevant consequences of such a distribution for gravitational wave detection

  1. Response of spherical gravitational wave antenna modes to high-energy cosmic ray particles

    CERN Document Server

    Marinho, R M; Aguiar, O D; Frajuca, C

    2002-01-01

    High-energy cosmic ray particles are expected to be a significant source of noise in resonant mass gravitational wave detectors close to the quantum limit. The spherical, fourth generation antennas have been designed to attain such a limit. In this work we will show how the energy of a cosmic ray particle interacting with such an antenna is distributed over its eigenmodes. We will then make some comments on the relevant consequences of such a distribution for gravitational wave detection.

  2. Decadal trends in the diurnal variation of galactic cosmic rays observed using neutron monitor data

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Simon [Reading Univ. (United Kingdom). Dept. of Meteorology; Univ. College London, Dorking (United Kingdom). Mullard Space Science Lab.; Owens, Mathew; Lockwood, Mike [Reading Univ. (United Kingdom). Dept. of Meteorology; Owen, Chris [Univ. College London, Dorking (United Kingdom). Mullard Space Science Lab.

    2017-10-01

    The diurnal variation (DV) in galactic cosmic ray (GCR) flux is a widely observed phenomenon in neutron monitor data. The background variation considered primarily in this study is due to the balance between the convection of energetic particles away from the Sun and the inward diffusion of energetic particles along magnetic field lines. However, there are also times of enhanced DV following geomagnetic disturbances caused by coronal mass ejections or corotating interaction regions. In this study we investigate changes in the DV over four solar cycles using ground-based neutron monitors at different magnetic latitudes and longitudes at Earth. We divide all of the hourly neutron monitor data into magnetic polarity cycles to investigate cycle-to-cycle variations in the phase and amplitude of the DV. The results show, in general, a similarity between each of the A<0 cycles and A>0 cycles, but with a phase change between the two. To investigate this further, we split the neutron monitor data by solar magnetic polarity between times when the dominant polarity was either directed outward (positive) or inward (negative) at the northern solar pole. We find that the maxima and minima of the DV changes by, typically, 1-2 h between the two polarity states for all non-polar neutron monitors. This difference between cycles becomes even larger in amplitude and phase with the removal of periods with enhanced DV caused by solar wind transients. The time difference between polarity cycles is found to vary in a 22-year cycle for both the maximum and minimum times of the DV. The times of the maximum and minimum in the DV do not always vary in the same manner between A>0 and A<0 polarity cycles, suggesting a slight change in the anisotropy vector of GCRs arriving at Earth between polarity cycles. Polar neutron monitors show differences in phase between polarity cycles which have asymptotic directions at mid-to-high latitudes. All neutron monitors show changes in the amplitude of the

  3. Badhwar-O'Neill 2011 Galactic Cosmic Ray Model Update and Future Improvements

    Science.gov (United States)

    O'Neill, Pat M.; Kim, Myung-Hee Y.

    2014-01-01

    The Badhwar-O'Neill Galactic Cosmic Ray (GCR) Model based on actual GR measurements is used by deep space mission planners for the certification of micro-electronic systems and the analysis of radiation health risks to astronauts in space missions. The BO GCR Model provides GCR flux in deep space (outside the earth's magnetosphere) for any given time from 1645 to present. The energy spectrum from 50 MeV/n-20 GeV/n is provided for ions from hydrogen to uranium. This work describes the most recent version of the BO GCR model (BO'11). BO'11 determines the GCR flux at a given time applying an empirical time delay function to past sunspot activity. We describe the GCR measurement data used in the BO'11 update - modern data from BESS, PAMELA, CAPRICE, and ACE emphasized for than the older balloon data used for the previous BO model (BO'10). We look at the GCR flux for the last 24 solar minima and show how much greater the flux was for the cycle 24 minimum in 2010. The BO'11 Model uses the traditional, steady-state Fokker-Planck differential equation to account for particle transport in the heliosphere due to diffusion, convection, and adiabatic deceleration. It assumes a radially symmetrical diffusion coefficient derived from magnetic disturbances caused by sunspots carried onward by a constant solar wind. A more complex differential equation is now being tested to account for particle transport in the heliosphere in the next generation BO model. This new model is time-dependent (no longer a steady state model). In the new model, the dynamics and anti-symmetrical features of the actual heliosphere are accounted for so empirical time delay functions will no longer be required. The new model will be capable of simulating the more subtle features of modulation - such as the Sun's polarity and modulation dependence on the gradient and curvature drift. This improvement is expected to significantly improve the fidelity of the BO GCR model. Preliminary results of its

  4. Distinct Pattern of Solar Modulation of Galactic Cosmic Rays above a High Geomagnetic Cutoff Rigidity

    Science.gov (United States)

    Mangeard, Pierre-Simon; Clem, John; Evenson, Paul; Pyle, Roger; Mitthumsiri, Warit; Ruffolo, David; Sáiz, Alejandro; Nutaro, Tanin

    2018-05-01

    Solar modulation refers to Galactic cosmic-ray variations with the ∼11 yr sunspot cycle and ∼22 yr solar magnetic cycle and is relevant to the space radiation environment and effects on Earth’s atmosphere. Its complicated dependence on solar and heliospheric conditions is only roughly understood and has been empirically modeled in terms of a single modulation parameter. Most analyses of solar modulation use neutron monitor (NM) data from locations with relatively low geomagnetic cutoff rigidity, i.e., the threshold for cosmic rays to penetrate Earth’s magnetic field. The Princess Sirindhorn Neutron Monitor at Doi Inthanon, Thailand, has the world’s highest cutoff rigidity (≈17 GV) where observations span a complete solar modulation cycle (since late 2007). The pattern of solar modulation at Doi Inthanon during 2011–2014 was qualitatively very different from that at a low geomagnetic cutoff and is not well described by the same modulation parameter. At other times, NM count rates from Doi Inthanon and McMurdo, Antarctica (cutoff ∼1 GV), were linearly correlated and confirm the observation from latitude surveys in the previous solar cycle that the slope of the correlation changes with solar magnetic polarity. Low solar magnetic tilt angles (magnetic field, which is consistent with an increase in diffusion at high rigidity short-circuiting the effects of drifts and the heliospheric current sheet.

  5. GALACTIC COSMIC-RAY INTENSITY MODULATION BY COROTATING INTERACTION REGION STREAM INTERFACES AT 1 au

    Energy Technology Data Exchange (ETDEWEB)

    Guo, X. [State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing, 100190 (China); Florinski, V. [Center for Space Plasma and Aeronomic Research, University of Alabama, Huntsville, AL 35899 (United States)

    2016-07-20

    We present a new model that couples galactic cosmic-ray (GCR) propagation with magnetic turbulence transport and the MHD background evolution in the heliosphere. The model is applied to the problem of the formation of corotating interaction regions (CIRs) during the last solar minimum from the period between 2007 and 2009. The numerical model simultaneously calculates the large-scale supersonic solar wind properties and its small-scale turbulent content from 0.3 au to the termination shock. Cosmic rays are then transported through the background, and thus computed, with diffusion coefficients derived from the solar wind turbulent properties, using a stochastic Parker approach. Our results demonstrate that GCR variations depend on the ratio of diffusion coefficients in the fast and slow solar winds. Stream interfaces inside the CIRs always lead to depressions of the GCR intensity. On the other hand, heliospheric current sheet (HCS) crossings do not appreciably affect GCR intensities in the model, which is consistent with the two observations under quiet solar wind conditions. Therefore, variations in diffusion coefficients associated with CIR stream interfaces are more important for GCR propagation than the drift effects of the HCS during a negative solar minimum.

  6. GALACTIC COSMIC-RAY INTENSITY MODULATION BY COROTATING INTERACTION REGION STREAM INTERFACES AT 1 au

    International Nuclear Information System (INIS)

    Guo, X.; Florinski, V.

    2016-01-01

    We present a new model that couples galactic cosmic-ray (GCR) propagation with magnetic turbulence transport and the MHD background evolution in the heliosphere. The model is applied to the problem of the formation of corotating interaction regions (CIRs) during the last solar minimum from the period between 2007 and 2009. The numerical model simultaneously calculates the large-scale supersonic solar wind properties and its small-scale turbulent content from 0.3 au to the termination shock. Cosmic rays are then transported through the background, and thus computed, with diffusion coefficients derived from the solar wind turbulent properties, using a stochastic Parker approach. Our results demonstrate that GCR variations depend on the ratio of diffusion coefficients in the fast and slow solar winds. Stream interfaces inside the CIRs always lead to depressions of the GCR intensity. On the other hand, heliospheric current sheet (HCS) crossings do not appreciably affect GCR intensities in the model, which is consistent with the two observations under quiet solar wind conditions. Therefore, variations in diffusion coefficients associated with CIR stream interfaces are more important for GCR propagation than the drift effects of the HCS during a negative solar minimum.

  7. The Large Scale Structure of the Galactic Magnetic Field and High Energy Cosmic Ray Anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez-Muniz, Jaime [Department de Fisica de PartIculas, University de Santiago de Compostela, 15782 Santiago, SPAIN (Spain); Stanev, Todor [Bartol Research Institute, Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716 (United States)

    2006-10-15

    Measurements of the magnetic field in our Galaxy are complex and usually difficult to interpret. A spiral regular field in the disk is favored by observations, however the number of field reversals is still under debate. Measurements of the parity of the field across the Galactic plane are also very difficult due to the presence of the disk field itself. In this work we demonstrate that cosmic ray protons in the energy range 10{sup 18} to 10{sup 19}eV, if accelerated near the center of the Galaxy, are sensitive to the large scale structure of the Galactic Magnetic Field (GMF). In particular if the field is of even parity, and the spiral field is bi-symmetric (BSS), ultra high energy protons will predominantly come from the Southern Galactic hemisphere, and predominantly from the Northern Galactic hemisphere if the field is of even parity and axi-symmetric (ASS). There is no sensitivity to the BSS or ASS configurations if the field is of odd parity.

  8. Effect of energy deposited by cosmic-ray particles on interferometric gravitational wave detectors

    International Nuclear Information System (INIS)

    Yamamoto, Kazuhiro; Hayakawa, Hideaki; Okada, Atsushi; Uchiyama, Takashi; Miyoki, Shinji; Ohashi, Masatake; Kuroda, Kazuaki; Kanda, Nobuyuki; Tatsumi, Daisuke; Tsunesada, Yoshiki

    2008-01-01

    We investigated the noise of interferometric gravitational wave detectors due to heat energy deposited by cosmic-ray particles. We derived a general formula that describes the response of a mirror against a cosmic-ray passage. We found that there are differences in the comic-ray responses (the dependence of temperature and cosmic-ray track position) in cases of interferometric and resonant gravitational wave detectors. The power spectral density of vibrations caused by low-energy secondary muons is 100 times smaller than the goal sensitivity of future second-generation interferometer projects, such as LCGT and Advanced LIGO. The arrival frequency of high-energy cosmic-ray muons that generate enough large showers inside mirrors of LCGT and Advanced LIGO is one per a millennium. We also discuss the probability of exotic-particle detection with interferometers.

  9. Abundances of light isotopes in galactic cosmic rays and the interstellar gas density

    International Nuclear Information System (INIS)

    Westergaard, N.J.

    1979-01-01

    The fluxes of the light isotopes in the galactic cosmic rays are calculated in the energy range from 10 MeV to 5 GeV. The mean amount of matter traversed is taken to increase with decreasing energy, and various forms of the source spectrum are assumed. It is shown that it is possible to reconcile all observed abundance ratios including the low 10 Be abundance found by Garcia-Munoz et al. with an interstellar gas density of 1 atom cm -1 . However, a low value for the adiabatic deceleration in the solor cavity must be assumed. Comparing isotopes of the light elements does not give a unique solution for the deceleration, and it seems to be more profitable to use the isotopes of H and He for this purpose

  10. Astrophysical Li-7 as a product of big bang nucleosynthesis and galactic cosmic-ray spallation

    Science.gov (United States)

    Olive, Keith A.; Schramm, David N.

    1992-01-01

    The astrophysical Li-7 abundance is considered to be largely primordial, while the Be and B abundances are thought to be due to galactic cosmic ray (GCR) spallation reactions on top of a much smaller big bang component. But GCR spallation should also produce Li-7. As a consistency check on the combination of big bang nucleosynthesis and GCR spallation, the Be and B data from a sample of hot population II stars is used to subtract from the measured Li-7 abundance an estimate of the amount generated by GCR spallation for each star in the sample, and then to add to this baseline an estimate of the metallicity-dependent augmentation of Li-7 due to spallation. The singly reduced primordial Li-7 abundance is still consistent with big bang nucleosynthesis, and a single GCR spallation model can fit the Be, B, and corrected Li-7 abundances for all the stars in the sample.

  11. GALACTIC AND EXTRAGALACTIC SUPERNOVA REMNANTS AS SITES OF PARTICLE ACCELERATION

    Directory of Open Access Journals (Sweden)

    Manami Sasaki

    2013-12-01

    Full Text Available Supernova remnants, owing to their strong shock waves, are likely sources of Galactic cosmic rays. Studies of supernova remnants in X-rays and gamma rays provide us with new insights into the acceleration of particles to high energies. This paper reviews the basic physics of supernova remnant shocks and associated particle acceleration and radiation processes. In addition, the study of supernova remnant populations in nearby galaxies and the implications for Galactic cosmic ray distribution are discussed.

  12. Theoretical galactic cosmic ray electron spectrum obtained for sources of varying geometry

    International Nuclear Information System (INIS)

    Cohen, M.E.

    1969-01-01

    Jokipii and Meyer have recently obtained an electron density energy spectrum of the cosmic rays, originating in the Galaxy, using integral solutions of the steady state transfer equations, by considering a circular cylindric galactic disc as source and approximating the resulting fourth order integral. In this report, we present general results, obtained by using an arbitrary circular cylindric source, without restricting ourselves to the galactic disc. The integrals are treated exactly. The conclusions of Jokipii and Meyer form special cases of these results. We also obtain an exponential energy variation which, at the moment, is not observed experimentally. The second part of this work deals with more complicated, but perhaps more realistic models of elliptic cylindric and ellipsoidal galactic disc sources. One may also note that a very large source concentrated in a very small region gives a spectrum not unlike that for a small source distributed throughout a large volume. Finally, it may be remarked that the model adopted is much less restrictive than the artificial conception of 'leakage time' followed by other workers. (author) [fr

  13. GLOBAL GALACTIC DYNAMO DRIVEN BY COSMIC RAYS AND EXPLODING MAGNETIZED STARS

    International Nuclear Information System (INIS)

    Hanasz, Michal; Woltanski, Dominik; Kowalik, Kacper

    2009-01-01

    We report the first results of the first global galactic-scale cosmic ray (CR)-MHD simulations of CR-driven dynamo. We investigate the dynamics of magnetized interstellar medium (ISM), which is dynamically coupled with CR gas. We assume that exploding stars deposit small-scale, randomly oriented, dipolar magnetic fields into the differentially rotating ISM, together with a portion of CRs, accelerated in supernova shocks. We conduct numerical simulations with the aid of a new parallel MHD code PIERNIK. We find that the initial magnetization of galactic disks by exploding magnetized stars forms favorable conditions for the CR-driven dynamo. We demonstrate that dipolar magnetic fields supplied on small supernova remnant scales can be amplified exponentially by the CR-driven dynamo, to the present equipartition values, and transformed simultaneously to large galactic scales. The resulting magnetic field structure in an evolved galaxy appears spiral in the face-on view and reveals the so-called X-shaped structure in the edge-on view.

  14. Recurrent modulation of galactic cosmic ray electrons and protons: Ulysses COSPIN/KET observations

    International Nuclear Information System (INIS)

    Heber, B.; Blake, J.B.; Paizis, C.; Bothmer, V.; Kunow, H.; Wibberenz, G.; Burger, R.A.; Potgieter, M.S.

    2000-01-01

    Since measurements of space probes in the interplanetary space became available it has been known that associated with the occurrence of recurrent fast and slow solar wind streams, forming Corotating Interaction Regions, recurrent variations in the cosmic ray nuclei flux are observed. As pointed out recently by Jokipii and Kota (2) recurrent modulation for positively and negatively charged particles may be different. In the time interval extending from July 1992 to July 1994, Ulysses on its journey to high heliographic latitudes registered ∼20 stable and long-lasting Corotating Interaction Regions (CIRs). In this work we use data from the Cosmic Ray and Solar Particle Investigation Kiel Electron Telescope (COSPIN/KET) instrument on board Ulysses to study the recurrent variation of 2.5 GV electrons and protons. We find that 1) electrons are indeed periodically modulated, but that 2) the periodicity of ∼29 days is longer than the period of ∼26 days for protons, and that 3) the amplitude is larger than the one observed for protons

  15. ACTINIDE AND ULTRA-HEAVY ABUNDANCES IN THE LOCAL GALACTIC COSMIC RAYS: AN ANALYSIS OF THE RESULTS FROM THE LDEF ULTRA-HEAVY COSMIC-RAY EXPERIMENT

    Energy Technology Data Exchange (ETDEWEB)

    Donnelly, J. [Dublin Institute of Technology (DIT), School of Physics, Kevin Street, Dublin 8 (Ireland); Thompson, A.; O' Sullivan, D.; Daly, J.; Drury, L. [School of Cosmic Physics, Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, Dublin 2 (Ireland); Domingo, V.; Wenzel, K.-P. [European Space Research and Technology Centre (ESTEC), Keplerlaan 1, Postbus 299, 2200 AG Noordwijk (Netherlands)

    2012-03-01

    The LDEF Ultra-Heavy Cosmic-Ray Experiment (UHCRE) detected Galactic cosmic rays (GCRs) of charge Z {>=} 70 in Earth orbit with an exposure factor of 170 m{sup 2} sr yr, much larger than any other experiment. The major results include the first statistically significant uniform sample of GCR actinides with 35 events passing quality cuts, evidence for the existence of transuranic nuclei in the GCR with one {sub 96}Cm candidate event, and a low {sub 82}Pb/{sub 78}Pt ratio consistent with other experiments. The probability of the existence of a transuranic component is estimated as 96%, while the most likely {sub 92}U/{sub 90}Th ratio is found to be 0.4 within a wide 70% confidence interval ranging from 0 to 0.96. Overall, the results are consistent with a volatility-based acceleration bias and source material which is mainly ordinary interstellar medium material with some recent contamination by freshly synthesized material. Uncertainty in the key {sub 92}U/{sub 90}Th ratio is dominated by statistical errors resulting from the small sample size and any improved determination will thus require an experiment with a substantially larger exposure factor than the UHCRE.

  16. Galactic cosmic ray gradients, field-aligned and latitudinal, among Voyagers 1/2 and IMP-8

    Science.gov (United States)

    Roelof, E. C.; Decker, R. B.; Krimigis, S. M.; Venkatesan, D.; Lazarus, A. J.

    1982-01-01

    The present investigation represents a summary of a comprehensive analysis of the same subject conducted by Roelof et al. (1981). It is pointed out that the tandem earth-Jupiter trajectories of the Voyager 1/2 spacecraft, combined with baseline measurements from the earth-orbiting IMP 7/8 spacecraft, provide the first opportunity for unambiguously separating latitude from radial or field-aligned effects in galactic cosmic ray gradients. Attention is given to the method of data analysis, and the separation of field-aligned and latitudinal gradients. It is found that latitudinal gradients approximately equal to or greater than 1 percent per deg in the cosmic ray intensity were a common feature of the interplanetary medium between 1 and 5 AU in 1977-78. Except in the most disturbed periods, cosmic ray intensities are well-ordered in field-aligned structures.

  17. Prediction of galactic cosmic ray intensity variation for a few (up to 10-12 years ahead on the basis of convection-diffusion and drift model

    Directory of Open Access Journals (Sweden)

    L. I. Dorman

    2005-11-01

    Full Text Available We determine the dimension of the Heliosphere (modulation region, radial diffusion coefficient and other parameters of convection-diffusion and drift mechanisms of cosmic ray (CR long-term variation, depending on particle energy, the level of solar activity (SA and general solar magnetic field. This important information we obtain on the basis of CR and SA data in the past, taking into account the theory of convection-diffusion and drift global modulation of galactic CR in the Heliosphere. By using these results and the predictions which are regularly published elsewhere of expected SA variation in the near future and prediction of next future SA cycle, we may make a prediction of the expected in the near future long-term cosmic ray intensity variation. We show that by this method we may make a prediction of the expected in the near future (up to 10-12 years, and may be more, in dependence for what period can be made definite prediction of SA galactic cosmic ray intensity variation in the interplanetary space on different distances from the Sun, in the Earth's magnetosphere, and in the atmosphere at different altitudes and latitudes.

  18. Cosmic Ray Acceleration by a Versatile Family of Galactic Wind Termination Shocks

    Energy Technology Data Exchange (ETDEWEB)

    Bustard, Chad; Zweibel, Ellen G. [Physics Department, University of Wisconsin–Madison, 1150 University Avenue, Madison, WI 53706 (United States); Cotter, Cory, E-mail: bustard@wisc.edu [Department of Astronomy, University of Wisconsin–Madison, 2535 Sterling Hall, 475 N. Charter Street, Madison, WI 53706 (United States)

    2017-01-20

    There are two distinct breaks in the cosmic ray (CR) spectrum: the so-called “knee” around 3 × 10{sup 15} eV and the so-called “ankle” around 10{sup 18} eV. Diffusive shock acceleration (DSA) at supernova remnant (SNR) shock fronts is thought to accelerate galactic CRs to energies below the knee, while an extragalactic origin is presumed for CRs with energies beyond the ankle. CRs with energies between 3 × 10{sup 15} and 10{sup 18} eV, which we dub the “shin,” have an unknown origin. It has been proposed that DSA at galactic wind termination shocks, rather than at SNR shocks, may accelerate CRs to these energies. This paper uses the galactic wind model of Bustard et al. to analyze whether galactic wind termination shocks may accelerate CRs to shin energies within a reasonable acceleration time and whether such CRs can subsequently diffuse back to the Galaxy. We argue for acceleration times on the order of 100 Myr rather than a few billion years, as assumed in some previous works, and we discuss prospects for magnetic field amplification at the shock front. Ultimately, we generously assume that the magnetic field is amplified to equipartition. This formalism allows us to obtain analytic formulae, applicable to any wind model, for CR acceleration. Even with generous assumptions, we find that very high wind velocities are required to set up the necessary conditions for acceleration beyond 10{sup 17} eV. We also estimate the luminosities of CRs accelerated by outflow termination shocks, including estimates for the Milky Way wind.

  19. Radiation production and absorption in human spacecraft shielding systems under high charge and energy Galactic Cosmic Rays: Material medium, shielding depth, and byproduct aspects

    Science.gov (United States)

    Barthel, Joseph; Sarigul-Klijn, Nesrin

    2018-03-01

    Deep space missions such as the planned 2025 mission to asteroids require spacecraft shields to protect electronics and humans from adverse effects caused by the space radiation environment, primarily Galactic Cosmic Rays. This paper first reviews the theory on how these rays of charged particles interact with matter, and then presents a simulation for a 500 day Mars flyby mission using a deterministic based computer code. High density polyethylene and aluminum shielding materials at a solar minimum are considered. Plots of effective dose with varying shield depth, charged particle flux, and dose in silicon and human tissue behind shielding are presented.

  20. Superposed epoch study of ICME sub-structures near Earth and their effects on Galactic cosmic rays

    Science.gov (United States)

    Masías-Meza, J. J.; Dasso, S.; Démoulin, P.; Rodriguez, L.; Janvier, M.

    2016-08-01

    Context. Interplanetary coronal mass ejections (ICMEs) are the interplanetary manifestations of solar eruptions. The overtaken solar wind forms a sheath of compressed plasma at the front of ICMEs. Magnetic clouds (MCs) are a subset of ICMEs with specific properties (e.g. the presence of a flux rope). When ICMEs pass near Earth, ground observations indicate that the flux of Galactic cosmic rays (GCRs) decreases. Aims: The main aims of this paper are to find common plasma and magnetic properties of different ICME sub-structures and which ICME properties affect the flux of GCRs near Earth. Methods: We used a superposed epoch method applied to a large set of ICMEs observed in situ by the spacecraft ACE, between 1998 and 2006. We also applied a superposed epoch analysis on GCRs time series observed with the McMurdo neutron monitors. Results: We find that slow MCs at 1 AU have on average more massive sheaths. We conclude that this is because they are more effectively slowed down by drag during their travel from the Sun. Slow MCs also have a more symmetric magnetic field and sheaths expanding similarly as their following MC, while in contrast, fast MCs have an asymmetric magnetic profile and a sheath in compression. In all types of MCs, we find that the proton density and the temperature and the magnetic fluctuations can diffuse within the front of the MC due to 3D reconnection. Finally, we derive a quantitative model that describes the decrease in cosmic rays as a function of the amount of magnetic fluctuations and field strength. Conclusions: The obtained typical profiles of sheath, MC and GCR properties corresponding to slow, middle, and fast ICMEs, can be used for forecasting or modelling these events, and to better understand the transport of energetic particles in ICMEs. They are also useful for improving future operative space weather activities.

  1. On the possibility of galactic cosmic ray-induced radiolysis-powered life in subsurface environments in the Universe.

    Science.gov (United States)

    Atri, Dimitra

    2016-10-01

    Photosynthesis is a mechanism developed by terrestrial life to utilize the energy from photons of solar origin for biological use. Subsurface regions are isolated from the photosphere, and consequently are incapable of utilizing this energy. This opens up the opportunity for life to evolve alternative mechanisms for harvesting available energy. Bacterium Candidatus Desulforudis audaxviator, found 2.8 km deep in a South African mine, harvests energy from radiolysis, induced by particles emitted from radioactive U, Th and K present in surrounding rock. Another radiation source in the subsurface environments is secondary particles generated by galactic cosmic rays (GCRs). Using Monte Carlo simulations, it is shown that it is a steady source of energy comparable to that produced by radioactive substances, and the possibility of a slow metabolizing life flourishing on it cannot be ruled out. Two mechanisms are proposed through which GCR-induced secondary particles can be utilized for biological use in subsurface environments: (i) GCRs injecting energy in the environment through particle-induced radiolysis and (ii) organic synthesis from GCR secondaries interacting with the medium. Laboratory experiments to test these hypotheses are also proposed. Implications of these mechanisms on finding life in the Solar System and elsewhere in the Universe are discussed. © 2016 The Author(s).

  2. Cosmic ray investigation for the Voyager missions; energetic particle studies in the outer heliosphere - and beyond

    Energy Technology Data Exchange (ETDEWEB)

    Stone, E C; Vogt, R E [California Inst. of Tech., Pasadena (USA); McDonald, F B; Teegarden, B J; Trainor, J H [National Aeronautics and Space Administration, Greenbelt, Md. (USA). Goddard Space Flight Center; Jokipii, J R [Arizona Univ., Tucson (USA); Webber, W R [New Hampshire Univ., Durham (USA)

    1977-12-01

    A cosmic-ray detector system (CRS) has been developed for the Voyager mission which will measure the energy spectrum of electrons from approximately 3-110 MeV and the energy spectra and elemental comparison of all cosmic-ray nuclei from hydrogen through iron over an energy range from approximately 1-500 MeV.nuc. Isotopes of hydrogen through sulfur will be resolved from approximately 2-75 MeV/nuc. Studies with CRS data will provide information on the energy content, origin and acceleration process, life history, and dynamics of cosmic rays in the galaxy, and contribute to an understanding of the nucleosynthesis of elements in the cosmic-ray sources. Particular emphasis will be placed on low-energy phenomena that are expected to exist in interstellar space and are known to be present in the outer Solar System. This investigation will also add to our understanding of the transport of cosmic rays, Jovian electrons, and low-energy interplanetary particles over an extended region of interplanetary space. A major contribution to these areas of study will be the measurement of three-dimensional streaming patterns of nuclei from H through Fe and electrons over an extended energy range, with a precision that will allow determination of anisotropies down to 1%. The required combination of charge resolution, reliability and redundance has been achieved with systems consisting entirely of solid-state charged-particle detectors.

  3. A satellite born charged particles telescope for the study of cosmic ray nuclei

    Energy Technology Data Exchange (ETDEWEB)

    De Pascale, M.P. [Rome Univ. `Tor Vergata` (Italy)]|[INFN, Rome (Italy); Bocciolini, M. [Florence Univ. (Italy)]|[INFN, Florence (Italy); Barbiellini, G.; Boezio, M. [Trieste Univ. (Italy)]|[INFN, Trieste (Italy); Bellotti, R.; Cafagna, F. [Bari Univ. (Italy)]|[INFN, Bari (Italy)

    1995-09-01

    The description of the high energy particle telescope NINA for the study of cosmic ray nuclei is presented. The instrument will be installed on board of the Resource 01 satellite and will fly on a polar orbit at 690 Km. The telescope consists on a pile of 16 detecting planes each of them is composed by two silicon strip detectors with perpendicular strips and has a total area of 60x60mm{sup 2}. The experiment goals are the study of cosmic ray protons and nuclei in the energy range 12-100 MeV/amu. It will be sensitive to the anomalous component and will also make the observation of the large solar flare events and geophysical phenomena as well. This experiment is the first step of the program RIM whose goal is the satellite study of anti particles in primary cosmic rays.

  4. MODULATION OF GALACTIC COSMIC RAYS OBSERVED AT L1 IN SOLAR CYCLE 23

    Energy Technology Data Exchange (ETDEWEB)

    Fludra, A., E-mail: Andrzej.Fludra@stfc.ac.uk [RAL Space, STFC Rutherford Appleton Laboratory, Harwell, Didcot OX11 0QX (United Kingdom)

    2015-01-20

    We analyze a unique 15 yr record of galactic cosmic-ray (GCR) measurements made by the SOHO Coronal Diagnostic Spectrometer NIS detectors, recording integrated GCR numbers with energies above 1.0 GeV between 1996 July and 2011 June. We are able to closely reproduce the main features of the SOHO/CDS GCR record using the modulation potential calculated from neutron monitor data by Usoskin et al. The GCR numbers show a clear solar cycle modulation: they decrease by 50% from the 1997 minimum to the 2000 maximum of the solar cycle, then return to the 1997 level in 2007 and continue to rise, in 2009 December reaching a level 25% higher than in 1997. This 25% increase is in contrast with the behavior of Ulysses/KET GCR protons extrapolated to 1 AU in the ecliptic plane, showing the same level in 2008-2009 as in 1997. The GCR numbers are inversely correlated with the tilt angle of the heliospheric current sheet. In particular, the continued increase of SOHO/CDS GCRs from 2007 until 2009 is correlated with the decrease of the minimum tilt angle from 30° in mid-2008 to 5° in late 2009. The GCR level then drops sharply from 2010 January, again consistent with a rapid increase of the tilt angle to over 35°. This shows that the extended 2008 solar minimum was different from the 1997 minimum in terms of the structure of the heliospheric current sheet.

  5. Modulation of Galactic Cosmic Rays in the Inner Heliosphere over Solar Cycles

    Science.gov (United States)

    Shen, Z.-N.; Qin, G.

    2018-02-01

    The 11- and 22-year modulation of galactic cosmic rays (GCRs) in the inner heliosphere is studied using a numerical model developed by Qin and Shen in 2017. Based on the numerical solutions of Parker’s transport equations, the model incorporates a modified Parker heliospheric magnetic field, a locally static time-delayed heliosphere, and a time-dependent diffusion coefficients model in which an analytical expression of the variation of magnetic turbulence magnitude throughout the inner heliosphere is applied. Furthermore, during solar maximum, the solar magnetic polarity is determined randomly with the possibility of A > 0 decided by the percentage of the solar north polar magnetic field being outward and the solar south polar magnetic field being inward. The computed results are compared at various energies with several GCR observations, e.g., the Interplanetary Monitoring Platform 8 (IMP 8), EPHIN on board the Solar and Heliospheric Observatory (SOHO), Ulysses, and Voyager 1 and 2, and they show good agreement. We show that our model has successfully reproduced the 11- and 22-year modulation cycles.

  6. THE ROLE OF COSMIC-RAY PRESSURE IN ACCELERATING GALACTIC OUTFLOWS

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, Christine M.; Pakmor, Rüdiger; Pfrommer, Christoph; Springel, Volker [Heidelberger Institut für Theoretische Studien, Schloss-Wolfsbrunnenweg 35, D-69118 Heidelberg (Germany); Marinacci, Federico [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Glover, Simon C. O. [Zentrum für Astronomie der Universität Heidelberg, ITA, Albert-Ueberle-Str. 2, D-69120 Heidelberg (Germany); Clark, Paul C. [School of Physics and Astronomy, Queen’s Buildings, The Parade, Cardiff University, Cardiff CF24 3AA (United Kingdom); Smith, Rowan J., E-mail: Christine.Simpson@h-its.org [Jodrell Bank Centre for Astrophysics, University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom)

    2016-08-20

    We study the formation of galactic outflows from supernova (SN) explosions with the moving-mesh code AREPO in a stratified column of gas with a surface density similar to the Milky Way disk at the solar circle. We compare different simulation models for SN placement and energy feedback, including cosmic rays (CRs), and find that models that place SNe in dense gas and account for CR diffusion are able to drive outflows with similar mass loading as obtained from a random placement of SNe with no CRs. Despite this similarity, CR-driven outflows differ in several other key properties including their overall clumpiness and velocity. Moreover, the forces driving these outflows originate in different sources of pressure, with the CR diffusion model relying on non-thermal pressure gradients to create an outflow driven by internal pressure and the random-placement model depending on kinetic pressure gradients to propel a ballistic outflow. CRs therefore appear to be non-negligible physics in the formation of outflows from the interstellar medium.

  7. Modulation of Galactic Cosmic Rays in the Inner Heliosphere, Comparing with PAMELA Measurements

    Science.gov (United States)

    Qin, G.; Shen, Z.-N.

    2017-09-01

    We develop a numerical model to study the time-dependent modulation of galactic cosmic rays in the inner heliosphere. In the model, a time-delayed modified Parker heliospheric magnetic field (HMF) and a new diffusion coefficient model, NLGCE-F, from Qin & Zhang, are adopted. In addition, the latitudinal dependence of magnetic turbulence magnitude is assumed to be ˜ (1+{\\sin }2θ )/2 from the observations of Ulysses, and the radial dependence is assumed to be ˜ {r}S, where we choose an expression of S as a function of the heliospheric current sheet tilt angle. We show that the analytical expression used to describe the spatial variation of HMF turbulence magnitude agrees well with the Ulysses, Voyager 1, and Voyager 2 observations. By numerically calculating the modulation code, we get the proton energy spectra as a function of time during the recent solar minimum, it is shown that the modulation results are consistent with the Payload for Antimatter-Matter Exploration and Light-nuclei Astrophysics measurements.

  8. Local Times of Galactic Cosmic Ray Intensity Maximum and Minimum in the Diurnal Variation

    Directory of Open Access Journals (Sweden)

    Su Yeon Oh

    2006-06-01

    Full Text Available The Diurnal variation of galactic cosmic ray (GCR flux intensity observed by the ground Neutron Monitor (NM shows a sinusoidal pattern with the amplitude of 1sim 2 % of daily mean. We carried out a statistical study on tendencies of the local times of GCR intensity daily maximum and minimum. To test the influences of the solar activity and the location (cut-off rigidity on the distribution in the local times of maximum and minimum GCR intensity, we have examined the data of 1996 (solar minimum and 2000 (solar maximum at the low-latitude Haleakala (latitude: 20.72 N, cut-off rigidity: 12.91 GeV and the high-latitude Oulu (latitude: 65.05 N, cut-off rigidity: 0.81 GeV NM stations. The most frequent local times of the GCR intensity daily maximum and minimum come later about 2sim3 hours in the solar activity maximum year 2000 than in the solar activity minimum year 1996. Oulu NM station whose cut-off rigidity is smaller has the most frequent local times of the GCR intensity maximum and minimum later by 2sim3 hours from those of Haleakala station. This feature is more evident at the solar maximum. The phase of the daily variation in GCR is dependent upon the interplanetary magnetic field varying with the solar activity and the cut-off rigidity varying with the geographic latitude.

  9. Galactic cosmic rays in the periods of an inversion of the total solar magnetic field

    International Nuclear Information System (INIS)

    Krajnev, M.B.; Stozhkov, Yu.I.; Charakhch'yan, T.N.

    1984-01-01

    Anomalies in galactic cosmic ray (GCR) behaviour in the periods of the total solar magnetic field (TSMF) inversion are considered according to the data of neutron monitors and stratospheric measurements. These anomalies are interpreted as superpositions of two phenomena: phenomenon 1 and phenomenon 2. Phenomenon 1 is conditioned by the decrease and following strengthening of the regular interplanetary field strong strength in heliosphere in the periods of TSMF inversion. Phenomenon 2 consists in exess of GCR nuclei intensity over the expeited one, corresponding to the level of solar activity after TSMF inversion with dMsub(Z)/dt > 0 (inversion of 1969-1971) and also in decrease of observed GCR nuclei intensity as compared to the expected one after TSMF inversion with dMsub(Z)/dt < 0 (Msub(Z)-projection of magnetic field dipole moment on solar axis of rotation). The phenomenon 1 is slightly late in respect to TSMF inversion, as the phenomenon 2 takes part in the process only approximately 1 year after inversion completing

  10. The dependence of cosmic ray-driven galactic winds on halo mass

    Science.gov (United States)

    Jacob, Svenja; Pakmor, Rüdiger; Simpson, Christine M.; Springel, Volker; Pfrommer, Christoph

    2018-03-01

    Galactic winds regulate star formation in disc galaxies and help to enrich the circum-galactic medium. They are therefore crucial for galaxy formation, but their driving mechanism is still poorly understood. Recent studies have demonstrated that cosmic rays (CRs) can drive outflows if active CR transport is taken into account. Using hydrodynamical simulations of isolated galaxies with virial masses between 1010 and 1013 M⊙, we study how the properties of CR-driven winds depend on halo mass. CRs are treated in a two-fluid approximation and their transport is modelled through isotropic or anisotropic diffusion. We find that CRs are only able to drive mass-loaded winds beyond the virial radius in haloes with masses below 1012 M⊙. For our lowest examined halo mass, the wind is roughly spherical and has velocities of ˜20 km s-1. With increasing halo mass, the wind becomes biconical and can reach 10 times higher velocities. The mass loading factor drops rapidly with virial mass, a dependence that approximately follows a power law with a slope between -1 and -2. This scaling is slightly steeper than observational inferences, and also steeper than commonly used prescriptions for wind feedback in cosmological simulations. The slope is quite robust to variations of the CR injection efficiency or the CR diffusion coefficient. In contrast to the mass loading, the energy loading shows no significant dependence on halo mass. While these scalings are close to successful heuristic models of wind feedback, the CR-driven winds in our present models are not yet powerful enough to fully account for the required feedback strength.

  11. Cosmic ray origin: the way ahead

    International Nuclear Information System (INIS)

    Wolfendale, A W

    2003-01-01

    Despite their discovery being 90 years ago cosmic rays are still characterised by their uncertain masses at high energy and their uncertain origin. This paper deals with the origin problem. The case is put for the majority of the particles being of galactic origin - a generally accepted result. Specific models are put forward for the galactic mechanism and that for the minority extragalactic component

  12. [A research program in neutrino physics, cosmic rays and elementary particles: Tasks A, B, C, D

    International Nuclear Information System (INIS)

    Sobel, H.W.

    1991-01-01

    A Summary of the DOE Supported High Energy Physics Research at The University of California, Irvine. Physics interests of the group are focused primarily on tests of conservation laws and studies of fundamental interactions between particles. There is also a significant interest in astrophysics and cosmic rays. The DOE support has been divided into four tasks briefly describes in this paper

  13. Multi-Scale Model of Galactic Cosmic Ray Effects on the Hippocampus

    Science.gov (United States)

    Cucinotta, Francis

    An important concern for risk assessment from galactic cosmic ray (GCR) exposures is impacts to the central nervous systems including changes in cognition, and associations with increased risk of Alzheimer’s disease (AD). AD, which affects about 50 percent of the population above age 80-yr, is a degenerative disease that worsens with time after initial onset leading to death, and has no known cure. AD is difficult to detect at early stages, and the small number of epidemiology studies that have considered the possibility have not identified an association with low dose radiation. However, experimental studies in transgenic mice suggest the possibility exits. We discuss modeling approaches to consider mechanisms whereby GCR would accelerate the occurrence of AD to earlier ages. Biomarkers of AD include Amyloid beta plaques, and neurofibrillary tangles (NFT) made up of aggregates of the hyper-phosphorylated form of the micro-tubule associated, tau protein. Related markers include synaptic degeneration, dendritic spine loss, and neuronal cell loss through apoptosis. GCR may affect these processes by causing oxidative stress, aberrant signaling following DNA damage, and chronic neuro-inflammation. Cell types considered in multi-scale models are neurons, astrocytes, and microglia. We developed biochemical and cell kinetics models of DNA damage signaling related to glycogen synthase kinase-3 beta and neuro-inflammation, and considered approaches to develop computer simulations of GCR induced cell interactions and their relationships to Amyloid beta plaques and NFTs. Comparison of model results to experimental data for the age specific development of plaques in transgenic mice and predictions of space radiation effects will be discussed.

  14. Cosmic Rays and Non-thermal Emission Induced by Accretion of Cool Gas onto the Galactic Disk

    Science.gov (United States)

    Inoue, Susumu; Uchiyama, Yasunobu; Arakawa, Masanori; Renaud, Matthieu; Wada, Keiichi

    2017-11-01

    On both observational and theoretical grounds, the disk of our Galaxy should be accreting cool gas with temperature ≲ {10}5 K via the halo at a rate ˜1 {{M}⊙ {yr}}-1. At least some of this accretion is mediated by high-velocity clouds (HVCs), observed to be traveling in the halo with velocities of a few 100 km s-1 and occasionally impacting the disk at such velocities, especially in the outer regions of the Galaxy. We address the possibility of particle acceleration in shocks triggered by such HVC accretion events, and the detectability of consequent non-thermal emission in the radio to gamma-ray bands and high-energy neutrinos. For plausible shock velocities ˜ 300 {km} {{{s}}}-1 and magnetic field strengths ˜ 0.3{--}10 μ {{G}}, electrons and protons may be accelerated up to ˜1-10 TeV and ˜ 30{--}{10}3 TeV, respectively, in sufficiently strong adiabatic shocks during their lifetime of ˜ {10}6 {{yr}}. The resultant pion decay and inverse Compton gamma-rays may be the origin of some unidentified Galactic GeV-TeV sources, particularly the “dark” source HESS J1503-582 that is spatially coincident with the anomalous H I structure known as “forbidden-velocity wings.” Correlation of their locations with star-forming regions may be weak, absent, or even opposite. Non-thermal radio and X-ray emission from primary and/or secondary electrons may be detectable with deeper observations. The contribution of HVC accretion to Galactic cosmic rays is subdominant, but could be non-negligible in the outer Galaxy. As the thermal emission induced by HVC accretion is likely difficult to detect, observations of such phenomena may offer a unique perspective on probing gas accretion onto the Milky Way and other galaxies.

  15. Cosmogenic nuclides in recently fallen meteorites: Evidence for galactic cosmic ray variations during the period 1967--1978

    International Nuclear Information System (INIS)

    Evans, J.C.; Reeves, J.H.; Rancitelli, L.A.; Bogard, D.D.

    1982-01-01

    Cosmogenic radionuclides were measured on 48 fragments of 24 meteorites which fell between 1967 and 1978. Nondestructive gamma counting techniques were used to obtain data on 7 Be, 46 Sc, 48 V, 51 Cr, 54 Mn, 56 Co, 57 Co, 58 Co, and 60 Co on at least some of the samples. Sodium 22 and 26 Al measurements are reported on all 48 samples. In addition, new rare gas data and exposure ages are reported for the meteorites Guibga, Gorlovka, Dhajala, Louisville, Acapulco, Jilin, Kabo, Alta-Ameen, and Canon City. The cosmogenic radioisotope and rare gas data are interpreted in terms of a time dependent modulation of galactic cosmic rays spanning one full 11 year sun spot cycle. Special attention is given to the data on 22 Na, 46 Sc, 54 Mn, and 48 V with either 26 Al or 22 Ne/ 21 Ne used to provide a shielding correction. The shielding normalized data using the 26 Al method appear to correlate well with calculated production rates scaled against the Deep River neutron monitor. The data for the four isotopes are consistent with a production rate variation of a factor of 2.5--3 between solar maximum and solar minimum for sun spot cycle 20. These data demonstrate that the production rates of cosmic ray-produced nuclides in meteorites vary considerably according to modulation by the 11-year solar cycle and support the concept that variations of solar-modulated, cosmic ray flux of similar magnitude have occurred over much longer time periods

  16. Galactic cosmic ray spectral index: the case of Forbush decreases of March 2012

    Science.gov (United States)

    Livada, M.; Mavromichalaki, H.; Plainaki, C.

    2018-01-01

    During the burst of solar activity in March 2012, close to the maximum of solar cycle 24, a number of X-class and M-class flares and halo CMEs with velocity up to 2684 km/s were recorded. During a relatively short period (7-21 March 2012) two Forbush decreases were registered in the ground-level neutron monitor data. In this work, after a short description of the solar and geomagnetic background of these Forbush decreases, we deduce the cosmic ray density and anisotropy variations based on the daily cosmic ray data of the neutron monitor network (http://www.nmdb.eu; http://cosray.phys.uoa.gr). Applying to our data two different coupling functions methods, the spectral index of these Forbush decreases was calculated following the technique of Wawrzynczak and Alania (Adv. Space Res. 45:622-631, 2010). We pointed out that the estimated values of the spectral index γ of these events are almost similar for both cases following the fluctuation of the Forbush decrease. The study and the calculation of the cosmic ray spectrum during such cosmic ray events are very important for Space Weather applications.

  17. Impact of cosmic rays and solar energetic particles on the Earth’s ionosphere and atmosphere

    Czech Academy of Sciences Publication Activity Database

    Velinov, P. I. Y.; Asenovski, S.; Kudela, K.; Laštovička, Jan; Mateev, L.; Mishev, A.; Tonev, P.

    2013-01-01

    Roč. 3, 26 March (2013), A14/1-A14/17 ISSN 2115-7251 Grant - others:European COST Action(XE) ES0803 Institutional support: RVO:68378289 Keywords : cosmic rays * solar energetic particles * ionization * ionosphere * atmosphere * solar activity * solar-terrestrial relationships Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 2.519, year: 2013 http://www.swsc-journal.org/articles/swsc/abs/2013/01/swsc120040/swsc120040.html

  18. High energy cosmic rays

    CERN Document Server

    Stanev, Todor

    2010-01-01

    Offers an accessible text and reference (a cosmic-ray manual) for graduate students entering the field and high-energy astrophysicists will find this an accessible cosmic-ray manual Easy to read for the general astronomer, the first part describes the standard model of cosmic rays based on our understanding of modern particle physics. Presents the acceleration scenario in some detail in supernovae explosions as well as in the passage of cosmic rays through the Galaxy. Compares experimental data in the atmosphere as well as underground are compared with theoretical models

  19. High-energy cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Gaisser, Thomas K. [Bartol Research Institute, University of Delaware, Newark, DE 19716 (United States)]. E-mail: gaisser@bartol.udel.edu; Stanev, Todor [Bartol Research Institute, University of Delaware, Newark, DE 19716 (United States)

    2006-10-17

    After a brief review of galactic cosmic rays in the GeV to TeV energy range, we describe some current problems of interest for particles of very high energy. Particularly interesting are two features of the spectrum, the knee above 10{sup 15} eV and the ankle above 10{sup 18} eV. An important question is whether the highest-energy particles are of extra-galactic origin and, if so, at what energy the transition occurs. A theme common to all energy ranges is use of nuclear abundances as a tool for understanding the origin of the cosmic radiation.

  20. A Shifting Shield Provides Protection Against Cosmic Rays

    Science.gov (United States)

    Kohler, Susanna

    2017-12-01

    The Sun plays an important role in protecting us from cosmic rays, energetic particles that pelt us from outside our solar system. But can we predict when and how it will provide the most protection, and use this to minimize the damage to both pilotedand roboticspace missions?The Challenge of Cosmic RaysSpacecraft outside of Earths atmosphere and magnetic field are at risk of damage from cosmic rays. [ESA]Galactic cosmic rays are high-energy, charged particles that originate from astrophysical processes like supernovae or even distant active galactic nuclei outside of our solar system.One reason to care about the cosmic rays arriving near Earth is because these particles can provide a significant challenge for space missions traveling above Earths protective atmosphere and magnetic field. Since impacts from cosmic rays can damage human DNA, this risk poses a major barrier to plans for interplanetary travel by crewed spacecraft. And roboticmissions arent safe either: cosmic rays can flip bits, wreaking havoc on spacecraft electronics as well.The magnetic field carried by the solar wind provides a protective shield, deflecting galactic cosmic rays from our solar system. [Walt Feimer/NASA GSFCs Conceptual Image Lab]Shielded by the SunConveniently, we do have some broader protection against galactic cosmic rays: a built-in shield provided by the Sun. The interplanetary magnetic field, which is embedded in the solar wind, deflects low-energy cosmic rays from us at the outer reaches of our solar system, decreasing the flux of these cosmic rays that reach us at Earth.This shield, however, isnt stationary; instead, it moves and changes as the strength and direction of the solar wind moves and changes. This results in a much lower cosmic-ray flux at Earth when solar activity is high i.e., at the peak of the 11-year solar cycle than when solar activity is low. This visible change in local cosmic-ray flux with solar activity is known as solar modulation of the cosmic ray flux

  1. Primary cosmic ray flux

    Energy Technology Data Exchange (ETDEWEB)

    Stanev, Todor

    2001-05-01

    We discuss the primary cosmic ray flux from the point of view of particle interactions and production of atmospheric neutrinos. The overall normalization of the cosmic ray flux and its time variations and site dependence are major ingredients of the atmospheric neutrino predictions and the basis for the derivation of the neutrino oscillation parameters.

  2. Oscillations in the open solar magnetic flux with a period of 1.68 years: imprint on galactic cosmic rays and implications for heliospheric shielding

    Directory of Open Access Journals (Sweden)

    A. Rouillard

    2004-12-01

    Full Text Available An understanding of how the heliosphere modulates galactic cosmic ray (GCR fluxes and spectra is important, not only for studies of their origin, acceleration and propagation in our galaxy, but also for predicting their effects (on technology and on the Earth's environment and organisms and for interpreting abundances of cosmogenic isotopes in meteorites and terrestrial reservoirs. In contrast to the early interplanetary measurements, there is growing evidence for a dominant role in GCR shielding of the total open magnetic flux, which emerges from the solar atmosphere and enters the heliosphere. In this paper, we relate a strong 1.68-year oscillation in GCR fluxes to a corresponding oscillation in the open solar magnetic flux and infer cosmic-ray propagation paths confirming the predictions of theories in which drift is important in modulating the cosmic ray flux. Key words. Interplanetary physics (Cosmic rays, Interplanetary magnetic fields

  3. Modeling of Cosmic-Ray Propagation and Galactic Diffuse Gamma-Ray Emission in Support of Current and Future NASA Missions, Phase 3

    Science.gov (United States)

    Moskalenko, Igor

    This is a "Phase 3" successor proposal that is a continuation of work funded by the Astrophysics Research and Analysis (APRA) Program through the sub-topic "Particle Astrophysics": Considerable advances in astrophysics of cosmic rays in recent years have become possible due to superior instrumentation launched into space and to the top of the atmosphere. The ACE-CRIS, AMS-02, Fermi-LAT, HAWC, PAMELA, SuperTIGER, Voyager 1,2, WMAP, and many other missions made a lot of breakthroughs and more is expected in the following years. Other high-expectations missions are recently launched (CALET) or are awaiting for launch (ISS-CREAM). The claimed precision of the AMS- 02 data reaches 1-3%. Taking full advantage of the high quality data requires numerical models of comparable accuracy. The current state-of-the-art cosmic ray propagation model is GALPROP, which has become a standard analysis tool in astrophysics of cosmic rays, studies of the diffuse emissions, and related fields. It provides a unified framework for the interpretation of data collected by many different kinds of experiments and emphasizes the inter-relationship between different types of data. We are proposing considerable improvements of the GALPROP model and tool that include generalization of the description of the components of the Galactic interstellar medium to the full 3D and extensive application of the Bayesian tools in building such data-sets, development of a heliospheric propagation tool fully compatible with GALPROP, development of a reliable diffuse emission model in the keV-TeV energy range, generalization of the nuclear reaction network and cross section routines to include trans-iron nuclides, improvements in the description of the production of secondary particles in cosmic ray interactions, various speed and memory optimizations. We will continue to support a dedicated website which hosts GALPROP WebRun, a user-friendly interface for running the GALPROP code on a dedicated cluster

  4. Study of fossil tracks due to 50≤Z≤92 galactic cosmic ray nuclei in meteoritic crystals: Results and perspectives

    International Nuclear Information System (INIS)

    Perelygin, V.P.; Petrova, R.I.; Stetsenko, S.G.; Brandt, R.; Vater, P.; Rebetez, M.; Spohr, R.; Vetter, J.; Perron, C.

    1999-01-01

    A new approach to the problem of investigation of charge and energy spectra of ultra heavy Galactic cosmic ray nuclei, based on fossil track study of extraterrestrial olivine crystals has been developed. The results of an investigation of ultra heavy Galactic cosmic ray nuclei (Z=50-92) in meteoritic olivine crystals are presented. The technique was based on calibration of olivine crystals with accelerated Xe, Au, Pb and U ions and well-controlled partial annealing of 'fresh' and 'fossil' tracks. It allows us to determine the charge spectra and abundances of cosmic ray nuclei based on fossil track length study in meteoritic and Moon crystals. The comparative studies of the spectra of ''fossil' tracks and tracks due to 208 Pb and 238 U nuclei have shown that the group of 210 μm 'fossil' tracks, first observed in 1980 at JINR is due to Th-U nuclei-products of recent r-process nucleosyntesis in our Galaxy. The method in principle allows one to resolve Pt-Pb peaks in fossil tracks, to establish the upper limit of the abundance of Z>110 nuclei in the Galactic cosmic rays at the level ≤10 -3 to the abundance of actinide nuclei and to get information on the history of Z>50 cosmic ray nuclei in time interval up to 220 M.Y

  5. On the equation of transport for cosmic-ray particles in the interplanetary region

    International Nuclear Information System (INIS)

    Webb, G.M.; Gleeson, L.J.

    1979-01-01

    Two new alternative derivations of the equation of transport for cosmic-ray particles in the interplanetary region are provided. Both derivations are carried out by using particle position r and time t in a frame of reference fixed in the solar system, and the particle momentum p' is specified relative to a local frame of reference moving with the solar wind. The first derivation is carried out by writing down a continuity equation for the cosmic rays, taking into account particle streaming and energy changes, and subsequently deriving the streaming and energy change terms in this equation. The momentum change term in the continuity equation, previously considered to be due to the adiabatic deceleration of particles in the expanding magnetic fields carried by the solar wing, appears in the present analysis as a dynamic effect in which the Lorentz force on the particle does not appear explicitly. An alternative derivation based on the ensemble averaged Liouville equation for charged particles in the stochastic interplanetary magnetic field using (r,p',t) as independent coordinates is also given. The latter derivation confirms the momentum change interpretation of the first derivation. A new derivation of the adiabatic rate as a combination of inverse-Fermi and betatron deceleration processes is also provided. (Auth.)

  6. Cosmic rays

    International Nuclear Information System (INIS)

    Tkachev, I.I.

    2014-01-01

    In this talk I will review results of cosmic ray observations at the highest energies. This year the new results on energy spectra, composition and the study of arrival directions of cosmic ray primaries came from the Telescope Array collaboration. I present these results in comparison with measurements done by other recent experiments and discuss their implications for the search of cosmic ray sources. Some related results in gamma-ray astronomy and selected recent advances in theory are also covered. (author)

  7. Erzion interpretation of negative penetrating cosmic ray particles excess flux observed in bubble chamber "SKAT"

    Science.gov (United States)

    Bazhutov, Yu. N.

    2001-08-01

    It is discussed the interpretation of negative penetrating cosmic ray particles excess flux observed in bubble chamber "SKAT" for the momentum range P > P0 = 30 GeV/c by Erzions, hypothetical heavy stable penetrating hadrons, proposed to explain the anomalous vertical muons energy spectrum at small depth underground. Here it is shown that negative charge of p articles observed in "SKAT" is the same as predicted by theoretical Erzion model. The excess particles flux ( J ˜ 10-5 cm-2 s-1 sr-1 ) corresponds to the Erzion intensity observed by scintillation telescope in our previous experiment. The threshold momentum ( P0 ) and the track length threshold ( L0 = 50 cm of liquid BrF3C) are in good accordance with Erzion stop path as for the single charged particle with mass M ≅ 200 GeV/c2 . But to don't contradict with all previous charge ratio results for cosmic ray muons in 30 - 100 GeV/c momentum range it is necessary to propose for such particles the Solar sporadic origin taking to account that both Erzion observations were in the active Sun years (April 23,1979 & July, 1999). INTRODUCTION. 20 years ago to explain anomalous energy spectrum of vertical cosmic ray muons, observed at sea level and small depth underground (particles were started [4,5,6]. Later the theoretical model U(1)xSUl(2)xSU r(2)xSU(3) of such particles (Erzions) has been created in framework of "mirror" models [7,8], which without contradictions to elementary particles Standard Model has explained large kind of another anomalous results in cosmic rays and nuclear physics [9-19]. At last after almost 20 years Erzions search they have been observed due to small vertical original scintillation telescope "Doch-4" [20,21,22]. The observed Erz ions mass was ME = (175+/-25) GeV/c2 and intensity at sea level - JE = (1.8+/-0.4)ṡ10-6 cm-2 sr-1 s-1 (at EE ≤ 6 GeV, PE ≤ 50 GeV/c2 ). To confirm such Erzion discovery it was undertook the attempt of Erzions search on one of the largest bubble chamber (BC

  8. Production of particle clustern in 50 GeV/cπ- -N and cosmic ray interactions

    International Nuclear Information System (INIS)

    Kaul, S.K.

    1977-01-01

    The role of particle clusters in multiple-pion production at accelerator and cosmic ray energies is studied employing the high multiplicity (nsub(c) > = 9) accelerator data at 50 GeV/c, and cosmic ray α-N and N-N data at 0.1-1.21 TeV and 0.25-42.3 TeV respectively. The clusters in individual interactions have been identified by employing three methods. In interactions where the measurement of the secondaries was possible, the parameters of the clusters were found from the kinematics of the cluster production process and in it rest of the cases the parameters were determined by the conventional method. A phenomeological investigation of the following aspects has been made: (i) mass and decay particles of the cluster, (ii) transverse momentum of the cluster, (iii) angular distribution of the secondary particles in the cluster system, and (iv) average momentum (Psub(0)) of the pions in the cluster-rest system. In majority of the events of each type of interactions, at least one cluster is emitted. The average characteristics of clusters produced in double and single cluster events have been found to be similar. The average mass of the cluster and the number of its charged decay particles have been found to be 1.79 +- 0.2 GeV and 5.78 +- 0.4 GeV respectively. Value of (Psub(0)) has been found to be (161.2 +- 12) MeV/c. It has been observed that the features of the clusters at accelerator and cosmic ray energies are almost similar. (author)

  9. Galactic cosmic-ray model in the light of AMS-02 nuclei data

    Science.gov (United States)

    Niu, Jia-Shu; Li, Tianjun

    2018-01-01

    Cosmic ray (CR) physics has entered a precision-driven era. With the latest AMS-02 nuclei data (boron-to-carbon ratio, proton flux, helium flux, and antiproton-to-proton ratio), we perform a global fitting and constrain the primary source and propagation parameters of cosmic rays in the Milky Way by considering 3 schemes with different data sets (with and without p ¯ /p data) and different propagation models (diffusion-reacceleration and diffusion-reacceleration-convection models). We find that the data set with p ¯/p data can remove the degeneracy between the propagation parameters effectively and it favors the model with a very small value of convection (or disfavors the model with convection). The separated injection spectrum parameters are used for proton and other nucleus species, which reveal the different breaks and slopes among them. Moreover, the helium abundance, antiproton production cross sections, and solar modulation are parametrized in our global fitting. Benefited from the self-consistence of the new data set, the fitting results show a little bias, and thus the disadvantages and limitations of the existed propagation models appear. Comparing to the best fit results for the local interstellar spectra (ϕ =0 ) with the VOYAGER-1 data, we find that the primary sources or propagation mechanisms should be different between proton and helium (or other heavier nucleus species). Thus, how to explain these results properly is an interesting and challenging question.

  10. Ultra high energy cosmic rays

    International Nuclear Information System (INIS)

    Watson, A.A.

    1986-01-01

    Cosmic radiation was discovered 70 years ago but its origin remains an open question. The background to this problem is outlined and attempts to discover the origin of the most energetic and rarest group above 10 15 eV are described. Measurements of the energy spectrum and arrival direction pattern of the very highest energy particles, mean energy about 6 x 10 19 eV, are used to argue that these particles originate outside our galaxy. Recent evidence from the new field of ultra high energy γ-ray astronomy are discussed in the context of a galactic origin hypothesis for lower energy cosmic rays. (author)

  11. Evolution of cosmic ray fluxes during the rising phase of solar cycle 23: ULYSSES EPAC and COSPIN/KET observations

    International Nuclear Information System (INIS)

    Heber, B.; Keppler, E.; Blake, J.B.; Fraenz, M.; Kunow, H.

    2000-01-01

    Galactic cosmic rays are entering the heliosphere from the interstellar medium, while anomalous cosmic rays are believed to be pickup ions accelerated at the heliospheric termination shock. Both particle species are modulated by the solar wind and the heliospheric magnetic field. Since 1997 solar activity increased and as a consequence the flux of galactic and anomalous cosmic ray decreased. In this paper we will discuss the variation of low energy anomalous cosmic rays as measured by the Ulysses Energetic Particle Composition Experiment (EPAC) and the Kiel Electron Telescope (KET) on board Ulysses. Specifically we are addressing the question: Are there differences in the modulation of galactic and anomalous cosmic rays and what are possible implication for the modulation of cosmic rays in the heliosphere?

  12. Cosmic-ray acceleration and the radio evolution of Cassiopeia A

    International Nuclear Information System (INIS)

    Chevalier, R.A.; Robertson, J.W.; Scott, J.S.

    1976-01-01

    A more detailed analysis of the Scott and Chevalier model for production of galactic cosmic rays in supernova remnants is presented. Particles are accelerated by second-order Fermi acceleration with turbulent vortices (produced by the motions of the supernova ejecta through the remnant) acting as moving scattering centers. The time-dependent equation of continuity in particle energy space is solved numerically. The results of the calculations are in substantial agreement with all time-dependent observations of the radio emission from Cas A. This mechanism implies an dependent solution yields a cosmic ray spectrum with the same slope as galactic cosmic rays. The results of our calculations and new work on γ-rays by, e.g., Stecker and by Lingenfelter and Higdon and cosmic ray composition by, e.g., Hainebach, Norman, and Schramm support our hypothesis that galactic cosmic rays are produced in supernova remnants by the mechanism proposed by Scott and Chevalier

  13. Electric field of thunderclouds and cosmic rays: evidence for acceleration of particles (runaway electrons)

    CERN Document Server

    Khaerdinov, N S; Petkov, V B; 12th International Conference on Atmospheric Electricity

    2004-01-01

    We present the data on correlations of the intensity of the soft component of cosmic rays with the local electric field of the near-earth atmosphere during thunderstorm periods at the Baksan Valley (North Caucasus, 1700 m a. s. l.). The large-area array for studying the extensive air showers of cosmic rays is used as a particle detector. An electric field meter of the "electric mill" type (rain-protected) is mounted on the roof of the building in the center of this array. The data were obtained in the summer seasons of 2000-2002. We observe strong enhancements of the soft component intensity before some lightning strokes. At the same time, the analysis of the regression curve "intensity versus field" discovers a bump at the field sign that is opposite to the field sign corresponding to acceleration of electrons. It is interpreted as a signature of runaway electrons from the region of the strong field (with opposite sign) overhead.

  14. Observations of galactic cosmic-ray energy spectra between 1 and 9 AU

    International Nuclear Information System (INIS)

    McDonald, F.B.; Lal, N.; Trainor, J.H.; Van Hollebeke, M.A.I.; Webber, W.R.

    1977-01-01

    The variation of the 5--500 MeV per nucleon cosmic-ray helium component has been studied between 1 and 9 AU with essentially identical detector systems on Pioneer 10, Pioneer 11, and Helios I. Between 100 and 200 MeV per nucleon, a radial gradient of 3.3% +- 1.3% per AU is found. At 15 MeV per nucleon, this value increases to 20% +- 4% per AU. Between 4 and 9 AU a well-defined intensity maximum is observed at approx.17 MeV per nucleon. The average adiabatic energy loss between 1 and 9 AU is approx.4 MeV per nucleon per AU. In the inner solar system between 1 and 4 AU this value increases to 7 MeV per nucleon. The observed radial variation between 1 and 9 AU is well described by the Gleeson-Axford force-field solution of the modulation equations over an enrgy range extending from 15 to 500 MeV per nucleon and is in good agreement with the results reported by other Pioneer experiments. These values are much smaller than had been theoretically predicted. The data can be interpreted either in terms of large residual modulation with phi (1 AU) approx. =320 MV and with a modulation region which extends to 50--100 AU or with a significantly reduced modulation parameter of approx.150 MV. These values appear to represent reasonable upper and lower limits on the residual modulation for this period. For the lower limit of phi (1 AU) =150 MV, the low-energy helium component can originate outside the heliosphere, while for phi (1 AU) =320 MV, an interplanetary origin appears most probable

  15. Cosmic rays, clouds and climate

    Energy Technology Data Exchange (ETDEWEB)

    Svensmark, Henrik [Danish Space Research Institute, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark)

    2007-07-01

    Changes in the intensity of galactic cosmic rays seems alter the Earth's cloudiness. A recent experiment has shown how electrons liberated by cosmic rays assist in making aerosols, the building blocks of cloud condensation nuclei, while anomalous climatic trends in Antarctica confirm the role of clouds in helping to drive climate change. Variations in the cosmic-ray influx due to solar magnetic activity account well for climatic fluctuations on decadal, centennial and millennial timescales. Over longer intervals, the changing galactic environment of the Solar System has had dramatic consequences, including Snowball Earth episodes.

  16. TRANSIENT GALACTIC COSMIC-RAY MODULATION DURING SOLAR CYCLE 24: A COMPARATIVE STUDY OF TWO PROMINENT FORBUSH DECREASE EVENTS

    International Nuclear Information System (INIS)

    Zhao, L.-L.; Zhang, H.

    2016-01-01

    Forbush decrease (FD) events are of great interest for transient galactic cosmic-ray (GCR) modulation study. In this study, we perform comparative analysis of two prominent Forbush events during cycle 24, occurring on 2012 March 8 (Event 1) and 2015 June 22 (Event 2), utilizing the measurements from the worldwide neutron monitor (NM) network. Despite their comparable magnitudes, the two Forbush events are distinctly different in terms of evolving GCR energy spectrum and energy dependence of the recovery time. The recovery time of Event 1 is strongly dependent on the median energy, compared to the nearly constant recovery time of Event 2 over the studied energy range. Additionally, while the evolutions of the energy spectra during the two FD events exhibit similar variation patterns, the spectrum of Event 2 is significantly harder, especially at the time of deepest depression. These difference are essentially related to their associated solar wind disturbances. Event 1 is associated with a complicated shock-associated interplanetary coronal mass ejection (ICME) disturbance with large radial extent, probably formed by the merging of multiple shocks and transient flows, and which delivered a glancing blow to Earth. Conversely, Event 2 is accompanied by a relatively simple halo ICME with small radial extent that hit Earth more head-on.

  17. Galactic cosmic ray gradients, field-aligned and latitudinal, among Voyagers 1/2 and IMP-8

    International Nuclear Information System (INIS)

    Roelof, E.C.; Decker, R.B.; Krimigis, S.M.; Venkatesan, D.; Lazarus, A.J.

    1982-01-01

    The tandem Earth-Jupiter trajectories of the Voyager 1/2 spacecraft, combined with baseline measurements from the earth-orbiting IMP-7/8 spacecraft, provide the first opportunity for unambiguously separating latitude from radial or field-aligned effects in galactic cosmic ray gradients. Anti-coincidence solid-state detectors on the Voyager 1/2 LECP experiment measure nucleons > or approximately 20 MeV/nuc with large (28 cm 2 ) omnidirectional geometry factors. Anti-coincidence scintillators on the IMP-7/8 CPME with omnidirectional geometry factors comparable to those on Voyager measure nucleons > or approximately 35 MeV/nuc. Because the Voyagers are well-connected via the interplanetary magnetic field (IMF) to the near-Earth vicinity throughout their transit from 1-5 AU (September 1977 - February 1979), we obtained the first direct measurement of field-aligned gradients, i.e., those that do not depend upon ''corotation'' from one spacecraft to another over many days. Another new result is the unambiguous identification of nonuniform latitudinal gradients approximately 2-5% degree -1 in structures lasting 10-30 days. There is additional evidence for somewhat smaller latitudinal gradients, north to south and probably mixed with small field-aligned gradients -1 , which persist for several solar rotations

  18. Northern Sky Galactic Cosmic Ray Anisotropy between 10 and 1000 TeV with the Tibet Air Shower Array

    Energy Technology Data Exchange (ETDEWEB)

    Amenomori, M. [Department of Physics, Hirosaki University, Hirosaki 036-8561 (Japan); Bi, X. J.; Chen, W. Y.; Ding, L. K.; Feng, Zhaoyang; Gou, Q. B.; Guo, Y. Q.; He, H. H.; Hu, H. B.; Huang, J. [Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Chen, D. [National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Chen, T. L.; Danzengluobu; Hu, Haibing [Department of Mathematics and Physics, Tibet University, Lhasa 850000 (China); Cui, S. W.; He, Z. T. [Department of Physics, Hebei Normal University, Shijiazhuang 050016 (China); Feng, C. F. [Department of Physics, Shandong University, Jinan 250100 (China); Feng, Z. Y. [Institute of Modern Physics, Southwest Jiaotong University, Chengdu 610031 (China); Hibino, K. [Faculty of Engineering, Kanagawa University, Yokohama 221-8686 (Japan); Hotta, N. [Faculty of Education, Utsunomiya University, Utsunomiya 321-8505 (Japan); Collaboration: Tibet AS γ Collaboration; and others

    2017-02-20

    We report on the analysis of the 10–1000 TeV large-scale sidereal anisotropy of Galactic cosmic rays (GCRs) with the data collected by the Tibet Air Shower Array from 1995 October to 2010 February. In this analysis, we improve the energy estimate and extend the decl. range down to −30°. We find that the anisotropy maps above 100 TeV are distinct from that at a multi-TeV band. The so-called tail-in and loss-cone features identified at low energies get less significant, and a new component appears at ∼100 TeV. The spatial distribution of the GCR intensity with an excess (7.2 σ pre-trial, 5.2 σ post-trial) and a deficit (−5.8 σ pre-trial) are observed in the 300 TeV anisotropy map, in close agreement with IceCube’s results at 400 TeV. Combining the Tibet results in the northern sky with IceCube’s results in the southern sky, we establish a full-sky picture of the anisotropy in hundreds of TeV band. We further find that the amplitude of the first order anisotropy increases sharply above ∼100 TeV, indicating a new component of the anisotropy. All these results may shed new light on understanding the origin and propagation of GCRs.

  19. TRANSIENT GALACTIC COSMIC-RAY MODULATION DURING SOLAR CYCLE 24: A COMPARATIVE STUDY OF TWO PROMINENT FORBUSH DECREASE EVENTS

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, L.-L.; Zhang, H., E-mail: zhaolingling@ucas.edu.cn [Key Laboratory of Computational Geodynamics, University of Chinese Academy of Sciences, Beijing 100049 (China)

    2016-08-10

    Forbush decrease (FD) events are of great interest for transient galactic cosmic-ray (GCR) modulation study. In this study, we perform comparative analysis of two prominent Forbush events during cycle 24, occurring on 2012 March 8 (Event 1) and 2015 June 22 (Event 2), utilizing the measurements from the worldwide neutron monitor (NM) network. Despite their comparable magnitudes, the two Forbush events are distinctly different in terms of evolving GCR energy spectrum and energy dependence of the recovery time. The recovery time of Event 1 is strongly dependent on the median energy, compared to the nearly constant recovery time of Event 2 over the studied energy range. Additionally, while the evolutions of the energy spectra during the two FD events exhibit similar variation patterns, the spectrum of Event 2 is significantly harder, especially at the time of deepest depression. These difference are essentially related to their associated solar wind disturbances. Event 1 is associated with a complicated shock-associated interplanetary coronal mass ejection (ICME) disturbance with large radial extent, probably formed by the merging of multiple shocks and transient flows, and which delivered a glancing blow to Earth. Conversely, Event 2 is accompanied by a relatively simple halo ICME with small radial extent that hit Earth more head-on.

  20. Observation of cosmic-ray particles with artificial satellites in Japan

    International Nuclear Information System (INIS)

    Nagata, Katsuaki

    1981-01-01

    The present status are described on the cosmic-ray observation with artificial satellites in Japan. In 1978, an electrostatic analyzer was loaded on the satellite EXOS-A to measure low energy electrons. The spectra taken on April 27, 1978, showed that the electron flux decreased exponentially with the increasing electron energy. A space environment monitor (SEM) was loaded on a geostationary meteorological satellite (GMS) in 1977. The SEM consists of 5 Si detectors, with which particle identification can be made, and protons with the energy of 500 MeV and alpha particles with the energy of 370 MeV were observed. The time variation of particle flux was large in the low energy part and small in the high energy part. In 1984, the satellite EXOS-C will be launched. The purposes of this project are general observation of the middle atmosphere composition and the study of the anomaly of the ionosphere above the Brazilian Anomaly. Measurement of low energy particles will be done with an electrostatic analyzer, and that of high energy particles with a telescope with Si detectors. Other projects designed in Japan are OPEN-J and EXOS-D. (Kato, T.)

  1. All-particle cosmic ray energy spectrum measured by the HAWC experiment from 10 to 500 TeV

    Science.gov (United States)

    Alfaro, R.; Alvarez, C.; Álvarez, J. D.; Arceo, R.; Arteaga-Velázquez, J. C.; Avila Rojas, D.; Ayala Solares, H. A.; Barber, A. S.; Becerril, A.; Belmont-Moreno, E.; BenZvi, S. Y.; Brisbois, C.; Caballero-Mora, K. S.; Capistrán, T.; Carramiñana, A.; Casanova, S.; Castillo, M.; Cotti, U.; Cotzomi, J.; Coutiño de León, S.; De León, C.; De la Fuente, E.; Diaz Hernandez, R.; Dichiara, S.; Dingus, B. L.; DuVernois, M. A.; Díaz-Vélez, J. C.; Ellsworth, R. W.; Enriquez-Rivera, O.; Fiorino, D. W.; Fleischhack, H.; Fraija, N.; García-González, J. A.; González Muñoz, A.; González, M. M.; Goodman, J. A.; Hampel-Arias, Z.; Harding, J. P.; Hernandez-Almada, A.; Hinton, J.; Hueyotl-Zahuantitla, F.; Hui, C. M.; Hüntemeyer, P.; Iriarte, A.; Jardin-Blicq, A.; Joshi, V.; Kaufmann, S.; Lara, A.; Lauer, R. J.; Lennarz, D.; León Vargas, H.; Linnemann, J. T.; Longinotti, A. L.; Luis Raya, G.; Luna-García, R.; López-Cámara, D.; López-Coto, R.; Malone, K.; Marinelli, S. S.; Martinez, O.; Martinez-Castellanos, I.; Martínez-Castro, J.; Martínez-Huerta, H.; Matthews, J. A.; Miranda-Romagnoli, P.; Moreno, E.; Mostafá, M.; Nellen, L.; Newbold, M.; Nisa, M. U.; Noriega-Papaqui, R.; Pelayo, R.; Pretz, J.; Pérez-Pérez, E. G.; Ren, Z.; Rho, C. D.; Rivière, C.; Rosa-González, D.; Rosenberg, M.; Ruiz-Velasco, E.; Salesa Greus, F.; Sandoval, A.; Schneider, M.; Schoorlemmer, H.; Sinnis, G.; Smith, A. J.; Springer, R. W.; Surajbali, P.; Taboada, I.; Tibolla, O.; Tollefson, K.; Torres, I.; Ukwatta, T. N.; Villaseñor, L.; Weisgarber, T.; Westerhoff, S.; Wood, J.; Yapici, T.; Zepeda, A.; Zhou, H.; HAWC Collaboration

    2017-12-01

    We report on the measurement of the all-particle cosmic ray energy spectrum with the High Altitude Water Cherenkov (HAWC) Observatory in the energy range 10 to 500 TeV. HAWC is a ground-based air-shower array deployed on the slopes of Volcan Sierra Negra in the state of Puebla, Mexico, and is sensitive to gamma rays and cosmic rays at TeV energies. The data used in this work were taken over 234 days between June 2016 and February 2017. The primary cosmic-ray energy is determined with a maximum likelihood approach using the particle density as a function of distance to the shower core. Introducing quality cuts to isolate events with shower cores landing on the array, the reconstructed energy distribution is unfolded iteratively. The measured all-particle spectrum is consistent with a broken power law with an index of -2.49 ±0.01 prior to a break at (45.7 ±0.1 ) TeV , followed by an index of -2.71 ±0.01 . The spectrum also represents a single measurement that spans the energy range between direct detection and ground-based experiments. As a verification of the detector response, the energy scale and angular resolution are validated by observation of the cosmic ray Moon shadow's dependence on energy.

  2. Cosmic rays in space

    International Nuclear Information System (INIS)

    Fujitaka, Kazunobu

    2005-01-01

    Cosmos is a mysterious space by which many researchers are fascinated for many years. But, going into space means that we will receive extra exposure due to existence of cosmic rays. Cosmic rays are mainly composed of highly energetic protons. It was born in the last stage of stellar life. Understanding of cosmos will certainly bring right understanding of radiation energy, or energy itself. As no one could see the very early stage of cosmic rays, there is only a speculation. But it is better to speculate something based on certain side evidences, than to give up the whole. Such attitude shall be welcomed in the space researches. Anyway, cosmic rays were born in the last explosion of a star, which is called as Super Nova. After cosmic rays are emitted from the Super Nova, it will reach to the human surroundings. To indicate its intensity, special unit of ''dose rate'' is used. When a man climbs a mountain, cosmic ray intensity surely increases. It doubles as he goes up every 1500m elevation. It was ascertained by our own measurements. Then what happens when the goes up more? At aviation altitude, where airplanes fly, the dose rate will be increased up to 100times the high mountain cases. And what is expected when he goes up further more, up to space orbit altitude? In this case, the dose rate increases up to 10times the airplane cases. Geomagnetism affects the dose rate very much. As primary cosmic ray particles are charged particles, they cannot do well with existence of the magnetic field. In effect, cosmic rays can penetrate into the polar atmosphere along geomagnetic lines of forces which stand almost vertical, but penetration of low energy cosmic rays will be banned when they intend to penetrate crossing the geomagnetic lines of forces in equatorial region. Therefore, exposure due to cosmic rays will become large in polar region, while it remains small in equatorial region. In effect, airplanes which fly over the equator. Only, we have to know that the cosmos

  3. The charged particle veto system of the cosmic ray electron synchrotron telescope

    Science.gov (United States)

    Geske, Matthew T.

    The Cosmic Ray Electron Synchrotron Telescope is a balloon-borne detector designed to measure cosmic electrons at energies from 2 to 50 TeV. CREST completed a successful 10-day Antarctic flight which launched on December 25, 2011. CREST utilizes a novel detection method, searching for the synchrotron radiation emitted by the interaction of TeV-energy electrons with the geomagnetic field. The main detector component for CREST is a 32 x 32 square array of BaF 2 crystal detectors coupled to photomultiplier tubes, with an inter-crystal spacing of 7.5 cm. This document describes the design, construction and flight of the CREST experiment. A special focus is put upon the charged particle veto system, and its use in the analysis of the CREST results. The veto system, consisting of a series of 27 large slabs of organic plastic scintillator read out through photomultiplier tubes, is designed as a passive mechanism for rejecting charged particle events that could contaminate the X-ray signal from synchrotron radiation. The CREST veto system has 99.15% geometric coverage, with individual detector components exhibiting a mean detection efficiency of 99.7%. In whole, the veto system provides a charged particle rejection factor of better than 7 x 103.

  4. Plastic scintillators in coincidence for the study of multi-particle production of sea level cosmic rays in dense medium

    Science.gov (United States)

    Chuang, L. S.; Chan, K. W.; Wada, M.

    1985-01-01

    Cosmic ray particles at sea level penetrate a thick layer of dense medium without appreciable interaction. These penetrating particles are identified with muons. The only appreciable interaction of muons are by knock on processes. A muon may have single, double or any number of knock on with atoms of the material so that one, two, three or more particles will come out from the medium in which the knock on processes occur. The probability of multiparticle production is expected to decrease with the increase of multiplicity. Measurements of the single, double, and triple particles generated in a dense medium (Fe and Al) by sea level cosmic rays at 22.42 N. Lat. and 114.20 E. Long. (Hong Kong) are presented using a detector composed of two plastic scintillators connected in coincidence.

  5. New Measurements of Suprathermal Ions, Energetic Particles, and Cosmic Rays in the Outer Heliosphere from the New Horizons PEPSSI Instrument

    Science.gov (United States)

    Hill, M. E.; Kollmann, P.; McNutt, R. L., Jr.; Stern, A.; Weaver, H. A., Jr.; Young, L. A.; Olkin, C.; Spencer, J. R.

    2017-12-01

    During the period from January 2012 to December 2017 the New Horizons spacecraft traveled from 22 to 41 AU from the Sun, making nearly continuous interplanetary plasma and particle measurements utilizing the SWAP and PEPSSI instruments. We report on newly extended measurements from PEPSSI (Pluto Energetic Particle Spectrometer Science Investigation) that now bring together suprathermal particles above 2 keV/nuc (including interstellar pickup ions), energetic particles with H, He, and O composition from 30 keV to 1 MeV, and cosmic rays above 65 MeV (with effective count-rate-limited upper energy of 1 GeV). Such a wide energy range allows us to look at the solar wind structures passing over the spacecraft, the energetic particles that are often accelerated by these structures, and the suppression of cosmic rays resulting from the increased turbulence inhibiting cosmic ray transport to the spacecraft position (i.e., Forbush decreases). This broad perspective provides simultaneous, previously unattainable diagnostics of outer heliospheric particle dynamics and acceleration. Besides the benefit of being recent, in-ecliptic measurements, unlike the historic Voyager 1 and 2 spacecraft, these PEPSSI observations are also totally unique in the suprathermal range; in this region only PEPSSI can span the suprathermal range, detecting a population that is a linchpin to understanding the outer heliosphere.

  6. Cosmic ray investigations

    International Nuclear Information System (INIS)

    Zatsepin, Georgii T; Roganova, Tat'yana M

    2009-01-01

    The history of cosmic ray research at the Lebedev Institute beginning with the first work and continuing up to now is reviewed. The milestones and main avenues of research are outlined. Pioneering studies on the nuclear cascade process in extensive air showers, investigations of the Vavilov-Cherenkov radiation, and some work on the origin of cosmic rays are discussed. Recent data on ultrahigh-energy particle detection at the Pierre Auger Observatory and the High Resolution Fly's Eye (HiRes) experiments are presented. (conferences and symposia)

  7. Galactic cosmic-ray-produced radionuclides in Antarctic meteorites and a lunar core

    International Nuclear Information System (INIS)

    Fox, R.L.

    1987-01-01

    Radionuclide depth effects in a meteorite, the history and pairing of Antarctic meteorites and processes on the lunar surface are discussed in six chapters. A depth profile of 26 Al, 10 Be and 53 Mn activities have been measured in eleven metal phase samples of the Antarctic meteorite ALHA78084 to determine the importance of the secondary cascade in producing these nuclides in a 30 centimeter diameter meteorite. The results show a buildup of lower energy reaction products and a flat profile for high energy reaction products with depth. The activity of 53 Mn has been measured as a function of depth in eleven soil samples from the lunar double drive tubes 15011/15010. The results agree within error with the previous results of Nishiizumi. These data are consistent with the previously published 26 Al results of the Battelle Northwest group which indicated a disturbed profile down to 17 g/cm 2 and an accumulation rate of 2 cm/My. Comparison with the gardening models of Arnold and Langevin and the local topography suggests such a continuous accumulation is the result of steady downslope transport of surface soil for 7 to 10 My at this site. The 53 Mn activity was determined in eleven samples in eight Allan Hills-80 Antarctic meteorites and one sample from an Elephant Moraine Antarctic meteorite. Mineralogic and field relation data suggest that Allan Hills meteorites to be two sets of paired falls. The 53 Mn results are consistent with the grouping of these meteorites as paired falls excluding the meteorite ALHA80127. comparison with future nuclear particle track work and results from the measurement of other cosmogenic nuclides will provide more definitive results

  8. Multifactorial and microdosimetrical analysis of the biological influence of galactic cosmic rays on Bacillus subtilis spores in the biostack experiment

    International Nuclear Information System (INIS)

    Facius, R.

    1981-01-01

    In this paper a partial experiment is presented which has been performed during several years and several space flight missions. This experiment is part of a research program to study the radiation biological - and in particular the medical relevance of the 'hard' cosmic ray component. The identification of particles (Z, LET, E) was not hindered by the combination with biological objects and could be performed with sufficient accuracy. Refering to semi-empirical findings the distribution of LET values in the bacillus subtilis could be determined in agreement with other experimental results. The localisation and correlation of particle tracks with the individual cells of the target regions is significant. As a result the LET does not seem to be an important parameter for the biological activity within the parameter range studied here. The energy deposition in the spores by delta-electrons could be calculated on the basis of a microdosimetrical analysis. A more detailed analysis was essentially hampered by an insufficient accuracy for the measurement of the distance between particle tracks and the spores. Thus a dose-survival-curve could not be established. In spite of that the relative biological activity (RBW) has been estimated on the basis of density distributions. The failure of these experiments, a review of the relevant literature, and a detailed discussion contribute essentially to the problem of the existence of specific mechanisms for heavy ions and their radiation biological activity. According to the actual knowledge the existence of such a mechanism in addition to delta-electrons has to be considered as most probable. (orig./MG) [de

  9. Cosmic Rays from the Knee to the Ankle

    Science.gov (United States)

    Haungs, Andreas

    Investigations of the energy spectrum as well as the mass composition of cosmic rays in the energy range of PeV to EeV are important for understanding both, the origin of the galactic and the extragalactic cosmic rays. Recently, three modern experimental installations (KASCADE-Grande, IceTop, Tunka-133), dedicated to investigate this primary energy range, have published new results on the all-particle energy spectrum. In this short review these results are presented and the similarities and differences discussed. In addition, the effects of using different hadronic interaction models for interpreting the measured air-shower data will be examined. Finally, a brief discussion on the question if the present results are in agreement or in contradiction with astrophysical models for the transition from galactic to extragalactic origin of cosmic rays completes this paper.

  10. LHCf-measurement of forward neutral particle production for cosmic ray research

    CERN Multimedia

    Masuda, K; Ito, Y; Adriani, O; Papini, P; Tricomi, A; Perrot, A; Ricciarini, S B; D'alessandro, R; Yoshida, K

    2007-01-01

    An energy calibration experiment is under preparation for ultra high energy cosmic ray experiments in the energy range between 1017eV and 1020eV. Small calorimeters will be installed between the two beam pipes in the â€ワY vacuum chamber” 140m away from the interaction point IP1 of the Large Hadron Collider. Within an exposure time of a few hours at luminosity ~10$^{29}$ cm-2s-1, very important results will be obtained that will resolve long standing quests by the highest energy cosmic ray physics experiments.

  11. Structure formation cosmic rays: Identifying observational constraints

    Directory of Open Access Journals (Sweden)

    Prodanović T.

    2005-01-01

    Full Text Available Shocks that arise from baryonic in-fall and merger events during the structure formation are believed to be a source of cosmic rays. These "structure formation cosmic rays" (SFCRs would essentially be primordial in composition, namely, mostly made of protons and alpha particles. However, very little is known about this population of cosmic rays. One way to test the level of its presence is to look at the products of hadronic reactions between SFCRs and the ISM. A perfect probe of these reactions would be Li. The rare isotope Li is produced only by cosmic rays, dominantly in αα → 6Li fusion reactions with the ISM helium. Consequently, this nuclide provides a unique diagnostic of the history of cosmic rays. Exactly because of this unique property is Li affected most by the presence of an additional cosmic ray population. In turn, this could have profound consequences for the Big-Bang nucleosynthesis: cosmic rays created during cosmic structure formation would lead to pre-Galactic Li production, which would act as a "contaminant" to the primordial 7Li content of metalpoor halo stars. Given the already existing problem of establishing the concordance between Li observed in halo stars and primordial 7Li as predicted by the WMAP, it is crucial to set limits to the level of this "contamination". However, the history of SFCRs is not very well known. Thus we propose a few model-independent ways of testing the SFCR species and their history, as well as the existing lithium problem: 1 we establish the connection between gamma-ray and Li production, which enables us to place constraints on the SFCR-made lithium by using the observed Extragalactic Gamma-Ray Background (EGRB; 2 we propose a new site for testing the primordial and SFCR-made lithium, namely, low-metalicity High-Velocity Clouds (HVCs, which retain the pre-Galactic composition without any significant depletion. Although using one method alone may not give us strong constraints, using them in

  12. Interpreting the cosmic ray composition

    International Nuclear Information System (INIS)

    O'C Drury, L.; Ellisson, D.C; Meyer, J.-P.

    2000-01-01

    The detailed pattern of elemental abundances in the Galactic Cosmic Rays is well determined at energies of a few GeV per nucleon. After correction for propagation effects the inferred source composition shows significant deviations from the standard pattern of Galactic elemental abundances. These deviations, surprisingly overabundances of the heavy elements relative to Hydrogen, are clearly a significant clue to the origin of the cosmic rays, but one which has proven very difficult to interpret. We have recently shown that the 'standard' model for the origin of the bulk of the Galactic cosmic rays, namely acceleration by the diffusive shock acceleration process at the strong shocks associated with supernova remnants, can quantitatively explain all features of the source composition if the acceleration occurs from a dusty interstellar medium. This success must be regarded as one of the stronger pieces of evidence in favour of the standard model

  13. Interpreting the cosmic ray composition

    Energy Technology Data Exchange (ETDEWEB)

    O' C Drury, L.; Ellisson, D.C; Meyer, J.-P

    2000-01-31

    The detailed pattern of elemental abundances in the Galactic Cosmic Rays is well determined at energies of a few GeV per nucleon. After correction for propagation effects the inferred source composition shows significant deviations from the standard pattern of Galactic elemental abundances. These deviations, surprisingly overabundances of the heavy elements relative to Hydrogen, are clearly a significant clue to the origin of the cosmic rays, but one which has proven very difficult to interpret. We have recently shown that the 'standard' model for the origin of the bulk of the Galactic cosmic rays, namely acceleration by the diffusive shock acceleration process at the strong shocks associated with supernova remnants, can quantitatively explain all features of the source composition if the acceleration occurs from a dusty interstellar medium. This success must be regarded as one of the stronger pieces of evidence in favour of the standard model.

  14. Cosmic ray observations deep underground and further analysis of the evidence for the production of new particles

    International Nuclear Information System (INIS)

    Krishnaswamy, M.R.; Menon, M.G.K.; Narasimham, V.S.; Ito, N.; Kawakami, S.; Miyake, S.

    1976-01-01

    In a cosmic ray experiment at a depth of 7000 kg/cm 2 three clear new particle events are found, out of a total of 17 events, in which the zenith angle of the penetrating particles is greater than 50 0 , and which have so far been identified as arising from neutrino interactions. The new heavy particles, charged or neutral, must have had low momenta to be consistent which the large opening angles of their decay products. There exists so far no observation of these Kolar events in accelerator experiments with neutrinos. (BJ) [de

  15. Cosmic Ray Mass Measurements with LOFAR

    Directory of Open Access Journals (Sweden)

    Buitink Stijn

    2017-01-01

    Full Text Available In the dense core of LOFAR individual air showers are detected by hundreds of dipole antennas simultaneously. We reconstruct Xmax by using a hybrid technique that combines a two-dimensional fit of the radio profile to CoREAS simulations and a one-dimensional fit of the particle density distribution. For high-quality detections, the statistical uncertainty on Xmax is smaller than 20 g/cm2. We present results of cosmic-ray mass analysis in the energy regime of 1017 - 1017.5 eV. This range is of particular interest as it may harbor the transition from a Galactic to an extragalactic origin of cosmic rays.

  16. Interplanetary cosmic-ray scintillations

    Energy Technology Data Exchange (ETDEWEB)

    Toptygin, I N; Vasiliev, V N [Kalininskij Sel' skokhozyajstvennyj Inst. (USSR)

    1977-05-01

    The equation for the two-particles cosmic-ray distribution function is derived by means of the Boltzmann kinetic equation averaging. This equation is valid for arbitrary ratio of regular and random parts of the magnetic field. For small energy particles the guiding-center approximation is used. On the basis of the derived equation the dependence between power spectra of cosmic-ray intensity and random magnetic field is obtained. If power spectra are degree functions for high energy particles (approximately 10 GeV nucleon/sup -1/), then the spectral exponent ..gamma.. of magnetic field lies between rho and rho-2, where rho is the spectral exponent of cosmic-ray power spectra. The experimental data concerning moderate energy particles are in accordance with ..gamma..=rho, which demonstrates that the magnetic fluctuations are isotropic or cosmic-ray space gradient is small near the Earth orbit.

  17. The distribution of cosmic rays in the galaxy and their dynamics as deduced from recent gamma ray observations. [noting maximum in toroidal region between 4 and 5 kpc from galactic center

    Science.gov (United States)

    Puget, J. L.; Stecker, F. W.

    1974-01-01

    Data from SAS-2 on the galactic gamma ray line flux as a function of longitude is examined. It is shown that the gamma ray emissivity varies with galactocentric distance and is about an order of magnitude higher than the local value in a toroidal region between 4 and 5 kpc from the galactic center. This enhancement is accounted for in part by first-order Fermi acceleration, compression, and trapping of cosmic rays consistent with present ideas of galactic dynamics and galactic structure theory. Calculations indicate that cosmic rays in the 4 to 5 kpc region are trapped and accelerated over a mean time of the order of a few million years or about 2 to 4 times the assumed trapping time in the solar region of the galaxy on the assumption that only an increased cosmic ray flux is responsible for the observed emission. Cosmic ray nucleons, cosmic ray electrons, and ionized hydrogen gas were found to have a strikingly similar distribution in the galaxy according to both the observational data and the theoretical model discussed.

  18. Galactic cosmic ray spectra during solar cycle 23 and 24. Measurement capabilities of the electron proton helium telescope on board SOHO

    Energy Technology Data Exchange (ETDEWEB)

    Kuehl, Patrick; Dresing, Nina; Gieseler, Jan; Heber, Bernd; Klassen, Andreas [Christian-Albrechts Universitaet zu Kiel (Germany)

    2016-07-01

    The solar modulation of galactic cosmic rays (GCR) can be studied in detail by long term variations of the GCR energy spectrum (e.g. on the scales of a solar cycle). With almost 20 years of data, the Electron Proton Helium INstrument (EPHIN) aboard SOHO is well suited for these kind of investigations. Although the design of the instrument is optimized to measure proton and helium isotope spectra up to 50 MeV/nucleon the capability exist that allow to determine energy spectra above 1.5 GeV/nucleon. Therefore we developed a sophisticated inversion method to calculate such proton spectra. The method relies on a GEANT4 Monte Carlo simulation of the instrument and a simplified spacecraft model that calculates the energy response function of EPHIN for electrons, protons and heavier ions. As a result we present galactic cosmic ray spectra from 1995 to 2015. For validation, the derived spectra are compared to AMS, BESS and PAMELA data. Furthermore we discuss the spectra with respect to the solar modulation.

  19. Standard Cosmic Ray Energetics and Light Element Production

    CERN Document Server

    Fields, B D; Cassé, M; Vangioni-Flam, E; Fields, Brian D.; Olive, Keith A.; Casse, Michel; Vangioni-Flam, Elisabeth

    2001-01-01

    The recent observations of Be and B in metal poor stars has led to a reassessment of the origin of the light elements in the early Galaxy. At low it is metallicity ([O/H] < -1.75), it is necessary to introduce a production mechanism which is independent of the interstellar metallicity (primary). At higher metallicities, existing data might indicate that secondary production is dominant. In this paper, we focus on the secondary process, related to the standard Galactic cosmic rays, and we examine the cosmic ray energy requirements for both present and past epochs. We find the power input to maintain the present-day Galactic cosmic ray flux is about 1.5e41 erg/s = 5e50 erg/century. This implies that, if supernovae are the sites of cosmic ray acceleration, the fraction of explosion energy going to accelerated particles is about 30%, a value which we obtain consistently both from considering the present cosmic ray flux and confinement and from the present 9Be and 6Li abundances. Using the abundances of 9Be (an...

  20. THE ORIGIN OF COSMIC RAYS: WHAT CAN GLAST SAY?

    Energy Technology Data Exchange (ETDEWEB)

    Bloom, Elliott

    2000-10-10

    Gamma rays in the band from 30 MeV to 300 GeV, used in combination with direct measurements and with data from radio and X-ray bands, provide a powerful tool for studying the origin of Galactic cosmic rays. Gamma-ray Large Area Space Telescope (GLAST) with its fine 10-20 arcmin angular resolution will be able to map the sites of acceleration of cosmic rays and their interactions with interstellar matter. It will provide information that is necessary to study the acceleration of energetic particles in supernova shocks, their transport in the interstellar medium and penetration into molecular clouds.

  1. On the calibration of a single channel cosmic ray particle detector

    Science.gov (United States)

    Maghrabi, A. H.; Alghamdi, A. S.; Alotaibi, R.; Almutari, M. M.; Garawi, M. S.

    2014-07-01

    Cosmic Ray (CR) variation measurements have been extensively conducted using different type of detectors sensing different components of CR and at different locations around the world. We have constructed and, operated a single channel muon detector in the central part of Saudi Arabia. The main goal of this detector is to record the intensity of cosmic rays on different time scales and investigate their correlations with environment parameters. This detector is expected to fill the gap between neutron monitors and muon telescopes that exist around the world. In this paper, the technical aspects of this detector will be briefly discussed. Calibration procedures conducted to characterize and improve its performance will be detailed. These include the effect of the detector geometry and the internal surface coating.

  2. Silicon telescope for prototype sensor characterisation using particle beam and cosmic rays

    CERN Multimedia

    Fu, Jinlin

    2016-01-01

    We present the design and the performance of a silicon strip telescope that we have built and recently used as reference tracking system for prototype sensor characterisation. The telescope was operated on beam at the CERN SPS and also using cosmic rays in the laboratory. We will describe the data acquisition system, based on a custom electronic board that we have developed, and the online monitoring system to control the quality of the data in real time.

  3. COSMIC-RAY SPALLATION IN RADIO-QUIET ACTIVE GALACTIC NUCLEI: A CASE STUDY OF NGC 4051

    International Nuclear Information System (INIS)

    Turner, T. J.; Miller, L.

    2010-01-01

    We investigate conditions for and consequences of spallation in radio-quiet Seyfert galaxies. The work is motivated by the recent discovery of significant line emission at 5.44 keV in Suzaku data from NGC 4051. The energy of the new line suggests an identification as Cr I Kα emission; however, the line is much stronger than would be expected from material with cosmic abundances, leading to a suggestion of enhancement owing to nuclear spallation of Fe by low-energy cosmic rays from the active nucleus. We find that the highest abundance enhancements are likely to take place in gas out of the plane of the accretion disk and that timescales for spallation could be as short as a few years. The suggestion of a strong nuclear flux of cosmic rays in a radio-quiet active Seyfert galaxy is of particular interest in light of the recent suggestion from Pierre Auger Observatory data that ultra-high-energy cosmic rays may originate in such sources.

  4. Cosmic Rays in Thunderstorms

    Science.gov (United States)

    Buitink, Stijn; Scholten, Olaf; van den Berg, Ad; Ebert, Ute

    2013-04-01

    Cosmic Rays in Thunderstorms Cosmic rays are protons and heavier nuclei that constantly bombard the Earth's atmosphere with energies spanning a vast range from 109 to 1021 eV. At typical altitudes up to 10-20 km they initiate large particle cascades, called extensive air showers, that contain millions to billions of secondary particles depending on their initial energy. These particles include electrons, positrons, hadrons and muons, and are concentrated in a compact particle front that propagates at relativistic speed. In addition, the shower leaves behind a trail of lower energy electrons from ionization of air molecules. Under thunderstorm conditions these electrons contribute to the electrical and ionization processes in the cloud. When the local electric field is strong enough the secondary electrons can create relativistic electron run-away avalanches [1] or even non-relativistic avalanches. Cosmic rays could even trigger lightning inception. Conversely, strong electric fields also influence the development of the air shower [2]. Extensive air showers emit a short (tens of nanoseconds) radio pulse due to deflection of the shower particles in the Earth's magnetic field [3]. Antenna arrays, such as AERA, LOFAR and LOPES detect these pulses in a frequency window of roughly 10-100 MHz. These systems are also sensitive to the radiation from discharges associated to thunderstorms, and provide a means to study the interaction of cosmic ray air showers and the electrical processes in thunderstorms [4]. In this presentation we discuss the involved radiation mechanisms and present analyses of thunderstorm data from air shower arrays [1] A. Gurevich et al., Phys. Lett. A 165, 463 (1992) [2] S. Buitink et al., Astropart. Phys. 33, 1 (2010) [3] H. Falcke et al., Nature 435, 313 (2005) [4] S. Buitink et al., Astron. & Astrophys. 467, 385 (2007)

  5. Annihilation physics of exotic galactic dark matter particles

    Science.gov (United States)

    Stecker, F. W.

    1990-01-01

    Various theoretical arguments make exotic heavy neutral weakly interacting fermions, particularly those predicted by supersymmetry theory, attractive candidates for making up the large amount of unseen gravitating mass in galactic halos. Such particles can annihilate with each other, producing secondary particles of cosmic-ray energies, among which are antiprotons, positrons, neutrinos, and gamma-rays. Spectra and fluxes of these annihilation products can be calculated, partly by making use of positron electron collider data and quantum chromodynamic models of particle production derived therefrom. These spectra may provide detectable signatures of exotic particle remnants of the big bang.

  6. A cosmic-ray nuclear event with an anomalously strong concentration of energy and particles in the central region

    International Nuclear Information System (INIS)

    Amato, N.M.; Arata, N.; Maldonado, R.H.C.

    1987-01-01

    A cosmic-ray-induced nuclear event detected in an emulsion chamber is described. The event consist of 217 shower cores with ΣEγ=1.275 TeV. In a logarithmic scale, energy and particles are emitted most densely at the small lateral distance corresponding to 0.5 mm; 77% of the total energy and 61% of the total multiplicity are inside a radius of 0.65 cm. The shower cores in the central region show exponential-type energy distribution and nonisotropic azimuthal distribution

  7. Constraining heavy dark matter with cosmic-ray antiprotons

    Science.gov (United States)

    Cuoco, Alessandro; Heisig, Jan; Korsmeier, Michael; Krämer, Michael

    2018-04-01

    Cosmic-ray observations provide a powerful probe of dark matter annihilation in the Galaxy. In this paper we derive constraints on heavy dark matter from the recent precise AMS-02 antiproton data. We consider all possible annihilation channels into pairs of standard model particles. Furthermore, we interpret our results in the context of minimal dark matter, including higgsino, wino and quintuplet dark matter. We compare the cosmic-ray antiproton limits to limits from γ-ray observations of dwarf spheroidal galaxies and to limits from γ-ray and γ-line observations towards the Galactic center. While the latter limits are highly dependent on the dark matter density distribution and only exclude a thermal wino for cuspy profiles, the cosmic-ray limits are more robust, strongly disfavoring the thermal wino dark matter scenario even for a conservative estimate of systematic uncertainties.

  8. Relative distribution of cosmic rays and magnetic fields

    Science.gov (United States)

    Seta, Amit; Shukurov, Anvar; Wood, Toby S.; Bushby, Paul J.; Snodin, Andrew P.

    2018-02-01

    Synchrotron radiation from cosmic rays is a key observational probe of the galactic magnetic field. Interpreting synchrotron emission data requires knowledge of the cosmic ray number density, which is often assumed to be in energy equipartition (or otherwise tightly correlated) with the magnetic field energy. However, there is no compelling observational or theoretical reason to expect such a tight correlation to hold across all scales. We use test particle simulations, tracing the propagation of charged particles (protons) through a random magnetic field, to study the cosmic ray distribution at scales comparable to the correlation scale of the turbulent flow in the interstellar medium (≃100 pc in spiral galaxies). In these simulations, we find that there is no spatial correlation between the cosmic ray number density and the magnetic field energy density. In fact, their distributions are approximately statistically independent. We find that low-energy cosmic rays can become trapped between magnetic mirrors, whose location depends more on the structure of the field lines than on the field strength.

  9. The interstellar medium and star formation of galactic disks. I. Interstellar medium and giant molecular cloud properties with diffuse far-ultraviolet and cosmic-ray backgrounds

    Science.gov (United States)

    Li, Qi; Tan, Jonathan C.; Christie, Duncan; Bisbas, Thomas G.; Wu, Benjamin

    2018-01-01

    We present a series of adaptive mesh refinement hydrodynamic simulations of flat rotation curve galactic gas disks, with a detailed treatment of the interstellar medium (ISM) physics of the atomic to molecular phase transition under the influence of diffuse far-ultraviolet (FUV) radiation fields and cosmic-ray backgrounds. We explore the effects of different FUV intensities, including a model with a radial gradient designed to mimic the Milky Way. The effects of cosmic rays, including radial gradients in their heating and ionization rates, are also explored. The final simulations in this series achieve 4 pc resolution across the ˜20 kpc global disk diameter, with heating and cooling followed down to temperatures of ˜10 K. The disks are evolved for 300 Myr, which is enough time for the ISM to achieve a quasi-statistical equilibrium. In particular, the mass fraction of molecular gas is stabilized by ˜200 Myr. Additional global ISM properties are analyzed. Giant molecular clouds (GMCs) are also identified and the statistical properties of their populations are examined. GMCs are tracked as the disks evolve. GMC collisions, which may be a means of triggering star cluster formation, are counted and their rates are compared with analytic models. Relatively frequent GMC collision rates are seen in these simulations, and their implications for understanding GMC properties, including the driving of internal turbulence, are discussed.

  10. Electromagnetic-ram action of the plasma focus as a paradigm for the production of gigantic galactic jets and cosmic rays

    International Nuclear Information System (INIS)

    Bostick, W.

    1985-01-01

    A recent paper suggests that the electromagnetic-ram action of the plasma focus is trying to tell us how cosmic rays acquire their energy. It will be only natural for those theoretical astrophysicists who are steeped in statistical mechanics and turbulent processes, and who are now having a love affair with the black hole, to scoff at such a suggestion. But this author, undaunted, plunges even further into this cosmical question: he has the audacity to suggest further that the gigantic galactic jets in the active galaxies such as are now being observed by the computer-synthesized data of the radio signals at a number of wavelengths with the Very Large Array radio telescope in New Mexico, from radio galaxies like Cygnus A and Centaurus A (NGC 5128), are being produced by an electromagnetic-ram action similar to that of the plasma focus; and further, that this action is producing not only these spectacular jets, but also the acceleration of the cosmic ray at the same time in the same accelerating gap

  11. The interstellar medium and star formation of galactic disks. I. Interstellar medium and giant molecular cloud properties with diffuse far-ultraviolet and cosmic-ray backgrounds

    Science.gov (United States)

    Li, Qi; Tan, Jonathan C.; Christie, Duncan; Bisbas, Thomas G.; Wu, Benjamin

    2018-05-01

    We present a series of adaptive mesh refinement hydrodynamic simulations of flat rotation curve galactic gas disks, with a detailed treatment of the interstellar medium (ISM) physics of the atomic to molecular phase transition under the influence of diffuse far-ultraviolet (FUV) radiation fields and cosmic-ray backgrounds. We explore the effects of different FUV intensities, including a model with a radial gradient designed to mimic the Milky Way. The effects of cosmic rays, including radial gradients in their heating and ionization rates, are also explored. The final simulations in this series achieve 4 pc resolution across the ˜20 kpc global disk diameter, with heating and cooling followed down to temperatures of ˜10 K. The disks are evolved for 300 Myr, which is enough time for the ISM to achieve a quasi-statistical equilibrium. In particular, the mass fraction of molecular gas is stabilized by ˜200 Myr. Additional global ISM properties are analyzed. Giant molecular clouds (GMCs) are also identified and the statistical properties of their populations are examined. GMCs are tracked as the disks evolve. GMC collisions, which may be a means of triggering star cluster formation, are counted and their rates are compared with analytic models. Relatively frequent GMC collision rates are seen in these simulations, and their implications for understanding GMC properties, including the driving of internal turbulence, are discussed.

  12. Atmospheric radiation modeling of galactic cosmic rays using LRO/CRaTER and the EMMREM model with comparisons to balloon and airline based measurements

    Science.gov (United States)

    Joyce, C. J.; Schwadron, N. A.; Townsend, L. W.; deWet, W. C.; Wilson, J. K.; Spence, H. E.; Tobiska, W. K.; Shelton-Mur, K.; Yarborough, A.; Harvey, J.; Herbst, A.; Koske-Phillips, A.; Molina, F.; Omondi, S.; Reid, C.; Reid, D.; Shultz, J.; Stephenson, B.; McDevitt, M.; Phillips, T.

    2016-09-01

    We provide an analysis of the galactic cosmic ray radiation environment of Earth's atmosphere using measurements from the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) aboard the Lunar Reconnaissance Orbiter (LRO) together with the Badhwar-O'Neil model and dose lookup tables generated by the Earth-Moon-Mars Radiation Environment Module (EMMREM). This study demonstrates an updated atmospheric radiation model that uses new dose tables to improve the accuracy of the modeled dose rates. Additionally, a method for computing geomagnetic cutoffs is incorporated into the model in order to account for location-dependent effects of the magnetosphere. Newly available measurements of atmospheric dose rates from instruments aboard commercial aircraft and high-altitude balloons enable us to evaluate the accuracy of the model in computing atmospheric dose rates. When compared to the available observations, the model seems to be reasonably accurate in modeling atmospheric radiation levels, overestimating airline dose rates by an average of 20%, which falls within the uncertainty limit recommended by the International Commission on Radiation Units and Measurements (ICRU). Additionally, measurements made aboard high-altitude balloons during simultaneous launches from New Hampshire and California provide an additional comparison to the model. We also find that the newly incorporated geomagnetic cutoff method enables the model to represent radiation variability as a function of location with sufficient accuracy.

  13. Gardening process of lunar surface layer inferred from the galactic cosmic-ray exposure ages of lunar samples

    International Nuclear Information System (INIS)

    Iriyama, Jun; Honda, Masatake.

    1979-01-01

    From the cosmic-ray exposure age data, (time scale 10 7 - 10 8 years), of the lunar surface materials, we discuss the gardening process of the lunar surface layer caused by the meteoroid impact cratering. At steady state, it is calculated that, in the region within 10 - 50 m of the surface, a mixing rate of 10 -4 to 10 -5 mm/yr is necessary to match the exposure ages. Observed exposure ages of the lunar samples could be explained by the gardening effect calculated using a crater formation rate which is slightly modified from the current crater population data. (author)

  14. Cosmic rays and global warming

    Energy Technology Data Exchange (ETDEWEB)

    Erlykin, A.D. [P.N. Lebedev Physical Institute, Moscow (Russian Federation); Sloan, T. [Lancaster University (United Kingdom); Wolfendale, A.W. [Durham University (United Kingdom)

    2010-07-01

    The possible effects of cosmic rays on clouds could contribute to global warming. The argument is that the observed increased solar activity during the last century caused a decrease in the ionization due to cosmic rays since the lower energy cosmic particles are deflected by the magnetic field created by the increasing solar wind. This would lead to a decrease in cloud cover allowing more heating of the earth by the sun. Meteorological data combined to solar activity observations and simulations show that any effect of solar activity on clouds and the climate is likely to be through irradiance rather than cosmic rays. Since solar irradiance transfers 8 orders of magnitude more energy to the atmosphere than cosmic rays it is more plausible that this can produce a real effect. The total contribution of variable solar activity to global warming is shown to be less than 14% of the total temperature rise. (A.C.)

  15. Cosmic ray physics goes to school

    CERN Multimedia

    2002-01-01

    With the help of a CERN physicist, German Schools bring the Largest Cosmic Ray Detector in Europe one step closer to reality   Eric Berthier and Robert Porret (CERN, ST/HM), Frej Torp and Christian Antfolk from the Polytechnics Arcada in Finland, and Karsten Eggert, physicist at CERN who initiated this project, during the installation of cosmic ray detectors in the Pays de Gex, at point 4. Niina Patrikainen and Frej Torp, Finnish students from Rovaniemi and Arcada Polytechnics, installing cosmic ray counters at the Fachhochschule in Duesseldorf. The science of cosmic ray detection is growing, literally. Cosmic rays, energetic particles from space, strike our planet all the time. They collide with the air molecules in our upper atmosphere and initiate large showers of elementary particles (mainly electrons, photons, hadrons and muons) which rain down upon the earth. The shower size and the particle density in the showers reflect the initial energy of the cosmic ray particle, a detail which makes d...

  16. The anisotropy of cosmic ray particles in the energy range 1011-1019 eV

    International Nuclear Information System (INIS)

    Xu Chunxian

    1985-01-01

    A study of the anisotropy of primary cosmic ray is presented. The expression of the anisotropy is derived in a model of statistical discrete sources in an infinite galaxy. Using these derived formulas, the amplitudes of the first harmonic anisotropies caused by eleven supernovea nearby the Earth are estimated individually and the trend of the resultant anisotropy is investigated. It is found that the expected results can account for the power law of Esup(0.5) of the anisotropy above the energy 5 x 10 15 eV. The Compton-getting effect can cause an additional anisotropy which is independent of energy and added to the resultant anisotropy of these discrete sources. It is apparent that the anisotropies available in the low energy range 10 11 - 10 14 eV are caused by the Compton-Getting effect. Taking the differential spectrum index γ = 2.67 measured in the same energy bound we get the streaming velocity of 35 km/s with respect to the cosmic ray background

  17. Constraints on the galactic distribution of cosmic rays from the COS-B gamma-ray data

    International Nuclear Information System (INIS)

    1985-08-01

    The velocity information of the HI and CO observations is used as a distance indicator to ascertain the spatial distribution of the interstellar gas. Using this distance information, the galacto-centric distribution of the gamma-ray emissivity (the production rate per H atom) is determined for three gamma-ray energy ranges from a correlation study of the gamma-ray intensity maps and the gas-tracer maps for selected galacto-centric distance intervals, taking into account the expected IC contribution and pointlike gamma-ray sources. On the assumption that unresolved gamma-ray point sources do not contribute significantly to the observed gamma-ray emission, the gamma-ray emissivity is proportional to the Cosmic ray density and, more specifically, the energy dependence can be used to study separately the distribution of Cosmic ray electrons and nuclei: whereas the emission for the 300 MeV - 5 GeV range is dominated by π 0 -decay, the 70 MeV - 150 MeV range has a large electron bremsstrahlung contribution

  18. Galactic cosmic ray and El Nino Southern Oscillation trends in International Satellite Cloud Climatology Project D2 low-cloud properties

    DEFF Research Database (Denmark)

    Marsh, N.; Svensmark, Henrik

    2003-01-01

    [1] The recently reported correlation between clouds and galactic cosmic rays (GCR) implies the existence of a previously unknown process linking solar variability and climate. An analysis of the interannual variability of International Satellite Cloud Climatology Project D2 (ISCCP-D2) low-cloud...... a strong correlation with GCR, which suggests that low-cloud properties observed in these regions are less likely to be contaminated from overlying cloud. The GCR-low cloud correlation cannot easily be explained by internal climate processes, changes in direct solar forcing, or UV-ozone interactions...... properties over the period July 1983 to August 1994 suggests that low clouds are statistically related to two processes, (1) GCR and (2) El Nino-Southern Oscillation (ENSO), with GCR explaining a greater percentage of the total variance. Areas where satellites have an unobstructed view of low cloud possess...

  19. Separation of the Galactic Cosmic Rays and Inner Earth Radiation Belt Contributions to the Daily Dose Onboard the International Space Station in 2005-2011

    Science.gov (United States)

    Lishnevskii, A. E.; Benghin, V. V.

    2018-03-01

    The DB-8 detectors of the ISS radiation monitoring system (RMS) have operated almost continuously onboard the ISS service module since August 2001 till December 2014. The RMS data obtained were used for the daily monitoring of the radiation environment aboard the station. This paper considers the technique of RMS data analysis that allows one to distinguish the contributions of galactic cosmic rays and the Earth's inner radiation belt to the daily dose based on the dosimetry data obtained as a result of the station's passage in areas of the highest geomagnetic latitudes. The paper presents the results of an analysis of the dosimetry data based on this technique for 2005-2011, as well as a comparison with similar results the authors obtained previously using the technique based on an analysis of the dosimetry data obtained during station passages in the area of the South Atlantic Anomaly.

  20. Aerosols Produced by Cosmic Rays

    DEFF Research Database (Denmark)

    Enghoff, Martin Andreas Bødker

    an experiment in order to investigate the underlying microphysical processes. The results of this experiment will help to understand whether ionization from cosmic rays, and by implication the related processes in the universe, has a direct influence on Earth’s atmosphere and climate. Since any physical...... mechanism linking cosmic rays to clouds and climate is currently speculative, there have been various suggestions of the role atmospheric ions may play; these involve any one of a number of processes from the nucleation of aerosols up to the collection processes of cloud droplets. We have chosen to start......Satellite observations have shown that the Earth’s cloud cover is strongly correlated with the galactic cosmic ray flux. While this correlation is indicative of a possible physical connection, there is currently no confirmation that a physical mechanism exists. We are therefore setting up...

  1. Production of secondary particles and nuclei in cosmic rays collisions with the interstellar gas using the FLUKA code

    CERN Document Server

    Mazziotta, M N; Ferrari, A; Gaggero, D; Loparco, F; Sala, P R

    2016-01-01

    The measured fluxes of secondary particles produced by the interactions of Cosmic Rays (CRs) with the astronomical environment play a crucial role in understanding the physics of CR transport. In this work we present a comprehensive calculation of the secondary hadron, lepton, gamma-ray and neutrino yields produced by the inelastic interactions between several species of stable or long-lived cosmic rays projectiles (p, D, T, 3He, 4He, 6Li, 7Li, 9Be, 10Be, 10B, 11B, 12C, 13C, 14C, 14N, 15N, 16O, 17O, 18O, 20Ne, 24Mg and 28Si) and different target gas nuclei (p, 4He, 12C, 14N, 16O, 20Ne, 24Mg, 28Si and 40Ar). The yields are calculated using FLUKA, a simulation package designed to compute the energy distributions of secondary products with large accuracy in a wide energy range. The present results provide, for the first time, a complete and self-consistent set of all the relevant inclusive cross sections regarding the whole spectrum of secondary products in nuclear collisions. We cover, for the projectiles, a ki...

  2. Cosmic rays and stochastic magnetic reconnection in the heliotail

    Directory of Open Access Journals (Sweden)

    P. Desiati

    2012-06-01

    Full Text Available Galactic cosmic rays are believed to be generated by diffusive shock acceleration processes in Supernova Remnants, and the arrival direction is likely determined by the distribution of their sources throughout the Galaxy, in particular by the nearest and youngest ones. Transport to Earth through the interstellar medium is expected to affect the cosmic ray properties as well. However, the observed anisotropy of TeV cosmic rays and its energy dependence cannot be explained with diffusion models of particle propagation in the Galaxy. Within a distance of a few parsec, diffusion regime is not valid and particles with energy below about 100 TeV must be influenced by the heliosphere and its elongated tail. The observation of a highly significant localized excess region of cosmic rays from the apparent direction of the downstream interstellar flow at 1–10 TeV energies might provide the first experimental evidence that the heliotail can affect the transport of energetic particles. In particular, TeV cosmic rays propagating through the heliotail interact with the 100–300 AU wide magnetic field polarity domains generated by the 11 yr cycles. Since the strength of non-linear convective processes is expected to be larger than viscous damping, the plasma in the heliotail is turbulent. Where magnetic field domains converge on each other due to solar wind gradient, stochastic magnetic reconnection likely occurs. Such processes may be efficient enough to re-accelerate a fraction of TeV particles as long as scattering processes are not strong. Therefore, the fractional excess of TeV cosmic rays from the narrow region toward the heliotail direction traces sightlines with the lowest smearing scattering effects, that can also explain the observation of a harder than average energy spectrum.

  3. A measurement of the absolute energy spectra of galactic cosmic rays during the 1976-77 solar minimum

    Science.gov (United States)

    Derrickson, J. H.; Parnell, T. A.; Austin, R. W.; Selig, W. J.; Gregory, J. C.

    An instrument designed to measure elemental cosmic ray abundances from boron to nickel in the energy region 0.5-2.0 GeV/nucl was flown on a high altitude balloon from Sioux Falls, South Dakota, on 30 September through 1 October 1976 at an average atmospheric depth of about 5 g/sq cm. Differential energy spectra of B, C, N, O, Ne, Mg, Si and Fe, extrapolated to the top of the atmosphere, were measured. The float altitude exposure of 17 h ended near Alpena, Michigan. The flight trajectory maintained a north easterly heading out of Sioux Falls traversing the upper midwest region between 84 and 97 deg west longitude while remaining between 43.5 and 45 deg north latitude. The maximum vertical cut-off for this flight path was 1.77 GV or 0.35 GeV/nucl.

  4. A measurement of the absolute energy spectra of galactic cosmic rays during the 1976-77 solar minimum

    International Nuclear Information System (INIS)

    Derrickson, J.H.; Parnell, T.A.; Austin, R.W.; Selig, W.J.

    1992-01-01

    An instrument designed to measure elemental cosmic ray abundances from boron to nickel in the energy region 0.5-2.0 GeV nucl -1 was flown on a high altitude balloon from Sioux Falls, South Dakota, on 30 September through 1 October 1976 at an average atmospheric depth of ∼5 g cm -2 . Differential energy spectra of B, C, N, O, Ne, Mg, Si and Fe, extrapolated to the top of the atmosphere, were measured. The float altitude exposure of 17 h ended near Alpena, Michigan. The flight trajectory maintained a north easterly heading out of Sioux Falls traversing the upper mid-west region between 84 o and 97 o west longitude while remaining between 43.5 o and 45 o north latitude. The maximum vertical cut-off for this flight path was 1.77 GV or 0.35 GeV nucl -1 . (author)

  5. Cosmic-ray acceleration at stellar wind terminal shocks

    International Nuclear Information System (INIS)

    Webb, G.M.; Forman, M.A.; Axford, W.I.

    1985-01-01

    Steady-state, spherically symmetric, analytic solutions of the cosmic-ray transport equations, applicable to the problem of acceleration of cosmic rays at the terminal shock to a stellar wind, are studied. The spectra, gradients, and flow patterns of particle modulated and accelerated by the stellar wind and shock are investigated by means of monoenergetic-source solutions at finite radius, as well as solutions with monoenergetic and power-law Galactic spectra. The solutions obtained apply in the test particle limit in which the cosmic rays do not modify the background flow. The solutions show a characteristic power-law momentum spectrum for accelerated particles and a more complex spectrum of particles that are decelerated in the stellar wind. The power-law spectral index depends on the compression ratio of the shock and on the modulation parameters characterizing propagation conditions in the upstream and downstream regions of the shock. Solutions of the transport equations for the total density N (integrated over all energies), pressure P/sub c/, and energy flux F/sub c/ of Galactic cosmic rays interacting with a stellar wind and shock are also studied. The density N(r) increases with radius r, and for strong shocks with large enough modulation parameters, there may be a significant enhancement of the pressure of weakly relativistic particles near the shock compared to the cosmic-ray background pressure P/sub infinity/. The emergent energy flux at infinity is of the order of 4π R 2 V 1 P/sub infinity/ (V 1 is wind velocity upstream of the shock, R is shock radius)

  6. A cosmic-ray nuclear event with an anomalously strong concentration of energy and particles in the central region

    International Nuclear Information System (INIS)

    Amato, N.M.; Arata, N.; Maldonado, R.H.C.

    1986-01-01

    A cosmic-ray induced nuclear event detected in the emulsion chamber is described. The event consists of 217 shower cores with ΣEγ = 1,275 TeV. In log scale, energy and particles are emitted most densely at the small lateral distance corresponding to 0.5 mm; 77 % of the total energy and 61 % of the total multiplicity are inside the radius of 0.65 cm. The shower cores in the central region show exponential-type energy distribution and non-isotropic azimuthal distribution. This event indicates a possibility that phenomena of large transverse momentum could happen to produce a strong concentration of energy and particles in the very forward direction. (Authors) [pt

  7. Propagation of cosmic rays in the Earth's atmosphere

    International Nuclear Information System (INIS)

    Putze, Antje

    2006-06-01

    Cosmic rays are composed of charged particles, which arrive after a long travel through the Galaxy on Earth. Supernova explosions are considered to be galactic sources, which accelerate these particles up to energies around 10 18 eV. Beyond this energy, one supposes that the extragalactic sources, like active galaxy nuclei (AGN), gamma ray bursts or pulsars, are the origin of the ultra high energy cosmic rays. The spectral index of the elemental energy distributions of cosmic rays reflects the dynamic of its propagation, particularly the conjugation of the effects connected to the cosmic ray source spectrum and those connected to its propagation (acceleration, absorption and escape). The evolution of the spectral index with the cosmic-ray particle energy constitutes a sensitive test of the components, which determine this evolution. The precise index measurement of individual elemental spectra of the cosmic rays by AMS up to TeV and by the experiment CREAM beyond it, from TeV to PeV, will permit to proceed in this problematic. One of the difficulties on this measurement is to take well into account the systematic errors. During the data analysis we have to take into account in particular the interaction (diffusion and fragmentation) of the ions while their travel through the Earth's atmosphere. The study of the interaction and the fragmentation of these ions in the atmosphere is hence indispensable and described in this work. The study is based on a matrix calculation, which had been successfully implemented and tested and which has permitted to analyse the effects, caused by the experimental uncertainties on the cross sections, on the spectral index measurement. (author)

  8. ALICE Cosmic Ray Detector

    CERN Multimedia

    Fernandez Tellez, A; Martinez Hernandez, M; Rodriguez Cahuantzi, M

    2013-01-01

    The ALICE underground cavern provides an ideal place for the detection of high energy atmospheric muons coming from cosmic ray showers. ACORDE detects cosmic ray showers by triggering the arrival of muons to the top of the ALICE magnet.

  9. Cosmic Ray Energetics and Mass

    CERN Multimedia

    Baylon cardiel, J L; Wallace, K C; Anderson, T B; Copley, M

    The cosmic-ray energetics and mass (CREAM) investigation is designed to measure cosmic-ray composition to the supernova energy scale of 10$^{15}$ eV in a series of ultra long duration balloon (ULDB) flights. The first flight is planned to be launched from Antarctica in December 2004. The goal is to observe cosmic-ray spectral features and/or abundance changes that might signify a limit to supernova acceleration. The particle ($\\{Z}$) measurements will be made with a timing-based charge detector and a pixelated silicon charge detector to minimize the effect of backscatter from the calorimeter. The particle energy measurements will be made with a transition radiation detector (TRD) for $\\{Z}$ > 3 and a sampling tungsten/scintillator calorimeter for $\\{Z}$ $\\geq$1 particles, allowing inflight cross calibration of the two detectors. The status of the payload construction and flight preparation are reported in this paper.

  10. Biomarker response to galactic cosmic ray-induced NOx and the methane greenhouse effect in the atmosphere of an Earth-like planet orbiting an M dwarf star.

    Science.gov (United States)

    Grenfell, John Lee; Griessmeier, Jean-Mathias; Patzer, Beate; Rauer, Heike; Segura, Antigona; Stadelmann, Anja; Stracke, Barbara; Titz, Ruth; Von Paris, Philip

    2007-02-01

    Planets orbiting in the habitable zone of M dwarf stars are subject to high levels of galactic cosmic rays (GCRs), which produce nitrogen oxides (NOx) in Earth-like atmospheres. We investigate to what extent these NO(Mx) species may modify biomarker compounds such as ozone (O3) and nitrous oxide (N2O), as well as related compounds such as water (H2O) (essential for life) and methane (CH4) (which has both abiotic and biotic sources). Our model results suggest that such signals are robust, changing in the M star world atmospheric column due to GCR NOx effects by up to 20% compared to an M star run without GCR effects, and can therefore survive at least the effects of GCRs. We have not, however, investigated stellar cosmic rays here. CH4 levels are about 10 times higher on M star worlds than on Earth because of a lowering in hydroxyl (OH) in response to changes in the ultraviolet. The higher levels of CH4 are less than reported in previous studies. This difference arose partly because we used different biogenic input. For example, we employed 23% lower CH4 fluxes compared to those studies. Unlike on Earth, relatively modest changes in these fluxes can lead to larger changes in the concentrations of biomarker and related species on the M star world. We calculate a CH4 greenhouse heating effect of up to 4K. O3 photochemistry in terms of the smog mechanism and the catalytic loss cycles on the M star world differs considerably compared with that of Earth.

  11. Cosmic ray electrons and protons, and their antiparticles

    International Nuclear Information System (INIS)

    Boezio, Mirko

    2014-01-01

    Cosmic rays are a sample of solar, galactic, and extragalactic matter. Their origin, acceleration mechanisms, and subsequent propagation toward Earth have intrigued scientists since their discovery. These issues can be studied via analysis of the energy spectra and composition of cosmic rays. Protons are the most abundant component of the cosmic radiation, and many experiments have been dedicated to the accurate measurement of their spectra. Complementary information is provided by electrons, which comprise about 1% of the cosmic radiation. Because of their low mass, electrons experience severe energy losses through synchrotron emission in the galactic magnetic field and inverse Compton scattering of radiation fields. Electrons therefore provide information on the local galactic environment that is not accessible from the study of the cosmic ray nuclei. Antiparticles, namely antiprotons and positrons, are produced in the interaction between cosmic ray nuclei and the interstellar matter. They are therefore intimately linked to the propagation mechanisms of the parent nuclei. Novel sources of primary cosmic ray antiparticles of either astrophysical (e.g., positrons from pulsars) or exotic origin (e.g., annihilation of dark matter particles) may exist. The nature of dark matter is one of the most prominent open questions in science today. An observation of positrons from pulsars would open a new observation window on these sources. Several experiments equipped with state-of-the art detector systems have recently presented results on the energy spectra of electrons, protons, and their antiparticles with a significant improvement in statistics and better control of systematics The status of the field will be reviewed, with a focus on these recent scientific results. (author)

  12. Interaction of clouds with the hot interstellar medium (HIM) and cosmic rays

    International Nuclear Information System (INIS)

    Voelk, H.J.

    1983-01-01

    The modification, by cosmic rays, of the interaction of interstellar clouds with the ambient HIM is considered. Small clouds should still evaporate and thereby exclude cosmic rays if they do so without cosmic rays. The possible mass accretion of massice clouds is reduced by the pressure of the compressed cosmic rays. The consequences for diffuse galactic #betta#-ray emisison are discussed. (orig.)

  13. A measurement of the absolute energy spectra of galactic cosmic rays during the 1976-77 solar minimum

    Energy Technology Data Exchange (ETDEWEB)

    Derrickson, J H; Parnell, T A; Austin, R W; Selig, W J [National Aeronautics and Space Administration, Huntsville, AL (United States). George C. Marshall Space Flight Center; Gregory, J C [Alabama Univ., Huntsville, AL (United States)

    1992-07-01

    An instrument designed to measure elemental cosmic ray abundances from boron to nickel in the energy region 0.5-2.0 GeV nucl[sup -1] was flown on a high altitude balloon from Sioux Falls, South Dakota, on 30 September through 1 October 1976 at an average atmospheric depth of [approx]5 g cm[sup -2]. Differential energy spectra of B, C, N, O, Ne, Mg, Si and Fe, extrapolated to the top of the atmosphere, were measured. The float altitude exposure of 17 h ended near Alpena, Michigan. The flight trajectory maintained a north easterly heading out of Sioux Falls traversing the upper mid-west region between 84[sup o] and 97[sup o] west longitude while remaining between 43.5[sup o] and 45[sup o] north latitude. The maximum vertical cut-off for this flight path was 1.77 GV or 0.35 GeV nucl[sup -1]. (author).

  14. Cosmic ray and gamma astrophysics with the AMS-02 experiment

    International Nuclear Information System (INIS)

    Natale, Sonia

    2006-01-01

    The Alpha Magnetic Spectrometer (AMS) is a particle physics detector designed to operate on the International Space Station (ISS) for a minimum period of three years. The aim of AMS is the direct detection of charged particles in the rigidity range from 0.5 GV to few TV to perform high statistics studies of cosmic rays in space and a search for antimatter and dark matter. AMS will provide precise gamma measurements in the GeV range. In addition, the good angular resolution and identification capabilities of the detector will allow clean studies of galactic and extra-galactic sources, the diffuse gamma background and gamma ray bursts

  15. Experimental data on study of cosmic ray particles in the E≥2 TeV energy range at the Kosmos-1713 satellite with the Sokol-2 device

    International Nuclear Information System (INIS)

    Ivanenko, I.P.; Rapoport, I.D.; Shestoperov, V.Ya.

    1989-01-01

    Primary data of results of experiment on studying the cosmic ray particles with energy in the range exceeding 2 TeV at the Kosmos-1713 satellite using the Sokol-2 equipment are presented in the tabular form. A brief description of the equipment is given. 4 refs.; 2 figs.; 1 tab

  16. Cosmic ray riddle solved?

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    Full text: Physicists from Japan and the United States have discovered a possible answer to the puzzle of the origin of high energy cosmic rays that bombard Earth from all directions in space. Using data from the Japanese/US X-ray astronomical satellite ASCA, physicists have found strong evidence for the production of cosmic particles in the shock wave of a supernova remnant, the expanding fireball produced by the explosion of a star. Primary cosmic rays, mostly electrons and protons, travel near the speed of light. Each second, approximately 4 such particles cross one square centimetre of space just outside the Earth's atmosphere. Subsequently, collisions of these primary particles with atoms in the upper atmosphere produce slower secondary particles. Ever since the discovery of cosmic rays early this century, scientists have debated the origin of these particles and how they can be accelerated to such high speeds. Supernova remnants have long been thought to provide the high energy component, but the evidence has been lacking until now. The international team of investigators used the satellite to determine that cosmic rays are generated profusely in the remains of the supernova of 1006 AD - which appeared to medieval viewers to be as bright as the Moon - and that they are accelerated to high velocities by an iterative process first suggested by Enrico Fermi in 1949. Using solid-state X-ray cameras, the ASCA satellite records simultaneous images and spectra of X-rays from celestial sources, allowing astronomers to distinguish different types of X-ray emission. The tell-tale clue to the discovery was the detection of two diametrically opposite regions in the rapidly expanding supernova remnant, the debris from the stellar explosion. The two regions glow intensely from the synchrotron radiation produced when fast-moving electrons are bent by a magnetic field. The remainder of the supernova remnant, in contrast, emits ordinary ''thermal'' X

  17. FPGA Implementation of an Efficient Algorithm for the Calculation of Charged Particle Trajectories in Cosmic Ray Detectors

    Science.gov (United States)

    Villar, Xabier; Piso, Daniel; Bruguera, Javier D.

    2014-02-01

    This paper presents an FPGA implementation of an algorithm, previously published, for the the reconstruction of cosmic rays' trajectories and the determination of the time of arrival and velocity of the particles. The accuracy and precision issues of the algorithm have been analyzed to propose a suitable implementation. Thus, a 32-bit fixed-point format has been used for the representation of the data values. Moreover, the dependencies among the different operations have been taken into account to obtain a highly parallel and efficient hardware implementation. The final hardware architecture requires 18 cycles to process every particle, and has been exhaustively simulated to validate all the design decisions. The architecture has been mapped over different commercial FPGAs, with a frequency of operation ranging from 300 MHz to 1.3 GHz, depending on the FPGA being used. Consequently, the number of particle trajectories processed per second is between 16 million and 72 million. The high number of particle trajectories calculated per second shows that the proposed FPGA implementation might be used also in high rate environments such as those found in particle and nuclear physics experiments.

  18. Interstellar propagation of low energy cosmic rays

    International Nuclear Information System (INIS)

    Cesarsky, C.J.

    1975-01-01

    Wave particles interactions prevent low energy cosmic rays from propagating at velocities much faster than the Alfven velocity, reducing their range by a factor of order 50. Therefore, supernovae remnants cannot fill the neutral portions of the interstellar medium with 2 MeV cosmic rays [fr

  19. Maximum entropy analysis of cosmic ray composition

    Czech Academy of Sciences Publication Activity Database

    Nosek, D.; Ebr, Jan; Vícha, Jakub; Trávníček, Petr; Nosková, J.

    2016-01-01

    Roč. 76, Mar (2016), s. 9-18 ISSN 0927-6505 R&D Projects: GA ČR(CZ) GA14-17501S Institutional support: RVO:68378271 Keywords : ultra-high energy cosmic rays * extensive air showers * cosmic ray composition Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 3.257, year: 2016

  20. Approximate supernova remnant dynamics with cosmic ray production

    International Nuclear Information System (INIS)

    Voelk, H.J.; Drury, L.O.; Dorfi, E.A.

    1985-01-01

    Supernova explosions are the most violent and energetic events in the galaxy and have long been considered probable sources of cosmic rays. Recent shock acceleration models treating the cosmic rays (CR's) as test particles nb a prescribed supernova remnant (SNR) evolution, indeed indicate an approximate power law momentum distribution f sub source (p) approximation p(-a) for the particles ultimately injected into the interstellar medium (ISM). This spectrum extends almost to the momentum p = 1 million GeV/c, where the break in the observed spectrum occurs. The calculated power law index approximately less than 4.2 agrees with that inferred for the galactic CR sources. The absolute CR intensity can however not be well determined in such a test particle approximation

  1. Approximate supernova remnant dynamics with cosmic ray production

    Science.gov (United States)

    Voelk, H. J.; Drury, L. O.; Dorfi, E. A.

    1985-01-01

    Supernova explosions are the most violent and energetic events in the galaxy and have long been considered probably sources of Cosmic Rays. Recent shock acceleration models treating the Cosmic Rays (CR's) as test particles nb a prescribed Supernova Remnant (SNR) evolution, indeed indicate an approximate power law momentum distribution f sub source (p) approximation p(-a) for the particles ultimately injected into the Interstellar Medium (ISM). This spectrum extends almost to the momentum p = 1 million GeV/c, where the break in the observed spectrum occurs. The calculated power law index approximately less than 4.2 agrees with that inferred for the galactic CR sources. The absolute CR intensity can however not be well determined in such a test particle approximation.

  2. Solar-cosmic-ray variability

    International Nuclear Information System (INIS)

    Reedy, R.C.

    1976-01-01

    The maximum flux of particles from solar events that should be considered in designing the shielding for a space habitation is discussed. The activities of various radionuclides measured in the top few centimeters of lunar rocks are used to examine the variability of solar cosmic ray fluxes over the last five million years. 10 references

  3. High energy physics in cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Lawrence W. [University of Michigan, Ann Arbor, Michigan (United States)

    2013-02-07

    In the first half-century of cosmic ray physics, the primary research focus was on elementary particles; the positron, pi-mesons, mu-mesons, and hyperons were discovered in cosmic rays. Much of this research was carried out at mountain elevations; Pic du Midi in the Pyrenees, Mt. Chacaltaya in Bolivia, and Mt. Evans/Echo Lake in Colorado, among other sites. In the 1960s, claims of the observation of free quarks, and satellite measurements of a significant rise in p-p cross sections, plus the delay in initiating accelerator construction programs for energies above 100 GeV, motivated the Michigan-Wisconsin group to undertake a serious cosmic ray program at Echo Lake. Subsequently, with the succession of higher energy accelerators and colliders at CERN and Fermilab, cosmic ray research has increasingly focused on cosmology and astrophysics, although some groups continue to study cosmic ray particle interactions in emulsion chambers.

  4. Cosmic ray synergies

    CERN Multimedia

    Laëtitia Pedroso

    2010-01-01

    In laboratories, cosmic rays have been the subject of scientific research for many years. A more recent development is their appearance in schools, as educational tools. A recent workshop at CERN, organised by ASPERA in collaboration with EPPOG and EPPCN, had the goal of bringing together ideas and initiatives with a view to setting up a future common project.   Presentation at the workshop on 15 October. In research, as in education, you can sometimes get things done more rapidly and easily by joining forces. For roughly the past decade, physicists have been taking their particle detectors to secondary schools. “The challenge now is to bring all of these existing projects together in a network,” says Arnaud Marsollier, in charge of communication for the ASPERA network and organiser of the workshop. The workshop held on Friday, 15 October was attended by representatives of major European educational projects and members of the European Particle Physics Communication Network...

  5. Anomalous Distributions of Primary Cosmic Rays as Evidence for Time-dependent Particle Acceleration in Supernova Remnants

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yiran; Liu, Siming; Yuan, Qiang, E-mail: liusm@pmo.ac.cn [Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China)

    2017-07-20

    Recent precise measurements of cosmic-ray (CR) spectra show that the energy distribution of protons is softer than those of heavier nuclei, and there are spectral hardenings for all nuclear compositions above ∼200 GV. Models proposed for these anomalies generally assume steady-state solutions of the particle acceleration process. We show that if the diffusion coefficient has a weak dependence on the particle rigidity near shock fronts of supernova remnants (SNRs), time-dependent solutions of the linear diffusive shock acceleration at two stages of SNR evolution can naturally account for these anomalies. The high-energy component of CRs is dominated by acceleration in the free expansion and adiabatic phases with enriched heavy elements and a high shock speed. The low-energy component may be attributed to acceleration by slow shocks propagating in dense molecular clouds with low metallicity in the radiative phase. Instead of a single power-law distribution, the spectra of time-dependent solutions soften gradually with the increase of energy, which may be responsible for the “knee” of CRs.

  6. Study of ultra-energetic cosmic rays at the Pierre Auger Observatory from particle detection to anisotropy measurement

    International Nuclear Information System (INIS)

    Aublin, J.

    2006-09-01

    The Pierre Auger Observatory, still under construction in Argentina, is designed to study the cosmic rays with energies above a few EeV. The experiment combines two complementary techniques: the fluorescence light detection and the sampling of the shower with an array of detectors at ground, covering a surface of 3000 square kilometers. The calculation of the acceptance of the detector, which is of utmost importance to establish the energy spectrum, has been achieved. The method of computation of the acceptance is simple and reliable. The detection efficiency depends on the nature of primary cosmic rays, allowing to study the cosmic rays composition with the surface detector. The calculation of the cosmic rays energy spectrum has been performed, using different methods to estimate the energy of the events. A cross calibration between the fluorescence and the surface detector provides an estimation of the energy almost independent of hadronic interaction models. The study of large scale anisotropies in the cosmic rays angular distribution provides useful informations about the cosmic rays sources and the conditions of propagation. A new analysis method is presented, allowing to estimate the parameters of an underlying dipolar and quadrupolar anisotropy in the data. The method is applied to a preliminary Auger data set. (author)

  7. Simulation of cosmic ray interaction at Saturne

    International Nuclear Information System (INIS)

    Michel, R.

    1996-01-01

    Accelerator experiments provide the basis for the development of physical models describing the production of cosmogenic nuclides by cosmic ray particles. Here, experiments are presented by which the irradiation of stony and iron meteoroids in space by galactic cosmic ray protons was successfully simulated; two thick spherical targets made of gabbro and of steel with radii of 25 and 10 cm, respectively, were isotropically irradiated with 1.6 GeV protons at LNS. The artificial meteoroids contained large numbers of individual small targets of up to 27 elements in which the depth-dependent production of radioactive and stable nuclides was analyzed by model calculations based on depth-dependent spectra of primary and secondary particles calculated by the HERMES code system and on experimental and theoretical thin-target cross sections. Due to the results of the two simulation experiments at LNS a consistent modelling of cosmogenic nuclide production rates in stony and iron meteorites was achieved for the first time which allows to interpret the observed abundances of cosmogenic nuclides in stony and iron meteorites with respect to their exposure histories and to describe the history of the cosmic radiation itself. (author)

  8. Effects of solar activity and galactic cosmic ray cycles on the modulation of the annual average temperature at two sites in southern Brazil

    Science.gov (United States)

    Frigo, Everton; Antonelli, Francesco; da Silva, Djeniffer S. S.; Lima, Pedro C. M.; Pacca, Igor I. G.; Bageston, José V.

    2018-04-01

    Quasi-periodic variations in solar activity and galactic cosmic rays (GCRs) on decadal and bidecadal timescales have been suggested as a climate forcing mechanism for many regions on Earth. One of these regions is southern Brazil, where the lowest values during the last century were observed for the total geomagnetic field intensity at the Earth's surface. These low values are due to the passage of the center of the South Atlantic Magnetic Anomaly (SAMA), which crosses the Brazilian territory from east to west following a latitude of ˜ 26°. In areas with low geomagnetic intensity, such as the SAMA, the incidence of GCRs is increased. Consequently, possible climatic effects related to the GCRs tend to be maximized in this region. In this work, we investigate the relationship between the ˜ 11-year and ˜ 22-year cycles that are related to solar activity and GCRs and the annual average temperature recorded between 1936 and 2014 at two weather stations, both located near a latitude of 26° S but at different longitudes. The first of these stations (Torres - TOR) is located in the coastal region, and the other (Iraí - IRA) is located in the interior, around 450 km from the Atlantic Ocean. Sunspot data and the solar modulation potential for cosmic rays were used as proxies for the solar activity and the GCRs, respectively. Our investigation of the influence of decadal and bidecadal cycles in temperature data was carried out using the wavelet transform coherence (WTC) spectrum. The results indicate that periodicities of 11 years may have continuously modulated the climate at TOR via a nonlinear mechanism, while at IRA, the effects of this 11-year modulation period were intermittent. Four temperature maxima, separated by around 20 years, were detected in the same years at both weather stations. These temperature maxima are almost coincident with the maxima of the odd solar cycles. Furthermore, these maxima occur after transitions from even to odd solar cycles, that is

  9. High-energy cosmic rays

    CERN Document Server

    Cronin, James Watson

    1996-01-01

    Recently two cosmic rays with energy in excess of 2 1020 eV have been recorded. These are some 108 times more energetic than the protons produced by accelerators on earth. There is no credible understanding of the mechanism of acceleration by known a Because of the short mean free path in the cosmic background radiation they must come from nearby distances on a cosmological scale (< 50 Mpc). Their magnetic rigidity suggests that they should point to their source. Lectures will cover the present available data on the highest energy cosmic rays, their detection, possible acceleration mechanisms, their propagation in the galaxy and in extra galactic space and design of new detectors where simulations of air show ers play an important role.

  10. Synthesis of ideas on cosmic ray origin and propagation

    International Nuclear Information System (INIS)

    Wolfendale, A.W.

    1986-01-01

    An attempt is made, based largely on ideas reported at this Advanced Studies Institute, to synthesise ideas which have been put forward on cosmic ray origin and propagation. The conclusions drawn are as follows. The bulk of cosmic rays detected at earth appear to be of Galactic origin, many probably having come from supernova remnants, at least at the lowest energies. Only above 10/sup 19/ eV does an extragalactic origin appear likely and here the VIRGO cluster at the centre of our Supercluster is a likely source. Although extragalactic cosmic rays are not present to a large extent their energy density could well be significant and the case is made for its being about 10/sup -4/ eV cm/sup -3/. Concerning the controversy about continuous or ''quick'' particle acceleration, it appears necessary to separate origin and acceleration. The interesting model put forward by Schlickeiser involving what might be called pseudo-continuous acceleration appears to require that the bulk of the particle acceleration occurs in a very large Galactic halo, the secondaries being produced only in the gas disk. Problems are likely, however, with the expected fluxes of X-rays and radio synchrotron radiation

  11. Observation of Galactic and Solar Cosmic Rays from October 13, 1959 to February 17, 1961 with Explorer VII (Satellite 1959 Iota)

    Science.gov (United States)

    Lin, Wei Ching

    1961-01-01

    This paper gives a comprehensive summary of cosmic-ray intensity observations at high latitudes over North America and over Australia in the altitude range 550 to 1100 km by means of Geiger tubes in Explorer VII (Earth satellite 1959 Iota). The time period covered is October 13, 1959 to February 17, 1961. Of special interest are the observational data on some 20 solar cosmic-ray events including major events of early April 1960, early September 1960, and of mid-November 1960. Detailed study of the latitude dependence of solar cosmic ray intensity will be presented in a later companion paper.

  12. Sequential measurements of spectrum and dose for cosmic-ray neutrons on the ground

    International Nuclear Information System (INIS)

    Hirabayashi, N.; Nunomiya, T.; Suzuki, H.; Nakamura, T.

    2002-01-01

    The earth is continually bathed in high-energy particles that come from outside the solar system, known as galactic cosmic rays. When these particles penetrate the magnetic fields of the solar system and the Earth and reach the Earth's atmosphere, they collide with atomic nuclei in air and secondary cosmic rays of every kind. On the other hand, levels of accumulation of the semiconductor increase recently, and the soft error that the cosmic-ray neutrons cause has been regarded as questionable. There have been long-term measurements of cosmic-ray neutron fluence at several places in the world, but no systematic study on cosmic-ray neutron spectrum measurements. This study aimed to measure the cosmic-ray neutron spectrum and dose on the ground during the solar maximum period of 2000 to 2002. Measurements have been continuing in a cabin of Tohoku University Kawauchi campus, by using five multi-moderator spectrometers (Bonner sphere), 12.7 cm diam by 12.7 cm long NE213 scintillator, and rem counter. The Bonner sphere uses a 5.08 cm diam spherical 3 He gas proportional counter and the rem counter uses a 12.7 cm diam 3 He gas counter. The neutron spectra were obtained by unfolding from the count rates measured with the Bonner sphere using the SAND code and the pulse height spectra measured with the NE213 scintillator using the FORIST code . The cosmic- ray neutron spectrum and ambient dose rates have been measured sequentially from April 2001. Furthermore, the correlation between ambient dose rate and the atmospheric pressure was investigated with a barometer. We are also very much interested in the variation of neutron spectrum following big solar flares. From the sequential measurements, we found that the cosmic-ray neutron spectrum has two peaks at around 1 MeV and at around 100 MeV, and the higher energy peak increases with a big solar flare

  13. Cosmic Ray Antimatter

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    Over the last decade, space-born experiments have delivered new measurements of high energy cosmic-ray (CR) antiprotons and positrons, opening new frontiers in energy reach and precision. While being a promising discovery tool for new physics or exotic astrophysical phenomena, an irreducible background of antimatter comes from CR collisions with interstellar matter in the Galaxy. Understanding this irreducible source or constraining it from first principles is an interesting challenge: a game of hide-and-seek where the objective is to identify the laws of basic particle physics among the forest of astrophysical uncertainties. I describe an attempt to obtain such understanding, combining information from a zoo of CR species including massive nuclei and relativistic radioisotopes. I show that: (i) CR antiprotons most likely come from CR-gas collisions; (ii) positron data is consistent with, and suggestive of the same astrophysical production mechanism responsible for antiprotons and dominated by proton-proton c...

  14. Department of Cosmic Ray Physics: Overview

    International Nuclear Information System (INIS)

    Szabelski, J.

    2001-01-01

    Full text: The Department of Cosmic Ray Physics in Lodz is involved in basic research in the area of high-energy physics and cosmic ray physics related to: Experimental and phenomenological studies of Extensive Air Showers induced by cosmic ray particles. Studies of ultra-high energy (above 10 19 eV) cosmic rays: determination of energy and primary particle mass composition. Studies of asymptotic properties of hadronic interactions based on the analysis of cosmic ray propagation through the atmosphere. Studies of mass composition of cosmic rays in the energy range 10 15 -10 17 eV. Registration of cosmic ray intensity variation correlated with solar activity. Theoretical and experimental studies of Extensive Air Shower properties are performed mostly based on the results obtained by the Lodz Extensive Air Shower Array. We have noticed unexplainable delayed signals registered about 500-900 microseconds after the main EAS pulse. We prepared hardware for further experimental study of this effect. In September we have started registration of 5 GeV muon flux with the underground muon telescope. We registered 3 decreases of muon intensity correlated with Forbush decreases registered at lower energies. Variations of primary cosmic ray of energies up to about 100 GeV were responsible for our registrations. These set the upper limits for geometrical size of geomagnetic disturbances in interplanetary space. In construction and data interpretation of cosmic ray experiments, the Lodz group collaborates with many foreign institutes and laboratories: Forschungszentrum in Karlsruhe (Germany), College de France, Institute for Nuclear Studies of the Russian Academy of Sciences and Uppsala University (Sweden). We have organised (together with the Physics Department of the University of Lodz) the 17 th European Cosmic Ray Symposium (24-?8 July 2000) in which about 150 physicists participated (about 100 from abroad). (author)

  15. Closing CMS to hunt cosmic rays

    CERN Multimedia

    Claudia Marcelloni

    2006-01-01

    Every second the Earth is bombarded by billions of cosmic rays and occasionally one of these cosmic particles will collide with the Earth's atmosphere generating a shower of particles known as an 'air shower'. This is similiar to the collisions and subsequent particle showers observed in accelerators such as the LHC. Here the CMS detector is closed so that systems can be tested using muon cosmic rays in the 'Cosmic Challenge'.

  16. Particle physics explanations for ultra-high energy cosmic ray events

    Indian Academy of Sciences (India)

    this talk I briefly summarize several proposed particle physics explanations: a breakdown ... as primaries, and magnetic monopoles with mass below 1010 GeV as primaries. .... these monopoles would be the ultimate test of this explanation.

  17. A simple method to extract information on anisotropy of particle fluxes from spin-modulated counting rates of cosmic ray telescopes

    International Nuclear Information System (INIS)

    Hsieh, K.C.; Lin, Y.C.; Sullivan, J.D.

    1975-01-01

    A simple method to extract information on anisotropy of particle fluxes from data collected by cosmic ray telescopes on spinning spacecraft but without sectored accumulators is presented. Application of this method to specific satellite data demonstrates that it requires no prior assumption on the form of angular distribution of the fluxes; furthermore, self-consistency ensures the validity of the results thus obtained. The examples show perfect agreement with the corresponding magnetic field directions

  18. Proceedings of the 21. European Cosmic Ray Symposium

    International Nuclear Information System (INIS)

    Kiraly, P.; Kudela, K.; Wolfendale, A. W.

    2008-09-01

    Scientific symposium deals with problems of cosmic ray. The Symposium included the following sessions: (1): Relationship of cosmic rays to the environment; (2) Energetic particles and the magnetosphere of the Earth; (3) Energetic particles in the heliosphere; (4) Solar-terrestrial effects on different time scales; (5) Cosmic rays below the knee; (6) Cosmic rays above the knee (7) High energy interactions; (8) GeV and TeV gamma ray astronomy; (9) European projects related to cosmic rays; Future perspectives. Proceedings contains 122 papers dealing with the scope of INIS.

  19. Search for positron anisotropies in cosmic rays with AMS

    Energy Technology Data Exchange (ETDEWEB)

    Machate, Fabian [1. Physikalisches Institut B, RWTH Aachen University (Germany)

    2016-07-01

    The Alpha Magnetic Spectrometer (AMS-02) on the International Space Station has observed a significant excess of cosmic ray positrons over the background expected from secondary production at energies above 10 GeV. Nearby pulsars and annihilating dark matter particles as a primary source of electrons and positrons have been discussed as an explanation. A possible way of distinguishing between pulsar and dark matter origin is the measurement of dipole anisotropies in the positron flux or the positron to electron ratio. Any anisotropy will be reduced by diffusion in galactic magnetic fields to below the percent level. AMS-02 is the leading space-based experiment for cosmic ray detection and well suited for this search. A new analysis procedure for anisotropies using an event sample with large acceptance is presented. It relies on the ability of the Transition Radiation Detector (TRD) to separate positrons from the proton background.

  20. A neural network device for on-line particle identification in cosmic ray experiments

    International Nuclear Information System (INIS)

    Scrimaglio, R.; Finetti, N.; D'Altorio, L.; Rantucci, E.; Raso, M.; Segreto, E.; Tassoni, A.; Cardarilli, G.C.

    2004-01-01

    On-line particle identification is one of the main goals of many experiments in space both for rare event studies and for optimizing measurements along the orbital trajectory. Neural networks can be a useful tool for signal processing and real time data analysis in such experiments. In this document we report on the performances of a programmable neural device which was developed in VLSI analog/digital technology. Neurons and synapses were accomplished by making use of Operational Transconductance Amplifier (OTA) structures. In this paper we report on the results of measurements performed in order to verify the agreement of the characteristic curves of each elementary cell with simulations and on the device performances obtained by implementing simple neural structures on the VLSI chip. A feed-forward neural network (Multi-Layer Perceptron, MLP) was implemented on the VLSI chip and trained to identify particles by processing the signals of two-dimensional position-sensitive Si detectors. The radiation monitoring device consisted of three double-sided silicon strip detectors. From the analysis of a set of simulated data it was found that the MLP implemented on the neural device gave results comparable with those obtained with the standard method of analysis confirming that the implemented neural network could be employed for real time particle identification

  1. The long-term variability of cosmic ray protons in the heliosphere: A modeling approach

    Directory of Open Access Journals (Sweden)

    M.S. Potgieter

    2013-05-01

    Full Text Available Galactic cosmic rays are charged particles created in our galaxy and beyond. They propagate through interstellar space to eventually reach the heliosphere and Earth. Their transport in the heliosphere is subjected to four modulation processes: diffusion, convection, adiabatic energy changes and particle drifts. Time-dependent changes, caused by solar activity which varies from minimum to maximum every ∼11 years, are reflected in cosmic ray observations at and near Earth and along spacecraft trajectories. Using a time-dependent compound numerical model, the time variation of cosmic ray protons in the heliosphere is studied. It is shown that the modeling approach is successful and can be used to study long-term modulation cycles.

  2. Cosmic-ray-produced stable nuclides: various production rates and their implications

    International Nuclear Information System (INIS)

    Reedy, R.C.

    1981-01-01

    The rates for a number of reactions producing certain stable nuclides, such as 3 He and 4 He, and fission in the moon are calculated for galactic-cosmic-ray particles and for solar protons. Solar-proton-induced reactions with bromine usually are not an important source of cosmogenic Kr isotopes. The 130 Ba(n,p) reaction cannot account for the undercalculation of 130 Xe production rates. Calculated production rates of 15 N, 13 C, and 2 H agree fairly well with rates inferred from measured excesses of these isotopes in samples with long exposure ages. Cosmic-ray-induced fission of U and Th can produce significant amounts of fission tracks and of 86 Kr, 134 Xe, and 136 Xe, especially in samples with long exposures to cosmic-ray particles

  3. Influence of the terrestrial magnetic field geometry on the cutoff rigidity of cosmic ray particles

    International Nuclear Information System (INIS)

    Herbst, K.; Kopp, A.; Heber, B.

    2013-01-01

    Studies of the propagation of charged energetic particles in the Earth's magnetic field go back to Carl Stoermer. In the end, his investigations finally lead to the definition of the so-called cutoff rigidity RC; that is, the minimum momentum per charge a particle must have in order to reach a certain geographical location. Employing Monte Carlo simulations with the PLANETOCOSMICS code we investigate the correlation between the geomagnetic field structure and the cutoff rigidity. We show that the geometry of the magnetic field has a considerable influence on the resulting cutoff rigidity distribution. Furthermore, we will present a simple geometry-based parameter, δB, which is able to reflect the location-dependent cutoff rigidity. We show that this correlation is also visible in the temporal evolution of the Earth's magnetic field, at least over the last 100 yr. Using latitude scans with neutron monitors, changes of the relative counting rates at different positions are calculated, showing small variations for, e.g., Kiel and Moscow, while large ones occur at Mexico City as well as on the British Virgin Islands.

  4. Cosmic Rays in Intermittent Magnetic Fields

    International Nuclear Information System (INIS)

    Shukurov, Anvar; Seta, Amit; Bushby, Paul J.; Wood, Toby S.; Snodin, Andrew P.

    2017-01-01

    The propagation of cosmic rays in turbulent magnetic fields is a diffusive process driven by the scattering of the charged particles by random magnetic fluctuations. Such fields are usually highly intermittent, consisting of intense magnetic filaments and ribbons surrounded by weaker, unstructured fluctuations. Studies of cosmic-ray propagation have largely overlooked intermittency, instead adopting Gaussian random magnetic fields. Using test particle simulations, we calculate cosmic-ray diffusivity in intermittent, dynamo-generated magnetic fields. The results are compared with those obtained from non-intermittent magnetic fields having identical power spectra. The presence of magnetic intermittency significantly enhances cosmic-ray diffusion over a wide range of particle energies. We demonstrate that the results can be interpreted in terms of a correlated random walk.

  5. Cosmic Rays in Intermittent Magnetic Fields

    Energy Technology Data Exchange (ETDEWEB)

    Shukurov, Anvar; Seta, Amit; Bushby, Paul J.; Wood, Toby S. [School of Mathematics and Statistics, Newcastle University, Newcastle Upon Tyne NE1 7RU (United Kingdom); Snodin, Andrew P., E-mail: a.seta1@ncl.ac.uk, E-mail: amitseta90@gmail.com [Department of Mathematics, Faculty of Applied Science, King Mongkut’s University of Technology North Bangkok, Bangkok 10800 (Thailand)

    2017-04-10

    The propagation of cosmic rays in turbulent magnetic fields is a diffusive process driven by the scattering of the charged particles by random magnetic fluctuations. Such fields are usually highly intermittent, consisting of intense magnetic filaments and ribbons surrounded by weaker, unstructured fluctuations. Studies of cosmic-ray propagation have largely overlooked intermittency, instead adopting Gaussian random magnetic fields. Using test particle simulations, we calculate cosmic-ray diffusivity in intermittent, dynamo-generated magnetic fields. The results are compared with those obtained from non-intermittent magnetic fields having identical power spectra. The presence of magnetic intermittency significantly enhances cosmic-ray diffusion over a wide range of particle energies. We demonstrate that the results can be interpreted in terms of a correlated random walk.

  6. Propagation of ultrahigh-energy cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Stanev, Todor [Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States)], E-mail: stanev@bartol.udel.edu

    2009-06-15

    We briefly describe the energy loss processes of ultrahigh-energy protons, heavier nuclei and {gamma}-rays in interactions with the universal photon fields of the Universe. We then discuss the modification of the accelerated cosmic-ray energy spectrum in propagation by the energy loss processes and the charged cosmic-ray scattering in the extragalactic magnetic fields. The energy lost by the ultrahigh-energy cosmic rays goes into {gamma}-rays and neutrinos that carry additional information about the sources of highest energy particles. The new experimental results of the HiRes and the Auger collaborations are discussed in view of the predictions from propagation calculations.

  7. 1020eV cosmic ray and particle physics with IceCube

    International Nuclear Information System (INIS)

    Alvarez-Muniz, J.; Halzen, F.

    2001-01-01

    We show that a kilometer-scale neutrino observatory, though optimized for detecting neutrinos of TeV to PeV energy, can reveal the science associated with the enigmatic super-EeV radiation in the Universe. Speculations regarding its origin include heavy relics from the early Universe, particle interactions associated with the Greisen cutoff, and topological defects which are remnant cosmic structures associated with phase transitions in grand unified gauge theories. We show that it is a misconception that new instruments optimized to EeV energy can exclusively do this important science. Because kilometer-scale neutrino telescopes such as IceCube can reject the atmospheric neutrino background by identifying the very high energy of the signal events, they have sensitivity over the full solid angle, including the horizon where most of the signal is concentrated. This is critical because upgoing neutrino-induced muons, considered in previous calculations, are absorbed by the Earth. Previous calculations have underestimated the event rates of IceCube for EeV signals by over one order of magnitude

  8. Cosmic-ray interactions and dating of meteorite stranding surfaces with cosmogenic nuclides

    Energy Technology Data Exchange (ETDEWEB)

    Reedy, R.C.

    1988-01-01

    A wide variety of products from cosmic-ray interactions have been measured in terrestrial or extraterrestrial samples. These ''cosmogenic'' products include radiation damage tracks and rare nuclides that are made by nuclear reactions. They often have been used to determine the fluxes and composition of cosmic-ray particles in the past, but they are usually used to study the history of the ''target'' (such as the time period that it was exposed to cosmic-ray particles). Products made by both the high-energy galactic cosmic rays and energetic particles emitted irregularly from the Sun have been extensively studied. Some of these cosmogenic products, especially nuclides, have been or can be applied to studies of Antarctic meteorite stranding surfaces, the ice surfaces in Antarctica where meteorites have been found. Cosmogenic nuclides studied in samples from Antarctica and reported by others elsewhere in this volume include those in meteorites, especially radionuclides used to determine terrestrial ages, and those made in situ in terrestrial rocks. Cosmogenic nuclides made in the Earth's atmosphere or brought in with cosmic dust have also been studied in polar ice, and it should also be possible to measure nuclides made in situ in ice. As an introduction to cosmogenic nuclides and their applications, cosmic rays and their interactions will be presented below and production systematics of cosmogenic nuclides in these various media will be discussed later. 20 refs., 2 tabs.

  9. Cosmic-ray interactions and dating of meteorite stranding surfaces with cosmogenic nuclides

    International Nuclear Information System (INIS)

    Reedy, R.C.

    1988-01-01

    A wide variety of products from cosmic-ray interactions have been measured in terrestrial or extraterrestrial samples. These ''cosmogenic'' products include radiation damage tracks and rare nuclides that are made by nuclear reactions. They often have been used to determine the fluxes and composition of cosmic-ray particles in the past, but they are usually used to study the history of the ''target'' (such as the time period that it was exposed to cosmic-ray particles). Products made by both the high-energy galactic cosmic rays and energetic particles emitted irregularly from the Sun have been extensively studied. Some of these cosmogenic products, especially nuclides, have been or can be applied to studies of Antarctic meteorite stranding surfaces, the ice surfaces in Antarctica where meteorites have been found. Cosmogenic nuclides studied in samples from Antarctica and reported by others elsewhere in this volume include those in meteorites, especially radionuclides used to determine terrestrial ages, and those made in situ in terrestrial rocks. Cosmogenic nuclides made in the Earth's atmosphere or brought in with cosmic dust have also been studied in polar ice, and it should also be possible to measure nuclides made in situ in ice. As an introduction to cosmogenic nuclides and their applications, cosmic rays and their interactions will be presented below and production systematics of cosmogenic nuclides in these various media will be discussed later. 20 refs., 2 tabs

  10. Multi-spectra Cosmic Ray Flux Measurement

    Science.gov (United States)

    He, Xiaochun; Dayananda, Mathes

    2010-02-01

    The Earth's upper atmosphere is constantly bombarded by rain of charged particles known as primary cosmic rays. These primary cosmic rays will collide with the atmospheric molecules and create extensive secondary particles which shower downward to the surface of the Earth. In recent years, a few studies have been done regarding to the applications of the cosmic ray measurements and the correlations between the Earth's climate conditions and the cosmic ray fluxes [1,2,3]. Most of the particles, which reach to the surface of the Earth, are muons together with a small percentage of electrons, gammas, neutrons, etc. At Georgia State University, multiple cosmic ray particle detectors have been constructed to measure the fluxes and energy distributions of the secondary cosmic ray particles. In this presentation, we will briefly describe these prototype detectors and show the preliminary test results. Reference: [1] K.Borozdin, G.Hogan, C.Morris, W.Priedhorsky, A.Saunders, L.Shultz, M.Teasdale, Nature, Vol.422, 277 (2003). [2] L.V. Egorova, V. Ya Vovk, O.A. Troshichev, Journal of Atmospheric and Terrestrial Physics 62, 955-966 (2000). [3] Henrik Svensmark, Phy. Rev. Lett. 81, 5027 (1998). )

  11. Cosmic ray acceleration mechanisms

    International Nuclear Information System (INIS)

    Cesarsky, C.J.

    1982-09-01

    We present a brief summary of some of the most popular theories of cosmic ray acceleration: Fermi acceleration, its application to acceleration by shocks in a scattering medium, and impulsive acceleration by relativistic shocks

  12. 11. European cosmic ray symposium

    International Nuclear Information System (INIS)

    1989-03-01

    The biannual Symposium includes all aspects of cosmic ray research. The scientific programme was organized under three main headings: Cosmic rays in the heliosphere, Cosmic rays in the interstellar and extragalactic space, Properties of high-energy interactions as studied by cosmic rays. Seven invited talks were indexed seprately for the INIS database. (R.P.)

  13. CREME96: A revision of the Cosmic Ray Effects on Micro-Electronics code

    International Nuclear Information System (INIS)

    Tylka, A.J.; Adams, J.H. Jr.; Boberg, P.R.

    1997-01-01

    CREME96 is an update of the Cosmic Ray Effects on Micro-Electronics code, a widely-used suite of programs for creating numerical models of the ionizing-radiation environment in near-Earth orbits and for evaluating radiation effects in spacecraft. CREME96, which is now available over the World-Wide Web (WWW) at http://crsp3.nrl.navy.mil/creme96/, has many significant features, including (1) improved models of the galactic cosmic ray, anomalous cosmic ray, and solar energetic particle (flare) components of the near-Earth environment; (2) improved geomagnetic transmission calculations; (3) improved nuclear transport routines; (4) improved single-event upset (SEU) calculation techniques, for both proton-induced and direct-ionization-induced SEUs; and (5) an easy-to-use graphical interface, with extensive on-line tutorial information. In this paper the authors document some of these improvements

  14. On the Energy Spectra of GeV/TeV Cosmic Ray Leptons

    Energy Technology Data Exchange (ETDEWEB)

    Stawarz, Lukasz; /KIPAC, Menlo Park /Jagiellonian U., Astron. Observ.; Petrosian, Vahe; /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., Appl. Phys. Dept.; Blandford, Roger D.; /KIPAC, Menlo Park

    2011-08-19

    Recent observations of cosmic ray electrons from several instruments have revealed various degrees of deviation in the measured electron energy distribution from a simple power-law, in a form of an excess around 0.1 to 1 TeV energies. An even more prominent deviation and excess has been observed in the fraction of cosmic ray positrons around 10 and 100 GeV energies. These observations have received considerable attention and many theoretical models have been proposed to explain them. The models rely on either dark matter annihilation/decay or specific nearby astrophysical sources, and involve several additional assumptions regarding the dark matter distribution or particle acceleration. In this paper we show that the observed excesses in the electron spectrum may be easily reproduced without invoking any unusual sources other than the general diffuse Galactic components of cosmic rays. The model presented here assumes a power-law injection of electrons (and protons) by supernova remnants, and evaluates their expected energy spectrum based on a simple kinetic equation describing the propagation of charged particles in the interstellar medium. The primary physical effect involved is the Klein-Nishina suppression of the electron cooling rate around TeV energies. With a very reasonable choice of the model parameters characterizing the local interstellar medium, we can reproduce the most recent observations by Fermi and HESS experiments. Interestingly, in our model the injection spectral index of cosmic ray electrons becomes comparable to, or even equal to that of cosmic ray protons. The Klein-Nishina effect may also affect the propagation of the secondary e{sup {+-}} pairs, and therefore modify the cosmic ray positron-to-electron ratio. We have explored this possibility by considering two mechanisms for production of e{sup {+-}} pairs within the Galaxy. The first is due to the decay of {pi}{sup {+-}}'s produced by interaction of cosmic ray nuclei with ambient

  15. Relativistic transport theory for cosmic-rays

    International Nuclear Information System (INIS)

    Webb, G.M.

    1985-01-01

    Various aspects of the transport of cosmic-rays in a relativistically moving magnetized plasma supporting a spectrum of hydromagnetic waves that scatter the cosmic-rays are presented. A local Lorentz frame moving with the waves or turbulence scattering the cosmic-rays is used to specify the individual particle momentum. The comoving frame is in general a noninertial frame in which the observer's volume element is expanding and shearing, geometric energy change terms appear in the cosmic-ray transport equation which consist of the relativistic generalization of the adiabatic deceleration term and a further term involving the acceleration vector of the scatterers. A relativistic version of the pitch angle evolution equation, including the effects of adiabatic focussing, pitch angle scattering, and energy changes is presented

  16. The ALTA cosmic ray experiment electronics system

    International Nuclear Information System (INIS)

    Brouwer, W.; Burris, W.J.; Caron, B.; Hewlett, J.; Holm, L.; Hamilton, A.; McDonald, W.J.; Pinfold, J.L.; Price, P.; Schaapman, J.R.; Sibley, L.; Soluk, R.A.; Wampler, L.J.

    2005-01-01

    Understanding the origin and propagation of high-energy cosmic rays is a fundamental area of astroparticle physics with major unanswered questions. The study of cosmic rays with energy more than 10 14 eV, probed only by ground-based experiments, has been restricted by the low particle flux. The Alberta Large-area Time-coincidence Array (ALTA) uses a sparse array of cosmic ray detection stations located in high schools across a large geographical area to search for non-random high-energy cosmic ray phenomena. Custom-built ALTA electronics is based on a modular board design. Its function is to control the detectors at each ALTA site allowing precise measurements of event timing and energy in the local detectors as well as time synchronization of all of the sites in the array using the global positioning system

  17. Cosmic-ray-modified stellar winds. III. A numerical iterative approach

    International Nuclear Information System (INIS)

    Ko, C.M.; Jokipii, J.R.; Webb, G.M.

    1988-01-01

    A numerical iterative method is used to determine the modification of a stellar wind flow with a termination shock by the galactic cosmic rays. A two-fluid model consisting of cosmic rays and thermal stellar wind gas is used in which the cosmic rays are coupled to the background flow via scattering with magnetohydrodynamic waves or irregularities. A polytropic model is used to describe the thermal stellar wind gas, and the cosmic-rays are modeled as a hot, low-density gas with negligible mass flux. The positive galactic cosmic-ray pressure gradient serves to brake the outflowing stellar wind gas, and the cosmic rays modify the location of the critical point of the wind, the location of the shock, the wind fluid velocity profile, and the thermal gas entropy constants on both sides of the shock. The transfer of energy to the cosmic rays results in an outward radial flux of cosmic-ray energy. 21 references

  18. Signatures of cosmic-ray interactions on the solar surface

    Science.gov (United States)

    Seckel, D.; Stanev, Todor; Gaisser, T. K.

    1991-01-01

    The fluxes of neutrinos, gamma rays, antiprotons, neutrons, and antineutrons that result from collisions of high-energy Galactic cosmic rays with the solar atmosphere are estimated. The results are sensitive to assumptions about cosmic-ray transport in the magnetic fields of the inner solar system. The high-energy photon flux should be observable by the Gamma Ray Observatory. The neutrino flux should produce less than one event per year in the next generation of neutrino telescopes. The antiproton flux is unobservable against the Galactic background. The neutron and antineutron fluxes are detectable only if neutrons produced in terrestrial cosmic-ray events may be discriminated against.

  19. Elemental composition of cosmic ray

    International Nuclear Information System (INIS)

    Yanagida, Shohei

    1987-01-01

    The report first summarizes some data that have been obtained so far from observation of isotopes and elements in cosmic rays in the low energy region. Then, objectives of studies planned to be carried out with Astromag are outlined and the number of incident particles expected to be measured by baloon observation is estimated. Heavy elements with atomic numbers of greater than 30 are considered to be formed through neutron absorption reactions by the s- or r-process. Observations show that products of the r-process is abundant in cosmic ray sources. The escape length depends on energy. In relation to this, it has been reported that the ratios Ar-Fe and Ca-Fe increase above 200 GeV-n while such a tendency is not observed for K, Sc, Ti or V. Thus, no satisfactory models are available at present which can fully explain the changes in the escape length. The ratio 3 He- 4 He in the range of 5 - 10 GeV-n is inconsistent with the general theory that interprets the escape length of heavy elements. Some models, including the supermetallicity model and Wolf Rayet theory, have been proposed to explain unusual ratios of isotopes in cosmic rays, but more measurements are required to verify them. It is expected that Astromag can serve to make observations that can clarify these points. (Nogami, K.)

  20. Cosmic ray modulation

    International Nuclear Information System (INIS)

    Ueno, Hirosachi

    1974-01-01

    It is important to know the physical state of solar plasma region by the observation of intensity variation of cosmic ray which passed through the solar plasma region, because earth magnetosphere is formed by the interaction between geomagnetic field and solar plasma flow. The observation of cosmic ray intensity is useful to know the average condition of the space of 0.1--3 A.U., and gives the structure of the magnetic field in solar wind affecting the earth magnetosphere. The observation of neutron component in cosmic ray has been carried out at Norikura, Tokyo, Fukushima and Morioka. The lower limit of the energy of incident cosmic ray which can be observed at each station is different, and the fine structure of the variation can be known by comparison. The intensity of meson component in cosmic ray has been measured in underground, and the state of solar plasma region 2--3 A.U. from the earth can be known. The underground measurement has been made at Takeyama and Matsumoto, and a new station at Sakashita is proposed. The measurement at Sakashita will be made by proportional counters at the depth of 100m (water equivalent). Arrangement of detectors is shown. (Kato, T.)

  1. Cosmic Rays and Climate

    CERN Document Server

    Kirkby, Jasper

    2007-01-01

    Among the most puzzling questions in climate change is that of solar-climate variability, which has attracted the attention of scientists for more than two centuries. Until recently, even the existence of solar-climate variability has been controversial—perhaps because the observations had largely involved correlations between climate and the sunspot cycle that had persisted for only a few decades. Over the last few years, however, diverse reconstructions of past climate change have revealed clear associations with cosmic ray variations recorded in cosmogenic isotope archives, providing persuasive evidence for solar or cosmic ray forcing of the climate. However, despite the increasing evidence of its importance, solar-climate variability is likely to remain controversial until a physical mechanism is established. Although this remains a mystery, observations suggest that cloud cover may be influenced by cosmic rays, which are modulated by the solar wind and, on longer time scales, by the geomagnetic fiel...

  2. HERSCHEL SURVEY OF GALACTIC OH{sup +}, H{sub 2}O{sup +}, AND H{sub 3}O{sup +}: PROBING THE MOLECULAR HYDROGEN FRACTION AND COSMIC-RAY IONIZATION RATE

    Energy Technology Data Exchange (ETDEWEB)

    Indriolo, Nick; Neufeld, D. A. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Gerin, M.; Falgarone, E. [LERMA, Observatoire de Paris, Ecole Normale Supérieure, PSL Research University, CNRS, UMR8112, F-75014 Paris (France); Schilke, P.; Chambers, E. T.; Ossenkopf, V. [I. Physikalisches Institut der Universität zu Köln, Zülpicher Str. 77, 50937 Köln (Germany); Benz, A. O. [Institute of Astronomy, ETH Zürich (Switzerland); Winkel, B.; Menten, K. M. [MPI für Radioastronomie, Bonn (Germany); Black, John H.; Persson, C. M. [Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, SE-43992 Onsala (Sweden); Bruderer, S.; Van Dishoeck, E. F. [Max Planck Institut für Extraterrestrische Physik, Garching (Germany); Godard, B.; Lis, D. C. [Sorbonne Universités, UPMC Univ. Paris 06, UMR8112, LERMA, F-75005 Paris (France); Goicoechea, J. R. [Instituto de Ciencias de Materiales de Madrid (CSIC), E-28049 Cantoblanco, Madrid (Spain); Gupta, H. [California Institute of Technology, Pasadena, CA 91125 (United States); Sonnentrucker, P. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Van der Tak, F. F. S. [SRON Netherlands Institute for Space Research, Landleven 12, 9747 AD Groningen (Netherlands); and others

    2015-02-10

    In diffuse interstellar clouds the chemistry that leads to the formation of the oxygen-bearing ions OH{sup +}, H{sub 2}O{sup +}, and H{sub 3}O{sup +} begins with the ionization of atomic hydrogen by cosmic rays, and continues through subsequent hydrogen abstraction reactions involving H{sub 2}. Given these reaction pathways, the observed abundances of these molecules are useful in constraining both the total cosmic-ray ionization rate of atomic hydrogen (ζ{sub H}) and molecular hydrogen fraction (f{sub H{sub 2}}). We present observations targeting transitions of OH{sup +}, H{sub 2}O{sup +}, and H{sub 3}O{sup +} made with the Herschel Space Observatory along 20 Galactic sight lines toward bright submillimeter continuum sources. Both OH{sup +} and H{sub 2}O{sup +} are detected in absorption in multiple velocity components along every sight line, but H{sub 3}O{sup +} is only detected along 7 sight lines. From the molecular abundances we compute f{sub H{sub 2}} in multiple distinct components along each line of sight, and find a Gaussian distribution with mean and standard deviation 0.042 ± 0.018. This confirms previous findings that OH{sup +} and H{sub 2}O{sup +} primarily reside in gas with low H{sub 2} fractions. We also infer ζ{sub H} throughout our sample, and find a lognormal distribution with mean log (ζ{sub H}) = –15.75 (ζ{sub H} = 1.78 × 10{sup –16} s{sup –1}) and standard deviation 0.29 for gas within the Galactic disk, but outside of the Galactic center. This is in good agreement with the mean and distribution of cosmic-ray ionization rates previously inferred from H{sub 3}{sup +} observations. Ionization rates in the Galactic center tend to be 10-100 times larger than found in the Galactic disk, also in accord with prior studies.

  3. Educational Cosmic Ray Arrays

    International Nuclear Information System (INIS)

    Soluk, R. A.

    2006-01-01

    In the last decade a great deal of interest has arisen in using sparse arrays of cosmic ray detectors located at schools as a means of doing both outreach and physics research. This approach has the unique advantage of involving grade school students in an actual ongoing experiment, rather then a simple teaching exercise, while at the same time providing researchers with the basic infrastructure for installation of cosmic ray detectors. A survey is made of projects in North America and Europe and in particular the ALTA experiment at the University of Alberta which was the first experiment operating under this paradigm

  4. Department of Cosmic Ray Physics - Overview

    International Nuclear Information System (INIS)

    Szabelski, J.

    2010-01-01

    Full text: The 31 st International Cosmic Ray Conference (31.ICRC) was held in Lodz on 7-15 July 2009. The Conference was organized by the University of Lodz (Department of High Energy Astrophysics and Department of Astrophysics) and IPJ (Department of Cosmic Ray Physics). ICRCs are held every two years and are the largest forums to present and discuss the current status of Cosmic Ray studies. The Conference we co-organized gathered about 750 scientists (including about 50 from Poland). This was a remarkable event. The Department of Cosmic Ray Physics in Lodz is involved in basic research in the field of high energy Cosmic Rays. Cosmic Rays are energetic panicles from outside the Solar System. Most studies of Cosmic Rays address fundamental problems: - the nature of the physical and astrophysical processes responsible for the high energies of the particles. - experimental search for sources of Cosmic Rays, - studies of the astrophysical conditions at the acceleration sites, - properties of particle interactions at very high energies. Presentation of Cosmic Ray registration to high school students has become a popular way to introduce panicle physics detectors and elementary particle detection techniques to young people, in Lodz and Poznan we organize workshops on particle physics for high school students. This is part of the European activity: EPPOG Masterclass - Hands on CERN. Energetic Cosmic Ray particles produce cascades of panicles in the atmosphere, called Extensive Air Showers (EAS). Registering EASs and their properties is the main means of studying experimentally high energy Cosmic Rays: · The satellite experiment JEM-EUSO will observe EASs from the International Space Station. The main target is to find Cosmic Ray Sources for the highest energy Cosmic Rays. JEM-EUSO will collect a large number of events since it will observe a large area of the atmosphere. We are participating in the preparation of this mission. · The KASCADE-Grande addresses

  5. Cosmic rays and the search for a Lorentz Invariance Violation

    International Nuclear Information System (INIS)

    Bietenholz, Wolfgang

    2008-11-01

    This is an introductory review about the on-going search for a signal of Lorentz Invariance Violation (LIV) in cosmic rays. We first summarise basic aspects of cosmic rays, focusing on rays of ultra high energy (UHECRs). We discuss the Greisen-Zatsepin-Kuz'min (GZK) energy cutoff for cosmic protons, which is predicted due to photopion production in the Cosmic Microwave Background (CMB). This is a process of modest energy in the proton rest frame. It can be investigated to a high precision in the laboratory, if Lorentz transformations apply even at factors γ ∝ O(10 11 ). For heavier nuclei the energy attenuation is even faster due to photo-disintegration, again if this process is Lorentz invariant. Hence the viability of Lorentz symmetry up to tremendous γ-factors - far beyond accelerator tests - is a central issue. Next we comment on conceptual aspects of Lorentz Invariance and the possibility of its spontaneous breaking. This could lead to slightly particle dependent ''Maximal Attainable Velocities''. We discuss their effect in decays, Cerenkov radiation, the GZK cutoff and neutrino oscillation in cosmic rays. We also review the search for LIV in cosmic γ-rays. For multi TeV γ-rays we possibly encounter another puzzle related to the transparency of the CMB, similar to the GZK cutoff, due to electron/positron creation and subsequent inverse Compton scattering. The photons emitted in a Gamma Ray Burst occur at lower energies, but their very long path provides access to information not far from the Planck scale. We discuss conceivable non-linear photon dispersions based on non-commutative geometry or effective approaches. No LIV has been observed so far. However, even extremely tiny LIV effects could change the predictions for cosmic ray physics drastically. An Appendix is devoted to the recent hypothesis by the Pierre Auger Collaboration, which identifies nearby Active Galactic Nuclei - or objects next to them - as probable UHECR sources. (orig.)

  6. Propagation of cosmic rays in the Earth's atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Putze, Antje [LPSC-CNRS-IN2P3, 53, avenue des Martyrs, 38021 Grenoble cedex (France)

    2006-06-15

    Cosmic rays are composed of charged particles, which arrive after a long travel through the Galaxy on Earth. Supernova explosions are considered to be galactic sources, which accelerate these particles up to energies around 10{sup 18} eV. Beyond this energy, one supposes that the extragalactic sources, like active galaxy nuclei (AGN), gamma ray bursts or pulsars, are the origin of the ultra high energy cosmic rays. The spectral index of the elemental energy distributions of cosmic rays reflects the dynamic of its propagation, particularly the conjugation of the effects connected to the cosmic ray source spectrum and those connected to its propagation (acceleration, absorption and escape). The evolution of the spectral index with the cosmic-ray particle energy constitutes a sensitive test of the components, which determine this evolution. The precise index measurement of individual elemental spectra of the cosmic rays by AMS up to TeV and by the experiment CREAM beyond it, from TeV to PeV, will permit to proceed in this problematic. One of the difficulties on this measurement is to take well into account the systematic errors. During the data analysis we have to take into account in particular the interaction (diffusion and fragmentation) of the ions while their travel through the Earth's atmosphere. The study of the interaction and the fragmentation of these ions in the atmosphere is hence indispensable and described in this work. The study is based on a matrix calculation, which had been successfully implemented and tested and which has permitted to analyse the effects, caused by the experimental uncertainties on the cross sections, on the spectral index measurement. (author)

  7. Catching Cosmic Rays with a DSLR

    Science.gov (United States)

    Sibbernsen, Kendra

    2010-01-01

    Cosmic rays are high-energy particles from outer space that continually strike the Earth's atmosphere and produce cascades of secondary particles, which reach the surface of the Earth, mainly in the form of muons. These particles can be detected with scintillator detectors, Geiger counters, cloud chambers, and also can be recorded with commonly…

  8. Cosmic rays and tests of fundamental principles

    International Nuclear Information System (INIS)

    Gonzalez-Mestres, Luis

    2011-01-01

    It is now widely acknowledged that cosmic rays experiments can test possible new physics directly generated at the Planck scale or at some other fundamental scale. By studying particle properties at energies far beyond the reach of any man-made accelerator, they can yield unique checks of basic principles. A well-known example is provided by possible tests of special relativity at the highest cosmic-ray energies. But other essential ingredients of standard theories can in principle be tested: quantum mechanics, uncertainty principle, energy and momentum conservation, effective space-time dimensions, hamiltonian and lagrangian formalisms, postulates of cosmology, vacuum dynamics and particle propagation, quark and gluon confinement, elementariness of particles... Standard particle physics or string-like patterns may have a composite origin able to manifest itself through specific cosmic-ray signatures. Ultra-high energy cosmic rays, but also cosmic rays at lower energies, are probes of both 'conventional' and new Physics. Status, prospects, new ideas, and open questions in the field are discussed.

  9. Department of Cosmic Ray Physics; Overview

    International Nuclear Information System (INIS)

    Szabelski, J.

    2003-01-01

    Full text: Department of Cosmic Ray Physics in Lodz is involved in basic research in the area of high-energy physics and cosmic ray physics related to: - Experimental and phenomenological studies of Extensive Air Showers induced by cosmic ray particles. - Studies of ultra-high energy (above 10 19 eV) cosmic rays: determination of energy spectrum and mass composition of primary particles - Studies of asymptotic properties of hadronic interactions based on the analysis of cosmic ray propagation through the atmosphere. - Studies of mass composition of cosmic rays in the energy range 10 15 - 10 17 eV. - Registration of cosmic ray intensity variation correlated with solar activity. Theoretical and experimental studies of Extensive Air Shower properties are performed mostly basing on the results obtained by the Lodz Extensive Air Shower Array. We have noticed unexplainable delayed signals registered about 500-900 microseconds after the main EAS pulse. Neutron transport simulations were performed in collaboration with JINR in Dubna. We prepared hardware for further experimental study of this effect. Continuous registrations of 5 GeV muon flux with the underground muon telescope have been carried on over the year 2001. We have detected several changes of muon intensity correlated with Forbush decreases registered at lower energies. We have also started registrations of muon counting rate in the on-surface scintillation detectors. These measurements will be included to the analysis of the disturbed energy spectrum of primary cosmic rays and its dependence on interplanetary disturbances related to the solar activity. In construction and data interpretation of cosmic ray experiments the Lodz group collaborates with many foreign institutes and laboratories: Forschungszentrum in Karlsruhe (Germany), College de France, Institute for Nuclear Studies of the Russian Academy of Sciences, JINR in Dubna (Russia), Uppsala University (Sweden) and DESY (Germany). We have prepared a

  10. Department of Cosmic Ray Physics: Overview

    International Nuclear Information System (INIS)

    Szabelski, J.

    2002-01-01

    Full text:The Department of Cosmic Ray Physics in Lodz is involved in basic research in the area of high-energy physics and cosmic ray physics related to: * Experimental and phenomenological studies of Extensive Air Showers induced by cosmic ray particles. * Studies of ultra-high energy (above 10 19 eV) cosmic rays: determination of energy spectrum and mass composition of primary particles * Studies of asymptotic properties of hadronic interactions based on the analysis of cosmic ray propagation through the atmosphere. * Studies of mass composition of cosmic rays in the energy range 10 15 -10 17 eV. * Registration of cosmic ray intensity variation correlated with solar activity. Theoretical and experimental studies of Extensive Air Shower properties are performed mostly based on the results obtained by the Lodz Extensive Air Shower Array. We have noticed unexplainable delayed signals registered about 500-900 microseconds after the main EAS pulse. We prepared hardware for further experimental study of this effect. Continuous registrations of 5 GeV muon flux with the underground muon telescope have been carried on during 2001. We detected several changes of muon intensity correlated with Forbush decreases registered at lower energies. We have also started registration of the muon counting rate in on-surface scintillation detectors. These measurements will be included to the analysis of the disturbed energy spectrum of primary cosmic rays and its dependence on interplanetary disturbances related to solar activity. In construction and data interpretation of cosmic ray experiments the Lodz group collaborates with many foreign institutes and laboratories: Forschungszentrum in Karlsruhe (Germany), College de France, Institute for Nuclear Studies of the Russian Academy of Sciences, Uppsala University (Sweden) and DESY (Germany). We have prepared a project of large air shower array for studies of cosmic rays up to 10 20 eV. Detectors would be placed on the roofs of high

  11. Lunar radionuclide records of average solar-cosmic-ray fluxes over the last ten million years

    International Nuclear Information System (INIS)

    Reedy, R.C.

    1980-01-01

    Because changes in solar activity can modify the fluxes of cosmic-ray particles in the solar system, the nature of the galactic and solar cosmic rays and their interactions with matter are described and used to study the ancient sun. The use of cosmogenic nuclides in meteorites and lunar samples as detectors of past cosmic-ray variations are discussed. Meteorite records of the history of the galactic cosmic rays are reviewed. The fluxes of solar protons over various time periods as determined from lunar radionuclide data are presented and examined. The intensities of solar protons emitted during 1954 to 1964 (11-year solar cycle number 19) were much larger than those for 1965 to 1975 (solar cycle 20). Average solar-proton fluxes determined for the last one to ten million years from lunar 26 Al and 53 Mn data show little variation and are similar to the fluxes for recent solar cycles. Lunar activities of 14 C (and preliminary results for 81 Kr) indicate that the average fluxes of solar protons over the last 10 4 (and 10 5 ) years are several times larger than those for the last 10 6 to 10 7 years; however, cross-section measurements and other work are needed to confirm these flux variations

  12. A two-zone cosmic ray propagation model and its implication of the surviving fraction of radioactive cosmic ray isotopes

    International Nuclear Information System (INIS)

    Simon, M.; Scherzer, R.; Enge, W.

    1977-01-01

    In cosmic ray propagation calculations one can usually assume a homogeneous distribution of interstellar matter. The crucial astrophysical parameters in these models are: The path length distribution, the age of the cosmic ray particles and the interstellar matter density. These values are interrelated. The surviving fraction of radioactive cosmic ray isotopes is often used to determine a mean matter density of that region, where the cosmic ray particles may mainly reside. Using a Monte Carlo Propagation Program we calculated the change in the surviving fraction quantitatively assuming a region around the sources with higher matter density. (author)

  13. Cosmic rays on earth

    International Nuclear Information System (INIS)

    Allkofer, O.C.; Grieder, P.K.F.

    1984-01-01

    A data collection is presented that covers cosmic rays on earth. Included are all relevant data on flux and intensity measurements, energy spectra, and related data of all primary and secondary components of the cosmic radiation at all levels in the atmosphere, at sea level and underground. In those cases where no useful experimental data have been available, theoretical predictions were substituted. (GSCH)

  14. Cosmic rays and climate

    CERN Multimedia

    2009-01-01

    Inside the new chamber the CLOUD team will be able to recreate the conditions of any part of the atmosphere, from the polar stratosphere to the low level tropics (top). The new chamber safely in position in the East hall. Once carefully cleaned the chamber will be turned sideways onto its legs ready for the beam of 'cosmic rays' (bottom).

  15. Some problems of physics of ultrahigh energy cosmic rays

    International Nuclear Information System (INIS)

    Isaev, P.S.

    1999-01-01

    Nearest 15-20 years will be years of flourishing of experimental researches into the energy of cosmic rays at > or ∼ 10 15 eV and of new discoveries in the physics of elementary particles of ultrahigh energies. Unsolved problems of modern physics of ultrahigh energy cosmic rays, which are relevant to the problems of elementary particles physics, are reviewed

  16. The Cosmic Ray Tracking (CRT) detector system

    International Nuclear Information System (INIS)

    Bernloehr, K.; Gamp, S.; Hermann, G.; Hofmann, W.; Kihm, T.; Knoeppler, J.; Leffers, G.; Matheis, V.; Panter, M.; Trunk, U.; Ulrich, M.; Wolf, T.; Zink, R.; Heintze, J.

    1996-01-01

    The Cosmic Ray Tracking (CRT) project represents a study on the use of tracking detectors of the time projection chamber type to detect secondary cosmic ray particles in extensive air showers. In reconstructing the arrival direction of the primary cosmic ray particles, the CRT detectors take advantage of the angular correlation of secondary particles with the cosmic rays leading to these air showers. In this paper, the detector hardware including the custom-designed electronics system is described in detail. A CRT detector module provides an active area of 2.5 m 2 and allows to measure track directions with a precision of 0.4 circle . It consists of two circular drift chambers of 1.8 m diameter with six sense wires each, and a 10 cm thick iron plate between the two chambers. Each detector has a local electronics box with a readout, trigger, and monitoring system. The detectors can distinguish penetrating muons from other types of charged secondaries. A large detector array could be used to search for γ-ray point sources at energies above several TeV and for studies of the cosmic-ray composition. Ten detectors are in operation at the site of the HEGRA air shower array. (orig.)

  17. Cosmic rays and tests of fundamental principles

    Science.gov (United States)

    Gonzalez-Mestres, Luis

    2011-03-01

    It is now widely acknowledged that cosmic rays experiments can test possible new physics directly generated at the Planck scale or at some other fundamental scale. By studying particle properties at energies far beyond the reach of any man-made accelerator, they can yield unique checks of basic principles. A well-known example is provided by possible tests of special relativity at the highest cosmic-ray energies. But other essential ingredients of standard theories can in principle be tested: quantum mechanics, uncertainty principle, energy and momentum conservation, effective space-time dimensions, hamiltonian and lagrangian formalisms, postulates of cosmology, vacuum dynamics and particle propagation, quark and gluon confinement, elementariness of particles…Standard particle physics or string-like patterns may have a composite origin able to manifest itself through specific cosmic-ray signatures. Ultra-high energy cosmic rays, but also cosmic rays at lower energies, are probes of both "conventional" and new Physics. Status, prospects, new ideas, and open questions in the field are discussed.

  18. The basis for cosmic ray feedback: Written on the wind

    Science.gov (United States)

    Zweibel, Ellen G.

    2017-05-01

    Star formation and supermassive black hole growth in galaxies appear to be self-limiting. The mechanisms for self-regulation are known as feedback. Cosmic rays, the relativistic particle component of interstellar and intergalactic plasma, are among the agents of feedback. Because cosmic rays are virtually collisionless in the plasma environments of interest, their interaction with the ambient medium is primarily mediated by large scale magnetic fields and kinetic scale plasma waves. Because kinetic scales are much smaller than global scales, this interaction is most conveniently described by fluid models. In this paper, I discuss the kinetic theory and the classical theory of cosmic ray hydrodynamics (CCRH) which follows from assuming cosmic rays interact only with self-excited waves. I generalize CCRH to generalized cosmic ray hydrodynamics, which accommodates interactions with extrinsic turbulence, present examples of cosmic ray feedback, and assess where progress is needed.

  19. Department of Cosmic Ray Physics; Overview

    International Nuclear Information System (INIS)

    Szabelski, J.

    2004-01-01

    Full text: Cosmic Rays are energetic particles from outside the Solar System. The energy spectrum (power law energy dependence) suggests a non-thermal origin of these particles. Most of the studies of Cosmic Rays address fundamental problems such as: - the nature of the physical and astrophysical processes responsible for the high energies of particles (up to about 10 20 eV/particle), - estimation of the astrophysical conditions at the acceleration sites and/or a search for sources of Cosmic Rays, - properties of high energy particle interactions at very high energies (nuclear interactions at energies exceeding energies available in the laboratories). Some Cosmic Ray studies might have practical (commercial) implications, e.g. - ''cosmic weather'' forecast - predictions of geomagnetic disturbances related to Solar activity changes (due to large Solar Flares / events of Coronal Mass Ejections); these are important for large electricity networks, gas pipes, radio-wave connections, space missions and satellite experiments. The Department of Cosmic Ray Physics in Lodz is involved in basic research in the high energy Cosmic Ray field. Energetic Cosmic Ray particles produce cascades of particles in the atmosphere, called Extensive Air Showers (EAS). Registering EAS and their properties is the main theme of experimental studies of very high energy Cosmic Rays. In the Lodz Department we run an Extensive Air Shower array where EAS are registered. We concentrate our experimental research on the explanation of particle detection delayed by hundreds of microseconds with respect to the main EAS signals. In the underground (I5 meters) laboratory we continuously register muon (5 GeV energy threshold) flux with the multidirectional telescope. We have observed several disturbances (Forbush Decreases) in muon counting rates. The interpretation of these events for ''cosmic weather'' and for Cosmic Ray transport models in the interplanetary plasma are on going in collaboration with

  20. Radio detection of cosmic rays with LOFAR

    NARCIS (Netherlands)

    Hörandel, J. R.; Buitink, S.; Corstanje, A.; Enriquez, J. E.; Falcke, H.; Karskens, T.; Krause, M.; Nelles, A.; Rachen, J. P.; Rossetto, L.; Schellart, P.; Scholten, O.; Ter Veen, S.; Thoudam, S.; Trinh, T. N G

    2015-01-01

    When high-energy cosmic rays (ionized atomic nuclei) impinge on the atmosphere of the Earth they interact with atomic nuclei and initiate cascades of secondary particles - the extensive air showers. Many of the secondary particles in the air showers are electrons and positrons. They cause radiation

  1. Cosmic rays and climate

    CERN Multimedia

    CERN. Geneva

    2009-01-01

    The current understanding of climate change in the industrial age is that it is predominantly caused by anthropogenic greenhouse gases, with relatively small natural contributions due to solar irradiance and volcanoes. However, palaeoclimatic reconstructions show that the climate has frequently varied on 100-year time scales during the Holocene (last 10 kyr) by amounts comparable to the present warming - and yet the mechanism or mechanisms are not understood. Some of these reconstructions show clear associations with solar variability, which is recorded in the light radio-isotope archives that measure past variations of cosmic ray intensity. However, despite the increasing evidence of its importance, solar-climate variability is likely to remain controversial until a physical mechanism is established. Estimated changes of solar irradiance on these time scales appear to be too small to account for the climate observations. This raises the question of whether cosmic rays may directly affect the climate, provi...

  2. COSMIC-RAY POSITRONS FROM MILLISECOND PULSARS

    Energy Technology Data Exchange (ETDEWEB)

    Venter, C.; Kopp, A.; Büsching, I. [Centre for Space Research, North-West University, Potchefstroom Campus, Private Bag X6001, Potchefstroom 2520 (South Africa); Harding, A. K. [Astrophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Gonthier, P. L. [Hope College, Department of Physics, Holland, MI (United States)

    2015-07-10

    Observations by the Fermi Large Area Telescope of γ-ray millisecond pulsar (MSP) light curves imply copious pair production in their magnetospheres, and not exclusively in those of younger pulsars. Such pair cascades may be a primary source of Galactic electrons and positrons, contributing to the observed enhancement in positron flux above ∼10 GeV. Fermi has also uncovered many new MSPs, impacting Galactic stellar population models. We investigate the contribution of Galactic MSPs to the flux of terrestrial cosmic-ray electrons and positrons. Our population synthesis code predicts the source properties of present-day MSPs. We simulate their pair spectra invoking an offset-dipole magnetic field. We also consider positrons and electrons that have been further accelerated to energies of several TeV by strong intrabinary shocks in black widow (BW) and redback (RB) systems. Since MSPs are not surrounded by pulsar wind nebulae or supernova shells, we assume that the pairs freely escape and undergo losses only in the intergalactic medium. We compute the transported pair spectra at Earth, following their diffusion and energy loss through the Galaxy. The predicted particle flux increases for non-zero offsets of the magnetic polar caps. Pair cascades from the magnetospheres of MSPs are only modest contributors around a few tens of GeV to the lepton fluxes measured by the Alpha Magnetic Spectrometer, PAMELA, and Fermi, after which this component cuts off. The contribution by BWs and RBs may, however, reach levels of a few tens of percent at tens of TeV, depending on model parameters.

  3. Cosmic ray propagation with CRPropa 3

    International Nuclear Information System (INIS)

    Batista, R Alves; Evoli, C; Sigl, G; Van Vliet, A; Erdmann, M; Kuempel, D; Mueller, G; Walz, D; Kampert, K-H; Winchen, T

    2015-01-01

    Solving the question of the origin of ultra-high energy cosmic rays (UHECRs) requires the development of detailed simulation tools in order to interpret the experimental data and draw conclusions on the UHECR universe. CRPropa is a public Monte Carlo code for the galactic and extragalactic propagation of cosmic ray nuclei above ∼ 10 17 eV, as well as their photon and neutrino secondaries. In this contribution the new algorithms and features of CRPropa 3, the next major release, are presented. CRPropa 3 introduces time-dependent scenarios to include cosmic evolution in the presence of cosmic ray deflections in magnetic fields. The usage of high resolution magnetic fields is facilitated by shared memory parallelism, modulated fields and fields with heterogeneous resolution. Galactic propagation is enabled through the implementation of galactic magnetic field models, as well as an efficient forward propagation technique through transformation matrices. To make use of the large Python ecosystem in astrophysics CRPropa 3 can be steered and extended in Python. (paper)

  4. Cosmic ray modulation

    Science.gov (United States)

    Agarwal Mishra, Rekha; Mishra, Rajesh Kumar

    2016-07-01

    Propagation of cosmic rays to and inside the heliosphere, encounter an outward moving solar wind with cyclic magnetic field fluctuation and turbulence, causing convection and diffusion in the heliosphere. Cosmic ray counts from the ground ground-based neutron monitors at different cut of rigidity show intensity changes, which are anti-correlated with sunspot numbers. They also lose energy as they propagate towards the Earth and experience various types of modulations due to different solar activity indices. In this work, we study the first three harmonics of cosmic ray intensity on geo-magnetically quiet days over the period 1965-2014 for Beijing, Moscow and Tokyo neutron monitoring stations located at different cut off rigidity. The amplitude of first harmonic remains high for low cutoff rigidity as compared to high cutoff rigidity on quiet days. The diurnal amplitude significantly decreases during solar activity minimum years. The diurnal time of maximum significantly shifts to an earlier time as compared to the corotational direction having different cutoff rigidities. The time of maximum for first harmonic significantly shifts towards later hours and for second harmonic it shifts towards earlier hours at low cutoff rigidity station as compared to the high cut off rigidity station on quiet days. The amplitude of second/third harmonics shows a good positive correlation with solar wind velocity, while the others (i.e. amplitude and phase) have no significant correlation on quiet days. The amplitude and direction of the anisotropy on quiet days does not show any significant dependence on high-speed solar wind streams for these neutron monitoring stations of different cutoff rigidity threshold. Keywords: cosmic ray, cut off rigidity, quiet days, harmonics, amplitude, phase.

  5. Department of Cosmic Ray Physics - Overview

    International Nuclear Information System (INIS)

    Szabelski, J.

    2007-01-01

    The Department of Cosmic Ray Physics in Lodz is involved in basic research in the high energy Cosmic Ray field. Cosmic Rays are energetic particles from outside the Solar System. The energy spectrum (power law energy dependence) suggests non-thermal origin of these particles. Most of the studies of Cosmic Rays address fundamental problems: · the nature of the physical and astrophysical processes responsible for high energies of particles (up to about 1020 eV/particle), · an estimation of the astrophysical conditions at the acceleration sites and/or search for sources of Cosmic Rays, · properties of high energy particle interactions at very high energies (nuclear interactions at energies exceeding energy available in the laboratories). Some Cosmic Ray studies might have practical (commercial) implications, e.g.: · '' cosmic weather '' forecast - predictions of geomagnetic disturbances related to Solar activity changes (due to large Solar Flares / events of Coronal Mass Ejection); these are important for large electricity networks, gas pipes, radio-wave connections, space missions and satellite experiments. Presentation of Cosmic Ray registration to high school students becomes a popular way to introduce particle physics detectors and elementary particle detection techniques to young people. We organize in Lodz several workshops on particle physics for high school students. This is a part of European activity: Masterclass - Hands on CERN. Energetic Cosmic Ray particles produce cascades of particles in the atmosphere, called Extensive Air Showers (EAS). Registering EAS and their properties is the main way of experimental studies of very high energy Cosmic Rays. In Lodz Department we run Extensive Air Shower array where EAS are continuously being registered. We concentrate on the studies of detection of neutrons correlated with EAS and interpretation of this phenomenon. Back in 2004 we started realisation of the Roland Maze Project, the network of EAS detectors

  6. Cosmic Ray Interactions in Shielding Materials

    International Nuclear Information System (INIS)

    Aguayo Navarrete, Estanislao; Kouzes, Richard T.; Ankney, Austin S.; Orrell, John L.; Berguson, Timothy J.; Troy, Meredith D.

    2011-01-01

    This document provides a detailed study of materials used to shield against the hadronic particles from cosmic ray showers at Earth's surface. This work was motivated by the need for a shield that minimizes activation of the enriched germanium during transport for the MAJORANA collaboration. The materials suitable for cosmic-ray shield design are materials such as lead and iron that will stop the primary protons, and materials like polyethylene, borated polyethylene, concrete and water that will stop the induced neutrons. The interaction of the different cosmic-ray components at ground level (protons, neutrons, muons) with their wide energy range (from kilo-electron volts to giga-electron volts) is a complex calculation. Monte Carlo calculations have proven to be a suitable tool for the simulation of nucleon transport, including hadron interactions and radioactive isotope production. The industry standard Monte Carlo simulation tool, Geant4, was used for this study. The result of this study is the assertion that activation at Earth's surface is a result of the neutronic and protonic components of the cosmic-ray shower. The best material to shield against these cosmic-ray components is iron, which has the best combination of primary shielding and minimal secondary neutron production.

  7. LHCf sheds new light on cosmic rays

    CERN Multimedia

    Anaïs Schaeffer

    2011-01-01

    The energy spectrum of the single photon obtained using data from the LHCf experiment has turned out to be very different from that predicted by the theoretical models used until now to describe the interactions between very high-energy cosmic rays and the earth's atmosphere. The consequences of this discrepancy for cosmic ray studies could be significant.   Artistic impression of cosmic rays entering Earth's atmosphere. (Credit: Asimmetrie/Infn). It took physicists by surprise when analysis of the data collected by the two LHCf calorimeters in 2010 showed that high-energy cosmic rays don't interact with the atmosphere in the manner predicted by theory. The LHCf detectors, set up 140 metres either side of the ATLAS interaction point, are dedicated to the study of the secondary particles emitted at very small angles during proton-proton collisions in the LHC, with energies comparable to cosmic rays entering the earth's atmosphere at 2.5x1016 eV. The aim of the experiment is to r...

  8. Department of Cosmic Ray Physics - Overview

    International Nuclear Information System (INIS)

    Szabelski, J.

    2008-01-01

    Full text: The Department of Cosmic Ray Physics in Lodz is involved in basic research in the high energy Cosmic Ray field. Cosmic Rays are energetic particles from outside the Solar System. Most of the studies of Cosmic Rays address fundamental problems: · the nature of the physical and astrophysical processes responsible for high energies of particles · an estimation of the astrophysical conditions at the acceleration sites and/or search for sources of Cosmic Rays, · properties of high energy particle interactions at very high energies. Some Cosmic Ray studies might have practical (commercial) implications, e.g. · '' cosmic weather '' forecast - predictions of geomagnetic disturbances related to Solar activity changes (due to large Solar Flares / events of Coronal Mass Ejection); these are important for large electricity networks, gas pipes, radio-wave connections, space missions and satellite experiments. Presentation of Cosmic Ray registration to high school students becomes a popular way to introduce particle physics detectors and elementary particle detection techniques to young people. We organize in Lodz several workshops on particle physics for high school students. This is a part of European activity: EPPOG's Masterclass - Hands on CERN. Energetic Cosmic Ray particles produce cascades of particles in the atmosphere, called Extensive Air Showers (EAS). Registering EAS and their properties is the main way of experimental studies of very high energy Cosmic Rays. In Lodz Department we run Extensive Air Shower array where EAS are continuously being registered. We concentrate on the studies of detection of neutrons correlated with EAS and interpretation of this phenomenon. In 2004 we started realisation of the Roland Maze Project, the network of EAS detectors placed on the roofs of high schools in Lodz. We received funds from the City of Lodz budget to make a pilot project and equip 10 high schools, each with four 1m 2 detectors and GPS. The network is

  9. Cosmic ray acceleration by shock waves in a diffusion medium. Research of high energies

    International Nuclear Information System (INIS)

    Lagage, P.O.

    1982-06-01

    The problem of galactic cosmic-ray acceleration is presented with the study of a new acceleration mechanism by supernova shock waves in a diffusive medium. The question is: do supernova shocks have enough time to accelerate cosmic rays beyond 10 4 -10 5 GeV. A firm upper limit to the energy that can be acquired by particles is established and it is considered that the mean free path of the particle has its lowest possible value and the most favorable model of supernova evolution. The diffusion coefficients which are relevant for the determination of the high energy cut off are investigated. The effect of the spatial dependence of the diffusion coefficient on the rate of acceleration of particles is examined. A more realistic cut off energy is calculated. We find E max = 2 10 4 GeV [fr

  10. New results from cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Tonwar, S. C.

    1980-07-01

    Behavior of elementary particles at very high energies and new phenomena observed are discussed in the light of results obtained by cosmic ray studies. Methods of determining hadron-nucleus inelastic cross-sections are described. Proton energy spectra are studied at 2000-50,000 GeV and the hadron-proton total cross section is deduced. Measurement of the cross-section by measurement of the intensity of transition radiation is described. The instrumental effects and the corrections effected are mentioned. The results obtained by different groups of investigators are compared. Observations on the scaling violation at high energies are reported. New particles or phenomena observed include: (i) the long flying component (ii) centauro events, (iii) delayed particles (iv) high energy cascades in underground experiments and (v) charm hadron production in hadron collisions. New experiments being planned for further research are mentioned.

  11. Measuring extensive air showers with Cherenkov light detectors of the Yakutsk array: the energy spectrum of cosmic rays

    International Nuclear Information System (INIS)

    Ivanov, A A; Knurenko, S P; Sleptsov, I Ye

    2009-01-01

    The energy spectrum of cosmic rays in the range E∼10 15 eV to 6x10 19 eV is studied in this paper using air Cherenkov light detectors of the Yakutsk array. The total flux of photons produced by the relativistic electrons (including positrons as well, hereafter) of extensive air showers in the atmosphere is used as an energy estimator of the primary particle initiating a shower. The resultant differential flux of cosmic rays exhibits, in agreement with previous measurements, a knee and ankle feature at energies of 3x10 15 and ∼10 19 eV, respectively. A comparison of observational data with simulations is made in the knee and ankle regions in order to choose the models of galactic and extragalactic components of cosmic rays that describe well the energy spectrum measured.

  12. Measuring extensive air showers with Cherenkov light detectors of the Yakutsk array: the energy spectrum of cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, A A; Knurenko, S P; Sleptsov, I Ye [Shafer Institute for Cosmophysical Research and Aeronomy, Yakutsk 677980 (Russian Federation)], E-mail: ivanov@ikfia.ysn.ru

    2009-06-15

    The energy spectrum of cosmic rays in the range E{approx}10{sup 15} eV to 6x10{sup 19} eV is studied in this paper using air Cherenkov light detectors of the Yakutsk array. The total flux of photons produced by the relativistic electrons (including positrons as well, hereafter) of extensive air showers in the atmosphere is used as an energy estimator of the primary particle initiating a shower. The resultant differential flux of cosmic rays exhibits, in agreement with previous measurements, a knee and ankle feature at energies of 3x10{sup 15} and {approx}10{sup 19} eV, respectively. A comparison of observational data with simulations is made in the knee and ankle regions in order to choose the models of galactic and extragalactic components of cosmic rays that describe well the energy spectrum measured.

  13. Cosmic rays: an in-flight hazard?

    International Nuclear Information System (INIS)

    O'Sullivan, Denis

    2000-01-01

    International airlines are collaborating with physicists to assess whether aircrew are at risk from cosmic radiation as routine monitoring will soon become mandatory. Recently, an international team of physicists has joined forces with NASA and several European airlines to study in detail how the radiation field varies inside the atmosphere depending on the altitude, latitude and solar activity. Astronauts are subjected to the full intensity of high-energy cosmic rays and solar particles (together with the secondary particles produced in the spacecraft walls), and the biological risks in space are the subject of ongoing investigations. A typical return mission to Mars, for example, could result in a total ''dose equivalent'' of up to 0.5 sievert. The dose equivalent takes into account the harm caused by a particular type of radiation. Current estimates suggest that a person who receives a 1 sievert dose of ionizing radiation incurs a few per cent increase in the risk of contracting fatal cancer in his or her lifetime, although the risk level depends on sex and age. The radiation we observe at aircraft altitudes of typically 10-12 km is due to very high-energy particles mainly protons and helium nuclei, together with a small amount of heavy nuclei penetrating the atmosphere and colliding with air atoms. These collisions give rise to the production of more particles, such as protons, neutrons and various mesons. A cascade of particles is then produced by successive interactions as they penetrate deeper into the atmosphere. As a result, the flux of particles increases in the upper atmosphere and reaches a maximum at about 20 km above sea level. Below this point, the number of particles decreases due to energy losses and various particle interactions. Happily, at the Earth's surface we are protected by the air above us, which provides the same degree of shielding as a layer of water 10 m thick. The small amount of radiation that eventually reaches us in the form of

  14. Cosmic rays and ancient planetary magnetic fields

    International Nuclear Information System (INIS)

    Wesson, P.S.

    1977-01-01

    The possibility is discussed of using the latitude-dependent cutoff in the intensity and flux of cosmic ray particles reaching the surface of a planet to investigate ancient magnetic fields in the Moon, Mars and the Earth. In the last case, the method could provide a validity test for conventional palaeomagnetism. (Auth.)

  15. Ultrahigh energy cosmic rays and neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Stanev, Todor [Bartol Research Foundation, Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States)], E-mail: stanev@bartol.udel.edu

    2008-04-01

    We discuss the relation between the highest energy cosmic rays (UHECR) and UHE neutrinos. The neutrinos produced in the sources of optically thin astrophysical sources have been linked to the UHECR emissivity of the Universe. The fluxes of cosmogenic neutrinos, generated in propagation by UHECR, also reflect the acceleration of these particles, the maximum acceleration energy, and the cosmological evolution of their sources.

  16. Heliospheric Impact on Cosmic Rays Modulation

    Science.gov (United States)

    Tiwari, Bhupendra Kumar

    2016-07-01

    Heliospheric Impact on Cosmic RaysModulation B. K. Tiwari Department of Physics, A. P. S. University, Rewa (M.P.), btiwari70@yahoo.com Cosmic rays (CRs) flux at earth is modulated by the heliosphereric magnetic field and the structure of the heliosphere, controls by solar outputs and their variability. Sunspots numbers (SSN) is often treated as a primary indicator of solar activity (SA). GCRs entering the helioshphere are affected by the interplanetary magnetic field (IMF) and solar wind speed, their modulation varies with the varying solar activity. The observation based on data recoded from Omniweb data Centre for solar- interplanetary activity indices and monthly mean count rate of cosmic ray intensity (CRI) data from neutron monitors of different cut-off rigidities(Rc) (Moscow Rc=2.42Gv and Oulu Rc=0.80Gv). During minimum solar activity periodof solar cycle 23/24, the sun is remarkably quiet, weakest strength of the IMF and least dense and slowest, solar wind speed, whereas, in 2003, highest value of yearly averaged solar wind speed (~568 Km/sec) associated with several coronal holes, which generate high speed wind stream has been recorded. It is observed that GCRs fluxes reduces and is high anti-correlated with SSN (0.80) and IMF (0.86). CRI modulation produces by a strong solar flare, however, CME associated solar flare produce more disturbance in the interplanetary medium as well as in geomagnetic field. It is found that count rate of cosmic ray intensity and solar- interplanetary parameters were inverse correlated and solar indices were positive correlated. Keywords- Galactic Cosmic rays (GCRs), Sunspot number (SSN), Solar activity (SA), Coronal Mass Ejection (CME), Interplanetary magnetic field (IMF)

  17. Department of Cosmic Ray Physics - Overview

    International Nuclear Information System (INIS)

    Szabelski, J

    2005-01-01

    Full text: The Department of Cosmic Ray Physics in Lodz is involved in basic research in the high energy Cosmic Ray field. Cosmic Rays are energetic particles from outside the Solar System. The energy spectrum (power law energy dependence) suggests a non-thermal origin of these particles. Most studies of Cosmic Rays address fundamental problems: - the nature of the physical and astrophysical processes responsible for high energies of particles (up to about 10 20 eV/particle), - estimation of the astrophysical conditions at the acceleration sites and/or search for sources of Cosmic Rays, - properties of high energy particle interactions at very high energies (nuclear interactions at energies exceeding energy available in laboratories). - Some Cosmic Ray studies might have practical (commercial) implications, e.g. - ''cosmic weather'' forecast - predictions of geomagnetic disturbances related to Solar activity changes (due to large Solar Flares / events of Coronal Mass Ejection); these are important for large electricity networks, gas pipes, radio-wave connections, space missions and satellite experiments. Presentation of Cosmic Ray registration to high school students is a popular way to introduce particle physics detectors and elementary particle detection techniques to young people. Energetic Cosmic Ray particles produce cascades of particles in the atmosphere, called Extensive Air Showers (EAS). Registering the EAS and their properties is the main way of experimental studies of very high energy Cosmic Rays. In our Lodz Department we run an Extensive Air Shower array where EAS are continuously being registered. We concentrate on the studies of detection of neutrons correlated with EAS and interpretation of this phenomenon. In 2004 we started realisation of the Roland Maze Project, the network of EAS detectors placed on the roofs of high schools in Lodz. We received funds from the City of Lodz's budget to make a pilot project and equip 10 high schools, each with

  18. Department of Cosmic Ray Physics - Overview

    International Nuclear Information System (INIS)

    Szabelski, J.

    2006-01-01

    The Department of Cosmic Ray Physics in Lodz is involved in basic research in the high energy Cosmic Ray field. Cosmic Rays are energetic particles from outside the Solar System. The energy spectrum (power law energy dependence) suggests a non-thermal origin of these particles. Most of the studies of Cosmic Rays address fundamental problems: · The nature of the physical and astrophysical processes responsible for the high energies of the particles (up to about 1020 eV/particle), · An estimation of the astrophysical conditions at the acceleration sites and/or search for sources of Cosmic Rays, · properties of high energy particle interactions at very high energies (nuclear interactions at energies exceeding energy available in the laboratories). Some Cosmic Ray studies might have practical (commercial) implications, e.g. · 'cosmic weather' forecast - predictions of geomagnetic disturbances related to Solar activity changes (due to large Solar Flares / events of Coronal Mass Ejection); these are important for large electricity networks, gas pipes, radio-wave connections, space missions and satellite experiments. Presentation of Cosmic Ray registration to high school students becomes a popular way to introduce particle physics detectors and elementary particle detection techniques to young people. Energetic Cosmic Ray particles produce cascades of particles in the atmosphere, called Extensive Air Showers (EAS). Registering EAS and their properties is the main way of experimental studies of very high energy Cosmic Rays. In the Lodz Department we run the Extensive Air Shower array where EAS are being registered. We concentrate on the studies of detection of neutrons correlated with EAS and interpretation of this phenomenon. In 2004, we started realisation of the Roland Maze Project, the network of EAS detectors placed on roofs of high schools in Lodz. We received funds from the City of Lodz budget to make a pilot project and equip 10 high schools, each with four 1 m

  19. Studies in cosmic rays

    International Nuclear Information System (INIS)

    Bemalkhedkar, M.M.

    1974-03-01

    The investigation of the diurnal variation in the cosmic ray intensity on individual days has revealed a new class of diurnal variation showing a maximum around 09 hour direction in the interplanetary space. It is shown to occur during the recovery phase of Forbush decreases as well as during quiet periods. The rigidity spectrum of the anomalous diurnal variation has an exponent around zero, the same as that for the average diurnal variation exhibiting maximum around 18 hours in the interplanetary space. It is shown that the Forbush decreases associated with the diurnal variation exhibiting morning maximum, are 27 day recurrent in nature and are preceded by east limb solar flares on most of the occasions. A qualitative model of the transient modulation by solar corotating corpuscular streams of enhanced solar wind velocity, emanating from the active regions on the solar disc, is proposed to explain the anomalous diurnal anisotropy in the recovery phase of 27 day recurrent Forbush decreases. From this model, the cosmic ray diffusion coefficients, parallel and perpendicular to the interplanetary magnetic field inside the corotating stream, are derived and compared with the average values. To investigate the possibility of determining the energy spectra of cosmic ray intensity variations from a single station, a continuous record of neutron multiplicity spectrum has been obtained for the period October, 1967 - October, 1971, using the Gulmarg neutron monitor. The average multiplicity spectrum in the Gulmarg neutron monitor shows a mean multiplicity approximately equal to 1.4 for 12 Boron-tri-fluoride counters and is an increasing function of the number of counters used. The mean multiplicity measured in various other neutron monitors, when normalized to the cutoff rigidity of Gulmurg (11.91 GV), shows a systematic increase with the altitude of the station. (author)

  20. Development of the radio astronomical method of cosmic particle detection for extremely high-energy cosmic ray physics and neutrino astronomy

    Directory of Open Access Journals (Sweden)

    Zheleznykh Igor

    2017-01-01

    Full Text Available The proposal to use ground based radio telescopes for detection of Askaryan radio pulses from particle cascades arising when extremely high-energy (EHE > 1020 eV cosmic rays (including neutrinos interact with the lunar regolith of multi gigaton mass was made at the end of 1980s in the framework of the Russian (Soviet DUMAND Program. During more than a quarter of century a number of lunar experiments were carried out mainly in the 1–3 GHz frequency range using the large radio telescopes of Australia, USA, Russia and other countries but these experiments only put upper limits to the EHE cosmic rays fluxes. For this reason, it would be of great interest to search for nanosecond radio pulses from the Moon in a wider interval of frequencies (including lower ones of 100–350 MHz with larger radio detectors – for example the giant radio telescope SKA (Square Kilometer Array which is constructed in Australia, New Zealand and South Africa. In this paper possibilities are discussed to use one of the most sensitive meter-wavelength (∼ 110 MHz Large Phased Array (LPA of 187 × 384 m2 and the wide field of view meter-wavelength array of the Pushchino Radio Astronomy Observatory as prototypes of low frequency radio detectors for lunar experiments. The new scheme for fast simulation of ultrahigh and extremely high-energy cascades in dense media is also suggested. This scheme will be used later for calculations of radio emission of cascades in the lunar regolith with energies up to 1020 eV and higher in the wide frequency band of 0.1− a few GHz.

  1. First results of the cosmic ray NUCLEON experiment

    Energy Technology Data Exchange (ETDEWEB)

    Atkin, E.; Shumikhin, V. [National Research Nuclear University ' MEPhI' , Kashirskoe highway 31, Moscow, 115409 (Russian Federation); Bulatov, V., E-mail: evatkin@mephi.ru, E-mail: shuma.v.v@mail.ru, E-mail: bulat@horizont.e-burg.ru [SDB Automatika, Mamin-Sibiryak str. 145, Ekaterinburg, 620075 (Russian Federation); and others

    2017-07-01

    The NUCLEON experiment was designed to study the chemical composition and energy spectra of galactic cosmic ray nuclei from protons to zinc at energies of ∼ 10{sup 11}–10{sup 15} eV per particle. The research was carried out with the NUCLEON scientific equipment installed on the Russian satellite 'Resource-P' No. 2 as an additional payload. This article presents the results for the measured nuclei spectra related to the first approximately 250 days of the scientific data collection during 2015 and 2016. The all-particle spectrum and the spectra of p, He, C, O, Ne, Mg, Si and Fe are presented. Some interesting ratios of the spectra are also presented and discussed. The experiment is now in its beginning stage and the data still have a preliminary character, but they already give numerous indications of the existence of various non-canonical phenomena in the physics of cosmic rays, which are expressed in the violation of a simple universal power law of the energy spectra. These features of the data are briefly discussed.

  2. New look on the origin of cosmic rays

    Directory of Open Access Journals (Sweden)

    Istomin Ya.N.

    2017-01-01

    Full Text Available From the analysis of the flux of high energy particles, E > 3 · 1018 eV, it is shown that the distribution of the power density of extragalactic rays over energy is of the power law, q̅(E ∝ E−2.7, with the same index of 2.7 that has the distribution of Galactic cosmic rays before the so called ‘knee', E 3 · 1015 eV, from the Galaxy because of the dependence of the coefficient of diffusion of cosmic rays on energy, D∝E0.7. The obtained index of the density distribution of particles over energy, N(E∝E−2.7−0.7/2=E−3.05, for E > 3 · 1015 eV agrees well with the observed one, N(E∝E−3.1. The estimated time of the termination of the jet in the Galaxy is 4.2 · 104 years ago.

  3. First results of the cosmic ray NUCLEON experiment

    International Nuclear Information System (INIS)

    Atkin, E.; Shumikhin, V.; Bulatov, V.

    2017-01-01

    The NUCLEON experiment was designed to study the chemical composition and energy spectra of galactic cosmic ray nuclei from protons to zinc at energies of ∼ 10 11 –10 15 eV per particle. The research was carried out with the NUCLEON scientific equipment installed on the Russian satellite 'Resource-P' No. 2 as an additional payload. This article presents the results for the measured nuclei spectra related to the first approximately 250 days of the scientific data collection during 2015 and 2016. The all-particle spectrum and the spectra of p, He, C, O, Ne, Mg, Si and Fe are presented. Some interesting ratios of the spectra are also presented and discussed. The experiment is now in its beginning stage and the data still have a preliminary character, but they already give numerous indications of the existence of various non-canonical phenomena in the physics of cosmic rays, which are expressed in the violation of a simple universal power law of the energy spectra. These features of the data are briefly discussed.

  4. Cosmic ray: Studying the origin

    International Nuclear Information System (INIS)

    Szabelski, J.

    1997-01-01

    Investigations of the origin of cosmic rays are presented. Different methods are discussed: studies of cosmic gamma rays of energy from 30 MeV to about 10 15 eV (since photons point to their places of origin), studies of the mass composition of cosmic rays (because it reflects source morphology), and studies of cosmic rays with energy above 1O 19 eV (for these are the highest energies observed in nature). (author)

  5. Department of Cosmic Ray Physics - Overview

    International Nuclear Information System (INIS)

    Szabelski, J.

    2009-01-01

    Full text: The Department of Cosmic Ray Physics in Lodz is involved in basic research in the high-energy Cosmic Ray field. Cosmic Rays are energetic particles from outside the Solar System. Most of the studies of Cosmic Rays address fundamental problems: - the nature of the physical and astrophysical processes responsible for the high energies of the particles - an estimation of the astrophysical conditions at the acceleration sites and/or the search for sources of Cosmic Rays, - properties of high-energy particle interactions at very high energies. Some Cosmic Ray studies might have practical (commercial) implications, e.g. - '' cosmic weather '' forecasting - predictions of geomagnetic disturbances related to Solar activity changes (due to large Solar Flares/Coronal Mass Ejection events); these are important for large electricity networks, gas pipelines, radio-wave connections, space missions and satellite experiments. Presentation of Cosmic Ray registration to high school students has become a popular way to introduce particle physics detectors and elementary particle detection techniques to young people. We organize in Lodz and Poznan workshops on particle physics for high school students. This is a part of the European activity: EPPOG's Masterclass - Hands on CERN. Energetic Cosmic Ray particles produce cascades of particles in the atmosphere, called Extensive Air Showers (EAS). Registering EAS and their properties is the main way of experimentally study's very high energy Cosmic Rays. Locally in Lodz we concentrate on methodological studies of the detection of neutrons correlated with EAS and the interpretation of this phenomenon. We have also performed two series of neutron background measurements in the deep underground Gran Sasso Laboratory in Italy (within the ILIAS-TA Project). In 2004, we began the Roland Maze Project, a network of EAS detectors placed on the roofs of high schools in Lodz. The pilot project is to equip 10 high schools, each with four 1m

  6. Generation of mesoscale magnetic fields and the dynamics of Cosmic Ray acceleration

    Science.gov (United States)

    Diamond, P. H.; Malkov, M. A.

    The problem of the cosmic ray origin is discussed in connection with their acceleration in supernova remnant shocks. The diffusive shock acceleration mechanism is reviewed and its potential to accelerate particles to the maximum energy of (presumably) galactic cosmic rays (1018eV ) is considered. It is argued that to reach such energies, a strong magnetic field at scales larger than the particle gyroradius must be created as a result of the acceleration process, itself. One specific mechanism suggested here is based on the generation of Alfven wave at the gyroradius scale with a subsequent transfer to longer scales via interaction with strong acoustic turbulence in the shock precursor. The acoustic turbulence in turn, may be generated by Drury instability or by parametric instability of the Alfven waves. The generation mechanism is modulational instability of CR generated Alfven wave packets induced, in turn, by scattering off acoustic fluctuations in the shock precursor which are generated by Drury instability.

  7. Pulsar Wind Nebulae and Cosmic Rays: A Bedtime Story

    Energy Technology Data Exchange (ETDEWEB)

    Weinstein, A.

    2014-11-15

    The role pulsar wind nebulae play in producing our locally observed cosmic ray spectrum remains murky, yet intriguing. Pulsar wind nebulae are born and evolve in conjunction with SNRs, which are favored sites of Galactic cosmic ray acceleration. As a result they frequently complicate interpretation of the gamma-ray emission seen from SNRs. However, pulsar wind nebulae may also contribute directly to the local cosmic ray spectrum, particularly the leptonic component. This paper reviews the current thinking on pulsar wind nebulae and their connection to cosmic ray production from an observational perspective. It also considers how both future technologies and new ways of analyzing existing data can help us to better address the relevant theoretical questions. A number of key points will be illustrated with recent results from the VHE (E > 100 GeV) gamma-ray observatory VERITAS.

  8. Cosmic rays at ultra high energies (Neutrinos.)

    International Nuclear Information System (INIS)

    Ahlers, M.; Ringwald, A.; Tu, H.

    2005-06-01

    Resonant photopion production with the cosmic microwave background predicts a suppression of extragalactic protons above the famous Greisen-Zatsepin-Kuzmin cutoff at about E GZK ∼ 5 x 10 10 GeV. Current cosmic ray data measured by the AGASA and HiRes Collaborations do not unambiguously confirm the GZK cutoff and leave a window for speculations about the origin and chemical composition of the highest energy cosmic rays. In this work we analyze the possibility of strongly interacting neutrino primaries and derive model-independent quantitative requirements on the neutrino-nucleon inelastic cross section for a viable explanation of the cosmic ray data. Search results on weakly interacting cosmic particles from the AGASA and RICE experiments are taken into account simultaneously. Using a flexible parameterization of the inelastic neutrino-nucleon cross section we find that a combined fit of the data does not favor the Standard Model neutrino-nucleon inelastic cross section, but requires, at 90% confidence level, a steep increase within one energy decade around E GZK by four orders of magnitude. We illustrate such an enhancement within some extensions of the Standard Model. The impact of new cosmic ray data or cosmic neutrino search results on this scenario, notably from the Pierre Auger Observatory soon, can be immediately evaluated within our approach. (orig.)

  9. Cosmic-Ray Extremely Distributed Observatory: a global cosmic ray detection framework

    Science.gov (United States)

    Sushchov, O.; Homola, P.; Dhital, N.; Bratek, Ł.; Poznański, P.; Wibig, T.; Zamora-Saa, J.; Almeida Cheminant, K.; Alvarez Castillo, D.; Góra, D.; Jagoda, P.; Jałocha, J.; Jarvis, J. F.; Kasztelan, M.; Kopański, K.; Krupiński, M.; Michałek, M.; Nazari, V.; Smelcerz, K.; Smolek, K.; Stasielak, J.; Sułek, M.

    2017-12-01

    The main objective of the Cosmic-Ray Extremely Distributed Observatory (CREDO) is the detection and analysis of extended cosmic ray phenomena, so-called super-preshowers (SPS), using existing as well as new infrastructure (cosmic-ray observatories, educational detectors, single detectors etc.). The search for ensembles of cosmic ray events initiated by SPS is yet an untouched ground, in contrast to the current state-of-the-art analysis, which is focused on the detection of single cosmic ray events. Theoretical explanation of SPS could be given either within classical (e.g., photon-photon interaction) or exotic (e.g., Super Heavy Dark Matter decay or annihilation) scenarios, thus detection of SPS would provide a better understanding of particle physics, high energy astrophysics and cosmology. The ensembles of cosmic rays can be classified based on the spatial and temporal extent of particles constituting the ensemble. Some classes of SPS are predicted to have huge spatial distribution, a unique signature detectable only with a facility of the global size. Since development and commissioning of a completely new facility with such requirements is economically unwarranted and time-consuming, the global analysis goals are achievable when all types of existing detectors are merged into a worldwide network. The idea to use the instruments in operation is based on a novel trigger algorithm: in parallel to looking for neighbour surface detectors receiving the signal simultaneously, one should also look for spatially isolated stations clustered in a small time window. On the other hand, CREDO strategy is also aimed at an active engagement of a large number of participants, who will contribute to the project by using common electronic devices (e.g., smartphones), capable of detecting cosmic rays. It will help not only in expanding the geographical spread of CREDO, but also in managing a large manpower necessary for a more efficient crowd-sourced pattern recognition scheme to

  10. Long-lived staus from cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Ahlers, M. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Illana, J.I.; Masip, M. [Granada Univ. (Spain). CAFPE y Dept. de Fisica Teorica y del Cosmos; Meloni, D. [Univ. degli Studi di Roma La Spienza (Italy). Dipt. di Fisica; INFN, Roma (Italy)

    2007-05-15

    The collision of a high energy cosmic ray with a nucleon in the upper atmosphere could produce long-lived heavy particles. Such particles would be very penetrating, since the energy loss in matter scales as the inverse mass, and could reach a neutrino telescope like IceCube from large zenith angles. Here we study this possibility and focus on the long-lived stau of SUSY models with a gravitino LSP. The signal would be a pair of muon-like parallel tracks separated by 50 meters along the detector. We evaluate the background of muon pairs and show that any events from zenith angles above 80. could be explained by the production of these heavy particles by cosmic rays. (orig.)

  11. Direct cosmic ray muons and atmospheric neutrinos

    International Nuclear Information System (INIS)

    Ryazhskaya, O.G.; Volkova, L.V.; Zatsepin, G.T.

    2005-01-01

    A possible contribution of very short living particles (particles with life-time much shorter than that of charmed particles), for example, resonances, into cosmic ray muon and atmospheric neutrino fluxes (direct muons and neutrinos) is estimated. This contribution could become of the same order of magnitude as that from pions and kaons (conventional) already at energies of hundreds TeV and tens TeV for muons and muon neutrinos coming to the sea level in the vertical direction correspondingly. Of course, the estimation has quite a qualitative character and even it is quite arbitrary but it is necessary to keep this contribution in mind when studying EAS, cosmic ray muon component or trying to interpret data of experiments on cosmic neutrino searching at high energies

  12. Long-lived staus from cosmic rays

    International Nuclear Information System (INIS)

    Ahlers, M.; Illana, J.I.; Masip, M.

    2007-05-01

    The collision of a high energy cosmic ray with a nucleon in the upper atmosphere could produce long-lived heavy particles. Such particles would be very penetrating, since the energy loss in matter scales as the inverse mass, and could reach a neutrino telescope like IceCube from large zenith angles. Here we study this possibility and focus on the long-lived stau of SUSY models with a gravitino LSP. The signal would be a pair of muon-like parallel tracks separated by 50 meters along the detector. We evaluate the background of muon pairs and show that any events from zenith angles above 80. could be explained by the production of these heavy particles by cosmic rays. (orig.)

  13. Transition-radiation detectors for cosmic-ray research

    International Nuclear Information System (INIS)

    Mueller, D.; Chicago Univ., Ill.

    1975-01-01

    Transition-radiation detectors for cosmic-ray work are described which consist of plastic foam of multiple plastic foil radiators, followed by proportional chambers. A summary of the properties of such detectors is given, and the detection and discrimination efficiencies for energetic particles are discussed. Several possible applications of such devices for studies of cosmic-ray particles in the energy region γ=E/mc 2 >10 3 are advertised

  14. Cosmic rays and the search for a Lorentz Invariance Violation

    Energy Technology Data Exchange (ETDEWEB)

    Bietenholz, Wolfgang, E-mail: wolbi@nucleares.unam.mx

    2011-08-15

    This is an introductory review about the ongoing search for a signal of Lorentz Invariance Violation (LIV) in cosmic rays. We first summarise basic aspects of cosmic rays, focusing on rays of ultrahigh energy (UHECRs). We discuss the Greisen-Zatsepin-Kuz'min (GZK) energy cutoff for cosmic protons, which is predicted due to photopion production in the Cosmic Microwave Background (CMB). This is a process of modest energy in the proton rest frame. It can be investigated to a high precision in the laboratory, if Lorentz transformations apply even at factors {gamma}{approx}O(10{sup 11}). For heavier nuclei, the energy attenuation is even faster due to photo-disintegration, again if this process is Lorentz invariant. Hence the viability of Lorentz symmetry up to tremendous {gamma}-factors-far beyond accelerator tests-is a central issue. Next, we comment on conceptual aspects of Lorentz Invariance and the possibility of its spontaneous breaking. This could lead to slightly particle dependent 'Maximal Attainable Velocities'. We discuss their effect in decays, Cerenkov radiation, the GZK cutoff and neutrino oscillation in cosmic rays. We also review the search for LIV in cosmic {gamma}-rays. For multi-TeV {gamma}-rays, we encounter another possible puzzle related to the transparency of the CMB, similar to the GZK cutoff, due to electron/positron creation and subsequent inverse Compton scattering. The photons emitted in a Gamma Ray Burst occur at lower energies, but their very long path provides access to information not that far from the Planck scale. We discuss conceivable nonlinear photon dispersions based on non-commutative geometry or effective approaches. No LIV has been observed so far. However, even extremely tiny LIV effects could change the predictions for cosmic ray physics drastically. An Appendix is devoted to the recent results by the Pierre Auger Collaboration, in particular the hypothesis that nearby Active Galactic Nuclei-or objects next to

  15. Cosmic rays and the search for a Lorentz Invariance Violation

    Energy Technology Data Exchange (ETDEWEB)

    Bietenholz, Wolfgang [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC

    2008-11-15

    This is an introductory review about the on-going search for a signal of Lorentz Invariance Violation (LIV) in cosmic rays. We first summarise basic aspects of cosmic rays, focusing on rays of ultra high energy (UHECRs). We discuss the Greisen-Zatsepin-Kuz'min (GZK) energy cutoff for cosmic protons, which is predicted due to photopion production in the Cosmic Microwave Background (CMB). This is a process of modest energy in the proton rest frame. It can be investigated to a high precision in the laboratory, if Lorentz transformations apply even at factors {gamma} {proportional_to} O(10{sup 11}). For heavier nuclei the energy attenuation is even faster due to photo-disintegration, again if this process is Lorentz invariant. Hence the viability of Lorentz symmetry up to tremendous {gamma}-factors - far beyond accelerator tests - is a central issue. Next we comment on conceptual aspects of Lorentz Invariance and the possibility of its spontaneous breaking. This could lead to slightly particle dependent ''Maximal Attainable Velocities''. We discuss their effect in decays, Cerenkov radiation, the GZK cutoff and neutrino oscillation in cosmic rays. We also review the search for LIV in cosmic {gamma}-rays. For multi TeV {gamma}-rays we possibly encounter another puzzle related to the transparency of the CMB, similar to the GZK cutoff, due to electron/positron creation and subsequent inverse Compton scattering. The photons emitted in a Gamma Ray Burst occur at lower energies, but their very long path provides access to information not far from the Planck scale. We discuss conceivable non-linear photon dispersions based on non-commutative geometry or effective approaches. No LIV has been observed so far. However, even extremely tiny LIV effects could change the predictions for cosmic ray physics drastically. An Appendix is devoted to the recent hypothesis by the Pierre Auger Collaboration, which identifies nearby Active Galactic Nuclei - or objects

  16. Dark matter indirect detection with charged cosmic rays

    International Nuclear Information System (INIS)

    Giesen, Gaelle

    2015-01-01

    Overwhelming evidence for the existence of Dark Matter (DM), in the form of an unknown particle filling the galactic halos, originates from many observations in astrophysics and cosmology: its gravitational effects are apparent on galactic rotations, in galaxy clusters and in shaping the large scale structure of the Universe. On the other hand, a non-gravitational manifestation of its presence is yet to be unveiled. One of the most promising techniques is the one of indirect detection, aimed at identifying excesses in cosmic ray fluxes which could possibly be produced by DM annihilations or decays in the Milky Way halo. The current experimental efforts mainly focus in the GeV to TeV energy range, which is also where signals from WIMPs (Weakly Interacting Massive Particles) are expected. Focussing on charged cosmic rays, in particular antiprotons, electrons and positrons, as well as their secondary emissions, an analysis of current and foreseen cosmic ray measurements and improvements on astrophysical models are presented. Antiproton data from PAMELA imposes constraints on annihilating and decaying DM which are similar to (or even slightly stronger than) the most stringent bounds from gamma ray experiments, even when kinetic energies below 10 GeV are discarded. However, choosing different sets of astrophysical parameters, in the form of propagation models and halo profiles, allows the constraints to span over one or two orders of magnitude. In order to exploit fully the power of antiprotons to constrain or discover DM, effects which were previously perceived as sub-leading turn out to be relevant especially for the analysis of the newly released AMS-02 data. In fact, including energy losses, diffusive re-acceleration and solar modulation can somewhat modify the current bounds, even at large DM masses. A wrong interpretation of the data may arise if they are not taken into account. Finally, using the updated proton and helium fluxes just released by the AMS-02

  17. Long-term Modulation of Cosmic Ray Intensity in relation to Sunspot ...

    Indian Academy of Sciences (India)

    it should be more closely connected with cosmic ray modulation than with other solar characteristics (sunspot numbers or coronal emission intensity). The intensity of galactic cosmic rays varies inversely with sunspot numbers, having their maximum intensity at the minimum of the 11-year sunspot cycle (Forbush 1954, 1958) ...

  18. The TeV-scale cosmic ray proton and helium spectra

    Indian Academy of Sciences (India)

    2016-01-07

    Jan 7, 2016 ... Recent measurements of cosmic ray proton and helium spectra show a hardening above a few hundreds of GeV. This excess is hard to understand in the framework of the conventional models of galactic cosmic ray production and propagation. Here, we propose to explain this anomaly by the presence of ...

  19. The role of cosmic rays in the atmospheric processes

    Energy Technology Data Exchange (ETDEWEB)

    Stozhkov, Y I [Lebedev Physical Institute, Russian Academy of Sciences, 119991, Leninsky Prospect, 53, Moscow (Russian Federation)

    2003-05-01

    The energy flux of galactic cosmic rays falling on the earth's atmosphere is small in comparison with solar electromagnetic irradiation (by 10{sup 8} times). But at altitudes of h {approx} 3 to 35 km in the atmosphere, cosmic rays are the only ionization source (from the ground level up to h {approx} 3 km, natural radioactivity is an additional source of ionization). Solar activity modulates cosmic ray flux. The cosmic rays produce atmospheric ions that define the electrical properties of the atmosphere. The electric charges play a very important role in the processes of cloud and thundercloud formation in the operation of the global electric circuit. The changes in electric properties of the atmosphere influence weather and climate. Thus, we have the following chain of the solar terrestrial relationship: solar activity - cosmic ray modulation - changes in the global electric properties of the atmosphere - changes in weather and climate. The following questions are discussed in this paper: light ion production in the atmosphere, role of electric charges in the formation of clouds and thunderclouds, experimental evidences of the relationships between cosmic ray flux and atmospheric current and lightning.

  20. The role of cosmic rays in the atmospheric processes

    International Nuclear Information System (INIS)

    Stozhkov, Y I

    2003-01-01

    The energy flux of galactic cosmic rays falling on the earth's atmosphere is small in comparison with solar electromagnetic irradiation (by 10 8 times). But at altitudes of h ∼ 3 to 35 km in the atmosphere, cosmic rays are the only ionization source (from the ground level up to h ∼ 3 km, natural radioactivity is an additional source of ionization). Solar activity modulates cosmic ray flux. The cosmic rays produce atmospheric ions that define the electrical properties of the atmosphere. The electric charges play a very important role in the processes of cloud and thundercloud formation in the operation of the global electric circuit. The changes in electric properties of the atmosphere influence weather and climate. Thus, we have the following chain of the solar terrestrial relationship: solar activity - cosmic ray modulation - changes in the global electric properties of the atmosphere - changes in weather and climate. The following questions are discussed in this paper: light ion production in the atmosphere, role of electric charges in the formation of clouds and thunderclouds, experimental evidences of the relationships between cosmic ray flux and atmospheric current and lightning

  1. Practical Applications of Cosmic Ray Science: Spacecraft, Aircraft, Ground-Based Computation and Control Systems, and Human Health and Safety

    Science.gov (United States)

    Atwell, William; Koontz, Steve; Normand, Eugene

    2012-01-01

    Three twentieth century technological developments, 1) high altitude commercial and military aircraft; 2) manned and unmanned spacecraft; and 3) increasingly complex and sensitive solid state micro-electronics systems, have driven an ongoing evolution of basic cosmic ray science into a set of practical engineering tools needed to design, test, and verify the safety and reliability of modern complex technological systems. The effects of primary cosmic ray particles and secondary particle showers produced by nuclear reactions with the atmosphere, can determine the design and verification processes (as well as the total dollar cost) for manned and unmanned spacecraft avionics systems. Similar considerations apply to commercial and military aircraft operating at high latitudes and altitudes near the atmospheric Pfotzer maximum. Even ground based computational and controls systems can be negatively affected by secondary particle showers at the Earth s surface, especially if the net target area of the sensitive electronic system components is large. Finally, accumulation of both primary cosmic ray and secondary cosmic ray induced particle shower radiation dose is an important health and safety consideration for commercial or military air crews operating at high altitude/latitude and is also one of the most important factors presently limiting manned space flight operations beyond low-Earth orbit (LEO). In this paper we review the discovery of cosmic ray effects on the performance and reliability of microelectronic systems as well as human health and the development of the engineering and health science tools used to evaluate and mitigate cosmic ray effects in ground-based atmospheric flight, and space flight environments. Ground test methods applied to microelectronic components and systems are used in combinations with radiation transport and reaction codes to predict the performance of microelectronic systems in their operating environments. Similar radiation transport

  2. Cosmic ray: Studying the origin

    Energy Technology Data Exchange (ETDEWEB)

    Szabelski, J. [Cosmic Ray Laboratory, Soltan Institute for Nuclear Studies, Lodz (Poland)

    1997-12-31

    Investigations of the origin of cosmic rays are presented. Different methods are discussed: studies of cosmic gamma rays of energy from 30 MeV to about 10{sup 15} eV (since photons point to their places of origin), studies of the mass composition of cosmic rays (because it reflects source morphology), and studies of cosmic rays with energy above 1O{sup 19} eV (for these are the highest energies observed in nature). (author) 101 refs, 19 figs, 7 tabs

  3. A Critical Shock Mach Number for Particle Acceleration in the Absence of Pre-existing Cosmic Rays: M = √5

    NARCIS (Netherlands)

    Vink, J.; Yamazaki, R.

    2014-01-01

    It is shown that, under some generic assumptions, shocks cannot accelerate particles unless the overall shock Mach number exceeds a critical value M > √5. The reason is that for M ≤ √5 the work done to compress the flow in a particle precursor requires more enthalpy flux than the system can sustain.

  4. Cosmic Ray Signatures of Decaying Dark Matter

    International Nuclear Information System (INIS)

    Ibarra, Alejandro

    2011-01-01

    Astrophysical and cosmological observations do not require the dark matter particles to be absolutely stable. If they are indeed unstable, their decay into Standard Model particles might occur at a sufficiently large rate to allow the indirect detection of dark matter through an anomalous contribution to the high energy cosmic ray fluxes. We analyze the implications of the excess in the total electron plus positron flux and the positron fraction reported by the Fermi and PAMELA collaborations, respectively, for the scenario of decaying dark matter. We also discuss the constraints on this scenario from measurements of other cosmic ray species and the predictions for the diffuse gamma ray flux and the neutrino flux. In particular, we expect a sizable dipole-like anisotropy which may be observed in the near future by the Fermi-LAT.

  5. Gamma radiation associated to stellar formation in the galaxy (cosmic ray astronomy)

    International Nuclear Information System (INIS)

    Casse, Michel.

    1980-05-01

    The gamma ray sky revealed by the COS-B satellite is very peculiar: a few 'gamma ray stars' lying along the galactic plane emerge from a bright milky way. A possible interpretation of this sky is to invoke the existence of regions in which stars, cosmic rays and interstellar matter are very concentrated. A genetic link is established between clouds, stars and cosmic rays: the partial fragmentation of a cloud give birth to stars, the most massive stars accelerate cosmic rays through their supersonic stellar winds, cosmic ray interact in turn with the cloud material to copiously produce high energy gamma rays: a gamma ray source is born

  6. Long-term and transient time variation of cosmic ray fluxes detected in Argentina by CARPET cosmic ray detector

    Science.gov (United States)

    De Mendonça, R. R. S.; Raulin, J.-P.; Bertoni, F. C. P.; Echer, E.; Makhmutov, V. S.; Fernandez, G.

    2011-07-01

    We present results obtained at El Leoncito (CASLEO, San Juan, Argentina) with the CARPET charged particles detector installed in April 2006. The observed modulation of the cosmic ray flux is discussed as a function of its time variability and it is related to longer solar activity variations and to shorter variations during solar and geomagnetic transient activity. Short period (few minutes, few hours) cosmic ray modulation events are observed during rain time (precipitation) and significant variations of the atmospheric electric field. Complementary observations of the atmospheric electric field indicate that its time variations play an important role in the detected cosmic ray event.

  7. The Pierre Auger Cosmic Ray Observatory

    Czech Academy of Sciences Publication Activity Database

    Aab, A.; Abreu, P.; Aglietta, M.; Boháčová, Martina; Chudoba, Jiří; Ebr, Jan; Grygar, Jiří; Mandát, Dušan; Nečesal, Petr; Palatka, Miroslav; Pech, Miroslav; Prouza, Michael; Řídký, Jan; Schovánek, Petr; Trávníček, Petr; Vícha, Jakub

    2015-01-01

    Roč. 798, Oct (2015), s. 172-213 ISSN 0168-9002 R&D Projects: GA MŠk(CZ) LG13007; GA MŠk(CZ) 7AMB14AR005; GA ČR(CZ) GA14-17501S Institutional support: RVO:68378271 Keywords : Pierre Auger Observatory * high energy cosmic rays * hybrid observatory * water Cherenkov detectors * air fluorescence detectors Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.200, year: 2015

  8. Introduction to high energy cosmic ray physics

    International Nuclear Information System (INIS)

    Battistoni, G.; Grillo, A.F.

    1995-01-01

    After a few general qualitative considerations about the characteristics of primary cosmic rays arriving at the top of atmosphere, the fundamental concepts on their propagation and acceleration are discussed. The experimental situation, both from direct and indirect experiments, is presented, followed by a discussion on some concepts on hadronic interactions at high energy which are applied in a simplified and analytical model to the production of secondary particles in atmosphere

  9. Cosmic-ray cloud-chamber contributions to the discovery of the strange particles in the decade 1947-1957

    International Nuclear Information System (INIS)

    Rochester, G.D.

    1989-01-01

    This paper looks at the discovery and investigation of strange particles in the 1950s and points to the importance of two factors in achieving this, namely, penetrating-shower selection and counter control in cloud chambers. Experiments at Pic-du-Mide are detailed as is the Bagneres de Bigorre conference and concludes with some of the work done on charged strange particles. (UK)

  10. The Energetic Trans-Iron Cosmic-ray Experiment (ENTICE)

    Science.gov (United States)

    Binns, W. R.; Adams. J. H.; Barghouty, A. F.; Christian, E. R.; Cummings, A. C.; Hams, T.; Israel, M. H.; Labrador, A. W.; Leske, R. A.; Link, J. T.; hide

    2009-01-01

    The ENTICE experiment is one of two instruments that comprise the "Orbiting Astrophysical Spectrometer in Space (OASIS)", which is presently undergoing a NASA "Astrophysics Strategic Mission Concept Study". ENTICE is designed to make high precision measurements of the abundances of individual elements from neon through the actinides and, in addition, will search for possible superheavy nuclei in the galactic cosmic rays. The ENTICE instrument utilizes silicon detectors, aerogel and acrylic Cherenkov counters, and a scintillating optical fiber hodoscope to measure the charge and energy of these ultra-heavy nuclei for energies greater than 0.5 GeV/nucleon. It is a large instrument consisting of four modules with a total effective geometrical factor of approx.20 sq m sr. Measurements made in space for a period of three years with ENTICE will enable us to determine if cosmic rays include a component of recently synthesized transuranic elements (Pu-94 and Cm-96), to measure the age of that component, and to test the model of the OB association origin of galactic cosmic rays. Additionally, these observations will enable us to study how diffusive shock acceleration of cosmic rays operates differently on interstellar grains and gas. Keywords: cosmic rays Galaxy:abundances

  11. CERN explores link between cosmic rays and clouds

    CERN Multimedia

    2006-01-01

    "Scientists at CERN, the European Organisation for Nuclear Research, have started a new experiment to investigate the possible influence of galactic cosmic rays on the Earths clouds and climate. This is the first time that a high energy physics accelerator has been used for atmospheric and climate science." (1 page)

  12. Supernova remnants and the origin of cosmic rays

    NARCIS (Netherlands)

    Vink, J.

    2014-01-01

    Supernova remnants have long been considered to be the dominant sources of Galactic cosmic rays. For a long time the prime evidence consisted of radio synchrotron radiation from supernova remnants, indicating the presence of electrons with energies of several GeV. However, in order to explain the

  13. Search for tachyonomonopoles in cosmic rays

    International Nuclear Information System (INIS)

    Bartlett, D.F.; Nauenberg, U.

    1977-05-01

    Two of the most speculative particles are the magnetic monopole and the tachyon. One conjectures that these particles exist in cosmic rays as a combined ''tachyon monopole''. The fringing magnetic field of Fermilab's 15-foot bubble chamber is used to ''accelerate'' the tachyon to sufficiently high energy that it can emit visible Cherenkov radiation. This radiation is detected by 8 photomultiplier tubes mounted on the corners of a room-sized box which is suspended from the ceiling above the bubble chamber. Two small plastic scintillator counters placed inside the box differentiate between extensive air showers and tachyon monopoles. The detector was exposed to cosmic rays for 50 days. During that time we have not recorded any tachyon monopoles. The flux of such particles in cosmic rays cannot exceed 2.5 x 10 -15 cm -2 sec -1 if they follow the earth's magnetic field lines or 1.2 x 10 -12 cm -2 sec -1 if they do not. In either event this limit is at least 400 times lower than that inferred from a previous measurement. One did record counts from extensive air showers at a rate consistent with previous experiment. This rate was halved when the bubble chamber's magnetic field was turned off. This phenomenon was likely caused by focusing of the shower electrons in the fringing magnetic field of the bubble chamber

  14. Cosmic rays and Earth's climate

    DEFF Research Database (Denmark)

    Svensmark, Henrik

    2000-01-01

    During the last solar cycle the Earth's cloud cover underwent a modulation in phase with the cosmic ray flux. Assuming that there is a causal relationship between the two, it is expected and found that the Earth's temperature follows more closely decade variations in cosmic ray flux than other...... solar activity parameters. If the relationship is real the state of the Heliosphere affects the Earth's climate....

  15. Hard jet production in cosmic ray particle interactions at the energy of about 1000 TeV

    International Nuclear Information System (INIS)

    Buja, Z.; Gladysz, E.; Mikocki, S.; Szarska, M.; Zawiejski, L.

    1987-01-01

    Eight photon-hadron families with the energy of primary particles of about 1000 TeV detected in a X-ray emulsion chamber of Pamir Experiment have features which indicate the production of hard jets. Lateral distribution and the distribution of transverse momentum flow indicate the existence of two groups of particles. The average transverse momentum for particles in one group is more than 6 times larger then that for the other group. Azimuthal asymmetry is visible in the particle number and transverse momentum flow. Transverse energy E T for individual families oscillates between 26 and 120 GeV with an average value of 57 GeV. The experimental results were compared with Monte Carlo simulation in which QCD parton hard scattering mechanism in interactions of primary hadrons was assumed. An agreement can be reached if the fraction of jet production exceeded 60% and the transverse momenta of jets are not smaller than 40 GeV/c. 37 refs., 11 figs. (author)

  16. The History of Cosmic Ray Studies after Hess

    Energy Technology Data Exchange (ETDEWEB)

    Grupen, Claus, E-mail: grupen@physik.uni-siegen.de

    2013-06-15

    The discovery of cosmic rays by Victor Hess was confirmed with balloon flights at higher altitudes by Kolhörster. Soon the interest turned into questions about the nature of cosmic rays: gamma rays or particles? Subsequent investigations have established cosmic rays as the birthplace of elementary particle physics. The 1936 Nobel prize was shared between Victor Hess and Carl Anderson. Anderson discovered the positron in a cloud chamber. The positron was predicted by Dirac several years earlier. Many new results came now from studies with cloud chambers and nuclear emulsions. Anderson and Neddermeyer saw the muon, which for some time was considered to be a candidate for the Yukawa particle responsible for nuclear binding. Lattes, Powell, Occhialini and Muirhead clarified the situation by the discovery of the charged pions in cosmic rays. Rochester and Butler found V's, which turned out to be short-lived neutral kaons decaying into a pair of charged pions. Λ's, Σ's and Ξ's were found in cosmic rays using nuclear emulsions. After that period, accelerators and storage rings took over. The unexpected renaissance of cosmic rays started with the search for solar neutrinos and the observation of the supernova 1987A and other accelerators in the sky. With the observation of neutrino oscillations one began to look beyond the standard model of elementary particles. After 100 years of cosmic ray research we are again at the beginning of a new era, and cosmic rays may contribute to solve the many open questions, like dark matter and dark energy, by providing energies well beyond those of earth-bound accelerators.

  17. Are we making progress in finding the sources of the most energetic cosmic rays?

    International Nuclear Information System (INIS)

    Hillas, A. M.

    1999-01-01

    There is progress, in the sense that although the energies assigned to cosmic rays by air shower arrays may need reducing by about 20%, energy measurements are consistent at about this level, and several experiments now accord with a spectrum which astonishingly shows no GZK cut-off near 10 20 eV, greatly limiting the possible source regions. The simplest interpretation is that few cosmic rays above 10 19 eV come from hundreds of Mpc, contrary to expectation on geometrical grounds. Most of the arrival directions of showers above 4 x 10 19 eV show little correlation with the supergalaxy or with matter concentrations within 200 Mpc. The implications of the spectrum and the arrival directions are discussed. The most likely explanations of their unexpected features are either (a) that these cosmic rays come mainly from the decay of cosmological relic particles clustered in a large galactic halo (though not if photons really do form a large part of the decay spectrum), or (b) that local intergalactic magnetic fields are unexpectedly strong, and disguise the position of and enhance one extraordinary source within a few Mpc, or (c) most particles above 10 19 eV are very different from protons after all, and do not have a threshold for serious energy loss as low as 10 20 eV, or (d) that there is a conspiracy of matching fluxes, so that most cosmic rays above 10 19 eV are from widespread extragalactic sources, but a superimposed hard spectrum from decaying halo relic particles neatly reduces the magnitude of the GZK fall-off above 10 20 eV. Several close pairs of arrival directions may yet turn out to be accidental, but if not, explanations (a) and (b) fail. There are several diagnostic tests to be made by the well-placed first (Southern) Auger Project detector and the High-Resolution Fly's Eye detector

  18. Particle production in very-high-energy cosmic-ray emulsion chamber events: Usual and unusual events

    International Nuclear Information System (INIS)

    Costa, C.G.S.; Halzen, F.; Salles, C.

    1995-01-01

    We show that a simple scaling model of very forward particle production, consistent with accelerator and air shower data, can describe the overall features of the very-high-energy interactions recorded with emulsion chambers. The rapidity and transverse momentum distribution of the secondaries are quantitatively reproduced. This is somewhat surprising after numerous claims that the same data implied large scaling violations or new dynamics. Interestingly, we cannot describe some of the Centauro events, suggesting that these events are anomalous independently of their well-advertised unusual features such as the absence of neutral secondaries

  19. The origin of very high cosmic rays

    International Nuclear Information System (INIS)

    Colgate, S.A.

    1975-01-01

    There are now two arguments that indicate that the whole cosmic ray spectrum is created in every galaxy, primarily Sc galaxies, and furthermore, that the source(s) should be occuring randomly such as supernova approximately = 1 per 50 years. The canonical source must produce a flatter spectrum by E +1 for E > 10 15 eV so that galactic leakage approximately E**-1 gives the observed slope, E 18 eV. For E > 3 x 10 18 eV all galaxies contribute to the extragalactic flux which equals approximately the galactic flux. Anisotropy occurs because of the statistical probability that several sources (supernovae) occur in this galaxy in the time and position such as to give rise to a flux greater than the extragalactic flux. (orig./BJ) [de

  20. Long-term variations of cosmic ray intensity

    International Nuclear Information System (INIS)

    Dergachev, V.A.; Kocharov, G.E.; Ostryakov, V.M.

    1982-01-01

    At the present time we know only one possibility to reconstruct the Cosmic Ray intensity in the past. This possibility is connected with the measurements of radiocarbon abundance in the dendrochronologically dated wood samples. As the experiments carried out with the help of spacecrafts, balloons and ground apparatus show the Galactic Cosmic Ray flux essentially varies on a short time scales. The variations are caused by different astrophysical and geophysical phenomena. 14 C isotope allows us to investigate these reasons on a more long time interval in comparison with direct observational possibilities

  1. 14. European cosmic ray symposium. Symposium program and abstracts

    International Nuclear Information System (INIS)

    1994-08-01

    The abstracts of the 14. European Cosmic Ray Symposium are presented. The papers cover a large variety of topics in cosmic ray physics, both from the theoretical and the experimental point of view. Sun physics, and the effects on the inner heliosphere, the composition, and the properties of the primary and secondary cosmic radiation, galactic acceleration and the results of accelerator physics relevant to cosmic radiation physics, and the description and the results of large detector systems are presented. 63 items are indexed for INIS database. (K.A.)

  2. Measurement of H, He, C and O Cosmic ray primaries preliminary results from the CREAM II experiment

    CERN Document Server

    Mognet, Samuel

    The direct measurement of the energy spectrum and composition of the incoming cosmic-ray flux at multi-TeV energies is of great interest. A feature located somewhere between 1000-10,000 TeV in the all-particle spectrum, referred to as the ‘knee’ characterized by a steepening of the power-law flux, has been observed by ground-based detectors for many years. It is believed to be related to an upper limit or change in efficiency of the Galactic accelerators of cosmic rays and/or properties of the propagation of cosmic rays in the Galaxy. Presented here is a preliminary analysis of the flux of primary H, He, C and O cosmic-ray species measured using the CREAM II instrument. This analysis is conducted using the Penn State-built Timing Charge Detector, distinct from other charge detectors used in alternative published CREAM II results. The second Antarctic flight of the CREAM instrument had a ∼ 28 day flight in the 2005-2006 Antarctic flight season. The instrument was launched on December 16th 2005 from Willi...

  3. Theoretical galactic cosmic ray electron spectrum obtained for sources of varying geometry; Spectre theorique des electrons du rayonnement cosmique dans la galaxie obtenu pour des sources a geometrie variable

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, M E [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    Jokipii and Meyer have recently obtained an electron density energy spectrum of the cosmic rays, originating in the Galaxy, using integral solutions of the steady state transfer equations, by considering a circular cylindric galactic disc as source and approximating the resulting fourth order integral. In this report, we present general results, obtained by using an arbitrary circular cylindric source, without restricting ourselves to the galactic disc. The integrals are treated exactly. The conclusions of Jokipii and Meyer form special cases of these results. We also obtain an exponential energy variation which, at the moment, is not observed experimentally. The second part of this work deals with more complicated, but perhaps more realistic models of elliptic cylindric and ellipsoidal galactic disc sources. One may also note that a very large source concentrated in a very small region gives a spectrum not unlike that for a small source distributed throughout a large volume. Finally, it may be remarked that the model adopted is much less restrictive than the artificial conception of 'leakage time' followed by other workers. (author) [French] Jokipii et Meyer ont dernierement obtenu un spectre d'energie pour les electrons galactiques dans le rayonnement cosmique, en utilisant les solutions des equations de transfert, a l'etat stationnaire, ces dernieres etant sous forme d'integrales, en prenant une source completement diffusee dans le disque galactique, celui-ci etant hypothetiquement choisi comme circulaire et cylindrique et en faisant une approximation sur l'integrale du quatrieme degre. Dans ce rapport, nous presentons des resultats generaux obtenus en faisant appel a une source, diffusee dans un cylindre circulaire, arbitrairement choisi, c'est-a-dire sans nous restreindre au disque galactique comme source. Les integrales sont traitees d'une maniere exacte. Les conclusions de Jokipii et Meyer constituent des cas speciaux des resultats precedents. Nous obtenons

  4. Calculation of cosmic ray induced single event upsets: Program CRUP (Cosmic Ray Upset Program)

    Science.gov (United States)

    Shapiro, P.

    1983-09-01

    This report documents PROGRAM CRUP, COSMIC RAY UPSET PROGRAM. The computer program calculates cosmic ray induced single-event error rates in microelectronic circuits exposed to several representative cosmic-ray environments.

  5. Experimental Investigation of Aerosols Produced by Cosmic Rays

    DEFF Research Database (Denmark)

    Pedersen, Jens Olaf Pepke; Enghoff, Martin Andreas Bødker; Svensmark, Henrik

    an experiment in order to investigate the underlying microphysical processes. The results of this experiment will help to understand whether ionisation from cosmic rays, and by implication the related processes in the universe, has a direct influence on Earth’s atmosphere and climate. Since any physical...... mechanism linking cosmic rays to clouds and climate is currently speculative, there have been various suggestions of the role atmospheric ions may play; these involve any one of a number of processes from the nucleation of aerosols up to the collection processes of cloud droplets.We have chosen to start our......Satellite observations have shown that the Earth’s cloud cover is strongly correlated with the galactic cosmic ray flux. While this correlation is indicative of a possible physical connection, there is currently no confirmation that a physical mechanism exists. We are therefore setting up...

  6. Cosmic rays,Climate and the CERN CLOUD Experiment

    CERN Multimedia

    CERN. Geneva

    2011-01-01

    For more than two centuries, scientists have been puzzled by observations of solar-climate variability yet the lack of any established physical mechanism. Some recent observations, although disputed, suggest that clouds may be influenced by cosmic rays, which are modulated by the solar wind. The CLOUD experiment aims to settle the question of whether or not cosmic rays have a climatically-significant effect on clouds by carrying out a series of carefully-controlled measurements in a large cloud chamber exposed to a beam from the CERN PS. This talk will present the scientific motivation for CLOUD and the first results, which have recently been published in Nature (Kirkby et al. (2011). Role of sulphuric acid, ammonia and galactic cosmic rays in atmospheric aerosol nucleation. Nature 476, 429-433).

  7. Bubbles, superbubbles and their impact on cosmic ray transport

    Energy Technology Data Exchange (ETDEWEB)

    Weinreuter, Matthias; Gebauer, Iris; Boer, Wim de; Neumann, Alexander [KIT, Karlsruhe (Germany)

    2016-07-01

    The Fermi-LAT data on diffuse gamma rays show variations in the gamma ray intensity, which are linked to either variations in the gas density or variations in the cosmic ray density. Such small scale variations are not modeled in current state-of-the-art models for galactic cosmic ray propagation. Inhomogeneities in the interstellar material can be formed by cavities like the so-called Local Bubble, an underdense region surrounding our Sun, which was created by several supernova explosions in the past. We show that the Local Bubble can have a strong impact on the cosmic ray energy spectra and density. In particular, it enhances cosmic ray scattering in the surrounding molecular cloud complexes and can significantly distort the cosmic ray arrival directions. We briefly discuss the consequences for pulsar searches in energetic positrons and electrons. By making simple assumptions on the level of inhomogeneity in the interstellar medium we investigate if the observed variations in the diffuse gamma ray emission can indeed be explained by cavities similar to the Local Bubble.

  8. The Hisparc cosmic ray experiment : data acquisition and reconstruction of shower direction

    NARCIS (Netherlands)

    Fokkema, D.; Fokkema, D.

    2012-01-01

    The field of cosmic ray physics is a century old and an exciting area of research. When cosmic ray particles enter our atmosphere they collide with air molecules creating new high-energy particles. These particles participate in further collisions and the entire process is known as an air shower.

  9. Cosmic ray-dark matter scattering: a new signature of (asymmetric) dark matter in the gamma ray sky

    International Nuclear Information System (INIS)

    Profumo, Stefano; Ubaldi, Lorenzo

    2011-01-01

    We consider the process of scattering of Galactic cosmic-ray electrons and protons off of dark matter with the radiation of a final-state photon. This process provides a novel way to search for Galactic dark matter with gamma rays. We argue that for a generic weakly interacting massive particle, barring effects such as co-annihilation or a velocity-dependent cross section, the gamma-ray emission from cosmic-ray scattering off of dark matter is typically smaller than that from dark matter pair-annihilation. However, if dark matter particles cannot pair-annihilate, as is the case for example in asymmetric dark matter scenarios, cosmic-ray scattering with final state photon emission provides a unique window to detect a signal from dark matter with gamma rays. We estimate the expected flux level and its spectral features for a generic supersymmetric setup, and we also discuss dipolar and luminous dark matter. We show that in some cases the gamma-ray emission might be large enough to be detectable with the Fermi Large Area Telescope

  10. Cosmic rays, clouds, and climate

    DEFF Research Database (Denmark)

    Marsh, N.; Svensmark, Henrik

    2000-01-01

    cloud radiative properties. Thus, a moderate influence on atmospheric aerosol distributions from cosmic ray ionisation would have a strong influence on the Earth's radiation budget. Historical evidence over the past 1000 years indicates that changes in climate have occurred in accord with variability......A correlation between a global average of low cloud cover and the flux of cosmic rays incident in the atmosphere has been observed during the last solar cycle. The ionising potential of Earth bound cosmic rays are modulated by the state of the heliosphere, while clouds play an important role...... in the Earth's radiation budget through trapping outgoing radiation and reflecting incoming radiation. If a physical link between these two features can be established, it would provide a mechanism linking solar activity and Earth's climate. Recent satellite observations have further revealed a correlation...

  11. Measurement of cosmic-ray muons with the Distributed Electronic Cosmic-ray Observatory, a network of smartphones

    International Nuclear Information System (INIS)

    Vandenbroucke, J.; Bravo, S.; Karn, P.; Meehan, M.; Plewa, M.; Schultz, D.; Tosi, D.; BenZvi, S.; Jensen, K.; Peacock, J.; Ruggles, T.; Santander, M.; Simons, A.L.

    2016-01-01

    Solid-state camera image sensors can be used to detect ionizing radiation in addition to optical photons. We describe the Distributed Electronic Cosmic-ray Observatory (DECO), an app and associated public database that enables a network of consumer devices to detect cosmic rays and other ionizing radiation. In addition to terrestrial background radiation, cosmic-ray muon candidate events are detected as long, straight tracks passing through multiple pixels. The distribution of track lengths can be related to the thickness of the active (depleted) region of the camera image sensor through the known angular distribution of muons at sea level. We use a sample of candidate muon events detected by DECO to measure the thickness of the depletion region of the camera image sensor in a particular consumer smartphone model, the HTC Wildfire S. The track length distribution is fit better by a cosmic-ray muon angular distribution than an isotropic distribution, demonstrating that DECO can detect and identify cosmic-ray muons despite a background of other particle detections. Using the cosmic-ray distribution, we measure the depletion thickness to be 26.3 ± 1.4 μm. With additional data, the same method can be applied to additional models of image sensor. Once measured, the thickness can be used to convert track length to incident polar angle on a per-event basis. Combined with a determination of the incident azimuthal angle directly from the track orientation in the sensor plane, this enables direction reconstruction of individual cosmic-ray events using a single consumer device. The results simultaneously validate the use of cell phone camera image sensors as cosmic-ray muon detectors and provide a measurement of a parameter of camera image sensor performance which is not otherwise publicly available

  12. Study of cosmic rays reveals secrets of solar-terrestrial science

    Science.gov (United States)

    Jokipii, J. R.

    For many years cosmic rays provided the most important source of energetic particles for studies of subatomic physics. Today, cosmic rays are being studied as a natural phenomenon that can tell us much about both the Earth's environment in space and distant astrophysical processes. Cosmic rays are naturally occurring energetic particles—mainly ions—with kinetic energies extending from just above thermal energies to more than 1020 electron volts (eV). They constantly bombard the Earth from all directions, with more than 1018 particles having energies >1 MeV striking the top of the Earth's atmosphere each second. Figure 1 illustrates the continuous cosmic ray energy spectrum.

  13. VI School on Cosmic Rays and Astrophysics

    International Nuclear Information System (INIS)

    2017-01-01

    VI School on Cosmic Rays and Astrophysics 17-25 November 2015, Chiapas, Mexico The VI School on Cosmic Rays and Astrophysics was held at the MCTP, at the Autonomous University of Chiapas (UNACH), Tuxtla Gutiérrez, Chiapas, Mexico thanks to the Science for Development ICTP-UNACH-UNESCO Regional Seminar, 17-25 November 2015 (http://mctp.mx/e-VI-School-on-Cosmic-Rays-and-Astrophysics.html). The School series started in La Paz, Bolivia in 2004 and it has been, since then, hosted by several Latin American countires: 1.- La Paz, Bolivia (August, 2004), 2.- Puebla, Mexico (September, 2006), 3.- Arequipa, Peru (September, 2008), 4.- Santo André, Brazil (September, 2010), 5.- La Paz, Bolivia (August, 2012). It aims to promote Cosmic Ray (CR) Physics and Astrophysics in the Latin American community and to provide a general overview of theoretical and experimental issues on these topics. It is directed to undergraduates, postgraduates and active researchers in the field. The lectures introduce fundamental Cosmic Ray Physics and Astrophysics with a review of standards of the field. It is expected the school continues happening during the next years following a tradition. In this edition, the list of seminars included topics such as experimental techniques of CR detection, development of CR showers and hadronic interactions, composition and energy spectrum of primary CR, Gamma-Ray Bursts (GRBs), neutrino Astrophysics, spacecraft detectors, simulations, solar modulation, and the current state of development and results of several astroparticle physics experiments such as The Pierre Auger Observatory in Argentina, HAWC in Mexico, KASCADE and KASCADE Grande, HESS, IceCube, JEM-EUSO, Fermi-LAT, and others. This time the school has been complemented with the ICTP-UNACH-UNESCO Seminar of theory on Particle and Astroparticle Physics. The organization was done by MCTP, the Mesoamerican Centre for Theoretical Physics. The school had 46 participants, 30 students from Honduras, Brazil

  14. Anomalous Transport of Cosmic Rays in a Nonlinear Diffusion Model

    Energy Technology Data Exchange (ETDEWEB)

    Litvinenko, Yuri E. [Department of Mathematics, University of Waikato, P. B. 3105, Hamilton 3240 (New Zealand); Fichtner, Horst; Walter, Dominik [Institut für Theoretische Physik IV, Ruhr-Universität Bochum, Universitätsstrasse 150, D-44780 Bochum (Germany)

    2017-05-20

    We investigate analytically and numerically the transport of cosmic rays following their escape from a shock or another localized acceleration site. Observed cosmic-ray distributions in the vicinity of heliospheric and astrophysical shocks imply that anomalous, superdiffusive transport plays a role in the evolution of the energetic particles. Several authors have quantitatively described the anomalous diffusion scalings, implied by the data, by solutions of a formal transport equation with fractional derivatives. Yet the physical basis of the fractional diffusion model remains uncertain. We explore an alternative model of the cosmic-ray transport: a nonlinear diffusion equation that follows from a self-consistent treatment of the resonantly interacting cosmic-ray particles and their self-generated turbulence. The nonlinear model naturally leads to superdiffusive scalings. In the presence of convection, the model yields a power-law dependence of the particle density on the distance upstream of the shock. Although the results do not refute the use of a fractional advection–diffusion equation, they indicate a viable alternative to explain the anomalous diffusion scalings of cosmic-ray particles.

  15. World's largest air shower array now on track of super-high-energy cosmic-rays Pierre Auger Observatory seeks source of highest-energy extraterrestrial particles

    CERN Multimedia

    2003-01-01

    "With the completion of its hundredth surface detector, the Pierre Auger Observatory, under construction in Argentina, this week became the largest cosmic-ray air shower array in the world. Managed by scientists at the Department of Energy's Fermi National Accelerator Laboratory, the Pierre Auger project so far encompasses a 70-square-mile array of detectors that are tracking the most violent-and perhaps most puzzling- processes in the entire universe" (1 page).

  16. Cosmic-ray sum rules

    International Nuclear Information System (INIS)

    Frandsen, Mads T.; Masina, Isabella; Sannino, Francesco

    2011-01-01

    We introduce new sum rules allowing to determine universal properties of the unknown component of the cosmic rays; we show how they can be used to predict the positron fraction at energies not yet explored by current experiments, and to constrain specific models.

  17. Cosmic ray driven instability

    International Nuclear Information System (INIS)

    Dorfi, E.A.; Drury, L.O.

    1985-01-01

    The interaction between energetic charged particles and thermal plasma, which forms the basis of diffusive shock acceleration, leads also to interesting dynamical phenomena. For a compressional mode propagating in a system with homoeneous energetic particle pressure it is well known that friction with the energetic particles leads to damping. The linear theory of this effect has been analyzed in detail by Ptuskin. Not so obvious is that a non-uniform energetic particle pressure can in addition amplify compressional disturbances. If the pressure gradient is sufficiently steep this growth can dominate the frictional damping and lead to an instability. It is important to not that this effect results from the collective nature of the interaction between the energetic particles and the gas and is not connected with the Parker instability, nor with the resonant amplification of Alfven waves

  18. Cosmic ray access at polar heliographic latitudes

    International Nuclear Information System (INIS)

    Voelk, H.J.

    1976-01-01

    Based on a modified WKB analysis of the interplanetary irregularity spectra, a discussion of the radial dependence of the radial cosmic ray diffusion coefficient at polar heliographic latitudes is presented. At l-AU radial distance the parameters are taken to equal those observed in the ecliptic. In the sense of a present best estimate it is argued that relativistic nuclei should have significantly easier access to 1 AU at the pole than in the ecliptic. The reverse may very well be true for the direct access of very low rigidity particles

  19. Highest energy cosmic rays

    International Nuclear Information System (INIS)

    Nikolskij, S.

    1984-01-01

    Primary particles of cosmic radiation with highest energies cannot in view of their low intensity be recorded directly but for this purpose the phenomenon is used that these particles interact with nuclei in the atmosphere and give rise to what are known as extensive air showers. It was found that 40% of primary particles with an energy of 10 15 to 10 16 eV consist of protons, 12 to 15% of helium nuclei, 15% of iron nuclei, the rest of nuclei of other elements. Radiation intensity with an energy of 10 18 to 10 19 eV depends on the direction of incoming particles. Maximum intensity is in the direction of the centre of the nearest clustre of galaxies, minimal in the direction of the central area of our galaxy. (Ha)

  20. Cosmic rays and terrestrial life: A brief review

    Science.gov (United States)

    Atri, Dimitra; Melott, Adrian L.

    2014-01-01

    “The investigation into the possible effects of cosmic rays on living organisms will also offer great interest.” - Victor F. Hess, Nobel Lecture, December 12, 1936 High-energy radiation bursts are commonplace in our Universe. From nearby solar flares to distant gamma ray bursts, a variety of physical processes accelerate charged particles to a wide range of energies, which subsequently reach the Earth. Such particles contribute to a number of physical processes occurring in the Earth system. A large fraction of the energy of charged particles gets deposited in the atmosphere, ionizing it, causing changes in its chemistry and affecting the global electric circuit. Remaining secondary particles contribute to the background dose of cosmic rays on the surface and parts of the subsurface region. Life has evolved over the past ∼3 billion years in presence of this background radiation, which itself has varied considerably during the period [1-3]. As demonstrated by the Miller-Urey experiment, lightning plays a very important role in the formation of complex organic molecules, which are the building blocks of more complex structures forming life. There is growing evidence of increase in the lightning rate with increasing flux of charged particles. Is there a connection between enhanced rate of cosmic rays and the origin of life? Cosmic ray secondaries are also known to damage DNA and cause mutations, leading to cancer and other diseases. It is now possible to compute radiation doses from secondary particles, in particular muons and neutrons. Have the variations in cosmic ray flux affected the evolution of life on earth? We describe the mechanisms of cosmic rays affecting terrestrial life and review the potential implications of the variation of high-energy astrophysical radiation on the history of life on earth.

  1. Cosmic-ray modulation: an ab initio approach

    Energy Technology Data Exchange (ETDEWEB)

    Engelbrecht, N.E.; Burger, R.A., E-mail: 12580996@nwu.ac.za [Center for Space Research, North-West University, Potchefstroom (South Africa)

    2014-07-01

    A better understanding of cosmic-ray modulation in the heliosphere can only be gained through a proper understanding of the effects of turbulence on the diffusion and drift of cosmic rays. We present an ab initio model for cosmic-ray modulation, incorporating for the first time the results yielded by a two-component turbulence transport model. This model is solved for periods of minimum solar activity, utilizing boundary values chosen so that model results are in fair to good agreement with spacecraft observations of turbulence quantities, not only in the solar ecliptic plane but also along the out-of-ecliptic trajectory of the Ulysses spacecraft. These results are employed as inputs for modelled slab and 2D turbulence energy spectra. The latter spectrum is chosen based on physical considerations, with a drop-off at the very lowest wavenumbers commencing at the 2D outerscale. There currently exist no models or observations for this quantity, and it is the only free parameter in this study. The modelled turbulence spectra are used as inputs for parallel mean free path expressions based on those derived from quasi-linear theory and perpendicular mean free paths from extended nonlinear guiding center theory. Furthermore, the effects of turbulence on cosmic-ray drifts are modelled in a self-consistent way, employing a recently developed model for drift along the wavy current sheet. The resulting diffusion coefficients and drift expressions are applied to the study of galactic cosmic-ray protons and antiprotons using a three dimensional, steady-state cosmic-ray modulation code, and sample solutions in fair agreement with multiple spacecraft observations are presented. (author)

  2. Cosmic-ray modulation: an ab initio approach

    International Nuclear Information System (INIS)

    Engelbrecht, N.E.; Burger, R.A.

    2014-01-01

    A better understanding of cosmic-ray modulation in the heliosphere can only be gained through a proper understanding of the effects of turbulence on the diffusion and drift of cosmic rays. We present an ab initio model for cosmic-ray modulation, incorporating for the first time the results yielded by a two-component turbulence transport model. This model is solved for periods of minimum solar activity, utilizing boundary values chosen so that model results are in fair to good agreement with spacecraft observations of turbulence quantities, not only in the solar ecliptic plane but also along the out-of-ecliptic trajectory of the Ulysses spacecraft. These results are employed as inputs for modelled slab and 2D turbulence energy spectra. The latter spectrum is chosen based on physical considerations, with a drop-off at the very lowest wavenumbers commencing at the 2D outerscale. There currently exist no models or observations for this quantity, and it is the only free parameter in this study. The modelled turbulence spectra are used as inputs for parallel mean free path expressions based on those derived from quasi-linear theory and perpendicular mean free paths from extended nonlinear guiding center theory. Furthermore, the effects of turbulence on cosmic-ray drifts are modelled in a self-consistent way, employing a recently developed model for drift along the wavy current sheet. The resulting diffusion coefficients and drift expressions are applied to the study of galactic cosmic-ray protons and antiprotons using a three dimensional, steady-state cosmic-ray modulation code, and sample solutions in fair agreement with multiple spacecraft observations are presented. (author)

  3. On the Origin of Ultra High Energy Cosmic Rays II

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, T K; Colgate, S; Li, H; Bulmer, R H; Pino, J

    2011-03-08

    We show that accretion disks around Active Galactic Nuclei (AGNs) could account for the enormous power in observed ultra high energy cosmic rays {approx}10{sup 20} eV (UHEs). In our model, cosmic rays are produced by quasi-steady acceleration of ions in magnetic structures previously proposed to explain jets around Active Galactic Nuclei with supermassive black holes. Steady acceleration requires that an AGN accretion disk act as a dynamo, which we show to follow from a modified Standard Model in which the magnetic torque of the dynamo replaces viscosity as the dominant mechanism accounting for angular momentum conservation during accretion. A black hole of mass M{sub BH} produces a steady dynamo voltage V {proportional_to} {radical}M{sub BH} giving V {approx} 10{sup 20} volts for M{sub BH} {approx} 10{sup 8} solar masses. The voltage V reappears as an inductive electric field at the advancing nose of a dynamo-driven jet, where plasma instability inherent in collisionless runaway acceleration allows ions to be steadily accelerated to energies {approx} V, finally ejected as cosmic rays. Transient events can produce much higher energies. The predicted disk radiation is similar to the Standard Model. Unique predictions concern the remarkable collimation of jets and emissions from the jet/radiolobe structure. Given MBH and the accretion rate, the model makes 7 predictions roughly consistent with data: (1) the jet length; (2) the jet radius; (3) the steady-state cosmic ray energy spectrum; (4) the maximum energy in this spectrum; (5) the UHE cosmic ray intensity on Earth; (6) electron synchrotron wavelengths; and (7) the power in synchrotron radiation. These qualitative successes motivate new computer simulations, experiments and data analysis to provide a quantitative verification of the model.

  4. Pulsars and cosmic rays in the dense supernova shells

    International Nuclear Information System (INIS)

    Berezinsky, V.S.; Prilutsky, O.F.

    1977-01-01

    Cosmic rays (c.r.) injected by a young pulsar in the dense supernova shell are considered. The maintenance of the Galactic c.r. pool by pulsar production is shown to have a difficulty: adiabatic energy losses of c.r. in the expanding shell demand a high initial c.r. luminosity of pulsar, which results in too high flux of γ-radiation produced through π 0 -decays (in excess over diffuse γ-ray background). (author)

  5. Cosmic-ray phenomenology and data analysis with the CREAM experiment

    International Nuclear Information System (INIS)

    Coste, B.

    2012-01-01

    The sources of Galactic cosmic-ray (GCR) nuclei are still poorly identified. This is partly due to the diffusive propagation (in turbulent magnetic fields) that erases all directional information about the measured fluxes. The species that are predominantly created and accelerated in the sources are denoted 'primary species'. Those mostly created by spallation of heavier primary species are denoted 'secondary species'. While primary fluxes give access to the source parameters, secondary- to-primary ratios trace propagation processes. Key quantities for such studies are the fragmentation cross sections on the interstellar gas and the measured fluxes and ratios. In the first part of this thesis, we provide new constraints on the Galactic propagation parameters from the quartet of elements ( 1 H, 2 H, 3 He, 4 He), relying on a new estimate of their cross sections and a detailed statistical analysis. The derived constraints are competitive with those obtained from the standard B/C ratio analysis. The results are however limited by the precision of current measurements and motivate the development of new experiments. The second part of this thesis is dedicated to the analysis of cosmic-ray fluxes measured with the CREAM balloon-borne experiment. We present the particle identification in the detector, the estimation of efficiencies for each sub-detector, the energy reconstruction, and the atmospheric correction. Applied to the 3. flight data (CREAM-III), we provide new data points for the boron, carbon, nitrogen and oxygen elements above 100 GeV/n. (author)

  6. Characterising CCDs with cosmic rays

    International Nuclear Information System (INIS)

    Fisher-Levine, M.; Nomerotski, A.

    2015-01-01

    The properties of cosmic ray muons make them a useful probe for measuring the properties of thick, fully depleted CCD sensors. The known energy deposition per unit length allows measurement of the gain of the sensor's amplifiers, whilst the straightness of the tracks allows for a crude assessment of the static lateral electric fields at the sensor's edges. The small volume in which the muons deposit their energy allows measurement of the contribution to the PSF from the diffusion of charge as it drifts across the sensor. In this work we present a validation of the cosmic ray gain measurement technique by comparing with radioisotope gain measurments, and calculate the charge diffusion coefficient for prototype LSST sensors

  7. Cosmic-ray neutron simulations and measurements in Taiwan

    International Nuclear Information System (INIS)

    Chen, Wei-Lin; Jiang, Shiang-Huei; Sheu, Rong-Jiun

    2014-01-01

    This study used simulations of galactic cosmic ray in the atmosphere to investigate the neutron background environment in Taiwan, emphasising its altitude dependence and spectrum variation near interfaces. The calculated results were analysed and compared with two measurements. The first measurement was a mobile neutron survey from sea level up to 3275 m in altitude conducted using a car-mounted high-sensitivity neutron detector. The second was a previous measured result focusing on the changes in neutron spectra near air/ground and air/water interfaces. The attenuation length of cosmic-ray neutrons in the lower atmosphere was estimated to be 163 g cm -2 in Taiwan. Cosmic-ray neutron spectra vary with altitude and especially near interfaces. The determined spectra near the air/ground and air/water interfaces agree well with measurements for neutrons below 10 MeV. However, the high-energy portion of spectra was observed to be much higher than our previous estimation. Because high-energy neutrons contribute substantially to a dose evaluation, revising the annual sea-level effective dose from cosmic-ray neutrons at ground level in Taiwan to 35 μSv, which corresponds to a neutron flux of 5.30 x 10 -3 n cm -2 s -1 , was suggested. The cosmic-ray neutron background in Taiwan was studied using the FLUKA simulations and field measurements. A new measurement was performed using a car-mounted high-efficiency neutron detector, re-coding real-time neutron counting rates from sea level up to 3275 m. The attenuation of cosmic-ray neutrons in the lower atmosphere exhibited an effective attenuation length of 163 g cm -2 . The calculated neutron counting rates over predicted the measurements by ∼32 %, which leaded to a correction factor for the FLUKA-calculated cosmic-ray neutrons in the lower atmosphere in Taiwan. In addition, a previous measurement regarding neutron spectrum variation near the air/ground and air/water interfaces was re-evaluated. The results showed that the

  8. CrossRef Antiproton Flux, Antiproton-to-Proton Flux Ratio, and Properties of Elementary Particle Fluxes in Primary Cosmic Rays Measured with the Alpha Magnetic Spectrometer on the International Space Station

    CERN Document Server

    Aguilar, M; Alpat, B; Ambrosi, G; Arruda, L; Attig, N; Aupetit, S; Azzarello, P; Bachlechner, A; Barao, F; Barrau, A; Barrin, L; Bartoloni, A; Basara, L; Başeǧmez-du Pree, S; Battarbee, M; Battiston, R; Bazo, J; Becker, U; Behlmann, M; Beischer, B; Berdugo, J; Bertucci, B; Bindi, V; Boella, G; de Boer, W; Bollweg, K; Bonnivard, V; Borgia, B; Boschini, M  J; Bourquin, M; Bueno, E  F; Burger, J; Cadoux, F; Cai, X  D; Capell, M; Caroff, S; Casaus, J; Castellini, G; Cernuda, I; Cervelli, F; Chae, M  J; Chang, Y  H; Chen, A  I; Chen, G  M; Chen, H  S; Cheng, L; Chou, H  Y; Choumilov, E; Choutko, V; Chung, C  H; Clark, C; Clavero, R; Coignet, G; Consolandi, C; Contin, A; Corti, C; Coste, B; Creus, W; Crispoltoni, M; Cui, Z; Dai, Y  M; Delgado, C; Della Torre, S; Demirköz, M  B; Derome, L; Di Falco, S; Dimiccoli, F; Díaz, C; von Doetinchem, P; Dong, F; Donnini, F; Duranti, M; D'Urso, D; Egorov, A; Eline, A; Eronen, T; Feng, J; Fiandrini, E; Finch, E; Fisher, P; Formato, V; Galaktionov, Y; Gallucci, G; García, B; García-López, R  J; Gargiulo, C; Gast, H; Gebauer, I; Gervasi, M; Ghelfi, A; Giovacchini, F; Goglov, P; Gómez-Coral, D  M; Gong, J; Goy, C; Grabski, V; Grandi, D; Graziani, M; Guerri, I; Guo, K  H; Habiby, M; Haino, S; Han, K  C; He, Z  H; Heil, M; Hoffman, J; Hsieh, T  H; Huang, H; Huang, Z  C; Huh, C; Incagli, M; Ionica, M; Jang, W  Y; Jinchi, H; Kang, S  C; Kanishev, K; Kim, G  N; Kim, K  S; Kirn, Th; Konak, C; Kounina, O; Kounine, A; Koutsenko, V; Krafczyk, M  S; La Vacca, G; Laudi, E; Laurenti, G; Lazzizzera, I; Lebedev, A; Lee, H  T; Lee, S  C; Leluc, C; Li, H  S; Li, J  Q; Li, Q; Li, T  X; Li, W; Li, Z  H; Li, Z  Y; Lim, S; Lin, C  H; Lipari, P; Lippert, T; Liu, D; Liu, Hu; Lu, S  Q; Lu, Y  S; Luebelsmeyer, K; Luo, F; Luo, J  Z; Lv, S  S; Majka, R; Mañá, C; Marín, J; Martin, T; Martínez, G; Masi, N; Maurin, D; Menchaca-Rocha, A; Meng, Q; Mo, D  C; Morescalchi, L; Mott, P; Nelson, T; Ni, J  Q; Nikonov, N; Nozzoli, F; Nunes, P; Oliva, A; Orcinha, M; Palmonari, F; Palomares, C; Paniccia, M; Pauluzzi, M; Pensotti, S; Pereira, R; Picot-Clemente, N; Pilo, F; Pizzolotto, C; Plyaskin, V; Pohl, M; Poireau, V; Putze, A; Quadrani, L; Qi, X  M; Qin, X; Qu, Z  Y; Räihä, T; Rancoita, P  G; Rapin, D; Ricol, J  S; Rodríguez, I; Rosier-Lees, S; Rozhkov, A; Rozza, D; Sagdeev, R; Sandweiss, J; Saouter, P; Schael, S; Schmidt, S  M; Schulz von Dratzig, A; Schwering, G; Seo, E  S; Shan, B  S; Shi, J  Y; Siedenburg, T; Son, D; Song, J  W; Sun, W  H; Tacconi, M; Tang, X  W; Tang, Z  C; Tao, L; Tescaro, D; Ting, Samuel C  C; Ting, S  M; Tomassetti, N; Torsti, J; Türkoğlu, C; Urban, T; Vagelli, V; Valente, E; Vannini, C; Valtonen, E; Vázquez Acosta, M; Vecchi, M; Velasco, M; Vialle, J  P; Vitale, V; Vitillo, S; Wang, L  Q; Wang, N  H; Wang, Q  L; Wang, X; Wang, X  Q; Wang, Z  X; Wei, C  C; Weng, Z  L; Whitman, K; Wienkenhöver, J; Willenbrock, M; Wu, H; Wu, X; Xia, X; Xiong, R  Q; Xu, W; Yan, Q; Yang, J; Yang, M; Yang, Y; Yi, H; Yu, Y  J; Yu, Z  Q; Zeissler, S; Zhang, C; Zhang, J; Zhang, J  H; Zhang, S  D; Zhang, S  W; Zhang, Z; Zheng, Z  M; Zhu, Z  Q; Zhuang, H  L; Zhukov, V; Zichichi, A; Zimmermann, N; Zuccon, P

    2016-01-01

    A precision measurement by AMS of the antiproton flux and the antiproton-to-proton flux ratio in primary cosmic rays in the absolute rigidity range from 1 to 450 GV is presented based on 3.49×105 antiproton events and 2.42×109 proton events. The fluxes and flux ratios of charged elementary particles in cosmic rays are also presented. In the absolute rigidity range ∼60 to ∼500  GV, the antiproton p¯, proton p, and positron e+ fluxes are found to have nearly identical rigidity dependence and the electron e− flux exhibits a different rigidity dependence. Below 60 GV, the (p¯/p), (p¯/e+), and (p/e+) flux ratios each reaches a maximum. From ∼60 to ∼500  GV, the (p¯/p), (p¯/e+), and (p/e+) flux ratios show no rigidity dependence. These are new observations of the properties of elementary particles in the cosmos.

  9. A Study of the Link between Cosmic Rays and Clouds with a Cloud Chamber at the CERN PS

    CERN Multimedia

    Laakso, L K; Lehtipalo, K; Miettinen, P K; Duarte branco da silva santos, F; Stojkov, Y; Jud, W; Wurm, F; Pinterich, T; Dommen, J; Curtius, J; Kreissl, F C; Minginette, P; Azeredo lima, J M; Kulmala, M T; Petaja, T T; Volkamer, R M; Schafer, M; Rodrigues tome, A; Viisanen, Y A; Onnela, A T O; Kristic, R; Ehrhart, S K; Amorim, A J; Maksumov, O; Kupc, A; Sitals, R P; Dunne, E M; Riipinen, I A; Downard, A J; Virtanen, A; Tsagkogeorgas, G; Schuchmann, S; Kvashnin, A; Hansel, A; Gonzalez carracedo, L R; Vrtala, A; Schallhart, S; Yan, C; Stratmann, F; Pinto mogo, S I; Makhmutov, V; Riccobono, F; Weingartner, E P; Kurten, C A; Rondo, L; Ruuskanen, T M; Finkenzeller, H F; Laaksonen, A J; De menezes, L; Hauser, D; Kajos, M K; Schmitt, T M; Mathot, S; Wasem, A; Guida, R; Metzger, A E; Baltensperger, U; Kirkby, J; Duplissy, J; Franchin, A; Rorup, B; Flagan, R C; Wex, H D

    2002-01-01

    Three recent independent observations suggest that galactic cosmic rays may exert a significant influence on the climate. Firstly, satellite data suggest a positive correlation between variations of cosmic ray intensity and the fraction of Earth covered by low clouds. Secondly, palaeoclimatic data provide extensive evidence for an association between cosmic ray intensity and climate over the last 10 kyr and at earlier times. Finally, the presence of ion-induced nucleation of new aerosol in the atmosphere is supported by recent observations. If cosmic rays do indeed enhance aerosol production and low cloud formation, this could exert a strong cooling influence on the radiative energy balance of Earth. Physical mechanisms by which cosmic rays may affect aerosol and clouds have been proposed and modelled, but definitive experiments are lacking. The aim of CLOUD is to investigate the nature and significance of cosmic ray-aerosol-cloud mechanisms under controlled laboratory conditions using the T11 beam at the CER...

  10. Ultrahigh-energy cosmic rays: facts, myths and legends

    International Nuclear Information System (INIS)

    Anchordoqui, L.A.

    2011-01-01

    This is a written version of a series of lectures aimed at graduate students in astrophysics and theoretical/experimental particle physics. In the first part, we explain the important progress made in recent years towards understanding the experimental data on cosmic rays with energies > or approx. 10 8 GeV. We begin with a brief survey of the available data, including a description of the energy spectrum, mass composition and arrival directions. At this point we also give a short overview of experimental techniques. After that, we introduce the fundamentals of acceleration and propagation in order to discuss the conjectured nearby cosmic-ray sources, and emphasize some of the prospects for a new (multiparticle) astronomy. Next, we survey the state of the art regarding the ultrahigh-energy cosmic neutrinos that should be produced in association with the observed cosmic rays. In the second part, we summarize the phenomenology of cosmic-ray air showers. We explain the hadronic interaction models used to extrapolate results from collider data to ultrahigh energies, and describe the prospects for insights into forward physics at the Large Hadron Collider. We also explain the main electromagnetic processes that govern the longitudinal shower evolution. Armed with these two principal shower ingredients and motivation from the underlying physics, we describe the different methods proposed to distinguish primary species. In the last part, we outline how ultrahigh-energy cosmic-ray interactions can be used to probe new physics beyond the electroweak scale. (author)

  11. Cosmic-ray antiprotons as a probe of a photino-dominated universe

    Science.gov (United States)

    Silk, J.; Srednicki, M.

    1984-01-01

    Observational tests of the hypothesis that the universe is flat and dominated by dark matter in the form of massive photinos include the production of significant fluxes of cosmic rays and gamma rays in our galactic halo. Specification of the cosmological photino density and the masses of scalar quarks and leptons determines the present annihilation rate. The predicted number of low-energy cosmic-ray antiprotons is comparable to the observed flux.

  12. Sensitivity of a search for cosmic ray sources including magnetic field effects

    Energy Technology Data Exchange (ETDEWEB)

    Urban, Martin; Erdmann, Martin; Mueller, Gero [III. Physikalisches Institut A, RWTH Aachen University (Germany)

    2016-07-01

    We analyze the sensitivity of a new method investigating correlations between ultra-high energy cosmic rays and extragalactic sources taking into account deflections in the galactic magnetic field. In comparisons of expected and simulated arrival directions of cosmic rays we evaluate the directional characteristics and magnitude of the field. We show that our method is capable of detecting anisotropy in data sets with a low signal fraction.

  13. Ultra high energy cosmic rays above 10 GeV: Hints to new physics ...

    Indian Academy of Sciences (India)

    Ultra high energy cosmic rays; physics beyond standard model. ... The origin of the observed cosmic ray (CR) events above 10ѕј eV — the so-called ex- .... to arise simply from decay of some supermassive particles (of mass> 10ѕЅ eV) ...

  14. Detection of cosmic ray tracks using scintillating fibers and position sensitive multi-anode photomultipliers

    International Nuclear Information System (INIS)

    Atac, M.; Streets, J.; Wilcer, N.

    1998-02-01

    This experiment demonstrates detection of cosmic ray tracks by using Scintillating fiber planes and multi-anode photomultipliers (MA-PMTs). In a laboratory like this, cosmic rays provide a natural source of high-energy charged particles which can be detected with high efficiency and with nanosecond time resolution

  15. Atomic properties of the elements and cosmic ray composition at the source

    International Nuclear Information System (INIS)

    Casse, M.; Goret, P.; Cesarsky, C.J.

    1975-01-01

    Possible correlations between the abundances of cosmic rays at the source and the solar system abundances are discussed. Cosmic ray source abundances could be explained if the particles are accelerated to injection energies in a dilute, moderately hot plasma, from which they escape in a rigidity dependant fashion [fr

  16. Cosmic Ray Modulation and Radiation Dose of Aircrews During Possible Grand Minimum

    Science.gov (United States)

    Miyake, S.; Kataoka, R.; Sato, T.; Imada, S.; Miyahara, H.; Shiota, D.; Matsumoto, T.; Ueno, H.

    2017-12-01

    The Sun is exhibiting low solar activity levels since the descending phase of the last solar cycle, and it is likely to be continued as well as in the case of the past grand solar minima. The cosmic-ray modulation, which is the variation of the galactic cosmic ray (GCR) spectrum caused by the heliospheric environmental change, is basically anti-correlated with the solar activity. In the recent weak solar cycle, we thus expect that the flux of GCRs is getting higher than that in the previous solar cycles, leading to the increase in the radiation exposure in the space and atmosphere. In order to quantitatively evaluate the possible solar modulation of GCRs and resultant radiation exposure at flight altitude, we have developed the time-dependent and three-dimensional model of the cosmic-ray modulation. Our model can give the flux of GCRs anywhere in the heliosphere by assuming the variation of the solar wind speed, the strength of the heliospheric magnetic field (HMF), and its tilt angle. We solve the gradient-curvature drift motion of GCRs in the HMF, and therefore reproduce the 22-year variation of the cosmic-ray modulation. We also calculate the neutron monitor counting rate and the radiation dose of aircrews at flight altitude, by the air-shower simulation performed by PHITS (Particle and Heavy Ion Transport code System). In our previous study [1], we calculated the radiation dose at a flight altitude during the coming solar cycle by assuming the variation of the solar wind speed and the strength of the HMF expressed by sinusoidal curve, and obtained that an annual radiation dose of aircrews in 5 years around the next solar minimum will be up to 19% higher than that at the last cycle. In this study, we predict the new model of the heliospheric environmental change on the basis of a prediction model for the sunspot number. The quantitative predictions of the cosmic-ray modulation and the radiation dose at a flight altitude during possible Grand Minimum considering

  17. The origins of cosmic rays and quantum effects on gravity

    Science.gov (United States)

    Tomozawa, Y.

    1985-01-01

    The energy spectrum of primary cosmic rays is explained by particles emitted during a thermal expansion of explosive objects inside and near the galaxy, remnants of which may be supernova and/or active talaxies, or even stars or galaxies that disappeared from our sight after the explosion. A power law energy spectrum for cosmic rays, E to the (-alpha -1, is obtained from an expansion rate T is proportional to R to the alpha. Using the solution of the Einstein equation, we obtain a spectrum which agrees very well with experimental data. The implication of an inflationary early universe on the cosmic ray spectrum is also discussed. It is also suggested that the conflict between this model and the singularity theorem in classical general relativity may be eliminated by quantum effects.

  18. The puzzle of the ultra-high energy cosmic rays

    CERN Document Server

    Tkachev, I I

    2003-01-01

    In early years the cosmic ray studies were ahead of accelerator research, starting from the discovery of positrons, through muons, to that of pions and strange particles. Today we are facing the situation that the puzzling saga of cosmic rays of the highest energies may again unfold in the discovery of new physics, now beyond the Standard Model; or it may bring to life an "extreme" astrophysics. After a short review of the Greisen-Zatsepin-Kuzmin puzzle, I discuss different models which were suggested for its resolution. Are there any hints pointing to the correct model? I argue that the small-scale clustering of arrival directions of cosmic rays gives a clue, and BL Lacs are the probable sources of the observed events. (58 refs).

  19. FPGA development board for applications in cosmic rays physics

    International Nuclear Information System (INIS)

    Angelov, Ivo; Damov, Krasimir; Dimitrova, Svetla

    2013-01-01

    The modern experiments in cosmic rays and particle physics are usually performed with large number of detectors and signal processing have to be done by complex electronics. The analog signals from the detectors are converted to digital (by discriminators or fast ADC) and connected to different type of logic implemented in FPGA (Field Programmable Gate Arrays). A FPGA development board based on Xilinx XC3S50AN was designed, assembled and tested. The board will be used for developing a modern registering controller (to replace the existing now) for the muon telescope in the University and can be used for other experiments in cosmic rays physics when fast digital pulses have to be processed. Keywords: FPGA, Spartan3A, muon telescope, cosmic rays variations

  20. Field testing for cosmic ray soft errors in semiconductor memories

    International Nuclear Information System (INIS)

    O'Gorman, T.J.; Ross, J.M.; Taber, A.H.; Ziegler, J.F.; Muhlfeld, H.P.; Montrose, C.J.; Curtis, H.W.; Walsh, J.L.

    1996-01-01

    This paper presents a review of experiments performed by IBM to investigate the causes of soft errors in semiconductor memory chips under field test conditions. The effects of alpha-particles and cosmic rays are separated by comparing multiple measurements of the soft-error rate (SER) of samples of memory chips deep underground and at various altitudes above the earth. The results of case studies on four different memory chips show that cosmic rays are an important source of the ionizing radiation that causes soft errors. The results of field testing are used to confirm the accuracy of the modeling and the accelerated testing of chips

  1. Cosmic ray radio emission as air shower detection

    International Nuclear Information System (INIS)

    Curutiu, Alexandru; Rusu, Mircea; Isar, Gina; Zgura, Sorin

    2004-01-01

    The possibility of radio-detection of ultra-high energy cosmic rays (within the 10 to 100 MHz range) are discussed. Currently, air showers are detected by various methods, mainly based on particle detectors (KASCADE, Auger) or optical detection (Cerenkov radiation). Recently,to detect radio emission from cosmic ray air showers a method using electromagnetic radiation in low frequency domain (LOFAR) was proposed. We are investigating this possibility, using simulation codes created to investigate electromagnetic radiation of intricate antennae structure, for example fractal antennas. Some of the preliminary results will be communicated in this session. (authors)

  2. Cosmic-ray shock acceleration in oblique MHD shocks

    Science.gov (United States)

    Webb, G. M.; Drury, L. OC.; Volk, H. J.

    1986-01-01

    A one-dimensional, steady-state hydrodynamical model of cosmic-ray acceleration at oblique MHD shocks is presented. Upstream of the shock the incoming thermal plasma is subject to the adverse pressure gradient of the accelerated particles, the J x B force, as well as the thermal gas pressure gradient. The efficiency of the acceleration of cosmic-rays at the shock as a function of the upstream magnetic field obliquity and upstream plasma beta is investigated. Astrophysical applications of the results are briefly discussed.

  3. Cosmic Ray Positrons from Pulsars

    Science.gov (United States)

    Harding, Alice K.

    2010-01-01

    Pulsars are potential Galactic sources of positrons through pair cascades in their magnetospheres. There are, however, many uncertainties in establishing their contribution to the local primary positron flux. Among these are the local density of pulsars, the cascade pair multiplicities that determine the injection rate of positrons from the pulsar, the acceleration of the injected particles by the pulsar wind termination shock, their rate of escape from the pulsar wind nebula, and their propagation through the interstellar medium. I will discuss these issues in the context of what we are learning from the new Fermi pulsar detections and discoveries.

  4. Solar, Stellar and Galactic Connections between Particle Physics and Astrophysics

    CERN Document Server

    Carraminana, Alberto

    2007-01-01

    This book collects extended and specialized reviews on topics linking astrophysics and particle physics at a level intermediate between a graduate student and a young researcher. The book includes also three reviews on observational techniques used in forefront astrophysics and short articles on research performed in Latin America. The reviews, updated and written by specialized researchers, describe the state of the art in the related research topics. This book is a valuable complement not only for research but also for lecturers in specialized course of high energy astrophysics, cosmic ray astrophysics and particle physics.

  5. Cosmological cosmic rays: Sharpening the primordial lithium problem

    International Nuclear Information System (INIS)

    Prodanovic, Tijana; Fields, Brian D.

    2007-01-01

    Cosmic structure formation leads to large-scale shocked baryonic flows which are expected to produce a cosmological population of structure-formation cosmic rays (SFCRs). Interactions between SFCRs and ambient baryons will produce lithium isotopes via α+α→ 6,7 Li. This pre-galactic (but nonprimordial) lithium should contribute to the primordial 7 Li measured in halo stars and must be subtracted in order to arrive to the true observed primordial lithium abundance. In this paper we point out that the recent halo star 6 Li measurements can be used to place a strong constraint to the level of such contamination, because the exclusive astrophysical production of 6 Li is from cosmic-ray interactions. We find that the putative 6 Li plateau, if due to pre-galactic cosmic-ray interactions, implies that SFCR-produced lithium represents Li SFCR /Li plateau ≅15% of the observed elemental Li plateau. Taking the remaining plateau Li to be cosmological 7 Li, we find a revised (and slightly worsened) discrepancy between the Li observations and big bang nucleosynthesis predictions by a factor of 7 Li BBN / 7 Li plateau ≅3.7. Moreover, SFCRs would also contribute to the extragalactic gamma-ray background (EGRB) through neutral pion production. This gamma-ray production is tightly related to the amount of lithium produced by the same cosmic rays; the 6 Li plateau limits the pre-galactic (high-redshift) SFCR contribution to be at the level of I γ π SFCR /I EGRB < or approx. 5% of the currently observed EGRB

  6. Key scientific problems from Cosmic Ray History

    Science.gov (United States)

    Lev, Dorman

    2016-07-01

    young scientist from the Graz University, started to investigate how γ-radiations change their intensity with the distance from their sources, i.e. from the ground. When he performed his historical experiments on balloons in 1911-1912, it was found that at the beginning (up to approximately one km) ionization did not change, but with increase of the altitude for up to 4 - 5 km, the ionization rate escalates several times. Victor Hess drew a conclusion that some new unknown source of ionization of extra terrestrial origin exists. He named it 'high altitude radiation'. 5. Many scientists did not agree with this conclusion and tried to prove that the discovered new radiation has terrestrial origin (e.g., radium and other emanations from radioactive substances in the ground, particle acceleration up to high energies during thunderstorms, and so on). However, a lot of experiments showed that Victor Hess's findings are right: the discovered new radiation has extra terrestrial origin. 6. In 1926 the great American scientist Robert Millikan named them 'cosmic rays': cosmic as coming from space, and rays because it was generally wrongly accepted at those time that the new radiation mostly consisted of γ-rays. Robert Millikan believed that God exists and continues to work: in space God has creates He atoms from four atoms of H with the generation high energy gamma rays (in contradiction with physical laws, as this reaction can occur only at very high temperature and great density, e.g., as inside stars). 7. On this problem, interesting to many people, there was a famous public discussion between two Nobel laureates Arthur Compton and Robert Millikan, widely reported in newspapers. Only after a lot of latitude surveys in the 1930s, organized mostly by Compton and Millikan, it became clear that 'cosmic rays' are mostly not γ-rays, but rather charged particles (based on Störmer's theory about behavior of charged energetic particles in the geomagnetic field, developed in 1910

  7. Receiver system for radio observation of high-energy cosmic ray air showers and its behaviour in self trigger mode

    International Nuclear Information System (INIS)

    Kroemer, Oliver

    2008-04-01

    on the site of the cosmic ray air shower experiment KASCADE-Grande at the Forschungszentrum Karlsruhe. They are receiving radio signals which are clearly in coincidence with cosmic ray air showers. Due to the calibration spanning the whole signal path and the polarization analysis it is possible to investigate radio emission from cosmic ray air showers and underlying emission models. An autonomous operation of the receiver stations requires a self trigger which identifies the cosmic ray air shower by its own radio signal only. Due to the superposition of noise and radio frequency interference an increasing false trigger rate is expected with decreasing trigger threshold. The self trigger conceived within this work allows suitably low thresholds at technically manageable false trigger rates. The behaviour and limitations of this self trigger concept are derived theoretically but also confirmed by measurements under real environmental conditions. On the radio-loud site of the Forschungszentrum Karlsruhe, the electric field strength threshold is only a factor of 3 above the theoretical minimum which is given by the omnipresent galactic noise in an unpopulated environment. The resulting detection limits for cosmic rays are expected to be above 5.10 17 eV for the primary particle energies in an unpopulated environment and above 10 18 eV on the site of the Forschungszentrum Karlsruhe. (orig.)

  8. A time-averaged cosmic ray propagation theory

    International Nuclear Information System (INIS)

    Klimas, A.J.

    1975-01-01

    An argument is presented, which casts doubt on our ability to choose an appropriate magnetic field ensemble for computing the average behavior of cosmic ray particles. An alternate procedure, using time-averages rather than ensemble-averages, is presented. (orig.) [de

  9. The mass composition of cosmic rays measured with LOFAR

    NARCIS (Netherlands)

    Hörandel, Jörg R.; Bonardi, A.; Buitink, S.; Corstanje, A.; Falcke, H.; Mitra, P.; Mulrey, K.; Nelles, A.; Rachen, J. P.; Rossetto, L.; Schellart, P.; Scholten, O.; ter Veen, S.; Thoudam, S.; Trinh, T. N. G.; Winchen, T.

    2017-01-01

    High-energy cosmic rays, impinging on the atmosphere of the Earth initiate cascades of secondary particles, the extensive air showers. The electrons and positrons in the air shower emit electromagnetic radiation. This emission is detected with the LOFAR radio telescope in the frequency range from 30

  10. Search for magnetic monopoles at the Chacaltaya cosmic ray laboratory

    International Nuclear Information System (INIS)

    Cecchini, S.; Giacomelli, G.; Giorgini, M.; Mandrioli, G.; Manzoor, S.; Margiotta, A.; Patrizii, L.; Popa, V.; Serra, P.; Spurio, M.; Togo, V.; Zanini, A.; Saavedra, O.; Zanini, A.; McDonald, J.; Pinfold, J.; Manzoor, S.; Rana, M. A.; Qureshi, I. E.; Shahzad, M. I.; Popa, V.; Ticona, R.; Velarde, A.; Cechini, S.

    2001-01-01

    The new large area (400 m 2 ) experiment - SLIM - to search for magnetic monopoles and other exotic massive particles is presented. It uses of nuclear track detectors and is being deployed at the Chacaltaya cosmic ray laboratory for at least 4 years. The detection capability of the experiment is discussed

  11. Cosmic ray zenith angle distribution at low geomagnetic latitude

    Energy Technology Data Exchange (ETDEWEB)

    Aragon, G [Instituto de Astronomia y Fisica del Espacio, Buenos Aires, Argentina; Gagliardini, A; Ghielmetti, H S

    1977-12-01

    The intensity of secondary charged cosmic rays at different zenith angles was measured by narrow angle Geiger-Mueller telescopes up to an atmospheric depth of 2 g cm/sup -2/. The angular distribution observed at high altitudes is nearly flat at small angles around the vertical and suggests that the particle intensity peaks at large zenith angles, close to the horizon.

  12. Super-TIGER-2: A Very-Large-Area, High-Resolution Trans-Iron Cosmic Ray Investigation

    Science.gov (United States)

    Binns, Walter

    predominately r-process nuclei. Super-TIGER has unique capabilities to address the APRA program solicitation for investigations of particles of cosmic origin and will advance our understanding of the fundamental operational aspects of detectors for future space flight missions. As a dedicated UHCR instrument, Super-TIGER provides critical measurements to unravel the mystery of galactic cosmic ray (GCR) origins and complements instruments with different observational aims including AMS, CALET, BESS-Polar, CREAM, TRACER, Fermi, and PAMELA.

  13. Flipped cryptons and ultrahigh energy cosmic rays

    CERN Document Server

    Ellis, Jonathan Richard; Nanopoulos, D V

    2004-01-01

    Cryptons are metastable bound states of fractionally-charged particles that arise generically in the hidden sectors of models derived from heterotic string. We study their properties and decay modes in a specific flipped SU(5) model with long-lived four-particle spin-zero bound states called tetrons. We show that the neutral tetrons are metastable, and exhibit the tenth order nonrenormalizable superpotential operators responsible for their dominant decays. By analogy with QCD, we expect charged tetrons to be somewhat heavier, and to decay relatively rapidly via lower-order interactions that we also exhibit. The expected masses and lifetimes of the neutral tetrons make them good candidates for cold dark matter, and a potential source of the ultrahigh energy cosmic rays which have been observed, whereas the charged tetrons would have decayed in the early Universe.

  14. Ultra-High-Energy Cosmic Rays

    CERN Document Server

    Dova, M.T.

    2015-05-22

    The origin of the ultra high energy cosmic rays (UHECR) with energies above E > 10 17 eV, is still unknown. The discovery of their sources will reveal the engines of the most energetic astrophysical accelerators in the universe. This is a written version of a series of lectures devoted to UHECR at the 2013 CERN-Latin-American School of High-Energy Physics. We present anintroduction to acceleration mechanisms of charged particles to the highest energies in astrophysical objects, their propagation from the sources to Earth, and the experimental techniques for their detection. We also discuss some of the relevant observational results from Telescope Array and Pierre Auger Observatory. These experiments deal with particle interactions at energies orders of magnitude higher than achieved in terrestrial accelerators.

  15. International Conference on Cosmic Rays

    CERN Multimedia

    W.O. LOCK

    1964-01-01

    Towards the end of last year the 8th International conference on cosmic rays, held under the auspices of the International Union of Pure and Applied Physics (I.U.P.A.P.) and the Department of Atomic Energy of the Government of India, was held at Jaipur, India. Among the participants was W.O. Lock, head of CERN's Emulsion Group, who gave an invited talk on recent work in the field of what is normally known as high-energy physics — though in the context of this conference such energies seem quite low. In this article, Dr. Lock gives a general review of the conference and of the subjects discussed.

  16. Ground level cosmic ray observations

    Energy Technology Data Exchange (ETDEWEB)

    Stephens, S.A. [Tata Institute of Fundamental Research, Bombay (International Commission on Radiation Units and Measurements); Grimani, C.; Brunetti, M.T.; Codino, A. [Perugia Univ. (Italy)]|[INFN, Perugia (Italy); Papini, P.; Massimo Brancaccio, F.; Piccardi, S. [Florence Univ. (Italy)]|[INFN, Florence (Italy); Basini, G.; Bongiorno, F. [INFN, Laboratori Nazionali di Frascati, Rome (Italy); Golden, R.L. [New Mexico State Univ., Las Cruces, NM (United States). Particle Astrophysics Lab.; Hof, M. [Siegen Univ. (Germany). Fachbereich Physik

    1995-09-01

    Cosmic rays at ground level have been collected using the NMSU/Wizard - MASS2 instrument. The 17-hr observation run was made on September 9. 1991 in Fort Sumner, New Mexico, Usa. Fort Sumner is located at 1270 meters a.s.l., corresponding to an atmospheric depth of about 887 g/cm{sup 2}. The geomagnetic cutoff is 4.5 GV/c. The charge ratio of positive and negative muons and the proton to muon ratio have been determined. These observations will also be compared with data collected at a higher latitude using the same basic apparatus.

  17. High energy cosmic ray astronomy

    International Nuclear Information System (INIS)

    Fonseca, V.

    1996-01-01

    A brief introduction to High Energy Cosmic Ray Astronomy is presented. This field covers a 17 decade energy range (2.10 4 -10 20 ) eV. Recent discoveries done with gamma-ray detectors on-board satellites and ground-based Cherenkov devices are pushing for a fast development of new and innovative techniques, specially in the low energy region which includes the overlapping of satellite and ground-based measurements in the yet unexplored energy range 20 keV-250 GeV. Detection of unexpected extremely high energy events have triggered the interest of the international scientific community. (orig.)

  18. Solar flares and the cosmic ray intensity

    International Nuclear Information System (INIS)

    Hatton, C.J.

    1980-01-01

    The relationship between the cosmic ray intensity and solar activity during solar cycle 20 is discussed. A model is developed whereby it is possible to simulate the observed cosmic ray intensity from the observed number of solar flares of importance >= 1. This model leads to a radius for the modulation region of 60-70 AU. It is suggested that high speed solar streams also made a small contribution to the modulation of cosmic rays during solar cycle 20. (orig.)

  19. Ultrahigh Energy Cosmic Rays: Facts, Myths, and Legends

    CERN Document Server

    Anchordoqui, Luis Alfredo

    2013-06-27

    This is a written version of a series of lectures aimed at graduate students in astrophysics/particle theory/particle experiment. In the first part, we explain the important progress made in recent years towards understanding the experimental data on cosmic rays with energies > 10^8 GeV. We begin with a brief survey of the available data, including a description of the energy spectrum, mass composition, and arrival directions. At this point we also give a short overview of experimental techniques. After that, we introduce the fundamentals of acceleration and propagation in order to discuss the conjectured nearby cosmic ray sources, and emphasize some of the prospects for a new (multi-particle) astronomy. Next, we survey the state of the art regarding the ultrahigh energy cosmic neutrinos which should be produced in association with the observed cosmic rays. In the second part, we summarize the phenomenology of cosmic ray air showers. We explain the hadronic interaction models used to extrapolate results from ...

  20. Ultrahigh energy cosmic rays from nearby starburst galaxies

    Science.gov (United States)

    Attallah, Reda; Bouchachi, Dallel

    2018-04-01

    Ultrahigh energy cosmic rays are the most energetic of any subatomic particles ever observed in nature. The quest for their mysterious origin is currently a major scientific challenge. Here we explore the possibility that these particles originate from nearby starburst galaxies, a scenario that matches the recent observation by the Telescope Array experiment of a cosmic-ray hotspot above 57 EeV not far from the direction of the starburst galaxy M82. Specifically, we study the stochastic propagation in space of ultrahigh energy cosmic rays through the state-of-the-art simulation framework CRPropa 3, taking into account all relevant particle interactions as well as deflections by the intervening magnetic fields. To ensure a comprehensive understanding of this model, we consider the energy spectrum, the cosmogenic neutrinos and gamma rays, and the distribution of arrival directions. The starburst galaxy scenario reproduces well observations from both the Telescope Array and Pierre Auger Observatories, making it very attractive for explaining the origin of cosmic rays at the highest energies.

  1. Solar cycle variation of cosmic ray intensity along with interplanetary and solar wind plasma parameters

    International Nuclear Information System (INIS)

    Mishra, R.K.; Tiwari, S.; Agarwal, R.

    2008-01-01

    Galactic cosmic rays are modulated at their propagation in the heliosphere by the effect of the large-scale structure of the interplanetary medium. A comparison of the variations in the cosmic ray intensity data obtained by neutron monitoring stations with those in geomagnetic disturbance, solar wind velocity (V), interplanetary magnetic field (B), and their product (V , B) near the Earth for the period 1964-2004 has been presented so as to establish a possible correlation between them. We used the hourly averaged cosmic ray counts observed with the neutron monitor in Moscow. It is noteworthy that a significant negative correlation has been observed between the interplanetary magnetic field, product (V , B) and cosmic ray intensity during the solar cycles 21 and 22. The solar wind velocity has a good positive correlation with cosmic ray intensity during solar cycle 21, whereas it shows a weak correlation during cycles 20, 22 and 23. The interplanetary magnetic field shows a weak negative correlation with cosmic rays for solar cycle 20, and a good anti-correlation for solar cycles 21-23 with the cosmic ray intensity, which, in turn, shows a good positive correlation with disturbance time index (Dst) during solar cycles 21 and 22, and a weak correlation for cycles 20 and 23. (Authors)

  2. Cosmic-ray-veto detector system

    International Nuclear Information System (INIS)

    Miller, D.W.; Menlove, H.O.

    1992-12-01

    To reduce the cosmic-ray-induced neutron background, we are testing a cosmic-ray veto option with a neutron detector system that uses plastic scintillator slabs mounted on the outside of a 3 He-tube detector. The scintillator slabs eliminate unwanted cosmic-ray events, enabling the detector to assay low-level plutonium samples, for which a low-background coincident signature is critical. This report describes the design and testing of the prototype cosmic-ray-veto detector system

  3. Towards a Unified Source-Propagation Model of Cosmic Rays

    Science.gov (United States)

    Taylor, M.; Molla, M.

    2010-07-01

    report that the entire spectrum, spanning cosmic rays of local solar origin and those eminating from galactic and extra-galactic sources can be explained using a new diagnostic — the gradient of the log-log plot. This diagnostic reveals the known Boltmann statistics in the solar-terrestrial neighbourhood but at the highest energies — presumably at the cosmic ray source, with clearly separated fractal scales in between. We interpret this as modulation at the source followed by Fermi acceleration facilitated by galactic and extra-galactic magnetic fields with a final modulation in the solar-terrestrial neighbourhood. We conclude that the gradient of multifractal curves appears to be an excellent detector of fractality.

  4. Cosmic ray diffusion: report of the workshop in cosmic ray diffusion theory

    International Nuclear Information System (INIS)

    Birmingham, T.J.; Jones, F.C.

    1975-02-01

    A workshop in cosmic ray diffusion theory was held at Goddard Space Flight Center on May 16-17, 1974. Topics discussed and summarized are: (1) cosmic ray measurements as related to diffusion theory; (2) quasi-linear theory, nonlinear theory, and computer simulation of cosmic ray pitch-angle diffusion; and (3) magnetic field fluctuation measurements as related to diffusion theory. (auth)

  5. Simulation of the charge ratio of cosmic ray muons in extensive air showers using CORSIKA

    Energy Technology Data Exchange (ETDEWEB)

    Ochilo, Livingstone [University of Siegen (Germany); Kenyatta University, Nairobi (Kenya); Hashim, Nadir; Okumu, John [Kenyatta University, Nairobi (Kenya)

    2013-07-01

    The interaction of primary cosmic rays in the atmosphere produces, among other particles, pions and kaons. They decay to muons, which form an important component of extensive air showers. The ratio of positively to negatively charged muons, called the muon charge ratio, provides important information about the cosmic ray interactions in the atmosphere. In this study, the theoretical hadronic interaction models in the cosmic ray simulation code CORSIKA have been used to study the charge ratio of cosmic ray muons simulated in extensive air showers. An East - West effect on the charge ratio of simulated cosmic ray muons is observed. It is more pronounced for inclined and low-energy muons (momentum less than 100 GeV/c and zenith angle greater than 80 ). Experimental data from ''MINOS Near'' experiment gives similar results.

  6. Modelling cosmic ray intensities along the Ulysses trajectory

    Directory of Open Access Journals (Sweden)

    D. C. Ndiitwani

    2005-03-01

    Full Text Available Time dependent cosmic ray modulation in the inner heliosphere is studied by comparing results from a 2-D, time-dependent cosmic ray transport model with Ulysses observations. A compound approach, which combines the effects of the global changes in the heliospheric magnetic field magnitude with drifts to establish a realistic time-dependence, in the diffusion and drift coefficients, are used. We show that this model results in realistic cosmic ray modulation from the Ulysses launch (1990 until recently (2004 when compared to 2.5-GV electron and proton and 1.2-GV electron and Helium observations from this spacecraft. This approach is also applied to compute radial gradients present in 2.5-GV cosmic ray electron and protons in the inner heliosphere. The observed latitude dependence for both positive and negative charged particles during both the fast latitude scan periods, corresponding to different solar activity conditions, could also be realistically computed. For this an additional reduction in particle drifts (compared to diffusion toward solar maximum is needed. This results in a realistic charge-sign dependent modulation at solar maximum and the model is also applied to predict charge-sign dependent modulation up to the next expected solar minimum.

  7. Cosmic Ray Physics with the KASCADE-Grande Observatory

    Science.gov (United States)

    Arteaga-Velázquez, J. C.; Apel, W. D.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Fuhrmann, D.; Gherghel-Lascu, A.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huege, T.; Kampert, K.-H.; Kang, D.; Klages, H. O.; Link, K.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Oehlschläger, J.; Ostapchenko, S.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schoo, S.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Zabierowski, J.

    The existence of a knee at a few PeV in the all-particle cosmic ray energy spectrum has been well established by several experiments but its physical origin has eluded researches for a long time. It is believed that keys to disentangle the mystery could be found in the spectrum and the composition of cosmic rays between 1 PeV and 1 EeV. A first detailed look into the elemental chemical abundances of cosmic rays in this energy regime was provided by both the KASCADE and the KASCADE-Grande experiments. Their measurements opened the door to a wealth of new data on the subject, which led to the discovery of new structures in the all-particle energy spectrum and the confirmation of knee-like features in the spectra of individual mass groups, as well as the observation of an unexpected ankle-like structure at around 100 PeV in the flux of the light component of cosmic rays. In this contribution, early findings with the KASCADE-Grande experiment will be reviewed and then a short update on the analyses currently performed with the data of the observatory will be presented.

  8. Cosmic ray anisotropies at high energies

    Science.gov (United States)

    Martinic, N. J.; Alarcon, A.; Teran, F.

    1986-01-01

    The directional anisotropies of the energetic cosmic ray gas due to the relative motion between the observers frame and the one where the relativistic gas can be assumed isotropic is analyzed. The radiation fluxes formula in the former frame must follow as the Lorentz invariance of dp/E, where p, E are the 4-vector momentum-energy components; dp is the 3-volume element in the momentum space. The anisotropic flux shows in such a case an amplitude, in a rotating earth, smaller than the experimental measurements from say, EAS-arrays for primary particle energies larger than 1.E(14) eV. Further, it is shown that two consecutive Lorentz transformations among three inertial frames exhibit the violation of dp/E invariance between the first and the third systems of reference, due to the Wigner rotation. A discussion of this result in the context of the experimental anisotropic fluxes and its current interpretation is given.

  9. Muon acceleration in cosmic-ray sources

    International Nuclear Information System (INIS)

    Klein, Spencer R.; Mikkelsen, Rune E.; Becker Tjus, Julia

    2013-01-01

    Many models of ultra-high energy cosmic-ray production involve acceleration in linear accelerators located in gamma-ray bursts, magnetars, or other sources. These transient sources have short lifetimes, which necessitate very high accelerating gradients, up to 10 13 keV cm –1 . At gradients above 1.6 keV cm –1 , muons produced by hadronic interactions undergo significant acceleration before they decay. This muon acceleration hardens the neutrino energy spectrum and greatly increases the high-energy neutrino flux. Using the IceCube high-energy diffuse neutrino flux limits, we set two-dimensional limits on the source opacity and matter density, as a function of accelerating gradient. These limits put strong constraints on different models of particle acceleration, particularly those based on plasma wake-field acceleration, and limit models for sources like gamma-ray bursts and magnetars.

  10. Statistical reconstruction for cosmic ray muon tomography.

    Science.gov (United States)

    Schultz, Larry J; Blanpied, Gary S; Borozdin, Konstantin N; Fraser, Andrew M; Hengartner, Nicolas W; Klimenko, Alexei V; Morris, Christopher L; Orum, Chris; Sossong, Michael J

    2007-08-01

    Highly penetrating cosmic ray muons constantly shower the earth at a rate of about 1 muon per cm2 per minute. We have developed a technique which exploits the multiple Coulomb scattering of these particles to perform nondestructive inspection without the use of artificial radiation. In prior work [1]-[3], we have described heuristic methods for processing muon data to create reconstructed images. In this paper, we present a maximum likelihood/expectation maximization tomographic reconstruction algorithm designed for the technique. This algorithm borrows much from techniques used in medical imaging, particularly emission tomography, but the statistics of muon scattering dictates differences. We describe the statistical model for multiple scattering, derive the reconstruction algorithm, and present simulated examples. We also propose methods to improve the robustness of the algorithm to experimental errors and events departing from the statistical model.

  11. PREFACE: 23rd European Cosmic Ray Symposium (and 32nd Russian Cosmic Ray Conference)

    Science.gov (United States)

    Erlykin, A. D.; Kokoulin, R. P.; Lidvansky, A. S.; Meroshnichenko, L. I.; Panasyuk, M. I.; Panov, A. D.; Wolfendale, A. W.

    2013-02-01

    The 23rd European Cosmic Ray Symposium (ECRS) took place in Moscow at the Lomonosov Moscow State University (3-7 July 2012), and was excellently organized by the Skobeltsyn Institute of Nuclear Physics of the Lomonosov Moscow State University, with the help of the Russian Academy of Sciences and the Council on the Complex Problem of Cosmic Rays of the Russian Academy of Sciences. The first symposia were held in 1968 in Lodz, Poland (high energy, extensive air showers and astrophysical aspects) and in Bern (solar and heliospheric phenomena) and the two 'strands' joined together in 1976 with the meeting in Leeds. Since then the symposia, which have been very successful, have covered all the major topics with some emphasis on European collaborations and on meeting the demands of young scientists. Initially, a driving force was the need to overcome the divisions caused by the 'Cold War' but the symposia continued even when that threat ceased and they have shown no sign of having outlived their usefulness. 2012 has been an important year in the history of cosmic ray studies, in that it marked the centenary of the discovery of enigmatic particles in the perilous balloon ascents of Victor Hess. A number of conferences have taken place in Western Europe during the year, but this one took place in Moscow as a tribute to the successful efforts of many former USSR and other Eastern European scientists in discovering the secrets of the subject, often under very difficult conditions. The symposium covers a wide range of scientific issues divided into the following topics: PCR-IPrimary cosmic rays I (E 1015 eV) MNCosmic ray muons and neutrinos GAGeV and TeV gamma astronomy SHEnergetic particles in the heliosphere (solar and anomalous CRs and GCR modulation) GEOCosmic rays and geophysics (energetic particles in the atmosphere and magnetosphere of the Earth) On a personal note, as I step down as co-founder and chairman of the International Advisory Committee, I should like to

  12. From radio signals to cosmic rays

    International Nuclear Information System (INIS)

    Riviere, C.

    2009-12-01

    Radio detection of high energy cosmic rays is currently being reinvested, both on the experimental and theoretical sides. The question is to know whether radio-detection is a competitive technique compared or in addition to usual detection techniques; in order to increase statistics at the highest energies (around 10 20 eV - where particle astronomy should be possible) or to characterize precisely the cosmic rays at lower energies (some 10 18 eV). During this work, we tried to progress towards the answer, using radio emission models, experimental data analysis and preparing the next generation of detectors. On the theoretical side, geo-synchrotron emission of the particles of the showers has been computed analytically using a simplified shower model as well as using the Monte Carlo simulation AIRES to have a realistic shower development. Various dependencies of the electric field have been extracted, among which a proportionality of the field with the -v → * B → vector under certain conditions. Experimentally, the analysis of CODALEMA data enabled to characterise more precisely the electric field produced by air showers, in particular the topology of the field at ground level, the energy dependency and the coherence with a -v → * B → proportionality. These results are summarised in an overall parametrization of the electric field. More data are probably required in order to give a definitive statement on the interest of the radio-detection technique. The CODALEMA parametrization has finally been used to extrapolate CODALEMA's results to a future larger array, extrapolation applied in particular to the AERA detector of the Pierre Auger Observatory. (author)

  13. Cosmic rays around 1018 eV: Implications of contemporary measurements on the origin of the ankle feature

    International Nuclear Information System (INIS)

    Deligny, O.

    2014-01-01

    The impressive power-law decay of the energy spectrum of cosmic rays over more than thirty orders of magnitude in intensity and for energies ranging over eleven decades between 10 9 eV and 10 20 eV is actually dotted with small irregularities. These irregularities are highly valuable for uncovering and understanding the modes of production and propagation of cosmic rays. They manifest themselves through changes in the spectral index characterising the observed power laws. One of these irregularities, known as the ankle, is a hardening of the energy spectrum of cosmic rays in the 10 18 eV energy range. There are many possible interpretations for explaining it. One is to say that the ankle may be the spectral feature marking the transition between Galactic and extragalactic cosmic rays. Another one is to understand the ankle as the natural distortion of a proton-dominated extragalactic spectrum due to e ± pair production in the collisions with the photons of the cosmic microwave background. While the data collected at the Telescope Array supports the second explanation, the data collected at the Pierre Auger Observatory requires a totally different picture in terms of introducing a new component mainly composed of light elements in order to fill the gap of the all-particle energy spectrum between 10 17 eV and 4*10 18 eV, and to reproduce the measurements related to mass composition. If contemporary observations characterising the ankle have shed new lights, they are still far from being able to deliver all the story

  14. The Cosmic-ray Spectrum: from the knee to the ankle

    International Nuclear Information System (INIS)

    Gaisser, T K

    2006-01-01

    This talk addresses the question, 'Where is the transition from cosmic rays of galactic origin to extra-galactic cosmic-rays?' I have addressed the background of this topic recently in lectures at Erice and, with Todor Stanev, in a collection of papers on various aspects of nuclear astrophysics. Here I concentrate on primary composition as a signature of the transition and mention some new air-shower experiments aimed at the energy region from the knee to the ankle (PeV to 10 EeV)

  15. The energy spectrum of cosmic-ray electrons measured with H.E.S.S

    International Nuclear Information System (INIS)

    Egberts, Kathrin

    2009-01-01

    The spectrum of cosmic-ray electrons has so far been measured using balloon and satellite-based instruments. At TeV energies, however, the sensitivity of such instruments is very limited due to the low flux of electrons at very high energies and small detection areas of balloon/satellite based experiments. The very large collection area of ground-based imaging atmospheric Cherenkov telescopes gives them a substantial advantage over balloon/ satellite based instruments when detecting very-high-energy electrons (> 300 GeV). By analysing data taken by the High Energy Stereoscopic System (H.E.S.S.), this work extends the known electron spectrum up to 4 TeV - a range that is not accessible to direct measurements. However, in contrast to direct measurements, imaging atmospheric Cherenkov telescopes such as H.E.S.S. detect air showers that cosmic-ray electrons initiate in the atmosphere rather than the primary particle. Thus, the main challenge is to differentiate between air showers initiated by electrons and those initiated by the hadronic background. A new analysis technique was developed that determines the background with the support of the machine-learning algorithm Random Forest. It is shown that this analysis technique can also be applied in other areas such as the analysis of diffuse γ rays from the Galactic plane. (orig.)

  16. The energy spectrum of cosmic-ray electrons measured with H.E.S.S.

    Energy Technology Data Exchange (ETDEWEB)

    Egberts, Kathrin

    2009-03-30

    The spectrum of cosmic-ray electrons has so far been measured using balloon and satellite-based instruments. At TeV energies, however, the sensitivity of such instruments is very limited due to the low flux of electrons at very high energies and small detection areas of balloon/satellite based experiments. The very large collection area of ground-based imaging atmospheric Cherenkov telescopes gives them a substantial advantage over balloon/ satellite based instruments when detecting very-high-energy electrons (> 300 GeV). By analysing data taken by the High Energy Stereoscopic System (H.E.S.S.), this work extends the known electron spectrum up to 4 TeV - a range that is not accessible to direct measurements. However, in contrast to direct measurements, imaging atmospheric Cherenkov telescopes such as H.E.S.S. detect air showers that cosmic-ray electrons initiate in the atmosphere rather than the primary particle. Thus, the main challenge is to differentiate between air showers initiated by electrons and those initiated by the hadronic background. A new analysis technique was developed that determines the background with the support of the machine-learning algorithm Random Forest. It is shown that this analysis technique can also be applied in other areas such as the analysis of diffuse {gamma} rays from the Galactic plane. (orig.)

  17. Ultra high-energy cosmic ray composition

    International Nuclear Information System (INIS)

    Longley, N.P.

    1993-01-01

    The Soudan 2 surface-underground cosmic ray experiment can simultaneously measure surface shower size, underground muon multiplicity, and underground muon separation for ultra high energy cosmic ray showers. These measurements are sensitive to the primary composition. Analysis for energies from 10 1 to 10 4 TeV favors a light flux consisting of predominantly H and He nuclei

  18. Sealed drift tube cosmic ray veto counters

    International Nuclear Information System (INIS)

    Rios, R.; Tatar, E.; Bacon, J.D.; Bowles, T.J.; Hill, R.; Green, J.A.; Hogan, G.E.; Ito, T.M.; Makela, M.; Morris, C.L.; Mortenson, R.; Pasukanics, F.E.; Ramsey, J.; Saunders, A.; Seestrom, S.J.; Sondheim, W.E.; Teasdale, W.; Saltus, M.; Back, H.O.; Cottrell, C.R.

    2011-01-01

    We describe a simple drift tube counter that has been used as a cosmic ray veto for the UCNA experiment, a first-ever measurement of the neutron beta-asymmetry using ultra-cold neutrons. These detectors provide an inexpensive alternative to more conventional scintillation detectors for large area cosmic ray anticoincidence detectors.

  19. Cosmic Rays and Extensive Air Showers

    CERN Document Server

    Stanev, Todor

    2010-01-01

    We begin with a brief introduction of the cosmic ray energy spectrum and its main features. At energies higher than 105 GeV cosmic rays are detected by the showers they initiate in the atmosphere. We continues with a brief description of the energy spectrum and composition derived from air shower data.

  20. Early history of cosmic rays at Chicago

    Science.gov (United States)

    Yodh, Gaurang B.

    2013-02-01

    Cosmic ray studies at the University of Chicago were started by Arthur Compton during the late 1920s. The high points of cosmic ray studies at Chicago under Compton and Marcel Schein are the focus of this report, which summarizes the research done at Chicago up to the end of World War II.

  1. Cosmic ray production curves below reworking zones

    International Nuclear Information System (INIS)

    Blanford, G.E.

    1980-01-01

    A method is presented for calculating cosmic ray production profiles below reworking zones. The method uses an input reworking depth determined from data such as signatures in the depth profile of ferromagnetic resonance intensity and input cosmic ray production profiles for an undisturbed surface. Reworking histories are simulated using Monte Carlo techniques, and depth profiles are used to determine cosmic ray exposure age limits with a specified probability. It is shown that the track density profiles predict cosmic ray exposure ages in lunar cores that are consistent with values determined by other methods. Results applied to neutron fluence and spallation rare gases eliminate the use of reworking depth as an adjustable parameter and give cosmic ray exposure ages that are compatible with each other

  2. Cosmic rays and the interstellar medium

    International Nuclear Information System (INIS)

    Wolfendale, A.W.

    1986-01-01

    It is inevitable that there is a close connection between cosmic rays and the ISM insofar as the propagation of cosmic rays is conditioned by the magnetic field in the ISM and the cosmic rays interact with the gas (and photon fluxes) in this medium. This paper deals with both topics. Propagation effects manifest themselves as an anisotropy in arrival directions and a review is given of anisotropy measurements and their interpretation. The status of studies of cosmic ray interactions is examined whit particular reference to the information about the ISM itself which comes from observations of the flux of secondary γ-rays produced by cosmic ray interactions with gas, the situation regarding molecular as in the Inner Galaxy being of particular concern

  3. Cosmic Ray Physics with ACORDE at LHC

    CERN Document Server

    Pagliarone, C.

    2008-01-01

    The use of large underground high-energy physics experiments, for comic ray studies, have been used, in the past, at CERN, in order to measure, precisely, the inclusive cosmic ray flux in the energy range from 2x10^10 - 2x10^12 eV. ACORDE, ALICE Cosmic Rays DEtector, will act as Level 0 cosmic ray trigger and, together with other ALICE apparatus, will provide precise information on cosmic rays with primary energies around 10^15 - 10^17 eV. This paper reviews the main detector features, the present status, commissioning and integration with other apparatus. Finally, we discuss the ACORDE-ALICE cosmic ray physics program.

  4. Cosmic ray physics with ACORDE at LHC

    International Nuclear Information System (INIS)

    Pagliarone, C; Fernandez-Tellez, A

    2008-01-01

    The use of large underground high-energy physics experiments, for comic ray studies, have been used, in the past, at CERN, in order to measure, precisely, the inclusive cosmic ray flux in the energy range from 2·10 10 to 2· 10 12 eV. ACORDE, ALICE Cosmic Rays DEtector, will act as Level 0 cosmic ray trigger and, together with other ALICE apparatus, will provide precise information on cosmic rays with primary energies around 10 15 to 10 17 eV. This paper reviews the main detector features, the present status, commissioning and integration with other apparatus. Finally, we discuss the ACORDE-ALICE cosmic ray physics program

  5. Cosmic ray physics with ACORDE at LHC

    Energy Technology Data Exchange (ETDEWEB)

    Pagliarone, C [Universita degli Studi di Cassino and INFN Pisa, Largo B. Pontecorvo, 3 - Pisa (Italy); Fernandez-Tellez, A [Benemerita Universidad Autonoma de Puebla (BUAP), Puebla (Mexico)], E-mail: pagliarone@fnal.gov

    2008-05-15

    The use of large underground high-energy physics experiments, for comic ray studies, have been used, in the past, at CERN, in order to measure, precisely, the inclusive cosmic ray flux in the energy range from 2{center_dot}10{sup 10} to 2{center_dot} 10{sup 12} eV. ACORDE, ALICE Cosmic Rays DEtector, will act as Level 0 cosmic ray trigger and, together with other ALICE apparatus, will provide precise information on cosmic rays with primary energies around 10{sup 15} to 10{sup 17} eV. This paper reviews the main detector features, the present status, commissioning and integration with other apparatus. Finally, we discuss the ACORDE-ALICE cosmic ray physics program.

  6. News Particle Physics: ATLAS unveils mural at CERN Prize: Corti Trust invites essay entries Astrophysics: CERN holds cosmic-ray conference Researchers in Residence: Lord Winston returns to school Music: ATLAS scientists record physics music Conference: Champagne flows at Reims event Competition: Students triumph at physics olympiad Teaching: Physics proves popular in Japanese schools Forthcoming Events

    Science.gov (United States)

    2011-01-01

    Particle Physics: ATLAS unveils mural at CERN Prize: Corti Trust invites essay entries Astrophysics: CERN holds cosmic-ray conference Researchers in Residence: Lord Winston returns to school Music: ATLAS scientists record physics music Conference: Champagne flows at Reims event Competition: Students triumph at physics olympiad Teaching: Physics proves popular in Japanese schools Forthcoming Events

  7. Pulsars as the sources of high energy cosmic ray positrons

    International Nuclear Information System (INIS)

    Hooper, Dan; Blasi, Pasquale; Serpico, Pasquale Dario

    2009-01-01

    Recent results from the PAMELA satellite indicate the presence of a large flux of positrons (relative to electrons) in the cosmic ray spectrum between approximately 10 and 100 GeV. As annihilating dark matter particles in many models are predicted to contribute to the cosmic ray positron spectrum in this energy range, a great deal of interest has resulted from this observation. Here, we consider pulsars (rapidly spinning, magnetized neutron stars) as an alternative source of this signal. After calculating the contribution to the cosmic ray positron and electron spectra from pulsars, we find that the spectrum observed by PAMELA could plausibly originate from such sources. In particular, a significant contribution is expected from the sum of all mature pulsars throughout the Milky Way, as well as from the most nearby mature pulsars (such as Geminga and B0656+14). The signal from nearby pulsars is expected to generate a small but significant dipole anisotropy in the cosmic ray electron spectrum, potentially providing a method by which the Fermi gamma-ray space telescope would be capable of discriminating between the pulsar and dark matter origins of the observed high energy positrons

  8. Muon Production in Relativistic Cosmic-Ray Interactions

    International Nuclear Information System (INIS)

    Klein, Spencer

    2009-01-01

    Cosmic-rays with energies up to 3 x 10 20 eV have been observed. The nuclear composition of these cosmic rays is unknown but if the incident nuclei are protons then the corresponding center of mass energy is √s nn = 700 TeV. High energy muons can be used to probe the composition of these incident nuclei. The energy spectra of high-energy (> 1 TeV) cosmic ray induced muons have been measured with deep underground or under-ice detectors. These muons come from pion and kaon decays and from charm production in the atmosphere. Terrestrial experiments are most sensitive to far-forward muons so the production rates aresensitive to high-x partons in the incident nucleus and low-x partons in the nitrogen/oxygen targets. Muon measurements can complement the central-particle data collected at colliders. This paper will review muon production data and discuss some non-perturbative (soft) models that have been used to interpret the data. I will show measurements of TeV muon transverse momentum (p T ) spectra in cosmic-ray air showers from MACRO, and describe how the IceCube neutrino observatory and the proposed Km3Net detector will extend these measurements to a higher p T region where perturbative QCD should apply. With a 1 km 2 surface area, the full IceCube detector should observe hundreds of muons/year with p T in the pQCD regime.

  9. Signs of cosmic rays in gravitational wave detectors

    International Nuclear Information System (INIS)

    Tavares, Denis Borgarelli

    2010-01-01

    One of the phenomena predicted by Einstein in the derivation of general relativity is the existence of small perturbations of the metric that he named gravitational waves. As they travel through space oscillates the space-time according to its polarization. This is the only major prediction of general relativity not yet proven completely. The small signal generated by the passage of a gravitational wave compared to the noise in the system of detection makes their direct detection one challenge of modern science. In this paper we study the noise generated by cosmic rays in the gravitational antenna Mario Schenberg, located in the city of Sao Paulo. Single muons and hadrons flux measurements held in the northern hemisphere were used to calculate the expected flux of these particles in the city of Sao Paulo. The calculation of the energy deposited in the detector of gravitational waves from cosmic rays was performed by Monte Carlo simulations using Geant4. The transport of muons and protons, with several energy and some different angles of incidence, across the building and the resonant sphere was simulated. We developed a thermo-acoustic model, called multi-point, suitable for calculating the energy deposited in the normal modes from the energy deposited on the sphere by elementary particles. With these results we calculate the expected rate of cosmic ray signals in the main detection mode of gravitational waves, nl = 12, of the Mario Schenberg detector, for temperatures T noise between 10 -5 and 10 -7 K. The results showed for the designed for 4.2 K sensitivity of the Mario Schenberg detector that the rate of signals due to cosmic rays is very small, being around 5 events per day. However, when it will reach the quantum limit will be needed a more detailed analysis of the antenna signal output, since the expected number of cosmic ray noise increases considerably, reaching about 250 signals per day. (author)

  10. UHE Cosmic Ray Observations Using the Cygnus Water - Array

    Science.gov (United States)

    Dion, Cynthia L.

    1995-01-01

    The CYGNUS water-Cerenkov array, consisting of five surface water-Cerenkov detectors, was built in the CYGNUS extensive air shower array at Los Alamos, New Mexico (latitude 36^circ N, longitude 107^circ W, altitude 2310 meters) to search for point sources of ultra-high energy particles (>1014 eV per particle) with the CYGNUS extensive air shower array. The water-Cerenkov detectors are used to improve the angular resolution of the extensive air shower array. This experiment searches for point sources of UHE gamma-radiation that may be of galactic or extra-galactic origin. The data set from December 1991 to January 1994 consists of data from both the water-Cerenkov array and the CYGNUS extensive air shower array. These data are combined, and the angular resolution of this combined data set is measured to be 0.34^circ+0.03 ^circ-0.04^circ. The measurement is made by observing the cosmic-ray shadowing of the Sun and the Moon. Using a subset of these data, three potential sources of UHE emission are studied: the Crab Pulsar, and the active galactic nuclei Markarian 421 and Markarian 501. A search is conducted for continuous emission from these three sources, and emission over shorter time scales. This experiment is particularly sensitive to emission over these shorter time scales. There is no evidence of UHE emission from these three sources over any time scales studied, and upper bounds to the flux of gamma radiation are determined. The flux upper limit for continuous emission from the Crab Pulsar is found to be 1.2times10^ {-13}/rm cm^2/s above 70 TeV. The flux upper limit for continuous emission from Markarian 421 is found to be 1.3times10^ {-13}/rm cm^2/s above 50 TeV. The flux upper limit for continuous emission from Markarian 501 is found to be 3.8times10^ {-13}/rm cm^2/s above 50 TeV.

  11. Cosmic ray studies on the ISS using SSNTD, BRADOS projects, 2001–2003

    CERN Document Server

    Pálfalvia, J K; Akatov, Y; Sajó-Bohus, L; Eördögh, I

    2005-01-01

    The BRADOS 1–3 projects were organised by the Russian Space Agency (RZA) between 2001 and 2003. The aim was to study the contribution of the primary galactic cosmic rays and of the secondary particles to the dose received by the crew of the International Space Station (ISS). Several laboratories participated in these experiments. Two different stacks (constructed by the team of the Atomic Energy Research Institute, AERI, Budapest, Hungary) composed of solid-state nuclear track detectors (SSNTD) were exposed inside the Service Module at different locations. The calibrations were made at the CERN high-energy neutron reference field named CERF (Geneva, Swiss). Applying a multiple track etching technique (2–20 h etching time) and a sophisticated image analyser, the secondary neutron dose was deduced. The composition of stacks, the evaluation methods and the results will be presented here or referenced to previous papers.

  12. Future Extensive Air Shower arrays: From Gamma-Ray Astronomy to Cosmic Rays

    Directory of Open Access Journals (Sweden)

    Sciascio Giuseppe Di

    2016-01-01

    Full Text Available Despite large progresses in building new detectors and in the analysis techniques, the key questions concerning the origin, acceleration and propagation of Galactic Cosmic Rays are still open. A number of new EAS arrays is in progress. The most ambitious and sensitive project between them is LHAASO, a new generation multi-component experiment to be installed at very high altitude in China (Daocheng, Sichuan province, 4400 m a.s.l.. The experiment will face the open problems through a combined study of photon- and charged particle-induced extensive air showers in the wide energy range 1011 – 1018 eV. In this paper the status of the experiment will be summarized, the science program presented and the outlook discussed in comparison with leading new projects.

  13. Solar /flare/ cosmic ray proton fluxes in the recent past

    International Nuclear Information System (INIS)

    Venkatesan, T.R.; Nautiyal, C.M.; Padia, J.T.; Rao, M.N.

    1980-01-01

    A method for determining the average solar cosmic ray (SCR) proton fluxes which occurred in the last few million yr from He-3 samples from suitable lunar rocks is presented. Specimens removed from 0.3-1.5, 5-7, and 7-9 mm depths of the lunar surface were cleaned to reveal the feldspar grains of interest and heated for stepwise mass-spectrometric analyses. The 200 micron or greater grains were outgassed at 600, 1000, 1200, and 1600 C and noble gas data were recorded, along with isotopic ratio data. He-3 is assumed to have been degassed completely from rocks shocked by an impact event and diffusion losses are negligible due to the 90 C or less temperature exposures on the lunar surface. Thus the presence of He-3 is indicative of cosmic ray incidence, and known galactic cosmic ray production abundances for He-3 can be subtracted from the total He-3 observed, yielding the SCR flux results, which, when combined with exposure data, yield a history of SCR events

  14. Shocked molecular gas and the origin of cosmic rays

    Science.gov (United States)

    Reach, William; Gusdorf, Antoine; Richter, Matthew

    2018-06-01

    When massive stars reach the end of their ability to remain stable with core nuclear fusion, they explode in supernovae that drive powerful shocks into their surroundings. Because massive stars form in and remain close to molecular clouds they often drive shocks into dense gas, which is now believed to be the origin of a significant fraction of galactic cosmic rays. The nature of the supernova-molecular cloud interaction is not well understood, though observations are gradually elucidating their nature. The range of interstellar densities, and the inclusion of circumstellar matter from the late-phase mass-loss of the stars before their explosions, leads to a wide range of possible appearances and outcomes. In particular, it is not even clear what speed or physical type of shocks are present: are they dense, magnetically-mediated shocks where H2 is not dissociated, or are they faster shocks that dissociate molecules and destroy some of the grains? SOFIA is observing some of the most significant (in terms of cosmic ray production potential and infrared energy output) supernova-molecular cloud interactions for measurement of the line widths of key molecular shocks tracers: H2, [OI], and CO. The presence of gas at speeds 100 km/s or greater would indicate dissociative shocks, while speeds 30 km/s and slower retain most molecules. The shock velocity is a key ingredient in modeling the interaction between supernovae and molecular clouds including the potential for formation of cosmic rays.

  15. Exploring the cosmic rays energy frontier with the Auger Observatory

    CERN Document Server

    CERN. Geneva

    2006-01-01

    The existence of cosmic rays with energies in excess of 1020 eV represents a longstanding scientific mystery. Unveileing the mechanism and source of production/acceleration of particles of such enormous energies is a challenging experimental task due to their minute flux, roughly one km2 century. The Pierre Auger Observatory, now nearing completion in Malargue, Mendoza Province, Argentina, is spread over an area of 3000 km2. Two techniques are employed to observe the cosmic ray showers: detection of the shower particles on the ground and detection of fluorescence light produced as the shower particles pass through the atmosphere. I will describe the status of the Observatory and its detectors, and early results from the data recorded while the observatory is reaching its completion.Organiser(s): L. Alvarez-Gaume / PH-THNote: * Tea & coffee will be served at 16:00.

  16. Design and construction of a uniform magnetic field generator for a 32 channel cosmic ray detector

    Science.gov (United States)

    Herrera-Guzman, K. N.; Gutierrez-Sanchez, R. A.; Felix, J.; Arceo, L. J.; Araujo, C.

    2017-10-01

    The trajectory of a particle can be measured if some points of its track are known. This is applied to any kind of particle, including cosmic rays. We have designed and built a device for this purpose. We present the design, construction and characterization of a uniform magnetic field generator system in a finite volume. An array of Cerenkov detectors will be placed inside of it for determining the cosmic rays charge and to reconstruct their trajectories.

  17. A cocoon of freshly accelerated cosmic rays detected by Fermi in the Cygnus Superbubble

    International Nuclear Information System (INIS)

    Ackermann, M.; Ajello, A.; Allafort, A.; Berenji, B.; Blandford, R.D.; Bloom, E.D.; Borgland, A.W.; Bottacini, E.; Buehler, R.; Cameron, R.A.; Chiang, J.; Claus, R.; Do Couto e Silva, E.; Drell, P.S.; Focke, W.B.; Glanzman, T.; Godfrey, G.; Hayashida, M.; Johnson, A.S.; Kamae, T.; Kerr, M.; Lande, J.; Michelson, P.F.; Mitthumsiri, W.; Monzani, M.E.; Moskalenko, I.V.; Murgia, S.; Nolan, P.L.; Okumura, A.; Orlando, E.; Paneque, D.; Prokhorov, D.; Tanaka, T.; Thayer, J.G.; Thayer, J.B.; Tramacere, A.; Uchiyama, Y.; Vandenbroucke, J.; Vianello, G.; Waite, A.P.; Wang, P.; Baldini, L.; Bellazzini, R.; Kuss, M.; Latronico, L.; Pesce-Rollins, M.; Razzano, M.; Sgro, C.; Ballet, J.; Casandjian, J.M.; Grenier, I.A.; Naumann-Godo, M.; Pierbattista, M.; Tibaldo, L.

    2011-01-01

    The origin of Galactic cosmic rays is a century-long puzzle. Indirect evidence points to their acceleration by supernova shock waves, but we know little of their escape from the shock and their evolution through the turbulent medium surrounding massive stars. Gamma rays can probe their spreading through the ambient gas and radiation fields. The Fermi Large Area Telescope (LAT) has observed the star-forming region of Cygnus X. The 1- to 100-giga-electron-volt images reveal a 50-parsec-wide cocoon of freshly accelerated cosmic rays that flood the cavities carved by the stellar winds and ionization fronts from young stellar clusters. It provides an example to study the youth of cosmic rays in a superbubble environment before they merge into the older Galactic population. (authors)

  18. A climatological study of the relations among solar activity, galactic ...

    Indian Academy of Sciences (India)

    activity, galactic cosmic ray and precipitation on various regions .... mate variations to cosmic rays and the physical- chemical .... For the wavelet spectrum, significance level for each ..... monthly climate for Europe and the globe: The observed.

  19. Ultrahigh energy cosmic ray fluxes and cosmogenic neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Stanev, Todor

    2013-04-15

    We discuss the possible origin of the two neutrino shower events reported by the IceCube Collaboration at the Neutrino 2012 conference in Kyoto, Japan. The suspicion early on was that these two events are due to cosmogenic neutrinos and possibly by electron antineutrinos generating the Glashow resonance. The difference of the energy of the W{sup −} in the resonance and the energy estimates of the detected cascade events makes this assumption unlikely. The conclusion then may be that these high energy neutrinos are produced at sources of high energy cosmic rays such as Active Galactic Nuclei.

  20. Cosmic ray modulation and radiation dose of aircrews during the solar cycle 24/25

    Science.gov (United States)

    Miyake, Shoko; Kataoka, Ryuho; Sato, Tatsuhiko

    2017-04-01

    Weak solar activity and high cosmic ray flux during the coming solar cycle are qualitatively anticipated by the recent observations that show the decline in the solar activity levels. We predict the cosmic ray modulation and resultant radiation exposure at flight altitude by using the time-dependent and three-dimensional model of the cosmic ray modulation. Our galactic cosmic ray (GCR) model is based on the variations of the solar wind speed, the strength of the heliospheric magnetic field, and the tilt angle of the heliospheric current sheet. We reproduce the 22 year variation of the cosmic ray modulation from 1980 to 2015 taking into account the gradient-curvature drift motion of GCRs. The energy spectra of GCR protons obtained by our model show good agreement with the observations by the Balloon-borne Experiment with a Superconducting magnetic rigidity Spectrometer (BESS) and the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) except for a discrepancy at the solar maximum. Five-year annual radiation dose around the solar minimum at the solar cycle 24/25 will be approximately 19% higher than that in the last cycle. This is caused by the charge sign dependence of the cosmic ray modulation, such as the flattop profiles in a positive polarity.

  1. High energy cosmic rays: sources and fluxes

    Energy Technology Data Exchange (ETDEWEB)

    Stanev, Todor; Gaisser, Thomas K.; Tilav, Serap

    2014-04-01

    We discuss the production of a unique energy spectrum of the high energy cosmic rays detected with air showers by shifting the energy estimates of different detectors. After such a spectrum is generated we fit the spectrum with three or four populations of cosmic rays that might be accelerated at different cosmic ray sources. We also present the chemical composition that the fits of the spectrum generates and discuss some new data sets presented this summer at the ICRC in Rio de Janeiro that may require new global fits.

  2. High-energy cosmic-ray acceleration

    CERN Document Server

    Bustamante, M; de Paula, W; Duarte Chavez, J A; Gago, A M; Hakobyan, H; Jez, P; Monroy Montañez, J A; Ortiz Velasquez, A; Padilla Cabal, F; Pino Rozas, M; Rodriguez Patarroyo, D J; Romeo, G L; Saldaña-Salazar , U J; Velasquez, M; von Steinkirch, M

    2010-01-01

    We briefly review the basics of ultrahigh-energy cosmic-ray acceleration. The Hillas criterion is introduced as a geometrical criterion that must be fulfilled by potential acceleration sites, and energy losses are taken into account in order to obtain a more realistic scenario. The different available acceleration mechanisms are presented, with special emphasis on Fermi shock acceleration and its prediction of a power-law cosmic-ray energy spectrum. We conclude that first-order Fermi acceleration, though not entirely satisfactory, is the most promising mechanism for explaining the ultra-high-energy cosmic-ray flux.

  3. RECORD-SETTING COSMIC-RAY INTENSITIES IN 2009 AND 2010

    International Nuclear Information System (INIS)

    Mewaldt, R. A.; Davis, A. J.; Leske, R. A.; Stone, E. C.; Cummings, A. C.; Labrador, A. W.; Lave, K. A.; Binns, W. R.; Israel, M. H.; Wiedenbeck, M. E.; Christian, E. R.; De Nolfo, G. A.; Von Rosenvinge, T. T.

    2010-01-01

    We report measurements of record-setting intensities of cosmic-ray nuclei from C to Fe, made with the Cosmic Ray Isotope Spectrometer carried on the Advanced Composition Explorer in orbit about the inner Sun-Earth Lagrangian point. In the energy interval from ∼70 to ∼450 MeV nucleon -1 , near the peak in the near-Earth cosmic-ray spectrum, the measured intensities of major species from C to Fe were each 20%-26% greater in late 2009 than in the 1997-1998 minimum and previous solar minima of the space age (1957-1997). The elevated intensities reported here and also at neutron monitor energies were undoubtedly due to several unusual aspects of the solar cycle 23/24 minimum, including record-low interplanetary magnetic field (IMF) intensities, an extended period of reduced IMF turbulence, reduced solar-wind dynamic pressure, and extremely low solar activity during an extended solar minimum. The estimated parallel diffusion coefficient for cosmic-ray transport based on measured solar-wind properties was 44% greater in 2009 than in the 1997-1998 solar-minimum period. In addition, the weaker IMF should result in higher cosmic-ray drift velocities. Cosmic-ray intensity variations at 1 AU are found to lag IMF variations by 2-3 solar rotations, indicating that significant solar modulation occurs inside ∼20 AU, consistent with earlier galactic cosmic-ray radial-gradient measurements. In 2010, the intensities suddenly decreased to 1997 levels following increases in solar activity and in the inclination of the heliospheric current sheet. We describe the conditions that gave cosmic rays greater access to the inner solar system and discuss some of their implications.

  4. A Cosmic Ray Telescope For Educational Purposes

    International Nuclear Information System (INIS)

    Voulgaris, G.; Kazanas, S.; Chamilothoris, I.

    2010-01-01

    Cosmic ray detectors are widely used, for educational purposes, in order to motivate students to the physics of elementary particles and astrophysics. Using a 'telescope' of scintillation counters, the directional characteristics, diurnal variation, correlation with solar activity, can be determined, and conclusions about the composition, origin and interaction of elementary particles with the magnetic field of earth can be inferred. A telescope was built from two rectangular scintillator panels with dimensions: 91.6x1.9x3.7 cm 3 . The scintillators are placed on top of each other, separated by a fixed distance of 34.6 cm. They are supported by a wooden frame which can be rotated around a horizontal axis. Direction is determined by the coincidence of the signals of the two PMTs. Standard NIM modules are used for readout. This device is to be used in the undergraduate nuclear and particle physics laboratory. The design and construction of the telescope as well as some preliminary results are presented.

  5. Imprints to the terrestrial environment at galactic arm crossings of the solar system

    Science.gov (United States)

    Fahr, H. J.; Fichtner, H.; Scherer, K.; Stawicki, O.

    At its itinerary through our milky way galaxy the solar system moves through highly variable interstellar environments. Due to its orbital revolution around the galactic center, the solar system also crosses periodically the spiral arms of our galactic plane and thereby expe riences pronounced enviromental changes. Gas densities, magnetic fields and galactic cosmic ray intensities are substantially higher there compared to interarm conditions. Here we present theoretical calculations describing the SN-averaged galactic cosmic ray spectrum for regions inside and outside of galactic arms which then allow to predict how periodic passages of the solar system through galactic arms should be reflected by enhanced particle irradiations of the earth`s atmosphere and by correlated terrestrial Be-10 production rates.

  6. Composition of cosmic rays in the knee region of the primary energy spectrum

    International Nuclear Information System (INIS)

    Das Gupta, U.

    1989-01-01

    The Soudan Surface-Underground Cosmic Ray Telescope is located at the Soudan iron mine in northern Minnesota. It consists of a coincidence arrangement of two detectors-one installed at the surface of the mine and the other located underground, at a vertical depth of 600 meters. Using such an arrangement, the energy and composition of a primary cosmic ray particle can be determined independently of one another. When a high energy cosmic ray enters the Earth's atmosphere, secondary particles are produced in successive interactions, creating an extensive air shower. Using the surface detector, the number of particles in the shower at the surface of the Earth can be counted and the energy of the primary particle estimated. Of all the particles that are created in a cosmic ray air shower, only the energetic muons are able to penetrate underground. The separations of the muons below ground are measured by the Soudan 1 detector and this serves as an indicator of the type of nucleus that initiated the shower. The Soudan surface-underground detector is sensitive to primary cosmic rays of energies between 10 14 and 10 18 eV. The data from the experiment were compared to the predictions of various cosmic ray composition models, within this energy range. The data supported a composition model that was proton dominated up to the highest energies measured. There was no indication of a shift in the composition towards heavier primaries as would be expected on the basis of some models

  7. Shell-type SNRs as sources of cosmic rays

    Science.gov (United States)

    Sinitsyna, V. G.; Andreeva, M. S.; Balygin, K. A.; Borisov, S. S.; Ivanov, I. A.; Kirichenko, A. M.; Klimov, A. I.; Kozhukhova, I. P.; Mirzafatikhov, R. M.; Moseiko, N. I.; Ostashev, I. E.; Palamarchuk, A. I.; Sinitsyna, V. Y.; Volokh, I. G.

    2017-06-01

    Investigations of VHE gamma-ray sources by any methods, including mirror Cherenkov telescopes, touch on the problem of the cosmic ray origin and, accordingly, the role of the Galaxy in their generation. SHALON observations have yielded results on Galactic supernova remnants (SNR) of different ages. Among them are: the shell-type SNRs Tycho's SNR (1572y), Cas A (1680y), IC 443 (age ˜ (3 ÷ 30) × 103 y), Cygni SNR (age ˜ (5 ÷ 7) × 103 y), G166.0 + 4.3 (age ˜ 24 × 103 y) and the classical nova GK Per (Nova 1901). Observation results are presented for each of the SNRs with spectral energy distributions by SHALON in comparison with other experiment data and images by SHALON together with data from X-rays by Chandra and radio-data by CGPS. The collected experimental data have confirmed the prediction of the theory about the hadronic generation mechanism of very high energy 800 GeV-100 TeV gamma-rays in Tycho's SNR, Cas A and IC443. For the first time, unique data on GK Per (Nova1901) TeV gamma-ray emission were obtained with the SHALON experiment. The X-ray data shows that the nova remnant of GK Per could be a younger remnant that will resemble older SNRs like IC 443 which interact with molecular clouds. GK Per is supposed to be a candidate for TeV gamma-ray emission due to accelerated particles in the reverse shock region.

  8. A theory of Cosmic Rays

    CERN Document Server

    Dar, Arnon; Dar, Arnon; Rújula, Alvaro De

    2008-01-01

    We present a theory of non-solar cosmic rays (CRs) based on a single type of CR source at all energies. The total luminosity of the Galaxy, the broken power-law spectra with their observed slopes, the position of the `knee(s)' and `ankle', and the CR composition and its variation with energy are all predicted in terms of very simple and completely `standard' physics. The source of CRs is extremely `economical': it has only one parameter to be fitted to the ensemble of all of the mentioned data. All other inputs are `priors', that is, theoretical or observational items of information independent of the properties of the source of CRs, and chosen to lie in their pre-established ranges. The theory is part of a `unified view of high-energy astrophysics' --based on the `Cannonball' model of the relativistic ejecta of accreting black holes and neutron stars. If correct, this model is only lacking a satisfactory theoretical understanding of the `cannon' that emits the cannonballs in catastrophic processes of accreti...

  9. Cosmic Ray and Tev Gamma Ray Generation by Quasar Remnants

    Science.gov (United States)

    Boldt, Elihu; Loewenstein, Michael; White, Nicholas E. (Technical Monitor)

    2000-01-01

    Results from new broadband (radio to X-ray) high-resolution imaging studies of the dormant quasar remnant cores of nearby giant elliptical galaxies are now shown to permit the harboring of compact dynamos capable of generating the highest energy cosmic ray particles and associated curvature radiation of TeV photons. Confirmation would imply a global inflow of interstellar gas all the way to the accretion powered supermassive black hole at the center of the host galaxy.

  10. ULTRAHIGH ENERGY COSMIC RAYS: REVIEW OF THE CURRENT SITUATION

    Directory of Open Access Journals (Sweden)

    Todor Stanev

    2013-12-01

    Full Text Available We describe the current situation of the data on the highest energy particles in the Universe – the ultrahigh energy cosmic rays. The new results in the field come from the Telescope Array experiment in Utah, U.S.A. For this reason we concentrate on the results from these experiments and compare them to the measurements of the other two recent experiments, the High Resolution Fly’sEye and the Southern Auger Observatory.

  11. Probing cosmic-ray acceleration and propagation with H{sub 3}{sup +} observations

    Energy Technology Data Exchange (ETDEWEB)

    Indriolo, Nick; Fields, Brian D.; McCall, Benjamin J. [3D University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States)

    2015-01-22

    As cosmic rays traverse the interstellar medium (ISM) they interact with the ambient gas in various ways. These include ionization of atoms and molecules, spallation of nuclei, excitation of nuclear states, and production of pions among others. All of these interactions produce potential observables which may be used to trace the flux of cosmic rays. One such observable is the molecular ion H{sub 3}{sup +}-produced via the ionization of an H{sub 2} molecule and its subsequent collision with another H{sub 2}-which can be identified by absorption lines in the 3.5-4 μm spectral region. We have detected H{sub 3}{sup +} in several Galactic diffuse cloud sight lines and used the derived column densities to infer ζ{sub 2}, the cosmic-ray ionization rate of H{sub 2}. Ionization rates determined in this way vary from about 7×10{sup −17} s{sup −1} to about 8×10{sup −16} s{sup −1}, and suggest the possibility of discrete sources producing high local fluxes of low-energy cosmic rays. Theoretical calculations of the ionization rate from postulated cosmic-ray spectra also support this possibility. Our recent observations of H{sub 3}{sup +} near the supernova remnant IC 443 (a likely site of cosmic-ray acceleration) point to even higher ionization rates, on the order of 10{sup −15} s{sup −1}. Together, all of these results can further our understanding of the cosmic-ray spectrum both near the acceleration source and in the general Galactic ISM.

  12. Lightning Discharges, Cosmic Rays and Climate

    Science.gov (United States)

    Kumar, Sanjay; Siingh, Devendraa; Singh, R. P.; Singh, A. K.; Kamra, A. K.

    2018-03-01

    The entirety of the Earth's climate system is continuously bombarded by cosmic rays and exhibits about 2000 thunderstorms active at any time of the day all over the globe. Any linkage among these vast systems should have global consequences. Numerous studies done in the past deal with partial links between some selected aspects of this grand linkage. Results of these studies vary from weakly to strongly significant and are not yet complete enough to justify the physical mechanism proposed to explain such links. This review is aimed at presenting the current understanding, based on the past studies on the link between cosmic ray, lightning and climate. The deficiencies in some proposed links are pointed out. Impacts of cosmic rays on engineering systems and the possible effects of cosmic rays on human health are also briefly discussed. Also enumerated are some problems for future work which may help in developing the grand linkage among these three vast systems.

  13. COSMIC-RAY TRANSPORT AND ANISOTROPIES

    Energy Technology Data Exchange (ETDEWEB)

    Biermann, Peter L. [MPI for Radioastronomy, Auf dem Huegel 69, D-53121 Bonn (Germany); Becker Tjus, Julia; Mandelartz, Matthias [Ruhr-Universitaet Bochum, Fakultaet fuer Physik and Astronomie, Theoretische Physik I, D-44780 Bochum (Germany); Seo, Eun-Suk [Department of Physics, University of Maryland, College Park, MD 20742 (United States)

    2013-05-10

    We show that the large-scale cosmic-ray anisotropy at {approx}10 TeV can be explained by a modified Compton-Getting effect in the magnetized flow field of old supernova remnants. Cosmic rays arrive isotropically to the flow field and are then carried along with the flow to produce a large-scale anisotropy in the arrival direction. This approach suggests an optimum energy scale for detecting the anisotropy. Two key assumptions are that propagation is based on turbulence following a Kolmogorov law and that cosmic-ray interactions are dominated by transport via cosmic-ray-excited magnetic irregularities through the stellar wind of an exploding star and its shock shell. A prediction is that the amplitude is smaller at lower energies due to incomplete sampling of the velocity field and also smaller at larger energies due to smearing.

  14. Cosmic ray antimatter and baryon symmetric cosmology

    Science.gov (United States)

    Stecker, F. W.; Protheroe, R. J.; Kazanas, D.

    1982-01-01

    The relative merits and difficulties of the primary and secondary origin hypotheses for the observed cosmic-ray antiprotons, including the new low-energy measurement of Buffington, et al. We conclude that the cosmic-ray antiproton data may be evidence for antimatter galaxies and baryon symmetric cosmology. The present bar P data are consistent with a primary extragalactic component having /p=/equiv 1+/- 3.2/0.7x10 = to the -4 independent of energy. We propose that the primary extragalactic cosmic ray antiprotons are most likely from active galaxies and that expected disintegration of bar alpha/alpha ban alpha/alpha. We further predict a value for ban alpha/alpha =/equiv 10 to the -5, within range of future cosmic ray detectors.

  15. Correlation of the highest-energy cosmic rays with nearby extragalactic objects

    NARCIS (Netherlands)

    Pierre Auger Collaboration, [No Value; Abraham, J.; Abreu, P.; Aglietta, M.; Aguirre, C.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Alvarez, C.; Alvarez-Muñiz, J.; Ambrosio, M.; Anchordoqui, L.; Andringa, S.; Anzalone, A.; Aramo, C.; Argirò, S.; Arisaka, K.; Armengaud, E.; Arneodo, F.; Arqueros, F.; Asch, T.; Asorey, H.; Assis, P.; Atulugama, B. S.; Aublin, J.; Ave, M.; Avila, G.; Bäcker, T.; Badagnani, D.; Barbosa, A. F.; Barnhill, D.; Barroso, S. L. C.; Bauleo, P.; Beatty, J.; Beau, T.; Becker, B. R.; Becker, K. H.; Bellido, J. A.; BenZvi, S.; Berat, C.; Bergmann, T.; Bernardini, P.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanch-Bigas, O.; Blanco, F.; Blasi, P.; Bleve, C.; Blümer, H.; Bohácová, M.; Bonifazi, C.; Bonino, R.; Boratav, M.; Brack, J.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Busca, N. G.; Caballero-Mora, K. S.; Cai, B.; Camin, D. V.; Caruso, R.; Carvalho, W.; Castellina, A.; Catalano, O.; Cataldi, G.; Cazón-Boado, L.; Cester, R.; Chauvin, J.; Chiavassa, A.; Chinellato, J. A.; Chou, A.; Chye, J.; Clark, P. D. J.; Clay, R. W.; Colombo, E.; Conceição, R.; Connolly, B.; Contreras, F.; Coppens, J.; Cordier, A.; Cotti, U.; Coutu, S.; Covault, C. E.; Creusot, A.; Cronin, J.; Dagoret-Campagne, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Donato, C.; de Jong, S. J.; De La Vega, G.; de Mello Junior, W. J. M.; de Mello Neto, J. R. T.; De Mitri, I.; de Souza, V.; del Peral, L.; Deligny, O.; Della Selva, A.; Delle Fratte, C.; Dembinski, H.; Di Giulio, C.; Diaz, J. C.; Dobrigkeit, C.; D'Olivo, J. C.; Dornic, D.; Dorofeev, A.; dos Anjos, J. C.; Dova, M. T.; D'Urso, D.; DuVernois, M. A.; Engel, R.; Epele, L.; Erdmann, M.; Escobar, C. O.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Fernández, A.; Ferrer, F.; Ferry, S.; Fick, B.; Filevich, A.; Filipcic, A.; Fleck, I.; Fonte, R.; Fracchiolla, C. E.; Fulgione, W.; García, B.; García Gámez, D.; Garcia-Pinto, D.; Garrido, X.; Geenen, H.; Gelmini, G.; Gemmeke, H.; Ghia, P. L.; Giller, M.; Glass, H.; Gold, M. S.; Golup, G.; Gomez Albarracin, F.; Gómez Berisso, M.; Gómez Herrero, R.; Gonçalves, P.; Gonçalves do Amaral, M.; Gonzalez, D.; Gonzalez, J. G.; González, M.; Góra, D.; Gorgi, A.; Gouffon, P.; Grassi, V.; Grillo, A.; Grunfeld, C.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Gutiérrez, J.; Hague, J. D.; Hamilton, J. C.; Hansen, P.; Harari, D.; Harmsma, S.; Harton, J. L.; Haungs, A.; Hauschildt, T.; Healy, M. D.; Hebbeker, T.; Heck, D.; Hojvat, C.; Holmes, V. C.; Homola, P.; Hörandel, J.; Horneffer, A.; Horvat, M.; Hrabovsky, M.; Huege, T.; Iarlori, M.; Insolia, A.; Ionita, F.; Italiano, A.; Kaducak, M.; Kampert, K. H.; Keilhauer, B.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapik, R.; Knapp, J.; Koang, D.-H.; Kopmann, A.; Krieger, A.; Krömer, O.; Kümpel, D.; Kunka, N.; Kusenko, A.; La Rosa, G.; Lachaud, C.; Lago, B. L.; Lebrun, D.; Le Brun, P.; Lee, J.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Leuthold, M.; Lhenry-Yvon, I.; López, R.; Lopez Agüera, A.; Lozano Bahilo, J.; Maccarone, M. C.; Macolino, C.; Maldera, S.; Malek, M.; Mancarella, G.; Manceñido, M. E.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Maris, I. C.; Martello, D.; Martínez, J.; Martínez Bravo, O.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurizio, D.; Mazur, P. O.; McCauley, T.; McEwen, M.; McNeil, R. R.; Medina, M. C.; Medina-Tanco, G.; Meli, A.; Melo, D.; Menichetti, E.; Menschikov, A.; Meurer, Chr.; Meyhandan, R.; Micheletti, M. I.; Miele, G.; Miller, W.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morales, B.; Morello, C.; Moreno, E.; Moreno, J. C.; Morris, C.; Mostafá, M.; Muller, M. A.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Nellen, L.; Newman-Holmes, C.; Newton, D.; Nguyen Thi, T.; Nierstenhöfer, N.; Nitz, D.; Nosek, D.; Nozka, L.; Oehlschläger, J.; Ohnuki, T.; Olinto, A.; Olmos-Gilbaja, V. M.; Ortiz, M.; Ostapchenko, S.; Otero, L.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Parente, G.; Parizot, E.; Parlati, S.; Pastor, S.; Patel, M.; Paul, T.; Pavlidou, V.; Payet, K.; Pech, M.; Pçkala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Petrera, S.; Petrinca, P.; Petrov, Y.; Ngoc, DiepPham; Ngoc, DongPham; Pham Thi, T. N.; Pichel, A.; Piegaia, R.; Pierog, T.; Pimenta, M.; Pinto, T.; Pirronello, V.; Pisanti, O.; Platino, M.; Pochon, J.; Porter, T. A.; Privitera, P.; Prouza, M.; Quel, E. J.; Rautenberg, J.; Reucroft, S.; Revenu, B.; Rezende, F. A. S.; Rídky, J.; Riggi, S.; Risse, M.; Rivière, C.; Rizi, V.; Roberts, M.; Robledo, C.; Rodriguez, G.; Rodríguez Frías, D.; Rodriguez Martino, J.; Rodriguez Rojo, J.; Rodriguez-Cabo, I.; Ros, G.; Rosado, J.; Roth, M.; Rouillé-d'Orfeuil, B.; Roulet, E.; Rovero, A. C.; Salamida, F.; Salazar, H.; Salina, G.; Sánchez, F.; Santander, M.; Santo, C. E.; Santos, E. M.; Sarazin, F.; Sarkar, S.; Sato, R.; Scherini, V.; Schieler, H.; Schmidt, F.; Schmidt, T.; Scholten, O.; Schovánek, P.; Schüssler, F.; Sciutto, S. J.; Scuderi, M.; Segreto, A.; Semikoz, D.; Settimo, M.; Shellard, R. C.; Sidelnik, I.; Siffert, B. B.; Sigl, G.; Smetniansky De Grande, N.; Smialkowski, A.; Smída, R.; Smith, A. G. K.; Smith, B. E.; Snow, G. R.; Sokolsky, P.; Sommers, P.; Sorokin, J.; Spinka, H.; Squartini, R.; Strazzeri, E.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Takahashi, J.; Tamashiro, A.; Tamburro, A.; Tascau, O.; Tcaciuc, R.; Thomas, D.; Ticona, R.; Tiffenberg, J.; Timmermans, C.; Tkaczyk, W.; Todero Peixoto, C. J.; Tomé, B.; Tonachini, A.; Torresi, D.; Travnicek, P.; Tripathi, A.; Tristram, G.; Tscherniakhovski, D.; Tueros, M.; Tunnicliffe, V.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van den Berg, A. M.; van Elewyck, V.; Vázquez, R. A.; Veberic, D.; Veiga, A.; Velarde, A.; Venters, T.; Verzi, V.; Videla, M.; Villaseñor, L.; Vorobiov, S.; Voyvodic, L.; Wahlberg, H.; Wainberg, O.; Waldenmaier, T.; Walker, P.; Warner, D.; Watson, A. A.; Westerhoff, S.; Wieczorek, G.; Wiencke, L.; Wilczynska, B.; Wilczynski, H.; Wileman, C.; Winnick, M. G.; Wu, H.; Wundheiler, B.; Xu, J.; Yamamoto, T.; Younk, P.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zech, A.; Zepeda, A.; Ziolkowski, M.

    2007-01-01

    Using data collected at the Pierre Auger Observatory during the past 3.7 years, we demonstrated a correlation between the arrival directions of cosmic rays with energy above 6 × 1019 electron volts and the positions of active galactic nuclei (AGN) lying within ~75 megaparsecs. We rejected the

  16. Fornax A, Centaurus A other radio galaxies as sources of ultra-high energy cosmic rays

    Science.gov (United States)

    Matthews, J. H.; Bell, A. R.; Blundell, K. M.; Araudo, A. T.

    2018-06-01

    The origin of ultra-high energy cosmic rays (UHECRs) is still unknown. It has recently been proposed that UHECR anisotropies can be attributed to starburst galaxies or active galactic nuclei. We suggest that the latter is more likely and that giant-lobed radio galaxies such as Centaurus A and Fornax A can explain the data.

  17. CRaTER: The Cosmic Ray Telescope for the Effects of Radiation Experiment on the Lunar Reconnaissance Orbiter Mission

    OpenAIRE

    Spence, H. E.; Case, A. W.; Golightly, M. J.; Heine, T.; Larsen, B. A.; Blake, J. B.; Caranza, P.; Crain, W. R.; George, J.; Lalic, M.; Lin, A.; Looper, M. D.; Mazur, J. E.; Salvaggio, D.; Kasper, J. C.

    2009-01-01

    The Cosmic Ray Telescope for the Effects of Radiation (CRaTER) on the Lunar Reconnaissance Orbiter (LRO) characterizes the radiation environment to be experienced by humans during future lunar missions. CRaTER measures the effects of ionizing energy loss in matter due to penetrating solar energetic protons (SEP) and galactic cosmic rays (GCR), specifically in silicon solid-state detectors and after interactions with tissue-equivalent plastic (TEP), a synthetic analog of human tissue. The CRaT...

  18. Low cloud properties influenced by cosmic rays

    DEFF Research Database (Denmark)

    Marsh, Nigel; Svensmark, Henrik

    2000-01-01

    The influence of solar variability on climate is currently uncertain. Recent observations have indicated a possible mechanism via the influence of solar modulated cosmic rays on global cloud cover. Surprisingly the influence of solar variability is strongest in low clouds (less than or equal to3 km......), which points to a microphysical mechanism involving aerosol formation that is enhanced by ionization due to cosmic rays. If confirmed it suggests that the average state of the heliosphere is important for climate on Earth....

  19. ACORDE a cosmic ray detector for ALICE

    International Nuclear Information System (INIS)

    Fernandez, A.; Gamez, E.; Herrera, G.; Lopez, R.; Leon-Monzon, I.; Martinez, M.I.; Pagliarone, C.; Paic, G.; Roman, S.; Tejeda, G.; Vargas, M.A.; Vergara, S.; Villasenor, L.; Zepeda, A.

    2007-01-01

    ACORDE is one of the ALICE detectors, presently under construction at CERN. It consists of an array of plastic scintillator counters placed on the three upper faces of the ALICE magnet. It will act as a cosmic ray trigger, and, together with other ALICE sub-detectors, will provide precise information on cosmic rays with primary energies around 10 15 -10 17 eV. Here we describe the design of ACORDE along with the present status and integration into ALICE

  20. Sulphur mountain: Cosmic ray intensity records

    International Nuclear Information System (INIS)

    Venkatesan, D.; Mathews, T.

    1985-01-01

    This book deals with the comic ray intensity registrations at the Sulphur Mountain Cosmic Ray Laboratory. The time series of intensity form a valuable data-set, for studying cosmic ray intensity variations and their dependence on solar activity. The IGY neutron monitor started operating from July 1, 1957 and continued through 1963. Daily mean values are tabulated for the period and these are also represented in plots. This monitor was set up by the National Research Council of Canada

  1. High-energy cosmic-ray acceleration

    OpenAIRE

    Bustamante, M; Carrillo Montoya, G; de Paula, W; Duarte Chavez, J A; Gago, A M; Hakobyan, H; Jez, P; Monroy Montañez, J A; Ortiz Velasquez, A; Padilla Cabal, F; Pino Rozas, M; Rodriguez Patarroyo, D J; Romeo, G L; Saldaña-Salazar , U J; Velasquez, M

    2010-01-01

    We briefly review the basics of ultrahigh-energy cosmic-ray acceleration. The Hillas criterion is introduced as a geometrical criterion that must be fulfilled by potential acceleration sites, and energy losses are taken into account in order to obtain a more realistic scenario. The different available acceleration mechanisms are presented, with special emphasis on Fermi shock acceleration and its prediction of a power-law cosmic-ray energy spectrum. We conclude that first-order Fermi accelera...

  2. Nuclear collisions in measurements of the cosmic ray charge spectrum with a counter telescope

    International Nuclear Information System (INIS)

    Lindstam, S.

    1975-06-01

    The importance of nuclear collisions of cosmic ray particles in a counter detector telescope is studied by simple Monte Carlo techniques. The interest concentrates on the charge region just below iron and the calculations are restricted to fully relativistic cosmic rays. It is found that it is difficult to avoid a blurring in the charge spectrum from nuclear collisions leading to considerable systematic errors in some abundance ratios. (Auth.)

  3. Pair production from nuclear collisions and cosmic ray transport

    International Nuclear Information System (INIS)

    Norbury, John W

    2006-01-01

    Modern cosmic ray transport codes, that are capable of use for a variety of applications, need to include all significant atomic, nuclear and particle reactions at a variety of energies. Lepton pair production from nucleus-nucleus collisions has not been included in transport codes to date. Using the methods of Baur, Bertulani and Baron, the present report provides estimates of electron-positron pair production cross sections for nuclei and energies relevant to cosmic ray transport. It is shown that the cross sections are large compared to other typical processes such as single neutron removal due to strong or electromagnetic interactions. Therefore, lepton pair production may need to be included in some transport code applications involving MeV electrons. (brief report)

  4. Inverse Flux versus Pressure of Muons from Cosmic Rays

    Science.gov (United States)

    Buitrago, D.; Armendariz, R.

    2017-12-01

    When an incoming cosmic ray proton or atom collides with particles in earth's atmosphere a shower of secondary muons is created. Cosmic ray muon flux was measured at the Queensborough Community College using a QuarkNet detector consisting of three stacked scintillator muon counters and a three-fold coincidence trigger. Data was recorded during a three-day period during a severe weather storm that occurred from March 13-17, 2017. A computer program was created in Python to read the muon flux rate and atmospheric pressure sensor readings from the detector's data acquisition board. The program converts the data from hexadecimal to decimal, re-bins the data in a more suitable format, creates and overlays plots of muon flux with atmospheric pressure. Results thus far show a strong correlation between muon flux and atmospheric pressure. More data analysis will be done to verify the above conclusion.

  5. PAMELA mission: heralding a new era in cosmic ray physics

    Directory of Open Access Journals (Sweden)

    Ricciarini S. B.

    2014-04-01

    Full Text Available 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.

  6. The response of clouds and aerosols to cosmic ray decreases

    DEFF Research Database (Denmark)

    Svensmark, J.; Enghoff, Martin Andreas Bødker; Shaviv, N. J.

    2016-01-01

    A method is developed to rank Forbush Decreases (FDs) in the galactic cosmic ray radiation according to their expected impact on the ionization of the lower atmosphere. Then a Monte Carlo bootstrap based statistical test is formulated to estimate the significance of the apparent response in physi......A method is developed to rank Forbush Decreases (FDs) in the galactic cosmic ray radiation according to their expected impact on the ionization of the lower atmosphere. Then a Monte Carlo bootstrap based statistical test is formulated to estimate the significance of the apparent response...... in physical and micro-physical cloud parameters to FDs. The test is subsequently applied to one ground based and three satellite based datasets. Responses (> 95%) to FDs are found in the following parameters of the analyzed datasets. AERONET: Ångström exponent (cloud condensation nuclei changes), SSM...... with the strength of the FDs, and the signs and magnitudes of the responses agree with model based expectations. The effect is mainly seen in liquid clouds. An impact through changes in UV driven photo chemistry is shown to be negligible and an impact via UV absorption in the stratosphere is found to have no effect...

  7. How can we protect astronauts from cosmic rays?

    International Nuclear Information System (INIS)

    Parker, E.

    2006-01-01

    Interplanetary astronauts would absorb more radiation in a single year than radiation workers are supposed to receive in a lifetime and as a consequence large number of them would develop radiation-related illnesses like cancer, cataract or would suffer from brain damage. In recognition to radiation threats, Nasa set up the space radiation shielding program in 2003. The first idea was to protect the astronauts by surrounding them with matter, by analogy of the earth's atmosphere but the problem of such a shield is its weight: the required mass would be at least 400 tons. The second proposal was to deflect the cosmic rays magnetically but the deflection of particles that have energies up to 2 GeV requires a magnetic field 600.000 times as strong as earth's equatorial field. Strong magnetic field may itself be dangerous. A more recent idea has been to give the spacecraft a positive charge which would repel any incoming positively charged nucleus. The drawback is that the ship will attract and accelerate negatively charged particles over distances as long as a few tens of thousands of kilometers. The result would be that the natural cosmic-ray flux would be replaced with a much more intense artificial one. At the present time the different solutions for protecting the astronauts from cosmic rays give little encouragement. (A.C.)

  8. Determination of cosmic ray (CR) ionization path and iono/atmospheric cut-off energy from CR intervals III, IV and V in the planetary environments

    International Nuclear Information System (INIS)

    Velinov, P.

    2001-01-01

    In this paper are determined the ionization path and cut-off energies of the cosmic ray (CR) nuclei in relation to the general interaction model 'CR - ionosphere-middle atmosphere'. Here the ionization path and the iono/atmospheric cut-off energies of the galactic CR, solar CR and anomalous CR are separately considered in each energetic range, without taking into account the particle transfer from one range in another. This more general approach will be the object of a further paper

  9. Cosmic ray physics in space: the role of Sergey Vernov's scientific school

    Science.gov (United States)

    Panasyuk, M. I.

    2011-04-01

    Cosmic rays were discovered almost 100 years ago. Since then the scientific world has learned a lot from their nature: the particles nascent in the Universe, both in our Galaxy and outside, the basic mechanisms of their acceleration, transfer in the interstellar environment and the interaction of the primary cosmic rays with the atmosphere surrounding the Earth. Before 1957, i.e., the beginning of the Space Era, researchers' capabilities were limited to experiments performed on the ground, underground and in near-ground atmosphere to flight altitudes of aerostats, airplanes and rockets, i.e., where only secondary radiation is in existence, this is the result of the interaction of cosmic rays with the Earth's atmosphere. The launching of spacecraft allowed the scientists to commence exploring the Universe's primordial matter itself outside the atmosphere, i.e., the primary cosmic rays. Sergey Vernov, the Russian scientist, was among them.

  10. Development and data analysis of a radio-detection of ultra high energy cosmic rays experiment

    International Nuclear Information System (INIS)

    Belletoile, A.

    2007-10-01

    The radio-detection of cosmic rays was first attempted in the sixties. Unfortunately at that time, the results suffered from poor reproducibility and the technique was abandoned in favour of direct particle and fluorescence detection. Taking advantage of recent technological improvements the radio-detection of ultra high energy cosmic rays is being reinvestigated. In this document, first, we remind the reader of the global problematic of cosmic rays. Then, the several mechanisms involved in the emission of an electric field associated with extensive air showers are discussed. The CODALEMA (cosmic detection array with logarithmic electro magnetic antenna) experiment that aims to demonstrate the feasibility of cosmic ray radio-detection, is extensively described along with the first experimental results. A radio-detection test experiment implanted at the giant detector Pierre Auger is presented. It should provide inputs to design the future detector using this technique at extreme energies. (author)

  11. Cosmic ray spectrum, composition, and anisotropy measured with IceCube

    International Nuclear Information System (INIS)

    Tamburro, Alessio

    2014-01-01

    Analysis of cosmic ray surface data collected with the IceTop array of Cherenkov detectors at the South Pole provides an accurate measurement of the cosmic ray spectrum and its features in the “knee” region up to energies of about 1 EeV. IceTop is part of the IceCube Observatory that includes a deep-ice cubic kilometer detector that registers signals of penetrating muons and other particles. Surface and in-ice signals detected in coincidence provide clear insights into the nuclear composition of cosmic rays. IceCube already measured an increase of the average primary mass as a function of energy. We present preliminary results on both IceTop-only and coincident events analysis. Furthermore, we review the recent measurement of the cosmic ray anisotropy with IceCube

  12. Cosmic ray spectrum, composition, and anisotropy measured with IceCube

    Science.gov (United States)

    Tamburro, Alessio

    2014-04-01

    Analysis of cosmic ray surface data collected with the IceTop array of Cherenkov detectors at the South Pole provides an accurate measurement of the cosmic ray spectrum and its features in the "knee" region up to energies of about 1 EeV. IceTop is part of the IceCube Observatory that includes a deep-ice cubic kilometer detector that registers signals of penetrating muons and other particles. Surface and in-ice signals detected in coincidence provide clear insights into the nuclear composition of cosmic rays. IceCube already measured an increase of the average primary mass as a function of energy. We present preliminary results on both IceTop-only and coincident events analysis. Furthermore, we review the recent measurement of the cosmic ray anisotropy with IceCube.

  13. Observation of superheavy primary cosmic ray nuclei with solid state track detectors and x-ray films

    International Nuclear Information System (INIS)

    Doke, Tadayoshi; Hayashi, Takayoshi; Ito, Kensai; Yanagimachi, Tomoki; Kobayashi, Shigeru.

    1977-01-01

    The measurements of energy spectra and the nuclear charge distribution of superheavy nuclei heavier than iron in primary cosmic ray can provide information on the origin, propagation and life time of the cosmic ray. Since incident particles are in the region of relativistic velocity (the low energy cosmic ray below the cutoff energy is forbidden from entering), the charges of cosmic ray nuclei can be determined without knowing the energy of particles. The balloon-borne solid state track detector and plastic and X-ray films were employed for the detection of superheavy cosmic ray, and the five events were detected with the cellulose nitrate film. The flux of superheavy nuclei is predicted from the present analysis. (Yoshimori, M.)

  14. A Multi-Variate Fit to the Chemical Composition of the Cosmic-Ray Spectrum

    Science.gov (United States)

    Eisch, Jonathan

    Since the discovery of cosmic rays over a century ago, evidence of their origins has remained elusive. Deflected by galactic magnetic fields, the only direct evidence of their origin and propagation remain encoded in their energy distribution and chemical composition. Current models of galactic cosmic rays predict variations of the energy distribution of individual elements in an energy region around 3x1015 eV known as the knee. This work presents a method to measure the energy distribution of individual elemental groups in the knee region and its application to a year of data from the IceCube detector. The method uses cosmic rays detected by both IceTop, the surface-array component, and the deep-ice component of IceCube during the 2009-2010 operation of the IC-59 detector. IceTop is used to measure the energy and the relative likelihood of the mass composition using the signal from the cosmic-ray induced extensive air shower reaching the surface. IceCube, 1.5 km below the surface, measures the energy of the high-energy bundle of muons created in the very first interactions after the cosmic ray enters the atmosphere. These event distributions are fit by a constrained model derived from detailed simulations of cosmic rays representing five chemical elements. The results of this analysis are evaluated in terms of the theoretical uncertainties in cosmic-ray interactions and seasonal variations in the atmosphere. The improvements in high-energy cosmic ray hadronic-interaction models informed by this analysis, combined with increased data from subsequent operation of the IceCube detector, could provide crucial limits on the origin of cosmic rays and their propagation through the galaxy. In the course of developing this method, a number of analysis and statistical techniques were developed to deal with the difficulties inherent in this type of measurement. These include a composition-sensitive air shower reconstruction technique, a method to model simulated event

  15. Exploring the Cosmic Ray Spectrum with the CREAM Experiment

    CERN Document Server

    Anderson, Tyler B

    The Cosmic Ray Energetics and Mass (CREAM) project endeavors to resolve the cosmic-ray spectrum in an energy range between 10^{10} and 10^{15} eV for all particles with charges in the range Z = 1 (hydrogen) to Z = 26 (iron). From 2004 to 2011, the CREAM instrument was flown in a succession of long-duration balloon (LDB) missions over the Antarctic continent. To date, it has completed six successful campaigns, for a cumulative 161 days in flight. Starting in 2011, CREAM began a process of reconguration in order to prepare for ISSCREAM a three-year mission bound for the International Space Station in 2014. In addition, a subset of detectors from CREAM's balloon flights have been upgraded and reassembled for the Boron And Carbon Cosmic rays in the Upper Stratosphere (BACCUS) mission, which will mount a new LDB campaign during the 2013-2014 Antarctic summer season. The CREAM project is presented, with a special emphasis on the design, construction, and performance of CREAM's (and BACCUS') Timing Charge Detector (...

  16. EMMA: A new underground cosmic-ray experiment

    International Nuclear Information System (INIS)

    Enqvist, T; Foehr, V; Joutsenvaara, J; Jaemsen, T; Keraenen, P; Kuusiniemi, P; Laitala, H; Lehtola, M; Mattila, A; Narkilahti, J; Peltoniemi, J; Remes, H; Reponen, M; Raeihae, T; Sarkamo, J; Shen, C; Vaittinen, M; Zhang, Z; Ding, L; Zhu, Q; Roos, M; Dzaparova, I; Karpov, S; Kurenya, A; Petkov, V; Yanin, A; Fynbo, H

    2006-01-01

    A cosmic-ray experiment of new type is under construction in the Pyhaesalmi mine in the underground laboratory of the University of Oulu, Finland. It aims to study the composition of cosmic rays at and above the knee region (energy above 1 PeV). The experiment, called EMMA, covers about 150 m 2 of detector area, and the setup is capable of measuring the multiplicity and the lateral distribution of underground muons, and the arrival direction of the air shower. The detector is placed at the depth of about 85 metres (corresponding about 240 mwe) which gives a threshold energy of muons of about 45 GeV. The rock overburden filters out all other particles of the air shower except the high-energy muons. These high-energy muons originate at high altitudes close to the first interaction of the primary cosmic ray and they carry more information about the primary than low-energy muons. The full-size detector is supposed to run by the end of 2007

  17. Muon Production in Relativistic Cosmic-Ray Interactions

    International Nuclear Information System (INIS)

    Klein, Spencer R.

    2009-01-01

    Cosmic-rays with energies up to 3x10 20 eV have been observed. The nuclear composition of these cosmic rays is unknown but if the incident nuclei are protons then the corresponding center of mass energy is √(s nn )=700TeV. High energy muons can be used to probe the composition of these incident nuclei. The energy spectra of high-energy (>1TeV) cosmic ray induced muons have been measured with deep underground or under-ice detectors. These muons come from pion and kaon decays and from charm production in the atmosphere. Terrestrial experiments are most sensitive to far-forward muons so the production rates are sensitive to high-x partons in the incident nucleus and low-x partons in the nitrogen/oxygen targets. Muon measurements can complement the central-particle data collected at colliders. This paper will review muon production data and discuss some non-perturbative (soft) models that have been used to interpret the data. I will show measurements of TeV muon transverse momentum (p T ) spectra in cosmic-ray air showers from MACRO, and describe how the IceCube neutrino observatory and the proposed Km3Net detector will extend these measurements to a higher p T region where perturbative QCD should apply. With a 1 km 2 surface area, the full IceCube detector should observe hundreds of muons/year with p T in the pQCD regime.

  18. Solar flare neon and solar cosmic ray fluxes in the past using gas-rich meteorites

    International Nuclear Information System (INIS)

    Nautiyal, C.M.; Rao, M.N.

    1986-01-01

    Methods were developed earlier to deduce the composition of solar flare neon and to determine the solar cosmic ray proton fluxes in the past using etched lunar samples and at present, these techniques are extended to gas rich meteorites. By considering high temperature Ne data points for Pantar, Fayetteville and other gas rich meteorites and by applying the three component Ne-decomposition methods, the solar cosmic ray and galactic cosmic ray produced spallation Ne components from the trapped SF-Ne was resolved. Using appropiate SCR and GCR production rates, in the case of Pantar, for example, a GCR exposure age of 2 m.y. was estimated for Pantar-Dark while Pantar-Light yielded a GCR age of approx. 3 m.y. However the SCR exposure age of Pantar-Dark is two orders of magnitude higher than the average surface exposure ages of lunar soils. The possibility of higher proton fluxes in the past is discussed

  19. Cosmic ray-modified stellar winds. I. Solution topologies and singularities

    International Nuclear Information System (INIS)

    Ko, C.M.; Webb, G.M.

    1987-01-01

    In the present two-fluid hydrodynamical model for stellar wind flow modification due to its interaction with Galactic cosmic rays, these rays are coupled to the stellar wind by either hydromagnetic wave scattering or background flow irregularity propagation. The background flow is modified by the cosmic rays via their pressure gradient. The system of equations used possesses a line of singularities in (r, u, P/sub c/)-space, or a two-dimensional hypersurface of singularities in (r, u, P/sub c/, dP/sub c/dr)-space, where r, u, and P/sub c/ are respectively the radial distance from the star, the radial wind flow speed, and the cosmic ray pressure. The singular points may be nodes, foci, or saddle points. 64 references

  20. THE UNREASONABLE WEAKNESS OF R -PROCESS COSMIC RAYS IN THE NEUTRON-STAR-MERGER NUCLEOSYNTHESIS SCENARIO

    Energy Technology Data Exchange (ETDEWEB)

    Kyutoku, Koutarou [Interdisciplinary Theoretical Science (iTHES) Research Group, RIKEN, Wako, Saitama 351-0198 (Japan); Ioka, Kunihito, E-mail: koutarou.kyutoku@riken.jp [Center for Gravitational Physics, Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto, 606-8502 (Japan)

    2016-08-10

    We reach the robust conclusion that, by combining the observed cosmic rays of r -process elements with the fact that the velocity of the neutron-star-merger ejecta is much higher than that of the supernova ejecta, either (1) the reverse shock in the neutron-star-merger ejecta is a very inefficient accelerator that converts less than 0.003% of the ejecta kinetic energy to the cosmic-ray energy or (2) the neutron star merger is not the origin of the Galactic r -process elements. We also find that the acceleration efficiency should be less than 0.1% for the reverse shock of the supernova ejecta with observed cosmic rays lighter than the iron.