WorldWideScience

Sample records for low-energy cosmic-ray neutrons

  1. Instrumentation for continuous monitoring of low energy cosmic ray intensity

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S; Prasad, R; Yadav, R S [Aligarh Muslim Univ. (India). Dept. of Physics; Naqvi, T H [Z.H. Engineering Coll., Aligarh (India); Ahmed, Rais [National Council of Educational Research and Training, New Delhi (India)

    1975-12-01

    A high counting rate neutron monitor developed at Aligarh for continuous monitoring of low energy nucleonic component of cosmic rays is described. Transistorized electronic circuits used are described.

  2. Instrumentation for continuous monitoring of low energy cosmic ray intensity

    International Nuclear Information System (INIS)

    Kumar, S.; Prasad, R.; Yadav, R.S.; Ahmed, Rais

    1975-01-01

    A high counting rate neutron monitor developed at Aligarh for continuous monitoring of low energy nucleonic component of cosmic rays is described. Transistorized electronic circuits used are described. (author)

  3. 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

  4. Low-energy cosmic rays in the Orion region

    DEFF Research Database (Denmark)

    Pohl, M.

    1998-01-01

    The recently observed nuclear gamma-ray line emission from the Orion complex implies a high flux of low-energy cosmic rays (LECR) with unusual abundance. This cosmic ray component would dominate the energy density, pressure, and ionising power of cosmic rays, and thus would have a strong impact...

  5. A study of the cosmic-ray neutron field near interfaces

    CERN Document Server

    Sheu, R J; Jiang, S H

    2002-01-01

    This study investigated the characteristics of the cosmic-ray neutron field near air/ground and air/water interfaces with an emphasis on the angular distribution. Two sets of high-efficiency neutron detecting systems were used. The first one, called the Bonner Cylinders, was used for measurements of the energy information. The other one, referred to as the eight-channel neutron detector (8CND), was used to characterize the angular information of the neutron field. The measured results were used to normalize and confirm one-dimensional transport calculations for cosmic-ray neutrons below 20 MeV in the air/ground and air/water media. Annual sea level cosmic-ray neutron doses were then determined based on the obtained characteristics of low-energy cosmic-ray neutrons near interfaces and estimated contribution from high-energy neutrons.

  6. Altitude variation of cosmic-ray neutrons

    International Nuclear Information System (INIS)

    Nakamura, T.; Uwamino, Y.; Ohkubo, T.; Hara, A.

    1987-01-01

    The altitude variation of the cosmic-ray neutron energy spectrum and the dose equivalent rate was measured at an average geomagnetic latitude of 24 degrees N by using the high-efficiency multi-sphere neutron spectrometer and neutron dose-equivalent counter developed by the authors. The data were obtained from a 2-h flight over Japan on 27 February 1985. The neutron energy spectra measured at sea level and at altitudes of 4880 m and at 11,280 m were compared with the calculated spectra of O'Brien and with other experimental spectra, and they are in moderately good agreement with them. The dose equivalent rate increases according to a quadratic curve up to about 6000 m and then increases linearly between 6000 m and 11,280 m. The dependence of dose equivalent rates at sea level and at an altitude of 12,500 m on geomagnetic latitude also is given by referring to other experimental results

  7. Cosmic Ray Neutron Sensing in Complex Systems

    Science.gov (United States)

    Piussi, L. M.; Tomelleri, E.; Tonon, G.; Bertoldi, G.; Mejia Aguilar, A.; Monsorno, R.; Zebisch, M.

    2017-12-01

    Soil moisture is a key variable in environmental monitoring and modelling: being located at the soil-atmosphere boundary, it is a driving force for water, energy and carbon fluxes. Nevertheless its importance, soil moisture observations lack of long time-series at high acquisition frequency in spatial meso-scale resolutions: traditional measurements deliver either long time series with high measurement frequency at spatial point scale or large scale and low frequency acquisitions. The Cosmic Ray Neutron Sensing (CRNS) technique fills this gap because it supplies information from a footprint of 240m of diameter and 15 to 83 cm of depth at a temporal resolution varying between 15 minutes and 24 hours. In addition, being a passive sensing technique, it is non-invasive. For these reasons, CRNS is gaining more and more attention from the scientific community. Nevertheless, the application of this technique in complex systems is still an open issue: where different Hydrogen pools are present and where their distributions vary appreciably with space and time, the traditional calibration method shows some limits. In order to obtain a better understanding of the data and to compare them with remote sensing products and spatially distributed traditional measurements (i.e. Wireless Sensors Network), the complexity of the surrounding environment has to be taken into account. In the current work we assessed the effects of spatial-temporal variability of soil moisture within the footprint, in a steep, heterogeneous mountain grassland area. Measurement were performed with a Cosmic Ray Neutron Probe (CRNP) and a mobile Wireless Sensors Network. We performed an in-deep sensitivity analysis of the effects of varying distributions of soil moisture on the calibration of the CRNP and our preliminary results show how the footprint shape varies depending on these dynamics. The results are then compared with remote sensing data (Sentinel 1 and 2). The current work is an assessment of

  8. 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

  9. Measurement Over Large Solid Angle of Low Energy Cosmic Ray Muon Flux

    Science.gov (United States)

    Schreiner, H. F., III; Schwitters, R. F.

    2015-12-01

    Recent advancements in portable muon detectors have made cosmic ray imaging practical for many diverse applications. Working muon attenuation detectors have been built at the University of Texas and are already successfully being used to image tunnels, structures, and Mayan pyramids. Most previous studies have focused on energy measurements of the cosmic ray spectrum from of 1 GeV or higher. We have performed an accurate measurement of the ultra-low energy (muon spectrum down to the acceptance level of our detector, around one hundred MeV. Measurements include angular dependence, with acceptance approaching horizontal. Measurements were made underwater using a custom enclosure in Lake Travis, Austin, TX. This measurement will allow more accurate predictions and simulations of attenuation for small (muon tomography.

  10. Measuring the low-energy cosmic ray spectrum with the AFIS detector

    Energy Technology Data Exchange (ETDEWEB)

    Losekamm, Martin [Physics Department E18, Technische Universitaet Muenchen (Germany); Institute of Astronautics, Technische Universitaet Muenchen (Germany); Gaisbauer, Dominic; Greenwald, Daniel; Hahn, Alexander; Hauptmann, Philipp; Konorov, Igor; Meng, Lingxin; Paul, Stephan; Poeschl, Thomas [Physics Department E18, Technische Universitaet Muenchen (Germany); Renker, Dieter [Physics Department E17, Technische Universitaet Muenchen (Germany)

    2014-07-01

    High-energy cosmic rays interact with Earth's upper atmosphere and produce antiprotons, which can be trapped in Earth's magnetic field. The Antiproton Flux in Space (AFIS) Mission will measure the flux of trapped antiprotons with energies less than 100 MeV aboard the nanosatellite MOVE 2. An active-target tracking detector comprised of scintillating plastic fibers and silicon photomultipliers is already under construction at the Technische Universitaet Muenchen. As a precursor to the space-bound mission, a prototype version of the detector will be launched aboard a balloon from Kiruna, Sweden as part of the REXUS/BEXUS student program by the German Aerospace Center (DLR). Named AFIS-P, it will be used to measure the low-energy part of the cosmic-ray spectrum for energies less than 100 MeV-per-nucleon. Spectrometers in previous balloon missions were not sensitive in this low-energy region. Thus AFIS-P will deliver unprecedented data, while simultaneously allowing us to field-test the AFIS detector.

  11. Charge-equilibrium and radiation of low-energy cosmic rays passing through interstellar medium

    Science.gov (United States)

    Rule, D. W.; Omidvar, K.

    1977-01-01

    The charge equilibrium and radiation of an oxygen and an iron beam in the MeV per nucleon energy range, representing a typical beam of low-energy cosmic rays passing through the interstellar medium, is considered. Electron loss of the beam has been taken into account by means of the First Born approximation allowing for the target atom to remain unexcited, or to be excited to all possible states. Electron capture cross sections have been calculated by means of the scaled Oppenheimer-Brinkman-Kramers approximation, taking into account all atomic shells of the target atoms. Radiation of the beam due to electron capture into the excited states of the ion, collisional excitation and collisional inner-shell ionization of the ions has been considered. Effective X-ray production cross sections and multiplicities for the most energetic X-ray lines emitted by the Fe and O beams have been calculated.

  12. LEAP: A balloon-borne search for low-energy cosmic ray antiprotons

    Science.gov (United States)

    Moats, Anne Rosalie Myers

    The LEAP (Low Energy Antiproton) experiment is a search for cosmic ray antiprotons in the 120 MeV to 1.2 GeV kinetic energy range. The motivation for this project was the result announced by Buffington et al. (1981) that indicated an anomalously high antiproton flux below 300 MeV; this result has compelled theorists to propose sources of primary antiprotons above the small secondary antiproton flux produced by high energy cosmic ray collisions with nuclei in the interstellar medium. LEAP consisted of the NMSU magnet spectrometer, a time-of-flight system designed at NASA-Goddard, two scintillation detectors, and a Cherenkov counter. Analysis of flight data performed by the high energy astrophysics group at Goddard Space Flight Center revealed no antiproton candidates found in the 120 MeV to 360 MeV range; 3 possible antiproton candidate events were found in the 500 MeV to 1.2 GeV range in an analysis done here at the University of Arizona. However, since it will be necessary to sharpen the calibration on all of the LEAP systems in order to positively identify these events as antiprotons, only an upper limit has been determined at present. Thus, combining the analyses performed at the University of Arizona and NASA-Goddard, 90 percent confidence upper limits of 3.5 x 10-5 in the 120 MeV to 360 MeV range and 2.3 x 10-4 in the 500 MeV to 1.2 GeV range for the antiproton/proton ratio is indicated by the LEAP results. LEAP disagrees sharply with the results of the Buffington group, indicating a low antiproton flux at these energies. Thus, a purely secondary antiproton flux may be adequate at low energies.

  13. LEAP [Low-Energy Antiproton]: A balloon-borne search for low-energy cosmic-ray antiprotons

    International Nuclear Information System (INIS)

    Moats, A.R.M.

    1989-01-01

    The LEAP (Low-Energy Antiproton) experiment is a search for cosmic-ray antiprotons in the 120 MeV to 1.2 GeV kinetic energy range. The motivation for this project was the result announced by Buffington et. al. (1981) that indicated an anomalously high antiproton flux below 300 MeV; this result has compelled theorists to propose sources of primary antiprotons above the small secondary antiproton flux produced by high energy cosmic-ray collisions with nuclei in the interstellar medium. LEAP consisted of the NMSU magnetic spectrometer, a time-of-flight system designed at Goddard Space Flight Center, two scintillation detectors, and a Cherenkov counter designed and built at the University of Arizona. Analysis of flight data performed by the high-energy astrophysics group at Goddard Space Flight Center revealed no antiproton candidates found in the 120 MeV to 360 MeV range; 3 possible antiproton candidate events were found in the 500 MeV to 1.2 GeV range in an analysis done here at the University of Arizona. However, since it will be necessary to sharpen the calibration on all of the LEAP systems in order to positively identify these events as antiprotons, only an upper limit has been determined at present. Thus, combining the analyses performed at the University of Arizona and Goddard Space Flight Center, 90% confidence upper limits of 3.5 x 10 -5 in the 120 MeV to 360 MeV range and 2.3 x 10 -4 in the 500 MeV to 1.2 GeV range for the antiproton/proton ratio is indicated by the LEAP results. LEAP disagrees sharply with the results of the Buffington group, indicating a low antiproton flux at these energies

  14. R -process Element Cosmic Rays from Neutron Star Mergers

    Energy Technology Data Exchange (ETDEWEB)

    Komiya, Yutaka; Shigeyama, Toshikazu [Research Center for the Early Universe, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, 113-0033, Tokyo (Japan)

    2017-09-10

    Neutron star mergers (NSMs) are one of the most plausible sources of r -process elements in the universe. Therefore, NSMs can also be a major source of ultra-heavy elements in cosmic rays. In this paper, we first estimate the contribution of r -process elements synthesized in NSMs to the ultra-heavy element cosmic rays (UHCRs) by calculating transport equations that take into account energy loss processes and spallations. We show that the flux of UHCRs accelerated by the NSMs themselves fluctuates by many orders of magnitude on a timescale of several million years and can overwhelm UHCRs accelerated by supernova remnants (SNRs) after an NSM takes place within a few kiloparsec from the solar system. Experiments with very long exposure times using meteorites as UHCR detectors can detect this fluctuation. As a consequence, we show that if NSMs are the primary source of UHCRs, future experiments using meteorites may be able to reveal the event history of NSMs in the solar vicinity. We also describe a possible difference in the abundance pattern and energy spectrum of UHCRs between NSM and SNR accelerations.

  15. Charge equilibrium and radiation of low-energy cosmic rays passing through interstellar medium

    International Nuclear Information System (INIS)

    Rule, D.W.; Omidvar, K.

    1979-01-01

    The charge equilibrium and radiation an oxygen and an iron beam in the MeV per nucleon energy range, representing a typical beam of low-energy cosmic rays passing through the interstellar medium, are considered. Electron loss of the beam has been taken into account by means of the first Born approximation allowing for the target atom to remain unexcited, or to be excited to all possible states. Electron-capture cross sections have been calculated by means of the scaled Oppenheimer-Brinkman-Kramers approximation, taking into account of atomic shells of the target atoms and capture into all excited states of the projectile. The capture and loss cross sections are found to be within 20%--30% of the existing experimental values for most of the cases considered. Radiation of the beam due to electron capture into the excited states of the ion, collisional excitation, and collisional inner-shell ionization, taking into account the fluorescence yield of the ions has been considered. Effective X-ray production cross sections and mutliplicities for the most energetic X-ray lines emitted by the Fe and O beams have been calculated, and error estimates made for the results

  16. Charge equilibrium and radiation of low-energy cosmic rays passing through interstellar medium

    Science.gov (United States)

    Rule, D. W.; Omidvar, K.

    1979-01-01

    The charge equilibrium and radiation of an oxygen and an iron beam in the MeV per nucleon energy range, representing a typical beam of low-energy cosmic rays passing through the interstellar medium, are considered. Electron loss of the beam has been taken into account by means of the first Born approximation, allowing for the target atom to remain unexcited or to be excited to all possible states. Electron-capture cross sections have been calculated by means of the scaled Oppenheimer-Brinkman-Kramers approximation, taking into account all atomic shells of the target atoms and capture into all excited states of the projectile. The capture and loss cross sections are found to be within 20%-30% of the existing experimental values for most of the cases considered. Radiation of the beam due to electron capture into the excited states of the ion, collisional excitation, and collisional inner-shell ionization, taking into account the fluorescence yield of the ions, has been considered. Effective X-ray production cross sections and multiplicities for the most energetic X-ray lines emitted by the Fe and O beams have been calculated, and error estimates made for the results.

  17. Neutron production by cosmic-ray muons in various materials

    Science.gov (United States)

    Manukovsky, K. V.; Ryazhskaya, O. G.; Sobolevsky, N. M.; Yudin, A. V.

    2016-07-01

    The results obtained by studying the background of neutrons produced by cosmic-raymuons in underground experimental facilities intended for rare-event searches and in surrounding rock are presented. The types of this rock may include granite, sedimentary rock, gypsum, and rock salt. Neutron production and transfer were simulated using the Geant4 and SHIELD transport codes. These codes were tuned via a comparison of the results of calculations with experimental data—in particular, with data of the Artemovsk research station of the Institute for Nuclear Research (INR, Moscow, Russia)—as well as via an intercomparison of results of calculations with the Geant4 and SHIELD codes. It turns out that the atomic-number dependence of the production and yield of neutrons has an irregular character and does not allow a description in terms of a universal function of the atomic number. The parameters of this dependence are different for two groups of nuclei—nuclei consisting of alpha particles and all of the remaining nuclei. Moreover, there are manifest exceptions from a power-law dependence—for example, argon. This may entail important consequences both for the existing underground experimental facilities and for those under construction. Investigation of cosmic-ray-induced neutron production in various materials is of paramount importance for the interpretation of experiments conducted at large depths under the Earth's surface.

  18. 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

  19. Cosmic Rays and Clouds, 1. Formation of Lead Mesoatoms In Neutron Monitor By Soft Negative Muons and Expected Atmospheric Electric Field Effect In The Cosmic Ray Neutron Component

    Science.gov (United States)

    Dorman, L. I.; Dorman, I. V.

    We extend our model (Dorman and Dorman, 1995) of cosmic ray atmospheric electric field effect on the case of neutron monitor. We take into account that about 0.07 of neu- tron monitor counting rate caused by negative soft muons captured by lead nucleons and formed mesoatoms with generation of several MeV energy neutrons from lead. In this case the neutron monitor or neutron supermonitor works as analyzer which de- tects muons of only one, negative sign. It is very important because the atmospheric electric field effect have opposite signs for positive and negative muons that main part of this effect in the muon telescope or in ionization chamber is compensated and we can observe only small part of total effect of one sign muons. On the basis of our gen- eral theory of cosmic ray meteorological effects with taking into account of negative soft muon acceleration and deceleration in the Earth atmosphere (in dependence of di- rection and intensity of electric field) we discuss the possibility of existing this effect in cosmic ray neutron component and made some rough estimations. REFERENCES: Dorman L.I. and Dorman I.V., 1995. "Cosmic-ray atmospheric electric field effects". Canadian J. of Physics, Vol. 73, pp. 440-443.

  20. Evaluation of the Neutron Detector Response for Cosmic Ray Energy Spectrum by Monte Carlo Transport Simulation

    International Nuclear Information System (INIS)

    Pazianotto, Mauricio T.; Carlson, Brett V.; Federico, Claudio A.; Gonzalez, Odair L.

    2011-01-01

    Neutrons generated by the interaction of cosmic rays with the atmosphere make an important contribution to the dose accumulated in electronic circuits and aircraft crew members at flight altitude. High-energy neutrons are produced in spallation reactions and intranuclear cascade processes by primary cosmic-ray particle interactions with atoms in the atmosphere. These neutrons can produce secondary neutrons and also undergo a moderation process due to atmosphere interactions, resulting in a wider energy spectrum, ranging from thermal energies (0.025 eV) to energies of several hundreds of MeV. The Long-Counter (LC) detector is a widely used neutron detector designed to measure the directional flux of neutrons with about constant response over a wide energy range (thermal to 20 MeV). ). Its calibration process and the determination of its energy response for the wide-energy of cosmic ray induced neutron spectrum is a very difficult process due to the lack of installations with these capabilities. The goal of this study is to assess the behavior of the response of a Long Counter using the Monte Carlo (MC) computational code MCNPX (Monte Carlo N-Particle eXtended). The dependence of the Long Counter response on the angle of incidence, as well as on the neutron energy, will be carefully investigated, compared with the experimental data previously obtained with 241 Am-Be and 252 Cf neutron sources and extended to the neutron spectrum produced by cosmic rays. (Author)

  1. Cosmic Ray induced Neutron and Gamma-Ray bursts in a Lead Pile

    International Nuclear Information System (INIS)

    Chapline, G; Hagmann, C; Kerr, P; Snyderman, N J; Wurtz, R

    2007-01-01

    The neutron background is created primarily by cosmic rays interactions. Of particular interest for SNM detection is an understanding of burst events that resemble fission chains. We have been studying the interaction of cosmic rays with a lead pile that is efficient at creating neutron bursts from cosmic ray interactions. The neutron burst size depends on the configuration of the lead. We have found that the largest bursts appear to have been created by primaries of energy over 100 GeV that have had a diffractive interaction with the atmosphere. The large events trigger muon coincidence paddles with very high efficiency, and the resulting interactions with the lead pile can create over 10, 000 neutrons in a burst

  2. Transport coefficients of low-energy cosmic rays in interplanetary space

    International Nuclear Information System (INIS)

    Palmer, I.

    1982-01-01

    The propagation of energetic particles along and across the interplantary magnetic field is governed by the large-scale field geometry and by scattering in small-scale turbulent fields. Values of the scattering mean free path parallel to the field, γ/sub parallel/ (R), are reviewed in prompt solar bursts and nonimpulsive (corotating) events. Analysis of intensity and anisotropy profiles in combination is a powerful tool for elucidating γ/sub parallel/ (R). A consensus is found: at 1 AU, γ/sub parallel/ = 0.08--0.3 AU over a wide range of rigidity, R = 5 x 10 -4 to 5 GV. Efforts to explain the discrepancy between empirical values of γ/sub parallel/ and scattering theory are discussed. Quantitative measures of γ/sub parallel/ in rare scatter-free events, where magnetic power spectra. Cross-field diffusion due to random walk of field lines is revisited. Recent values deduced from magnetic power spectra in interplanetary space, magnetic diffusion at the sun, Jovian electron propagation, and cosmic ray events are evaluated. Again, a consensus is sought, and a reasonable mean is K/sub perpendicular//sup r//β = 10 21 cm 2 s -1 . Previous arguments against a significant K/sub perpendicular//sup r/ are reassessed, including the problem of the persistance of intensity fluctuations in cosmic ray events. Combining the consensus for K/sub perpendicular//sup r//β with that for γ/sub parallel/<0.1 at 1 AU, and thus neglect of K/sub perpendicular//sup r/ in the modeling of solar cosmic ray events appears justified (although account needs to be taken of coronal propagation). The outlook for the future includes better empirical values of γ/sub parallel/ down to E/sub p/approx.10 keV and E/sub e/approx. 1 keV, comparison with scattering theories at these energies, and comparison between empirical and theoretical γ/sub parallel/ in other regions such as the magnetosheath and upstream solar wind

  3. Ames collaborative study of cosmic-ray neutrons. II. Low- and mid-latitude flights

    International Nuclear Information System (INIS)

    Stephens, L.D.; McCaslin, J.B.; Smith, A.R.; Thomas, R.H.; Hewitt, J.E.; Hughes, L.

    1978-01-01

    The continuing progress of the Ames Collaborative Study of Cosmic Ray Neutrons is described. Data obtained aboard flights from Hawaii at altitudes of 41,000 and 45,000 feet, and in the range of geomagnetic latitude 17 0 N less than or equal to lambda less than or equal to 21 0 N are reported. Preliminary estimates of neutron spectra were made

  4. 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.

  5. Footprint Characteristics of Cosmic-Ray Neutron Sensors for Soil Moisture Monitoring

    Science.gov (United States)

    Schrön, Martin; Köhli, Markus; Zreda, Marek; Dietrich, Peter; Zacharias, Steffen

    2015-04-01

    Cosmic-ray neutron sensing is a unique and an increasingly accepted method to monitor the effective soil water content at the field scale. The technology is famous for its low maintenance, non-invasiveness, continuous measurement, and most importantly, for its large footprint. Being more representative than point data and finer resolved than remote-sensing products, cosmic-ray neutron derived soil moisture products provide unrivaled advantage for mesoscale hydrologic and land surface models. The method takes advantage of neutrons induced by cosmic radiation which are extraordinarily sensitive to hydrogen and behave like a hot gas. Information about nearby water sources are quickly mixed in a domain of tens of hectares in air. Since experimental determination of the actual spatial extent is hardly possible, scientists have applied numerical models to address the footprint characteristics. We have revisited previous neutron transport simulations and present a modified conceptual design and refined physical assumptions. Our revised study reveals new insights into probing distance and water sensitivity of detected neutrons under various environmental conditions. These results sharpen the range of interpretation concerning the spatial extent of integral soil moisture products derived from cosmic-ray neutron counts. Our findings will have important impact on calibration strategies, on scales for data assimilation and on the interpolation of soil moisture data derived from mobile cosmic-ray neutron surveys.

  6. Exploring the potential of the cosmic-ray neutron method to measure interception storage dynamics

    Science.gov (United States)

    Jakobi, Jannis; Bogena, Heye; Huisman, Johan Alexander; Diekkrüger, Bernd; Vereecken, Harry

    2017-04-01

    Cosmic-ray neutron soil moisture probes are an emerging technology that relies on the negative correlation between near-surface fast neutron counts and soil moisture content. Hydrogen atoms in the soil, which are mainly present as water, moderate the secondary neutrons on the way back to the surface. Any application of this method needs to consider the sensitivity of the neutron counts to additional sources of hydrogen (e.g. above- and below-ground biomass, humidity of the lower atmosphere, lattice water of the soil minerals, organic matter and water in the litter layer, intercepted water in the canopy, and soil organic matter). In this study, we analyzed the effects of canopy-intercepted water on the cosmic-ray neutron counts. For this, an arable field cropped with sugar beet was instrumented with several cosmic-ray neutron probes and a wireless sensor network with more than 140 in-situ soil moisture sensors. Additionally rainfall interception was estimated using a new approach coupling throughfall measurements and leaf wetness sensors. The derived interception storage was used to correct for interception effects on cosmic ray neutrons to enhance soil water content prediction. Furthermore, the potential for a simultaneous prediction of above- and below-ground biomass, soil moisture and interception was tested.

  7. Peculiarities of the Moon variations of the neutron and meson components of cosmic rays

    International Nuclear Information System (INIS)

    Naskidashvili, B.D.; Shatashvili, L.Kh.

    1979-01-01

    Lunar variations of the neutron component of cosmic rays have been investigated individually for groups of stations of the northern hemisphere of the Earth and for groups of stations of the southern hemisphere. A dependence has been found of the amplitude and phase of the first harmonic of lunar variations in the intensity of neutron and meson components of cosmic rays on the geocentric distance of the Moon and on the epoch of solar activity. The amplitudes and phases of lunar variations were determined by the Chapman-Miller method. According to the data on the meson component of cosmic rays obtained by the Nagoya station (Japan), the amplitudes of the first harmonic of lunar daily variations point to the fact that as the Moon approaches the Earth the tidal effects do not exceed the effects of lunar gravitational forces when the Moon is at apogee

  8. STUDIES OF COSMIC-RAY MUONS AND NEUTRONS IN A FIVE-STORY CONCRETE BUILDING.

    Science.gov (United States)

    Chen, Wei-Lin; Sheu, Rong-Jiun

    2018-05-01

    This study thoroughly determined the flux and dose rate distributions of cosmic-ray muons and neutrons in a five-story concrete building by comparing measurements with Monte Carlo simulations of cosmic-ray showers. An angular-energy-dependent surface source comprising secondary muons and neutrons at a height of 200 m above ground level was established and verified, which was used to concatenate the shower development in the upper atmosphere with subsequent simulations of radiation transport down to ground level, including the effect of the terrain and studied building. A Berkeley Lab cosmic-ray detector and a highly sensitive Bonner cylinder were used to perform muon and neutron measurements on each building floor. After careful calibration and correction, the measured responses of the two detectors were discovered to be reasonably consistent with the theoretical predictions, thus confirming the validity of the two-step calculation model employed in this study. The annual effective doses from cosmic-ray muons and neutrons on the open roof of the building were estimated to be 115.2 and 35.2 μSv, respectively. Muons and neutrons were attenuated floor-by-floor with different attenuation factors of 0.97 and 0.78, and their resultant dose rates on the first floor of the building were 97.8 and 9.9 μSv, respectively.

  9. Multitaper spectral analysis of cosmic rays Sao Martinho da Serra's muon telescope and Newark's neutron monitor data

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Marlos Rockenbach da; Alarcon, Walter Demetrio Gonzalez; Echer, Ezequiel; Lago, Alisson dal; Lucas, Aline de [National Institute for Space Research - INPE-MCT, Sao Jose dos Campos, SP (Brazil); Vieira, Luis Eduardo Antunes; Guarnieri, Fernando Luis [Universidade do Vale do Paraiba - UNIVAP, Sao Jose dos Campos, SP (Brazil); Schuch, Nelson Jorge [Southern Regional Space Research Center - CRSPE/INPE-MCT, Santa Maria, RS (Brazil); Munakata, Kazuoki, E-mail: marlos@dge.inpe.br, E-mail: gonzalez@dge.inpe.br, E-mail: eecher@dge.inpe.br, E-mail: dallago@dge.inpe.br, E-mail: delucas@dge.inpe.br, E-mail: levieira@univap.br, E-mail: guarnieri@univap.br, E-mail: njschuch@lacesm.ufsm.br, E-mail: kmuna00@gipac.shinshu-u.ac.jp [Physics Department, Shinshu University, Matsumoto (Japan)

    2007-07-01

    In this work we present an analysis on the correction efficiency of atmospheric effects on cosmic ray Sao Martinho da Serra's muon telescope and Newark's neutron monitor data. We use a Multitaper spectral analysis of cosmic rays time series to show the main periodicities present in the corrected and uncorrected data for the atmospheric effects. This kind of correction is very important when intends to study cosmic rays variations of extra-terrestrial origin. (author)

  10. The ionizing effect of low-energy cosmic rays from a class II object on its protoplanetary disc

    Science.gov (United States)

    Rodgers-Lee, D.; Taylor, A. M.; Ray, T. P.; Downes, T. P.

    2017-11-01

    We investigate the ionizing effect of low-energy cosmic rays (CRs) from a young star on its protoplanetary disc (PPD). We consider specifically the effect of ∼3 GeV protons injected at the inner edge of the PPD. An increase in the ionization fraction as a result of these CRs could allow the magnetorotational instability to operate in otherwise magnetically dead regions of the disc. For the typical values assumed we find an ionization rate of ζCR ∼ 10-17 s-1 at 1 au. The transport equation is solved by treating the propagation of the CRs as diffusive. We find for increasing diffusion coefficients the CRs penetrate further in the PPD, while varying the mass density profile of the disc is found to have little effect. We investigate the effect of an energy spectrum of CRs. The influence of a disc wind is examined by including an advective term. For advective wind speeds between 1 and 100 km s-1 diffusion dominates at all radii considered here (out to 10 au) for reasonable diffusion coefficients. Overall, we find that low-energy CRs can significantly ionize the mid-plane of PPDs out to ∼1 au. By increasing the luminosity or energy of the CRs, within plausible limits, their radial influence could increase to ∼2 au at the mid-plane but it remains challenging to significantly ionize the mid-plane further out.

  11. Cosmic-ray neutron transport at a forest field site

    DEFF Research Database (Denmark)

    Andreasen, Mie; Jensen, Karsten Høgh; Desilets, Darin

    2017-01-01

    -ray neutron intensity is essential (e.g., the effect of vegetation, litter layer and soil type). In this study the environmental effect is examined by performing a sensitivity analysis using neutron transport modeling. We use a neutron transport model with various representations of the forest and different...

  12. Aerial Neutron Detection of Cosmic-Ray Interactions with the Earth's Surface

    International Nuclear Information System (INIS)

    Richard Maurer

    2008-01-01

    We have demonstrated the ability to measure the neutron flux produced by the cosmic-ray interaction with nuclei in the ground surface using aerial neutron detection. High energy cosmic-rays (primarily muons with GeV energies) interact with the nuclei in the ground surface and produce energetic neutrons via spallation. At the air-surface interface, the neutrons produced by spallation will either scatter within the surface material, become thermalized and reabsorbed, or be emitted into the air. The mean free path of energetic neutrons in air can be hundreds of feet as opposed to a few feet in dense materials. As such, the flux of neutrons escaping into the air provides a measure of the surface nuclei composition. It has been demonstrated that this effect can be measured at long range using neutron detectors on low flying helicopters. Radiological survey measurements conducted at Government Wash in Las Vegas, Nevada, have shown that the neutron background from the cosmic-soil interactions is repeatable and directly correlated to the geological data. Government Wash has a very unique geology, spanning a wide variety of nuclide mixtures and formations. The results of the preliminary measurements are presented

  13. Cosmic-ray-induced ship-effect neutron measurements and implications for cargo scanning at borders

    Energy Technology Data Exchange (ETDEWEB)

    Kouzes, Richard T. [Pacific Northwest National Laboratory, MS K7-36, P.O. Box 999, Richland, WA 99352 (United States)], E-mail: richard.kouzes@pnl.gov; Ely, James H.; Seifert, Allen; Siciliano, Edward R.; Weier, Dennis R.; Windsor, Lindsay K.; Woodring, Mitchell L. [Pacific Northwest National Laboratory, MS K7-36, P.O. Box 999, Richland, WA 99352 (United States); Borgardt, James; Buckley, Elise; Flumerfelt, Eric; Oliveri, Anna; Salvitti, Matt [Juniata College Physics Department, 1700 Moore St., Huntingdon, PA 16652 (United States)

    2008-03-11

    Neutron measurements are used as part of the interdiction process for illicit nuclear materials at border crossings. Even though the natural neutron background is small, its variation can impact the sensitivity of detection systems. The natural background of neutrons that is observed in monitoring instruments arises almost entirely from cosmic-ray-induced cascades in the atmosphere and the surrounding environment. One significant source of variation in the observed neutron background is produced by the 'ship effect' in large quantities of cargo that transit past detection instruments. This paper reports on results from measurements with typical monitoring equipment of ship effect neutrons in various materials. One new result is the 'neutron shadow shielding' effect seen with some low neutron density materials.

  14. Neutron monitor latitude survey of cosmic ray intensity during the 1986/1987 solar minimum

    International Nuclear Information System (INIS)

    Moraal, H.; Potgieter, M.S.; Stoker, P.H.; van der Walt, A.J.

    1989-01-01

    A latitude survey of the cosmic ray intensity at sea level was conducted during the 1986/1987 solar minimum period on commercial vessels of the South African Marine Corporation (SAFMARINE). The results show that the differential response function for the 1986/1987 solar minimum agrees well with that measured in 1965. Both these response functions are significantly lower than those for 1976 and 1954. This result supports the 22-year modulation cycle as predicted, for example, by models including drift effects of the charged cosmic ray particles in the large-scale interplanetary magnetic field. A crossover of the spectra at rigidities of about 7 GV was also observed. Such a crossover is necessary to explain both the stationary neutron monitor counting rates and the lower-energy balloon and space observations in consecutive solar cycles. copyright American Geophysical Union 1989

  15. Analysis of cosmic ray neutron-induced single-event phenomena

    International Nuclear Information System (INIS)

    Tukamoto, Yasuyuki; Watanabe, Yukinobu; Nakashima, Hideki

    2003-01-01

    We have developed a database of cross sections for the n+ 28 Si reaction in the energy range between 2 MeV and 3 GeV in order to analyze single-event upset (SEU) phenomena induced by cosmic-ray neutrons in semiconductor memory devices. The data are applied to calculations of SEU cross sections using the Burst Generation Rate (BGR) model including two parameters, critical charge and effective depth. The calculated results are compared with measured SEU cross-sections for energies up to 160 MeV, and the reaction products that provide important effects on SEU are mainly investigated. (author)

  16. Modulation of cosmic rays with particular reference to the Hermanus neutron monitor

    International Nuclear Information System (INIS)

    Stoker, P.H.

    1982-01-01

    Investigations at Potchefstroom has directed interest to the interaction between cosmic rays and the interplanetary magnetic field. In this paper the period of increasing modulation of cosmic rays from 1976 is discussed. The geomagnetic field as spectrometer for primary cosmic rays will be discussed and applied to the latitude surveys of 1975 and 1976. Features of the coronal magnetic field, the solar wind with interplanetary magnetic field and the transport of cosmic rays in the interplanetary magnetic field are outlined in order to relate cosmic ray recordings of fixed groundlevel stations to observations made in outerspace by space crafts and satellites and to explain these recordings in terms of cosmic ray modulation processes

  17. Forward to all-around survey of environmental neutrons from cosmic ray secondary neutron measurements. History and prospects

    International Nuclear Information System (INIS)

    Aratani, M.

    2000-01-01

    At the present stage of our civilization, environmental neutrons come from not only cosmic ray but also the various kinds of nuclear facilities where uranium, plutonium, californium-252, and other transuranium elements are treated in a large scale. To be regret, those neutron-emitting elements have already been released into the environment by experiments with the military purpose, and been distributed among atmosphere, hydrosphere and geosphere in further larger scale than the peaceful use of nuclear energy. Now environmental neutrons should be surveyed against the horizontal component from the nuclear facilities, upward component from soil, and downward component as secondary neutron from cosmic ray, which is to be regarded as background neutron in the environment. The third category of neutrons have long been surveyed by Y. Nishina and his group of the Institute of Physical and Chemical Research (IPCR) since 1970 at the Itabashi Branch (Itabashi, Tokyo) of IPCR. The BF 3 gas-filled monitors (20 cm in diameter x 200 cm) of 28 (36 at maximum) vessels were used for neutrons till Sept. of 1998, and were transferred to Yanpahchin, Tibet, China for the primary neutrons that might be preferred to secondary ones by researchers of the cosmic ray. A critical accident happened at the Tokai facilities of JCO (Japan Conversion Organization) on Sept. 30 1999, and was discussed in various contexts at home and in a severe tone abroad. A background survey of the environmental neutrons has not been made at any nuclear site or facilities concerning fission in this country. The neutron monitor which detected and recorded the neutrons from the JCO critical accidents was what had been equipped for the fusion research, but not for fission application. Radiation education on neutron has not been made in both school and social education. Basic scientists also may be responsible for the critical accident through making light of these fundamental aspects of nuclear technology. In this

  18. Calibration and correction procedures for cosmic-ray neutron soil moisture probes located across Australia

    Science.gov (United States)

    Hawdon, Aaron; McJannet, David; Wallace, Jim

    2014-06-01

    The cosmic-ray probe (CRP) provides continuous estimates of soil moisture over an area of ˜30 ha by counting fast neutrons produced from cosmic rays which are predominantly moderated by water molecules in the soil. This paper describes the setup, measurement correction procedures, and field calibration of CRPs at nine locations across Australia with contrasting soil type, climate, and land cover. These probes form the inaugural Australian CRP network, which is known as CosmOz. CRP measurements require neutron count rates to be corrected for effects of atmospheric pressure, water vapor pressure changes, and variations in incoming neutron intensity. We assess the magnitude and importance of these corrections and present standardized approaches for network-wide analysis. In particular, we present a new approach to correct for incoming neutron intensity variations and test its performance against existing procedures used in other studies. Our field calibration results indicate that a generalized calibration function for relating neutron counts to soil moisture is suitable for all soil types, with the possible exception of very sandy soils with low water content. Using multiple calibration data sets, we demonstrate that the generalized calibration function only applies after accounting for persistent sources of hydrogen in the soil profile. Finally, we demonstrate that by following standardized correction procedures and scaling neutron counting rates of all CRPs to a single reference location, differences in calibrations between sites are related to site biomass. This observation provides a means for estimating biomass at a given location or for deriving coefficients for the calibration function in the absence of field calibration data.

  19. Background estimation of cosmic-ray induced neutrons in Chooz site water veto tank for possible future Ricochet Deployment

    Science.gov (United States)

    Silva, James

    2017-09-01

    The Ricochet experiment seeks to measure Coherent (neutral-current) Elastic Neutrino-Nucleus Scattering (CE νNS) using metallic superconducting and germanium semi-conducting detectors with sub-keV thresholds placed near a neutrino source such as the Chooz Nuclear Reactor Complex. In this poster, we present an estimate of the flux of cosmic-ray induced neutrons, which represent an important background in any (CE νNS) search, based on reconstructed cosmic ray data from the Chooz Site. We have simulated a possible Ricochet deployment at the Chooz site in GEANT4 focusing on the spallation neutrons generated when cosmic rays interact with the water tank veto that would surround our detector. We further simulate and discuss the effectiveness of various shielding configurations for optimizing the background levels for a future Ricochet deployment.

  20. 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)

  1. Cosmic Ray Neutron Sensing: Use, Calibration and Validation for Soil Moisture Estimation

    International Nuclear Information System (INIS)

    2017-03-01

    Nuclear and related techniques can help develop climate-smart agricultural practices by optimizing water use efficiency. The measurement of soil water content is essential to improve the use of this resource in agriculture. However, most sensors monitor small areas (less than 1m in radius), hence a large number of sensors are needed to obtain soil water content across a large area. This can be both costly and labour intensive and so larger scale measuring devices are needed as an alternative to traditional point-based soil moisture sensing techniques. The cosmic ray neutron sensor (CRNS) is such a device that monitors soil water content in a non-invasive and continuous way. This publication provides background information about this novel technique, and explains in detail the calibration and validation process.

  2. Assessment of soil moisture dynamics on an irrigated maize field using cosmic ray neutron sensing

    Science.gov (United States)

    Scheiffele, Lena Maria; Baroni, Gabriele; Oswald, Sascha E.

    2015-04-01

    In recent years cosmic ray neutron sensing (CRS) developed as a valuable, indirect and non-invasive method to estimate soil moisture at a scale of tens of hectares, covering the gap between point scale measurements and large scale remote sensing techniques. The method is particularly promising in cropped and irrigated fields where invasive installation of belowground measurement devices could conflict with the agricultural management. However, CRS is affected by all hydrogen pools in the measurement footprint and a fast growing biomass provides some challenges for the interpretation of the signal and application of the method for detecting soil moisture. For this aim, in this study a cosmic ray probe was installed on a field near Braunschweig (Germany) during one maize growing season (2014). The field was irrigated in stripes of 50 m width using sprinkler devices for a total of seven events. Three soil sampling campaigns were conducted throughout the growing season to assess the effect of different hydrogen pools on calibration results. Additionally, leaf area index and biomass measurements were collected to provide the relative contribution of the biomass on the CRS signal. Calibration results obtained with the different soil sampling campaigns showed some discrepancy well correlated with the biomass growth. However, after the calibration function was adjusted to account also for lattice water and soil organic carbon, thus representing an equivalent water content of the soil, the differences decreased. Soil moisture estimated with CRS responded well to precipitation and irrigation events, confirming also the effective footprint of the method (i.e., radius 300 m) and showing occurring water stress for the crop. Thus, the dynamics are in agreement with the soil moisture determined with point scale measurements but they are less affected by the heterogeneous moisture conditions within the field. For this reason, by applying a detailed calibration, CRS proves to be a

  3. The potential of detecting intermediate-scale biomass and canopy interception in a coniferous forest using cosmic-ray neutron intensity measurements and neutron transport modeling

    Science.gov (United States)

    Andreasen, M.; Looms, M. C.; Bogena, H. R.; Desilets, D.; Zreda, M. G.; Sonnenborg, T. O.; Jensen, K. H.

    2014-12-01

    The water stored in the various compartments of the terrestrial ecosystem (in snow, canopy interception, soil and litter) controls the exchange of the water and energy between the land surface and the atmosphere. Therefore, measurements of the water stored within these pools are critical for the prediction of e.g. evapotranspiration and groundwater recharge. The detection of cosmic-ray neutron intensity is a novel non-invasive method for the quantification of continuous intermediate-scale soil moisture. The footprint of the cosmic-ray neutron probe is a hemisphere of a few hectometers and subsurface depths of 10-70 cm depending on wetness. The cosmic-ray neutron method offers measurements at a scale between the point-scale measurements and large-scale satellite retrievals. The cosmic-ray neutron intensity is inversely correlated to the hydrogen stored within the footprint. Overall soil moisture represents the largest pool of hydrogen and changes in the soil moisture clearly affect the cosmic-ray neutron signal. However, the neutron intensity is also sensitive to variations of hydrogen in snow, canopy interception and biomass offering the potential to determine water content in such pools from the signal. In this study we tested the potential of determining canopy interception and biomass using cosmic-ray neutron intensity measurements within the framework of the Danish Hydrologic Observatory (HOBE) and the Terrestrial Environmental Observatories (TERENO). Continuous measurements at the ground and the canopy level, along with profile measurements were conducted at towers at forest field sites. Field experiments, including shielding the cosmic-ray neutron probes with cadmium foil (to remove lower-energy neutrons) and measuring reference intensity rates at complete water saturated conditions (on the sea close to the HOBE site), were further conducted to obtain an increased understanding of the physics controlling the cosmic-ray neutron transport and the equipment used

  4. 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.)

  5. Nuclear data relevant to single event upsets in semiconductor memories induced by cosmic-ray neutrons and protons

    International Nuclear Information System (INIS)

    Watanabe, Yukinobu

    2008-01-01

    The role of nuclear data is examined in the study of single event upset (SEU) phenomena in semiconductor memories caused by cosmic-ray neutrons and protons. Neutron and proton SEU cross sections are calculated with a simplified semi-empirical model using experimental heavy-ion SEU cross-sections and a dedicated database of neutron and proton induced reactions on 28 Si. Some impacts of the nuclear reaction data on SEU simulation are analyzed by investigating relative contribution of secondary ions and neutron elastic scattering to SEU and influence of simultaneous multiple ions emission on SEU. (author)

  6. Fundamental physics with low-energy neutrons

    International Nuclear Information System (INIS)

    Barrón-Palos, Libertad

    2016-01-01

    Low-energy neutrons are playing a prominent role in a growing number of fundamental physics studies. This paper provides a brief description of the physics that some of the experiments in the area are addressing. (paper)

  7. Exploring the potential of the cosmic-ray neutron method to simultaneously predict soil water and vegetation dynamics

    Science.gov (United States)

    Bogena, H. R.; Fuchs, H.; Jakobi, J.; Huisman, J. A.; Diekkrüger, B.; Vereecken, H.

    2016-12-01

    Cosmic-ray neutron soil moisture probes are an emerging technology that rely on the negative correlation between near-surface fast neutron counts and soil moisture content since hydrogen atoms in the soil, which are mainly present as water, moderate the secondary neutrons on the way back to the surface. Any application of this method needs to consider the sensitivity of the neutron counts to additional sources of hydrogen (e.g. above- and below-ground biomass, humidity of the lower atmosphere, lattice water of the soil minerals, organic matter and water in the litter layer, intercepted water in the canopy, and soil organic matter). In this study, we analyzed the effects of temporally changing above- and below-ground biomass and intercepted water in the canopy on the cosmic-ray neutron counts and the calibration parameter N0. For this, two arable fields cropped with winter wheat and sugar beet were instrumented with several cosmic-ray neutron probes and a wireless sensor network with more than 200 in-situ soil moisture sensors. In addition, we measured rainfall interception in the wheat canopy at several locations in the field using totalisators and leaf wetness sensors. In order to track the changes in above- and below-ground biomass, roots and plants were sampled approximately every four weeks and LAI was measured weekly during the growing season. Weekly biomass changes were derived by relating LAI to total biomass. As expected, we found an increasing discrepancy between cosmic-ray-derived and in-situ measured soil moisture during the growing season and a sharp decrease in discrepancy after the harvest. In order to quantify the effect of hydrogen stored in the vegetation on fast neutron intensity, we derived time series of the calibration parameter N0 using a weekly moving-window optimization. We found a linear negative relationship between N0 and total fresh biomass and N0 and intercepted precipitation. Using these relationships for the correction of fast neutron

  8. 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

  9. 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

  10. Improving calibration and validation of cosmic-ray neutron sensors in the light of spatial sensitivity

    Directory of Open Access Journals (Sweden)

    M. Schrön

    2017-10-01

    Full Text Available In the last few years the method of cosmic-ray neutron sensing (CRNS has gained popularity among hydrologists, physicists, and land-surface modelers. The sensor provides continuous soil moisture data, averaged over several hectares and tens of decimeters in depth. However, the signal still may contain unidentified features of hydrological processes, and many calibration datasets are often required in order to find reliable relations between neutron intensity and water dynamics. Recent insights into environmental neutrons accurately described the spatial sensitivity of the sensor and thus allowed one to quantify the contribution of individual sample locations to the CRNS signal. Consequently, data points of calibration and validation datasets are suggested to be averaged using a more physically based weighting approach. In this work, a revised sensitivity function is used to calculate weighted averages of point data. The function is different from the simple exponential convention by the extraordinary sensitivity to the first few meters around the probe, and by dependencies on air pressure, air humidity, soil moisture, and vegetation. The approach is extensively tested at six distinct monitoring sites: two sites with multiple calibration datasets and four sites with continuous time series datasets. In all cases, the revised averaging method improved the performance of the CRNS products. The revised approach further helped to reveal hidden hydrological processes which otherwise remained unexplained in the data or were lost in the process of overcalibration. The presented weighting approach increases the overall accuracy of CRNS products and will have an impact on all their applications in agriculture, hydrology, and modeling.

  11. Improving calibration and validation of cosmic-ray neutron sensors in the light of spatial sensitivity

    Science.gov (United States)

    Schrön, Martin; Köhli, Markus; Scheiffele, Lena; Iwema, Joost; Bogena, Heye R.; Lv, Ling; Martini, Edoardo; Baroni, Gabriele; Rosolem, Rafael; Weimar, Jannis; Mai, Juliane; Cuntz, Matthias; Rebmann, Corinna; Oswald, Sascha E.; Dietrich, Peter; Schmidt, Ulrich; Zacharias, Steffen

    2017-10-01

    In the last few years the method of cosmic-ray neutron sensing (CRNS) has gained popularity among hydrologists, physicists, and land-surface modelers. The sensor provides continuous soil moisture data, averaged over several hectares and tens of decimeters in depth. However, the signal still may contain unidentified features of hydrological processes, and many calibration datasets are often required in order to find reliable relations between neutron intensity and water dynamics. Recent insights into environmental neutrons accurately described the spatial sensitivity of the sensor and thus allowed one to quantify the contribution of individual sample locations to the CRNS signal. Consequently, data points of calibration and validation datasets are suggested to be averaged using a more physically based weighting approach. In this work, a revised sensitivity function is used to calculate weighted averages of point data. The function is different from the simple exponential convention by the extraordinary sensitivity to the first few meters around the probe, and by dependencies on air pressure, air humidity, soil moisture, and vegetation. The approach is extensively tested at six distinct monitoring sites: two sites with multiple calibration datasets and four sites with continuous time series datasets. In all cases, the revised averaging method improved the performance of the CRNS products. The revised approach further helped to reveal hidden hydrological processes which otherwise remained unexplained in the data or were lost in the process of overcalibration. The presented weighting approach increases the overall accuracy of CRNS products and will have an impact on all their applications in agriculture, hydrology, and modeling.

  12. Monitoring Landscape Scale Soil Water Content with Cosmic-Ray Neutron Sensors: Validation and Calibration

    International Nuclear Information System (INIS)

    Wahbi, Ammar; Avery, William A.; Dercon, Gerd; Heng, Lee; Weltin, Georg; Franz, Trenton E.; Strauss, Peter; Oismueller, Markus; Desilets, Darin

    2017-01-01

    Increasing populations growth combined with climate change are putting pressure on water resources and agricultural systems around the world. The need for effective water management strategies designed to maximize water use efficiency has made access to soil water content (SWC) information crucial to the global community. This work builds upon ongoing research that began in December 2013 in which a stationary Cosmic-Ray Neutron Sensor (CRNS) was used to monitor SWC within an agricultural system located in north central Austria. Past work at this study site at Petzenkirchen, Austria (100 km west of Vienna) has focused on the calibration and validation of the CRNS technology, and has shown the CRNS to reliably estimate SWC on a large scale (circle with radius of cca. 250 m) when compared to other methods of estimating SWC. This was determined via comparisons of insitu soil sampling, time domain reflectometry (TDR), and time domain transmissivity (TDT) of SWC with estimates of SWC determined from the CRNS. However, questions remain regarding the effective use of the CRNS technology.

  13. Validation of SMAP Root Zone Soil Moisture Estimates with Improved Cosmic-Ray Neutron Probe Observations

    Science.gov (United States)

    Babaeian, E.; Tuller, M.; Sadeghi, M.; Franz, T.; Jones, S. B.

    2017-12-01

    Soil Moisture Active Passive (SMAP) soil moisture products are commonly validated based on point-scale reference measurements, despite the exorbitant spatial scale disparity. The difference between the measurement depth of point-scale sensors and the penetration depth of SMAP further complicates evaluation efforts. Cosmic-ray neutron probes (CRNP) with an approximately 500-m radius footprint provide an appealing alternative for SMAP validation. This study is focused on the validation of SMAP level-4 root zone soil moisture products with 9-km spatial resolution based on CRNP observations at twenty U.S. reference sites with climatic conditions ranging from semiarid to humid. The CRNP measurements are often biased by additional hydrogen sources such as surface water, atmospheric vapor, or mineral lattice water, which sometimes yield unrealistic moisture values in excess of the soil water storage capacity. These effects were removed during CRNP data analysis. Comparison of SMAP data with corrected CRNP observations revealed a very high correlation for most of the investigated sites, which opens new avenues for validation of current and future satellite soil moisture products.

  14. Intercomparison of cosmic-ray neutron sensors and water balance monitoring in an urban environment

    Science.gov (United States)

    Schrön, Martin; Zacharias, Steffen; Womack, Gary; Köhli, Markus; Desilets, Darin; Oswald, Sascha E.; Bumberger, Jan; Mollenhauer, Hannes; Kögler, Simon; Remmler, Paul; Kasner, Mandy; Denk, Astrid; Dietrich, Peter

    2018-03-01

    Sensor-to-sensor variability is a source of error common to all geoscientific instruments that needs to be assessed before comparative and applied research can be performed with multiple sensors. Consistency among sensor systems is especially critical when subtle features of the surrounding terrain are to be identified. Cosmic-ray neutron sensors (CRNSs) are a recent technology used to monitor hectometre-scale environmental water storages, for which a rigorous comparison study of numerous co-located sensors has not yet been performed. In this work, nine stationary CRNS probes of type CRS1000 were installed in relative proximity on a grass patch surrounded by trees, buildings, and sealed areas. While the dynamics of the neutron count rates were found to be similar, offsets of a few percent from the absolute average neutron count rates were found. Technical adjustments of the individual detection parameters brought all instruments into good agreement. Furthermore, we found a critical integration time of 6 h above which all sensors showed consistent dynamics in the data and their RMSE fell below 1 % of gravimetric water content. The residual differences between the nine signals indicated local effects of the complex urban terrain on the scale of several metres. Mobile CRNS measurements and spatial simulations with the URANOS neutron transport code in the surrounding area (25 ha) have revealed substantial sub-footprint heterogeneity to which CRNS detectors are sensitive despite their large averaging volume. The sealed and constantly dry structures in the footprint furthermore damped the dynamics of the CRNS-derived soil moisture. We developed strategies to correct for the sealed-area effect based on theoretical insights about the spatial sensitivity of the sensor. This procedure not only led to reliable soil moisture estimation during dry-out periods, it further revealed a strong signal of intercepted water that emerged over the sealed surfaces during rain events. The

  15. 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.)

  16. Measurement of the energy spectrum of cosmic-ray induced neutrons aboard an ER-2 high-altitude airplane

    CERN Document Server

    Goldhagen, P E; Kniss, T; Reginatto, M; Singleterry, R C; Van Steveninck, W; Wilson, J W

    2002-01-01

    Crews working on present-day jet aircraft are a large occupationally exposed group with a relatively high average effective dose from galactic cosmic radiation. Crews of future high-speed commercial aircraft flying at higher altitudes would be even more exposed. To help reduce the significant uncertainties in calculations of such exposures, the atmospheric ionizing radiation (AIR) project, an international collaboration of 15 laboratories, made simultaneous radiation measurements with 14 instruments on five flights of a NASA ER-2 high-altitude aircraft. The primary AIR instrument was a highly sensitive extended-energy multisphere neutron spectrometer with lead and steel shells placed within the moderators of two of its 14 detectors to enhance response at high energies. Detector responses were calculated for neutrons and charged hadrons at energies up to 100 GeV using MCNPX. Neutron spectra were unfolded from the measured count rates using the new MAXED code. We have measured the cosmic-ray neutron spectrum (t...

  17. Using Cosmic-Ray Neutron Probes to Monitor Landscape Scale Soil Water Content in Mixed Land Use Agricultural Systems

    International Nuclear Information System (INIS)

    Franz, Trenton E.; Wahbi, Ammar; Weltin, Georg; Heng, Lee; Dercon, Gerd; Vreugdenhi, Mariette; Oismueller, Markus; Strauss, Peter; Desilets, Darin

    2016-01-01

    With an ever-increasing demand for natural resources and the societal need to understand and predict natural disasters such as flood, soil water content (SWC) observations remain a critical variable to monitor in order to optimally allocate resources, establish early warning systems, and improve weather forecasts. However, routine agricultural production practices of soil cultivation, planting, and harvest make the operation and maintenance of direct contact point sensors for long-term monitoring a challenging task. In this work, we used Cosmic-Ray Neutron Probe (CRNP) to monitor landscape average SWC in a mixed agricultural land use system in northeast Austria since December 2013.

  18. 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.

  19. Sequential measurements of cosmic-ray neutron spectrum and dose rate at sea level in Sendai, Japan

    International Nuclear Information System (INIS)

    Nakamura, Takashi; Nunomiya, Tomoya; Abe, Shigeru; Terunuma, Kazutaka; Suzuki, Hiroyuki

    2005-01-01

    The cosmic-ray neutron energy spectrum and dose rate were measured sequentially for two years from April 2001 up to March 2003 by using three neutron detectors, a 3 He-loaded multi-moderator detector (Bonner ball), 12.7 cm diameter by 12.7 cm long NE213 organic liquid scintillator, and high-sensitivity rem (dose equivalent) counter at the Kawauchi campus of Tohoku University in Sendai, Japan of geomagnetic latitude, 29degN, and cutoff rigidity, 10.43 GV. The neutron spectrum has three major peaks, thermal energy peak, evaporation peak around 1 MeV and cascade peak around 100 MeV. The ambient neutron dose equivalent rates measured by the rem counter, and the Bonner ball keep almost constant values of 4.0 and 6.5 (nSv/h), respectively, throughout this time period, after atmospheric pressure correction, and it often decreased about 30% after a large Solar Flare, that is called as the Forbush decrease. The total neutron flux was also obtained by the Bonner ball measurements to be 7.5x10 -3 (ncm -2 ·s -1 ) in average. The altitude variation of neutron flux and dose was also investigated by comparing the measured results with other results measured at Mt. Fuji area and aboard an airplane, where the cutoff rigidities are similar. (author)

  20. Soil Moisture Estimation Across Scales with Mobile Sensors for Cosmic-Ray Neutrons from the Ground and Air

    Science.gov (United States)

    Schrön, Martin; Köhler, Mandy; Bannehr, Lutz; Köhli, Markus; Fersch, Benjamin; Rebmann, Corinna; Mai, Juliane; Cuntz, Matthias; Kögler, Simon; Schröter, Ingmar; Wollschläger, Ute; Oswald, Sascha; Dietrich, Peter; Zacharias, Steffen

    2016-04-01

    Soil moisture is a key variable for environmental sciences, but its determination at various scales and depths is still an open challenge. Cosmic-ray neutron sensing has become a well accepted and unique method to monitor an effective soil water content, covering tens of hectares in area and tens of centimeters in depth. The technology is famous for its low maintanance, non-invasiveness, continous measurement, and most importantly its large footprint and penetration depth. Beeing more representative than point data, and finer resolved plus deeper penetrating than remote-sensing products, cosmic-ray neutron derived soil moisture products provide unrivaled advantage for agriculture, regional hydrologic and land surface models. The method takes advantage of omnipresent neutrons which are extraordinarily sensitive to hydrogen in soil, plants, snow and air. Unwanted hydrogen sources in the footprint can be excluded by local calibration to extract the pure soil water information. However, this procedure is not feasible for mobile measurements, where neutron detectors are mounted on a car to do catchment-scale surveys. As a solution to that problem, we suggest strategies to correct spatial neutron data with the help of available spatial data of soil type, landuse and vegetation. We further present results of mobile rover campaigns at various scales and conditions, covering small sites from 0.2 km2 to catchments of 100 km2 area, and complex terrain from agricultural fields, urban areas, forests, to snowy alpine sites. As the rover is limited to accessible roads, we further investigated the applicability of airborne measurements. First tests with a gyrocopter at 150 to 200m heights proofed the concept of airborne neutron detection for environmental sciences. Moreover, neutron transport simulations confirm an improved areal coverage during these campaigns. Mobile neutron measurements at the ground or air are a promising tool for the detection of water sources across many

  1. 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.

  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. 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)

  4. High-altitude cosmic ray neutrons: probable source for the high-energy protons of the earth's radiation belts

    International Nuclear Information System (INIS)

    Hajnal, F.; Wilson, J.

    1992-01-01

    'Full Text:' Several High-altitude cosmic-ray neutron measurements were performed by the NASA Ames Laboratory in the mid-to late-1970s using airplanes flying at about 13km altitude along constant geomagnetic latitudes of 20, 44 and 51 degrees north. Bonner spheres and manganese, gold and aluminium foils were used in the measurements. In addition, large moderated BF-3 counters served as normalizing instruments. Data analyses performed at that time did not provide complete and unambiguous spectral information and field intensities. Recently, using our new unfolding methods and codes, and Bonner-sphere response function extensions for higher energies, 'new' neutron spectral intensities were obtained, which show progressive hardening of neutron spectra as a function of increasing geomagnetic latitude, with substantial increases in the energy region iron, 1 0 MeV to 10 GeV. For example, we found that the total neutron fluences at 20 and 51 degrees magnetic north are in the ratio of 1 to 5.2 and the 10 MeV to 10 GeV fluence ratio is 1 to 18. The magnitude of these ratios is quite remarkable. From the new results, the derived absolute neutron energy distribution is of the correct strength and shape for the albedo neutrons to be the main source of the high-energy protons trapped in the Earth's inner radiation belt. In addition, the results, depending on the extrapolation scheme used, indicate that the neutron dose equivalent rate may be as high as 0.1 mSv/h near the geomagnetic north pole and thus a significant contributor to the radiation exposures of pilots, flight attendants and the general public. (author)

  5. Cosmic-ray-induced sup 6 sup 3 Ni -A potential confounder of fast-neutron-induced sup 6 sup 3 Ni in copper samples from Hiroshima

    CERN Document Server

    Rühm, W; Wallner, A; Fästermann, T; Knie, K; Heisinger, B; Nolte, E; Korschinek, G; Marchetti, A A; Martinelli, R E; Carroll, K L

    2003-01-01

    Recently, the determination of sup 6 sup 3 Ni in copper samples has been suggested as a means to assess fast-neutron fluences in Hiroshima and Nagasaki. In those samples, sup 6 sup 3 Ni (half-life: 100.07 years) was produced by MeV neutrons from the A-bomb explosions via the reaction sup 6 sup 3 Cu(n,p) sup 6 sup 3 Ni. For large distances from the hypocenters, cosmic-ray-induced production of sup 6 sup 3 Ni might also be important and, therefore, it is calculated here. The effective probability f sup * which is required to quantify the cosmic-ray-induced production by stopped muons, was measured, and a value of (12.6 +-1.6)% obtained. The cross-section for the cosmic-ray-induced production by fast muons was measured to be (0.64 +-0.33) mb, at a muon energy of 100 GeV. To validate the proposed method, cosmic-ray-induced production of sup 3 sup 2 P in sulfur and of sup 3 sup 9 Ar in granite was also calculated, and reasonable agreement with literature values was found. Our estimates indicate that as many as (4 ...

  6. Cosmic Rays and Dynamical Meteorology, 2. Snow Effect In Different Multiplicities According To Neutron Monitor Data of Emilio Segre' Observatory

    Science.gov (United States)

    Dorman, L. I.; Iucci, N.; Pustil'Nik, L. A.; Sternlieb, A.; Villoresi, G.; Zukerman, I. G.

    On the basis of cosmic ray hourly data obtained by NM of Emilio Segre' Observatory (hight 2025 m above s.l., cut-off rigidity for vertical direction 10.8 GV) we determine the snow effect in CR for total neutron intensity and for multiplicities m=1, m=2, m=3, m=4, m=5, m=6, and m=7. For comparison and excluding primary CR variations we use also hourly data on neutron multiplicities obtained by Rome NM (about sea level, cut-off rigidity 6.7 GV). In this paper we will analize effects of snow in periods from 4 January 2000 to 15 April 2000 with maximal absorption effect about 5%, and from 21 December 2000 up to 31 March 2001 with maximal effect 13% in the total neu- tron intensity. We use the periods without snow to determine regeression coefficients between primary CR variations observed by NM of Emilio Segre' Observatory, and by Rome NM. On the basis of obtained results we develop a method to correct data on snow effect by using several NM hourly data. On the basis of our data we estimate the accuracy with what can be made correction of NM data of stations where the snow effect can be important.

  7. DOUBLE-EXPONENTIAL FITTING FUNCTION FOR EVALUATION OF COSMIC-RAY-INDUCED NEUTRON FLUENCE RATE IN ARBITRARY LOCATIONS.

    Science.gov (United States)

    Li, Huailiang; Yang, Yigang; Wang, Qibiao; Tuo, Xianguo; Julian Henderson, Mark; Courtois, Jérémie

    2017-12-01

    The fluence rate of cosmic-ray-induced neutrons (CRINs) varies with many environmental factors. While many current simulation and experimental studies have focused mainly on the altitude variation, the specific rule that the CRINs vary with geomagnetic cutoff rigidity (which is related to latitude and longitude) was not well considered. In this article, a double-exponential fitting function F=(A1e-A2CR+A3)eB1Al, is proposed to evaluate the CRINs' fluence rate varying with geomagnetic cutoff rigidity and altitude. The fitting R2 can have a value up to 0.9954, and, moreover, the CRINs' fluence rate in an arbitrary location (latitude, longitude and altitude) can be easily evaluated by the proposed function. The field measurements of the CRINs' fluence rate and H*(10) rate in Mt. Emei and Mt. Bowa were carried out using a FHT-762 and LB 6411 neutron prober, respectively, and the evaluation results show that the fitting function agrees well with the measurement results. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. Cosmic-ray neutron transport at a forest field site: the sensitivity to various environmental conditions with focus on biomass and canopy interception

    Science.gov (United States)

    Andreasen, Mie; Jensen, Karsten H.; Desilets, Darin; Zreda, Marek; Bogena, Heye R.; Looms, Majken C.

    2017-04-01

    Cosmic-ray neutron intensity is inversely correlated to all hydrogen present in the upper decimeters of the subsurface and the first few hectometers of the atmosphere above the ground surface. This correlation forms the base of the cosmic-ray neutron soil moisture estimation method. The method is, however, complicated by the fact that several hydrogen pools other than soil moisture affect the neutron intensity. In order to improve the cosmic-ray neutron soil moisture estimation method and explore the potential for additional applications, knowledge about the environmental effect on cosmic-ray neutron intensity is essential (e.g., the effect of vegetation, litter layer and soil type). In this study the environmental effect is examined by performing a sensitivity analysis using neutron transport modeling. We use a neutron transport model with various representations of the forest and different parameters describing the subsurface to match measured height profiles and time series of thermal and epithermal neutron intensities at a field site in Denmark. Overall, modeled thermal and epithermal neutron intensities are in satisfactory agreement with measurements; however, the choice of forest canopy conceptualization is found to be significant. Modeling results show that the effect of canopy interception, soil chemistry and dry bulk density of litter and mineral soil on neutron intensity is small. On the other hand, the neutron intensity decreases significantly with added litter-layer thickness, especially for epithermal neutron energies. Forest biomass also has a significant influence on the neutron intensity height profiles at the examined field site, altering both the shape of the profiles and the ground-level thermal-to-epithermal neutron ratio. This ratio increases with increasing amounts of biomass, and was confirmed by measurements from three sites representing agricultural, heathland and forest land cover. A much smaller effect of canopy interception on the ground

  9. 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.

  10. Towards Hydrological Applications of Stationary and Roving Cosmic-Ray Neutron Sensors in the Light of Spatial Sensitivity

    Science.gov (United States)

    Schrön, M.; Köhli, M.; Rosolem, R.; Baroni, G.; Bogena, H. R.; Brenner, J.; Zink, M.; Rebmann, C.; Oswald, S. E.; Dietrich, P.; Samaniego, L. E.; Zacharias, S.

    2017-12-01

    Cosmic-Ray Neutron Sensing (CRNS) has become a promising and unique method to monitor water content at an effective scale of tens of hectares in area and tens of centimeters in depth. The large footprint is particularly beneficial for hydrological models that operate at these scales.However, reliable estimates of average soil moisture require a detailed knowledge about the sensitivity of the signal to spatial inhomogeneity within the footprint. From this perspective, the large integrating volume challenges data interpretation, validation, and calibration of the sensor. Can we still generate reliable data for hydrological applications? One of the top challenges in the last years was to find out where the signal comes from, and how sensitive it is to spatial variabilities of moisture. Neutron physics simulations have shown that the neutron signal represents a non-linearly weighted average of soil water in the footprint. With the help of the so-called spatial sensitivity functions it is now possible to quantify the contribution of certain regions to the neutron signal. We present examples of how this knowledge can help (1) to understand the contribution of irrigated and sealed areas in the footprint, (2) to improve calibration and validation of the method, and (3) to even reveal excess water storages, e.g. from ponding or rain interception.The spatial sensitivity concept can also explain the influence of dry roads on the neutron signal. Mobile surveys with the CRNS rover have been a common practice to measure soil moisture patterns at the kilometer scale. However, dedicated experiments across agricultural fields in Germany and England have revealed that field soil moisture is significantly underestimated when moving the sensor on roads. We show that knowledge about the spatial sensitivity helps to correct survey data for these effects, depending on road material, width, and distance from the road. The recent methodological advances allow for improved signal

  11. 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

  12. The energy spectrum of cosmic-ray induced neutrons measured on an airplane over a wide range of altitude and latitude

    International Nuclear Information System (INIS)

    Goldhagen, P.; Clem, J. M.; Wilson, J. W.

    2004-01-01

    Crews of high-altitude aircraft are exposed to radiation from galactic cosmic rays (GCRs). To help determine such exposures, the Atmospheric Ionizing Radiation Project, an international collaboration of 15 laboratories, made simultaneous radiation measurements with 14 instruments on a NASA ER-2 high-altitude airplane. The primary instrument was a sensitive extended-energy multisphere neutron spectrometer. Its detector responses were calculated for energies up to 100 GeV using the radiation transport code MCNPX 2.5.d with improved nuclear models and including the effects of the airplane structure. New calculations of GCR-induced particle spectra in the atmosphere were used to correct for spectrometer counts produced by protons, pions and light nuclear ions. Neutron spectra were unfolded from the corrected measured count rates using the deconvolution code MAXED 3.1. The results for the measured cosmic-ray neutron spectrum (thermal to >10 GeV), total neutron fluence rate, and neutron dose equivalent and effective dose rates, and their dependence on altitude and geomagnetic cut-off agree well with results from recent calculations of GCR-induced neutron spectra. (authors)

  13. 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

  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. 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.

  16. Airborne Detection of Cosmic-Ray Albedo Neutrons for Regional-Scale Surveys of Root-Zone Soil Water on Earth

    Science.gov (United States)

    Schrön, M.; Bannehr, L.; Köhli, M.; Zreda, M. G.; Weimar, J.; Zacharias, S.; Oswald, S. E.; Bumberger, J.; Samaniego, L. E.; Schmidt, U.; Zieger, P.; Dietrich, P.

    2017-12-01

    While the detection of albedo neutrons from cosmic rays became a standard method in planetary space science, airborne neutron sensing has never been conceived for hydrological research on Earth. We assessed the applicability of atmospheric neutrons to sense root-zone soil moisture averaged over tens of hectares using neutron detectors on an airborne vehicle. Large-scale quantification of near-surface water content is an urgent challenge in hydrology. Information about soil and plant water is crucial to accurately assess the risks for floods and droughts, to adjust regional weather forecasts, and to calibrate and validate the corresponding models. However, there is a lack of data at scales relevant for these applications. Most conventional ground-based geophysical instruments provide root-zone soil moisture only within a few tens of m2, while electromagnetic signals from conventional remote-sensing instruments can only penetrate the first few centimeters below surface, though at larger spatial areas.In the last couple of years, stationary and roving neutron detectors have been used to sense the albedo component of cosmic-ray neutrons, which represents the average water content within 10—15 hectares and 10—50 cm depth. However, the application of these instruments is limited by inaccessible terrain and interfering local effects from roads. To overcome these limitations, we have pioneered first simulations and experiments of such sensors in the field of airborne geophysics. Theoretical investigations have shown that the footprint increases substantially with height above ground, while local effects smooth out throughout the whole area. Campaigns with neutron detectors mounted on a lightweight gyrocopter have been conducted over areas of various landuse types including agricultural fields, urban areas, forests, flood plains, and lakes. The neutron signal showed influence of soil moisture patterns in heights of up to 180 m above ground. We found correlation with

  17. 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

  18. Status of the low energy neutron source at Indiana University

    International Nuclear Information System (INIS)

    Baxter, D.V.; Cameron, J.M.; Derenchuk, V.P.; Lavelle, C.M.; Leuschner, M.B.; Lone, M.A.; Meyer, H.O.; Rinckel, T.; Snow, W.M.

    2005-01-01

    The National Science Foundation has recently approved funding for LENS (the low energy neutron source) at Indiana University and construction of this facility has begun. LENS represents a new paradigm for economically introducing neutron scattering into a university or industrial setting. In this design, neutrons are produced in a long-pulse (1 ms) mode through (p,n) reactions on a water-cooled Be target and the target is tightly coupled to a cryogenic moderator with a water reflector. This design gives a facility suitable for materials research, the development of new neutron instrumentation, and the education of new neutron scientists

  19. Performance of the SciBar cosmic ray telescope (SciCRT) toward the detection of high-energy solar neutrons in solar cycle 24

    Science.gov (United States)

    Sasai, Yoshinori; Nagai, Yuya; Itow, Yoshitaka; Matsubara, Yutaka; Sako, Takashi; Lopez, Diego; Itow, Tsukasa; Munakata, Kazuoki; Kato, Chihiro; Kozai, Masayoshi; Miyazaki, Takahiro; Shibata, Shoichi; Oshima, Akitoshi; Kojima, Hiroshi; Tsuchiya, Harufumi; Watanabe, Kyoko; Koi, Tatsumi; Valdés-Galicia, Jose Francisco; González, Luis Xavier; Ortiz, Ernesto; Musalem, Octavio; Hurtado, Alejandro; Garcia, Rocio; Anzorena, Marcos

    2014-12-01

    We plan to observe solar neutrons at Mt. Sierra Negra (4,600 m above sea level) in Mexico using the SciBar detector. This project is named the SciBar Cosmic Ray Telescope (SciCRT). The main aims of the SciCRT project are to observe solar neutrons to study the mechanism of ion acceleration on the surface of the sun and to monitor the anisotropy of galactic cosmic-ray muons. The SciBar detector, a fully active tracker, is composed of 14,848 scintillator bars, whose dimension is 300 cm × 2.5 cm × 1.3 cm. The structure of the detector enables us to obtain the particle trajectory and its total deposited energy. This information is useful for the energy reconstruction of primary neutrons and particle identification. The total volume of the detector is 3.0 m × 3.0 m × 1.7 m. Since this volume is much larger than the solar neutron telescope (SNT) in Mexico, the detection efficiency of the SciCRT for neutrons is highly enhanced. We performed the calibration of the SciCRT at Instituto Nacional de Astrofisica, Optica y Electronica (INAOE) located at 2,150 m above sea level in Mexico in 2012. We installed the SciCRT at Mt. Sierra Negra in April 2013 and calibrated this detector in May and August 2013. We started continuous observation in March 2014. In this paper, we report the detector performance as a solar neutron telescope and the current status of the SciCRT.

  20. 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.)

  1. 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

  2. 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.)

  3. 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.

  4. 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). )

  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. 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)

  7. Cosmic Ray Studies with IceCube

    Science.gov (United States)

    Gonzalez, Javier

    In this contribution we will give an overview of the cosmic ray studies conducted within the IceCube collaboration. The IceCube detector in the geographical south pole can be used to measure various characteristics of the extensive air showers induced by high energy cosmic rays. With IceTop, the surface component of the detector, we detect the electromagnetic and muon components of the air showers, while with the deep detector we detect the high energy muons. We have measured the energy spectrum of cosmic ray primaries in the range between 1.58PeV and 1.26 EeV. A combined analysis of the high energy muon bundles in the ice and the air shower footprint in IceTop provides a measure of primary composition. We will also discuss how the sensitivity to low energy muons in the air showers has the potential to produce additional measures of primary composition.

  8. 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...

  9. 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

  10. 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)

  11. Department of Cosmic Ray Physics - Overview

    International Nuclear Information System (INIS)

    Szabelski, J.

    2010-01-01

    experimentally the problems of mass composition and EAS. development in the atmosphere in the energy range 10 15 - 1- 18 eV. Knowledge of the mass composition would contribute to models and the search for Cosmic Ray astrophysical sources. The interaction models in the simulation code CORSIKA play an essential role in the interpretation of the data. These are studied experimentally using the KASCADE hadron calorimeter and by measuring EAS muon directions and lateral distributions. The LOPES Collaboration is developing radio techniques for EAS measurements in Karlsruhe. · Locally in Lodz we concentrate on methodological studies of the detection of neutrons and the interpretation of multiple neutron registrations in the underground laboratory. By examining EAS data it is possible to study some properties of very high energy interactions. Detectors at the recently started LHC could verify the models used in the EAS simulations. In the area of high energy particle physics the Department participates in the ZEUS experiment at DESY (Hamburg, Germany), and in the WASA at COSY Collaboration in Juelich, Germany. (author)

  12. 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

  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. 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.

  16. 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...

  17. 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)

  18. Fusion reaction using low energy neutron-excess nucleus beam

    International Nuclear Information System (INIS)

    Fukuda, Tomokazu

    1994-01-01

    The present state and the plan of the experiment of measuring the fusion reaction near barriers by using neutron-excess nucleus beam, which has been advanced at RIKEN are reported. One of the purposes of this experiment is the feasibility investigation of the fusion reaction by using neutron-excess nuclei, which is indispensable for synthesizing superheavy elements. It is intended to systematically explore some enhancing mechanism in the neutron-excess nuclei which are unfavorable in beam intensity. This research can become the good means to prove the dynamic behavior of the neutrons on the surfaces of nuclei in reaction. The fusion reaction of 27 Al + Au was measured by using the stable nucleus beam of 27 Al, and the results are shown. In order to know the low energy fusion reaction of 11 Li and 11 Be which are typical halo nuclei, the identification by characteristic α ray of composite nuclei is carried out in 7,9,11 Li + 209 Bi and 9,10,11 Be + 208 Pb. A new detector having high performance, New MUSIC, is being developed. As the experiment by using this detector, the efficient measurement of the fusion reaction by using heavy neutron-excess nuclei up to Ni is considered. An example of 8 Li + α → 11 B + n reaction for celestial body physics is mentioned. (K.I.)

  19. Footprint radius of a cosmic-ray neutron probe for measuring soil-water content and its spatiotemporal variability in an alpine meadow ecosystem

    Science.gov (United States)

    Zhu, Xuchao; Cao, Ruixue; Shao, Mingan; Liang, Yin

    2018-03-01

    Cosmic-ray neutron probes (CRNPs) have footprint radii for measuring soil-water content (SWC). The theoretical radius is much larger at high altitude, such as the northern Tibetan Plateau, than the radius at sea level. The most probable practical radius of CRNPs for the northern Tibetan Plateau, however, is not known due to the lack of SWC data in this hostile environment. We calculated the theoretical footprint of the CRNP based on a recent simulation and analyzed the practical radius of a CRNP for the northern Tibetan Plateau by measuring SWC at 113 sampling locations on 21 measuring occasions to a depth of 30 cm in a 33.5 ha plot in an alpine meadow at 4600 m a.s.l. The temporal variability and spatial heterogeneity of SWC within the footprint were then analyzed. The theoretical footprint radius was between 360 and 420 m after accounting for the influences of air humidity, soil moisture, vegetation and air pressure. A comparison of SWCs measured by the CRNP and a neutron probe from access tubes in circles with different radii conservatively indicated that the most probable experimental footprint radius was >200 m. SWC within the CRNP footprint was moderately variable over both time and space, but the temporal variability was higher. Spatial heterogeneity was weak, but should be considered in future CRNP calibrations. This study provided theoretical and practical bases for the application and promotion of CRNPs in alpine meadows on the Tibetan Plateau.

  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. Cosmic ray antimatter: Is it primary or secondary?

    Science.gov (United States)

    Stecker, F. W.; Protheroe, R. J.; Kazanas, D.

    1981-01-01

    The relative merits and difficulties of the primary and secondary origin hypotheses for the observed cosmic ray antiprotons, including the low energy measurement of Buffington, were examined. It is concluded that the cosmic ray antiproton data may be strong evidence for antimatter galaxies and baryon symmetric cosmology. The present antiproton data are consistent with a primary extragalactic component having antiproton/proton approximately equal to .0032 + or - 0.7.

  2. Cosmic-ray exposure records and origins of meteorites

    International Nuclear Information System (INIS)

    Reedy, R.C.

    1985-01-01

    The cosmic-ray records of meteorites can be used to infer much about their origins and recent histories. Some meteorites had simple cosmic-ray exposure histories, while others had complex exposure histories with their cosmogenic products made both before and after a collision in space. The methods used to interpret meteorites' cosmic-ray records, especially identifying simple or complex exposure histories, often are inadequate. Besides spallogenic radionuclides and stable nuclides, measurements of products that have location-sensitive production rates, such as the tracks of heavy cosmic-ray nuclei or neutron-capture nuclides, are very useful in accurately determining a meteorite's history. Samples from different, known locations of a meteorite help in studying the cosmic-ray record. Such extensive sets of meteorite measurements, plus theoretical modeling of complex histories, will improve our ability to predict the production of cosmogenic nuclides in meteorites, to distinguish simple and complex exposure histories, and to better determine exposure ages

  3. Cosmic Rays in the Heliosphere: Requirements for Future Observations

    Science.gov (United States)

    Mewaldt, R. A.

    2013-06-01

    Since the publication of Cosmic Rays in the Heliosphere in 1998 there has been great progress in understanding how and why cosmic rays vary in space and time. This paper discusses measurements that are needed to continue advances in relating cosmic ray variations to changes in solar and interplanetary activity and variations in the local interstellar environment. Cosmic ray acceleration and transport is an important discipline in space physics and astrophysics, but it also plays a critical role in defining the radiation environment for humans and hardware in space, and is critical to efforts to unravel the history of solar activity. Cosmic rays are measured directly by balloon-borne and space instruments, and indirectly by ground-based neutron, muon and neutrino detectors, and by measurements of cosmogenic isotopes in ice cores, tree-rings, sediments, and meteorites. The topics covered here include: what we can learn from the deep 2008-2009 solar minimum, when cosmic rays reached the highest intensities of the space era; the implications of 10Be and 14C isotope archives for past and future solar activity; the effects of variations in the size of the heliosphere; opportunities provided by the Voyagers for discovering the origin of anomalous cosmic rays and measuring cosmic-ray spectra in interstellar space; and future space missions that can continue the exciting exploration of the heliosphere that has occurred over the past 50 years.

  4. Assessment of the soil water balance by the combination of cosmic ray neutron sensing and eddy covariance technique in an irrigated citrus orchard (Marrakesh, Morocco)

    Science.gov (United States)

    Mroos, Katja; Baroni, Gabriele; Er-Raki, Salah; Francke, Till; Khabba, Said; Jarlan, Lionel; Hanich, Lahoucine; Oswald, Sascha E.

    2014-05-01

    Irrigation water requirement plays a crucial role in many agricultural areas and especially in arid and semi-arid landscapes. Improvements in the water management and the performance of the irrigation systems require a correct evaluation of the hydrological processes involved. However, some difficulties can arise due to the heterogeneity of the soil-plant system and of the irrigation scheme. To overcome these limitations, in this study, the soil water balance is analyzed by the combination of the Eddy Covariance technique (EC) and Cosmic Ray neutron Sensing (CRS). EC provides the measurement of the actual evapotranspiration over the area as it was presented in many field conditions. Moreover CRS showed to be a valuable approach to measure the root zone soil moisture integrated in a footprint of ~30 ha. In this way, the combination of the two methodologies should provide a better analysis of the soil water balance at field scale, as opposed to point observations, e.g. by TDR, evaporimeter and fluxmeter. Then, this could increase the capability to assess the irrigation efficiency and the agricultural water management. The study is conducted in a citrus orchard situated in a semi-arid region, 30 km southwest of Marrakesh (Morocco). The site is flat and planted with trees of same age growing in parallel rows with drip irrigation lines and application of fertilizer and pesticides. The original soil seems modified on the surface by the agricultural use, creating differences between trees, rows and lines. In addition, the drip irrigation creates also a spatial variability of the water flux distribution in the field, making this site an interesting area to test the methodology. Particular attention is given to the adaptation of the standard soil sampling campaign used for the calibration of the CRS and the introduction of a weighing function. Data were collected from June to December 2013, which corresponds to the high plant transpiration. Despite the intention of the

  5. 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)

  6. 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

    identify and classify SPS. A worldwide network of cosmic-ray detectors could not only become a unique tool to study fundamental physics, it will also provide a number of other opportunities, including space-weather or geophysics studies. Among the latter one has to list the potential to predict earthquakes by monitoring the rate of low energy cosmic-ray events. The diversity of goals motivates us to advertise this concept across the astroparticle physics community.

  7. 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

  8. 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

  9. 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

  10. 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

  11. Activation measurements for fast neutrons. Part D. Evaluation of cosmic-ray-induced 63Ni background in copper

    International Nuclear Information System (INIS)

    Ruehm, Werner; Rugel, Georg; Faestermann, Thomas

    2005-01-01

    As a result of a joint collaboration between the University of Utah, LLNL, the Technical University Munich and the Ludwig Maximilians University Munich, it became possible to determine A-bomb induced 63 Ni in pure copper samples from Hiroshima beyond a ground range of 1,000 m (see Chapter 9, Part B). The low 63 Ni activities induced in copper samples due to neutrons from the A-bomb explosion at large distance require, however, a careful discussion of the fraction of 63 Ni produced in these samples due to cosmic radiation. In this section, an analysis of the production of 63 Ni in copper samples due to cosmic radiation is performed. Production due to neutrons, protons, stopped muons, and photonuclear reactions is discussed. It is obvious from Figure 1 (Pfennig et al. 1995) that a variety of reactions induced by neutrons, protons, muons and photons can contribute to the production of 63 Ni in copper. The most important of these processes will be discussed here. Since the cross-sections for the production of 63 Ni in copper samples due to fast and stopped muons were not known, they were determined experimentally. (J.P.N.)

  12. 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)

  13. 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...

  14. 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...

  15. 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

  16. 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

  17. 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.

  18. 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

  19. Cosmic-ray exposure records and origins of meteorites

    International Nuclear Information System (INIS)

    Reedy, R.C.

    1985-01-01

    The cosmic-ray records of meteorites are used to infer much about their origins and recent histories. The methods used to interpret meteorites cosmic-ray records, especially identifying simple or complex exposure histories, often are inadequate. Spallogenic radionuclides, stable nuclides, and measurements of products that have location-sensitive production rates, such as the tracks of heavy cosmic-ray nuclei or neutron-capture nuclides, are very useful in accurately determining a meteorite's history. Samples from different, known locations of a meteorite help in studying the cosmic-ray record. Such extensive sets of meteorite measuremetns, plus theoretical modeling of complex histories, improves the ability to predict the production of cosmogenic nuclides in meteorites, to distinguish simple and complex exposure histories, and to better determine exposure ages

  20. 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...

  1. 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.)

  2. 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.

  3. Cosmic Ray Background Analysis For A Cargo Container Counter

    International Nuclear Information System (INIS)

    Ensslin, Norbert; Geist, W.H.; Lestone, J.P.; Mayo, D.R.; Menlove, Howard O.

    2001-01-01

    We have developed a new model for calculating the expected yield of cosmic-ray spallation neutrons in a Cargo Container Counter, and we have benchmarked the model against measurements made with several existing large neutron counters. We also developed two versions of a new measurement uncertainty prediction code based on Microsoft Excel spreadsheets. The codes calculate the minimum detectability limit for the Cargo Container Counter for either neutron singles or doubles counting, and also propagate the uncertainties associated with efficiency normalization flux monitors and cosmic ray flux monitors. This paper will describe the physics basis for this analysis, and the results obtained for several different counter designs.

  4. 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....

  5. COSMOS: the COsmic-ray Soil Moisture Observing System

    Directory of Open Access Journals (Sweden)

    M. Zreda

    2012-11-01

    Full Text Available The newly-developed cosmic-ray method for measuring area-average soil moisture at the hectometer horizontal scale is being implemented in the COsmic-ray Soil Moisture Observing System (or the COSMOS. The stationary cosmic-ray soil moisture probe measures the neutrons that are generated by cosmic rays within air and soil and other materials, moderated by mainly hydrogen atoms located primarily in soil water, and emitted to the atmosphere where they mix instantaneously at a scale of hundreds of meters and whose density is inversely correlated with soil moisture. The COSMOS has already deployed more than 50 of the eventual 500 cosmic-ray probes, distributed mainly in the USA, each generating a time series of average soil moisture over its horizontal footprint, with similar networks coming into existence around the world. This paper is written to serve a community need to better understand this novel method and the COSMOS project. We describe the cosmic-ray soil moisture measurement method, the instrument and its calibration, the design, data processing and dissemination used in the COSMOS project, and give example time series of soil moisture obtained from COSMOS probes.

  6. Do cosmic ray air showers initiate lightning? : A statistical analysis of cosmic ray air showers and lightning mapping array data

    NARCIS (Netherlands)

    Hare, B. M.; Dwyer, J. R.; Winner, L. H.; Uman, M. A.; Jordan, D. M.; Kotovsky, D. A.; Caicedo, J. A.; Wilkes, R. A.; Carvalho, F. L.; Pilkey, J. T.; Ngin, T. K.; Gamerota, W. R.; Rassoul, H. K.

    2017-01-01

    It has been argued in the technical literature, and widely reported in the popular press, that cosmic ray air showers (CRASs) can initiate lightning via a mechanism known as relativistic runaway electron avalanche (RREA), where large numbers of high-energy and low-energy electrons can, somehow,

  7. 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.

  8. THE IMPLICATIONS OF A HIGH COSMIC-RAY IONIZATION RATE IN DIFFUSE INTERSTELLAR CLOUDS

    International Nuclear Information System (INIS)

    Indriolo, Nick; Fields, Brian D.; McCall, Benjamin J.

    2009-01-01

    Diffuse interstellar clouds show large abundances of H + 3 which can only be maintained by a high ionization rate of H 2 . Cosmic rays are the dominant ionization mechanism in this environment, so the large ionization rate implies a high cosmic-ray flux, and a large amount of energy residing in cosmic rays. In this paper, we find that the standard propagated cosmic-ray spectrum predicts an ionization rate much lower than that inferred from H + 3 . Low-energy (∼10 MeV) cosmic rays are the most efficient at ionizing hydrogen, but cannot be directly detected; consequently, an otherwise unobservable enhancement of the low-energy cosmic-ray flux offers a plausible explanation for the H + 3 results. Beyond ionization, cosmic rays also interact with the interstellar medium by spalling atomic nuclei and exciting atomic nuclear states. These processes produce the light elements Li, Be, and B, as well as gamma-ray lines. To test the consequences of an enhanced low-energy cosmic-ray flux, we adopt two physically motivated cosmic-ray spectra which by construction reproduce the ionization rate inferred in diffuse clouds, and investigate the implications of these spectra on dense cloud ionization rates, light-element abundances, gamma-ray fluxes, and energetics. One spectrum proposed here provides an explanation for the high ionization rate seen in diffuse clouds while still appearing to be broadly consistent with other observables, but the shape of this spectrum suggests that supernovae remnants may not be the predominant accelerators of low-energy cosmic rays.

  9. Recent developments in very low energy neutron technology

    International Nuclear Information System (INIS)

    Utsuro, Masahiko; Kawabata, Yuji; Yamaguchi, Akira; Yoshiki, Hajime.

    1993-01-01

    In this report, the recent state of the research and technical development of the neutrons in the energy region below 0.5 meV is introduced. The neutrons in this region are further divided into very cold neutrons (VCN) and ultracold neutrons (UCN). The UCNs are known by such characteristic behavior that they can be confined in a neutron bottle for long time. The attempt to verify the break of T conversion symmetry using neutrons is carried out. The experiment to show the break of T conversion symmetry by grasping the asymmetry of particle emission accompanying the beta decay of polarized neutrons is conceivable. In these cases, the use of UCNs in neutron bottles is effective. The optical properties of VCNs and UCNs are peculiar and resemble to those of light. The only VCN source in Japan is installed in the liquid deuterium CN source in the graphite facility of the KUR. VCNs are taken out from the reactor, and are converted to UCNs using a neutron turbine. The characteristics of an UCN bottle were measured, and the life of neutrons was determined as 887.6 ± 3s. The UCN experiment using superfluid helium was carried out, and the application of gravity to UCN spectrometry was developed as NESSIE. (K.I.)

  10. 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...

  11. 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...

  12. 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.

  13. 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

  14. 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.

  15. Low energy neutron background in deep underground laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Best, Andreas, E-mail: andreas.best@lngs.infn.it [INFN, Laboratori Nazionali del Gran Sasso (LNGS), 67100 Assergi (Italy); Department of Physics and The Joint Institute for Nuclear Astrophysics, University of Notre Dame, Notre Dame, IN 46556 (United States); Görres, Joachim [Department of Physics and The Joint Institute for Nuclear Astrophysics, University of Notre Dame, Notre Dame, IN 46556 (United States); Junker, Matthias [INFN, Laboratori Nazionali del Gran Sasso (LNGS), 67100 Assergi (Italy); Kratz, Karl-Ludwig [Department for Biogeochemistry, Max-Planck-Institute for Chemistry, 55020 Mainz (Germany); Laubenstein, Matthias [INFN, Laboratori Nazionali del Gran Sasso (LNGS), 67100 Assergi (Italy); Long, Alexander [Department of Physics and The Joint Institute for Nuclear Astrophysics, University of Notre Dame, Notre Dame, IN 46556 (United States); Nisi, Stefano [INFN, Laboratori Nazionali del Gran Sasso (LNGS), 67100 Assergi (Italy); Smith, Karl; Wiescher, Michael [Department of Physics and The Joint Institute for Nuclear Astrophysics, University of Notre Dame, Notre Dame, IN 46556 (United States)

    2016-03-11

    The natural neutron background influences the maximum achievable sensitivity in most deep underground nuclear, astroparticle and double-beta decay physics experiments. Reliable neutron flux numbers are an important ingredient in the design of the shielding of new large-scale experiments as well as in the analysis of experimental data. Using a portable setup of {sup 3}He counters we measured the thermal neutron flux at the Kimballton Underground Research Facility, the Soudan Underground Laboratory, on the 4100 ft and the 4850 ft levels of the Sanford Underground Research Facility, at the Waste Isolation Pilot Plant and at the Gran Sasso National Laboratory. Absolute neutron fluxes at these laboratories are presented.

  16. 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

  17. 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.

  18. Spherical zonal components of cosmic ray between Forbush decreases

    International Nuclear Information System (INIS)

    Takahashi, Hachiro; Yahagi, Naohiro; Nagashima, Kazuo.

    1974-01-01

    Two examples are added to the previous report on the zonal harmonic components of cosmic ray in the space between planets by the three dimensional analysis of anisotropy of cosmic ray. Remarkable Forbush decreases occurred in region I during the period from March 20th to April 11th, 1966 and in region II during the period from August 29th to September 11th, 1966. The data used for analysis are the neutron components that have been informed from cosmic ray observation stations in the world. Power type and power exponential type differential rigidity spectra G(P) were used to find isotropic components. The change of the isotropic component a 0 0 was similar to the change of the neutron intensity in Deep River. The southnorth anisotropic phenomenon of cosmic ray intensity was recognized. The anisotropy in the opposite direction to the southnorth anisotropic phenomenon reported by Nagashima et al. was recognized markedly during the period from March 26th to 30th. These tendencies were checked by comparing with the data from the cosmic ray observation stations located near both poles of the earth. McMurdo and Mawson near the south pole, and Thule and Alert near the north pole were selected. The results of analysis were confirmed with these data. Further, the results of the previous report were checked by using the data from the stations near both poles, namely Thule, Resolute Bay, and Mawson. The good coincidence was confirmed on the anisotropic components. (Iwakiri, K.)

  19. Multi-parametric Effect of Solar Activity on Cosmic Rays V. K. Mishra ...

    Indian Academy of Sciences (India)

    Key words. Sun—solar parameters—cosmic ray modulation—running ... Neutron monitors are most sensitive to cosmic rays in the energy range. 0.5–20 GeV ... been considered as a primary indicator to define the level of solar activity, which.

  20. 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.

  1. 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

  2. Scoping studies - photon and low energy neutron interrogation

    Energy Technology Data Exchange (ETDEWEB)

    Becker, G.; Harker, Y.; Jones, J. [LMITCo, Idaho Falls, ID (United States); Harmon, F. [Idaho State Univ., Pocatello, ID (United States)

    1997-11-01

    High energy photon interrogation of waste containers, with the aim of producing photo nuclear reactions, in specific materials, holds the potential of good penetration and rapid analysis. Compact high energy ({le} 10 MeV) photon sources in the form of electron linacs producing bremstrahlung radiation are readily available. Work with the Varitron variable energy accelerator at ISU will be described. Advantages and limitations of the technique will be discussed. Using positive ion induced neutron producing reactions, it is possible to generate neutrons in a specific energy range. By this means, variable penetration and specific reactions can be excited in the assayed material. Examples using the {sup 3}H(p,n) and {sup 7}Li(p,n) reactions as neutron sources will be discussed. 4 refs., 7 figs.

  3. 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.

  4. 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.

  5. Reduction of cosmic-ray components by veto plastic scintillator

    International Nuclear Information System (INIS)

    Hamajima, Y.; Komura, K.

    2004-01-01

    The cosmic-ray component causes the background (BG) in the Ge detector set up on the above ground. The background reduction system was examined by using a plastic scintillator (PS) as a guard counter. It was possible to detect cosmic-ray enough even with a thin PS (0.5 mm in thickness). The resolving time of the timing signal between PS and Ge detector was needed for 10 microseconds. In anti-coincidence with the timing signals of PS, it was possible to reject 90% of the cosmic-ray component by setting up PS to cover the above hemisphere of the Ge detector. It is significant for the anti-coincidence system at above ground to set up effective shield by using ultra low BG Ge and shielding materials as much as possible. It was difficult to reject the secondary neutron component with this system. (author)

  6. Partial ring currents and cosmic ray magnetic cutoff rigidity variations

    International Nuclear Information System (INIS)

    Arens, M.

    1978-01-01

    A short introduction on cosmic ray modulation and a description of the magnetosphere, and of some physical processes occurring within its boundaries are presented. 20 geomagnetic storms are analysed together with the cosmic ray intensities during these storms as measured by Neutron Monitors. Using a semi-empirical method, the variations in the magnetic cutoff rigidity for the mountain stations Pic du Midi and Jungfraujoch are deduced. These stations are the most sensitive for measuring these variations. The analysis shows that all analyzed storms have an asymmetric development phase. Often the asymmetry even continues during part of the recovery phase. It is shown that variations in magnetic cutoff rigidity occur only during the asymmetric phase of the storm. The largest variations are found when the cosmic ray station is located in the late afternoon-midnight sector. (Auth.)

  7. A Kinematically Beamed, Low Energy Pulsed Neutron Source for Active Interrogation

    International Nuclear Information System (INIS)

    Dietrich, D.; Hagmann, C.; Kerr, P.; Nakae, L.; Rowland, M.; Snyderman, N.; Stoeffl, W.; Hamm, R.

    2004-01-01

    We are developing a new active interrogation system based on a kinematically focused low energy neutron beam. The key idea is that one of the defining characteristics of SNM (Special Nuclear Materials) is the ability for low energy or thermal neutrons to induce fission. Thus by using low energy neutrons for the interrogation source we can accomplish three goals, (1) Energy discrimination allows us to measure the prompt fast fission neutrons produced while the interrogation beam is on; (2) Neutrons with an energy of approximately 60 to 100 keV do not fission 238U and Thorium, but penetrate bulk material nearly as far as high energy neutrons do and (3) below about 100keV neutrons lose their energy by kinematical collisions rather than via the nuclear (n,2n) or (n,n') processes thus further simplifying the prompt neutron induced background. 60 keV neutrons create a low radiation dose and readily thermal capture in normal materials, thus providing a clean spectroscopic signature of the intervening materials. The kinematically beamed source also eliminates the need for heavy backward and sideway neutron shielding. We have designed and built a very compact pulsed neutron source, based on an RFQ proton accelerator and a lithium target. We are developing fast neutron detectors that are nearly insensitive to the ever-present thermal neutron and neutron capture induced gamma ray background. The detection of only a few high energy fission neutrons in time correlation with the linac pulse will be a clear indication of the presence of SNM

  8. Accuracy estimation for intermediate and low energy neutron transport calculation with Monte Carlo code MCNP

    International Nuclear Information System (INIS)

    Kotegawa, Hiroshi; Sasamoto, Nobuo; Tanaka, Shun-ichi

    1987-02-01

    Both ''measured radioactive inventory due to neutron activation in the shield concrete of JPDR'' and ''measured intermediate and low energy neutron spectra penetrating through a graphite sphere'' are analyzed using a continuous energy model Monte Carlo code MCNP so as to estimate calculational accuracy of the code for neutron transport in thermal and epithermal energy regions. Analyses reveal that MCNP calculates thermal neutron spectra fairly accurately, while it apparently over-estimates epithermal neutron spectra (of approximate 1/E distribution) as compared with the measurements. (author)

  9. Characterization of Monoenergetic Low Energy Neutron Fields with the {mu}TPC Detector

    Energy Technology Data Exchange (ETDEWEB)

    Golabek, C.; Lebreton, L.; Petit, M. [Laboratoire de Metrologie et de Dosimetrie des Neutrons, IRSN Cadarache, 13115 Saint-Paul-Lez-Durance (France); Billard, J.; Grignon, C.; Bosson, G.; Bourrion, O.; Guillaudin, O.; Mayet, F.; Richer, J.-P.; Santos, D. [Laboratoire de Physique Subatomique et de Cosmologie, Universite Joseph (France)

    2011-12-13

    The AMANDE facility produces monoenergetic neutron fields from 2 keV to 20 MeV for metrological purposes. To be considered as a reference facility, fluence and energy distributions of neutron fields have to be determined by primary measurement standards. For this purpose, a micro Time Projection Chamber is being developed to be dedicated to measure neutron fields with energy ranging from 2 keV up to 1 MeV. We present simulations showing that such a detector, which allows the measurement of the ionization energy and the 3D reconstruction of the recoil nucleus, provides the determination of neutron energy and fluence of such low energy neutron fields.

  10. 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

  11. 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)

  12. 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.

  13. On the origin of low energy tail for monoenergetic neutron sources

    International Nuclear Information System (INIS)

    Kornilov, N.V.; Kagalenko, A.B.

    1995-01-01

    The problems of data processing when measuring inelastic neutron scattering cross sections for separated nuclei levels are studied. The model describing the neutron energy distribution for monoenergetic neutron sources is developed. The factors which make the major contributions into spectrometer response function formation are discussed. It is shown that the model considered predicts well neutron energy distribution from metal Li-target. The model parameters should be estimated on the basis of the experimental data. The neutron scattering on target environment contributes much into the low energy region of the neutron spectrum. An additional neutron source is introduced into the model in order to describe the low energy peak asymmetry (the so-called low energy tail). The tail neutron contribution dependence on incident energy and angle turns out to be rather unexpected. The conclusion is made that it is difficult to explain the origin and the properties of the tail neutron source by slit proton scattering or some Li-nuclei distribution regularities. 3 refs., 6 figs

  14. Simulations and developments of the Low Energy Neutron detector Array LENA

    International Nuclear Information System (INIS)

    Langer, C.; Algora, A.; Couture, A.; Csatlós, M.; Gulyás, J.; Heil, M.; Krasznahorkay, A.; O'Donnell, J.M.; Plag, R.; Reifarth, R.; Stuhl, L.; Sonnabend, K.; Tornyi, T.; Tovesson, F.

    2011-01-01

    Prototypes of the Low Energy Neutron detector Array (LENA) have been tested and compared with detailed GEANT simulations. LENA will consist of plastic scintillation bars with the dimensions 1000×45×10 mm 3 . The tests have been performed with γ-ray sources and neutrons originating from the neutron-induced fission of 235 U. The simulations agreed very well with the measured response and were therefore used to simulate the response to mono-energetic neutrons with different detection thresholds. LENA will be used to detect low-energy neutrons from (p,n)-type reactions with low momentum transfer foreseen at the R 3 B and EXL setups at FAIR, Darmstadt.

  15. An absolute measurement of 252Cf prompt fission neutron spectrum at low energy range

    International Nuclear Information System (INIS)

    Lajtai, A.; Dyachenko, P.P.; Kutzaeva, L.S.; Kononov, V.N.; Androsenko, P.A.; Androsenko, A.A.

    1983-01-01

    Prompt neutron energy spectrum at low energies (25 keV 252 Cf spontaneous fission has been measured with a time-of-flight technique on a 30 cm flight-path. Ionization chamber and lithium-glass were used as fission fragment and neutron detectors, respectively. Lithium glasses of NE-912 (containing 6 Li) and of NE-913 (containing 7 Li) 45 mm in diameter and 9.5 mm in thickness have been employed alternatively, for the registration of fission neutrons and gammas. For the correct determination of the multiscattering effects - the main difficulty of the low energy neutron spectrum measurements - a special geometry for the neutron detector was used. Special attention was paid also to the determination of the absolute efficiency of the neutron detector. The real response function of the spectrometer was determined by a Monte-Carlo calculation. The scattering material content of the ionization chamber containing a 252 Cf source was minimized. As a result of this measurement a prompt fission neutron spectrum of Maxwell type with a T=1.42 MeV parameter was obtained at this low energy range. We did not find any neutron excess or irregularities over the Maxwellian. (author)

  16. Is there an Ay problem in low-energy neutron-proton scattering?

    International Nuclear Information System (INIS)

    Gross, Franz; Stadler, Alfred

    2008-01-01

    We calculate Ay in neutron-proton scattering for the interactions models WJC-1 and WJC-2 in the Covariant Spectator Theory. We find that the recent 12 MeV measurements performed at TUNL are in better agreement with our results than with the Nijmegen Phase Shift Analysis of 1993, and after reviewing the low energy data, conclude that there is no Ay problem in low-energy np scattering.

  17. 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?

  18. 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.

  19. Is there a link between cancer and cosmic rays?

    International Nuclear Information System (INIS)

    Astbury, A.

    2000-06-01

    Conventional wisdom on the carcinogenic effects of ionizing radiation predicts that only a very small percentage of human deaths from cancer can be attributed to cosmic rays. The intensity of the hadronic component of terrestrial cosmic rays, in particular neutrons, is well measured as a function of vertical threshold rigidity (M, in GeV/c). The crude death rates from malignant neoplasms for countries of the world and states of the US reveal a correlation with M. A close examination of eight US states with M ≤ 1.5 GeV/c over the period 1947-1997 shows systematic time variations with periodicities reminiscent of sunspot cycles (∼11 years). A very simple model linking the death rate from cancer to the count rate in a cosmic ray neutron monitor reproduces the gross features of the data. The evidence suggests that conventional wisdom could well be challenged. The situation may only be resolved by a series of detailed measurements of the genetic impact of hadronic cosmic rays on cells. (author)

  20. Spectrographical method for determining temperature variations of cosmic rays

    International Nuclear Information System (INIS)

    Dorman, L.I.; Krest'yannikov, Yu.Ya.; AN SSSR, Irkutsk. Sibirskij Inst. Zemnogo Magnetizma Ionosfery i Rasprostraneniya Radiovoln)

    1977-01-01

    A spectrographic method for determining [sigmaJsup(μ)/Jsup(μ)]sub(T) temperature variations in cosmic rays is proposed. The value of (sigmaJsup(μ)/Jsup(μ)]sub(T) is determined from three equations for neutron supermonitors and the equation for the muon component of cosmic rays. It is assumed that all the observation data include corrections for the barometric effect. No temperature effect is observed in the neutron component. To improve the reliability and accuracy of the results obtained the surface area of the existing devices and the number of spectrographic equations should be increased as compared with that of the unknown values. The value of [sigmaJsup(μ)/Jsup(μ)]sub(T) for time instants when the aerological probing was carried out, was determined from the data of observations of cosmic rays with the aid of a spectrographic complex of devices of Sib IZMIR. The r.m.s. dispersion of the difference is about 0.2%, which agrees with the expected dispersion. The agreement obtained can be regarded as an independent proof of the correctness of the theory of meteorological effects of cosmic rays. With the existing detection accuracy the spectrographic method can be used for determining the hourly values of temperature corrections for the muon component

  1. 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.

  2. Reconstructing the long-term cosmic ray intensity: linear relations do not work

    Directory of Open Access Journals (Sweden)

    K. Mursula

    2003-04-01

    Full Text Available It was recently suggested (Lockwood, 2001 that the cosmic ray intensity in the neutron monitor energy range is linearly related to the coronal source flux, and can be reconstructed for the last 130 years using the long-term coronal flux estimated earlier. Moreover, Lockwood (2001 reconstructed the coronal flux for the last 500 years using a similar linear relation between the flux and the concentration of cosmogenic 10 Be isotopes in polar ice. Here we show that the applied linear relations are oversimplified and lead to unphysical results on long time scales. In particular, the cosmic ray intensity reconstructed by Lockwood (2001 for the last 130 years has a steep trend which is considerably larger than the trend estimated from observations during the last 65 years. Accordingly, the reconstructed cosmic ray intensity reaches or even exceeds the local interstellar cosmic ray flux around 1900. We argue that these unphysical results obtained when using linear relations are due to the oversimplified approach which does not take into account the complex and essentially nonlinear nature of long-term cosmic ray modulation in the heliosphere. We also compare the long-term cosmic ray intensity based on a linear treatment with the reconstruction based on a recent physical model which predicts a considerably lower cosmic ray intensity around 1900.Key words. Interplanetary physics (cosmic rays; heliopause and solar wind termination – Geomagnetism and paleomagnetism (time variations, secular and long-term

  3. Low-energy neutron-induced single-event upsets in static random access memory

    International Nuclear Information System (INIS)

    Guo Xiaoqiang; Guo Hongxia; Wang Guizhen; Ling Dongsheng; Chen Wei; Bai Xiaoyan; Yang Shanchao; Liu Yan

    2009-01-01

    The visual analysis method of data process was provided for neutron-induced single-event upset(SEU) in static random access memory(SRAM). The SEU effects of six CMOS SRAMs with different feature size(from 0.13 μm to 1.50 μm) were studied. The SEU experiments were performed using the neutron radiation environment at Xi'an pulsed reactor. And the dependence of low-energy neutron-induced SEU cross section on SRAM's feature size was given. The results indicate that the decreased critical charge is the dominant factor for the increase of single event effect sensitivity of SRAM devices with decreased feature size. Small-sized SRAM devices are more sensitive than large-sized ones to single event effect induced by low-energy neutrons. (authors)

  4. 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...

  5. Neutron-triton scattering lengths for interactions reproducing low-energy trinucleon data

    International Nuclear Information System (INIS)

    Levashev, V.P.

    1981-01-01

    By solving the integral equations for four nucleons the neutron-triton scattering lengths and total cross section are calculated using different S-wave rank-one separable potentials. A number of linear correlations between the neutron-triton scattering lengths and triton binding energy are found. The scattering lengths consistent with low-energy trinucleon data. The results obtained are compared with available experimental data [ru

  6. Estimation of 129I by low energy spectrometry and neutron activation analysis

    International Nuclear Information System (INIS)

    Ravi, P.M.; Iyer, M.R.; Sahasrabudhe, S.G.; Somasundaram, S.; Subramanian, M.S.

    1986-01-01

    Methods have been developed for the estimation of 129 I by direct passive counting and by neutron activation analysis. The direct counting method using low energy photon spectrometry has been standardised for liquid samples. Interference from different induced radionuclides in the activation method was studied. Limits of detection of 129 I by direct counting method and neutron activation analysis work out to be 0.4 Bq and 1mBq respectively. (author). 6 refs

  7. 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.

  8. 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.

  9. 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.

  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. 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.)

  12. THE PRODUCTION OF LOW-ENERGY NEUTRONS IN SOLAR FLARES AND THE IMPORTANCE OF THEIR DETECTION IN THE INNER HELIOSPHERE

    International Nuclear Information System (INIS)

    Murphy, R. J.; Kozlovsky, B.; Share, G. H.

    2012-01-01

    Neutron detectors on spacecraft in the inner heliosphere can observe the low-energy ( ion –1 ) most important for producing low-energy neutrons from these reactions. We calculate escaping-neutron spectra and neutron-capture line yields from ions propagating in a magnetic loop with various kinetic-energy spectra. This study provides the basis for planning inner-heliospheric missions having a low-energy neutron detector. The MESSENGER spacecraft orbiting Mercury has such a detector. We conclude that a full understanding of ion acceleration, transport, and interaction at the Sun requires observation of both neutrons and gamma rays with detectors of comparable sensitivity. We find that the neutron-capture line fluence at 1 AU is comparable to the 1-10 MeV neutron fluence at 0.5 AU, and therefore as effective for revealing low-energy ion acceleration. However, as the distance from the Sun to the neutron detector decreases, the tremendous increase of the low-energy neutron flux allows exploration of ion acceleration in weak flares not previously observable and may reveal acceleration at other sites not previously detected where low-energy neutrons could be the only high-energy signature of ion acceleration. Also, a measurement of the low-energy neutron spectrum will provide important information about the accelerated-ion spectrum that is not available from the capture line fluence measurement alone.

  13. The electric dipole moment of the neutron in low energy supergravity

    International Nuclear Information System (INIS)

    Polchinski, J.; Wise, M.B.

    1983-01-01

    We compute the electric dipole moment of the neutron in models with low energy supergravity or softly broken supersymmetry. The electric dipole moment is typically of order 10sup(-(22-23))e cm times CP-violating phases. We discuss the origin of these phases. (orig.)

  14. Simulations of neutron transport at low energy: a comparison between GEANT and MCNP.

    Science.gov (United States)

    Colonna, N; Altieri, S

    2002-06-01

    The use of the simulation tool GEANT for neutron transport at energies below 20 MeV is discussed, in particular with regard to shielding and dose calculations. The reliability of the GEANT/MICAP package for neutron transport in a wide energy range has been verified by comparing the results of simulations performed with this package in a wide energy range with the prediction of MCNP-4B, a code commonly used for neutron transport at low energy. A reasonable agreement between the results of the two codes is found for the neutron flux through a slab of material (iron and ordinary concrete), as well as for the dose released in soft tissue by neutrons. These results justify the use of the GEANT/MICAP code for neutron transport in a wide range of applications, including health physics problems.

  15. 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

  16. 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)

  17. 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)

  18. Oncogenic transformation in C3H10T1/2 cells by low-energy neutrons.

    Science.gov (United States)

    Miller, R C; Marino, S A; Napoli, J; Shah, H; Hall, E J; Geard, C R; Brenner, D J

    2000-03-01

    Occupational exposure to neutrons typically includes significant doses of low-energy neutrons, with energies below 100 keV. In addition, the normal-tissue dose from boron neutron capture therapy will largely be from low-energy neutrons. Microdosimetric theory predicts decreasing biological effectiveness for neutrons with energies below about 350 keV compared with that for higher-energy neutrons; based on such considerations, and limited biological data, the current radiation weighting factor (quality factor) for neutrons with energies from 10 keV to 100 keV is less than that for higher-energy neutrons. By contrast, some reports have suggested that the biological effectiveness of low-energy neutrons is similar to that of fast neutrons. The purpose of the current work is to assess the relative biological effectiveness of low-energy neutrons for an endpoint of relevance to carcinogenesis: in vitro oncogenic transformation. Oncogenic transformation induction frequencies were determined for C3H10T1/2 cells exposed to two low-energy neutron beams, respectively, with dose-averaged energies of 40 and 70 keV, and the results were compared with those for higher-energy neutrons and X-rays. These results for oncogenic transformation provide evidence for a significant decrease in biological effectiveness for 40 keV neutrons compared with 350 keV neutrons. The 70 keV neutrons were intermediate in effectiveness between the 70 and 350 keV beams. A decrease in biological effectiveness for low-energy neutrons is in agreement with most (but not all) earlier biological studies, as well as microdosimetric considerations. The results for oncogenic transformation were consistent with the currently recommended decreased values for low-energy neutron radiation weighting factors compared with fast neutrons.

  19. Direct capture of low-energy neutrons by {sup 16}O

    Energy Technology Data Exchange (ETDEWEB)

    Kitazawa, Hideo [Tokyo Inst. of Tech., Nagatsuta, Yokohama (Japan). Interdisciplinary Graduate School of Science; Igashira, Masayuki

    1998-03-01

    A dispersive optical potential for the interaction between low-energy neutrons and {sup 16}O-nuclei is derived from a dispersion relation based on the Feshbach generalized optical model. This potential is applied to direct-capture model calculations in explaining the observed off-resonance capture transitions to the ground (5/2{sup +}) and 871 keV(1/2{sup +}) levels in {sup 17}O at neutron energies of 20-70 keV. The model calculations take account of the spatial nonlocality of the neutron-nucleus interaction potential. (author)

  20. 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

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. Three dimensional analysis of cosmic ray intensity variation

    International Nuclear Information System (INIS)

    Yasue, Shin-ichi; Mori, Satoru; Nagashima, Kazuo.

    1974-01-01

    Three dimensional analysis of cosmic ray anisotropy and its time variation was performed. This paper describes the analysis of the Forbush decrease in Jan. 1968 to investigate by comparing the direction of the magnetic field in interplanetary space and the direction of the reference axis for cosmic ray anisotropy. New anisotropy becomes dominant at the time of Forbush decrease because the anisotropy of cosmic ray in calm state is wiped out. Such anisotropy produces intensity variation in neutron monitors on the ground. The characteristic parameters of three dimensional anisotropy can be determined from theoretical value and observed intensity. Analyzed data were taken for 6 days from Jan. 25 to Jan. 30, 1968, at Deep River. The decrease of intensity at Deep River was seen for several hours from 11 o'clock (UT), Jan. 26, just before The Forbush decrease. This may be due to the loss cone. The Forbush decrease began at 19 o'clock, Jan. 26, and the main phase continued to 5 o'clock in the next morning. The spectrum of variation was Psup(-0.5). The time variations of the magnetic field in interplanetary space and the reference axis of cosmic ray anisotropy are shown for 15 hours. The average directions of both are almost in coincidence. The spatial distribution of cosmic ray near the earth may be expressed by the superposition of axial symmetrical distribution along a reference axis and its push-out to the direction of 12 o'clock. It is considered that the direction of magnetic force line and the velocity of solar wind correspond to the direction of the reference axis and the magnitude of anisotropy in the direction of 12 o'clock, respectively. (Kato, T.)

  7. 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

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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)

  14. 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

  15. Low energy nuclear spin excitations in Ho metal investigated by high resolution neutron spectroscopy.

    Science.gov (United States)

    Chatterji, Tapan; Jalarvo, Niina

    2013-04-17

    We have investigated the low energy excitations in metallic Ho by high resolution neutron spectroscopy. We found at T = 3 K clear inelastic peaks in the energy loss and energy gain sides, along with the central elastic peak. The energy of this low energy excitation, which is 26.59 ± 0.02 μeV at T = 3 K, decreased continuously and became zero at TN ≈ 130 K. By fitting the data in the temperature range 100-127.5 K with a power law we obtained the power-law exponent β = 0.37 ± 0.02, which agrees with the expected value β = 0.367 for a three-dimensional Heisenberg model. Thus the energy of the low energy excitations can be associated with the order parameter.

  16. A time series approach to the correction for atmosphere effects and the significance of a semi-diurnal variation in corrected intensities of secondary cosmic ray neutrons and mesons (NM64 and MT64)

    International Nuclear Information System (INIS)

    Huijsmans, D.P.

    1982-01-01

    The aim of this research was to distinguish as accurately as possible between two mechanisms behind a half-daily variation in detected numbers of neutrons and mesons in the secondary cosmic ray particles at sea level. These two mechanisms are due to air pressure variations at sea level and affect the number of primary particles with a certain arrival direction. The distribution among arrival directions in the ecliptic plane varies if a gradient exists in the guiding centre density of primaries in directions perpendicular to the neutral sheet. Chapter 2 is devoted to the calculation of a physically and statistically justifiable determination of the barometric coefficient for neutron measurements and air pressures. Chapter 3 deals with the estimation of atmospheric correction coefficients for the elimination of the influence of changing atmospheric conditions on the number of detected mesons. For mesons the variation of total mass, and also the variations in mass-distribution along the trajectory of the mesons are important. After correction for atmospheric variations using the resulting atmospheric correction coefficients from chapter 2 and 3, the influence of the structure of the interplanetary magnetic field near the earth is examined in chapter 4. 0inally, in chapter 5, a power spectral analysis of variations in corrected intensities of neutrons and mesons is carried out. Such an analysis distinguishes the variance of a time series into contributions within small frequency intervals. From the power spectra of variations on a yearly basis, a statistically fundamented judgement can be given as to the significance of the semi-diurnal variation during the different phases of the solar magnetic activity cycle. (Auth.)

  17. Neutron-scattering study of low-energy excitations in triphenyl phosphite

    CERN Document Server

    Mayer, J; Massalska-Arodz, M; Janik, J A; Natkaniec, I; Steinsvoll, O

    2002-01-01

    The low-energy excitations in crystalline and glassy triphenyl phosphite were studied by inelastic incoherent neutron scattering with two different instruments. The results - the incoherent dynamic structure factor S(2 theta,omega) and the density of states G(omega) - were obtained using direct and inverted geometry time-of-flight spectrometers, respectively. The probable origin of the excess density of states in the glass (boson peak) is discussed. (orig.)

  18. Neutron-scattering study of low-energy excitations in triphenyl phosphite

    International Nuclear Information System (INIS)

    Mayer, J.; Krawczyk, J.; Massalska-Arodz, M.; Janik, J.A.; Natkaniec, I.; Steinsvoll, O.

    2002-01-01

    The low-energy excitations in crystalline and glassy triphenyl phosphite were studied by inelastic incoherent neutron scattering with two different instruments. The results - the incoherent dynamic structure factor S(2θ,ω) and the density of states G(ω) - were obtained using direct and inverted geometry time-of-flight spectrometers, respectively. The probable origin of the excess density of states in the glass (boson peak) is discussed. (orig.)

  19. The neutron electric dipole moment in left-right symmetric low energy supergravity

    International Nuclear Information System (INIS)

    Ahn, Y.J.

    1984-01-01

    We compute the neutron electric dipole moment in low energy supergravity based on the gauge group SU(2)sub(L) x SU(2)sub(R) x U(1)sub(B-L). We find the electric dipole moment dsub(n) -25 e cm x (CP violating phase) provided the left-right symmetry breaking scale > or approx. 10 3 GeV. (orig.)

  20. 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.)

  1. 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

  2. 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)

  3. Cosmic Ray Daily Variation And SOLAR Activity On Anomalous Days

    International Nuclear Information System (INIS)

    Mishra, Rajesh Kumar; Mishra, Rekha Agarwal

    2008-01-01

    A study is carried out on the long-term changes in the diurnal anisotropy of cosmic rays using the ground based Deep River neutron monitor data during significantly low amplitude anisotropic wave train events in cosmic ray intensity for the period 1981-94. It has been observed that the phase of the diurnal anisotropy for majority of the low amplitude anisotropic wave train events significantly shifts towards earlier hours as compared to the co-rotational direction. The long-term behaviour of the amplitude of the diurnal anisotropy can be explained in terms of the occurrence of low amplitude anisotropic wave train events. The occurrence of these events is dominant during solar activity minimum years. The amplitude of the diurnal anisotropy is well correlated with the solar cycle but the direction of the anisotropy is not correlated with the solar cycle and shows a systematic shift to earlier hours. (authors)

  4. Variations of interplanetary parameters and cosmic-ray intensities

    International Nuclear Information System (INIS)

    Geranios, A.

    1980-01-01

    Observations of cosmic ray intensity depressions by earth bound neutron monitors and measurements of interplanetary parameter's variations aboard geocentric satellites in the period January 1972-July 1974 are analysed and grouped according to their correlation among them. From this analysis of about 30 cases it came out that the majority of the depressions correlates with the average propagation speed of interplanetary shocks as well as with the amplitude of the interplanetary magnetic field after the eruption of a solar flare. About one fourth of the events correlates with corotating fast solar wind streams. As the recovery time of the shock-related depressions depends strongly on the heliographic longitude of the causitive solar flare, it seems that the cosmic ray modulation region has a corotative-like feature. (Auth.)

  5. Some principal problems in physics and low-energy neutron physics

    International Nuclear Information System (INIS)

    Aleksandrov, Yu.A.

    2004-01-01

    The questions connected with internal particle (e.g. neutron) structure obtained at low-energy neutron physics are discussed. The first question deals with the charge neutron radius E 2 > 1/2 connected with the value of neutron-electron scattering length a ne determined at low neutron energies. At present, the obtained accuracy allows us to speak not only about the value of E 2 > but also on the segmentation of E 2 > into Dirac and Foldy addenda. The sign of the Dirac addendum is connected directly with the fundamental Yukawa theory explaining the origin of nuclear forces. One of the popular experimental values of the Dirac addendum (from a ne =(-1.32±0.03)·10 -16 cm) contradicts the Yukawa theory. The second question also concerns the subject of the structure of the neutron, namely its deformation. The notion of deformation (polarizability) of the nucleon in electromagnetic field was introduced in the mid-1950s. The reasons are given in favor of the opinion that the neutron polarizability was observed for the first time in neutron experiments as far back as 1957, i.e. earlier than proton polarizability was detected (1960). Finally, the third question deals with the search for a magnetic charge of the neutron. A beautiful experiment (Finkelstein, Shull, Zeilinger, 1986) testifying with high accuracy the absence of a magnetic charge of the neutron is discussed. This diffraction experiment was based on the concept of anomalously small effective mass of the neutron providing greatly enhanced sensitivity. The existence of an isolated magnetic charge in the nature would explain the quantization of electric and magnetic charges (Dirac, 1931)

  6. The Production of Low-energy Neutrons in Solar Flares and the Importance of Their Detection in the Inner Heliosphere

    Science.gov (United States)

    Murphy, R. J.; Kozlovsky, B.; Share, G. H.

    2012-09-01

    Neutron detectors on spacecraft in the inner heliosphere can observe the low-energy (computer code incorporating updated neutron-production cross sections for the proton and α-particle reactions with heavier elements at all ion energies, especially at low energies (E ion Mercury has such a detector. We conclude that a full understanding of ion acceleration, transport, and interaction at the Sun requires observation of both neutrons and gamma rays with detectors of comparable sensitivity. We find that the neutron-capture line fluence at 1 AU is comparable to the 1-10 MeV neutron fluence at 0.5 AU, and therefore as effective for revealing low-energy ion acceleration. However, as the distance from the Sun to the neutron detector decreases, the tremendous increase of the low-energy neutron flux allows exploration of ion acceleration in weak flares not previously observable and may reveal acceleration at other sites not previously detected where low-energy neutrons could be the only high-energy signature of ion acceleration. Also, a measurement of the low-energy neutron spectrum will provide important information about the accelerated-ion spectrum that is not available from the capture line fluence measurement alone.

  7. 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.

  8. 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.

  9. 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.

  10. Source composition of cosmic rays at high energy

    International Nuclear Information System (INIS)

    Juliusson, E.; Cesarsky, C.J.; Meneguzzi, M.; Casse, M.

    1975-01-01

    The source composition of the cosmic ray is usually calculated at an energy of a few GeV per nucleon. Recent measurements have however indicated that the source composition may be energy dependent. In order to give a quantitative answer to this question the source composition at 50GeV/nucleon has been calculated using an exponential distribution of path lengths and in the slab approximation. The results obtained at high energy agree very well with the source composition obtained at lower energies, except the abundance of carbon which is significantly lower than the generally accepted value of low energies [fr

  11. Cosmic ray anisotropy along with interplanetary transients

    Science.gov (United States)

    Mishra, Rajesh Kumar

    The present work deals with the study of first three harmonics of low amplitude anisotropic wave trains of cosmic ray intensity over the period 1991-1994 for Deep River neutron monitoring station. It is observed that the diurnal time of maximum remains in the corotational direction; whereas, the time of maximum for both diurnal and semi-diurnal anisotropy has significantly shifted towards later hours as compared to the quiet day annual average for majority of the LAE events. It is noticed that these events are not caused either by the high-speed solar wind streams or by the sources on the Sun responsible for producing these streams; such as, polar coronal holes. The direction of the tri-diurnal anisotropy shows a good negative correlation with Bz component of interplanetary magnetic field. The occurrence of low amplitude events is dominant for positive polarity of Bz. The Disturbance Storm Time index i.e. Dst remains consistently negative only throughout the entire low amplitude wave train event.

  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. 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

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. Investigating the response of Micromegas detector to low-energy neutrons using Monte Carlo simulation

    Science.gov (United States)

    Khezripour, S.; Negarestani, A.; Rezaie, M. R.

    2017-08-01

    Micromegas detector has recently been used for high-energy neutron (HEN) detection, but the aim of this research is to investigate the response of the Micromegas detector to low-energy neutron (LEN). For this purpose, a Micromegas detector (with air, P10, BF3, 3He and Ar/BF3 mixture) was optimized for the detection of 60 keV neutrons using the MCNP (Monte Carlo N Particle) code. The simulation results show that the optimum thickness of the cathode is 1 mm and the optimum of microgrid location is 100 μm above the anode. The output current of this detector for Ar (3%) + BF3 (97%) mixture is greater than the other ones. This mixture is considered as the appropriate gas for the Micromegas neutron detector providing the output current for 60 keV neutrons at the level of 97.8 nA per neutron. Consecuently, this detector can be introduced as LEN detector.

  19. PANDORA, a large volume low-energy neutron detector with real-time neutron-gamma discrimination

    Science.gov (United States)

    Stuhl, L.; Sasano, M.; Yako, K.; Yasuda, J.; Baba, H.; Ota, S.; Uesaka, T.

    2017-09-01

    The PANDORA (Particle Analyzer Neutron Detector Of Real-time Acquisition) system, which was developed for use in inverse kinematics experiments with unstable isotope beams, is a neutron detector based on a plastic scintillator coupled to a digital readout. PANDORA can be used for any reaction study involving the emission of low energy neutrons (100 keV-10 MeV) where background suppression and an increased signal-to-noise ratio are crucial. The digital readout system provides an opportunity for pulse shape discrimination (PSD) of the detected particles as well as intelligent triggering based on PSD. The figure of merit results of PANDORA are compared to the data in literature. Using PANDORA, 91 ± 1% of all detected neutrons can be separated, while 91 ± 1% of the detected gamma rays can be excluded, reducing the gamma ray background by one order of magnitude.

  20. 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....

  1. 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

  2. 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'.

  3. 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...

  4. 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.

  5. Low-energy beam transport studies supporting the spallation neutron source 1-MW beam operation.

    Science.gov (United States)

    Han, B X; Kalvas, T; Tarvainen, O; Welton, R F; Murray, S N; Pennisi, T R; Santana, M; Stockli, M P

    2012-02-01

    The H(-) injector consisting of a cesium enhanced RF-driven ion source and a 2-lens electrostatic low-energy beam transport (LEBT) system supports the spallation neutron source 1 MW beam operation with ∼38 mA beam current in the linac at 60 Hz with a pulse length of up to ∼1.0 ms. In this work, two important issues associated with the low-energy beam transport are discussed: (1) inconsistent dependence of the post-radio frequency quadrupole accelerator beam current on the ion source tilt angle and (2) high power beam losses on the LEBT electrodes under some off-nominal conditions compromising their reliability.

  6. Do coronal holes influence cosmic ray daily harmonics

    International Nuclear Information System (INIS)

    Ahluwalia, H.S.

    1977-01-01

    Coronal holes are identified by their low emissivity in either EUV (Munro and Withrobe, 1973) or in X-rays (Krieger et al, 1973). They are seats of unidirectional magnetic fields. Also, high speed solar wind streams originate in them. Also, high speed solar wind streams originate in then (Krieger et al, 1973; Neupert and Pizzo, 1974; Nolte et al, 1976). Coronal holes often extend over a wide range of heliolatitudes (Timothy et al, 1975). Elsewhere in the Proceedings we have presented results on the long term changes observed in the amplitudes and the times of maximum of the diurnal, the semidiurnal and the tridiurnal variations of cosmic rays, at low (neutrons) and at high (underground muons) primary rigidities (Ahluwalia, 1977). We have shown that a dramatic shift to early hours is noticeable in the times of maxima of the harmonics during 1971-72 period. In this paper we examine the nature of the contributions of off-ecliptic cosmic rays of high enough rigidity, streaming under the influence of large scale ordered interplanetary magnetic field set up by the coronal holes, to the cosmic ray daily harmonics. Some models are presented and discussed in a preliminary fashion. (author)

  7. Use of borated polyethylene to improve low energy response of a prompt gamma based neutron dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Priyada, P.; Ashwini, U.; Sarkar, P.K., E-mail: pradip.sarkar@manipal.edu

    2016-05-21

    The feasibility of using a combined sample of borated polyethylene and normal polyethylene to estimate neutron ambient dose equivalent from measured prompt gamma emissions is investigated theoretically to demonstrate improvements in low energy neutron dose response compared to only polyethylene. Monte Carlo simulations have been carried out using the FLUKA code to calculate the response of boron, hydrogen and carbon prompt gamma emissions to mono energetic neutrons. The weighted least square method is employed to arrive at the best linear combination of these responses that approximates the ICRP fluence to dose conversion coefficients well in the energy range of 10{sup −8} MeV to 14 MeV. The configuration of the combined system is optimized through FLUKA simulations. The proposed method is validated theoretically with five different workplace neutron spectra with satisfactory outcome. - Highlights: • An improved method is proposed for estimating H⁎(10) using prompt gamma emissions. • A combination of BHDPE and HDPE cylinders is used as a sample. • Linear combination of prompt gamma intensities approximates ICRP-DCC closely. • Feasibility of the method was tested theoretically using workplace neutron spectra.

  8. 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

  9. Nuclear vorticity and the low-energy nuclear response. Towards the neutron drip line

    International Nuclear Information System (INIS)

    Papakonstantinou, P.; Athens Univ.; Wambach, J.; Ponomarev, V.Y.; Mavrommatis, E.

    2004-01-01

    The transition density and current provide valuable insight into the nature of nuclear vibrations. Nuclear vorticity is a quantity related to the transverse transition current. In this work, we study the evolution of the strength distribution, related to density fluctuations, and the vorticity strength distribution, as the neutron drip line is approached. Our results on the isoscalar, natural-parity multipole response of Ni isotopes, obtained by using a self-consistent Skyrme-Hartree-Fock+continuum RPA model, indicate that, close to the drip line, the low-energy response is dominated by L > 1 vortical transitions. (orig.)

  10. Neural network and wavelets in prediction of cosmic ray variability: The North Africa as study case

    Science.gov (United States)

    Zarrouk, Neïla; Bennaceur, Raouf

    2010-04-01

    Since the Earth is permanently bombarded with energetic cosmic rays particles, cosmic ray flux has been monitored by ground based neutron monitors for decades. In this work an attempt is made to investigate the decomposition and reconstructions provided by Morlet wavelet technique, using data series of cosmic rays variabilities, then to constitute from this wavelet analysis an input data base for the neural network system with which we can then predict decomposition coefficients and all related parameters for other points. Thus the latter are used for the recomposition step in which the plots and curves describing the relative cosmic rays intensities are obtained in any points on the earth in which we do not have any information about cosmic rays intensities. Although neural network associated with wavelets are not frequently used for cosmic rays time series, they seems very suitable and are a good choice to obtain these results. In fact we have succeeded to derive a very useful tool to obtain the decomposition coefficients, the main periods for each point on the Earth and on another hand we have now a kind of virtual NM for these locations like North Africa countries, Maroc, Algeria, Tunisia, Libya and Cairo. We have found the aspect of very known 11-years cycle: T1, we have also revealed the variation type of T2 and especially T3 cycles which seem to be induced by particular Earth's phenomena.

  11. Are gamma-ray bursts the sources of ultra-high energy cosmic rays?

    International Nuclear Information System (INIS)

    Baerwald, Philipp

    2014-07-01

    We reconsider the possibility that gamma-ray bursts (GRBs) are the sources of the ultra-high energy cosmic rays (UHECRs) within the internal shock model, assuming a pure proton composition of the UHECRs. For the first time, we combine the information from gamma-rays, cosmic rays, prompt neutrinos, and cosmogenic neutrinos quantitatively in a joint cosmic ray production and propagation model, and we show that the information on the cosmic energy budget can be obtained as a consequence. In addition to the neutron model, we consider alternative scenarios for the cosmic ray escape from the GRBs, i.e., that cosmic rays can leak from the sources. We find that the dip model, which describes the ankle in UHECR observations by the pair production dip, is strongly disfavored in combination with the internal shock model because (a) unrealistically high baryonic loadings (energy in protons versus energy in electrons/gamma-rays) are needed for the individual GRBs and (b) the prompt neutrino flux easily overshoots the corresponding neutrino bound. On the other hand, GRBs may account for the UHECRs in the ankle transition model if cosmic rays leak out from the source at the highest energies. In that case, we demonstrate that future neutrino observations can efficiently test most of the parameter space - unless the baryonic loading is much larger than previously anticipated.

  12. Low energy neutron scattering for energy dependent cross sections. General considerations

    Energy Technology Data Exchange (ETDEWEB)

    Rothenstein, W; Dagan, R [Technion-Israel Inst. of Tech., Haifa (Israel). Dept. of Mechanical Engineering

    1996-12-01

    We consider in this paper some aspects related to neutron scattering at low energies by nuclei which are subject to thermal agitation. The scattering is determined by a temperature dependent joint scattering kernel, or the corresponding joint probability density, which is a function of two variables, the neutron energy after scattering, and the cosine of the angle of scattering, for a specified energy and direction of motion of the neutron, before the interaction takes place. This joint probability density is easy to calculate, when the nucleus which causes the scattering of the neutron is at rest. It can be expressed by a delta function, since there is a one to one correspondence between the neutron energy change, and the cosine of the scattering angle. If the thermal motion of the target nucleus is taken into account, the calculation is rather more complicated. The delta function relation between the cosine of the angle of scattering and the neutron energy change is now averaged over the spectrum of velocities of the target nucleus, and becomes a joint kernel depending on both these variables. This function has a simple form, if the target nucleus behaves as an ideal gas, which has a scattering cross section independent of energy. An energy dependent scattering cross section complicates the treatment further. An analytic expression is no longer obtained for the ideal gas temperature dependent joint scattering kernel as a function of the neutron energy after the interaction and the cosine of the scattering angle. Instead the kernel is expressed by an inverse Fourier Transform of a complex integrand, which is averaged over the velocity spectrum of the target nucleus. (Abstract Truncated)

  13. 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.

  14. Intensity variation of cosmic rays near the heliospheric current sheet

    International Nuclear Information System (INIS)

    Badruddin, K.S.; Yadav, R.S.; Yadav, N.R.

    1985-01-01

    Cosmic ray intensity variations near the heliospheric current sheet-both above and below it-have been studied during 1964-76. Superposed epoch analysis of the cosmic ray neutron monitor data with respect to sector boundaries (i.e., heliospheric current sheet crossings) has been performed. In this analysis data from neutron monitors well distributed in latitude over the Earth's surface is used. First, this study has been made during the two solar activity minimum periods 1964-65 and 1975-76, using the data from Thule (cut-off rigidity O GV), Deep River (cut-off rigidity 1.02 GV), Rome (cut-off rigidity 6.32 GV) and Huancayo (cut-off rigidity 13.45 GV) neutron monitors. The data is analyzed from Deep River, Rome and Huancayo neutron monitors, for which data is available for the full period (1964-76), by dividing the periods according to the changes in solar activity, interplanetary magnetic field polarity and coronal holes. All these studies have shown a negative gradient with respect to heliomagnetic latitude (current sheet). These results have been discussed in the light of theoretical and observational evidences. Suggestions have been given to overcome the discrepancy between the observational and theoretical results. Further, possible explanations for these observational results have been suggested. (author)

  15. Neutron and X-ray emission studies in a low energy plasma focus

    Energy Technology Data Exchange (ETDEWEB)

    Zakaullah, M. [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Physics; Murtaza, G. [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Physics; Qamar, S. [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Physics; Ahmad, I. [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Physics; Beg, M.M. [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Physics

    1996-03-01

    In a low energy Mather-type plasma focus energized by a single 32 {mu}F capacitor, the X-ray and neutron emission is investigated using time-integrated and time-resolved detectors. The X-ray emission profile has a width (FWHM) of 40-50 ns. The neutron emission profile is broader compared to the X-ray emission profile and also delayed by 30-40 ns. To identify different regimes of X-ray emission, an X-ray pin-hole camera along with different absorption filters is employed. While the X-ray emission is high within a narrow pressure range of 2.0-2.5 mbar, the neutron emission is intense for a wider range of 1.0-4.5 mbar. The intense X-ray emission seems to originate from the axially moving shock wave. These results also indicate rather different production mechanisms for X-ray and neutron emission. Also on comparing the X-ray images with Al(2 {mu}m), Al(5 {mu}m), Al(9 {mu}m) filters, we find that the bulk of X-rays from the focus filament have energies less than 2 keV. (orig.).

  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. 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...

  18. Dosimetry of environmental radiations (cosmic ray)

    International Nuclear Information System (INIS)

    Yamasaki, Keizo

    1978-01-01

    Cosmic ray is dominant as environmental radiation, though the experimental determination made on cosmic ray doses is few in Japan. The free air ionization intensity at sea level due to cosmic ray has been estimated in the Bay of Wakasa, Japan, at middle geomagnetic latitude (25 deg. N), in October 1977. The ionization chambers used were two air and one argon types. Where the responses to cosmic and terrestrial gamma rays were equal, the ionization intensity due to cosmic ray was obtained by subtracting the ionization intensity due to terrestrial gamma ray from the total ionization intensity. As the terrestrial gamma ray, (1) U-238 series, Th-232 series, and K-40 in seawater, (2) K-40 in the material of a wooden ship, and (3) Rn-222 and its daughter products in the atmosphere were considered. The result of free air ionization due to cosmic ray with the argon chamber was slightly smaller than those with the other two air chambers; however, both were in good agreement within standard errors. (JPN.)

  19. 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.

  20. 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.

  1. DOSIMETRIC response of a REM-500 in low energy neutron fields typical of nuclear power plants.

    Science.gov (United States)

    Aslam; Matysiak, W; Atanackovic, J; Waker, A J

    2012-06-01

    This study investigates the response of a REM-500 to assess neutron quality factor and dose equivalent in low energy neutron fields, which are commonly encountered in the workplace environment of nuclear power stations. The McMaster University 3 MV Van de Graaff accelerator facility was used to measure the response of the instrument in monoenergetic neutron fields in the energy range 51 to 727 keV by bombarding a thin LiF target with 1.93-2.50 MeV protons. The energy distribution of the neutron fields produced in the facility was measured by a (3)He filled gas ionization chamber. The MCA mode of the REM-500 instrument was used to collect lineal energy distributions at varying neutron energies and to calculate the frequency and dose-mean lineal energies. The effective quality factor, Q-, was also calculated using the values of Q(y)listed in the REM-500 operation manual and compared with those of ICRP 60. The authors observed a continuously increasing trend in y - F, y-D, and Q-with an increase in neutron energy. It is interesting to note that standard tissue equivalent proportional counters (TEPCs) filled with tissue equivalent(TE) gas give rise to a similar trend for these microdosimetric quantities of interest in the same energy range; however, the averages calculated in this study are larger by about 15%compared to a TEPC filled with propane-based TE gas probably because of the larger stopping power of protons in propane compared to TE gas. These somewhat larger event sizes did not result in any significant increase in the Q-compared to those obtained from a TEPC filled with TE gas and were found to be in good agreement with other measurements reported earlier at corresponding neutron energies. The instrument quality factor response, R(Q), defined as the ratio of measured quality factor to the calculated quality factor in an ICRU tissue sphere,was found to vary with neutron energy. The instrument response,R(Q), was ~0.6 at 727 keV, which deteriorates further to

  2. 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.

  3. Low-Energy Neutron Production in Solar Flares and the Importance of their Detection in the Inner Heliosphere

    Science.gov (United States)

    Murphy, Ronald; Kozlovsky, B.; Share, G.

    2012-05-01

    Neutron detectors on spacecraft in the inner-heliosphere can observe the low-energy (computer code incorporating up-dated neutron-production cross sections of the accelerated proton and alpha-particle reactions with heavier elements at low ion energies (Mercury. We conclude that a full understanding of ion acceleration, transport, and interaction at the Sun requires observations of both neutrons and gamma rays. We find that a measurement of the 2.223 MeV neutron-capture line, even with a modest instrument at 1 AU, is as sensitive to the presence of low-energy interacting ions at the Sun as a 1-10 MeV neutron detector at 0.5 AU. However, as the distance from the Sun to the neutron detector decreases, the tremendous increase of the low-energy neutron flux will allow exploration of ion acceleration in weak flares not previously observable and may reveal ion acceleration at other sites not previously detected where low-energy neutron production could be the only high-energy signature of ion acceleration.

  4. Measurement of the Cosmic Ray primary spectrum with ARGO-YBJ experiment

    International Nuclear Information System (INIS)

    Panico, B; Iuppa, R; Di Sciascio, G

    2013-01-01

    The study of cosmic ray physic of 10 12 – 10 15 primary cosmic energy is one of the main goals of ARGO-YBJ experiment. The detector, located at the Yangbajing Cosmic Ray Laboratory (Tibet, 4300 m a.s.l., 606 g/cm 2 ), is an EAS array consisting of a continuous carpet of RPCs. The low energy threshold of the detector allows to study an energy region characterized by the transition from the direct to the indirect measurements. In this talk we will report on the measurement of the cosmic ray energy spectrum at different zenith angles. The phenomenology of horizontal air shower (θ > 70°) will be described and discussed.

  5. Theory of geomagnetic effects of cosmic rays: its past and presence

    Energy Technology Data Exchange (ETDEWEB)

    Gall, R [Universidad Nacional Autonoma de Mexico, Mexico City. Inst. de Geofisica

    1981-03-01

    The interest expressed by Lemaitre and Vallarta in the nature of universal corpuscular radiation, remnant of the exploded primogenitive atom, culminated in 1932, in the development of their theory of the geomagnetic effects of cosmic rays, a tool since its publication, basic to cosmic radiation research and to the advancement of cosmic ray astronomy. Between 1940 and 1960 challenging experimental data from proliferating cosmic radiation stations and of direct detection techniques provided geomagnetic field models for greater theoretical precision. The discoveries since the advent of the space age of the Earth's cavity and geomagnetic tail, and of the nonrelativistic solar cosmic rays have resulted in a new branch of the theory dealing with magnetosphere effects in the propagation of low energy cosmic radiations. The theory's importance and application to cosmic bodies other than the Earth is discussed.

  6. 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.

  7. 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

  8. Cosmic ray modulation and merged interaction regions

    International Nuclear Information System (INIS)

    Burlaga, L.F.; Goldstein, M.L.; Mcdonald, F.B.

    1985-01-01

    Beyond several AU, interactions among shocks and streams give rise to merged interaction regions in which the magnetic field is turbulent. The integral intensity of . 75 MeV/Nuc cosmic rays at Voyager is generally observed to decrease when a merged interaction region moves past the spacecraft and to increase during the passage of a rarefaction region. When the separation between interaction regions is relatively large, the cosmic ray intensity tends to increase on a scale of a few months. This was the case at Voyager 1 from July 1, 1983 to May 1, 1984, when the spacecraft moved from 16.7 to 19.6 AU. Changes in cosmic ray intensity were related to the magnetic field strength in a simple way. It is estimated that the diffusion coefficient in merged interaction regions at this distance is similar to 0.6 x 10 to the 22nd power sq cm/s

  9. Anomalous isotopic composition of cosmic rays

    International Nuclear Information System (INIS)

    Woosley, S.E.; Weaver, T.A.

    1980-01-01

    Recent measurements of nonsolar isotopic patterns for the elements neon and (perhaps) magnesium in cosmic rays are interpreted within current models of stellar nucleosynthesis. One possible explanation is that the stars currently responsible for cosmic-ray synthesis in the Galaxy are typically super-metal-rich by a factor of two to three. Other possibilities include the selective acceleration of certain zones or masses of supernovas or the enhancement of 22 Ne in the interstellar medium by mass loss from red giant stars and planetary nebulas. Measurements of critical isotopic ratios are suggested to aid in distinguishing among the various possibilities. Some of these explanations place significant constraints on the fraction of cosmic ray nuclei that must be fresh supernova debris and the masses of the supernovas involved. 1 figure, 3 tables

  10. 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

  11. A formalism for cosmic ray propagation studies

    International Nuclear Information System (INIS)

    Golden, R.L.; Badhwar, G.D.; Stephens, S.A.

    1975-01-01

    The continuity equation for cosmic ray propagation is used to derive a set of linear equations interrelating the fluxes of multiply charged nuclei as observed at any particular part of the galaxy. The derivation leads to model indepent definitions for cosmic ray storage time, mean density of target nuclei and effective mass traversed. The set of equations form a common framework for comparisons of theories and observations. As an illustration, it is shown that there exists a large class of propagation models which give the same result as the exponential path length model. (orig./BJ) [de

  12. Status of the UMC cosmic ray experiment

    International Nuclear Information System (INIS)

    Nitz, D.

    1989-01-01

    The UMC Ultra High Energy cosmic ray experiment is a collaboration among the University of Utah, the University of Michigan, and the University of Chicago. It is located at the site of the Fly's Eye II experiment at Dugway, Utah, at latitude 40.2 0 and an atmospheric depth of 850 gm/cm 2 . Extensive air shower (EAS) surface arrays, a large area muon counter array, tracking Cerenkov telescopes, and the Fly's Eye detector constitute the elements of a versatile cosmic ray observatory for > or approx. 10 14 eV extensive air showers. (orig.)

  13. Cosmic Rays: studies and measurements before 1912

    Energy Technology Data Exchange (ETDEWEB)

    De Angelis, Alessandro [INFN and Università di Udine, Via delle Scienze 206, I-33100 Udine (Italy); LIP/IST Lisboa (Portugal)

    2013-06-15

    The discovery of cosmic rays, a milestone in science, was based on the work by scientists in Europe and the New World and took place during a period characterised by nationalism and lack of communication. Many scientists that took part in this research a century ago were intrigued by the penetrating radiation and tried to understand the origin of it. Several important contributions to the discovery of the origin of cosmic rays have been forgotten; historical, political and personal facts might have contributed to their substantial disappearance from the history of science.

  14. Isotopic composition of cosmic ray nuclei

    International Nuclear Information System (INIS)

    Enge, W.

    1976-01-01

    A review will be given on the role of cosmic ray isotopes as tracers of the astrophysical nucleo-synthesis. The products of every nuclear burning chain are first of all isotopes and not elements. Thus, it is the study of the isotopes rather than that of the elements that responds to the questions on these nucleo-synthetic reactions. The problems concerning the solar system isotopic abundances and the cosmic ray isotopic abundances as well as a comparison between both will be presented. Furthermore the present stage of the experimental techniques and the latest results will be discussed. (orig.) [de

  15. Cosmic ray spectroscopy using plastic scintillator detector

    International Nuclear Information System (INIS)

    Rudra, Sharmili; Nandan, Akhilesh P.; Neog, Himangshu; Biswas, S.; Mohanty, B.; Mahapatra, S.; Samal, P.K.

    2014-01-01

    A simple and new technique has been developed using plastic scintillator detectors for cosmic ray spectroscopy without single channel analyzer (SCA) or multichannel analyzer (MCA). In this technique only a leading edge discriminator (LED) and a NIM scaler have been used. Plastic scintillator detectors has been used to measure the velocity of cosmic ray muons. Here the time difference has been measured from the Tektronix DPO 5054 digital phosphor oscilloscope with 500 MHz and 5 GS/s. The details of experimental technique, analysis procedure and experimental results are presented

  16. Cosmic Rays: studies and measurements before 1912

    Science.gov (United States)

    De Angelis, Alessandro

    2013-06-01

    The discovery of cosmic rays, a milestone in science, was based on the work by scientists in Europe and the New World and took place during a period characterised by nationalism and lack of communication. Many scientists that took part in this research a century ago were intrigued by the penetrating radiation and tried to understand the origin of it. Several important contributions to the discovery of the origin of cosmic rays have been forgotten; historical, political and personal facts might have contributed to their substantial disappearance from the history of science.

  17. Cosmic Rays: studies and measurements before 1912

    International Nuclear Information System (INIS)

    De Angelis, Alessandro

    2013-01-01

    The discovery of cosmic rays, a milestone in science, was based on the work by scientists in Europe and the New World and took place during a period characterised by nationalism and lack of communication. Many scientists that took part in this research a century ago were intrigued by the penetrating radiation and tried to understand the origin of it. Several important contributions to the discovery of the origin of cosmic rays have been forgotten; historical, political and personal facts might have contributed to their substantial disappearance from the history of science

  18. Cosmic Ray Acceleration in Supernova Remnants

    International Nuclear Information System (INIS)

    O'C Drury, Luke

    2005-01-01

    This paper describes some recent developments in our understanding of cosmic ray acceleration in supernova remnant shocks. It is pointed out that while good agreement now exists as to steady nonlinear modifications to the shock structure, there is also growing evidence that the mesoscopic scales may not in fact be steady and that significant instabilities associated with magnetic field amplification may be a feature of strong collisionless plasma shocks. There is strong observational evidence for such magnetic field amplification, and it appears to solve a number of long-standing issues concerned with acceleration of cosmic rays in supernova remnants

  19. Search for antimatter in primary cosmic rays.

    Science.gov (United States)

    Buffington, A.; Smith, L. H.; Smoot, G. F.; Alvarez, L. W.; Wahlig, M. A.

    1972-01-01

    Data from two flights of a new superconducting magnetic spectrometer are reported. This instrument was capable of a direct matter-antimatter separation in the cosmic rays. Antimatter events would appear in the spectrometer as trajectories which curve in the opposite direction to common matter, because of their negative charge. A brief description of the equipment and of the characteristics of the instrument is presented, along with the data processing techniques used. A new upper limit on the amount of antimatter in primary cosmic rays has been established. The limits are considerably lower than those for any previous experiment.

  20. Analysis of the low energy neutron inelastic scattering in mass range 48≤A≤64

    International Nuclear Information System (INIS)

    Cabezas, R.; Lubian, J.; Tomas, J.

    1990-04-01

    An analysis of low energy neutron inelastic scattering in medium-mass nuclei is made. A regional deformed optical model parameterization is proposed to describe the experimental data. This parameterization is derived from titanium, chromium, iron and nickel isotopes in the energy region of 1-3 MeV. A combined use of the coupled channel method and the statistical Hauser-Feshbach theory including corrections due to the presence of direct processes is applied. It is shown that, in the frame of this parameterization, it is possible to describe adequately experimental angular distributions, integral and total cross sections. An extrapolation to the energy region higher than 3 MeV is made. It is also shown, that this parameterization can be extended to other neighbour nuclei like zinc isotopes 64,66,68 Zn. (author). 41 refs, 44 figs

  1. Glass-like, low-energy excitations in neutron-irradiated quartz

    International Nuclear Information System (INIS)

    Gardner, J.W.

    1980-01-01

    The specific heat and thermal conductivity of neutron-irradiated crystalline quartz have been measured for temperatures approx. = 0.1 to 5 K. Four types of low-energy excitations are observed in the irradiated samples, two of which can be removed selectively by heat treatment. One set of remaining excitations gives rise to low-temperature thermal behavior characteristic of glassy (amorphous) solids. The density of these glass-like excitations can be 50% the density observed in vitreous silica, yet the sample still retains long-range atomic order. In a less-irradiated sample, glass-like excitations may be present with a density only approx. = 2.5% that observed in vitreous silica and possess a similar broad energy spectrum over 0.1 to 1 K

  2. Cosmic Rays Report from the Structure of Space

    Directory of Open Access Journals (Sweden)

    A. Annila

    2015-01-01

    Full Text Available Spectrum of cosmic rays follows a broken power law over twelve orders of magnitude. Since ubiquitous power laws are manifestations of the principle of least action, we interpret the spectrum accordingly. Our analysis complies with understanding that low-energy particles originate mostly from rapidly receding sources throughout the cosmos. The flux peaks about proton rest energy whereafter it decreases because fewer and fewer receding sources are energetic enough to provide particles with high enough velocities to compensate for the recessional velocities. Above 1015.6 eV the flux from the expanding Universe diminishes below the flux from the nearby nonexpanding part of the Universe. In this spectral feature, known as the “knee,” we relate to a distance of about 1.3 Mpc where the gravitational potential tallies the energy density of free space. At higher energies particles decelerate in a dissipative manner to attain thermodynamic balance with the vacuum. At about 1017.2 eV a distinct dissipative mechanism opens up for protons to slow down by electron-positron pair production. At about 1019.6 eV a more effective mechanism opens up via pion production. All in all, the universal principle discloses that the broad spectrum of cosmic rays probes the structure of space from cosmic distances down to microscopic details.

  3. On the idea of low-energy nuclear reactions in metallic lattices by producing neutrons from protons capturing "heavy" electrons

    Science.gov (United States)

    Tennfors, Einar

    2013-02-01

    The present article is a critical comment on Widom and Larsens speculations concerning low-energy nuclear reactions (LENR) based on spontaneous collective motion of protons in a room temperature metallic hydride lattice producing oscillating electric fields that renormalize the electron self-energy, adding significantly to the effective electron mass and enabling production of low-energy neutrons. The frequency and mean proton displacement estimated on the basis of neutron scattering from protons in palladium and applied to the Widom and Larsens model of the proton oscillations yield an electron mass enhancement less than one percent, far below the threshold for the proposed neutron production and even farther below the mass enhancement obtained by Widom and Larsen assuming a high charge density. Neutrons are not stopped by the Coulomb barrier, but the energy required for the neutron production is not low.

  4. Current Status of Astrophysics of Cosmic Rays

    Science.gov (United States)

    Moskalenko, Igor

    2016-03-01

    I will review the current instrumentation and recent results. I will discuss which measurements have to be done in the near future to significantly advance our knowledge about the phenomenon of cosmic rays, their sources, and their interactions with the interstellar medium. A support from NASA APRA Grant No. NNX13AC47G is greatly acknowledged.

  5. 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.)

  6. 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

  7. 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

  8. 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…

  9. Periodic and recurrent variations of cosmic rays

    International Nuclear Information System (INIS)

    Somogyi, A.J.

    1981-12-01

    The new results achieved in the field of periodic and recurrent variations of the intensity of 10 9 to 10 13 eV cosmic rays are reviewed. Particular emphasis is given to developments in understanding the fluctuations of corotation-type anisotropies as well as to the structure of the heliosphere and its temporal changes. (author)

  10. Cosmic ray muons in the deep ocean

    Energy Technology Data Exchange (ETDEWEB)

    Babson, J.; Becker-Szenzy, R.; Cady, R.; Dye, S.; Gorham, P.; Learned, J.; Matsuno, S.; O' Conner, D.; Peterson, V.; Roberts, A.; Stenger, V. (Hawaii Univ., Honolulu (USA)); Barish, B. (California Inst. of Tech., Pasadena (USA)); Bradner, H. (California Univ., San Diego, La Jolla (USA)); Clem, J.; Roos, C.; Webster, M. (Vanderbilt Univ., Nashville, TN (USA)); Gaidos, J.; Wilson, C. (Purdue Univ., Lafayette, IN (USA)); Grieder, P. (Bern Univ. (Switzerland)); Kitamura, T.; Mitsui, K.; Ohashi, Y.; Okada, A. (Tokyo Univ. (Japan). Inst. for Cosmic Ray Research); Kropp, W.; Price, L.; Reines, F.; Sobel, H. (California Univ., Irvine (USA)); March, R. (Wisconsin Univ., Madison (USA)); DUMAND Collaboration

    1990-03-01

    A measurement of cosmic ray muon flux was obtained at ocean depths ranging from 2 km to 4 km at 500 m intervals off the West Coast of the Big Island of Hawaii. A brief description of the experiment and the results will be presented in this paper. (orig.).

  11. 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.

  12. 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.)

  13. Low cloud properties influenced by cosmic rays

    Science.gov (United States)

    Marsh; Svensmark

    2000-12-04

    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 (climate on Earth.

  14. Capturing the most energetic cosmic rays

    International Nuclear Information System (INIS)

    Mantsch, P.

    1999-01-01

    The methods of energy measurement applied to the most energetic cosmic rays are described. The rays are so rare that two gigantic systems of detectors are proposed to detect at least some of them (the Pierre Auger Project ). (Z.J.)

  15. Underground cosmic-ray experiment EMMA

    DEFF Research Database (Denmark)

    Kuusiniemi, P.; Bezrukov, L.; Enqvist, T.

    2013-01-01

    EMMA (Experiment with MultiMuon Array) is a new approach to study the composition of cosmic rays at the knee region (1 – 10 PeV). The array will measure the multiplicity and lateral distribution of the high-energy muon component of an air shower and its arrival direction on an event-by-event basis...

  16. Believability of signals from cosmic ray sources

    International Nuclear Information System (INIS)

    Goodman, M.

    1990-11-01

    This paper discusses some of the criteria by which an observer judges whether to believe a signal or limit that has been reported for a cosmic ray source. The importance of specifying the test before looking at the data is emphasized. 5 refs

  17. The Global Survey Method Applied to Ground-level Cosmic Ray Measurements

    Science.gov (United States)

    Belov, A.; Eroshenko, E.; Yanke, V.; Oleneva, V.; Abunin, A.; Abunina, M.; Papaioannou, A.; Mavromichalaki, H.

    2018-04-01

    The global survey method (GSM) technique unites simultaneous ground-level observations of cosmic rays in different locations and allows us to obtain the main characteristics of cosmic-ray variations outside of the atmosphere and magnetosphere of Earth. This technique has been developed and applied in numerous studies over many years by the Institute of Terrestrial Magnetism, Ionosphere and Radiowave Propagation (IZMIRAN). We here describe the IZMIRAN version of the GSM in detail. With this technique, the hourly data of the world-wide neutron-monitor network from July 1957 until December 2016 were processed, and further processing is enabled upon the receipt of new data. The result is a database of homogeneous and continuous hourly characteristics of the density variations (an isotropic part of the intensity) and the 3D vector of the cosmic-ray anisotropy. It includes all of the effects that could be identified in galactic cosmic-ray variations that were caused by large-scale disturbances of the interplanetary medium in more than 50 years. These results in turn became the basis for a database on Forbush effects and interplanetary disturbances. This database allows correlating various space-environment parameters (the characteristics of the Sun, the solar wind, et cetera) with cosmic-ray parameters and studying their interrelations. We also present features of the coupling coefficients for different neutron monitors that enable us to make a connection from ground-level measurements to primary cosmic-ray variations outside the atmosphere and the magnetosphere. We discuss the strengths and weaknesses of the current version of the GSM as well as further possible developments and improvements. The method developed allows us to minimize the problems of the neutron-monitor network, which are typical for experimental physics, and to considerably enhance its advantages.

  18. 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

  19. Low-energy Coulomb excitation of neutron-rich zinc isotopes

    CERN Document Server

    Van de Walle, J; Behrens, T; Bildstein, V; Blazhev, A; Cederkäll, J; Clément, E; Cocolios, T E; Davinson, T; Delahaye, P; Eberth, J; Ekström, A; Fedorov, D V; Fedosseev, V; Fraile, L M; Franchoo, S; Gernhäuser, R; Georgiev, G; Habs, D; Heyde, K; Huber, G; Huyse, M; Ibrahim, F; Ivanov, O; Iwanicki, J; Jolie, J; Kester, O; Köster, U; Kröll, T; Krücken, R; Lauer, M; Lisetskiy, A F; Lutter, R; Marsh, B A; Mayet, P; Niedermaier, O; Pantea, M; Raabe, R; Reiter, P; Sawicka, M; Scheit, H; Schrieder, G; Schwalm, D; Seliverstov, M D; Sieber, T; Sletten, G; Smirnova, N; Stanoiu, M; Stefanescu, I; Thomas, J C; Valiente-Dobón, J J; Van Duppen, P; Verney, D; Voulot, D; Warr, N; Weisshaar, D; Wenander, F; Wolf, B H; Zielinska, M

    2009-01-01

    At the radioactive ion beam facility REX-ISOLDE, neutron-rich zinc isotopes were investigated using low-energy Coulomb excitation. These experiments have resulted in B(E2,20) values in 74-80Zn, B(E2,42) values in 74,76Zn and the determination of the energy of the first excited 2 states in 78,80Zn. The zinc isotopes were produced by high-energy proton- (A=74,76,80) and neutron- (A=78) induced fission of 238U, combined with selective laser ionization and mass separation. The isobaric beam was postaccelerated by the REX linear accelerator and Coulomb excitation was induced on a thin secondary target, which was surrounded by the MINIBALL germanium detector array. In this work, it is shown how the selective laser ionization can be used to deal with the considerable isobaric beam contamination and how a reliable normalization of the experiment can be achieved. The results for zinc isotopes and the N=50 isotones are compared to collective model predictions and state-of-the-art large-scale shell-model calculations, i...

  20. Transient phenomena in cosmic ray intensity during extreme events

    Science.gov (United States)

    Agarwal, Rekha; Mishra, Rajesh K.

    2008-04-01

    In the present work an analysis has been made of the extreme events occurring during July 2005. Specifically, a rather intense Forbush decrease was observed at different neutron monitors all over the world during 16 July 2005. An effort has been made to study the effect of this unusual event on cosmic ray intensity as well as various solar and interplanetary plasma parameters. It is noteworthy that during 11 to 18 July 2005 the solar activity ranged from low to very active. Especially low levels occurred on 11, 15, and 17 July whereas high levels took place on 14 and 16 July 2005. The Sun is observed to be active during 11 to 18 July 2005, the interplanetary magnetic field intensity lies within 15 nT, and solar wind velocity was limited to ˜500 kms-1. The geomagnetic activity during this period remains very quiet, the Kp index did not exceed 5, the disturbance storm time Dst index remains ˜-70 nT and no sudden storm commencement has been detected during this period. It is noted that for the majority of the hours, the north/south component of the interplanetary magnetic field, Bz, remains negative, and the cosmic ray intensity increases and shows good/high correlation with Bz, as the polarity of Bz tends to shift from negative to positive values, the intensity decreases and shows good/high anti-correlation with Bz. The cosmic ray intensity tends to decrease with increase of interplanetary magnetic field strength (B) and shows anti-correlation for the majority of the days.

  1. Ecological and hydrological monitoring of the natural environment with help of cosmic rays

    International Nuclear Information System (INIS)

    Oskomov, V.V.

    2001-01-01

    It is noted that with help cosmic ray it is possible measuring the contaminating element concentration in the atmosphere, near surface water layer, and soil by characteristic radiation of elements generated by cosmic rays. With aim of determination of hydrological and glaciology characteristics of glaciers and snow cover of mountain districts the method for moisture store determination in the substance with help of natural ionizing radiation were used. With help of automate remote system including a set of detectors for muons, neutrons and gamma quanta, and others ones placed near researched medium the ecological and hydrological monitoring is worked out

  2. 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.

  3. Feasibility study on a cosmic-ray level gauge

    International Nuclear Information System (INIS)

    Matsuda, H.; Fukaya, M.; Minato, S.

    1989-01-01

    Cosmic-ray intensities were measured at the stairs in a subway station in Nagoya City, inside a tall concrete building and under a cylindrical water tank, to examine the feasibility of a cosmic-ray level gauge. The measured results agreed quite well with the theoretical calculations. These results show that a cosmic-ray level gauge is feasible. (author)

  4. Cosmic Rays Astrophysics: The Discipline, Its Scope, and Its Applications

    Science.gov (United States)

    Barghouty, A. F.

    2009-01-01

    This slide presentation gives an overview of the discipline surrounding cosmic ray astrophysics. It includes information on recent assertions surrounding cosmic rays, exposure levels, and a short history with specific information on the origin, acceleration, transport, and modulation of cosmic rays.

  5. The Los Alamos Neutron Science Center Spallation Neutron Sources

    International Nuclear Information System (INIS)

    Nowicki, Suzanne F.; Wender, Stephen A.; Mocko, Michael

    2017-01-01

    The Los Alamos Neutron Science Center (LANSCE) provides the scientific community with intense sources of neutrons, which can be used to perform experiments supporting civilian and national security research. These measurements include nuclear physics experiments for the defense program, basic science, and the radiation effect programs. This paper focuses on the radiation effects program, which involves mostly accelerated testing of semiconductor parts. When cosmic rays strike the earth's atmosphere, they cause nuclear reactions with elements in the air and produce a wide range of energetic particles. Because neutrons are uncharged, they can reach aircraft altitudes and sea level. These neutrons are thought to be the most important threat to semiconductor devices and integrated circuits. The best way to determine the failure rate due to these neutrons is to measure the failure rate in a neutron source that has the same spectrum as those produced by cosmic rays. Los Alamos has a high-energy and a low-energy neutron source for semiconductor testing. Both are driven by the 800-MeV proton beam from the LANSCE accelerator. The high-energy neutron source at the Weapons Neutron Research (WNR) facility uses a bare target that is designed to produce fast neutrons with energies from 100 keV to almost 800 MeV. The measured neutron energy distribution from WNR is very similar to that of the cosmic-ray-induced neutrons in the atmosphere. However, the flux provided at the WNR facility is typically 5×107 times more intense than the flux of the cosmic-ray-induced neutrons. This intense neutron flux allows testing at greatly accelerated rates. An irradiation test of less than an hour is equivalent to many years of neutron exposure due to cosmic-ray neutrons. The low-energy neutron source is located at the Lujan Neutron Scattering Center. It is based on a moderated source that provides useful neutrons from subthermal energies to ~100 keV. The characteristics of these sources

  6. The Los Alamos Neutron Science Center Spallation Neutron Sources

    Science.gov (United States)

    Nowicki, Suzanne F.; Wender, Stephen A.; Mocko, Michael

    The Los Alamos Neutron Science Center (LANSCE) provides the scientific community with intense sources of neutrons, which can be used to perform experiments supporting civilian and national security research. These measurements include nuclear physics experiments for the defense program, basic science, and the radiation effect programs. This paper focuses on the radiation effects program, which involves mostly accelerated testing of semiconductor parts. When cosmic rays strike the earth's atmosphere, they cause nuclear reactions with elements in the air and produce a wide range of energetic particles. Because neutrons are uncharged, they can reach aircraft altitudes and sea level. These neutrons are thought to be the most important threat to semiconductor devices and integrated circuits. The best way to determine the failure rate due to these neutrons is to measure the failure rate in a neutron source that has the same spectrum as those produced by cosmic rays. Los Alamos has a high-energy and a low-energy neutron source for semiconductor testing. Both are driven by the 800-MeV proton beam from the LANSCE accelerator. The high-energy neutron source at the Weapons Neutron Research (WNR) facility uses a bare target that is designed to produce fast neutrons with energies from 100 keV to almost 800 MeV. The measured neutron energy distribution from WNR is very similar to that of the cosmic-ray-induced neutrons in the atmosphere. However, the flux provided at the WNR facility is typically 5×107 times more intense than the flux of the cosmic-ray-induced neutrons. This intense neutron flux allows testing at greatly accelerated rates. An irradiation test of less than an hour is equivalent to many years of neutron exposure due to cosmic-ray neutrons. The low-energy neutron source is located at the Lujan Neutron Scattering Center. It is based on a moderated source that provides useful neutrons from subthermal energies to ∼100 keV. The characteristics of these sources, and

  7. 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.

  8. The neutron and low-energy gamma operational dosimetry in Melox plant

    International Nuclear Information System (INIS)

    Devita, A.D.

    2006-01-01

    M.E.L.O.X., subsidiary of A.R.E.V.A., produce M.O.X. fuels, a mixture of uranium and plutonium oxides. With the use in the process of plutonium oxide, there is a risk of external exposure to neutrons and low -energy gamma rays. By their characteristics, both these types of radiation are difficult to measure. The difficulty in measuring neutron doses lies in the fact that the fluence -to-dose equivalent conversion factor varies with the neutron energy level. In low -energy gamma (between 20 and 60 keV) dose measurement, the problem is detection using an electronic system. Just some years ago, very few industrial players were tempted to develop dosimeters in these areas in view of the poor demand and market prospects. Furthermore, radiation protection specialists needed a highly functional and robust direct reading dosimeters or, in other words, a device that was simple, reliable, inexpensive, small, and quick and easy to use in a wide range of working environments that could vary in terms of both the workstation and external exposure. In addition, at sites such as Melox, where company employees work alongside personnel from outside companies, the same types of dosimeters must be used so that dose -related data can be managed globally in one data base. Two technical solutions are available for neutron operational dosimetry - spectrometer-dosimeters and calibration dosimeters. Melox has opted for the use of calibration dosimeters. The reasons for this choice (technical, financial and organizational criteria) are given in this presentation. Before and during the various campaigns of M.O.X. fuels, the spectral characteristics relating to neutron fluence at different workstations and representative of personnel exposure levels were determined. A reference spectrometer was then used to determine the transfer function between fluence and dose in order to calibrate passive and operational dosimeters appropriately.The methodology to be set up should guarantee good

  9. Acceleration and propagation of cosmic rays. Production, oscillation and detection of neutrinos

    International Nuclear Information System (INIS)

    Lagage, P.O.

    1987-01-01

    This thesis is devoted to studies on cosmic rays and neutrinos, particles astrophysically relevant. In recent years, the old problem of cosmic-ray acceleration and propagation has become alive again, with the discovery of the diffusive shock acceleration mechanism, and with the first measurements of the cosmic-ray antiproton flux, which appears to be higher than expected. I have shown that the new acceleration mechanism was slow and I have calculated the maximum energy that can be reached by particles accelerated in various astrophysical sites. I have also studied in detail a cosmic-ray propagation model which takes into account the antiproton measurements. Neutrino astronomy is a field much more recent and in rapid expansion, thanks to a convergence of interests between astrophysicists and elementary particle physicists. Several large neutrino detectors already exist; really huge ones are in project. I have studied the possible impact of the high energy (> 1 TeV) neutrino astronomy on models of cosmic-ray sources such as Cygnus X3. Comparing the low energy (∼ 10 MeV) cosmic-ray antineutrinos with other sources of neutrinos and antineutrinos (sun, supernova, earth ...), I have pointed out that the antineutrino background resulting from all the nuclear power-stations of the planet was sizeable. This background is a nuisance for some astrophysical applications but could be useful for studies on vacuum or matter neutrino oscillations (MSW effect). I have also examined the MSW effect in another context: the travel through the earth of neutrinos from the supernova explosion SN1987a [fr

  10. 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.

  11. 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.

  12. Evidence from cosmic ray exposure (CRE) dating for the existence of a pre-Minoan caldera on Santorini, Greece

    Science.gov (United States)

    Athanassas, C. D.; Bourlès, D. L.; Braucher, R.; Druitt, T. H.; Nomikou, P.; Léanni, L.

    2016-05-01

    Cosmic ray exposure (CRE) dating was performed on the caldera cliffs of Santorini with the aim of detecting cliff segments predating the Minoan eruption (17th century BCE). The methodology involved the determination of in situ-produced cosmogenic 36Cl concentration in basaltic-to-rhyodacitic whole rocks cropping out in the cliffs. After the samples were processed following the chemical protocol of 36Cl preparation for silicate rocks, 36Cl concentrations were measured by accelerator mass spectrometry (AMS). Important challenges during the implementation procedure were related to large amounts of radiogenic 36Cl, complex modeling of inherited 36Cl, and dominance of the thermal and epithermal (low-energy) neutron capture production pathway. Nevertheless, quantitative assessments on the basis of the contribution of the low-energy neutron capture pathway percent to the total production rate validated the calculated CRE dates. Current CRE ages demonstrate that an ancient caldera existed on pre-Minoan Santorini, occupying at least the northern half of the modern-day caldera.

  13. 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.

  14. 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.)

  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. PRECISE COSMIC RAYS MEASUREMENTS WITH PAMELA

    Directory of Open Access Journals (Sweden)

    A. Bruno

    2013-12-01

    Full Text Available The PAMELA experiment was launched on board the Resurs-DK1 satellite on June 15th 2006. The apparatus was designed to conduct precision studies of charged cosmic radiation over a wide energy range, from tens of MeV up to several hundred GeV, with unprecedented statistics. In five years of continuous data taking in space, PAMELA accurately measured the energy spectra of cosmic ray antiprotons and positrons, as well as protons, electrons and light nuclei, sometimes providing data in unexplored energetic regions. These important results have shed new light in several astrophysical fields like: an indirect search for Dark Matter, a search for cosmological antimatter (anti-Helium, and the validation of acceleration, transport and secondary production models of cosmic rays in the Galaxy. Some of the most important items of Solar and Magnetospheric physics were also investigated. Here we present the most recent results obtained by the PAMELA experiment.

  17. 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

  18. 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.)

  19. Cosmic rays, solar activity and the climate

    International Nuclear Information System (INIS)

    Sloan, T; Wolfendale, A W

    2013-01-01

    Although it is generally believed that the increase in the mean global surface temperature since industrialization is caused by the increase in green house gases in the atmosphere, some people cite solar activity, either directly or through its effect on cosmic rays, as an underestimated contributor to such global warming. In this letter a simplified version of the standard picture of the role of greenhouse gases in causing the global warming since industrialization is described. The conditions necessary for this picture to be wholly or partially wrong are then introduced. Evidence is presented from which the contributions of either cosmic rays or solar activity to this warming is deduced. The contribution is shown to be less than 10% of the warming seen in the twentieth century. (letter)

  20. The glacial cycles and cosmic rays

    CERN Document Server

    Kirkby, Jasper; Müller, R A

    2004-01-01

    The cause of the glacial cycles remains a mystery. The origin is widely accepted to be astronomical since paleoclimatic archives contain strong spectral components that match the frequencies of Earth's orbital modulation. Milankovitch insolation theory contains similar frequencies and has become established as the standard model of the glacial cycles. However, high precision paleoclimatic data have revealed serious discrepancies with the Milankovitch model that fundamentally challenge its validity and re-open the question of what causes the glacial cycles. We propose here that the ice ages are initially driven not by insolation cycles but by cosmic ray changes, probably through their effect on clouds. This conclusion is based on a wide range of evidence, including results presented here on speleothem growth in caves in Austria and Oman, and on a record of cosmic ray flux over the past 220 kyr obtained from the 10Be composition of deep-ocean sediments.

  1. Cosmic rays and radiations from the cosmos

    International Nuclear Information System (INIS)

    Parizot, E.

    2005-12-01

    This document gathers a lot of recent information concerning cosmic radiations, it is divided into 4 parts. Part I: energy, mass and angular spectra of cosmic rays. Part II: general phenomenology of cosmic rays, this part deals with the standard model, the maximal energy of protons inside supernova remnants, nucleosynthesis of light elements, and super-bubbles. Part III: radiations from the cosmos, this part deals with high energy gamma rays, non-thermal radiation of super-bubbles, positron transport, and the Compton trail of gamma-ray bursts. Part IV: the Pierre Auger observatory (OPA), this part deals with the detection of gamma ray bursts at OPA, the measurement of anisotropy, and top-down models. (A.C.)

  2. Search for cosmic-ray antimatter

    International Nuclear Information System (INIS)

    Smoot, G.F.; Buffington, A.; Orth, C.D.

    1975-01-01

    In a sample of 1.5times10 4 helium and 4.0times10 4 higher-charged nuclei, obtained with balloon-borne superconducting magnetic spectrometers, we find the ratio of antinuclei to nuclei in the cosmic rays to be less than 8times10 -5 for rigidities (momentum/charge) between 4 and 33 GV/c and less than 10 -2 between 33 and 100 GV/c, at the 95% confidence level. (auth)

  3. Electron capture isotopes as cosmic ray 'hydrometers'

    International Nuclear Information System (INIS)

    Raisbeck, G.M.; Comstock, G.; Perron, C.; Yiou, F.

    1975-01-01

    Following our earlier work, a computer program has been developed to investigate in detail the survival of pure electron capture isotopes in cosmic rays as a function of their propagation conditions. It is found that this survival is very insensitive to certain parameters such as the type of path length distribution, but very sensitive to the density of the medium in which they are formed. Observation of these isotopes may thus provide clues as to this density. (orig.) [de

  4. Origin of transient cosmic ray intensity variations

    International Nuclear Information System (INIS)

    Duggal, S.P.; Pomerantz, M.A.

    1977-01-01

    A new approach to determining the solar progenitor of transient cosmic ray intensity variations has revealed that in a statistical sense, solar flares, heretofore regarded as the predominant source of the modulation, actually do not precede the reduction in flux observed at earth. Superposed epoch analysis of the cosmic ray data with respect to the time of occurrence of all 379 solar flares of importance (Imp) < or =2 observed during solar cycle 20 (1964-1974 inclusive) shows that the onset of a decrease in the composite nucleonic intensity at polar stations occurs prior to the zero day (i.e., time of the flare) well before the arrival in the vicinity of earth of the associated solar plasma. The statistical significance of this result is confirmed by comparing the pooled variance determined from Chree analysis of an equal number of random epochs with that of the curve representing the flare epochs. Subdivision of the latter into three groups according to the heliographic longitude of the flares shows that whereas eastern flares might be associated with cosmic ray decreases, central (30degree to -30degree) and western flares cannot be thus related. A similar analysis of all flares of Imp< or =2 that occurred in a selected set of 24 extraordinary flare-rich active centers during 1964--1974 confirms these results and shows that the observed cosmic ray intensity decrease is, in fact, associated with the central meridian passage ( +- 1 day) of the active regions. Thus earlier conclusions concerning relationships between the heliolongitude of flares and their apparent effectiveness in producing Forbush decreases require reevaluation. The specific feature associated with solar active centers that is actually the principal source of transient modulations remanins to be identified

  5. 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

  6. Search for cosmic-ray antimatter

    Science.gov (United States)

    Smoot, G. F.; Buffington, A.; Orth, C. D.

    1975-01-01

    It appears probable that some fraction of the cosmic rays has extragalactic origin. A search for antimatter nuclei was conducted with the aid of a balloon-borne superconducting magnetic spectrometer. The investigation made use of the fact that matter and antimatter nuclei, because of their opposite signs of charge, would be deflected in opposite directions when passing through a magnetic field. The antimatter flux limits set by the experiments are discussed.

  7. 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

  8. Cosmic ray variations of solar origin in relation to human physiological state during the December 2006 solar extreme events

    Science.gov (United States)

    Papailiou, M.; Mavromichalaki, H.; Vassilaki, A.; Kelesidis, K. M.; Mertzanos, G. A.; Petropoulos, B.

    2009-02-01

    There is an increasing amount of evidence linking biological effects to solar and geomagnetic disturbances. A series of studies is published referring to the changes in human physiological responses at different levels of geomagnetic activity. In this study, the possible relation between the daily variations of cosmic ray intensity, measured by the Neutron Monitor at the Cosmic Ray Station of the University of Athens (http://cosray.phys.uoa.gr) and the average daily and hourly heart rate variations of persons, with no symptoms or hospital admission, monitored by Holter electrocardiogram, is considered. This work refers to a group of persons admitted to the cardiological clinic of the KAT Hospital in Athens during the time period from 4th to 24th December 2006 that is characterized by extreme solar and geomagnetic activity. A series of Forbush decreases started on 6th December and lasted until the end of the month and a great solar proton event causing a Ground Level Enhancement (GLE) of the cosmic ray intensity on 13th December occurred. A sudden decrease of the cosmic ray intensity on 15th December, when a geomagnetic storm was registered, was also recorded in Athens Neutron Monitor station (cut-off rigidity 8.53 GV) with amplitude of 4%. It is noticed that during geomagnetically quiet days the heart rate and the cosmic ray intensity variations are positively correlated. When intense cosmic ray variations, like Forbush decreases and relativistic proton events produced by strong solar phenomena occur, cosmic ray intensity and heart rate get minimum values and their variations, also, coincide. During these events the correlation coefficient of these two parameters changes and follows the behavior of the cosmic ray intensity variations. This is only a small part of an extended investigation, which has begun using data from the year 2002 and is still in progress.

  9. 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)

  10. 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

  11. Cosmic Ray Data in TRT Barrel

    CERN Multimedia

    M. Hance

    "I had a great day in August when I went into SR1," said Daniel Froidevaux, former project leader of the ATLAS Transition Radiation Tracker, "not only had all SCT barrels arrived at CERN, but there were cosmic ray tracks seen in the TRT!" Daniel's excitement was mirrored by the rest of the TRT collaboration when, on July 29, the first cosmic ray tracks were seen in the barrel. Along with many others in the community, Daniel was quick to point out that this is the cumulative result of years of R&D, test beam work, and an intense installation and integration schedule. Indeed, the cosmic ray readout is only possible through the coordination of many efforts, from detector mechanics to module assembly, power and high voltage control, cooling, gas systems, electronics and cabling, data acquisition, and monitoring. "Many people have worked very hard on the the TRT, some of them for more than 10 years," said Brig Williams, the leader of the UPenn group responsible for much of the TRT front end electronics. He ...

  12. 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

  13. 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

  14. 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

  15. Search for Cosmic-Ray Antiproton Origins and for Cosmological Antimatter with BESS

    Science.gov (United States)

    Yamamoto, A.; Mitchell, J. W.; Yoshimura, K.; Abe, K.; Fuke, H.; Haino, S.; Hams, T.; Hasegawa, M.; Horikoshi, A.; Itazaki, A.; hide

    2011-01-01

    The balloon-borne experiment with a superconducting spectrometer (BESS) has performed cosmic-ray observations as a US-Japan cooperative space science program, and has provided fundamental data on cosmic rays to study elementary particle phenomena in the early Universe. The BESS experiment has measured the energy spectra of cosmic-ray antiprotons to investigate signatures of possible exotic origins such as dark matter candidates or primordial black holes. and searched for heavier antinuclei that might reach Earth from antimatter domains formed in the early Universe. The apex of the BESS program was reached with the Antarctic flight of BESS-Polar II, during the 2007- 2008 Austral Summer, that obtained over 4.7 billion cosmic-ray events from 24.5 days of observation. The flight took place at the expected solar minimum, when the sensitivity of the low-energy antiproton measurements to a primary source is greatest. Here, we report the scientific restults, focusing on the long-duration flights of BESS-Polar I (2004) and BESS-Polar II (2007-2008).

  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. Latitudinal and longitudinal dependence of the cosmic ray diurnal anisotropy during 2001-2014

    International Nuclear Information System (INIS)

    Tezari, Anastasia; Mavromichalaki, Helen; Katsinis, Dimitrios; Kanellakopoulos, Anastasios; Kolovi, Sofia; Plainaki, Christina; National and Kapodistrian Univ. of Athens; Andriopoulou, Maria

    2016-01-01

    The diurnal anisotropy of cosmic ray intensity for the time period 2001 to 2014 is studied, covering the maximum and the descending phase of solar cycle 23, the minimum between solar cycles 23 and 24, and the ascending phase and maximum of solar cycle 24. Cosmic ray intensity data from 11 neutron monitor stations located at different places around the Northern Hemisphere obtained from the high-resolution Neutron Monitor Database (NMDB) were used. Special software was developed for the calculations of the amplitude and the phase of the diurnal anisotropy vectors on annual and monthly basis using Fourier analysis and for the creation of the harmonic dial diagrams. The geomagnetic bending for each station was taken into account in our calculations determined from the asymptotic cones of each station via the Tsyganenko96 (Tsyganenko and Stern, 1996) magnetospheric model. From our analysis, it was resulted that there is a different behavior of the diurnal anisotropy vectors during the different phases of the solar cycles depending on the solar magnetic field polarity. The latitudinal and longitudinal distribution of the cosmic ray diurnal anisotropy was also examined by grouping the stations according to their geographic coordinates, and it was shown that diurnal variation is modulated not only by the latitude but also by the longitude of the stations. The diurnal anisotropy during strong events of solar and/or cosmic ray activity is discussed.

  18. Latitudinal and longitudinal dependence of the cosmic ray diurnal anisotropy during 2001-2014

    Energy Technology Data Exchange (ETDEWEB)

    Tezari, Anastasia; Mavromichalaki, Helen; Katsinis, Dimitrios; Kanellakopoulos, Anastasios; Kolovi, Sofia [National and Kapodistrian Univ. of Athens (Greece). Nuclear and Particle Physics Dept.; Plainaki, Christina [INAF-IAPS, Rome (Italy); National and Kapodistrian Univ. of Athens (Greece). Nuclear and Particle Physics Dept.; Andriopoulou, Maria [Austrian Academy of Sciences, Graz (Austria). Space Research Inst.

    2016-07-01

    The diurnal anisotropy of cosmic ray intensity for the time period 2001 to 2014 is studied, covering the maximum and the descending phase of solar cycle 23, the minimum between solar cycles 23 and 24, and the ascending phase and maximum of solar cycle 24. Cosmic ray intensity data from 11 neutron monitor stations located at different places around the Northern Hemisphere obtained from the high-resolution Neutron Monitor Database (NMDB) were used. Special software was developed for the calculations of the amplitude and the phase of the diurnal anisotropy vectors on annual and monthly basis using Fourier analysis and for the creation of the harmonic dial diagrams. The geomagnetic bending for each station was taken into account in our calculations determined from the asymptotic cones of each station via the Tsyganenko96 (Tsyganenko and Stern, 1996) magnetospheric model. From our analysis, it was resulted that there is a different behavior of the diurnal anisotropy vectors during the different phases of the solar cycles depending on the solar magnetic field polarity. The latitudinal and longitudinal distribution of the cosmic ray diurnal anisotropy was also examined by grouping the stations according to their geographic coordinates, and it was shown that diurnal variation is modulated not only by the latitude but also by the longitude of the stations. The diurnal anisotropy during strong events of solar and/or cosmic ray activity is discussed.

  19. On the continuous measurement of the cosmic-ray intensity, 2

    International Nuclear Information System (INIS)

    Ishida, Yoshio; Kanno, Tsunekichi

    1974-01-01

    Since November 1971, the cosmic ray neutron intensity has been measured continuously with 3NM-64 neutron monitor at Fukushima University (140 0 29'E geographic longitude, 37 0 45'N geographic latitude, 27.6 0 N geomagnetic latitude and 10.55 GV cut-off rigidity). After the neutron monitor had been operated during the period of fourteen months at the ground floor of 3-storied ferro-reinforced concrete building, it was removed to the prefabricated house near the old position of the monitor at January 1973. As a result of the removement of the monitor, the expected values for the counting rate and barometric coefficient of our neutron monitor were obtained, 7.5x10 4 cph and -0.64% mb respectively. The monitor was moved out into a new place, the statistical accuracy of counting rate is altered from 0.44% (hourly counting rate) to 0.36%. It can be considered that there is no effect of concrete building near the monitor, for reason that the zenith angle is opened more than 60 0 over the monitor. The difference between the new and the old measurement - measurement environments, intensities, barometric coefficient and others - were discussed. The continuous measurement of the cosmic ray neutron intensity at Fukushima will be kept on beaten track, and the obtained data of the cosmic ray neutron intensity (uncorrected, corrected intensity and barometric pressure) will be sent to WDC-C2 in form of monthly tables. (author)

  20. Empirical model for the Earth's cosmic ray shadow at 400 KM: prohibited cosmic ray access

    International Nuclear Information System (INIS)

    Humble, J.E.; Smart, D.F.; Shea, M.A.

    1985-01-01

    The possibility of constructing a unit sphere of access that describes the cosmic radiation allowed to an Earth-orbiting spacecraft is discussed. It is found that it is possible to model the occluded portion of the cosmic ray sphere of access as a circular projection with a diameter bounded by the satellite-Earth horizon. Maintaining tangency at the eastern edge of the spacecraft-Earth horizon, this optically occluded area is projected downward by an angle beta which is a function of the magnetic field inclination and cosmic ray arrival direction. This projected plane, corresponding to the forbidden area of cosmic ray access, is bounded by the spacecraft-Earth horizon in easterly directions, and is rotated around the vertical axis by an angle alpha from the eastern direction, where the angle alpha is a function of the offset dipole latitude of the spacecraft

  1. Production of low energy gamma rays by neutron interactions with fluorine for incident neutron energies between 0.1 and 20 MeV

    International Nuclear Information System (INIS)

    Morgan, G.L.; Dickens, J.K.

    1975-06-01

    Differential cross sections for the production of low-energy gamma rays (less than 240 keV) by neutron interactions in fluorine have been measured for neutron energies between 0.1 and 20 MeV. The Oak Ridge Electron Linear Accelerator was used as the neutron source. Gamma rays were detected at 92 0 using an intrinsic germanium detector. Incident neutron energies were determined by time-of-flight techniques. Tables are presented for the production cross sections of three gamma rays having energies of 96, 110, and 197 keV. (14 figures, 3 tables) (U.S.)

  2. 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.

  3. On scaling cosmogenic nuclide production rates for altitude and latitude using cosmic-ray measurements

    Science.gov (United States)

    Desilets, Darin; Zreda, Marek

    2001-11-01

    The wide use of cosmogenic nuclides for dating terrestrial landforms has prompted a renewed interest in characterizing the spatial distribution of terrestrial cosmic rays. Cosmic-ray measurements from neutron monitors, nuclear emulsions and cloud chambers have played an important role in developing new models for scaling cosmic-ray neutron intensities and, indirectly, cosmogenic production rates. Unfortunately, current scaling models overlook or misinterpret many of these data. In this paper, we describe factors that must be considered when using neutron measurements to determine scaling formulations for production rates of cosmogenic nuclides. Over the past 50 years, the overwhelming majority of nucleon flux measurements have been taken with neutron monitors. However, in order to use these data for scaling spallation reactions, the following factors must be considered: (1) sensitivity of instruments to muons and to background, (2) instrumental biases in energy sensitivity, (3) solar activity, and (4) the way of ordering cosmic-ray data in the geomagnetic field. Failure to account for these factors can result in discrepancies of as much as 7% in neutron attenuation lengths measured at the same location. This magnitude of deviation can result in an error on the order of 20% in cosmogenic production rates scaled from 4300 m to sea level. The shapes of latitude curves of nucleon flux also depend on these factors to a measurable extent, thereby causing additional uncertainties in cosmogenic production rates. The corrections proposed herein significantly improve our ability to transfer scaling formulations based on neutron measurements to scaling formulations applicable to spallation reactions, and, therefore, constitute an important advance in cosmogenic dating methodology.

  4. Antideuterons in cosmic rays: sources and discovery potential

    Energy Technology Data Exchange (ETDEWEB)

    Herms, Johannes; Ibarra, Alejandro; Vittino, Andrea; Wild, Sebastian, E-mail: johannes.herms@tum.de, E-mail: ibarra@tum.de, E-mail: andrea.vittino@tum.de, E-mail: sebastian.wild@ph.tum.de [Physik-Department T30d, Technische Universität München, James-Franck-Straße 1, D-85748 Garching (Germany)

    2017-02-01

    Antibaryons are produced in our Galaxy in collisions of high energy cosmic rays with the interstellar medium and in old supernova remnants, and possibly, in exotic sources such as primordial black hole evaporation or dark matter annihilations and decays. The search for signals from exotic sources in antiproton data is hampered by large backgrounds from spallation which, within theoretical errors, can solely account for the current data. Due to the higher energy threshold for antideuteron production, which translates into a suppression of the low energy flux from spallations, antideuteron searches have been proposed as a probe for exotic sources. We perform in this paper a comprehensive analysis of the antideuteron fluxes at the Earth expected from known and hypothetical sources in our Galaxy, and we calculate their maximal values consistent with current antiproton data from AMS-02. We find that supernova remnants generate a negligible flux, whereas primordial black hole evaporation and dark matter annihilations or decays may dominate the total flux at low energies. On the other hand, we find that the (detection of cosmic antideuterons) would require, for the scenarios studied in this paper and assuming optimistic values of the coalescence momentum and solar modulation, an increase of the experimental sensitivity compared to ongoing and planned instruments by at least a factor of 2. Finally, we briefly comment on the prospects for antihelium-3 detection.

  5. Meteorological effects in cosmic ray muon production

    International Nuclear Information System (INIS)

    Cutler, D.J.; Groom, D.E.

    1981-01-01

    A detailed study of atmospheric effects on cosmic ray muon intensity has been made in connection with the operation of the Utah 1500 GV Anisotropy Detector. Using standard linear regression methods, we find an anomalously small high altitude temperature coefficient and a high surface pressure coefficient. However, we understand the former as due to extraneous variance in the temperature data and the latter as due to correlations in the data. We also find that much or all of the 1/f behavior of the muon Fourier power spectrum at low frequencies appears to be due to high altitude temperature fluctuations

  6. Spectral features in the cosmic ray fluxes

    Science.gov (United States)

    Lipari, Paolo

    2018-01-01

    The cosmic ray energy distributions contain spectral features, that is narrow energy regions where the slope of the spectrum changes rapidly. The identification and study of these features is of great importance to understand the astrophysical mechanisms of acceleration and propagation that form the spectra. In first approximation a spectral feature is often described as a discontinuous change in slope, however very valuable information is also contained in its width, that is the length of the energy interval where the change in spectral index develops. In this work we discuss the best way to define and parameterize the width a spectral feature, and for illustration discuss some of the most prominent known structures.

  7. 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

  8. Cosmic Ray Physics with the IceCube Observatory

    International Nuclear Information System (INIS)

    Kolanoski, H

    2013-01-01

    The IceCube Neutrino Observatory with its 1-km 3 in-ice detector and the 1-km 2 surface detector (IceTop) constitutes a three-dimensional cosmic ray detector well suited for general cosmic ray physics. Various measurements of cosmic ray properties, such as energy spectra, mass composition and anisotropies, have been obtained from analyses of air showers at the surface and/or atmospheric muons in the ice.

  9. Celestial Messengers Cosmic Rays The Story of a Scientific Adventure

    CERN Document Server

    Bertolotti, Mario

    2013-01-01

    The book describes from a historical point of view how cosmic rays were discovered. The book describes the research in cosmic rays. The main focus is on how the knowledge was gained, describing the main experiments and the conclusions drawn. Biographical sketches of main researchers are provided. Cosmic rays have an official date of discovery which is linked to the famous balloon flights of the Austrian physicist Hess in 1912. The year 2012 can therefore be considered the centenary of the discovery.

  10. Celestial messengers. Cosmic rays. The story of a scientific adventure

    International Nuclear Information System (INIS)

    Bertolotti, Mario

    2013-01-01

    The book describes from a historical point of view how cosmic rays were discovered. The book describes the research in cosmic rays. The main focus is on how the knowledge was gained, describing the main experiments and the conclusions drawn. Biographical sketches of main researchers are provided. Cosmic rays have an official date of discovery which is linked to the famous balloon flights of the Austrian physicist Hess in 1912. The year 2012 can therefore be considered the centenary of the discovery.

  11. Cl36 and the age of the cosmic rays

    International Nuclear Information System (INIS)

    Casse, M.; Goret, P.; Regnier, S.

    1975-01-01

    The radioactive isotope 36 Cl (tau=γx3.10 5 y) is used as a time reference for the propagation of cosmic rays. New measurements of the production cross section of 36 Cl in Ti and Fe at 24GeV will be presented. A critical analysis of the cross sections leads to an estimate of the ratio 36 Cl/Cl=0.030+0.007 in the arriving cosmic rays. The comparison between the expected abundance of Cl in the arriving cosmic rays and the observations tend to support the decay of 36 Cl. The inferred cosmic ray confinement time is about 10 6 y [fr

  12. Cosmic ray intensity distribution in the vertical direction to solar equator plane

    International Nuclear Information System (INIS)

    Nosaka, Toru; Mori, Satoru; Sagisaka, Shuji.

    1983-01-01

    The data of the annual variation of cosmic ray intensity measured by neutron detectors were used to study the distribution of cosmic ray intensity vertical to the solar equator plane and its long term variation. The data used were obtained at Deep River, Kiel, Kerguelen Island, McMurdo, Ottawa, and Mt. Washington. All data showed annual variation. The patterns and degree of variation obtained in northern and southern hemisphere were similar. The summation dial representation of the annual variation and semi-annual variation of cosmic ray was obtained. The inversion of annual variation in 1958 - 1959 and 1968 - 1969 corresponded to the inversion of polarity of solar pole magnetic field. The semi-annual variation showed a complex behavior. The helio-latitudial distribution of cosmic ray intensity was obtained. The asymmetric distribution in relation to the solar equator was observed in the annual variation. The northward gradient of density in 1955 - 1958 and southward gradient in 1959 - 1968 were seen. (Kato, T.)

  13. Cosmic ray intensity in the past

    International Nuclear Information System (INIS)

    Dergachev, V.A.

    1977-01-01

    Variations of cosmic rays have been investigated according to the data on the content of radiocarbon in the Earth atmosphere, on the solar activity and on the geomagnetic field. The results of spectral analysis of the data on radiocarbon (1688-1951 time interval) and the data on the numbers of sunspots have been compared. As a result of spectral analysis it has been established that the two main peaks coincide in periods (approximately 11 and approximately 80 years) and differ in amplitudes. The 11-year periods are the main periods for the solar activity, and the 80-year periods for the radiocarbon concentration. To elucidate the role of the geomagnetic field in the cosmic ray variations considered are extermal changes in the magnetic field and variations in the radiocarbon content for four time intervals: 0-500 years, 750-2200 years, 2200-4500 years and 4500-6800 years form the present. The following cycles have been revealed in the time spectra of radiocarbon; approximately 600, approximately 360, approximately 80, approximately 36 years, their relative amplitude decreasing with the period. The absence of short-range solar syscle is typical for the geomagnetic field intensity

  14. 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.

  15. Tracking performance with cosmic rays in CMS

    International Nuclear Information System (INIS)

    Cerati, G.B.

    2009-01-01

    The CMS Tracker is the biggest all-silicon detector in the world and is designed to be extremely efficient and accurate even in a very hostile environment such as the one close to the CMS collision point. It consists of an inner pixel detector, made of three barrel layers (48M pixels) and four forward disks (16M pixels), and an outer micro-strip detector, divided in two barrel sub-detectors, TIB and TOB, and two endcap sub-detectors, TID and TEC, for a total of 9.6M strips. The commissioning of the CMS Tracker detector has been initially carried out at the Tracker Integration Facility at CERN (TIF), where cosmic ray data were collected for the strip detector only, and is still ongoing at the CMS site (LHC Point 5). Here the Strip and Pixel detectors have been installed in the experiment and are taking part to the cosmic global-runs. After an overview of the tracking algorithms for cosmic-ray data reconstruction, the resulting tracking performance on cosmic data both at TIF and at P5 are presented. The excellent performance proves that the CMS Tracker is ready for the first collisions foreseen for 2009.

  16. Cosmic rays and new accelerator experiments

    International Nuclear Information System (INIS)

    Muraki, Y.

    The cross-section of sigma(anti-D,D) increases with energy. The heavy vector boson production cross-section deviates from the naive law 1/M 3 F(s/M 2 ) at very high energy. Comparison with dsigma/dP(T)/(had) and Drell-Yan cross-section dsigma/(dM/2)/(d-y) at very high energy will provide evidence about the existence of the colour quantum number. Centauro will soon be checked by a cosmic-ray experiment. The detail dynamics of such a hadron rich event will be extensively studied at anti-pp colliders. The investigation of the Feynman scaling at the anti-pp collider for hadrons brings a very important knowledge on astrophysics. The 2μ, 3μ, 4μ and multi muon bundle at the anti-pp colliders is extremely interesting. A cosmic ray muon bundle event suggests the successive decay of a anti-BB pair. The total cross-section for (anti-BB) is estimated as 500μb at 150 TeV

  17. 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

  18. Key scientific problems from Cosmic Ray History

    Science.gov (United States)

    Lev, Dorman

    2016-07-01

    Recently was published the monograph "Cosmic Ray History" by Lev Dorman and Irina Dorman (Nova Publishers, New York). What learn us and what key scientific problems formulated the Cosmic Ray History? 1. As many great discoveries, the phenomenon of cosmic rays was discovered accidentally, during investigations that sought to answer another question: what are sources of air ionization? This problem became interesting for science about 230 years ago in the end of the 18th century, when physics met with a problem of leakage of electrical charge from very good isolated bodies. 2. At the beginning of the 20th century, in connection with the discovery of natural radioactivity, it became apparent that this problem is mainly solved: it was widely accepted that the main source of the air ionization were α, b, and γ - radiations from radioactive substances in the ground (γ-radiation was considered as the most important cause because α- and b-radiations are rapidly absorbed in the air). 3. The general accepted wrong opinion on the ground radioactivity as main source of air ionization, stopped German meteorologist Franz Linke to made correct conclusion on the basis of correct measurements. In fact, he made 12 balloon flights in 1900-1903 during his PhD studies at Berlin University, carrying an electroscope to a height of 5500 m. The PhD Thesis was not published, but in Thesis he concludes: "Were one to compare the presented values with those on ground, one must say that at 1000 m altitude the ionization is smaller than on the ground, between 1 and 3 km the same amount, and above it is larger with values increasing up to a factor of 4 (at 5500 m). The uncertainties in the observations only allow the conclusion that the reason for the ionization has to be found first in the Earth." Nobody later quoted Franz Linke and although he had made the right measurements, he had reached the wrong conclusions, and the discovery of CR became only later on about 10 years. 4. Victor Hess, a

  19. 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)

  20. 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)

  1. Studying High pT muons in Cosmic-Ray Air Showers

    International Nuclear Information System (INIS)

    Klein, Spencer R.

    2006-01-01

    Most cosmic-ray air shower arrays have focused on detecting electromagnetic shower particles and low energy muons. A few groups (most notably MACRO + EASTOP and SPASE + AMANDA) have studied the high energy muon component of showers. However, these experiments had small solid angles, and did not study muons far from the core. The IceTop + IceCube combination, with its 1 km 2 muon detection area can study muons far from the shower core. IceCube can measure their energy loss (dE/dx), and hence their energy. With the energy, and the known distribution of production heights, the transverse momentum (p T ) spectrum of high p T muons can be determined. The production of the semuons is calculable in perturbative QCD, so the measured muon spectra can be used to probe the composition of incident cosmic-rays

  2. Results of cosmic ray intensity measurements by the ''Luna-19'' space probe

    International Nuclear Information System (INIS)

    Chuchkov, E.A.; Lyubimov, G.P.; Myagchenkova, O.G.; Novichkova, A.D.; Pereslegina, N.V.; Kontor, N.N.; Nikolaev, A.G.

    1975-01-01

    Results are reviewed of measurements of low energy cosmic-ray characteristics obtained by means of the equipment installed on the ''Luna-19'' space station over the period from 28 November, 1971 to August 20, 1972. Proton fluxes with the energy of 1-5, 5-10, 10-40 MeV were mainly detected. A brief analysis both of individual events in cosmic rays and the general variation of intensity over the period from 1971 to 1972 is presented. Solar and geophysical data are used for the analysis. It is demonstrated that the period of the ''Luna-19'' operation corresponded to the secondary (anomalous) maximum on the decay of the solar activity in the 20th cycle. Assumptions concerning the nature of this maximum are formulated

  3. Low-energy neutron measurements in an iron calorimeter structure irradiated by 200 GeV/c hadrons

    Energy Technology Data Exchange (ETDEWEB)

    Russ, J S [Carnegie-Mellon University, Pittsburgh, PA (United States); Stevenson, G R; Fasso, A; Nielsen, M C [CERN, Geneva (Switzerland); Furetta, C; Rancoita, P G; Vismara, I [INFN, Milan (Italy)

    1989-04-21

    Of serious concern in the design of detectors for the new high-luminosity hadron-hadron colliders are the radiation damage effects on silicon and other detectors of low-energy neutrons produced by spallation evaporation or fission processes. Because of the lack of experimental information on the number of neutrons with energies between 0.1 and 10 MeV in the cascades originating from high-energy hadrons, an experiment was carried out using activation detector techniques to measure the neutron fluence in a cascade initiated by 200 GeV hadrons in acalorimeter-like iron structure. It was found that at the maximum of the cascade one produces approximately 3 neutrons per GeV of incident energy: some 70% of these are of energies between 0.1 and 5 MeV, the remainder are fairly uniformly distributed in energy between 5 and several hundred MeV. The number of albedo neutrons leaving the front face of the calorimeter structure was about 0.3 neutrons per GeV of incident energy with in energy distribution similar to those at cascade maximum These data confirm that neutron-induced damage will he of concern in the design of detectors for the new colliders and that further measurements and calculations are necessary for a correct assessment of this damage. (author)

  4. Analytical Model for Estimating Terrestrial Cosmic Ray Fluxes Nearly Anytime and Anywhere in the World: Extension of PARMA/EXPACS.

    Directory of Open Access Journals (Sweden)

    Tatsuhiko Sato

    Full Text Available By extending our previously established model, here we present a new model called "PHITS-based Analytical Radiation Model in the Atmosphere (PARMA version 3.0," which can instantaneously estimate terrestrial cosmic ray fluxes of neutrons, protons, ions with charge up to 28 (Ni, muons, electrons, positrons, and photons nearly anytime and anywhere in the Earth's atmosphere. The model comprises numerous analytical functions with parameters whose numerical values were fitted to reproduce the results of the extensive air shower (EAS simulation performed by Particle and Heavy Ion Transport code System (PHITS. The accuracy of the EAS simulation was well verified using various experimental data, while that of PARMA3.0 was confirmed by the high R2 values of the fit. The models to be used for estimating radiation doses due to cosmic ray exposure, cosmic ray induced ionization rates, and count rates of neutron monitors were validated by investigating their capability to reproduce those quantities measured under various conditions. PARMA3.0 is available freely and is easy to use, as implemented in an open-access software program EXcel-based Program for Calculating Atmospheric Cosmic ray Spectrum (EXPACS. Because of these features, the new version of PARMA/EXPACS can be an important tool in various research fields such as geosciences, cosmic ray physics, and radiation research.

  5. Detection of fission signatures induced by a low-energy neutron source

    International Nuclear Information System (INIS)

    Ocherashvili, A.; Becka, A.; Mayorovb, V.; Roesgen, E.; Crochemoreb, J.-M.; Mosconi, M.; Pedersen, B.; Heger, C.

    2015-01-01

    We present a method for the detection of special nuclear materials (SNM) in shielded containers which is both sensitive and applicable under field conditions. The method uses an external pulsed neutron source to induce fission in SNM and subsequent detection of the fast prompt fission neutrons. The detectors surrounding the container under investigation are liquid scintillation detectors able to distinguish gamma rays from fast neutrons by means of the pulse shape discrimination method (PSD). One advantage of these detectors, besides the ability for PSD analysis, is that the analogue signal from a detection event is of very short duration (typically few tens of nanoseconds). This allows the use of very short coincidence gates for the detection of the prompt fission neutrons in multiple detectors while benefiting from a low accidental (background) coincidence rate yielding a low detection limit. Another principle advantage of this method derives from the fact that the external neutron source is pulsed. By proper time gating the interrogation can be conducted by epithermal and thermal source neutrons only. These source neutrons do not appear in the fast neutron signal following the PSD analysis thus providing a fundamental method for separating the interrogating source neutrons from the sample response in form of fast fission neutrons. The paper describes laboratory tests with a configuration of eight detectors in the Pulsed Neutron Interrogation Test Assembly (PUNITA). The sensitivity of the coincidence signal to fissile mass is investigated for different sample configurations and interrogation regimes.

  6. 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

  7. 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

  8. Irradiated ISM : Discriminating between cosmic rays and X-rays

    NARCIS (Netherlands)

    Meijerink, R.; Spaans, M.; Israel, F. P.

    2006-01-01

    The interstellar medium ( ISM) at the centers of active galaxies is exposed to a combination of cosmic-ray, far-ultraviolet (FUV), and X-ray radiation. We apply photodissociation region (PDR) models to this ISM with both "normal" and highly elevated (5 x 10(-15) s(-1)) cosmic- ray (CR) rates and

  9. Using the information on cosmic rays to predict influenza epidemics

    International Nuclear Information System (INIS)

    Yu, Z.D.

    1985-01-01

    A correlation between the incidence of influenza pandemics and increased cosmic ray activity is made. A correlation is also made between the occurrence of these pandemics and the appearance of bright novae, e.g., Nova Eta Car. Four indices based on increased cosmic ray activity and novae are proposed to predict future influenza pandemics and viral antigenic shifts

  10. 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 ...

  11. Modulation of Cosmic Ray Precipitation Related to Climate

    Science.gov (United States)

    Feynman, J.; Ruzmaikin, A.

    1998-01-01

    High energy cosmic rays may influence the formation of clouds, and thus can have an impact on weather and climate. Cosmic rays in the solar wind are incident on the magnetosphere boundary and are then transmitted through the magnetosphere and atmosphere to reach the upper troposphere.

  12. Balloon test project: Cosmic Ray Antimatter Calorimeter (CRAC)

    Science.gov (United States)

    Christy, J. C.; Dhenain, G.; Goret, P.; Jorand, J.; Masse, P.; Mestreau, P.; Petrou, N.; Robin, A.

    1984-01-01

    Cosmic ray observations from balloon flights are discussed. The cosmic ray antimatter calorimeter (CRAC) experiment attempts to measure the flux of antimatter in the 200-600 Mev/m energy range and the isotopes of light elements between 600 and 1,000 Mev/m.

  13. 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

  14. A preliminary investigation of the EBT2 radiochromic films response to low energy fast neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Aydarous, Abdulkadir, E-mail: Aydarous@gmail.com [Physics Department, Faculty of Science, Taif University, Al-Hawiah, Taif, PO Box 888 (Saudi Arabia); Faculty of Energy Systems and Nuclear Science, University of Ontario Institute of Technology, 2000 Simcoe St North, Oshawa, ON, L1H 7K4 (Canada); Aslam [Faculty of Energy Systems and Nuclear Science, University of Ontario Institute of Technology, 2000 Simcoe St North, Oshawa, ON, L1H 7K4 (Canada); Waker, Anthony [Faculty of Energy Systems and Nuclear Science, University of Ontario Institute of Technology, 2000 Simcoe St North, Oshawa, ON, L1H 7K4 (Canada); Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, ON, L8S 4M1 (Canada)

    2012-07-15

    EBT2 radiochromic films were used to study the relative dose distribution of the neutron field. The correlation between the beam current and the optical density showed good linear dependence with a correlation coefficient exceeding 98%. At any given beam energy, neutron dose rates can be changed by a factor of 40 without changing the neutron spectrum. This result is consistent with what was found by the Tissue Equivalent Proportional Counter measurements. The uniformity of the neutron field was inspected by the optical density profile of the exposed film. - Highlights: Black-Right-Pointing-Pointer Developing a 2D image for neutron field. Black-Right-Pointing-Pointer Investigation of EBT2 sensitivity to neutrons. Black-Right-Pointing-Pointer Studying the effect of irradiation parameters (beam energy and beam current) to the measured optical density.

  15. Precise calculations in simulations of the interaction of low energy neutrons with nano-dispersed media

    International Nuclear Information System (INIS)

    Artem’ev, V. A.; Nezvanov, A. Yu.; Nesvizhevsky, V. V.

    2016-01-01

    We discuss properties of the interaction of slow neutrons with nano-dispersed media and their application for neutron reflectors. In order to increase the accuracy of model simulation of the interaction of neutrons with nanopowders, we perform precise quantum mechanical calculation of potential scattering of neutrons on single nanoparticles using the method of phase functions. We compare results of precise calculations with those performed within first Born approximation for nanodiamonds with the radius of 2–5 nm and for neutron energies 3 × 10 -7 –10 -3 eV. Born approximation overestimates the probability of scattering to large angles, while the accuracy of evaluation of integral characteristics (cross sections, albedo) is acceptable. Using Monte-Carlo method, we calculate albedo of neutrons from different layers of piled up diamond nanopowder

  16. Precise calculations in simulations of the interaction of low energy neutrons with nano-dispersed media

    Science.gov (United States)

    Artem'ev, V. A.; Nezvanov, A. Yu.; Nesvizhevsky, V. V.

    2016-01-01

    We discuss properties of the interaction of slow neutrons with nano-dispersed media and their application for neutron reflectors. In order to increase the accuracy of model simulation of the interaction of neutrons with nanopowders, we perform precise quantum mechanical calculation of potential scattering of neutrons on single nanoparticles using the method of phase functions. We compare results of precise calculations with those performed within first Born approximation for nanodiamonds with the radius of 2-5 nm and for neutron energies 3 × 10-7-10-3 eV. Born approximation overestimates the probability of scattering to large angles, while the accuracy of evaluation of integral characteristics (cross sections, albedo) is acceptable. Using Monte-Carlo method, we calculate albedo of neutrons from different layers of piled up diamond nanopowder.

  17. Test of parity and time reversal invariance with low energy polarized neutrons

    International Nuclear Information System (INIS)

    Masaike, Akira

    1996-01-01

    Measurements of helicity asymmetries in slow neutron reactions on nuclei have been performed by transmission and capture γ-ray detection. Large enhancements of parity-violation effects have been observed on p-wave resonances of various medium and heavy nuclei. The weak matrix elements in hadron reactions have been deduced from these experimental results. Neutron spin precession near the p-wave resonance has been measured. In recent years violation of time reversal invariance is being searched for in the neutron reactions in which large enhancements of the parity violation effects have been observed. The measurement of the term σ n ·(k n x I) in a neutron reaction using polarized neutrons and a polarized target is an example of the test of T-violation. Polarizations of the neutron and lanthanum nucleus for these experiments are also presented. (author)

  18. Precise calculations in simulations of the interaction of low energy neutrons with nano-dispersed media

    Energy Technology Data Exchange (ETDEWEB)

    Artem’ev, V. A., E-mail: niitm@inbox.ru [Research Institute of Materials Technology (Russian Federation); Nezvanov, A. Yu. [Moscow State Industrial University (Russian Federation); Nesvizhevsky, V. V. [Institut Max von Laue—Paul Langevin (France)

    2016-01-15

    We discuss properties of the interaction of slow neutrons with nano-dispersed media and their application for neutron reflectors. In order to increase the accuracy of model simulation of the interaction of neutrons with nanopowders, we perform precise quantum mechanical calculation of potential scattering of neutrons on single nanoparticles using the method of phase functions. We compare results of precise calculations with those performed within first Born approximation for nanodiamonds with the radius of 2–5 nm and for neutron energies 3 × 10{sup -7}–10{sup -3} eV. Born approximation overestimates the probability of scattering to large angles, while the accuracy of evaluation of integral characteristics (cross sections, albedo) is acceptable. Using Monte-Carlo method, we calculate albedo of neutrons from different layers of piled up diamond nanopowder.

  19. Progress in high-energy cosmic ray physics

    Science.gov (United States)

    Mollerach, S.; Roulet, E.

    2018-01-01

    We review some of the recent progress in our knowledge about high-energy cosmic rays, with an emphasis on the interpretation of the different observational results. We discuss the effects that are relevant to shape the cosmic ray spectrum and the explanations proposed to account for its features and for the observed changes in composition. The physics of air-showers is summarized and we also present the results obtained on the proton-air cross section and on the muon content of the showers. We discuss the cosmic ray propagation through magnetic fields, the effects of diffusion and of magnetic lensing, the cosmic ray interactions with background radiation fields and the production of secondary neutrinos and photons. We also consider the cosmic ray anisotropies, both at large and small angular scales, presenting the results obtained from the TeV up to the highest energies and discuss the models proposed to explain their origin.

  20. Cosmic Rays in Magnetospheres of the Earth and other Planets

    CERN Document Server

    Dorman, Lev

    2009-01-01

    This monograph describes the behaviour of cosmic rays in the magnetosphere of the Earth and of some other planets. Recently this has become an important topic both theoretically, because it is closely connected with the physics of the Earth’s magnetosphere, and practically, since cosmic rays determine a significant part of space weather effects on satellites and aircraft. The book contains eight chapters, dealing with – The history of the discovery of geomagnetic effects caused by cosmic rays and their importance for the determination of the nature of cosmic rays or gamma rays – The first explanations of geomagnetic effects within the framework of the dipole approximation of the Earth’s magnetic field – Trajectory computations of cutoff rigidities, transmittance functions, asymptotic directions, and acceptance cones in the real geomagnetic field taking into account higher harmonics – Cosmic ray latitude-longitude surveys on ships, trains, tracks, planes, balloons and satellites for determining the...

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. Ultrahigh-energy cosmic-ray spectrum

    International Nuclear Information System (INIS)

    Hill, C.T.; Schramm, D.N.

    1985-01-01

    We analyze the evolution of the ultrahigh-energy cosmic-ray spectrum upon traversing the 2.7 0 K microwave background with respect to pion photoproduction, pair-production reactions, and cosmological effects. Our approach employs exact transport equations which manifestly conserve nucleon number and embody the laboratory details of these reactions. A spectrum enhancement appears around 6 x 10 19 eV due to the ''pile-up'' of energy-degraded nucleons, and a ''dip'' occurs around 10 19 eV due to combined effects. Both of these features appear in the observational spectrum. We analyze the resulting neutrino spectrum and the effects of cosmological source distributions. We present a complete model of the ultrahigh-energy spectrum and anisotropy in reasonable agreement with observation and which predicts an observable electron-neutrino spectrum

  7. Early Cosmic Ray Research with Balloons

    Energy Technology Data Exchange (ETDEWEB)

    Walter, Michael, E-mail: michael.walter@desy.de

    2013-06-15

    The discovery of cosmic rays by Victor Hess during a balloon flight in 1912 at an altitude of 5350 m would not have been possible without the more than one hundred years development of scientific ballooning. The discovery of hot air and hydrogen balloons and their first flights in Europe is shortly described. Scientific ballooning was mainly connected with activities of meteorologists. It was also the geologist and meteorologist Franz Linke, who probably observed first indications of a penetrating radiation whose intensity seemed to increase with the altitude. Karl Bergwitz and Albert Gockel were the first physicists studying the penetrating radiation during balloon flights. The main part of the article deals with the discovery of the extraterrestrial radiation by V. Hess and the confirmation by Werner Kolhörster.

  8. Early Cosmic Ray Research with Balloons

    Science.gov (United States)

    Walter, Michael

    2013-06-01

    The discovery of cosmic rays by Victor Hess during a balloon flight in 1912 at an altitude of 5350 m would not have been possible without the more than one hundred years development of scientific ballooning. The discovery of hot air and hydrogen balloons and their first flights in Europe is shortly described. Scientific ballooning was mainly connected with activities of meteorologists. It was also the geologist and meteorologist Franz Linke, who probably observed first indications of a penetrating radiation whose intensity seemed to increase with the altitude. Karl Bergwitz and Albert Gockel were the first physicists studying the penetrating radiation during balloon flights. The main part of the article deals with the discovery of the extraterrestrial radiation by V. Hess and the confirmation by Werner Kolhörster.

  9. Early Cosmic Ray Research with Balloons

    International Nuclear Information System (INIS)

    Walter, Michael

    2013-01-01

    The discovery of cosmic rays by Victor Hess during a balloon flight in 1912 at an altitude of 5350 m would not have been possible without the more than one hundred years development of scientific ballooning. The discovery of hot air and hydrogen balloons and their first flights in Europe is shortly described. Scientific ballooning was mainly connected with activities of meteorologists. It was also the geologist and meteorologist Franz Linke, who probably observed first indications of a penetrating radiation whose intensity seemed to increase with the altitude. Karl Bergwitz and Albert Gockel were the first physicists studying the penetrating radiation during balloon flights. The main part of the article deals with the discovery of the extraterrestrial radiation by V. Hess and the confirmation by Werner Kolhörster

  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. Directional clustering in highest energy cosmic rays

    International Nuclear Information System (INIS)

    Goldberg, Haim; Weiler, Thomas J.

    2001-01-01

    An unexpected degree of small-scale clustering is observed in highest-energy cosmic ray events. Some directional clustering can be expected due to purely statistical fluctuations for sources distributed randomly in the sky. This creates a background for events originating in clustered sources. We derive analytic formulas to estimate the probability of random cluster configurations, and use these formulas to study the strong potential of the HiRes, Auger, Telescope Array and EUSO-OWL-AirWatch facilities for deciding whether any observed clustering is most likely due to nonrandom sources. For a detailed comparison to data, our analytical approach cannot compete with Monte Carlo simulations, including experimental systematics. However, our derived formulas do offer two advantages: (i) easy assessment of the significance of any observed clustering, and most importantly, (ii) an explicit dependence of cluster probabilities on the chosen angular bin size

  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. Low energy 7Li(p,n)7Be neutron source (CANUTRON)

    International Nuclear Information System (INIS)

    Lone, M.A.; Ross, A.M.; Fraser, J.S.; Schriber, S.O.; Kushneriuk, S.A.; Selander, W.N.

    1982-04-01

    Characteristics of a neutron source based on the 7 Li(p,n) reaction at 2.5 MeV are investigated. It is shosn that with a 10-50 mA beam current this reaction provides a useful source for neutron radiography and other industrial applications

  14. Low energy E0 transitions in odd-mass nuclei of the neutron deficient 180 < A < 200 region

    International Nuclear Information System (INIS)

    Zganjar, E.F.; Kortelahti, M.O.; Wood, J.L.; Papanicolopulos, C.D.

    1987-01-01

    The region of neutron-deficient nuclei near Z = 82 and N = 104 provides the most extensive example of low-energy shape coexistence anywhere on the mass surface. It is shown that E0 and E0 admixed transitions may be used as a fingerprint to identify shape coexistence in odd-mass nuclei. It is also shown that all the known cases of low energy E0 and E0 admixed transitions in odd-mass nuclei occur where equally low-lying O + states occur in neighboring even-even nuclei. A discussion of these and other relevant data as well as suggestions for new studies which may help to clarify and, more importantly, quantify the connection between E0 transitions and shape coexistence are presented. 60 refs., 7 figs., 4 tabs

  15. A {mu}TPC detector for the characterization of low energy neutron fields

    Energy Technology Data Exchange (ETDEWEB)

    Golabek, C., E-mail: cedric.golabek@irsn.fr [Laboratoire de Metrologie et de Dosimetrie des Neutrons, IRSN Cadarache, 13115 Saint-Paul-Lez-Durance (France); Billard, J. [Laboratoire de Physique Subatomique et de Cosmologie, Universite Joseph Fourier Grenoble 1, CNRS/IN2P3, Institut Polytechnique de Grenoble, 53 rue des Martyrs, 38026 Grenoble (France); Allaoua, A. [Laboratoire de Metrologie et de Dosimetrie des Neutrons, IRSN Cadarache, 13115 Saint-Paul-Lez-Durance (France); Bosson, G.; Bourrion, O.; Grignon, C.; Guillaudin, O. [Laboratoire de Physique Subatomique et de Cosmologie, Universite Joseph Fourier Grenoble 1, CNRS/IN2P3, Institut Polytechnique de Grenoble, 53 rue des Martyrs, 38026 Grenoble (France); Lebreton, L., E-mail: lena.lebreton@irsn.fr [Laboratoire de Metrologie et de Dosimetrie des Neutrons, IRSN Cadarache, 13115 Saint-Paul-Lez-Durance (France); Mayet, F. [Laboratoire de Physique Subatomique et de Cosmologie, Universite Joseph Fourier Grenoble 1, CNRS/IN2P3, Institut Polytechnique de Grenoble, 53 rue des Martyrs, 38026 Grenoble (France); Petit, M. [Laboratoire de Metrologie et de Dosimetrie des Neutrons, IRSN Cadarache, 13115 Saint-Paul-Lez-Durance (France); Richer, J.-P.; Santos, D. [Laboratoire de Physique Subatomique et de Cosmologie, Universite Joseph Fourier Grenoble 1, CNRS/IN2P3, Institut Polytechnique de Grenoble, 53 rue des Martyrs, 38026 Grenoble (France)

    2012-06-21

    The AMANDE facility produces monoenergetic neutron fields from 2 keV to 20 MeV for metrological purposes. To be considered as a reference facility, fluence and energy distributions of neutron fields have to be determined by primary measurement standards. For this purpose, a micro Time Projection Chamber is being developed to be dedicated to measure neutron fields with energy ranging from 8 keV up to 1 MeV. In this work we present simulations showing that such a detector, which allows the measurement of the ionization energy and the 3D reconstruction of the recoil nucleus, provides the determination of neutron energy and fluence of these neutron fields.

  16. Penetration of cosmic ray muons into the Earth

    International Nuclear Information System (INIS)

    Uretsky, J.L.

    1997-01-01

    I present a new analytic solution to the integro-differential equation that describes the underground propagation of cosmic ray muons. The exact solution is given in the form of an infinite series in inverse powers of the muon energy. Convergence is proved for sufficiently high energies. The series is shown to be summable in closed form, in certain approximations. The closed forms provides analytic continuations to low energies of the series solution. One approximation resembles a well-known solution that ignores discrete energy loss, but this approximation introduces additional constants. I apply the approximate solution using an expression for the surface muon flux, derived from the primary flux, as a boundary condition. The result predicts the underground muon vertical intensity over seven orders of magnitude (10 km depth), compares favorably with published Monte Carlo calculations, and can be performed in seconds on a personal computer. As an application, the same approximation predicts the ''catastrophic'' energy-loss event rate at Soudan II. (orig.)

  17. Observational constraints on the possible existence of cosmological cosmic rays

    International Nuclear Information System (INIS)

    Montmerle, T.

    1977-01-01

    The possibility that cosmological cosmic rays (''CCR'': protons and α particles) may have existed in the post recombination era of the early universe (z approximately 100) is examined. In this context, the CCR interact with the ambient gaseous medium. High energy collisions ( (>=) 1 GeV/n ) give rise to diffuse background γ-rays via π deg decay, and low energy collisions (approximately 10-100 MeV/n) give rise to light nuclei: 6 Li, 7 Li and 7 Be (via the α + α sion and ionization losses into account, a system of coupled time-dependent transport equations is solved in the case of a CCR burst. The 1-100 MeV γ-ray background spectrum and the light element abundances are then taken as observational constraints on the CCR hypothesis. It is found that, in this framework, it is possible to account simultaneously for the γ-ray background spectrum and for the otherwise unexplained 7 Li/H ratio, but there are some difficulties with the 7 Li/ 6 Li ratio. To avoid these, it is possible, because of the spread in the γ-ray data, to lower the CCR flux, so that the CCR hypothesis cannot be ruled out on this basis at present. (author)

  18. Low energy neutrons from a sup 2 sup 3 sup 9 PuBe isotopic neutron source inserting in moderating media

    CERN Document Server

    Vega, H R

    2002-01-01

    Several neutron applications share a common problem: the neutron source design. In this work MCNP computer code has been used to design a moderated sup 2 sup 3 sup 9 PuBe neutron source to produce low energy neutrons. The design involves the source located at the center of a spherical moderator. Moderator media studied were light water, heavy water and a heterogeneous combination of light water and heavy water. Similar moderating features were found between the 24.5 cm-radius container filled with heavy water (23.0-cm-thick) and that made with light water (3.5-cm-thick) plus heavy water (19.5-cm-thick). A sup 2 sup 3 sup 9 PuBe neutron source inserted in this moderator produces, at 27 cm, a neutron fluence of 1.8 x 10 sup - sup 4 n-cm sup - sup 2 per source neutron, with an average neutron energy of 0.34 MeV, where 47.8 % have an energy <= 0.4 eV. A further study of this moderator was carried out using a reflector medium made of graphite. Thus, 15-cm-thickness reflector improves the neutron field producing...

  19. Two-neutron “halo” from the low-energy limit of neutron–neutron interaction: Applications to drip-line nuclei 22C and 24O

    Directory of Open Access Journals (Sweden)

    Toshio Suzuki

    2016-02-01

    Full Text Available The formation of two-neutron “halo”, a low-density far-extended surface of weakly-bound two neutrons, is described using the neutron–neutron (nn interaction fixed at the low-energy nn scattering limit. This method is tested for loosely-bound two neutrons in 24O, where a good agreement with experimental data is found. It is applied to halo neutrons in 22C in two ways: with the 20C core being closed or correlated (due to excitations from the closed core. This nn interaction is shown to be strong enough to produce a two-neutron halo in both cases, locating 22C on the drip line, while 21C remains unbound. A unique relation between the two neutron separation energy, S2n, and the radius of neutron halo is presented. New predictions for S2n and the radius of neutron halo are given for 22C. The appearance of Efimov states is also discussed.

  20. The neutronic design and performance of the Indiana University Cyclotron Facility (IUCF) Low Energy Neutron Source (LENS)

    Science.gov (United States)

    Lavelle, Christopher M.

    Neutron scattering research is performed primarily at large-scale facilities. However, history has shown that smaller scale neutron scattering facilities can play a useful role in education and innovation while performing valuable materials research. This dissertation details the design and experimental validation of the LENS TMR as an example for a small scale accelerator driven neutron source. LENS achieves competitive long wavelength neutron intensities by employing a novel long pulse mode of operation, where the neutron production target is irradiated on a time scale comparable to the emission time of neutrons from the system. Monte Carlo methods have been employed to develop a design for optimal production of long wavelength neutrons from the 9Be(p,n) reaction at proton energies ranging from 7 to 13 MeV proton energy. The neutron spectrum was experimentally measured using time of flight, where it is found that the impact of the long pulse mode on energy resolution can be eliminated at sub-eV neutron energies if the emission time distribution of neutron from the system is known. The emission time distribution from the TMR system is measured using a time focussed crystal analyzer. Emission time of the fundamental cold neutron mode is found to be consistent with Monte Carlo results. The measured thermal neutron spectrum from the water reflector is found to be in agreement with Monte Carlo predictions if the scattering kernels employed are well established. It was found that the scattering kernels currently employed for cryogenic methane are inadequate for accurate prediction of the cold neutron intensity from the system. The TMR and neutronic modeling have been well characterized and the source design is flexible, such that it is possible for LENS to serve as an effective test bed for future work in neutronic development. Suggestions for improvements to the design that would allow increased neutron flux into the instruments are provided.

  1. An application of statistical adjustment of data to the energetic solar cosmic ray increase of August 7, 1972

    International Nuclear Information System (INIS)

    Komori, H.

    1975-01-01

    Data of five minute intervals of the neutron intensity from twelve cosmic ray stations were utilized for this application. Five source parameters; amplitude a, latitude lambdasub(s), longitude PHIsub(s), power law exponent γ in spectral representation and power law exponent n of angular spread have been determined by the least-square method of Deming. (orig./WBU) [de

  2. The measurement of tripartition alpha particle low energy spectrum in 235U fission induced by thermal neutrons

    International Nuclear Information System (INIS)

    El Hage Sleiman, F.

    1980-01-01

    The energy spectrum of the α particles emitted in the thermal neutron induced fission of 235 U was measured from 11.5 MeV down to 2 MeV using the parabola mass spectrometer Lohengrin at the ILL high flux reactor. A Monte Carlo program, that simulates the α particle motion to the spectrometer, has been developed. Numerical results of Monte Carlo calculations for differents values of parameter are reported. The overall energy spectrum is slightly asymmetric at low energy. The possible reasons for the existence of this asymmetry are discussed [fr

  3. THE TEMPERATURE EFFECT IN SECONDARY COSMIC RAYS (MUONS) OBSERVED AT THE GROUND: ANALYSIS OF THE GLOBAL MUON DETECTOR NETWORK DATA

    Energy Technology Data Exchange (ETDEWEB)

    De Mendonça, R. R. S.; Braga, C. R.; Echer, E.; Dal Lago, A.; Rockenbach, M.; Schuch, N. J. [Space Geophysics Division, National Institute for Space Research, São José dos Campos, SP, 12227-010 (Brazil); Munakata, K.; Kato, C. [Physics Department, Shinshu University, Matsumoto, Nagano, 390-8621 (Japan); Kuwabara, T. [Graduate School of Science, Chiba University, Chiba City, Chiba 263-8522 (Japan); Kozai, M. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (ISAS/JAXA), Sagamihara, Kanagawa 252-5210 (Japan); Al Jassar, H. K.; Sharma, M. M. [Physics Department, Kuwait University, Kuwait City, 13060 (Kuwait); Tokumaru, M. [Solar Terrestrial Environment Laboratory, Nagoya University, Nagoya, Aichi, 464-8601 (Japan); Duldig, M. L.; Humble, J. E. [School of Physical Sciences, University of Tasmania, Hobart, Tasmania, 7001 (Australia); Evenson, P. [Bartol Research Institute, Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); Sabbah, I. [Department of Natural Sciences, College of Health Sciences, Public Authority for Applied Education and Training, Kuwait City, 72853 (Kuwait)

    2016-10-20

    The analysis of cosmic ray intensity variation seen by muon detectors at Earth's surface can help us to understand astrophysical, solar, interplanetary and geomagnetic phenomena. However, before comparing cosmic ray intensity variations with extraterrestrial phenomena, it is necessary to take into account atmospheric effects such as the temperature effect. In this work, we analyzed this effect on the Global Muon Detector Network (GMDN), which is composed of four ground-based detectors, two in the northern hemisphere and two in the southern hemisphere. In general, we found a higher temperature influence on detectors located in the northern hemisphere. Besides that, we noticed that the seasonal temperature variation observed at the ground and at the altitude of maximum muon production are in antiphase for all GMDN locations (low-latitude regions). In this way, contrary to what is expected in high-latitude regions, the ground muon intensity decrease occurring during summertime would be related to both parts of the temperature effect (the negative and the positive). We analyzed several methods to describe the temperature effect on cosmic ray intensity. We found that the mass weighted method is the one that best reproduces the seasonal cosmic ray variation observed by the GMDN detectors and allows the highest correlation with long-term variation of the cosmic ray intensity seen by neutron monitors.

  4. THE TEMPERATURE EFFECT IN SECONDARY COSMIC RAYS (MUONS) OBSERVED AT THE GROUND: ANALYSIS OF THE GLOBAL MUON DETECTOR NETWORK DATA

    International Nuclear Information System (INIS)

    De Mendonça, R. R. S.; Braga, C. R.; Echer, E.; Dal Lago, A.; Rockenbach, M.; Schuch, N. J.; Munakata, K.; Kato, C.; Kuwabara, T.; Kozai, M.; Al Jassar, H. K.; Sharma, M. M.; Tokumaru, M.; Duldig, M. L.; Humble, J. E.; Evenson, P.; Sabbah, I.

    2016-01-01

    The analysis of cosmic ray intensity variation seen by muon detectors at Earth's surface can help us to understand astrophysical, solar, interplanetary and geomagnetic phenomena. However, before comparing cosmic ray intensity variations with extraterrestrial phenomena, it is necessary to take into account atmospheric effects such as the temperature effect. In this work, we analyzed this effect on the Global Muon Detector Network (GMDN), which is composed of four ground-based detectors, two in the northern hemisphere and two in the southern hemisphere. In general, we found a higher temperature influence on detectors located in the northern hemisphere. Besides that, we noticed that the seasonal temperature variation observed at the ground and at the altitude of maximum muon production are in antiphase for all GMDN locations (low-latitude regions). In this way, contrary to what is expected in high-latitude regions, the ground muon intensity decrease occurring during summertime would be related to both parts of the temperature effect (the negative and the positive). We analyzed several methods to describe the temperature effect on cosmic ray intensity. We found that the mass weighted method is the one that best reproduces the seasonal cosmic ray variation observed by the GMDN detectors and allows the highest correlation with long-term variation of the cosmic ray intensity seen by neutron monitors.

  5. Temperature Effect in Secondary Cosmic Rays (MUONS) Observed at the Ground: Analysis of the Global MUON Detector Network Data

    Science.gov (United States)

    de Mendonça, R. R. S.; Braga, C. R.; Echer, E.; Dal Lago, A.; Munakata, K.; Kuwabara, T.; Kozai, M.; Kato, C.; Rockenbach, M.; Schuch, N. J.; Jassar, H. K. Al; Sharma, M. M.; Tokumaru, M.; Duldig, M. L.; Humble, J. E.; Evenson, P.; Sabbah, I.

    2016-10-01

    The analysis of cosmic ray intensity variation seen by muon detectors at Earth's surface can help us to understand astrophysical, solar, interplanetary and geomagnetic phenomena. However, before comparing cosmic ray intensity variations with extraterrestrial phenomena, it is necessary to take into account atmospheric effects such as the temperature effect. In this work, we analyzed this effect on the Global Muon Detector Network (GMDN), which is composed of four ground-based detectors, two in the northern hemisphere and two in the southern hemisphere. In general, we found a higher temperature influence on detectors located in the northern hemisphere. Besides that, we noticed that the seasonal temperature variation observed at the ground and at the altitude of maximum muon production are in antiphase for all GMDN locations (low-latitude regions). In this way, contrary to what is expected in high-latitude regions, the ground muon intensity decrease occurring during summertime would be related to both parts of the temperature effect (the negative and the positive). We analyzed several methods to describe the temperature effect on cosmic ray intensity. We found that the mass weighted method is the one that best reproduces the seasonal cosmic ray variation observed by the GMDN detectors and allows the highest correlation with long-term variation of the cosmic ray intensity seen by neutron monitors.

  6. Some Principal Problems in Physics and Low-Energy Neutron Physics

    CERN Document Server

    Alexandrov, Yu A

    2004-01-01

    The first question deals with the charge neutron radius $^{1/2}$ connected with the value of neutron-electron scattering length $a_{ne}$ determined at low neutron energies. At present, the obtained accuracy allows us to speak not only about the value of $$ but also on the segmentation of $$ into Dirac and Foldy addenda. The sign of the Dirac addendum is connected directly with the fundamental Yukawa theory explaining the origin of nuclear forces. One of the popular experimental values of the Dirac addendum (from ${a}_{ne} = (-1.32 \\pm 0.03) \\cdot 10^{ - 16}$ cm) contradicts the Yukawa theory. The second question also concerns the subject of the structure of the neutron, namely its deformation. The notion of deformation (polarizability) of the nucleon in electromagnetic field was introduced in the mid-1950s. The reasons are given in favor of the opinion that the neutron polarizability was observed for the first time in neutron experiments as far back as 1957, i.\\,e. earlier than proton polarizability was detec...

  7. OBSERVATION OF COSMIC-RAY ANISOTROPY WITH THE ICETOP AIR SHOWER ARRAY

    Energy Technology Data Exchange (ETDEWEB)

    Aartsen, M. G. [School of Chemistry and Physics, University of Adelaide, Adelaide, SA 5005 Australia (Australia); Abbasi, R.; Ahlers, M.; Andeen, K.; Auffenberg, J.; Baker, M. [Department of Physics and Wisconsin IceCube Particle Astrophysics Center, University of Wisconsin, Madison, WI 53706 (United States); Abdou, Y. [Department of Physics and Astronomy, University of Gent, B-9000 Gent (Belgium); Ackermann, M. [DESY, D-15735 Zeuthen (Germany); Adams, J. [Department of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch (New Zealand); Aguilar, J. A. [Departement de physique nucleaire et corpusculaire, Universite de Geneve, CH-1211 Geneve (Switzerland); Altmann, D. [Institut fuer Physik, Humboldt-Universitaet zu Berlin, D-12489 Berlin (Germany); Bai, X. [Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); Barwick, S. W. [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Baum, V. [Institute of Physics, University of Mainz, Staudinger Weg 7, D-55099 Mainz (Germany); Bay, R. [Department of Physics, University of California, Berkeley, CA 94720 (United States); Beattie, K. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Beatty, J. J. [Department of Physics and Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, OH 43210 (United States); Bechet, S. [Science Faculty CP230, Universite Libre de Bruxelles, B-1050 Brussels (Belgium); Tjus, J. Becker [Fakultaet fuer Physik and Astronomie, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany); Becker, K.-H. [Department of Physics, University of Wuppertal, D-42119 Wuppertal (Germany); Collaboration: IceCube Collaboration; and others

    2013-03-01

    We report on the observation of anisotropy in the arrival direction distribution of cosmic rays at PeV energies. The analysis is based on data taken between 2009 and 2012 with the IceTop air shower array at the south pole. IceTop, an integral part of the IceCube detector, is sensitive to cosmic rays between 100 TeV and 1 EeV. With the current size of the IceTop data set, searches for anisotropy at the 10{sup -3} level can, for the first time, be extended to PeV energies. We divide the data set into two parts with median energies of 400 TeV and 2 PeV, respectively. In the low energy band, we observe a strong deficit with an angular size of about 30 Degree-Sign and an amplitude of (- 1.58 {+-} 0.46{sub stat} {+-} 0.52{sub sys}) Multiplication-Sign 10{sup -3} at a location consistent with previous observations of cosmic rays with the IceCube neutrino detector. The study of the high energy band shows that the anisotropy persists to PeV energies and increases in amplitude to (- 3.11 {+-} 0.38{sub stat} {+-} 0.96{sub sys}) Multiplication-Sign 10{sup -3}.

  8. 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.

  9. Solar tri-diurnal variation of cosmic rays in a wide range of rigidity

    Science.gov (United States)

    Mori, S.; Ueno, H.; Fujii, Z.; Morishita, I.; Nagashima, K.

    1985-01-01

    Solar tri-diurnal variations of cosmic rays have been analyzed in a wide range of rigidity, using data from neutron monitors, and the surface and underground muon telescopes for the period 1978-1983. The rigidity spectrum of the anisotropy in space is assumed to be of power-exponential type as (P/gamma P sub o) to the gamma exp (gamma-P/P sub o). By means of the best-fit method between the observed and the expected variations, it is obtained that the spectrum has a peak at P (=gamma P sub o) approx = 90 GV, where gamma=approx 3.0 and P sub o approx. 30 GV. The phase in space of the tri-diurnal variation is also obtained as 7.0 hr (15 hr and 23 hr LT), which is quite different from that of approx. 1 hr. arising from the axisymmetric distribution of cosmic rays with respect to the IMF.

  10. 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.

  11. The cosmic-ray shock structure problem for relativistic shocks

    Science.gov (United States)

    Webb, G. M.

    1985-01-01

    The time asymptotic behaviour of a relativistic (parallel) shock wave significantly modified by the diffusive acceleration of cosmic-rays is investigated by means of relativistic hydrodynamical equations for both the cosmic-rays and thermal gas. The form of the shock structure equation and the dispersion relation for both long and short wavelength waves in the system are obtained. The dependence of the shock acceleration efficiency on the upstream fluid spped, long wavelength Mach number and the ratio N = P sub co/cP sub co+P sub go)(Psub co and P sub go are the upstream cosmic-ray and thermal gas pressures respectively) are studied.

  12. The intergalactic propagation of ultrahigh energy cosmic ray nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Hooper, Dan; /Fermilab; Sarkar, Subir; /Oxford U., Theor. Phys.; Taylor, Andrew M.; /Oxford U.

    2006-08-01

    We investigate the propagation of ultra-high energy cosmic ray nuclei (A = 1-56) from cosmologically distant sources through the cosmic radiation backgrounds. Various models for the injected composition and spectrum and of the cosmic infrared background are studied using updated photodisintegration cross-sections. The observational data on the spectrum and the composition of ultra-high energy cosmic rays are jointly consistent with a model where all of the injected primary cosmic rays are iron nuclei (or a mixture of heavy and light nuclei).

  13. Measurements at LHC and their relevance for cosmic ray physics

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    Many LHC measurements are already used to improve hadronic interaction models used in cosmic ray analyses. This already had a positive effect on the model dependence of crucial data analyses. Some of the data and the model tuning is reviewed. However, the LHC still has a lot more potential to provide crucial information. Since the start of Run2 the highest accelerator beam energies are reached and no further increase can be expected for a long time. First data of Run2 are published and the fundamental performance of cosmic ray hadronic interaction models can be scrutinized. The relevance of LHC data in general for cosmic ray data analyses is demonstrated.

  14. Muon Production in Relativistic Cosmic-Ray Interactions

    OpenAIRE

    Klein, Spencer

    2009-01-01

    Cosmic-rays with energies up to $3\\times10^{20}$ 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 $\\sqrt{s_{nn}} = 700$ 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 de...

  15. Quasars as Sources of Ultrahigh-Energy Cosmic Rays

    International Nuclear Information System (INIS)

    Glushkov, A.V.

    2005-01-01

    The results are presented that were obtained by analyzing arrival directions for cosmic rays that the Yakutsk array for studying extensive air showers recorded between 1974 and 2002 in the energy region E 0 ≥5x10 17 eV for zenith angles in the region θ ≤60 deg. . It is shown that quasars for which the redshift lies in the region z≤2.5 can be sources of these cosmic rays. Ordered structures are observed in the disposition of quasars and in the cosmic-ray arrival directions. These structures can be associated in one way or another with the large-scale structure of the Universe

  16. 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.

  17. Feasibility study of a level gauge using cosmic-rays

    International Nuclear Information System (INIS)

    Matsuda, Hideharu; Fukaya, Mitsuharu; Minato, Susumu

    1989-01-01

    Cosmic-ray intensities were measured at the stairs in a subway station in Nagoya City, inside a tall concrete building and under a cylindrical water tank to examine the feasibility of a cosmic-ray level gauge using a scintillation counter. The measured results agreed quite well with theoretical calculations. The maximum distinguishable water depth was evaluated to be approximately the radius of the tank from the results of many systematic calculations. It was found from these results that the practical application of a cosmic-ray level gauge is feasible. (author)

  18. 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.

  19. Advanced detection techniques for educational experiments in cosmic ray physics

    International Nuclear Information System (INIS)

    Aiola, Salvatore; La-Rocca, Paola; Riggi, Francesco; Riggi, Simone

    2013-06-01

    In this paper we describe several detection techniques that can be employed to study cosmic ray properties and carry out training activities at high school and undergraduate level. Some of the proposed devices and instrumentation are inherited from professional research experiments, while others were especially developed and marketed for educational cosmic ray experiments. The educational impact of experiments in cosmic ray physics in high-school or undergraduate curricula will be exploited through various examples, going from simple experiments carried out with small Geiger counters or scintillation devices to more advanced detection instrumentation which can offer starting points for not trivial research work. (authors)

  20. Cosmic-ray antimatter - A primary origin hypothesis

    Science.gov (United States)

    Stecker, F. W.; Protheroe, R. J.; Kazanas, D.

    1983-01-01

    The present investigation is concerned with the possibility that the observed cosmic-ray protons are of primary extragalactic origin, taking into account the significance of the current antiproton data. Attention is given to questions regarding primary antiprotons, antihelium fluxes, and the propagation of extragalactic cosmic rays. It is concluded that the primary origin hypothesis should be considered as a serious alternative explanation for the cosmic-ray antiproton fluxes. Such extragalactic primary origin can be considered in the context of a baryon symmetric domain cosmology. The fluxes and propagation characteristics suggested are found to be in rough agreement with the present antiproton data.

  1. Response of CMS avalanche photo-diodes to low energy neutrons

    Science.gov (United States)

    Brown, R. M.; Deiters, K.; Ingram, Q.; Renker, D.

    2012-12-01

    The response of the Avalanche Photo-diodes (APDs) installed in the CMS detector at the LHC to neutrons from 241AmBe and 252Cf sources is reported. Signals in size equivalent to those of up to 106 photo-electrons with the nominal APD gain are observed. Measurements with an APD with the protective epoxy coating removed and with the source placed behind the APD show that there is an important response due to recoil protons from neutron interactions with the hydrogen in the epoxy, in addition to signals from neutron interactions with the silicon of the diode. The effective gain of these signals is much smaller than the diode's nominal gain.

  2. μ-TPC: a future standard instrument for low energy neutron field characterization

    International Nuclear Information System (INIS)

    Maire, D.; Lebreton, L.; Petit, M.; Billard, J.; Bourrion, O.; Bosson, G.; Guillaudin, O.; Lamblin, J.; Mayet, F.; Medard, J.; Muraz, J.F.; Richer, J.P.; Riffard, Q.; Santos, D.

    2013-06-01

    In order to measure energy of neutron fields, with energy ranging from 8 keV to 1 MeV, a new primary standard is being developed at the IRSN (Institute for Radioprotection and Nuclear Safety). This project, μ-TPC (Micro Time Projection Chamber), carried out in collaboration with the LPSC (Laboratoire de Physique Subatomique et de Cosmologie), is based on the nucleus recoil detector principle. The instrument will be presented with the associated method to measure the neutron energy. This article will emphasize the proton energy calibration procedure and energy measurements of a neutron field produced at 127 keV on the IRSN facility AMANDE. Finally the COMIMAC device, dedicated to the calibration, will be described. This original device, developed at the LPSC, is able to produce proton and electron beams with an accurate energy ranging from 1 keV to 50 keV. (authors)

  3. Model-dependent estimate on the connection between fast radio bursts and ultra high energy cosmic rays

    International Nuclear Information System (INIS)

    Li, Xiang; Zhou, Bei; He, Hao-Ning; Fan, Yi-Zhong; Wei, Da-Ming

    2014-01-01

    The existence of fast radio bursts (FRBs), a new type of extragalatic transient, has recently been established, and quite a few models have been proposed. In this work, we discuss the possible connection between the FRB sources and ultra high energy (>10 18 eV) cosmic rays. We show that in the blitzar model and the model of merging binary neutron stars, which includes the huge energy release of each FRB central engine together with the rather high rate of FRBs, the accelerated EeV cosmic rays may contribute significantly to the observed ones. In other FRB models, including, for example, the merger of double white dwarfs and the energetic magnetar radio flares, no significant EeV cosmic ray is expected. We also suggest that the mergers of double neutron stars, even if they are irrelevant to FRBs, may play a nonignorable role in producing EeV cosmic ray protons if supramassive neutron stars are formed in a sufficient fraction of mergers and the merger rate is ≳ 10 3 yr –1 Gpc –3 . Such a possibility will be unambiguously tested in the era of gravitational wave astronomy.

  4. Pulsed neutron generators based on plasma focus devices of low energy

    International Nuclear Information System (INIS)

    Silva, Patricio; Moreno, Jose; Soto, Leopoldo

    2003-01-01

    The plasma focus is a pulsed neutron source especially suited for applications because it reduces the danger of contamination of conventional isotopic radioactive sources. As first stage of a program to design a repetitive pulsed neutron generator for industrial applications we constructed two very small plasma focus operating at an energy level of the order of a) tens of joules (PF-50J, 160nF capacitor bank, 20-35 kV, 32-100J, ∼150ns first quarter of period) and b) hundred of joules (PF-400J, 880nF, 20-35kV, 176-539J, ∼300ns first quarter of period). In this article we present results related to design and construction of these small plasma foci (PF-50J and PF-400J). Neutron yield vs. deuterium. pressure has been obtained, a maximum emission of the order of 7x10 4 and 10 6 neutrons per shot has been measured in the PF-50J and PF-400J respectively (author)

  5. Theory Summary: Very High Energy Cosmic Rays

    Directory of Open Access Journals (Sweden)

    Sarkar Subir

    2013-06-01

    Full Text Available This is a summary of ISVHECRI 2012 from a theorist’s perspective. A hundred years after their discovery, there is renewed interest in very high energy cosmic raysand their interactions which can provide unique information on new physics well beyond the Standard Model if only we knew how to unambiguously decipher the experimental data. While the observational situation has improved dramatically on the past decade with regard to both improved statistics and better understood systematics, the long standing questions regarding the origin of cosmic rays remain only partially answered, while further questions have been raised by new data. A recent development discussed at this Symposium is the advent of forward physics data from several experiments at the LHC, which have broadly vindicated the air shower simulation Monte Carlos currently in use and reduced their uncertainties further. Nevertheless there is still a major extrapolation required to interpret the highest energy air showers observed which appear to be undergoing a puzzling change in their elemental composition, even casting doubt on whether the much vaunted GZK cutoff has indeedbeen observed. The situation is further compounded by the apparent disagreement between Auger and Telescope Array data. A crucial diagnostic will be provided by the detection of the accompanying ultra-high energy cosmic neutrinos — two intriguing events have recently been recorded by IceCube.

  6. Cosmic Ray Hit Detection with Homogenous Structures

    Science.gov (United States)

    Smirnov, O. M.

    Cosmic ray (CR) hits can affect a significant number of pixels both on long-exposure ground-based CCD observations and on the Space Telescope frames. Thus, methods of identifying the damaged pixels are an important part of the data preprocessing for practically any application. The paper presents an implementation of a CR hit detection algorithm based on a homogenous structure (also called cellular automata ), a concept originating in artificial intelligence and dicrete mathematics. Each pixel of the image is represented by a small automaton, which interacts with its neighbors and assumes a distinct state if it ``decides'' that a CR hit is present. On test data, the algorithm has shown a high detection rate (~0.7 ) and a low false alarm rate (frame. A homogenous structure is extremely trainable, which can be very important for processing large batches of data obtained under similar conditions. Training and optimizing issues are discussed, as well as possible other applications of this concept to image processing.

  7. 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

  8. 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.

  9. Applications of Cosmic Ray Muon Radiography

    Science.gov (United States)

    Guardincerri, E.; Durham, J. M.; Morris, C. L.; Rowe, C. A.; Poulson, D. C.; Bacon, J. D.; Plaud-Ramos, K.; Morley, D. J.

    2015-12-01

    The Dome of Santa Maria del Fiore, Florence Cathedral, was built between 1420 and 1436 by architect Filippo Brunelleschi and it is now cracking under its own weight. Engineering efforts are underway to model the dome's structure and reinforce it against further deterioration. According to some scholars, Brunelleschi might have built reinforcement structures into the dome itself; however, the only confirmed known subsurface reinforcement is a chain of iron and stone around the dome's base. Tomography with cosmic ray muons is a non-destructive imaging method that can be used to image the interior of the wall and therefore ascertain the layout and status of any iron substructure in the dome. We will show the results from a muon tomography measurement of iron hidden in a mockup of the dome's wall performed at Los Alamos National Lab in 2015. The sensitivity of this technique, and the status of this project will be also discussed. At last, we will show results on muon attenuation radiography of larger shallow targets.

  10. Solar induced long- and short-term variations of the cosmic ray intensity in the past, and predictions and opportunities for the future

    Science.gov (United States)

    McCracken, K. G.; McDonald, F. B.; Beer, J.

    2009-12-01

    The cosmogenic radionuclide data from the past 10,000 years, and the instrumental cosmic ray data since 1936 provide detailed information on the possible consequences of the present long and deep solar minimum. Furthermore, the cosmic ray transport equation has been used to estimate the strength of the interplanetary magnetic field (IMF) throughout the past 10,000 years. This paper presents a series of figures that document the behavior of both the cosmic radiation and the IMF at Earth in the past. In particular, the 11-year cycles in both quantities for the past 600 years are displayed; and estimates given of the cosmic ray spectrum at Earth for situations that history tells us may occur in the near future. Over the longer term, a minimum of the Hallstatt cycle (2200 yr periodicity) of solar activity occurred ~500 years ago and the Sun is now on a steadily rising plane of activity. The historic record shows that the cosmic ray intensity has decreased extremely rapidly after earlier prolonged deep minima and this suggests rapid and large changes in the heliospheric conditions that we may see replicated. The paper will also display data from the deep, isolated solar minimum of 1956 that exhibited unusual low energy cosmic ray fluxes, and a highly anomalous cosmic ray gradient in the inner heliosphere. Paleo-cosmic ray evidence will also be displayed of an episode of intense solar energetic particle (SEP) events in the interval of reduced solar activity, 1892-1900, that may possibly be repeated. If the present long, deep solar minimum is a precursor to a “Grand Minimum” such as the Dalton minimum, it will provide a much improved insight into the spectrum of the cosmic radiation in interstellar space, and to the cosmic ray modulation process in the heliosphere. With this in mind, the paper suggests key measurements, and speculates on experimental conditions that may be markedly different from those encountered in the instrumental era.

  11. 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.

  12. Modulation of cosmic rays on geomagnetically most quiet days

    Science.gov (United States)

    Agarwal Mishra, Rekha; Agarwal Mishra, Rekha; Mishra, Rajesh Kumar

    The aim of this work is to study the first three harmonics of cosmic ray intensity on geomagnetically quiet days over the period 1980-1990 for Deep River and Tokyo neutron monitoring stations. The amplitude of first harmonic remains high for Deep River having low cutoff rigidity as compared to Tokyo neutron monitor having high cutoff rigidity on quiet days.. The diurnal time of maximum significantly shifts to an earlier time as compared to the corotational/1800 Hr direction at both the stations 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 i.e. Deep River as compared to the high cut off rigidity station i.e. Tokyo on quiet days. The amplitude of semi/tri-diurnal anisotropy have a good positive correlation with solar wind velocity, while the others (i.e. amplitude and phase) have no significant correlation on quiet days for Deep River and Tokyo having different cutoff rigidity during 1980-1990. The solar wind velocity significantly remains in the range 350 to 425 km/s i.e. being nearly average on quiet days. The amplitude and direction of the anisotropy on quiet days are weakly dependent on high-speed solar wind streams for two neutron monitoring station of low and high cutoff rigidity threshold. The semi-diurnal amplitude has a significant anti-correlation, whereas the amplitude of third harmonic and direction of first harmonic has a good anti-correlation with IMF Bz and the product V x Bz on quiet days at Deep River station. However, the direction of first harmonic has a significant anti-correlation and the direction of second harmonic has a good anti-correlation with IMF Bz and the product V x Bz on quiet days at Tokyo station.

  13. 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

  14. 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.

  15. PAMELA: A Satellite Experiment for Antiparticles Measurement in Cosmic Rays

    Science.gov (United States)

    Bongi, M.; Adriani, O.; Ambriola, M.; Bakaldin, A.; Barbarino, G. C.; Basili, A.; Bazilevskaja, G.; Bellotti, R.; Bencardino, R.; Boezio, M.; Bogomolov, E. A.; Bonechi, L.; Bongiorno, L.; Bonvicini, V.; Boscherini, M.; Cafagna, F. S.; Campana, D.; Carlson, P.; Casolino, M.; Castellini, G.; Circella, M.; De Marzo, C. N.; De Pascale, M. P.; Furano, G.; Galper, A. M.; Giglietto, N.; Grigorjeva, A.; Koldashov, S. V.; Korotkov, M. G.; Krut'kov, S. Y.; Lund, J.; Lundquist, J.; Menicucci, A.; Menn, W.; Mikhailov, V. V.; Minori, M.; Mirizzi, N.; Mitchell, J. W.; Mocchiutti, E.; Morselli, A.; Mukhametshin, R.; Orsi, S.; Osteria, G.; Papini, P.; Pearce, M.; Picozza, P.; Ricci, M.; Ricciarini, S. B.; Romita, M.; Rossi, G.; Russo, S.; Schiavon, P.; Simon, M.; Sparvoli, R.; Spillantini, P.; Spinelli, P.; Stochaj, S. J.; Stozhkov, Y.; Straulino, S.; Streitmatter, R. E.; Taccetti, F.; Vacchi, A.; Vannuccini, E.; Vasilyev, G. I.; Voronov, S. A.; Wischnewski, R.; Yurkin, Y.; Zampa, G.; Zampa, N.

    2004-06-01

    PAMELA is a satellite-borne experiment that will study the antiproton and positron fluxes in cosmic rays in a wide range of energy (from 80 MeV up to 190 GeV for antiprotons and from 50 MeV up to 270 GeV for positrons) and with high statistics, and that will measure the antihelium/helium ratio with a sensitivity of the order of 10/sup -8/. The detector will fly on-board a polar orbiting Resurs DK1 satellite, which will be launched into space by a Soyuz rocket in 2004 from Baikonur cosmodrome in Kazakhstan, for a 3-year-long mission. Particle identification and energy measurements are performed in the PAMELA apparatus using the following subdetectors: a magnetic spectrometer made up of a permanent magnet equipped with double-sided microstrip silicon detectors, an electromagnetic imaging calorimeter composed of layers of tungsten absorber and silicon detectors planes, a transition radiation detector made of straw tubes interleaved with carbon fiber radiators, a plastic scintillator time-of-flight and trigger system, a set of anticounter plastic scintillator detectors, and a neutron detector. The features of the detectors and the main results obtained in beam test sessions are presented.

  16. Measurements of the dose due to cosmic rays in aircraft

    International Nuclear Information System (INIS)

    Vukovic, B.; Lisjak, I.; Radolic, V.; Vekic, B.; Planinic, J.

    2006-01-01

    When the primary particles from space, mainly protons, enter the atmosphere, they produce interactions with air nuclei, and cosmic-ray showers are induced. The radiation field at aircraft altitude is complex, with different types of particles, mainly photons, electrons, positrons and neutrons, with a large energy range. The cosmic radiation dose aboard A320 and ATR 42 aircraft was measured with TLD-100 (LiF:Mg,Ti) detectors and the Mini 6100 semiconductor dosimeter; radon concentration in the atmosphere was measured with the Alpha Guard radon detector. The estimated occupational effective dose for the aircraft crew (A320) working 500 h per year was 1.64 mSv. Another experiment was performed by the flights Zagreb-Paris-Buenos Aires and reversely, when one measured cosmic radiation dose; for 26.7 h of flight, the TLD dosimeter registered the total dose of 75 μSv and the average dose rate was 2.7 μSv/h. In the same month, February 2005, a traveling to Japan (24 h flight: Zagreb-Frankfurt-Tokyo and reversely) and the TLD-100 measurement showed the average dose rate of 2.4 μSv/h

  17. Measurements of the dose due to cosmic rays in aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Vukovic, B. [Department of Physics, University of Osijek, Osijek, P.O. Box 125 (Croatia); Lisjak, I. [Croatia Airlines, Zagreb (Croatia); Radolic, V. [Department of Physics, University of Osijek, Osijek, P.O. Box 125 (Croatia); Vekic, B. [Rudjer Boskovic Institute, Zagreb (Croatia); Planinic, J. [Department of Physics, University of Osijek, Osijek, P.O. Box 125 (Croatia)]. E-mail: planinic@ffos.hr

    2006-06-15

    When the primary particles from space, mainly protons, enter the atmosphere, they produce interactions with air nuclei, and cosmic-ray showers are induced. The radiation field at aircraft altitude is complex, with different types of particles, mainly photons, electrons, positrons and neutrons, with a large energy range. The cosmic radiation dose aboard A320 and ATR 42 aircraft was measured with TLD-100 (LiF:Mg,Ti) detectors and the Mini 6100 semiconductor dosimeter; radon concentration in the atmosphere was measured with the Alpha Guard radon detector. The estimated occupational effective dose for the aircraft crew (A320) working 500 h per year was 1.64 mSv. Another experiment was performed by the flights Zagreb-Paris-Buenos Aires and reversely, when one measured cosmic radiation dose; for 26.7 h of flight, the TLD dosimeter registered the total dose of 75 {mu}Sv and the average dose rate was 2.7 {mu}Sv/h. In the same month, February 2005, a traveling to Japan (24 h flight: Zagreb-Frankfurt-Tokyo and reversely) and the TLD-100 measurement showed the average dose rate of 2.4 {mu}Sv/h.

  18. The role of cosmic rays in the Earth's atmospheric processes

    Indian Academy of Sciences (India)

    Cosmic rays; global electric circuit; ion-aerosol; cloud variation; weather and ... layers have also significant effect on the Earth's atmosphere heat balance .... Numerical modelling and satellite observations suggested that a 1% change in the.

  19. Cosmic Ray Results from the CosmoALEPH Experiment

    CERN Document Server

    Grupen, C; Jost, B; Maciuc, F; Luitz, S; Mailov, A; Müller, A S; Putzer, A; Rensch, B; Sander, H G; Schmeling, S; Schmelling, M; Tcaciuc, R; Wachsmuth, H; Ziegler, T; Zuber, K

    2008-01-01

    CosmoALEPH is an experiment operated in conjunction with the ALEPH detector. The ALEPH experiment took data from 1989 until the year 2000 at the Large Electron Positron Collider (LEP) at CERN. It provides, among others, high resolution tracking and calorimetry. CosmoALEPH used this e+e− detector for cosmic ray studies. In addition, six scintillator telescopes were installed in the ALEPH pit and the LEP tunnel. The whole experiment operated underground at a vertical depth of 320 meter water equivalent. Data from ALEPH and the scintillator telescopes provide informaton on the lateral distribution of energetic cosmic ray muons in extensive air showers. The decoherence curve of these remnant air shower muons is sensitive to the chemical composition of primary cosmic rays and to the interaction characteristics of energetic hadrons in the atmosphere. An attempt is made to extract the various interdependencies in describing the propagation of primary and secondary cosmic rays through the atmosphere and the rock ov...

  20. Cosmic rays score direct hits with Apollo crew

    CERN Multimedia

    1971-01-01

    Apollo 14 astronauts conduted experiments during the spaceflight to help scientists to understand why previous crews have seen flashes of light during missions, believed to be caused by cosmic rays (1 page).

  1. 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.

  2. Searches for Anisotropy of Cosmic Rays with the Telescope Array

    Science.gov (United States)

    Cady, Robert; Telescope Array Collaboration

    2016-03-01

    With over seven years of data from the TA surface detector array, we will present the results of various searches for anisotropies in the arrival direction of cosmic rays, including an update of the hotspot above 57 EeV.

  3. The acceleration of cosmic ray by shock waves

    International Nuclear Information System (INIS)

    Axford, W.I.; Leer, E.; Skadron, G.

    1977-01-01

    The acceleration of cosmic rays in flows involving shocks and other compressional waves is considered in terms of one-dimensionl, steady flows and the diffusion approximation. The results suggest that very substantial energy conversion can occur. (author)

  4. 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

  5. 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.

  6. Acceleration of cosmic rays in SNR shock waves

    International Nuclear Information System (INIS)

    Drury, L.O'C.; Markiewicz, W.J.; Voelk, H.J.

    1988-01-01

    The time dependence of the energy density of cosmic rays accelerated in the outer shock of a supernova is studied in simple nonlinear models. The solutions are classified in their dependence on the parameters of the system. (orig.)

  7. Large vessel imaging using cosmic-ray muons

    International Nuclear Information System (INIS)

    Jenneson, P.M.

    2004-01-01

    Cosmic-ray muons are assessed for their practical use in the tomographic imaging of the internal composition of large vessels over 2 m in diameter. The technique is based on the attenuation and scattering of cosmic-ray muons passing through a vessel and has advantages over photon-based methods of tomography that it is extendable to object containing high-density materials over many tens of metres. The main disadvantage is the length of time required to produce images of sufficient resolution and hence cosmic ray muon tomography will be most suited to the imaging of large structures whose internal composition is effectively static for the duration of the imaging period. Simulation and theoretical results are presented here which demonstrate the feasibility of cosmic ray muon tomography

  8. Gamma-ray astronomy and cosmic-ray origin theory

    International Nuclear Information System (INIS)

    Ginzburg, V.L.

    1973-01-01

    A theory of the origin of cosmic radiation is discussed in light of the advances made in gamma-ray astronomy. Arguments against metagalactic models for the origin of cosmic rays are emphasized. (U.S.)

  9. Detectors of Cosmic Rays, Gamma Rays, and Neutrinos

    International Nuclear Information System (INIS)

    Altamirano, A.; Navarra, G.

    2009-01-01

    We summarize the main features, properties and performances of the typical detectors in use in Cosmic Ray Physics. A brief historical and general introduction will focus on the main classes and requirements of such detectors.

  10. The latitude distribution of cosmic rays at sea level during 1976

    International Nuclear Information System (INIS)

    Potgieter, M.S.

    1978-12-01

    During the 1976 period of maximum intensity of cosmic rays a latitude survey was carried out at sea level with two neutron monitors and a neutron moderated detector on board the S.A. Huguenot of Safmarine. The survey lasted for eleven months from December 1975 to November 1976 and a cutoff rigidity range from 1,8 GV (New York) to 17 GV (Singapore) was covered. The second neutron monitor was designed to be more effective and less sensitive than the standard 1NM64 for the roll and pitch of a ship. A theoretical simulation model was used to compare the characteristics of the two neutron monitors and was finally compared with experimental results. The data recorded during visits to various harbours at specific cutoff rigidities were used to determine a attenuation coefficient for both monitors. The data were corrected for variations in the primary cosmic ray spectrum by using a modulations function characteristic of a period of normal modulation. The data were normalised to the relative counting rate of four reference monitor stations during October 1976. A polynomial regression analysis was used to find the best fit to the experimental data for both monitors. The differential response functions were there-upon calculated and compared. Finally the data were corrected for temperature dependence because of the constribution of muons to the counting rate of a neutron monitor. The long term correction coefficients which were used proved to be satisfactory. The difference between the temperature corrected and uncorrected response functions turned out to be less than 0,5% at 1 GV. A comparison of the 1965 and 1976 latitude distributions showed that the 1976 cosmic ray spectrum was softer compared to the previous maximum in 1965 and about the same as in 1954

  11. Probing shape coexistence in neutron-deficient $^{72}$Se via low-energy Coulomb excitation

    CERN Multimedia

    We propose to study the evolution of nuclear structure in neutron-­deficient $^{72}$Se by performing a low-­energy Coulomb excitation measurement. Matrix elements will be determined for low-­lying excited states allowing for a full comparison with theoretical predictions. Furthermore, the intrinsic shape of the ground state, and the second 0$^{+}$ state, will be investigated using the quadrupole sum rules method.

  12. 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

  13. 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

  14. 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

  15. 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.

  16. Atmospheric ionization and cosmic rays: studies and measurements before 1912

    OpenAIRE

    De Angelis, Alessandro

    2012-01-01

    The discovery of cosmic rays, a milestone in science, was based on the work by scientists in Europe and the New World and took place during a period characterised by nationalism and lack of communication. Many scientists that took part in this research a century ago were intrigued by the penetrating radiation and tried to understand the origin of it. Several important contributions to the discovery of the origin of cosmic rays have been forgotten; historical, political and personal facts migh...

  17. 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.

  18. 11. European cosmic ray symposium held at Balatonfuered, Hungary, August 21-27, 1988

    International Nuclear Information System (INIS)

    1988-08-01

    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. Selected short communications out of 114 contributed papers were indexed separately for the INIS database. (R.P.)

  19. 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.)

  20. Cosmic-ray anisotropy studies with IceCube

    Science.gov (United States)

    McNally, Frank

    2014-03-01

    The IceCube neutrino observatory detects tens of billions of energetic muons per year produced by cosmic-ray interactions with the atmosphere. The size of this sample has allowed IceCube to observe a significant anisotropy in arrival direction for cosmic rays with median energies between 20 and 400 TeV. This anisotropy is characterized by a large scale structure of per-mille amplitude accompanied by structures with smaller amplitudes and with typical angular sizes between 10° and 20°. IceTop, the surface component of IceCube, has observed a similar anisotropy in the arrival direction distribution of cosmic rays, extending the study to PeV energies. The better energy resolution of IceTop allows for additional studies of the anisotropy, for example a comparison of the energy spectrum in regions of a cosmic-ray excess or deficit to the rest of the sky. We present an update on the cosmic-ray anisotropy observed with IceCube and IceTop and the results of first studies of the energy spectrum at locations of cosmic-ray excess or deficit.

  1. 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.

  2. 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)

  3. 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

  4. 37Ar and 39Ar in meteorites and the spatial cosmic ray gradient

    International Nuclear Information System (INIS)

    Heusser, G.; Schaeffer, O.A.

    1977-01-01

    Cosmic-ray-produced 37 Ar (tsub(1/2) = 35 days), and 39 Ar (tsub(1/2) = 269 years) in the Fe-Ni phase of meteorites have been studied in connection with their implications for the radial gradient of cosmic ray particles. For the chondrite, Canon City, which fell on October 27, 1973, 20.1 +- 1.5 dpm/kg FeNi of 37 Ar and 22.5 +- 1.4 dpm/kg FeNi of 39 Ar was found. Usually, the 37 Ar/ 39 Ar ratio is used to deduce a spatial gradient. However, 37 Ar data reported in the literature are inconsistent. They fluctuate much more than could be accounted for by different orbits and the anticipated correlation with the cosmic ray neutron registrations is rather weak. Consequently, the 37 Ar/ 39 Ar-derived gradient has a low confidence level. On the other hand, 39 Ar activities group close to a mean value of 22.5 dpm/kg FeNi and appear to be almost independent of the different meteoroid orbits. A comparison of measured 39 Ar activities in meteorites with those calculated for orbits obtained from fireball data shows that a gradient of 10%/Au or less is reconcilable with the experimental findings. The average gradient (E > 200 MeV) during the last 500 years was probably not much larger than that measured presently by the Pioneer 10 and 11, and Helios spacecrafts. (Auth.)

  5. Elastic scattering of polarized neutrons by 3He at low energy

    International Nuclear Information System (INIS)

    Drigo, L.; Tornielli, G.; Zannoni, G.

    1982-01-01

    Elastic scattering by 3 He for 1.67, 2.43, 3.0, 3.4 and 7.8 MeV neutron beams of known polarization was measured at seven angles from 25 0 to 155 0 using a high pressure gas scintillation counter. The geometrical and multiple scattering effects were accounted for by the Monte Carlo technique. The corrected results were compared with previous experimental data and with the existing predictions based on microscopic calculations and phenomenological analyses. (author)

  6. 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.

  7. Cosmic Ray Anomalies from the MSSM?

    Energy Technology Data Exchange (ETDEWEB)

    Cotta, R.C.; /SLAC; Conley, J.A.; /Bonn U.; Gainer, J.S.; /Argonne /Northwestern U.; Hewett, J.L.; Rizzo, T.G.; /SLAC

    2011-08-11

    The recent positron excess in cosmic rays (CR) observed by the PAMELA satellite may be a signal for dark matter (DM) annihilation. When these measurements are combined with those from FERMI on the total (e{sup +} + e{sup -}) ux and from PAMELA itself on the {anti p}p ratio, these and other results are difficult to reconcile with traditional models of DM, including the conventional minimal Supergravity (mSUGRA) version of Supersymmetry even if boosts as large as 10{sup 3-4} are allowed. In this paper, we combine the results of a previously obtained scan over a more general 19-parameter subspace of the Minimal Supersymmetric Standard Model (MSSM) with a corresponding scan over astrophysical parameters that describe the propagation of CR. We then ascertain whether or not a good fit to this CR data can be obtained with relatively small boost factors while simultaneously satisfying the additional constraints arising from gamma ray data. We find that a specific subclass of MSSM models where the Lightest Supersymmetric Particle (LSP) is mostly pure bino and annihilates almost exclusively into {tau} pairs comes very close to satisfying these requirements. The lightest in this set of models is found to be relatively close in mass to the LSP and is in some cases the nLSP. These models lead to a significant improvement in the overall fit to the data by {approx}1 unit of {chi}{sup 2}/dof in comparison to the best fit without Supersymmetry while employing boosts in the range {approx}100-200. The implications of these models for future experiments are discussed.

  8. On unambiguous parametrization of neutron cross-sections in the low-energy region

    International Nuclear Information System (INIS)

    Novoselov, G.M.; Kolomiets, V.M.

    1982-08-01

    One of the most important aims of analysis in the resonance region is the evaluation of neutron resonance parameters on the basis of a given formalism of the theory of nuclear reactions. However, the task of finding resonance parameters from experimental data on the energy dependence of cross-sections is subject to a number of difficulties. These difficulties are not only of a theoretical character associated with the selection of one version or another of the theory taking into account the effects necessary (interference between resonances, Doppler effect etc.), but also involve problems of principle. Whether the set of parameters found is the only possible one within the context of a single formalism used remains open. The specific features of processing the experimental data are such that even with good resolution a number of overlapping resonances (occurring as a result of the fluctuation in inter-level distances or the Doppler effect) may be classified as an isolated resonance. Moreover, even given a very weak inter-level interference and Doppler effect, unambiguous parametrization of the cross-sections is not always possible. In the present paper these questions (the choice of the approximation needed for describing experimentally observed cross-sections, allowance for inter-level interference and the Doppler effect and the possibility of ambiguous reproduction of the resonance structure of cross-sections) are examined with reference to the parametrization of the total cross-sections for non-fissionable nuclei in the low-neutron-energy region

  9. 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

  10. Magnetic diffusion effects on the ultra-high energy cosmic ray spectrum and composition

    Energy Technology Data Exchange (ETDEWEB)

    Mollerach, Silvia; Roulet, Esteban, E-mail: mollerach@cab.cnea.gov.ar, E-mail: roulet@cab.cnea.gov.ar [CONICET, Centro Atómico Bariloche, Av. Bustillo 9500 (8400) (Argentina)

    2013-10-01

    We discuss the effects of diffusion of high energy cosmic rays in turbulent extra-galactic magnetic fields. We find an approximate expression for the low energy suppression of the spectrum of the different mass components (with charge Z) in the case in which this suppression happens at energies below ∼ Z EeV, so that energy losses are dominated by the adiabatic ones. The low energy suppression appears when cosmic rays from the closest sources take a time comparable to the age of the Universe to reach the Earth. This occurs for energies E < Z EeV (B/nG)√(l{sub c}/Mpc)(d{sub s}/70Mpc) in terms of the magnetic field RMS strength B, its coherence length l{sub c} and the typical separation between sources d{sub s}. We apply this to scenarios in which the sources produce a mixed composition and have a relatively low maximum rigidity (E{sub max} ∼ (2–10)Z EeV), finding that diffusion has a significant effect on the resulting spectrum, the average mass and on its spread, in particular reducing this last one. For reasonable values of B and l{sub c} these effects can help to reproduce the composition trends observed by the Auger Collaboration for source spectra compatible with Fermi acceleration.

  11. The low-energy experiment on EXOSAT

    International Nuclear Information System (INIS)

    Bleeker, J.A.M.

    1975-01-01

    The present concept of the Low-Energy-Experiment (LEE) for EXOSAT was proposed by a collaboration of the X-ray astronomy groups at Mullard Space Science Laboratories at University College London, the Space Research Laboratory at Utrecht and the Cosmic Ray Working Group at Leiden. In the following paragraphs the major characteristics of the instrumentation and the expected scientific return will be discussed. The summary comprises both the approved baseline configuration and the proposed option of a small imaging telescope

  12. Scaling in situ cosmogenic nuclide production rates using analytical approximations to atmospheric cosmic-ray fluxes

    Science.gov (United States)

    Lifton, Nathaniel; Sato, Tatsuhiko; Dunai, Tibor J.

    2014-01-01

    Several models have been proposed for scaling in situ cosmogenic nuclide production rates from the relatively few sites where they have been measured to other sites of interest. Two main types of models are recognized: (1) those based on data from nuclear disintegrations in photographic emulsions combined with various neutron detectors, and (2) those based largely on neutron monitor data. However, stubborn discrepancies between these model types have led to frequent confusion when calculating surface exposure ages from production rates derived from the models. To help resolve these discrepancies and identify the sources of potential biases in each model, we have developed a new scaling model based on analytical approximations to modeled fluxes of the main atmospheric cosmic-ray particles responsible for in situ cosmogenic nuclide production. Both the analytical formulations and the Monte Carlo model fluxes on which they are based agree well with measured atmospheric fluxes of neutrons, protons, and muons, indicating they can serve as a robust estimate of the atmospheric cosmic-ray flux based on first principles. We are also using updated records for quantifying temporal and spatial variability in geomagnetic and solar modulation effects on the fluxes. A key advantage of this new model (herein termed LSD) over previous Monte Carlo models of cosmogenic nuclide production is that it allows for faster estimation of scaling factors based on time-varying geomagnetic and solar inputs. Comparing scaling predictions derived from the LSD model with those of previously published models suggest potential sources of bias in the latter can be largely attributed to two factors: different energy responses of the secondary neutron detectors used in developing the models, and different geomagnetic parameterizations. Given that the LSD model generates flux spectra for each cosmic-ray particle of interest, it is also relatively straightforward to generate nuclide-specific scaling

  13. Abnormal increase of cosmic ray on August 7th, 1972

    International Nuclear Information System (INIS)

    Kodama, Masahiro; Murakami, Kazuaki; Wada, Masami

    1974-01-01

    The abnormal increase of cosmic ray on Aug. 7th particularly the dependence of its starting time on local time was studied. Cosmic ray increased twice before and after the greatest Forbush decrease in history on August 4th and 7th, 1972. This study is a trial to estimate the anisotropic flow of solar cosmic ray from the time difference time at different places. Further, the past instance of 23 ground-level events were statistically restudied, and the relationship between the time of generation of solar cosmic ray and the time of transmission to the earth was investigated. A list is given regarding the solar cosmic ray of more than 10 9 eV which occurred since the observation had started. The list shows definite three groups. Attention is paid to the transmission time of F type which is considered to have the most simplest transmission mechanism. The dispersion of the transmission time is large regarding flare-starting time and peak wave intensity time, but is small regarding solar wave-starting time, but the dependence on the longitude is systematic. After all, cosmic ray is accelerated after 10 minutes since solar electric wave has started, and arrives at the earth most early in the case of a flare occurred at the root of garden force line toward the earth. In conclusion, the method of studying the difference of the starting time of abnormal increase according to local time may be an effective means for examining in the characteristics of anisotropic flow of solar cosmic ray. (Iwakiri, K.)

  14. Radar detection of ultra high energy cosmic rays

    Science.gov (United States)

    Myers, Isaac J.

    TARA (Telescope Array Radar) is a cosmic ray radar detection experiment co-located with Telescope Array, the conventional surface scintillation detector (SD) and fluorescence telescope detector (FD) near Delta, UT. The TARA detector combines a 40 kW transmitter and high gain transmitting antenna which broadcasts the radar carrier over the SD array and in the FD field of view to a 250 MS/s DAQ receiver. Data collection began in August, 2013. TARA stands apart from other cosmic ray radar experiments in that radar data is directly compared with conventional cosmic ray detector events. The transmitter is also directly controlled by TARA researchers. Waveforms from the FD-triggered data stream are time-matched with TA events and searched for signal using a novel signal search technique in which the expected (simulated) radar echo of a particular air shower is used as a matched filter template and compared to radio waveforms. This technique is used to calculate the radar cross-section (RCS) upper-limit on all triggers that correspond to well-reconstructed TA FD monocular events. Our lowest cosmic ray RCS upper-limit is 42 cm2 for an 11 EeV event. An introduction to cosmic rays is presented with the evolution of detection and the necessity of new detection techniques, of which radar detection is a candidate. The software simulation of radar scattering from cosmic rays follows. The TARA detector, including transmitter and receiver systems, are discussed in detail. Our search algorithm and methodology for calculating RCS is presented for the purpose of being repeatable. Search results are explained in context of the usefulness and future of cosmic ray radar detection.

  15. Effect of neutron irradiation on the density of low-energy excitations in vitreous silica

    International Nuclear Information System (INIS)

    Smith, T.L.

    1979-01-01

    Systematic low-temperature measurements of the thermal conductivity, specific heat, dielectric constant, and temperature-dependent ultrasound velocity were made on a single piece of vitreous silica. These measurements were repeated after fast neutron irradiation of the material. It was found that the irradiation produced changes of the same relative magnitude in the low-temperature excess specific heat C/sub ex/, the thermal conductivity kappa, and the anomalous temperature dependence of the ultrasound velocity Δv/v. A corresponding change in the temperature dependent dielectric constant was not observed. It is therefore likely that kappa and Δv/v are determined by the same localized excitations responsible for C/sub ex/, but the temperature dependence of the dielectric constant may have a different, though possibly related, origin. A consistent account for the measured C/sub ex/, kappa, and Δv/v of unirradiated silica is given by the tunneling-state model with a single, energy-dependent density of states. Changes in these three properties due to irradiation can be explained by altering only the density of tunneling states incorporated in the model

  16. Solid-state effects on thermal-neutron cross sections and on low-energy resonances

    International Nuclear Information System (INIS)

    Harvey, J.A.; Mook, H.A.; Hill, N.W.; Shahal, O.

    1982-01-01

    The neutron total cross sections of several single crystals (Si, Cu, sapphire), several polycrystalline samples (Cu, Fe, Be, C, Bi, Ta), and a fine-powder copper sample have been measured from 0.002 to 5 eV. The Cu powder and polycrystalline Fe, Be and C data exhibit the expected abrupt changes in cross section. The cross section of the single crystal of Si is smooth with only small broad fluctuations. The data on two single Cu crystals, the sapphire crystal, cast Bi, and rolled samples of Ta and Cu have many narrow peaks approx. 10 -3 eV wide. High resolution (0.3%) transmission measurements were made on the 1.057-eV resonance in 240 Pu and the 0.433-eV resonance in 180 Ta, both at room and low temperatures to study the effects of crystal binding. Although the changes in Doppler broadening with temperature were apparent, no asymmetries due to a recoilless contribution were observed

  17. On the possibility of highest energy cosmic rays bursts and their correlation with gamma rays bursts e.g. March 5th, 1979 event

    International Nuclear Information System (INIS)

    Drukier, K.

    1982-01-01

    The avalanche production of magnetic monopoles is possible in neutron stars. Big part of the magnetic field energy can be used to accelerate a pulse of 10 30 monopoles to the energy E > approximately 10 17 eV. Thus the neutron stars may be ''point'' sources of bursts of highest energy Cosmic Rays. The emission of brehmsstrahlung photons by these highly relativistic monopoles would be seen as X and gamma bursts. This ''exotic'' model for March 5th, 1979 event, predicts that it has been followed by burst of highest energy Cosmic Rays coming from the direction of LMC supernovae remanent N49

  18. The acceleration rate of cosmic rays at cosmic ray modified shocks

    Science.gov (United States)

    Saito, Tatsuhiko; Hoshino, Masahiro; Amano, Takanobu

    It is a still controversial matter whether the production efficiency of cosmic rays (CRs) is relatively efficient or inefficient (e.g. Helder et al. 2009; Hughes et al. 2000; Fukui 2013). In upstream region of SNR shocks (the interstellar medium), the energy density of CRs is comparable to a substantial fraction of that of the thermal plasma (e.g. Ferriere 2001). In such a situation, CRs can possibly exert a back-reaction to the shocks and modify the global shock structure. These shocks are called cosmic ray modified shocks (CRMSs). In CRMSs, as a result of the nonlinear feedback, there are almost always up to three steady-state solutions for given upstream parameters, which are characterized by CR production efficiencies (efficient, intermediate and inefficient branch). We evaluate qualitatively the efficiency of the CR production in SNR shocks by considering the stability of CRMS, under the effects of i) magnetic fields and ii) injection, which play significant roles in efficiency of acceleration. By adopting two-fluid model (Drury & Voelk, 1981), we investigate the stability of CRMSs by means of time-dependent numerical simulations. As a result, we show explicitly the bi-stable feature of these multiple solutions, i.e., the efficient and inefficient branches are stable and the intermediate branch is unstable, and the intermediate branch transit to the inefficient one. This feature is independent of the effects of i) shock angles and ii) injection. Furthermore, we investigate the evolution from a hydrodynamic shock to CRMS in a self-consistent manner. From the results, we suggest qualitatively that the CR production efficiency at SNR shocks may be the least efficient.

  19. The Bess Investigation of the Origin of Cosmic-ray Antiprotons and Search for Cosmological Antimatter

    Science.gov (United States)

    Mitchell, John; Yamamoto, Akira; Yoshimura, Koji; Makida, Yasuhiro; Matsuda, Shinya; Hasegawa, Masaya; Horikoshi, Atsushi; Tanaka,Ken-ichi; Suzuki, Junichi; Nishimura, Jun; hide

    2008-01-01

    The Balloon-borne Experiment with a Superconducting Spectrometer (BESS) collaboration has made precise measurements of the spectra of cosmic ray antiprotons and light nuclei and conducted a sensitive search for antinuclei. Ten BESS high-latitude flights, eight from Canada and two from Antarctica, span more than a Solar cycle between 1993 and 2007/2008. BESS measurements of low-energy antiprotons constrain candidate models for dark matter including the possible signature of primordial black hole evaporation. The stringent BESS measurements of antiprotons and the elemental and isotopic spectra of H and He provide strong constraints on models of cosmic-ray transport in the Galaxy and Solar System. BESS has also reported the first antideuterium upper limit. BESS employs a superconducting magnetic-rigity spectrometer with time-of-flight and aerogel Cherenkov detectors to identify incident particles by charge, charge sign, mass, and energy. The BESS-Polar long-duration instrument has reduced lower energy limit of 100 MeV (top of the atmosphere) to increase its sensitivity to possible primary antiproton sources. BESS-Polar II was rebuilt with extended magnet lifetime, improved detector and electronic performance, and greater data storage capacity. It was flown fro Antarctica December 2007-January 2008, recording about 4.6 bission events during 24.5 days at float altitude with the magnet on. During the flight the influence of a high-speed stream in the Solar wind was observed. Details of the BESS-Polar II instrument and flight performance are reported elsewhere at this conference. The successful BESS-Polar II flight at Solar minimum is especially important. Most cosmic-ray antiprotons are secondary products of nuclear interactions of primary cosmic-ray nuclei with the interstellar gas, giving a spectrum that peaks at about 2 GeV and falls rapidly to higher and lower energies. However, BESS data taken in the previous Solar minimum show a small excess over secondary

  20. Neutron emission effects on final fragments mass and kinetic energy distribution from low energy fission of 234U

    International Nuclear Information System (INIS)

    Montoya, M.; Rojas, J.; Lobato, I.

    2008-01-01

    The standard deviation of the final kinetic energy distribution (σ e ) as a function of mass of final fragments (m) from low energy fission of 234 U, measured with the Lohengrin spectrometer by Belhafaf et al., presents a peak around m = 109 and another around m = 122. The authors attribute the first peak to the evaporation of a large number of neutrons around the corresponding mass number, i.e. there is no peak on the standard deviation of the primary kinetic energy distribution (σ E ) as a function of primary fragment mass (A). The second peak is attributed to a real peak on σ E (A). However, theoretical calculations related to primary distributions made by H.R. Faust and Z. Bao do not suggest any peak on σ E (A). In order to clarify this apparent controversy, we have made a numerical experiment in which the masses and the kinetic energy of final fragments are calculated, assuming an initial distribution of the kinetic energy without structures on the standard deviation as function of fragment mass. As a result we obtain a pronounced peak on σ e (m) curve around m = 109, a depletion from m = 121 to m = 129, and an small peak around m = 122, which is not as great as that measured by Belhafaf et al. Our simulation also reproduces the experimental results on the yield of the final mass Y(m), the average number of emitted neutrons as a function of the provisional mass (calculated from the values of the final kinetic energy of the complementary fragments) and the average value of fragment kinetic energy as a function of the final mass. From our results we conclude that there are no peaks on the σ E (A) curve, and the observed peaks on σ e (m) are due to the emitted neutron multiplicity and the variation of the average fragment kinetic energy as a function of primary fragment mass. (Author)

  1. 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.

  2. 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

  3. 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)

  4. 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)

  5. 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...

  6. 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.

  7. Experimental Summary: Very High Energy Cosmic Rays and their Interactions

    Directory of Open Access Journals (Sweden)

    Kampert Karl-Heinz

    2013-06-01

    Full Text Available The XVII International Symposium on Very High Energy Cosmic Ray Interactions, held in August of 2012 in Berlin, was the first one in the history of the Symposium,where a plethora of high precision LHC data with relevance for cosmic ray physics was presented. This report aims at giving a brief summary of those measurements andit discusses their relevance for observations of high energy cosmic rays. Enormous progress has been made also in air shower observations and in direct measurements of cosmic rays, exhibiting many more structure in the cosmic ray energy spectrum than just a simple power law with a knee and an ankle. At the highest energy, the flux suppression may not be dominated by the GZK-effect but by the limiting energy of a nearby source or source population. New projects and application of new technologies promise further advances also in the near future. We shall discuss the experimental and theoretical progress in the field and its prospects for coming years.

  8. Cosmic rays and other space phenomena dangerous for the Earth's civilization: Foundation of cosmic ray warning system and beginning steps

    Science.gov (United States)

    Lev, Dorman

    2016-07-01

    This report is an example how fundamental research in Cosmic Ray (CR) Astrophysics and Geophysics can be applied to very important modern practical problem: monitoring by CR space weather and prediction by using on-line CR data space phenomena dangerous for satellites electronics and astronauts health in the space, for crew and passengers health on commercial jets in atmosphere (altitude about 10 km and higher), and in some rare cases for technology and people health on the ground, prediction on the role of CR and other space weather factors in climate change and influence on agriculture production. It is well known that in periods of great SEP (Solar Energetic Particle) events, the fluxes can be so big that memory of computers and other electronics in space may be destroyed, satellites and spaceships became dead (each year Insurance Companies paid billions dollars for these failures (if will be event as February 23, 1956, will be destroyed about all satellites in few hours, the price of this will be more than 10-20 billion dollars, will be total destroying satellite communications and a rose a lot of other problems). In periods of great SEP events is necessary to switch off some part of electronics for short time to protect computer memories. These periods are also dangerous for astronauts on space-ships, and International Space Station (ISS), passengers and crew in commercial jets (especially during S5-S7 radiation storms). The problem is how to forecast exactly these dangerous phenomena. We show that exact forecast can be made by using high-energy particles (about 2-10 GeV/nucleon and higher) which transportation from the Sun is characterized by much bigger diffusion coefficient than for small and middle energy particles. Therefore high energy particles came from the Sun much more early (8-20 minutes after acceleration and escaping into solar wind) than main part of smaller energy particles caused dangerous situation for electronics and people health (about 60

  9. 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

  10. DAMPE: A gamma and cosmic ray observatory in space

    Science.gov (United States)

    D'Urso, D.; Dampe Collaboration

    2017-05-01

    DAMPE (DArk Matter Particle Explorer) is one of the five satellite missions in the framework of the Strategic Pioneer Research Program in Space Science of the Chinese Academy of Sciences (CAS). Launched on December 17th 2015 at 08:12 Beijing time, it is taking data into a sun-synchronous orbit, at the altitude of 500km. The main scientific objective of DAMPE is to detect electrons and photons in the range 5GeV-10TeV with unprecedented energy resolution, in order to identify possible Dark Matter signatures. It will also measure the flux of nuclei up to 100TeV with excellent energy resolution. The satellite is equipped with a powerful space telescope for high energy gamma-ray, electron and cosmic rays detection. It consists of a plastic scintillator strips detector (PSD) that serves as anti-coincidence detector, a silicon-tungsten tracker (STK), a BGO imaging calorimeter of about 32 radiation lengths, and a neutron detector. With its excellent photon detection capability and its detector performances (at 100GeV energy resolution ˜1% , angular resolution ˜0.1° , the DAMPE mission is well placed to make strong contributions to high-energy gamma-ray observations: it covers the gap between space and ground observation; it will allow to detect a line signature in the gamma-ray spectrum, if present, in the sub-TeV to TeV region; it will allow a high precision gamma-ray astronomy. A report on the mission goals and status will be discussed, together with in-orbit first data coming from space.

  11. Radiation transport of cosmic ray nuclei in lunar material and radiation doses

    International Nuclear Information System (INIS)

    Silberberg, R.; Tsao, C.H.; Adams, J.H. Jr.; Letaw, J.R.

    1985-01-01

    The radiation environment on the lunar surface is inhospitable. The permanent settlers may work ten hours per 24-hour interval for the two-week-long lunar day on the lunar surface, or 20 percent of the total time. At moderate depths below the lunar surface (less than 200 g/sq cm) the flux of secondary neutrons exceeds considerably that in the upper atmosphere of the earth, due to cosmic-ray interactions with lunar material. The annual dose equivalent due to neutrons is about 20 or 25 rem within the upper meter of the lunar surface. The dose equivalent due to gamma rays generated by nuclear interactions near the lunar surface is only on the order of 1 percent of that due to neutrons. However, gamma-ray line emission from excited nuclei and nuclear spallation products generated by cosmic rays near the lunar surface is of considerable interest: these lines permit the partial determination of lunar composition by gamma spectroscopy. 12 references

  12. 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.

  13. Stellar origin of the 22Ne excess in cosmic rays

    International Nuclear Information System (INIS)

    Casse, M.; Paul, J.A.

    1982-01-01

    The 22 Ne excess at the cosmic-ray source is discussed in terms of a 22 Ne-rich component injected and accelerated by carbon-rich Wolf-Rayet stars. The overabundance of 22 Ne relative to 20 Ne predicted at the surface of these stars is estimated to a factor approx.120 with respect to solar system abundances. In order to give rise to a 22 Ne excess of about 3 at the cosmic-ray sources as inferred from observations, the carbon-rich Wolf-Rayet contribution to the primary cosmic-ray flux is to be at maximum 1/60. This component would be energized by strong stellar winds producing quasi-standing shocks around the Wolf-Rayet stars

  14. 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.

  15. 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...

  16. 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).

  17. 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.

  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. 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

  20. Four Channel Mini Wire Chamber to Study Cosmic Rays

    Science.gov (United States)

    Felix, J.; Rodriguez, G. J.

    2018-01-01

    Multiwire proportional chamber is a conventional technique to study radiation in general, and cosmic rays in particular. To study cosmic rays, it was planned, designed, constructed, characterized, and tested a four channel mini wire chamber, based on two 3 cm × 3 cm × 0.6 cm Aluminum frames, two 3 cm × 3 cm × 0.6 cm plastic frames, two 3 cm × 3 cm × 0.3 cm Aluminum frames, two electronic planes each with two Tungsten Gold plated 1 mil diameter wires, parallel and 1 cm apart each other at 25 g stretched-each plane was 90° rotated each other in the final assemble- and two Aluminum foil window to define the gas volume; it was operated with Argon 90%-CH4 10% gas mixture at 1 atmosphere and ambient temperature (20°C in the average). It is presented technical details, results on characterization, and preliminary results on cosmic rays detection.

  1. 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

  2. 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.

  3. 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

  4. 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.

  5. 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)

  6. 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)

  7. Correlation between ionospheric potential and the intensity of cosmic rays

    International Nuclear Information System (INIS)

    Meyerott, R.E.; Reagan, J.B.; Evans, J.E.

    1983-01-01

    Ionospheric potential variations with a period of about 10 yr have been observed in the data that have been acquired to date. Previous studies have shown that these variations appear to be correlated inversely with sunspot number and with solar wind velocity, and directly with cosmic ray intensity. Since the cosmic ray intensity is inversely correlated with sunspot number and solar wind velocity, these correlations all suggest that the long period variations are of solar origin. In this report it is shown that, over the limited period for which ionospheric potential measurements exist, the long period variations are better correlated with the aerosol burden injected into the stratosphere by large volcanic eruptions than with the intensity of cosmic rays. This result indicates that the long period variations in ionospheric potential are of terrestrial rather than solar origin. 20 references

  8. 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

  9. 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.

  10. 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.

  11. 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

  12. 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)

  13. 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)

  14. 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)

  15. The BESS Search for Cosmic-Ray Antiproton Origins and for Cosmological Antimatter

    Science.gov (United States)

    Mitchell, John; Yamamoto, Akira

    2009-01-01

    The apex of the Balloon-borne Experiment with a Superconducting Spectrometer (BESS) program was reached with the Antarctic flight of BESS-Polar II, during the 2007-2008 Austral Summer, that obtained 24.5 days of data on over 4.7 billion cosmic-ray events. The US-Japan BESS Collaboration uses elementary particle measurements to study the early Universe and provides fundamental data on the spectra of light cosmic-ray elements and isotopes. BESS measures the energy spectra of cosmic-ray antiprotons to investigate signatures of possible exotic sources, such as dark-matter candidates, and searches for heavier antinuclei that might reach Earth from antimatter domains formed during symmetry breaking processes in the early Universe. Since 1993, BESS has carried out eleven high-latitude balloon flights, two of long duration, that together have defined the study of antiprotons below about 4 GeV, provided standard references for light element and isotope spectra, and set the most sensitive limits on the existence of antideuterons and antihelium. The BESS-Polar II flight took place at Solar Minimum, when the sensitivity of the low-energy antiproton measurements to a primary source is greatest. The rich BESS-Polar II dataset more than doubles the combined data from all earlier BESS flights and has 10-20 times the statistics of BESS data from the previous Solar Minimum. Here, we summarize the scientific results of BESS program, focusing on the results obtained using data from the long-duration flights of BESS-Polar I (2004) and BESS-Polar II.

  16. ATLAS and ultra high energy cosmic ray physics

    Directory of Open Access Journals (Sweden)

    Pinfold James

    2017-01-01

    Full Text Available After a brief introduction to extended air shower cosmic ray physics the current and future deployment of forward detectors at ATLAS is discussed along with the various aspects of the current and future ATLAS programs to explore hadronic physics. The emphasis is placed on those results and future plans that have particular relevance for high-energy, and ultra high-energy, cosmic ray physics. The possible use of ATLAS as an “underground” cosmic muon observatory is briefly considered.

  17. Cosmic rays and space weather: effects on global climate change

    Directory of Open Access Journals (Sweden)

    L. I. Dorman

    2012-01-01

    Full Text Available We consider possible effects of cosmic rays and some other space factors on the Earth's climate change. It is well known that the system of internal and external factors formatting the climate is very unstable; decreasing planetary temperature leads to an increase of snow surface, and decrease of the total solar energy input into the system decreases the planetary temperature even more, etc. From this it follows that even energetically small factors may have a big influence on climate change. In our opinion, the most important of these factors are cosmic rays and cosmic dust through their influence on clouds, and thus, on climate.

  18. 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

  19. Horizontal cosmic ray muon radiography for imaging nuclear threats

    International Nuclear Information System (INIS)

    Morris, Christopher L.; Bacon, Jeffrey; Borozdin, Konstantin; Fabritius, Joseph; Miyadera, Haruo; Perry, John; Sugita, Tsukasa

    2014-01-01

    Muon tomography is a technique that uses information contained in the Coulomb scattering of cosmic ray muons to generate three dimension images of volumes between tracking detectors. Advantages of this technique are the muons ability to penetrate significant overburden and the absence of any additional dose beyond the natural cosmic ray flux. Disadvantages include the long exposure times and limited resolution because of the low flux. Here we compare the times needed to image objects using both vertically and horizontally mounted tracking detectors and we develop a predictive model for other geometries

  20. The acceleration of cosmic rays in supernova remnants

    International Nuclear Information System (INIS)

    Bhat, C.L.; Issa, M.R.

    1986-01-01

    The idea that the bulk of cosmic rays below 10 GeV are accelerated in supernova remnants suggests that cosmic rays should also exhibit intensity variations on a scale comparable with the linear size of a representative remnant. Following the general spirit of shock-wave acceleration models, here Monte Carlo simulations are carried out to predict what this scale should be and then corroborative evidence is presented from an autocorrelation analysis of the COS B and SAS II γ-ray data for the latitude range |b|=10-20 0 ('near Galaxy') and |b| 0 ('far Galaxy'). (author)