A Simplified Model for the Acceleration of Cosmic Ray Particles
ERIC Educational Resources Information Center
Gron, Oyvind
2010-01-01
Two important questions concerning cosmic rays are: Why are electrons in the cosmic rays less efficiently accelerated than nuclei? How are particles accelerated to great energies in ultra-high energy cosmic rays? In order to answer these questions we construct a simple model of the acceleration of a charged particle in the cosmic ray. It is not…
Ninteenth International Cosmic Ray Conference. SH Sessions, Volume 4
NASA Technical Reports Server (NTRS)
Jones, F. C. (Compiler)
1985-01-01
Papers submitted for presentation at the 19th International Cosmic Ray Conference are compiled. This volume covers solar and heliospheric phenomena, specifically, particle acceleration; cosmic ray compsotion, spectra, and anisotropy; propagation of solar and interplanetary energetic particles; solar-cycle modulation; and propagation of galactic particles in the heliosphere.
Observation of a large-scale anisotropy in the arrival directions of cosmic rays above 8 × 1018 eV
NASA Astrophysics Data System (ADS)
Pierre Auger Collaboration; Aab, A.; Abreu, P.; Aglietta, M.; Samarai, I. Al; Albuquerque, I. F. M.; Allekotte, I.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Anastasi, G. A.; Anchordoqui, L.; Andrada, B.; Andringa, S.; Aramo, C.; Arqueros, F.; Arsene, N.; Asorey, H.; Assis, P.; Aublin, J.; Avila, G.; Badescu, A. M.; Balaceanu, A.; Barbato, F.; Barreira Luz, R. J.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertaina, M. E.; Bertou, X.; Biermann, P. L.; Billoir, P.; Biteau, J.; Blaess, S. G.; Blanco, A.; Blazek, J.; Bleve, C.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Borodai, N.; Botti, A. M.; Brack, J.; Brancus, I.; Bretz, T.; Bridgeman, A.; Briechle, F. L.; Buchholz, P.; Bueno, A.; Buitink, S.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, L.; Cancio, A.; Canfora, F.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Chavez, A. G.; Chinellato, J. A.; Chudoba, J.; Clay, R. W.; Cobos, A.; Colalillo, R.; Coleman, A.; Collica, L.; Coluccia, M. R.; Conceição, R.; Consolati, G.; Contreras, F.; Cooper, M. J.; Coutu, S.; Covault, C. E.; Cronin, J.; D'Amico, S.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; de Jong, S. J.; De Mauro, G.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; Debatin, J.; Deligny, O.; Di Giulio, C.; Di Matteo, A.; Díaz Castro, M. L.; Diogo, F.; Dobrigkeit, C.; D'Olivo, J. C.; Dorosti, Q.; dos Anjos, R. C.; Dova, M. T.; Dundovic, A.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Fenu, F.; Fick, B.; Figueira, J. M.; Filipčič, A.; Fratu, O.; Freire, M. M.; Fujii, T.; Fuster, A.; Gaior, R.; García, B.; Garcia-Pinto, D.; Gaté, F.; Gemmeke, H.; Gherghel-Lascu, A.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Głas, D.; Glaser, C.; Golup, G.; Gómez Berisso, M.; Gómez Vitale, P. F.; González, N.; Gorgi, A.; Gorham, P.; Grillo, A. F.; Grubb, T. D.; Guarino, F.; Guedes, G. P.; Hampel, M. R.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huege, T.; Hulsman, J.; Insolia, A.; Isar, P. G.; Jandt, I.; Jansen, S.; Johnsen, J. A.; Josebachuili, M.; Jurysek, J.; Kääpä, A.; Kambeitz, O.; Kampert, K. H.; Katkov, I.; Keilhauer, B.; Kemmerich, N.; Kemp, E.; Kemp, J.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Kuempel, D.; Kukec Mezek, G.; Kunka, N.; Kuotb Awad, A.; LaHurd, D.; Lauscher, M.; Legumina, R.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; Lo Presti, D.; Lopes, L.; López, R.; López Casado, A.; Luce, Q.; Lucero, A.; Malacari, M.; Mallamaci, M.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Mariş, I. C.; Marsella, G.; Martello, D.; Martinez, H.; Martínez Bravo, O.; Masías Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Melo, D.; Menshikov, A.; Merenda, K.-D.; Michal, S.; Micheletti, M. I.; Middendorf, L.; Miramonti, L.; Mitrica, B.; Mockler, D.; Mollerach, S.; Montanet, F.; Morello, C.; Mostafá, M.; Müller, A. L.; Müller, G.; Muller, M. A.; Müller, S.; Mussa, R.; Naranjo, I.; Nellen, L.; Nguyen, P. H.; Niculescu-Oglinzanu, M.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nožka, L.; Núñez, L. A.; Ochilo, L.; Oikonomou, F.; Olinto, A.; Palatka, M.; Pallotta, J.; Papenbreer, P.; Parente, G.; Parra, A.; Paul, T.; Pech, M.; Pedreira, F.; Pkala, J.; Pelayo, R.; Peña-Rodriguez, J.; Pereira, L. A. S.; Perlín, M.; Perrone, L.; Peters, C.; Petrera, S.; Phuntsok, J.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porowski, C.; Prado, R. R.; Privitera, P.; Prouza, M.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Ramos-Pollan, R.; Rautenberg, J.; Ravignani, D.; Revenu, B.; Ridky, J.; Riehn, F.; Risse, M.; Ristori, P.; Rizi, V.; Rodrigues de Carvalho, W.; Rodriguez Fernandez, G.; Rodriguez Rojo, J.; Rogozin, D.; Roncoroni, M. J.; Roth, M.; Roulet, E.; Rovero, A. C.; Ruehl, P.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Saleh, A.; Salesa Greus, F.; Salina, G.; Sánchez, F.; Sanchez-Lucas, P.; Santos, E. M.; Santos, E.; Sarazin, F.; Sarmento, R.; Sarmiento, C. A.; Sato, R.; Schauer, M.; Scherini, V.; Schieler, H.; Schimp, M.; Schmidt, D.; Scholten, O.; Schovánek, P.; Schröder, F. G.; Schulz, A.; Schumacher, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sigl, G.; Silli, G.; Sima, O.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sonntag, S.; Sorokin, J.; Squartini, R.; Stanca, D.; Stanič, S.; Stasielak, J.; Stassi, P.; Strafella, F.; Suarez, F.; Suarez Durán, M.; Sudholz, T.; Suomijärvi, T.; Supanitsky, A. D.; Šupík, J.; Swain, J.; Szadkowski, Z.; Taboada, A.; Taborda, O. A.; Tapia, A.; Theodoro, V. M.; Timmermans, C.; Todero Peixoto, C. J.; Tomankova, L.; Tomé, B.; Torralba Elipe, G.; Travnicek, P.; Trini, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van Bodegom, P.; van den Berg, A. M.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Varner, G.; Vázquez, R. A.; Veberič, D.; Ventura, C.; Vergara Quispe, I. D.; Verzi, V.; Vicha, J.; Villaseñor, L.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weindl, A.; Wiencke, L.; Wilczyński, H.; Wirtz, M.; Wittkowski, D.; Wundheiler, B.; Yang, L.; Yushkov, A.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zepeda, A.; Zimmermann, B.; Ziolkowski, M.; Zong, Z.; Zuccarello, F.
2017-09-01
Cosmic rays are high-energy particles arriving from space; some have energies far beyond those that human-made particle accelerators can achieve. The sources of higher-energy cosmic rays remain under debate, although we know that lower-energy cosmic rays come from the solar wind. The Pierre Auger Collaboration reports the observation of thousands of cosmic rays with ultrahigh energies of several exa–electron volts (about a Joule per particle), arriving in a slightly dipolar distribution (see the Perspective by Gallagher and Halzen). The direction of the rays indicates that the particles originated in other galaxies and not from nearby sources within our own Milky Way Galaxy.
Multi-spectra Cosmic Ray Flux Measurement
NASA Astrophysics Data System (ADS)
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). )
AIRBORNE DETECTION AND ANALYSIS OF PRIMARY COSMIC PARTICLES WITH A SCINTILLATION DEVICE
DOE Office of Scientific and Technical Information (OSTI.GOV)
Corkhill, deP.J.; Hoffman, R.A.
1960-07-01
Data are presented as derived from telemetered irformation from a primary cosmic-particle detecting device. The data are preliminury in nature in that comparison between the cosmic-particle spectrum (as shown by the mechanical detector) was not made with similar information provided by nuclear emulsions exposed to regions of pri
Latest AMS Results on elementary particles in cosmic rays
NASA Astrophysics Data System (ADS)
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.
Cosmic ray transport in astrophysical plasmas
DOE Office of Scientific and Technical Information (OSTI.GOV)
Schlickeiser, R.
2015-09-15
Since the development of satellite space technology about 50 years ago the solar heliosphere is explored almost routinely by several spacecrafts carrying detectors for measuring the properties of the interplanetary medium including energetic charged particles (cosmic rays), solar wind particle densities, and electromagnetic fields. In 2012, the Voyager 1 spacecraft has even left what could be described as the heliospheric modulation region, as indicated by the sudden disappearance of low energy heliospheric cosmic ray particles. With the available in-situ measurements of interplanetary turbulent electromagnetic fields and of the momentum spectra of different cosmic ray species in different interplanetary environments, themore » heliosphere is the best cosmic laboratory to test our understanding of the transport and acceleration of cosmic rays in space plasmas. I review both the historical development and the current state of various cosmic ray transport equations. Similarities and differences to transport theories for terrestrial fusion plasmas are highlighted. Any progress in cosmic ray transport requires a detailed understanding of the electromagnetic turbulence that is responsible for the scattering and acceleration of these particles.« less
Laboratory Studies of Optical Characteristics and Condensation Processes of Cosmic Dust Particles
NASA Technical Reports Server (NTRS)
Spann, J. F., Jr.; Abbas, M. M.; Venturini, C. C.
2000-01-01
Information about the optical characteristics and physical processes involving cosmic dust particles is vital for interpretation of astronomical observations and an understanding of the formation and processing of dust in the evolutionary cycle of matter in the interstellar medium. Cosmic dust particles are formed in a variety of astrophysical environments such as in cool stellar outflows and circumstellar envelopes. Definitive knowledge of the nature, composition, and physical processes of cosmic dust grains, however, can only be inferred from astronomical observations through laboratory experiments on the analogs of hypothesized dust particles and with modeling calculations. Laboratory investigations of the nature, composition, and optical characteristics of cosmic dust particles are being, carried out at many institutions with a variety of experimental techniques. Despite a wealth of available data, however, many basic issues remain unresolved. An experimental facility based on suspension of dust particles in electrodynamic balance in a pressure/temperature controlled environment in a cavity has been operational at the NASA Marshall Space Flight Center, and is currently being employed for studies of dust particle charging mechanisms using electron beams and with UV radiation. In this paper, we discuss two general classes of experiments under planning stages that may be simultaneously carried out on this facility for cosmic dust investigations (i) Infrared optical characteristics (extinction coefficients and scattering phase functions) of the analogs of hypothesized of cosmic dust particles, such as natural and synthetic amorphous silicates with varying compositions, amorphous carbon grains, polycyclic aromatic hydrocarbons (PAHs), and icy core-mantle particles etc. The initial spectral range under consideration is 1-25 micrometers, to be extended to the far infrared region in the future (ii) Condensation of volatile gases on nucleus dust particles to be investigated for planetary and astrophysical environments.
Explaining TeV cosmic-ray anisotropies with non-diffusive cosmic-ray propagation
Harding, James Patrick; Fryer, Chris Lee; Mendel, Susan Marie
2016-05-11
Constraining the behavior of cosmic ray data observed at Earth requires a precise understanding of how the cosmic rays propagate in the interstellar medium. The interstellar medium is not homogeneous; although turbulent magnetic fields dominate over large scales, small coherent regions of magnetic field exist on scales relevant to particle propagation in the nearby Galaxy. Guided propagation through a coherent field is significantly different from random particle diffusion and could be the explanation of spatial anisotropies in the observed cosmic rays. We present a Monte Carlo code to propagate cosmic particle through realistic magnetic field structures. We discuss the detailsmore » of the model as well as some preliminary studies which indicate that coherent magnetic structures are important effects in local cosmic-ray propagation, increasing the flux of cosmic rays by over two orders of magnitude at anisotropic locations on the sky. Furthermore, the features induced by coherent magnetic structure could be the cause of the observed TeV cosmic-ray anisotropy.« less
EXPLAINING TEV COSMIC-RAY ANISOTROPIES WITH NON-DIFFUSIVE COSMIC-RAY PROPAGATION
DOE Office of Scientific and Technical Information (OSTI.GOV)
Harding, J. Patrick; Fryer, Chris L.; Mendel, Susan, E-mail: jpharding@lanl.gov, E-mail: fryer@lanl.gov, E-mail: smendel@lanl.gov
2016-05-10
Constraining the behavior of cosmic ray data observed at Earth requires a precise understanding of how the cosmic rays propagate in the interstellar medium. The interstellar medium is not homogeneous; although turbulent magnetic fields dominate over large scales, small coherent regions of magnetic field exist on scales relevant to particle propagation in the nearby Galaxy. Guided propagation through a coherent field is significantly different from random particle diffusion and could be the explanation of spatial anisotropies in the observed cosmic rays. We present a Monte Carlo code to propagate cosmic particle through realistic magnetic field structures. We discuss the detailsmore » of the model as well as some preliminary studies which indicate that coherent magnetic structures are important effects in local cosmic-ray propagation, increasing the flux of cosmic rays by over two orders of magnitude at anisotropic locations on the sky. The features induced by coherent magnetic structure could be the cause of the observed TeV cosmic-ray anisotropy.« less
Cosmic Rays: "A Thin Rain of Charged Particles."
ERIC Educational Resources Information Center
Friedlander, Michael
1990-01-01
Discussed are balloons and electroscopes, understanding cosmic rays, cosmic ray paths, isotopes and cosmic-ray travel, sources of cosmic rays, and accelerating cosmic rays. Some of the history of the discovery and study of cosmic rays is presented. (CW)
NASA Technical Reports Server (NTRS)
Jones, F. C. (Compiler)
1986-01-01
Invited talks, rapporteur talks, and highlight talks are included. Topics of the invited and highlight talks include astrophysical jets, gamma-ray line astronomy, cosmic rays and gamma rays in astrophysics, the early universe, elementary particle physics, solar flares and acceleration of energetic particles, cosmogenic nuclei, extragalactic astronomy, composition of solar flare particles, very high energy gamma ray sources, gamma-ray bursts, shock acceleration in the solar wind, cosmic rays in deep underground detectors, spectrum of cosmic rays at 10 to the 19th power eV, and nucleus-nucleus interactions.
The Need for Direct High-Energy Cosmic-Ray Measurements
NASA Technical Reports Server (NTRS)
Jones, Frank C.; Streitmatter, Robert
2004-01-01
Measuring the chemical composition of the cosmic rays in the energy region of greater than or equal to 10(exp 12)eV would be highly useful in settling several nagging questions concerning the propagation of cosmic rays in the galaxy. In particular an accurate measurement of secondary to primary ratios such as Boron to Carbon would gibe clear evidence as to whether the propagation of cosmic rays is determined by a diffusion coefficient that varies with the particle's energy as E(sup 0.5) or E(sup 0.3). This would go a long ways in helping us to understand the anistropy (or lack thereof) of the highest energy cosmic rays and the power requirements for producing those particles at approximately equal to 10(exp 18) eV which are believed to be highest energy particles produced in the Galaxy. This would be only one of the benefits of a mission such as ACCESS to perform direct particle measurements on very high energy cosmic rays.
NASA Astrophysics Data System (ADS)
Shapiro, M. M.
2001-08-01
Two models of cosmic-ray genesis are compared: (a) the author s red-dwarf hypothesis requiring the injection of seed particles from coronal mass ejections (CME) prior to shock acceleration, and (b) the direct acceleration of thermal ions and of grains in the ISM, proposed by Meyer, Drury and Ellison. Both models agree that shocks in the expanding envelopes of supernova remnants are principally responsible for acceleration to cosmic-ray energies. Both are designed to overcome the mismatch between the source composition of the Galactic cosmic rays (GCR) and the composition of the thermal ISM gas. Model (a) utilizes the prolific emissions of energetic particles from active dMe and dKe stars via their CME as the agents of seed-particle injection into the ISM. The composition of these seed particles is governed by the FIP (first-ionization potential) selection mechanism that operates for both Galactic cosmic rays and solar energetic particles. Hence it is consistent with the cosmic-ray source composition. Model (b) relies on the sputtering and acceleration of grains in the ISM (along with acceleration of thermal ions) to provide the known source composition. This model considers the FIP ordering of GCR abundances as purely coincidental, and it attributes the relative source abundances to selection according to volatility. Recent cosmic-ray observations in favor of each model are cited.
NASA Astrophysics Data System (ADS)
Bressler, Matthew; Goodwin, Lydia; Kryemadhi, Abaz
2017-11-01
Cosmic ray muons are produced when high energy particles interact with nuclei in Earth's atmosphere. Muons make up the majority of charged particles that reach sea level and are the only particles (apart from neutrinos) that can penetrate to significant depths underground. The muon flux underground decreases approximately exponentially as a function of depth. We use a cosmic ray detector developed by the QuarkNet Program at Fermi National Laboratory to map the topography of the mountain above an abandoned Pennsylvania Turnpike tunnel by analyzing muon flux at different rock overburdens. Cosmic ray muons have been used in this capacity before to search for hidden chambers in pyramids and for mapping volcanoes. This study provides a unique field experience to learn about particle physics and particle detectors, which could be of interest to students and teachers in physics.
High energy particles and quanta in astrophysics
NASA Technical Reports Server (NTRS)
Mcdonald, F. B. (Editor); Fichtel, C. E.
1974-01-01
The various subdisciplines of high-energy astrophysics are surveyed in a series of articles which attempt to give an overall view of the subject as a whole by emphasizing the basic physics common to all fields in which high-energy particles and quanta play a role. Successive chapters cover cosmic ray experimental observations, the abundances of nuclei in the cosmic radiation, cosmic electrons, solar modulation, solar particles (observation, relationship to the sun acceleration, interplanetary medium), radio astronomy, galactic X-ray sources, the cosmic X-ray background, and gamma ray astronomy. Individual items are announced in this issue.
NASA Technical Reports Server (NTRS)
Benton, E. V.; Frank, A. L.; Benton, E. R.; Marenny, A. M.; Nymmik, R. A.; Suslov, A. A.
1995-01-01
Fluxes of cosmic ray particles with different LET values were measured on board the COSMOS-2044 biosatellite under various thicknesses of shielding by stacks of CR-39 and nitrocellulose plastic nuclear track detectors (mounted outside the satellite). The component composition of the particles detected under shieldings of 0.1-2.5 g cm(exp -2) is verified by comparing experimental data with the results of model simulations of the fluxes of galactic cosmic ray particles and of radiation belt protons.
NASA Technical Reports Server (NTRS)
Marenny, A. M.; Nymmik, R. A.; Suslov, A. A.; Benton, E. V.; Frank, A. L.; Benton, E. R.
1992-01-01
Fluxes of cosmic ray particles with different LET values were measured on board the Cosmos-2044 biosatellite under various thicknesses of shielding by stacks of CR-39 and nitrocellulose plastic nuclear track detectors (mounted outside the satellite). The component composition of the particles detected under shieldings of 0.1-2.5 g cm-2 is verified by comparing experimental data with the results of model simulations of the fluxes of galactic cosmic ray particles and of radiation belt protons.
On the size and velocity distribution of cosmic dust particles entering the atmosphere
Carrillo‐Sánchez, J. D.; Feng, W.; Nesvorný, D.; Janches, D.
2015-01-01
Abstract The size and velocity distribution of cosmic dust particles entering the Earth's atmosphere is uncertain. Here we show that the relative concentrations of metal atoms in the upper mesosphere, and the surface accretion rate of cosmic spherules, provide sensitive probes of this distribution. Three cosmic dust models are selected as case studies: two are astronomical models, the first constrained by infrared observations of the Zodiacal Dust Cloud and the second by radar observations of meteor head echoes; the third model is based on measurements made with a spaceborne dust detector. For each model, a Monte Carlo sampling method combined with a chemical ablation model is used to predict the ablation rates of Na, K, Fe, Mg, and Ca above 60 km and cosmic spherule production rate. It appears that a significant fraction of the cosmic dust consists of small (<5 µg) and slow (<15 km s−1) particles. PMID:27478282
Anomalous Transport of Cosmic Rays in a Nonlinear Diffusion Model
DOE Office of Scientific and Technical Information (OSTI.GOV)
Litvinenko, Yuri E.; Fichtner, Horst; Walter, Dominik
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 treatmentmore » 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.« less
NASA Technical Reports Server (NTRS)
Blanford, G. E., Jr.; Friedlander, M. W.; Hoppe, M.; Klarmann, J.; Walker, R. M.; Wefel, J. P.
1974-01-01
Large areas of nuclear emulsions and plastic detectors were exposed to the primary cosmic radiation during high-altitude balloon flights. From an analysis of 141 particle tracks recorded during a total exposure of 13,000,000 sq m-ster-sec, a charge spectrum of the VVH particles has been derived.
Mining cosmic dust from the blue ice lakes of Greenland
NASA Technical Reports Server (NTRS)
Maurette, M.; Brownlee, D. E.; Fehrenback, L.; Hammer, C.; Jehano, C.; Thomsen, H. H.
1985-01-01
Extraterrestrial material, most of which invisible settles to Earth's surface as dust particles smaller than a millimeter in size were investigated. Particles of 1/10 millimeter size fall at a rate of one/sq m/yr collection of extraterrestrial dust is important because the recovered cosmic dust particles can provide important information about comets. Comets are the most important source of dust in the solar system and they are probably the major source of extraterrestrial dust that is collectable at the Earth's surface. A new collection site for cosmic dust, in an environment where degradation by weathering is minimal is reported. It is found that the blue ice lakes on the Greenland ice cap provide an ideal location for collection of extraterrestrial dust particles larger than 0.1 mm in size. It is found that the lakes contain large amounts of cosmic dust which is much better preserved than similar particles recovered from the ocean floor.
Research in particles and fields. [cosmic rays, gamma rays, and cosmic plasma
NASA Technical Reports Server (NTRS)
Stone, E. C.; Buffington, A.; Davis, L., Jr.; Prince, T. A.; Vogt, R. E.
1984-01-01
Research activities in cosmic rays, gamma rays, and astrophysical plasmas are reviewed. Energetic particle and photon detector systems flown on spacecraft and balloons were used to carry out the investigations. Specific instruments mentioned are: the high energy isotope spectrometer telescope, the electron/isotope spectrometer, the heavy isotope spectrometer telescope, and magnetometers. Solar flares, planetary magnetospheres, element abundance, the isotopic composition of low energy cosmic rays, and heavy nuclei are among the topics receiving research attention.
The dawn of the particle astronomy era in ultra-high-energy cosmic rays.
Bauleo, Pablo M; Martino, Julio Rodríguez
2009-04-16
Cosmic rays are charged particles arriving at the Earth from space. Those at the highest energies are particularly interesting because the physical processes that could create or accelerate them are at the limit of our present knowledge. They also open the window to particle astronomy, as the magnetic fields along their paths are not strong enough to deflect their trajectories much from a straight line. The Pierre Auger Observatory is the largest cosmic-ray detector on Earth, and as such is beginning to resolve past observational disagreements regarding the origin and propagation of these particles.
Cosmic dust or other similar outer-space particles location detector
NASA Technical Reports Server (NTRS)
Aver, S.
1973-01-01
Cosmic dust may be serious radiation hazard to man and electronic equipment caught in its path. Dust detector uses two operational amplifiers and offers narrower areas for collection of cosmic dust. Detector provides excellent resolution as result of which recording of particle velocities as well as positions of their impact are more accurately determined.
NASA Technical Reports Server (NTRS)
Blanford, G. E., Jr.; Friedlander, M. W.; Hoppe, M.; Klarmann, J.; Walker, R. M.; Wefel, J. P.
1972-01-01
Large areas of nuclear emulsions and plastic detectors were exposed to the primary cosmic radiation during high altitude balloon flights. From the analysis of 141 particle tracks recorded during a total exposure of 1.3 x 10 to the 7th power sq m ster.sec., a charge spectrum of the VVH particles has been derived.
Frontiers in In-Situ Cosmic Dust Detection and Analysis
NASA Astrophysics Data System (ADS)
Sternovsky, Zoltán; Auer, Siegfried; Drake, Keith; Grün, Eberhard; Horányi, Mihály; Le, Huy; Srama, Ralf; Xie, Jianfeng
2011-11-01
In-situ cosmic dust instruments and measurements played a critical role in the emergence of the field of dusty plasmas. The major breakthroughs included the discovery of β-meteoroids, interstellar dust particles within the solar system, Jovian stream particles, and the detection and analysis of Enceladus's plumes. The science goals of cosmic dust research require the measurements of the charge, the spatial, size and velocity distributions, and the chemical and isotopic compositions of individual dust particles. In-situ dust instrument technology has improved significantly in the last decade. Modern dust instruments with high sensitivity can detect submicron-sized particles even at low impact velocities. Innovative ion optics methods deliver high mass resolution, m/dm>100, for chemical and isotopic analysis. The accurate trajectory measurement of cosmic dust is made possible even for submicron-sized grains using the Dust Trajectory Sensor (DTS). This article is a brief review of the current capabilities of modern dust instruments, future challenges and opportunities in cosmic dust research.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Karelin, A. V., E-mail: karelin@hotbox.ru; Borisov, S. V.; Voronov, S. A.
2013-06-15
The PAMELA satellite-borne experiment is designed to study cosmic rays over a broad energy range. The apparatus has been in near-Earth cosmic space from June 2006 to the present time. It is equipped with a magnetic spectrometer for determining the sign of the particle charge and rigidity. In solving some problems, however, information from the magnetic spectrometer becomes inaccessible, so that it is necessary to employ a calorimeter to separate the electron and nuclear cosmic-ray components. A procedure for separating these components for particles arriving off the magnetic-spectrometer aperture is considered.
Catching Cosmic Rays with a DSLR
ERIC Educational Resources Information Center
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…
The Birth of Elementary-Particle Physics.
ERIC Educational Resources Information Center
Brown, Laurie M.; Hoddeson, Lillian
1982-01-01
Traces the origin and development of particle physics, concentrating on the roles of cosmic rays and theory. Includes charts highlighting significant events in the development of cosmic-ray physics and quantum field theory. (SK)
Cosmic ray impact on extrasolar earth-like planets in close-in habitable zones.
Griessmeier, J-M; Stadelmann, A; Motschmann, U; Belisheva, N K; Lammer, H; Biernat, H K
2005-10-01
Because of their different origins, cosmic rays can be subdivided into galactic cosmic rays and solar/stellar cosmic rays. The flux of cosmic rays to planetary surfaces is mainly determined by two planetary parameters: the atmospheric density and the strength of the internal magnetic moment. If a planet exhibits an extended magnetosphere, its surface will be protected from high-energy cosmic ray particles. We show that close-in extrasolar planets in the habitable zone of M stars are synchronously rotating with their host star because of the tidal interaction. For gravitationally locked planets the rotation period is equal to the orbital period, which is much longer than the rotation period expected for planets not subject to tidal locking. This results in a relatively small magnetic moment. We found that an Earth-like extrasolar planet, tidally locked in an orbit of 0.2 AU around an M star of 0.5 solar masses, has a rotation rate of 2% of that of the Earth. This results in a magnetic moment of less than 15% of the Earth's current magnetic moment. Therefore, close-in extrasolar planets seem not to be protected by extended Earth-like magnetospheres, and cosmic rays can reach almost the whole surface area of the upper atmosphere. Primary cosmic ray particles that interact with the atmosphere generate secondary energetic particles, a so-called cosmic ray shower. Some of the secondary particles can reach the surface of terrestrial planets when the surface pressure of the atmosphere is on the order of 1 bar or less. We propose that, depending on atmospheric pressure, biological systems on the surface of Earth-like extrasolar planets at close-in orbital distances can be strongly influenced by secondary cosmic rays.
Cosmic rays and terrestrial life: A brief review
NASA Astrophysics Data System (ADS)
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.
Space-atmospheric interactions of energetic cosmic rays
NASA Astrophysics Data System (ADS)
Isar, Paula Gina
2015-02-01
Ultra-high energy cosmic rays are the most energetic particles in the Universe of which origin still remain a mystery since a century from their descovery. They are unique messengers coming from far beyond our Milky Way Galaxy, which provides insights into the fundamental matter, energy, space and time. As subatomic particles flying through space to nearly light speed, the ultra-high energy cosmic rays are so rare that they strike the Earth's atmosphere at a rate of up to only one particle per square kilometer per year or century. While the atmosphere is used as a giant calorimeter where cosmic rays induced air showers are initiated and the medium through which Cherenkov or fluorescence light or radio waves propagate, all cosmic ray measurements (performed either from space or ground) rely on an accurate atmospheric monitoring and understanding of atmospheric effects. The interdisciplinary link between Astroparticle Physics and Atmospheric Environment through the ultra-high energy comic rays space - atmospheric interactions, based on the present ground- and future space-based cosmic ray observatories, will be presented.
Diffusion of strongly magnetized cosmic ray particles in a turbulent medium
NASA Technical Reports Server (NTRS)
Ptuskin, V. S.
1985-01-01
Cosmic ray (CR) propagation in a turbulent medium is usually considered in the diffusion approximation. Here, the diffusion equation is obtained for strongly magnetized particles in the general form. The influence of a large-scale random magnetic field on CR propagation in interstellar medium is discussed. Cosmic rays are assumed to propagate in a medium with a regular field H and an ensemble of random MHD waves. The energy density of waves on scales smaller than the free path 1 of CR particles is small. The collision integral of the general form which describes interaction between relativistic particles and waves in the quasilinear approximation is used.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Stroman, Thomas; Pohl, Martin; Niemiec, Jacek
2012-02-10
There is an observational correlation between astrophysical shocks and nonthermal particle distributions extending to high energies. As a first step toward investigating the possible feedback of these particles on the shock at the microscopic level, we perform particle-in-cell (PIC) simulations of a simplified environment consisting of uniform, interpenetrating plasmas, both with and without an additional population of cosmic rays. We vary the relative density of the counterstreaming plasmas, the strength of a homogeneous parallel magnetic field, and the energy density in cosmic rays. We compare the early development of the unstable spectrum for selected configurations without cosmic rays to themore » growth rates predicted from linear theory, for assurance that the system is well represented by the PIC technique. Within the parameter space explored, we do not detect an unambiguous signature of any cosmic-ray-induced effects on the microscopic instabilities that govern the formation of a shock. We demonstrate that an overly coarse distribution of energetic particles can artificially alter the statistical noise that produces the perturbative seeds of instabilities, and that such effects can be mitigated by increasing the density of computational particles.« less
Study of cosmic rays reveals secrets of solar-terrestrial science
NASA Astrophysics Data System (ADS)
Jokipii, J. R.
For many years cosmic rays provided the most important source of energetic particles for studies of subatomic physics. Today, cosmic rays are being studied as a natural phenomenon that can tell us much about both the Earth's environment in space and distant astrophysical processes. Cosmic rays are naturally occurring energetic particles—mainly ions—with kinetic energies extending from just above thermal energies to more than 1020 electron volts (eV). They constantly bombard the Earth from all directions, with more than 1018 particles having energies >1 MeV striking the top of the Earth's atmosphere each second. Figure 1 illustrates the continuous cosmic ray energy spectrum.
Lunar surface cosmic ray experiment S-152, Apollo 16
NASA Technical Reports Server (NTRS)
Fleischer, R. L.; Hart, H. R., Jr.; Carter, M.; Comostock, G. M.; Renshaw, A.; Woods, R. T.
1973-01-01
This investigation was directed at determining the energy spectra and abundances of low energy heavy cosmic rays (0.03 E or = 150 MeV/nucleon). The cosmic rays were detected using plastic and glass particle track detectors. Particles emitted during the 17 April 1972 solar flare dominated the spectra for energies below about 70 MeV/nucleon. Two conclusions emerge from the low energy data: (1) The differential energy spectra for solar particles vary rapidly for energies as low as 0.05 MeV/nucleon for iron-group nuclei. (2) The abundance ratio of heavy elements changes with energy at low energies; heavy elements are enhanced relative to higher elements increasingly as the energy decreases. Galactic particle fluxes recorded within the spacecraft are in agreement with those predicted taking into account solar modulation and spacecraft shielding. The composition of the nuclei at energies above 70 MeV/nucleon imply that these particles originate outside the solar system and hence are galactic cosmic rays.
LORD Space Experiment for Investigation of Ultrahigh Energy Cosmic-ray Particles
NASA Astrophysics Data System (ADS)
Ryabov, V. A.; Gusev, G. A.; Chechin, V. A.
2013-02-01
The problem of detecting cosmic rays and neutrinos of energies above the GZK cutoff is reviewed. Nowadays, it becomes clear that registration of nature's most energetic particles requires approaches based on new principles. First of all, we imply the detection of the coherent Cherenkov radio emission in cascades of ultrahigh-energy particles in radio-transparent natural dense media, i.e., ice shields of Antarctica, mineral salt, and lunar regolith. The Luna-Glob space mission planned for launching in the near future involves the Lunar Orbital Radio Detector (LORD) whose aperture for cosmic rays and neutrinos of energies E >= 1020 eV exceeds all existing ground-based arrays. The feasibility of LORD to detect radio signals from showers initiated by ultrahigh-energy particles interacting with the lunar regolith is examined. The design of the LORD space instrument and its scientific potentialities for registration of low-intense cosmic-ray particle fluxes above the GZK cut-off up to 1025 eV is discussed.
Update on Automated Classification of Interplanetary Dust Particles
NASA Technical Reports Server (NTRS)
Maroger, I.; Lasue, J.; Zolensky, M.
2018-01-01
Every year, the Earth accretes about 40,000 tons of extraterrestrial material less than 1 mm in size on its surface. These dust particles originate from active comets, from impacts between asteroids and may also be coming from interstellar space for the very small particles. Since 1981, NASA Jonhson Space Center (JSC) has been systematically collecting the dust from Earth's strastosphere by airborne collectors and gathered them into "Cosmic Dust Catalogs". In those catalogs, a preliminary analysis of the dust particles based on SEM images, some geological characteristics and X-ray energy-dispersive spectrometry (EDS) composition is compiled. Based on those properties, the IDPs are classified into four main groups: C (Cosmic), TCN (Natural Terrestrial Contaminant), TCA (Artificial Terrestrial Contaminant) and AOS (Aluminium Oxide Sphere). Nevertheless, 20% of those particles remain ambiguously classified. Lasue et al. presented a methodology to help automatically classify the particles published in the catalog 15 based on their EDS spectra and nonlinear multivariate projections (as shown in Fig. 1). This work allowed to relabel 155 particles out of the 467 particles in catalog 15 and reclassify some contaminants as potential cosmic dusts. Further analyses of three such particles indicated their probable cosmic origin. The current work aims to bring complementary information to the automatic classification of IDPs to improve identification criteria.
Charged Particle Environments in Earth's Magnetosphere and their Effects on Space System
NASA Technical Reports Server (NTRS)
Minow, Joseph I.
2009-01-01
This slide presentation reviews information on space radiation environments important to magnetospheric missions including trapped radiation, solar particle events, cosmic rays, and solar winds. It also includes information about ion penetration of the magnetosphere, galactic cosmic rays, solar particle environments, CRRES internal discharge monitor, surface charging and radiation effects.
A beam of particles in ultrahigh-energy cosmic rays?
NASA Astrophysics Data System (ADS)
Krymsky, G. F.; Pravdin, M. I.; Sleptsov, I. E.
2017-11-01
Three particles with energies of 36, 35, and 58 EeV arrived from one sky region were recorded by two EAS arrays during a day. The events are assumed to have been produced by the beam of particles that resulted from the interaction of cosmic rays with a relativistic shock front.
Anisotropy of low-energy Galactic cosmic rays in the outer heliosheath
NASA Astrophysics Data System (ADS)
Zhang, M.; Pogorelov, N.
2017-12-01
Since Voyager 1 crossed the heliopause into the local interstellar medium in August 2012, it has been observing nearly unmodulated low-energy Galactic cosmic rays for over 5 years and 18 AU beyond the heliopause. The angular distribution of these cosmic rays is not isotropic, showing a slight depletion at 90-degree pitch-angle to the magnetic field lines. The anisotropy was interrupted episodically by solar disturbances transmitting through the heliopause into the local interstellar medium of outer heliosheath. These observations indicate the heliosphere still affects cosmic rays in the local interstellar medium. The paper presents a theoretical analysis of the particle transport mechanisms responsible for the observed anisotropy. In order to explain the phenomenon, we argue that cosmic rays of near 90-degree pitch angles do not a quick access to the interstellar cosmic-ray source and in the meantime, they experience some loss in the outer heliosheath. Magnetic field barriers on the both sides of the observer may reduce the access to cosmic ray source, but it still requires that pitch scattering of these particles is very weak in the magnetic field of the outer heliosheath. A possible particle loss mechanism is diffusion into the heliospheric magnetic field where they get modulated by the solar wind plasma. Our model simulation will put constraints on the rates of particle scattering and cross-field diffusion in the interstellar magnetic field of the outer heliosheath.
Global diffusion of cosmic rays in random magnetic fields
NASA Astrophysics Data System (ADS)
Snodin, A. P.; Shukurov, A.; Sarson, G. R.; Bushby, P. J.; Rodrigues, L. F. S.
2016-04-01
The propagation of charged particles, including cosmic rays, in a partially ordered magnetic field is characterized by a diffusion tensor whose components depend on the particle's Larmor radius RL and the degree of order in the magnetic field. Most studies of the particle diffusion presuppose a scale separation between the mean and random magnetic fields (e.g. there being a pronounced minimum in the magnetic power spectrum at intermediate scales). Scale separation is often a good approximation in laboratory plasmas, but not in most astrophysical environments such as the interstellar medium (ISM). Modern simulations of the ISM have numerical resolution of the order of 1 pc, so the Larmor radius of the cosmic rays that dominate in energy density is at least 106 times smaller than the resolved scales. Large-scale simulations of cosmic ray propagation in the ISM thus rely on oversimplified forms of the diffusion tensor. We take the first steps towards a more realistic description of cosmic ray diffusion for such simulations, obtaining direct estimates of the diffusion tensor from test particle simulations in random magnetic fields (with the Larmor radius scale being fully resolved), for a range of particle energies corresponding to 10-2 ≲ RL/lc ≲ 103, where lc is the magnetic correlation length. We obtain explicit expressions for the cosmic ray diffusion tensor for RL/lc ≪ 1, that might be used in a sub-grid model of cosmic ray diffusion. The diffusion coefficients obtained are closely connected with existing transport theories that include the random walk of magnetic lines.
Cosmic rays in the heliosphere
NASA Technical Reports Server (NTRS)
Webber, William R.
1987-01-01
The different types of cosmic ray particles and their role in the heliosphere are briefly described. The rates of various energetic particles were examined as a function of time and used to derive various differential energy gradients. The Pioneer and Voyager cosmic ray observations throughout the heliosphere are indeed giving a perspective on the three-dimensional character and size of the heliosphere. Most clearly the observations are emphasizing the role that transient variations in the outer heliosphere, and most likely the heliospheric boundary shock, play in the 11 year solar cycle modulation of cosmic rays.
Viscosity and inertia in cosmic-ray transport - Effects of an average magnetic field
NASA Technical Reports Server (NTRS)
Williams, L. L.; Jokipii, J. R.
1991-01-01
A generalized transport equation is introduced which describes the transport and propagation of cosmic rays in a magnetized, collisionless medium. The equation is valid if the cosmic-ray distribution function is nearly isotropic in momentum, if the ratio of fluid speed to fluid-flow particle speed is small, and if the ratio of collision time to time for change in the macroscopic flow is small. Five independent cosmic-ray viscosity coefficients are found, and the ralationship of this viscosity to particle orbits in a magnetic field is presented.
Heliospheric influence on the anisotropy of TeV cosmic rays
Zhang, Ming; Zuo, Pingbing; Pogorelov, Nikolai
2014-06-26
This article provides a theory of using Liouville's theorem to map the anisotropy of TeV cosmic rays seen at Earth using the particle distribution function in the local interstellar medium (LISM). The ultimate source of cosmic ray anisotropy is the energy, pitch angle, and spatial dependence of the cosmic ray distribution function in the LISM. Because young nearby cosmic ray sources can make a special contribution to the cosmic ray anisotropy, the anisotropy depends on the source age, distance and magnetic connection, and particle diffusion of these cosmic rays, all of which make the anisotropy sensitive to the particle energy.more » When mapped through the magnetic and electric field of a magnetohydrodynamic model heliosphere, the large-scale dipolar and bidirectional interstellar anisotropy patterns become distorted if they are seen from Earth, resulting in many small structures in the observations. Best fits to cosmic ray anisotropy measurements have allowed us to estimate the particle density gradient and pitch angle anisotropies in the LISM. It is found that the heliotail, hydrogen deflection plane, and the plane perpendicular to the LISM magnetic field play a special role in distorting cosmic ray anisotropy. These features can lead to an accurate determination of the LISM magnetic field direction and polarity. The effects of solar cycle variation, the Sun's coronal magnetic field, and turbulence in the LISM and heliospheric magnetic fields are minor but clearly visible at a level roughly equal to a fraction of the overall anisotropy amplitude. Lastly, the heliospheric influence becomes stronger at lower energies. Below 1 TeV, the anisotropy is dominated by small-scale patterns produced by disturbances in the heliosphere.« less
Heliospheric influence on the anisotropy of TeV cosmic rays
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhang, Ming; Zuo, Pingbing; Pogorelov, Nikolai, E-mail: mzhang@fit.edu
2014-07-20
This paper provides a theory of using Liouville's theorem to map the anisotropy of TeV cosmic rays seen at Earth using the particle distribution function in the local interstellar medium (LISM). The ultimate source of cosmic ray anisotropy is the energy, pitch angle, and spatial dependence of the cosmic ray distribution function in the LISM. Because young nearby cosmic ray sources can make a special contribution to the cosmic ray anisotropy, the anisotropy depends on the source age, distance and magnetic connection, and particle diffusion of these cosmic rays, all of which make the anisotropy sensitive to the particle energy.more » When mapped through the magnetic and electric field of a magnetohydrodynamic model heliosphere, the large-scale dipolar and bidirectional interstellar anisotropy patterns become distorted if they are seen from Earth, resulting in many small structures in the observations. Best fits to cosmic ray anisotropy measurements have allowed us to estimate the particle density gradient and pitch angle anisotropies in the LISM. It is found that the heliotail, hydrogen deflection plane, and the plane perpendicular to the LISM magnetic field play a special role in distorting cosmic ray anisotropy. These features can lead to an accurate determination of the LISM magnetic field direction and polarity. The effects of solar cycle variation, the Sun's coronal magnetic field, and turbulence in the LISM and heliospheric magnetic fields are minor but clearly visible at a level roughly equal to a fraction of the overall anisotropy amplitude. The heliospheric influence becomes stronger at lower energies. Below 1 TeV, the anisotropy is dominated by small-scale patterns produced by disturbances in the heliosphere.« less
Exploring results of the possibility on detecting cosmic ray particles by acoustic way
NASA Technical Reports Server (NTRS)
Jiang, Y.; Yuan, Y.; Li, Y.; Chen, D.; Zheng, R.; Song, J.
1985-01-01
It has been demonstrated experimentally and theoretically that high energy particles produce detectable sounds in water. However, no one has been able to detect an acoustic signal generated by a high energy cosmic ray particle in water. Results show that transient ultrasonic signals in a large lake or reservoir are fairly complex and that the transient signals under water may arise mainly from sound radiation from microbubbles. This field is not explored in detail. Perhaps, the sounds created by cosmic ray particles hide in these ultrasonic signals. In order to develop the technique of acoustic detection, it is most important to make a thorough investigation of these ultrasonic signals in water.
Virtual Energetic Particle Observatory for the Heliospheric Data Environment
NASA Technical Reports Server (NTRS)
Cooper, J. F.; Armstrong, T. P.; Hill, M. E.; Lal, N.; McGuire, R. E.; McKibben, R. B.; Narock, T. W.; Szabo, A.; Tranquille, C.
2007-01-01
The heliosphere is pervaded by interplanetary energetic particles, traditionally also called cosmic rays, from solar, internal heliospheric, and galactic sources. The particles species of interest to heliophysics extend from plasma energies to the GeV energies of galactic cosmic rays still measurably affected by heliospheric modulation and the still higher energies contributing to atmospheric ionization. The NASA and international Heliospheric Network of operational and legacy spacecraft measures interplanetary fluxes of these particles. Spatial coverage extends from the inner heliosphere and geospace to the heliosheath boundary region now being traversed by Voyager 1 and soon by Voyager 2. Science objectives include investigation of solar flare and coronal mass ejection events, acceleration and transport of interplanetary particles within the inner heliosphere, cosmic ray interactions with planetary surfaces and atmospheres, sources of suprathermal and anomalous cosmic ray ions in the outer heliosphere, and solar cycle modulation of galactic cosmic rays. The Virtual Energetic Particle Observatory (VEPO) will improve access and usability of selected spacecraft and sub-orbital NASA heliospheric energetic particle data sets as a newly approved effort within the evolving heliophysics virtual observatory environment. In this presentation, we will describe current VEPO science requirements, our initial priorities and an overview of our strategy to implement VEPO rapidly and at minimal cost by working within the high-level framework of the Virtual Heliospheric Observatory (VHO). VEPO will also leverage existing data services of NASA's Space Physics Data Facility and other existing capabilities of the U.S. and international heliospheric research communities.
Atmospheric cosmic rays and solar energetic particles at aircraft altitudes.
O'Brien, K; Friedberg, W; Sauer, H H; Smart, D F
1996-01-01
Galactic cosmic rays, which are thought to be produced and accelerated by a variety of mechanisms in the Milky Way galaxy, interact with the solar wind, the earth's magnetic field, and its atmosphere to produce hadron, lepton, and photon fields at aircraft altitudes that are quite unlike anything produced in the laboratory. The energy spectra of these secondary particles extend from the lowest possible energy to energies over an EeV. In addition to cosmic rays, energetic particles, generated on the sun by solar flares or coronal mass ejections, bombard the earth from time to time. These particles, while less energetic than cosmic rays, also produce radiation fields at aircraft altitudes which have qualitatively the same properties as cosmic rays. The authors have calculated atmospheric cosmic-ray angular fluxes, spectra, scalar fluxes, and ionization, and compared them with experimental data. Agreement with these data is seen to be good. These data have been used to calculate equivalent doses in a simplified human phantom at aircraft altitudes and the estimated health risks to aircraft crews. The authors have also calculated the radiation doses from several large solar energetic particle events (known as GLEs, or Ground Level Events), which took place in 1989, including the very large event known as GLE 42, which took place on September 29th and 30th of that year. The spectra incident on the atmosphere were determined assuming diffusive shock theory. Unfortunately, there are essentially no experimental data with which to compare these calculations.
NASA Technical Reports Server (NTRS)
Atwell, William; Koontz, Steve; Normand, Eugene
2012-01-01
In this paper we review the discovery of cosmic ray effects on the performance and reliability of microelectronic systems as well as on human health and safety, as well as the development of the engineering and health science tools used to evaluate and mitigate cosmic ray effects in earth surface, atmospheric flight, and space flight environments. Three twentieth century technological developments, 1) high altitude commercial and military aircraft; 2) manned and unmanned spacecraft; and 3) increasingly complex and sensitive solid state micro-electronics systems, have driven an ongoing evolution of basic cosmic ray science into a set of practical engineering tools (e.g. ground based test methods as well as high energy particle transport and reaction codes) needed to design, test, and verify the safety and reliability of modern complex electronic systems as well as effects on human health and safety. The effects of primary cosmic ray particles, and secondary particle showers produced by nuclear reactions with spacecraft materials, can determine the design and verification processes (as well as the total dollar cost) for manned and unmanned spacecraft avionics systems. Similar considerations apply to commercial and military aircraft operating at high latitudes and altitudes near the atmospheric Pfotzer maximum. Even ground based computational and controls systems can be negatively affected by secondary particle showers at the Earth's surface, especially if the net target area of the sensitive electronic system components is large. Accumulation of both primary cosmic ray and secondary cosmic ray induced particle shower radiation dose is an important health and safety consideration for commercial or military air crews operating at high altitude/latitude and is also one of the most important factors presently limiting manned space flight operations beyond low-Earth orbit (LEO).
The microphysics and macrophysics of cosmic rays
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zweibel, Ellen G.
2013-05-15
This review paper commemorates a century of cosmic ray research, with emphasis on the plasma physics aspects. Cosmic rays comprise only ∼10{sup −9} of interstellar particles by number, but collectively their energy density is about equal to that of the thermal particles. They are confined by the Galactic magnetic field and well scattered by small scale magnetic fluctuations, which couple them to the local rest frame of the thermal fluid. Scattering isotropizes the cosmic rays and allows them to exchange momentum and energy with the background medium. I will review a theory for how the fluctuations which scatter the cosmicmore » rays can be generated by the cosmic rays themselves through a microinstability excited by their streaming. A quasilinear treatment of the cosmic ray–wave interaction then leads to a fluid model of cosmic rays with both advection and diffusion by the background medium and momentum and energy deposition by the cosmic rays. This fluid model admits cosmic ray modified shocks, large scale cosmic ray driven instabilities, cosmic ray heating of the thermal gas, and cosmic ray driven galactic winds. If the fluctuations were extrinsic turbulence driven by some other mechanism, the cosmic ray background coupling would be entirely different. Which picture holds depends largely on the nature of turbulence in the background medium.« less
Calculations of cosmic-ray helium transport in shielding materials
NASA Technical Reports Server (NTRS)
Cucinotta, Francis A.
1993-01-01
The transport of galactic cosmic-ray helium nuclei and their secondaries through bulk shielding is considered using the straight-ahead approximation to the Boltzmann equation. A data base for nuclear interaction cross sections and secondary particle energy spectra for high-energy light-ion breakup is presented. The importance of the light ions H-2, H-3, and He-3 for cosmic-ray risk estimation is discussed, and the estimates of the fractional contribution to the neutron flux from helium interactions compared with other particle interactions are presented using a 1977 solar minimum cosmic-ray spectrum.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Collica, Laura
The Pierre Auger Observatory (Auger) in Argentina studies Ultra High Energy Cosmic Rays (UHECRs) physics. The flux of cosmic rays at these energies (above 1018 eV) is very low (less than 100 particle/km2-year) and UHECR properties must be inferred from the measurements of the secondary particles that the cosmic ray primary produces in the atmosphere. These particles cascades are called Extensive Air Showers (EAS) and can be studied at ground by deploying detectors covering large areas. The EAS physics is complex, and the properties of secondary particles depend strongly on the first interaction, which takes place at an energy beyondmore » the ones reached at accelerators. As a consequence, the analysis of UHECRs is subject to large uncertainties and hence many of their properties, in particular their composition, are still unclear. Two complementary techniques are used at Auger to detect EAS initiated by UHE- CRs: a 3000 km2 surface detector (SD) array of water Cherenkov tanks which samples particles at ground level and fluorescence detectors (FD) which collect the ultraviolet light emitted by the de-excitation of nitrogen nuclei in the atmosphere, and can operate only in clear, moonless nights. Auger is the largest cosmic rays detector ever built and it provides high-quality data together with unprecedented statistics. The main goal of this thesis is the measurement of UHECR mass composition using data from the SD of the Pierre Auger Observatory. Measuring the cosmic ray composition at the highest energies is of fundamental importance from the astrophysical point of view, since it could discriminate between different scenarios of origin and propagation of cosmic rays. Moreover, mass composition studies are of utmost importance for particle physics. As a matter of fact, knowing the composition helps in exploring the hadronic interactions at ultra-high energies, inaccessible to present accelerator experiments.« less
Ultrahigh energy cosmic rays from nearby starburst galaxies
NASA Astrophysics Data System (ADS)
Attallah, Reda; Bouchachi, Dallel
2018-04-01
Ultrahigh energy cosmic rays are the most energetic of any subatomic particles ever observed in nature. The quest for their mysterious origin is currently a major scientific challenge. Here we explore the possibility that these particles originate from nearby starburst galaxies, a scenario that matches the recent observation by the Telescope Array experiment of a cosmic-ray hotspot above 57 EeV not far from the direction of the starburst galaxy M82. Specifically, we study the stochastic propagation in space of ultrahigh energy cosmic rays through the state-of-the-art simulation framework CRPropa 3, taking into account all relevant particle interactions as well as deflections by the intervening magnetic fields. To ensure a comprehensive understanding of this model, we consider the energy spectrum, the cosmogenic neutrinos and gamma rays, and the distribution of arrival directions. The starburst galaxy scenario reproduces well observations from both the Telescope Array and Pierre Auger Observatories, making it very attractive for explaining the origin of cosmic rays at the highest energies.
Ultrahigh energy cosmic rays from nearby starburst galaxies
NASA Astrophysics Data System (ADS)
Attallah, Reda; Bouchachi, Dallel
2018-07-01
Ultrahigh energy cosmic rays are the most energetic of any subatomic particles ever observed in nature. The quest for their mysterious origin is currently a major scientific challenge. Here we explore the possibility that these particles originate from nearby starburst galaxies, a scenario that matches the recent observation by the Telescope Array experiment of a cosmic ray hotspot above 57 EeV not far from the direction of the starburst galaxy M82. Specifically, we study the stochastic propagation in space of ultrahigh ENERGY cosmic rays through the state-of-the-art simulation framework CRPROPA 3, taking into account all relevant particle interactions as well as deflections by the intervening magnetic fields. To ensure a comprehensive understanding of this model, we consider the energy spectrum, the cosmogenic neutrinos and gamma rays, and the distribution of arrival directions. The starburst galaxy scenario reproduces well observations from both the Telescope Array and Pierre Auger Observatories, making it very attractive for explaining the origin of cosmic rays at the highest energies.
Progress report on the Heavy Ions in Space (HIIS) experiment
NASA Technical Reports Server (NTRS)
Adams, James H., Jr.; Beahm, Lorraine P.; Boberg, Paul R.; Tylka, Allan J.
1993-01-01
One of the objectives of the Heavy Ions In Space (HIIS) experiment is to investigate heavy ions which appear at Long Duration Exposure Facility (LDEF) below the geomagnetic cutoff for fully-ionized galactic cosmic rays. Possible sources of such 'below-cutoff' particles are partially-ionized solar energetic particles, the anomalous component of cosmic rays, and magnetospherically-trapped particles. In recent years, there have also been reports of below-cutoff ions which do not appear to be from any known source. Although most of these observations are based on only a handful of ions, they have led to speculation about 'partially-ionized galactic cosmic rays' and 'near-by cosmic ray sources'. The collecting power of HIIS is order of magnitude larger than that of the instruments which reported these results, so HIIS should be able to confirm these observations and perhaps discover the source of these particles. Preliminary results on below-cutoff heavy-ions are reported. Observations to possible known sources of such ions are compared. A second objective of the HIIS experiment is to measure the elemental composition of ultraheavy galactic cosmic rays, beginning in the tin-barium region of the periodic table. A report on the status of this analysis is presented.
Mishev, A L
2016-03-01
A numerical model for assessment of the effective dose due to secondary cosmic ray particles of galactic origin at high mountain altitude of about 3000 m above the sea level is presented. The model is based on a newly numerically computed effective dose yield function considering realistic propagation of cosmic rays in the Earth magnetosphere and atmosphere. The yield function is computed using a full Monte Carlo simulation of the atmospheric cascade induced by primary protons and α- particles and subsequent conversion of secondary particle fluence (neutrons, protons, gammas, electrons, positrons, muons and charged pions) to effective dose. A lookup table of the newly computed effective dose yield function is provided. The model is compared with several measurements. The comparison of model simulations with measured spectral energy distributions of secondary cosmic ray neutrons at high mountain altitude shows good consistency. Results from measurements of radiation environment at high mountain station--Basic Environmental Observatory Moussala (42.11 N, 23.35 E, 2925 m a.s.l.) are also shown, specifically the contribution of secondary cosmic ray neutrons. A good agreement with the model is demonstrated. Copyright © 2015 Elsevier Ltd. All rights reserved.
NASA Technical Reports Server (NTRS)
Chuang, L. S.; Chan, K. W.; Wada, M.
1985-01-01
Cosmic ray particles at sea level penetrate a thick layer of dense medium without appreciable interaction. These penetrating particles are identified with muons. The only appreciable interaction of muons are by knock on processes. A muon may have single, double or any number of knock on with atoms of the material so that one, two, three or more particles will come out from the medium in which the knock on processes occur. The probability of multiparticle production is expected to decrease with the increase of multiplicity. Measurements of the single, double, and triple particles generated in a dense medium (Fe and Al) by sea level cosmic rays at 22.42 N. Lat. and 114.20 E. Long. (Hong Kong) are presented using a detector composed of two plastic scintillators connected in coincidence.
Cosmic Rays in Intermittent Magnetic Fields
DOE Office of Scientific and Technical Information (OSTI.GOV)
Shukurov, Anvar; Seta, Amit; Bushby, Paul J.
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 particlemore » energies. We demonstrate that the results can be interpreted in terms of a correlated random walk.« less
High energy interactions of cosmic ray particles
NASA Technical Reports Server (NTRS)
Jones, L. W.
1986-01-01
The highlights of seven sessions of the Conference dealing with high energy interactions of cosmic rays are discussed. High energy cross section measurements; particle production-models of experiments; nuclei and nuclear matter; nucleus-nucleus collision; searches for magnetic monopoles; and studies of nucleon decay are covered.
On the maximum energy of shock-accelerated cosmic rays at ultra-relativistic shocks
NASA Astrophysics Data System (ADS)
Reville, B.; Bell, A. R.
2014-04-01
The maximum energy to which cosmic rays can be accelerated at weakly magnetised ultra-relativistic shocks is investigated. We demonstrate that for such shocks, in which the scattering of energetic particles is mediated exclusively by ion skin-depth scale structures, as might be expected for a Weibel-mediated shock, there is an intrinsic limit on the maximum energy to which particles can be accelerated. This maximum energy is determined from the requirement that particles must be isotropized in the downstream plasma frame before the mean field transports them far downstream, and falls considerably short of what is required to produce ultra-high-energy cosmic rays. To circumvent this limit, a highly disorganized field is required on larger scales. The growth of cosmic ray-induced instabilities on wavelengths much longer than the ion-plasma skin depth, both upstream and downstream of the shock, is considered. While these instabilities may play an important role in magnetic field amplification at relativistic shocks, on scales comparable to the gyroradius of the most energetic particles, the calculated growth rates have insufficient time to modify the scattering. Since strong modification is a necessary condition for particles in the downstream region to re-cross the shock, in the absence of an alternative scattering mechanism, these results imply that acceleration to higher energies is ruled out. If weakly magnetized ultra-relativistic shocks are disfavoured as high-energy particle accelerators in general, the search for potential sources of ultra-high-energy cosmic rays can be narrowed.
NASA Technical Reports Server (NTRS)
Dragovitsch, P.; Englert, P.
1985-01-01
Through the interaction of galactic cosmic particle radiation (GCR) a wide variety of cosmogenic nuclides is produced in meteorites. They provide historical information about the cosmic radiation and the bombarded meteorites. An important way to understand the production mechanisms of cosmogenic nuclides in meteorites is to gather information about the depth and size dependence of the build-up of Galactic Rays Cosmic-secondary particles within meteorites of different sizes and chemical compositions. Simulation experiments with meteorite models offer an alternative to direct observation providing a data basis to describe the development and action of the secondary cascade induced by the GCR in meteorites.
Limits on deeply penetrating particles in the 10(17) eV cosmic ray flux
NASA Technical Reports Server (NTRS)
Baltrusaitis, R. M.; Cassiday, G. L.; Cooper, R.; Elbert, J. W.; Gerhardy, J. W.; Loh, P. R.; Mizumoto, Y.; Sokolsky, P.; Sommers, P.; Steck, D.
1985-01-01
Deeply penetrating particles in the 10 to the 17th power eV cosmic ray flux were investigated. No such events were found in 8.2 x 10 to the 6th power sec of running time. Limits were set on the following: quark-matter in the primary cosmic ray flux; long-lived, weakly interacting particles produced in p-air collisions; the astrophysical neutrino flux. In particular, the neutrino flux limit at 10 to the 17th power eV implies that z, the red shift of maximum activity is 10 in the model of Hill and Schramm.
Do some of the sub-micrometer cosmic dust particles come from the sun.
NASA Technical Reports Server (NTRS)
Hemenway, C. L.; Erkes, J. W.; Greenberg, J. M.; Hallgren, D. S.; Schmalberger, D. C.
1973-01-01
Studies of cosmic dust particles collected at altitudes of 80 to 120 km over White Sands, New Mexico, and at times of noctilucent clouds over Kiruna, Sweden, indicate that an anomalously high atomic weight contribution is present within those particles collected at Kiruna. The elements observed are inconsistent with an origin due to atomic bomb fallout, meteoroidal crumbling, lunar ejecta, or comets. Many of these heavy elements may be stable in particulate form at the relatively high temperatures found in the coolest regions of the solar atmosphere. Some implications of the sun as the source of a significant component of cosmic dust are discussed.
Dosimeter design, construction, and implantation. [for recording HZE cosmic particle tracks
NASA Technical Reports Server (NTRS)
Winter, D. L.; Suri, K.; Durso, J. A.; Cota, F. L.; Ashley, W. W.; Binnard, R. M.; Haymaker, W.; Benton, E. V.; Cruty, M. R.; Zeman, W.
1975-01-01
To detect the passage of cosmic ray particles through the heads of the pocket mice during the Apollo XVII flight, a 'monitor' (dosimeter) composed of plastics was prepared and implanted under the scalp. The monitor was mounted on a platform, the undersurface of which fitted the contour of the skull. Numerous tests were run to assure that the presence of the monitor assembly beneath the scalp would be compatible with the well-being of the mice and that the capacity of the monitor to detect the traversal of cosmic ray particles would be preserved over the several weeks during which it would remain under the scalp.
New fermionic dark matters, extended Standard Model and cosmic rays
NASA Astrophysics Data System (ADS)
Hwang, Jae-Kwang
2017-08-01
Three generations of leptons and quarks correspond to the lepton charges (LCs) in this work. Then, the leptons have the electric charges (ECs) and LCs. The quarks have the ECs, LCs and color charges (CCs). Three heavy leptons and three heavy quarks are introduced to make the missing third flavor of EC. Then the three new particles which have the ECs are proposed as the bastons (dark matters) with the rest masses of 26.121 eV/c2, 42.7 GeV/c2 and 1.9 × 1015 eV/c2. These new particles are applied to explain the origins of the astrophysical observations like the ultra-high energy cosmic rays and supernova 1987A anti-neutrino data. It is concluded that the 3.5 keV X-ray peak observed from the cosmic X-ray background spectra is originated not from the pair annihilations of the dark matters but from the X-ray emission of the Q1 baryon atoms which are similar in the atomic structure to the hydrogen atom. The presence of the 3.5 keV cosmic X-ray supports the presence of the Q1 quark with the EC of -4/3. New particles can be indirectly seen from the astrophysical observations like the cosmic ray and cosmic gamma ray. In this work, the systematic quantized charges of EC, LC and CC for the elementary particles are used to consistently explain the decay and reaction schemes of the elementary particles. Also, the strong, weak and dark matter forces are consistently explained.
Cosmic ray production in modified gravity
NASA Astrophysics Data System (ADS)
Arbuzova, E. V.; Dolgov, A. D.; Reverberi, L.
2018-06-01
This paper is a reply to the criticism of our work on particle production in modified gravity by Gorbunov and Tokareva. We show that their arguments against efficient particle production are invalid. F( R) theories can lead to an efficient generation of high energy cosmic rays in contracting systems.
Does electromagnetic radiation accelerate galactic cosmic rays
NASA Technical Reports Server (NTRS)
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.
High-Energy Cosmic Rays from Supernovae
NASA Astrophysics Data System (ADS)
Morlino, Giovanni
Cosmic rays are charged relativistic particles that reach the Earth with extremely high energies, providing striking evidence of the existence of effective accelerators in the Universe. Below an energy around ˜ 1017 eV, cosmic rays are believed to be produced in the Milky Way, while above that energy, their origin is probably extragalactic. In the early 1930s, supernovae were already identified as possible sources for the galactic component of cosmic rays. After the 1970s this idea has gained more and more credibility, thanks to the development of the diffusive shock acceleration theory, which provides a robust theoretical framework for particle energization in astrophysical environments. Afterward, mostly in recent years, much observational evidence has been gathered in support of this framework, converting a speculative idea in a real paradigm. In this chapter the basic pillars of this paradigm will be illustrated. This includes the acceleration mechanism, the nonlinear effects produced by accelerated particles onto the shock dynamics needed to reach the highest energies, the escape process from the sources, and the transportation of cosmic rays through the Galaxy. The theoretical picture will be corroborated by discussing several observations which support the idea that supernova remnants are effective cosmic ray factories.
Cosmic-Ray Source Composition Determined from ACE
NASA Technical Reports Server (NTRS)
Wiedenbeck, M.
2000-01-01
The cosmic rays arriving at Earth comprise a mix of material produced by stellar sources and ejected into the interstellar medium (primary cosmic rays) and particles produced by fragmentation of heavier nuclei during transport through the Galaxy.
High energy physics in cosmic rays
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jones, Lawrence W.
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 raymore » 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.« less
Buitink, S; Corstanje, A; Falcke, H; Hörandel, J R; Huege, T; Nelles, A; Rachen, J P; Rossetto, L; Schellart, P; Scholten, O; ter Veen, S; Thoudam, S; Trinh, T N G; Anderson, J; Asgekar, A; Avruch, I M; Bell, M E; Bentum, M J; Bernardi, G; Best, P; Bonafede, A; Breitling, F; Broderick, J W; Brouw, W N; Brüggen, M; Butcher, H R; Carbone, D; Ciardi, B; Conway, J E; de Gasperin, F; de Geus, E; Deller, A; Dettmar, R-J; van Diepen, G; Duscha, S; Eislöffel, J; Engels, D; Enriquez, J E; Fallows, R A; Fender, R; Ferrari, C; Frieswijk, W; Garrett, M A; Grießmeier, J M; Gunst, A W; van Haarlem, M P; Hassall, T E; Heald, G; Hessels, J W T; Hoeft, M; Horneffer, A; Iacobelli, M; Intema, H; Juette, E; Karastergiou, A; Kondratiev, V I; Kramer, M; Kuniyoshi, M; Kuper, G; van Leeuwen, J; Loose, G M; Maat, P; Mann, G; Markoff, S; McFadden, R; McKay-Bukowski, D; McKean, J P; Mevius, M; Mulcahy, D D; Munk, H; Norden, M J; Orru, E; Paas, H; Pandey-Pommier, M; Pandey, V N; Pietka, M; Pizzo, R; Polatidis, A G; Reich, W; Röttgering, H J A; Scaife, A M M; Schwarz, D J; Serylak, M; Sluman, J; Smirnov, O; Stappers, B W; Steinmetz, M; Stewart, A; Swinbank, J; Tagger, M; Tang, Y; Tasse, C; Toribio, M C; Vermeulen, R; Vocks, C; Vogt, C; van Weeren, R J; Wijers, R A M J; Wijnholds, S J; Wise, M W; Wucknitz, O; Yatawatta, S; Zarka, P; Zensus, J A
2016-03-03
Cosmic rays are the highest-energy particles found in nature. Measurements of the mass composition of cosmic rays with energies of 10(17)-10(18) electronvolts are essential to understanding whether they have galactic or extragalactic sources. It has also been proposed that the astrophysical neutrino signal comes from accelerators capable of producing cosmic rays of these energies. Cosmic rays initiate air showers--cascades of secondary particles in the atmosphere-and their masses can be inferred from measurements of the atmospheric depth of the shower maximum (Xmax; the depth of the air shower when it contains the most particles) or of the composition of shower particles reaching the ground. Current measurements have either high uncertainty, or a low duty cycle and a high energy threshold. Radio detection of cosmic rays is a rapidly developing technique for determining Xmax (refs 10, 11) with a duty cycle of, in principle, nearly 100 per cent. The radiation is generated by the separation of relativistic electrons and positrons in the geomagnetic field and a negative charge excess in the shower front. Here we report radio measurements of Xmax with a mean uncertainty of 16 grams per square centimetre for air showers initiated by cosmic rays with energies of 10(17)-10(17.5) electronvolts. This high resolution in Xmax enables us to determine the mass spectrum of the cosmic rays: we find a mixed composition, with a light-mass fraction (protons and helium nuclei) of about 80 per cent. Unless, contrary to current expectations, the extragalactic component of cosmic rays contributes substantially to the total flux below 10(17.5) electronvolts, our measurements indicate the existence of an additional galactic component, to account for the light composition that we measured in the 10(17)-10(17.5) electronvolt range.
Super-alfvenic propagation of cosmic rays: The role of streaming modes
NASA Technical Reports Server (NTRS)
Morrison, P. J.; Scott, J. S.; Holman, G. D.; Ionson, J. A.
1980-01-01
Numerous cosmic ray propagation and acceleration problems require knowledge of the propagation speed of relativistic particles through an ambient plasma. Previous calculations indicated that self-generated turbulence scatters relativistic particles and reduces their bulk streaming velocity to the Alfven speed. This result was incorporated into all currently prominent theories of cosmic ray acceleration and propagation. It is demonstrated that super-Alfvenic propagation is indeed possible for a wide range of physical parameters. This fact dramatically affects the predictions of these models.
Re-Analysis of Data on the Space Radiation Environment above South-East Asia
1989-11-01
the cosmic ray flux with geomagnetic latitude, and also show expected increases due to the South Atlantic Anomaly (SAA) and outer belt electrons. How...TECHNIQUES USED 8 3.1 Orbital analysis 8 3.2 Analysis of cosmic ray effects 9 3.3 Analysis of trapped particle effects 11 3.4 Geomagnetic and...magnetospheric activity 12 4 UNCERTAINTIES AND SOURCES OF ERROR 13 4.1 Orbital analysis 13 4.2 Analysis of cosmic ray effects 13 4.3 Analysis of trapped particle
Placers of cosmic dust in the blue ice lakes of Greenland
NASA Technical Reports Server (NTRS)
Maurette, M.; Hammer, C.; Reeh, N.; Brownlee, D. E.; Thomsen, H. H.
1986-01-01
A concentration process occurring in the melt zone of the Greenland ice cap has produced the richest known deposit of cosmic dust on the surface of the earth. Extraterrestrial particles collected from this region are well preserved and are collectable in large quantities. The collected particles are generally identical to cosmic spheres found on the ocean floor, but a pure glass type was discovered that has not been seen in deep-sea samples. Iron-rich spheres are conspicuously rare in the collected material.
NASA Technical Reports Server (NTRS)
Curtis, Stanley B.
1993-01-01
The possible health risks posed by Galactic cosmic rays, especially the possible heightened cancer risk, are examined. The results of the Biostack studies of the biological effects of high-energy cosmic rays are discussed. The biological mechanisms involved in possible harm due to cosmic rays are considered.
Diffuse Galactic gamma rays from shock-accelerated cosmic rays.
Dermer, Charles D
2012-08-31
A shock-accelerated particle flux is proportional to p(-s), where p is the particle momentum, follows from simple theoretical considerations of cosmic-ray acceleration at nonrelativistic shocks followed by rigidity-dependent escape into the Galactic halo. A flux of shock-accelerated cosmic-ray protons with s≈2.8 provides an adequate fit to the Fermi Large Area Telescope γ-ray emission spectra of high-latitude and molecular cloud gas when uncertainties in nuclear production models are considered. A break in the spectrum of cosmic-ray protons claimed by Neronov, Semikoz, and Taylor [Phys. Rev. Lett. 108, 051105 (2012)] when fitting the γ-ray spectra of high-latitude molecular clouds is a consequence of using a cosmic-ray proton flux described by a power law in kinetic energy.
Origin and transport of high energy particles in the galaxy
NASA Technical Reports Server (NTRS)
Wefel, John P.
1987-01-01
The origin, confinement, and transport of cosmic ray nuclei in the galaxy was studied. The work involves interpretations of the existing cosmic ray physics database derived from both balloon and satellite measurements, combined with an effort directed towards defining the next generation of instruments for the study of cosmic radiation. The shape and the energy dependence of the cosmic ray pathlength distribution in the galaxy was studied, demonstrating that the leaky box model is not a good representation of the detailed particle transport over the energy range covered by the database. Alternative confinement methods were investigated, analyzing the confinement lifetime in these models based upon the available data for radioactive secondary isotopes. The source abundances of several isotopes were studied using compiled nuclear physics data and the detailed transport calculations. The effects of distributed particle acceleration on the secondary to primary ratios were investigated.
A deep learning-based reconstruction of cosmic ray-induced air showers
NASA Astrophysics Data System (ADS)
Erdmann, M.; Glombitza, J.; Walz, D.
2018-01-01
We describe a method of reconstructing air showers induced by cosmic rays using deep learning techniques. We simulate an observatory consisting of ground-based particle detectors with fixed locations on a regular grid. The detector's responses to traversing shower particles are signal amplitudes as a function of time, which provide information on transverse and longitudinal shower properties. In order to take advantage of convolutional network techniques specialized in local pattern recognition, we convert all information to the image-like grid of the detectors. In this way, multiple features, such as arrival times of the first particles and optimized characterizations of time traces, are processed by the network. The reconstruction quality of the cosmic ray arrival direction turns out to be competitive with an analytic reconstruction algorithm. The reconstructed shower direction, energy and shower depth show the expected improvement in resolution for higher cosmic ray energy.
Research in cosmic and gamma ray astrophysics: Cosmic physics portion
NASA Technical Reports Server (NTRS)
Stone, Edward C.; Mewaldt, Richard A.; Schindler, Stephen
1993-01-01
Research in particle astrophysics at the Space Radiation Laboratory (SRL) of the California Institute of Technology is supported under NASA Grant NAGW-1919. A three-year proposal for continuation of support was submitted a year ago and put into effect 1 October 1992. This report is the combined progress report and continuation application called for under the Federal Demonstration Project. Gamma-ray Astrophysics at SRL is separately supported under NAGW-1919 and will be separately summarized and proposed. This report will document progress and plans for our particle spectroscopy activities and for related data analysis, calibration, and community service activities. A bibliography and a budget will be attached as appendices. The Caltech SRL research program includes a heavy emphasis on elemental and isotopic spectroscopy of energetic particles in the cosmic radiation; in solar, interplanetary, and anomalous 'cosmic' radiation; and in planetary magnetospheres as discussed.
Nymmik, R A
1999-10-01
A wide range of the galactic cosmic ray and SEP event flux simulation problems for the near-Earth satellite and manned spacecraft orbits and for the interplanetary mission trajectories are discussed. The models of the galactic cosmic ray and SEP events in the Earth orbit beyond the Earth's magnetosphere are used as a basis. The particle fluxes in the near-Earth orbits should be calculated using the transmission functions. To calculate the functions, the dependences of the cutoff rigidities on the magnetic disturbance level and on magnetic local time have to be known. In the case of space flights towards the Sun and to the boundary of the solar system, particular attention is paid to the changes in the SEP event occurrence frequency and size. The particle flux gradients are applied in this case to galactic cosmic ray fluxes.
Charge 4/3 leptons in cosmic rays
NASA Technical Reports Server (NTRS)
Wada, T.; Yamashita, Y.; Imaeda, K.; Yamamoto, I.
1985-01-01
A cosmic ray counter telescope has been operated at zenith angles of 0, 40, 44, and 60 degs in order to look for charge 4/3 particles. A few million clean single cosmic rays of each zenith angle are analyzed.
NASA Astrophysics Data System (ADS)
Hill, M. E.; Kollmann, P.; McNutt, R. L., Jr.; Stern, A.; Weaver, H. A., Jr.; Young, L. A.; Olkin, C.; Spencer, J. R.
2017-12-01
During the period from January 2012 to December 2017 the New Horizons spacecraft traveled from 22 to 41 AU from the Sun, making nearly continuous interplanetary plasma and particle measurements utilizing the SWAP and PEPSSI instruments. We report on newly extended measurements from PEPSSI (Pluto Energetic Particle Spectrometer Science Investigation) that now bring together suprathermal particles above 2 keV/nuc (including interstellar pickup ions), energetic particles with H, He, and O composition from 30 keV to 1 MeV, and cosmic rays above 65 MeV (with effective count-rate-limited upper energy of 1 GeV). Such a wide energy range allows us to look at the solar wind structures passing over the spacecraft, the energetic particles that are often accelerated by these structures, and the suppression of cosmic rays resulting from the increased turbulence inhibiting cosmic ray transport to the spacecraft position (i.e., Forbush decreases). This broad perspective provides simultaneous, previously unattainable diagnostics of outer heliospheric particle dynamics and acceleration. Besides the benefit of being recent, in-ecliptic measurements, unlike the historic Voyager 1 and 2 spacecraft, these PEPSSI observations are also totally unique in the suprathermal range; in this region only PEPSSI can span the suprathermal range, detecting a population that is a linchpin to understanding the outer heliosphere.
An alternative interpretation for cosmic ray peaks
Kim, Doojin; Park, Jong -Chul
2015-10-03
We propose an alternative mechanism based upon dark matter (DM) interpretation for anomalous peak signatures in cosmic ray measurements, assuming an extended dark sector with two DM species. This is contrasted with previous effort to explain various line-like cosmic-ray excesses in the context of DM models where the relevant DM candidate directly annihilates into Standard Model (SM) particles. The heavier DM is assumed to annihilate to an on-shell intermediate state. As the simplest choice, it decays directly into the lighter DM along with an unstable particle which in turn decays to a pair of SM states corresponding to the interestingmore » cosmic anomaly. We show that a sharp continuum energy peak can be readily generated under the proposed DM scenario, depending on dark sector particle mass spectra. Remarkably, such a peak is robustly identified as half the mass of the unstable particle. Furthermore, other underlying mass parameters are analytically related to the shape of energy spectrum. We apply this idea to the two well-known line excesses in the cosmic photon spectrum: 130 GeV γ-ray line and 3.5 keV X-ray line. As a result, each observed peak spectrum is well-reproduced by theoretical expectation predicated upon our suggested mechanism, and moreover, our resulting best fits provide rather improved χ 2 values.« less
Turbulence, Magnetic Reconnection in Turbulent Fluids and Energetic Particle Acceleration
NASA Astrophysics Data System (ADS)
Lazarian, A.; Vlahos, L.; Kowal, G.; Yan, H.; Beresnyak, A.; de Gouveia Dal Pino, E. M.
2012-11-01
Turbulence is ubiquitous in astrophysics. It radically changes many astrophysical phenomena, in particular, the propagation and acceleration of cosmic rays. We present the modern understanding of compressible magnetohydrodynamic (MHD) turbulence, in particular its decomposition into Alfvén, slow and fast modes, discuss the density structure of turbulent subsonic and supersonic media, as well as other relevant regimes of astrophysical turbulence. All this information is essential for understanding the energetic particle acceleration that we discuss further in the review. For instance, we show how fast and slow modes accelerate energetic particles through the second order Fermi acceleration, while density fluctuations generate magnetic fields in pre-shock regions enabling the first order Fermi acceleration of high energy cosmic rays. Very importantly, however, the first order Fermi cosmic ray acceleration is also possible in sites of magnetic reconnection. In the presence of turbulence this reconnection gets fast and we present numerical evidence supporting the predictions of the Lazarian and Vishniac (Astrophys. J. 517:700-718, 1999) model of fast reconnection. The efficiency of this process suggests that magnetic reconnection can release substantial amounts of energy in short periods of time. As the particle tracing numerical simulations show that the particles can be efficiently accelerated during the reconnection, we argue that the process of magnetic reconnection may be much more important for particle acceleration than it is currently accepted. In particular, we discuss the acceleration arising from reconnection as a possible origin of the anomalous cosmic rays measured by Voyagers as well as the origin cosmic ray excess in the direction of Heliotail.
Cosmic Ray research in Armenia
NASA Astrophysics Data System (ADS)
Chilingarian, A.; Mirzoyan, R.; Zazyan, M.
2009-11-01
Cosmic Ray research on Mt. Aragats began in 1934 with the measurements of East-West anisotropy by the group from Leningrad Physics-Technical Institute and Norair Kocharian from Yerevan State University. Stimulated by the results of their experiments in 1942 Artem and Abraham Alikhanyan brothers organized a scientific expedition to Aragats. Since that time physicists were studying Cosmic Ray fluxes on Mt. Aragats with various particle detectors: mass spectrometers, calorimeters, transition radiation detectors, and huge particle detector arrays detecting protons and nuclei accelerated in most violent explosions in Galaxy. Latest activities at Mt. Aragats include Space Weather research with networks of particle detectors located in Armenia and abroad, and detectors of Space Education center in Yerevan.
NASA Technical Reports Server (NTRS)
Gronoff, G.; Mertens, C.; Lilensten, J.; Desorgher, L.; Fluckiger, E.; Velinov, P.
2011-01-01
Context. The Cassini-Huygens mission has revealed the importance of particle precipitation in the atmosphere of Titan thanks to in-situ measurements. These ionizing particles (electrons, protons, and cosmic rays) have a strong impact on the chemistry, hence must be modeled. Aims. We revisit our computation of ionization in the atmosphere of Titan by cosmic rays. The high-energy high-mass ions are taken into account to improve the precision of the calculation of the ion production profile. Methods. The Badhwahr and O Neill model for cosmic ray spectrum was adapted for the Titan model. We used the TransTitan model coupled with the Planetocosmics model to compute the ion production by cosmic rays. We compared the results with the NAIRAS/HZETRN ionization model used for the first time for a body that differs from the Earth. Results. The cosmic ray ionization is computed for five groups of cosmic rays, depending on their charge and mass: protons, alpha, Z = 8 (oxygen), Z = 14 (silicon), and Z = 26 (iron) nucleus. Protons and alpha particles ionize mainly at 65 km altitude, while the higher mass nucleons ionize at higher altitudes. Nevertheless, the ionization at higher altitude is insufficient to obscure the impact of Saturn s magnetosphere protons at a 500 km altitude. The ionization rate at the peak (altitude: 65 km, for all the different conditions) lies between 30 and 40/cu cm/s. Conclusions. These new computations show for the first time the importance of high Z cosmic rays on the ionization of the Titan atmosphere. The updated full ionization profile shape does not differ significantly from that found in our previous calculations (Paper I: Gronoff et al. 2009, 506, 955) but undergoes a strong increase in intensity below an altitude of 400 km, especially between 200 and 400 km altitude where alpha and heavier particles (in the cosmic ray spectrum) are responsible for 40% of the ionization. The comparison of several models of ionization and cosmic ray spectra (in intensity and composition) reassures us about the stability of the altitude of the ionization peak (65 km altitude) with respect to the solar activity.
Bütikofer, R; Flückiger, E O; Desorgher, L; Moser, M R
2008-03-01
In January 2005 toward the end of solar activity cycle 23 the Sun was very active. Between 15 and 20 January 2005, the solar active region NOAA AR 10720 produced five powerful solar flares. In association with this major solar activity several pronounced variations in the ground-level cosmic ray intensity were observed. The fifth of these flares (X7.1) produced energetic solar cosmic rays that caused a giant increase in the count rates of the ground-based cosmic ray detectors (neutron monitors). At southern polar neutron monitor stations the increase of the count rate reached several thousand percent. From the recordings of the worldwide network of neutron monitors, we determined the characteristics of the solar particle flux near Earth. In the initial phase of the event, the solar cosmic ray flux near Earth was extremely anisotropic. The energy spectrum of the solar cosmic rays was fairly soft during the main and the decay phase. We investigated also the flux of different secondary particle species in the atmosphere and the radiation dosage at flight altitude. Our analysis shows a maximum increment of the effective dose rate due to solar cosmic rays in the south polar region around 70 degrees S and 130 degrees E at flight altitude of almost three orders of magnitude.
Dose equivalent on the Moon contributed from cosmic rays and their secondary particles
NASA Astrophysics Data System (ADS)
Hayatsu, K.; Hareyama, Makoto; Hasebe, N.; Kobayashi, S.; Yamashita, N.
Estimation of radiation dose on and under the lunar surface is quite important for human activity on the Moon and in the future lunar bases. Radiation environment on the Moon is much different from that on the Earth. Galactic cosmic rays and solar energetic particles directly penetrate the lunar surface because of no atmosphere and no magnetic field around the Moon. Then, those generate many secondary particles such as gamma rays, neutrons and other charged particles by interaction with soils under the lunar surface. Therefore, the estimation of radiation dose from them on the surface and the underground of the Moon are essential for safety human activities. In this study the ambient dose equivalent in the ICRU sphere at the surface and various depths of the Moon is estimated based on the latest galactic cosmic ray spectrum and its generating secondary particles calculated by the Geant4 code. On the surface the most dominant contribution for the dose are not protons and heliums, but heavy components of galactic cosmic rays such as iron, while in the ground, secondary neutrons are the most dominant. In particular, the dose from neutrons becomes maximal at 50 - 100 g/cm2 of lunar soil depth, because fast neutrons with about 1.0 MeV are mostly produced at this depth and give a large dose. On the surface, the dose originated from GCR is quite sensitive for solar cycle activity, while that from secondary neutrons is not so sensitive. Inversely, under the surface, the dose from neutron is much sensitive for solar activity related to the flux of galactic cosmic rays. This difference should be considered to shield cosmic radiation for human activity on the Moon.
Cosmic ray experimental observations
NASA Technical Reports Server (NTRS)
Balasubrahmanyan, V. K.; Mcdonald, F. B.
1974-01-01
The current experimental situation in cosmic ray studies is discussed, with special emphasis on the development of new detector systems. Topics covered are the techniques for particle identification, energy measurements, gas Cerenkov counters, magnet spectrometers, ionization spectrometers, track detectors, nuclear emulsions, multiparameter analysis using arrays of detectors, the Goddard ionization spectrometer, charge spectra, relative abundances, isotope composition, antinuclei in cosmic rays, electrons, the measurement of cosmic ray arrival directions, and the prehistory of cosmic rays.
Biostack experiment. [Apollo 17 flight
NASA Technical Reports Server (NTRS)
Buecker, H.; Horneck, G.; Reinholz, E.; Ruether, W.; Graul, E. H.; Planel, H.; Soleilhavoup, J. P.; Cueer, P.; Kaiser, R.; Massue, J. P.
1973-01-01
The Apollo 17 biostack experiment to establish the biological efficiency of individual heavy nuclei particles of galactic cosmic radiation are reported. The experiment theory, interaction of heavy nuclei particles with biologic matter, and the total dose of cosmic ionizing radiation are discussed along with the radiation effects of heavy nuclei on Artemia salina eggs, and Bacillus subtilis.
Research in particles and fields. [using spacecraft and balloons
NASA Technical Reports Server (NTRS)
Vogt, R. E.
1974-01-01
Investigations, by particle-detectors flown on spacecraft, of the astrophysical aspects of cosmic radiation and the radiation environment of the earth are reported along with the research of the interplanetary medium, and planetary magnetic fields. The cosmic ray interactions with the interplanetary and interstellar medium, and radio scintillation theory were also studied.
The HZE radiation problem. [highly-charged energetic galactic cosmic rays
NASA Technical Reports Server (NTRS)
Schimmerling, Walter
1990-01-01
Radiation-exposure limits have yet to be established for missions envisioned in the framework of the Space Exploration Initiative. The radiation threat outside the earth's magnetosphere encompasses protons from solar particle events and the highly charged energetic particles constituting galactic cosmic rays; radiation biology entails careful consideration of the extremely nonuniform patterns of such particles' energy deposition. The ability to project such biological consequences of exposure to energetic particles as carcinogenicity currently involves great uncertainties from: (1) different regions of space; (2) the effects of spacecraft structures; and (3) the dose-effect relationships of single traversals of energetic particles.
High-energy particles associated with solar flares
NASA Technical Reports Server (NTRS)
Sakurai, K.; Klimas, A. J.
1974-01-01
High-energy particles, the so-called solar cosmic rays, are often generated in association with solar flares, and then emitted into interplanetary space. These particles, consisting of electrons, protons, and other heavier nuclei, including the iron-group, are accelerated in the vicinity of the flare. By studying the temporal and spatial varation of these particles near the earth's orbit, their storage and release mechanisms in the solar corona and their propagation mechanism can be understood. The details of the nuclear composition and the rigidity spectrum for each nuclear component of the solar cosmic rays are important for investigating the acceleration mechanism in solar flares. The timing and efficiency of the acceleration process can also be investigated by using this information. These problems are described in some detail by using observational results on solar cosmic rays and associated phenomena.
NASA Astrophysics Data System (ADS)
Apel, W. D.; Arteaga-Velázquez, J. C.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Buchholz, P.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Finger, M.; Fuhrmann, D.; Ghia, P. L.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huber, D.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Klages, H. O.; Link, K.; Łuczak, P.; Ludwig, M.; Mathes, H. J.; Mayer, H. J.; Melissas, M.; Milke, J.; Mitrica, B.; Morello, C.; Navarra, G.; Oehlschläger, J.; Ostapchenko, S.; Over, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.
2011-10-01
We report the observation of a steepening in the cosmic ray energy spectrum of heavy primary particles at about 8×1016eV. This structure is also seen in the all-particle energy spectrum, but is less significant. Whereas the “knee” of the cosmic ray spectrum at 3-5×1015eV was assigned to light primary masses by the KASCADE experiment, the new structure found by the KASCADE-Grande experiment is caused by heavy primaries. The result is obtained by independent measurements of the charged particle and muon components of the secondary particles of extensive air showers in the primary energy range of 1016 to 1018eV. The data are analyzed on a single-event basis taking into account also the correlation of the two observables.
NASA Technical Reports Server (NTRS)
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.
NASA Astrophysics Data System (ADS)
Schlickeiser, R.; Oppotsch, J.
2017-12-01
The analytical theory of diffusive acceleration of cosmic rays at parallel stationary shock waves of arbitrary speed with magnetostatic turbulence is developed from first principles. The theory is based on the diffusion approximation to the gyrotropic cosmic-ray particle phase-space distribution functions in the respective rest frames of the up- and downstream medium. We derive the correct cosmic-ray jump conditions for the cosmic-ray current and density, and match the up- and downstream distribution functions at the position of the shock. It is essential to account for the different particle momentum coordinates in the up- and downstream media. Analytical expressions for the momentum spectra of shock-accelerated cosmic rays are calculated. These are valid for arbitrary shock speeds including relativistic shocks. The correctly taken limit for nonrelativistic shock speeds leads to a universal broken power-law momentum spectrum of accelerated particles with velocities well above the injection velocity threshold, where the universal power-law spectral index q≃ 2-{γ }1-4 is independent of the flow compression ratio r. For nonrelativistic shock speeds, we calculate for the first time the injection velocity threshold, settling the long-standing injection problem for nonrelativistic shock acceleration.
Effects of particle drifts on the solar modulation of galactic cosmic rays
NASA Technical Reports Server (NTRS)
Jokipii, J. R.; Levy, E. H.
1977-01-01
Gradient and curvature drifts in an Archimedean-spiral magnetic field are shown to produce a significant effect on the modulation of galactic cosmic rays by the solar wind. The net modulation, heliocentric radial gradient, and average energy change of particles which reach the inner solar system are significantly reduced. The effects of drifts are due to the fact that cosmic rays for which the drift velocity is comparable to the wind velocity or larger, have more rapid access to the inner solar system than in the absence of drifts.
Cosmic censorship of rotating Anti-de Sitter black hole
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gwak, Bogeun; Lee, Bum-Hoon, E-mail: rasenis@sogang.ac.kr, E-mail: bhl@sogang.ac.kr
2016-02-01
We test the validity of cosmic censorship in the rotating anti-de Sitter black hole. For this purpose, we investigate whether the extremal black hole can be overspun by the particle absorption. The particle absorption will change the mass and angular momentum of the black hole, which is analyzed using the Hamilton-Jacobi equations consistent with the laws of thermodynamics. We have found that the mass of the extremal black hole increases more than the angular momentum. Therefore, the outer horizon of the black hole still exists, and cosmic censorship is valid.
Ultrahigh Energy Cosmic Rays: Old Physics or New Physics?
NASA Technical Reports Server (NTRS)
Stecker, F. W.
2004-01-01
We consider the advantages of and the problems associated with hypotheses to explain the origin of ultrahigh energy cosmic rays (UHECR: E greater than 10 EeV) and the "trans-GZK" cosmic rays (TGZK: E greater than 100 EeV) both through "old physics" (acceleration in cosmic sources) and "new physics" (new particles, topological defects, fat neutrino cross sections, Lorentz invariance violation).
Re-evaluation of cosmic ray cutoff terminology
NASA Technical Reports Server (NTRS)
Cooke, D. J.; Humble, J. E.; Shea, M. A.; Smart, D. F.; Lund, N.; Rasmussen, I. L.; Byrnak, B.; Goret, P.; Petrou, N.
1985-01-01
The study of cosmic ray access to locations inside the geomagnetic field has evolved in a manner that has led to some misunderstanding and misapplication of the terminology originally developed to describe particle access. This paper presents what is believed to be a useful set of definitions for cosmic ray cutoff terminology for use in theoretical and experimental cosmic ray studies.
Relative distribution of cosmic rays and magnetic fields
NASA Astrophysics Data System (ADS)
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.
The local time dependence of the anisotropic solar cosmic ray flux.
Smart, D F; Shea, M A
2003-01-01
The distribution of the solar cosmic radiation flux over the earth is not uniform, but the result of complex phenomena involving the interplanetary magnetic field, the geomagnetic field and latitude and longitude of locations on the earth. The latitude effect relates to the geomagnetic shield; the longitude effect relates to local time. For anisotropic solar cosmic ray events the maximum particle flux is always along the interplanetary magnetic field direction, sometimes called the Archimedean spiral path from the sun to the earth. During anisotropic solar cosmic ray event, the locations on the earth viewing "sunward" into the interplanetary magnetic field direction will observe the largest flux (when adjustments are made for the magnetic latitude effect). To relate this phenomena to aircraft routes, for anisotropic solar cosmic ray events that occur during "normal quiescent" conditions, the maximum solar cosmic ray flux (and corresponding solar particle radiation dose) will be observed in the dawn quadrant, ideally at about 06 hours local time. Published by Elsevier Ltd on behalf of COSPAR.
An Inexpensive Cosmic Ray Detector for the Classroom
ERIC Educational Resources Information Center
Goldader, Jeffrey D.; Choi, Seulah
2010-01-01
Finding ways to demonstrate--in a high school classroom--that subatomic particles from space produce other particles capable of reaching the Earth's surface is not a trivial task. In this paper, we describe a Geiger-Muller tube-based cosmic ray coincidence detector we produced at a total cost of less than $200, using two tubes purchased used…
Fermilab Center for Particle Astrophysics | FCPA
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Impacts of Cosmic Dust on Planetary Atmospheres and Surfaces
NASA Astrophysics Data System (ADS)
Plane, John M. C.; Flynn, George J.; Määttänen, Anni; Moores, John E.; Poppe, Andrew R.; Carrillo-Sanchez, Juan Diego; Listowski, Constantino
2018-02-01
Recent advances in interplanetary dust modelling provide much improved estimates of the fluxes of cosmic dust particles into planetary (and lunar) atmospheres throughout the solar system. Combining the dust particle size and velocity distributions with new chemical ablation models enables the injection rates of individual elements to be predicted as a function of location and time. This information is essential for understanding a variety of atmospheric impacts, including: the formation of layers of metal atoms and ions; meteoric smoke particles and ice cloud nucleation; perturbations to atmospheric gas-phase chemistry; and the effects of the surface deposition of micrometeorites and cosmic spherules. There is discussion of impacts on all the planets, as well as on Pluto, Triton and Titan.
Neutral particle background in cosmic ray telescopes composed of silicon solid state detectors
NASA Technical Reports Server (NTRS)
Mewaldt, R. A.; Stone, E. C.; Vogt, R. E.
1977-01-01
The energy loss-spectrum of secondary charged particles produced by the interaction of gamma-rays and energetic neutrons in silicon solid state detectors has been measured with a satellite-borne cosmic ray telescope. In the satellite measurements presented here two distinct neutral background effects are identified: secondary protons and alpha particles with energies of about 2 to 100 MeV produced by neutron interactions, and secondary electrons with energies of about 0.2 to 10 MeV produced by X-ray interactions. The implications of this neutral background for satellite measurements of low energy cosmic rays are discussed, and suggestions are given for applying these results to other detector systems in order to estimate background contamination and optimize detector system design.
Approximate supernova remnant dynamics with cosmic ray production
NASA Technical Reports Server (NTRS)
Voelk, H. J.; Drury, L. O.; Dorfi, E. A.
1985-01-01
Supernova explosions are the most violent and energetic events in the galaxy and have long been considered probably sources of Cosmic Rays. Recent shock acceleration models treating the Cosmic Rays (CR's) as test particles nb a prescribed Supernova Remnant (SNR) evolution, indeed indicate an approximate power law momentum distribution f sub source (p) approximation p(-a) for the particles ultimately injected into the Interstellar Medium (ISM). This spectrum extends almost to the momentum p = 1 million GeV/c, where the break in the observed spectrum occurs. The calculated power law index approximately less than 4.2 agrees with that inferred for the galactic CR sources. The absolute CR intensity can however not be well determined in such a test particle approximation.
Project BIOCORE /M212/, a biological cosmic ray experiment - Procedures, summary, and conclusions
NASA Technical Reports Server (NTRS)
Haymaker, W.; Look, B. C.; Winter, D. L.; Benton, E. V.; Cruty, M. R.
1975-01-01
The primary objective of the experiment was to determine whether a specific portion of the high Z-high energy (HZE) galactic cosmic ray particle spectrum, especially particles with Z no less than 6, can produce microscopically visible injury of brain and eye tissues. Pocket mice (Perognathus longimembris), obtained from the California desert, were selected as the biological target. Five of these mice were flown on Apollo XVII. Not only the brain and eyes but also many other tissues of these animals were studied for evidence of cosmic ray particle damage. The lack of prior experimental evidence as to the character of the potential injury induced by HZE particles required reliance on the physical characteristics of particle radiation in ascertaining the probable nature of the injury. These characteristics and the key aspects of the experiment are summarized in this paper. Subsequent articles in this special supplement give details of the biological, engineering, and dosimetric aspects of BIOCORE together with the results.
NASA Astrophysics Data System (ADS)
Cooper, John F.; Papitashvili, Natalia E.; Johnson, Rita C.; Lal, Nand; McGuire, Robert E.
2015-04-01
NASA now has a large collection of solar, heliospheric, and local interstellar (Voyager 1) cosmic ray particle data sets that can be accessed through the data system services of the NASA Virtual Energetic Particle Observatory (VEPO) in collaboration with the NASA Space Physics Data Facility SPDF), respectively led by the first and last authors. The VEPO services were developed to enhance the long-existing OMNIWeb solar wind and energetic particle services of SPDF for on-line browse, correlative, and statistical analysis of NASA and ESA mission fields, plasma, and energetic particle data. In this presentation we take of tour through VEPO and SPDF of SEP reservoir events, the outer heliosphere earlier surveyed by the Pioneer, Voyager, and Ulysses spacecraft and now being probed by New Horizons, and the heliosheath-heliopause-interstellar regions now being explored by the Voyagers and IBEX. Implications of the latter measurements are also considered for the flux spectra of low to high energy cosmic rays in interstellar space.
NASA Technical Reports Server (NTRS)
Wanjek, Christopher
2003-01-01
Who would have thought cosmic rays could be so hip? Although discovered 90 years ago on death-defying manned balloon flights hip even by twenty-first-century extremesport standards cosmic rays quickly lost popularity as way-cool telescopes were finding way-too-cool phenomena across the electromagnetic spectrum. Yet cosmic rays are back in vogue, boasting their own set of superlatives. Scientists are tracking them down with new resolve from the Arctic to Antarctica and even on the high western plains of Argentina. Theorists, too, now see cosmic rays as harbingers of funky physics. Cosmic rays are atomic and subatomic particles - the fastest moving bits of matter in the universe and the only sample of matter we have from outside the solar system (with the exception of interstellar dust grains). Lower-energy cosmic rays come from the Sun. Mid-energy particles come from stellar explosions - either spewed directly from the star like shrapnel, or perhaps accelerated to nearly the speed of light by shock waves. The highest-energy cosmic rays, whose unequivocal existence remains one of astronomy's greatest mysteries, clock in at a staggering 10(exp 19) to 10(exp 22) electron volts. This is the energy carried in a baseball pitch; seeing as how there are as many atomic particles in a baseball as there are baseballs in the Moon, that s one powerful toss. No simple stellar explosion could produce them. At a recent conference in Albuquerque, scientists presented the first observational evidence of a possible origin for the highest-energy variety. A team led by Elihu Boldt at NASA s Goddard Space Flight Center found that five of these very rare cosmic rays (there are only a few dozen confirmed events) come from the direction of four 'retired' quasar host galaxies just above the arm of the Big Dipper, all visible with backyard telescopes: NGC 3610, NGC 3613, NGC 4589, and NGC 5322. These galaxies are billions of years past their glory days as the brightest beacons in the universe. Yet they still harbor central, supermassive black holes, which could generate energetic particles if they are spinning.
NASA Technical Reports Server (NTRS)
Atwell, William; Koontz, Steve; Normand, Eugene
2012-01-01
Three twentieth century technological developments, 1) high altitude commercial and military aircraft; 2) manned and unmanned spacecraft; and 3) increasingly complex and sensitive solid state micro-electronics systems, have driven an ongoing evolution of basic cosmic ray science into a set of practical engineering tools needed to design, test, and verify the safety and reliability of modern complex technological systems. The effects of primary cosmic ray particles and secondary particle showers produced by nuclear reactions with the atmosphere, can determine the design and verification processes (as well as the total dollar cost) for manned and unmanned spacecraft avionics systems. Similar considerations apply to commercial and military aircraft operating at high latitudes and altitudes near the atmospheric Pfotzer maximum. Even ground based computational and controls systems can be negatively affected by secondary particle showers at the Earth s surface, especially if the net target area of the sensitive electronic system components is large. Finally, accumulation of both primary cosmic ray and secondary cosmic ray induced particle shower radiation dose is an important health and safety consideration for commercial or military air crews operating at high altitude/latitude and is also one of the most important factors presently limiting manned space flight operations beyond low-Earth orbit (LEO). In this paper we review the discovery of cosmic ray effects on the performance and reliability of microelectronic systems as well as human health and the development of the engineering and health science tools used to evaluate and mitigate cosmic ray effects in ground-based atmospheric flight, and space flight environments. Ground test methods applied to microelectronic components and systems are used in combinations with radiation transport and reaction codes to predict the performance of microelectronic systems in their operating environments. Similar radiation transport codes are used to evaluate possible human health effects of cosmic ray exposure, however, the health effects are based on worst-case analysis and extrapolation of a very limited human exposure data base combined with some limited experimental animal data. Finally, the limitations on human space operations beyond low-Earth orbit imposed by long term exposure to galactic cosmic rays are discussed.
On the motion of a quantum particle in the spinning cosmic string space–time
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hassanabadi, H., E-mail: h.hasanabadi@shahroodut.ac.ir; Afshardoost, A.; Zarrinkamar, S.
2015-05-15
We analyze the energy spectrum and the wave function of a particle subjected to magnetic field in the spinning cosmic string space–time and investigate the influence of the spinning reference frame and topological defect on the system. To do this we solve Schrödinger equation in the spinning cosmic string background. In our work, instead of using an approximation in the calculations, we use the quasi-exact ansatz approach which gives the exact solutions for some primary levels. - Highlights: • Solving the Schrödinger equation in the spinning cosmic string space time. • Proposing a quasi-exact analytical solution to the general formmore » of the corresponding equation. • Generalizing the previous works.« less
The Probe of Inflation and Cosmic Origins
NASA Astrophysics Data System (ADS)
Hanany, Shaul; Inflation Probe Mission Study Team
2018-01-01
The Probe of Inflation and Cosmic Origins will map the polarization of the cosmic microwave background over the entire sky with unprecedented sensitivity. It will search for gravity wave signals from the inflationary epoch, thus probing quantum gravity and constraining the energy scale of inflation; it will test the standard model of particle physics by measuring the number of light particles in the Universe and the mass of the neutrino; it will elucidate the nature of dark matter and search for new forms of matter in the early Universe; it will constrain star formation history over cosmic time; and it will determine the mechanisms of structure formation from galaxy cluster to stellar scales. I will review the status of design of this probe-scale mission.
Klein-Gordon oscillator with position-dependent mass in the rotating cosmic string spacetime
NASA Astrophysics Data System (ADS)
Wang, Bing-Qian; Long, Zheng-Wen; Long, Chao-Yun; Wu, Shu-Rui
2018-02-01
A spinless particle coupled covariantly to a uniform magnetic field parallel to the string in the background of the rotating cosmic string is studied. The energy levels of the electrically charged particle subject to the Klein-Gordon oscillator are analyzed. Afterwards, we consider the case of the position-dependent mass and show how these energy levels depend on the parameters in the problem. Remarkably, it shows that for the special case, the Klein-Gordon oscillator coupled covariantly to a homogeneous magnetic field with the position-dependent mass in the rotating cosmic string background has the similar behaviors to the Klein-Gordon equation with a Coulomb-type configuration in a rotating cosmic string background in the presence of an external magnetic field.
Detection of Ultrahigh-Energy Cosmic Rays with the Auger Engineering Radio Array
NASA Astrophysics Data System (ADS)
Krause, Raphael; Pierre Auger Collaboration
2017-02-01
Ultrahigh-energy cosmic rays interact with the Earth's atmosphere and produce great numbers of secondary particles forming an extensive air shower. These air showers emit radiation in the radio frequency range which delivers important information about the processes of radio emission in extensive air showers and properties of the primary cosmic rays, e.g. arrival direction, energy and mass with a duty cycle close to 100%. The radio extension of the world's largest cosmic-ray experiment, the Pierre Auger Observatory, is called the Auger Engineering Radio Array (AERA). In addition to the particle and fluorescence detectors of the Pierre Auger Observatory, AERA investigates the electromagnetic component of extensive air showers using 153 autonomous radio stations on an area of 17km2 .
Studies of High Energy Particle Astrophysics
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nitz, David F; Fick, Brian E
This report covers the progress of the Michigan Technological University particle astrophysics group during the period April 15th, 2011 through April 30th, 2014. The principal investigator is Professor David Nitz. Professor Brian Fick is the Co-PI. The focus of the group is the study of the highest energy cosmic rays using the Pierre Auger Observatory. The major goals of the Pierre Auger Observatory are to discover and understand the source or sources of cosmic rays with energies exceeding 10**19 eV, to identify the particle type(s), and to investigate the interactions of those cosmic particles both in space and in themore » Earth's atmosphere. The Pierre Auger Observatory in Argentina was completed in June 2008 with 1660 surface detector stations and 24 fluorescence telescopes arranged in 4 stations. It has a collecting area of 3,000 square km, yielding an aperture of 7,000 km**2 sr.« less
NASA Technical Reports Server (NTRS)
Blanford, G. E., Jr.; Friedlander, M. W.; Klarmann, J.; Walker, R. M.; Wefel, J. P.
1973-01-01
Large areas of plastic detectors and nuclear emulsions were exposed to the primary cosmic radiation on two high-altitude balloon flights in May 1968 and September 1969. From measurements on the tracks found in the scanning of the plastic detectors, events with charges Z greater than 50 were selected, and these data were consolidated with those from our earlier flights. Several conclusions can be drawn from the observed charge spectrum. The detection of trans-bismuth nuclei confirms earlier observations of these particles in the cosmic rays. However, no trans-uranium particles were observed. Detailed features of the charge spectrum cannot be explained by nuclei from r-process nucleosynthesis alone. Although the addition of particles following s-process abundances yields improved agreement, the spectrum appears more complicated than would result from a simple combination of r- and s-process abundances with identical propagation histories.
All-particle cosmic ray energy spectrum measured by the HAWC experiment from 10 to 500 TeV
NASA Astrophysics Data System (ADS)
Alfaro, R.; Alvarez, C.; Álvarez, J. D.; Arceo, R.; Arteaga-Velázquez, J. C.; Avila Rojas, D.; Ayala Solares, H. A.; Barber, A. S.; Becerril, A.; Belmont-Moreno, E.; BenZvi, S. Y.; Brisbois, C.; Caballero-Mora, K. S.; Capistrán, T.; Carramiñana, A.; Casanova, S.; Castillo, M.; Cotti, U.; Cotzomi, J.; Coutiño de León, S.; De León, C.; De la Fuente, E.; Diaz Hernandez, R.; Dichiara, S.; Dingus, B. L.; DuVernois, M. A.; Díaz-Vélez, J. C.; Ellsworth, R. W.; Enriquez-Rivera, O.; Fiorino, D. W.; Fleischhack, H.; Fraija, N.; García-González, J. A.; González Muñoz, A.; González, M. M.; Goodman, J. A.; Hampel-Arias, Z.; Harding, J. P.; Hernandez-Almada, A.; Hinton, J.; Hueyotl-Zahuantitla, F.; Hui, C. M.; Hüntemeyer, P.; Iriarte, A.; Jardin-Blicq, A.; Joshi, V.; Kaufmann, S.; Lara, A.; Lauer, R. J.; Lennarz, D.; León Vargas, H.; Linnemann, J. T.; Longinotti, A. L.; Luis Raya, G.; Luna-García, R.; López-Cámara, D.; López-Coto, R.; Malone, K.; Marinelli, S. S.; Martinez, O.; Martinez-Castellanos, I.; Martínez-Castro, J.; Martínez-Huerta, H.; Matthews, J. A.; Miranda-Romagnoli, P.; Moreno, E.; Mostafá, M.; Nellen, L.; Newbold, M.; Nisa, M. U.; Noriega-Papaqui, R.; Pelayo, R.; Pretz, J.; Pérez-Pérez, E. G.; Ren, Z.; Rho, C. D.; Rivière, C.; Rosa-González, D.; Rosenberg, M.; Ruiz-Velasco, E.; Salesa Greus, F.; Sandoval, A.; Schneider, M.; Schoorlemmer, H.; Sinnis, G.; Smith, A. J.; Springer, R. W.; Surajbali, P.; Taboada, I.; Tibolla, O.; Tollefson, K.; Torres, I.; Ukwatta, T. N.; Villaseñor, L.; Weisgarber, T.; Westerhoff, S.; Wood, J.; Yapici, T.; Zepeda, A.; Zhou, H.; HAWC Collaboration
2017-12-01
We report on the measurement of the all-particle cosmic ray energy spectrum with the High Altitude Water Cherenkov (HAWC) Observatory in the energy range 10 to 500 TeV. HAWC is a ground-based air-shower array deployed on the slopes of Volcan Sierra Negra in the state of Puebla, Mexico, and is sensitive to gamma rays and cosmic rays at TeV energies. The data used in this work were taken over 234 days between June 2016 and February 2017. The primary cosmic-ray energy is determined with a maximum likelihood approach using the particle density as a function of distance to the shower core. Introducing quality cuts to isolate events with shower cores landing on the array, the reconstructed energy distribution is unfolded iteratively. The measured all-particle spectrum is consistent with a broken power law with an index of -2.49 ±0.01 prior to a break at (45.7 ±0.1 ) TeV , followed by an index of -2.71 ±0.01 . The spectrum also represents a single measurement that spans the energy range between direct detection and ground-based experiments. As a verification of the detector response, the energy scale and angular resolution are validated by observation of the cosmic ray Moon shadow's dependence on energy.
Adriani, O; Barbarino, G C; Bazilevskaya, G A; Bellotti, R; Boezio, M; Bogomolov, E A; Bongi, M; Bonvicini, V; Bottai, S; Bruno, A; Cafagna, F; Campana, D; Carlson, P; Casolino, M; Castellini, G; De Santis, C; Di Felice, V; Galper, A M; Karelin, A V; Koldashov, S V; Koldobskiy, S A; Krutkov, S Y; Kvashnin, A N; Leonov, A; Malakhov, V; Marcelli, L; Martucci, M; Mayorov, A G; Menn, W; Mergé, M; Mikhailov, V V; Mocchiutti, E; Monaco, A; Mori, N; Munini, R; Osteria, G; Panico, B; Papini, P; Pearce, M; Picozza, P; Ricci, M; Ricciarini, S B; Simon, M; Sparvoli, R; Spillantini, P; Stozhkov, Y I; Vacchi, A; Vannuccini, E; Vasilyev, G I; Voronov, S A; Yurkin, Y T; Zampa, G; Zampa, N; Potgieter, M S; Vos, E E
2016-06-17
Cosmic-ray electrons and positrons are a unique probe of the propagation of cosmic rays as well as of the nature and distribution of particle sources in our Galaxy. Recent measurements of these particles are challenging our basic understanding of the mechanisms of production, acceleration, and propagation of cosmic rays. Particularly striking are the differences between the low energy results collected by the space-borne PAMELA and AMS-02 experiments and older measurements pointing to sign-charge dependence of the solar modulation of cosmic-ray spectra. The PAMELA experiment has been measuring the time variation of the positron and electron intensity at Earth from July 2006 to December 2015 covering the period for the minimum of solar cycle 23 (2006-2009) until the middle of the maximum of solar cycle 24, through the polarity reversal of the heliospheric magnetic field which took place between 2013 and 2014. The positron to electron ratio measured in this time period clearly shows a sign-charge dependence of the solar modulation introduced by particle drifts. These results provide the first clear and continuous observation of how drift effects on solar modulation have unfolded with time from solar minimum to solar maximum and their dependence on the particle rigidity and the cyclic polarity of the solar magnetic field.
Investigation of the properties of galactic cosmic rays with the KASCADE-Grande experiment
NASA Astrophysics Data System (ADS)
Hörandel, J. R.; Apel, W. D.; Arteaga, J. C.; Badea, F.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Brüggemann, M.; Buchholz, P.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Finger, M.; Fuhrmann, D.; Ghia, P. L.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Kickelbick, D.; Klages, H. O.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Mitrica, B.; Morello, C.; Navarra, G.; Nehls, S.; Oehlschläger, J.; Ostapchenko, S.; Over, S.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schröder, F.; Sima, O.; Stümpert, M.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.
2011-02-01
The properties of galactic cosmic rays are investigated with the KASCADE-Grande experiment in the energy range between 1014 and 1018 eV. Recent results are discussed. They concern mainly the all-particle energy spectrum and the elemental composition of cosmic rays.
Probing the cosmic causes of errors in supercomputers
DOE Office of Scientific and Technical Information (OSTI.GOV)
None
Cosmic rays from outer space are causing errors in supercomputers. The neutrons that pass through the CPU may be causing binary data to flip leading to incorrect calculations. Los Alamos National Laboratory has developed detectors to determine how much data is being corrupted by these cosmic particles.
Blasi, Pasquale
2017-12-22
Cosmic Rays reach the Earth from space with energies of up to more than 1020 eV, carrying information on the most powerful particle accelerators that Nature has been able to assemble. Understanding where and how cosmic rays originate has required almost one century of investigations, and, although the last word is not written yet, recent observations and theory seem now to fit together to provide us with a global picture of the origin of cosmic rays of unprecedented clarity. Here we will describe what we learned from recent observations of astrophysical sources (such as supernova remnants and active galaxies) and we will illustrate what these observations tell us about the physics of particle acceleration and transport. We will also discuss the âendâ of the Galactic cosmic ray spectrum, which bridges out attention towards the so called ultra high energy cosmic rays (UHECRs). At ~1020 eV the gyration scale of cosmic rays in cosmic magnetic fields becomes large enough to allow us to point back to their sources, thereby allowing us to perform âcosmic ray astronomyâ, as confirmed by the recent results obtained with the Pierre Auger Observatory. We will discuss the implications of these observations for the understanding of UHECRs, as well as some questions which will likely remain unanswered and will be the target of the next generation of cosmic ray experiments.
Measuring momentum for charged particle tomography
Morris, Christopher; Fraser, Andrew Mcleod; Schultz, Larry Joe; Borozdin, Konstantin N.; Klimenko, Alexei Vasilievich; Sossong, Michael James; Blanpied, Gary
2010-11-23
Methods, apparatus and systems for detecting charged particles and obtaining tomography of a volume by measuring charged particles including measuring the momentum of a charged particle passing through a charged particle detector. Sets of position sensitive detectors measure scattering of the charged particle. The position sensitive detectors having sufficient mass to cause the charged particle passing through the position sensitive detectors to scatter in the position sensitive detectors. A controller can be adapted and arranged to receive scattering measurements of the charged particle from the charged particle detector, determine at least one trajectory of the charged particle from the measured scattering; and determine at least one momentum measurement of the charged particle from the at least one trajectory. The charged particle can be a cosmic ray-produced charged particle, such as a cosmic ray-produced muon. The position sensitive detectors can be drift cells, such as gas-filled drift tubes.
Cosmic Ray Transport in the Distant Heliosheath
NASA Technical Reports Server (NTRS)
Florinski, V.; Adams, James H.; Washimi, H.
2011-01-01
The character of energetic particle transport in the distant heliosheath and especially in the vicinity of the heliopause could be quite distinct from the other regions of the heliosphere. The magnetic field structure is dominated by a tightly wrapped oscillating heliospheric current sheet which is transported to higher latitudes by the nonradial heliosheath flows. Both Voyagers have, or are expected to enter a region dominated by the sectored field formed during the preceding solar maximum. As the plasma flow slows down on approach to the heliopause, the distance between the folds of the current sheet decreases to the point where it becomes comparable to the cyclotron radius of an energetic ion, such as a galactic cosmic ray. Then, a charged particle can effectively drift across a stack of magnetic sectors with a speed comparable with the particle s velocity. Cosmic rays should also be able to efficiently diffuse across the mean magnetic field if the distance between sector boundaries varies. The region of the heliopause could thus be much more permeable to cosmic rays than was previously thought. This new transport proposed mechanism could explain the very high intensities (approaching the model interstellar values) of galactic cosmic rays measured by Voyager 1 during 2010-2011.
Measurements of Amplified Magnetic Field and Cosmic-Ray Content in Supernova Remnants
NASA Astrophysics Data System (ADS)
Uchiyama, Yasunobu
Supernova explosions drive collisionless shocks in the interstellar (or circumstellar) medium. Such shocks are mediated by plasma waves, resulting in the shock transition on a scale much smaller than the collisional mean free path. Galactic cosmic rays are widely considered to be accelerated at collisionless shocks in supernova remnants via diffusive shock acceleration. New high-energy data coming from the X-ray and gamma-ray satellites and from imaging air Cerenkov telescopes are making possible to study physics of particle acceleration at supernova shocks, such as magnetic field amplification which is considered to be realized as part of shock acceleration process and the energy content of cosmic-ray particles in the supernova shell. In particular, GeV observations with the Fermi Gamma-ray Space Telescope offer the prime means to establish the origin of the gamma-rays, and to measure the cosmic-ray content. Moreover they provide a new opportunity to learn about how particle acceleration responds to environ-mental effects. I will present recent observational results from the Chandra and Suzaku X-ray satellites and new results from the LAT onboard Fermi, and discuss their implications to the origin of galactic cosmic rays.
Geomagnetic Cutoff Rigidity Computer Program: Theory, Software Description and Example
NASA Technical Reports Server (NTRS)
Smart, D. F.; Shea, M. A.
2001-01-01
The access of charged particles to the earth from space through the geomagnetic field has been of interest since the discovery of the cosmic radiation. The early cosmic ray measurements found that cosmic ray intensity was ordered by the magnetic latitude and the concept of cutoff rigidity was developed. The pioneering work of Stoermer resulted in the theory of particle motion in the geomagnetic field, but the fundamental mathematical equations developed have 'no solution in closed form'. This difficulty has forced researchers to use the 'brute force' technique of numerical integration of individual trajectories to ascertain the behavior of trajectory families or groups. This requires that many of the trajectories must be traced in order to determine what energy (or rigidity) a charged particle must have to penetrate the magnetic field and arrive at a specified position. It turned out the cutoff rigidity was not a simple quantity but had many unanticipated complexities that required many hundreds if not thousands of individual trajectory calculations to solve. The accurate calculation of particle trajectories in the earth's magnetic field is a fundamental problem that limited the efficient utilization of cosmic ray measurements during the early years of cosmic ray research. As the power of computers has improved over the decades, the numerical integration procedure has grown more tractable, and magnetic field models of increasing accuracy and complexity have been utilized. This report is documentation of a general FORTRAN computer program to trace the trajectory of a charged particle of a specified rigidity from a specified position and direction through a model of the geomagnetic field.
Observations of ultraheavy cosmic ray particles at 10 GV cutoff rigidity
NASA Technical Reports Server (NTRS)
Yanagimachi, T.; Hisano, K.; Ito, K.; Kobayashi, S.; Doke, T.; Hamasaki, R.; Hayashi, T.; Yakenaka, T.; Nagata, K.
1985-01-01
Ultraheavy cosmic ray particles with Z 45 and Fe were observed in two balloon flights at a mean geomagnetic cutoff rigidity of 10 GV. Fluxes of these particles at the top of the atmosphere are presented. A ratio of (Z 45)/(Fe) is compared with other experimental results. The ratio decreases with increasing energy in the energy range from 1 to 10 GeV/amu. A possibility is presented to explain the variation of the ratio with energy.
Nuclear Physics in Space: What We Can Learn From Cosmic Rays
NASA Technical Reports Server (NTRS)
Moskalenko, Igor V.
2004-01-01
Studies and discoveries in cosmic-ray physics and generally in Astrophysics provide a fertile ground for research in many areas of Particle Physics and Cosmology, such as the search for dark matter, antimatter, new particles, and exotic physics, studies of the nucleosynthesis, origin of Galactic and extragalactic gamma-ray diffuse emission, formation of the large scale structure of the universe etc. In several years new missions are planned for cosmic-ray experiments, which will tremendously increase the quality and accuracy of cosmic-ray data. On the other hand, direct measurements of cosmic rays are possible in only one location on the outskirts of the Milky Way galaxy and present only a snapshot of very dynamic processes. It has been recently realized that direct information about the fluxes and spectra of cosmic rays in distant locations is provided by the Galactic diffuse gamma-rays, therefore, complementing the local cosmic-ray studies. A wealth of information is also contained in the isotopic abundances of cosmic rays, therefore, accurate evaluation of the isotopic production cross sections is of primary importance for Astrophysics of cosmic rays, studies of the galactic chemical evolution, and Cosmology. In this talk, I will show new results obtained with GALPROP, the most advanced numerical model for cosmic-ray propagation, which includes in a self-consistent way all cosmic-ray species (stable and long-lived radioactive isotopes from H to Ni, antiprotons, positrons and electrons, gamma rays and synchrotron radiation), and all relevant processes and reactions.
New upper limit on strange quark matter abundance in cosmic rays with the PAMELA space experiment.
Adriani, O; Barbarino, G C; Bazilevskaya, G A; Bellotti, R; Boezio, M; Bogomolov, E A; Bongi, M; Bonvicini, V; Bottai, S; Bruno, A; Cafagna, F; Campana, D; Carlson, P; Casolino, M; Castellini, G; De Donato, C; De Santis, C; De Simone, N; Di Felice, V; Formato, V; Galper, A M; Karelin, A V; Koldashov, S V; Koldobskiy, S; Krutkov, S Y; Kvashnin, A N; Leonov, A; Malakhov, V; Marcelli, L; Martucci, M; Mayorov, A G; Menn, W; Mergè, M; Mikhailov, V V; Mocchiutti, E; Monaco, A; Mori, N; Munini, R; Osteria, G; Palma, F; Panico, B; Papini, P; Pearce, M; Picozza, P; Ricci, M; Ricciarini, S B; Sarkar, R; Scotti, V; Simon, M; Sparvoli, R; Spillantini, P; Stozhkov, Y I; Vacchi, A; Vannuccini, E; Vasilyev, G; Voronov, S A; Yurkin, Y T; Zampa, G; Zampa, N
2015-09-11
In this work we present results of a direct search for strange quark matter (SQM) in cosmic rays with the PAMELA space spectrometer. If this state of matter exists it may be present in cosmic rays as particles, called strangelets, having a high density and an anomalously high mass-to-charge (A/Z) ratio. A direct search in space is complementary to those from ground-based spectrometers. Furthermore, it has the advantage of being potentially capable of directly identifying these particles, without any assumption on their interaction model with Earth's atmosphere and the long-term stability in terrestrial and lunar rocks. In the rigidity range from 1.0 to ∼1.0×10^{3} GV, no such particles were found in the data collected by PAMELA between 2006 and 2009. An upper limit on the strangelet flux in cosmic rays was therefore set for particles with charge 1≤Z≤8 and mass 4≤A≤1.2×10^{5}. This limit as a function of mass and as a function of magnetic rigidity allows us to constrain models of SQM production and propagation in the Galaxy.
A new population of very high energy gamma-ray sources in the Milky Way.
Aharonian, F; Akhperjanian, A G; Aye, K-M; Bazer-Bachi, A R; Beilicke, M; Benbow, W; Berge, D; Berghaus, P; Bernlöhr, K; Boisson, C; Bolz, O; Borgmeier, C; Braun, I; Breitling, F; Brown, A M; Gordo, J Bussons; Chadwick, P M; Chounet, L-M; Cornils, R; Costamante, L; Degrange, B; Djannati-Ataï, A; Drury, L O'C; Dubus, G; Ergin, T; Espigat, P; Feinstein, F; Fleury, P; Fontaine, G; Funk, S; Gallant, Y A; Giebels, B; Gillessen, S; Goret, P; Hadjichristidis, C; Hauser, M; Heinzelmann, G; Henri, G; Hermann, G; Hinton, J A; Hofmann, W; Holleran, M; Horns, D; de Jager, O C; Jung, I; Khélifi, B; Komin, Nu; Konopelko, A; Latham, I J; Le Gallou, R; Lemière, A; Lemoine, M; Leroy, N; Lohse, T; Marcowith, A; Masterson, C; McComb, T J L; de Naurois, M; Nolan, S J; Noutsos, A; Orford, K J; Osborne, J L; Ouchrif, M; Panter, M; Pelletier, G; Pita, S; Pühlhofer, G; Punch, M; Raubenheimer, B C; Raue, M; Raux, J; Rayner, S M; Redondo, I; Reimer, A; Reimer, O; Ripken, J; Rob, L; Rolland, L; Rowell, G; Sahakian, V; Saugé, L; Schlenker, S; Schlickeiser, R; Schuster, C; Schwanke, U; Siewert, M; Sol, H; Steenkamp, R; Stegmann, C; Tavernet, J-P; Terrier, R; Théoret, C G; Tluczykont, M; van der Walt, D J; Vasileiadis, G; Venter, C; Vincent, P; Visser, B; Völk, H J; Wagner, S J
2005-03-25
Very high energy gamma-rays probe the long-standing mystery of the origin of cosmic rays. Produced in the interactions of accelerated particles in astrophysical objects, they can be used to image cosmic particle accelerators. A first sensitive survey of the inner part of the Milky Way with the High Energy Stereoscopic System (HESS) reveals a population of eight previously unknown firmly detected sources of very high energy gamma-rays. At least two have no known radio or x-ray counterpart and may be representative of a new class of "dark" nucleonic cosmic ray sources.
Biomedical experiments. Part A: Biostack experiment
NASA Technical Reports Server (NTRS)
Buecker, H.; Horneck, G.; Reinholz, E.; Scheuermann, W.; Ruether, W.; Graul, E. H.; Planel, H.; Soleilhavoup, J. P.; Cuer, P.; Kaiser, R.
1972-01-01
The biostack experiment is described which was designed to study the biologic effects of individual heavy nuclei of galactic cosmic radiation during space flight outside the magnetosphere of the earth. Specifically, the biostack experiment was designed to promote research on the effects of high energy/high Z particles of galactic cosmic radiation on a broad spectrum of biologic systems, from the molecular to the highly organized and developed forms of life. The experiment was considered unique and scientifically meritorious because of its potential yield of information - currently unavailable on earth - on the interaction of biologic systems with the heavy particles of galactic cosmic radiation.
NASA Technical Reports Server (NTRS)
Goldstein, M. L.
1977-01-01
In a study of cosmic ray propagation in interstellar and interplanetary space, a perturbed orbit resonant scattering theory for pitch angle diffusion in a slab model of magnetostatic turbulence is slightly generalized and used to compute the diffusion coefficient for spatial propagation parallel to the mean magnetic field. This diffusion coefficient has been useful for describing the solar modulation of the galactic cosmic rays, and for explaining the diffusive phase in solar flares in which the initial anisotropy of the particle distribution decays to isotropy.
Reanalysis of porous chondritic cosmic dust particles
NASA Astrophysics Data System (ADS)
Kapisinsky, I.; Figusch, V.; Ivan, J.; Izdinsky, K.; Zemankova, M.
2001-10-01
The particles reanalysed in this study were obtained from the NASA Johnson Space Center (JSC) Cosmic Dust Collection. The reanalysis of the particle L2008 P9 indicates typical assemblage of olivine - pyroxene. This sample can be classified as a chondritic porous IDP with the metallic phase grain containing essential amount of nickel and copper (the latter element is most probably due to instrumental artefact). The chemical composition of the particle L2011 S5 corresponds mostly to an assemblage of pyroxene phase - (Mg,Fe,Ni)SiO_3 roughly 75 wt.% and a sulphide phase - probably pyrrhotite (Fe,Ni)S about 25 wt.%.
Cosmogenic-nuclide production by primary cosmic-ray protons
NASA Technical Reports Server (NTRS)
Reedy, R. C.
1985-01-01
The production rates of cosmogenic nuclides were calculated for the primary protons in the galactic and solar cosmic rays. At 1 AU, the long-term average fluxes of solar protons usually produce many more atoms of cosmogenic nuclide than the primary protons in the galactic cosmic rays (GCR). Because the particle fluxes inside meteorites and other large objects in space include many secondary neutrons, the production rates and ratios inside large objects are often very different from those by just the primary GCR protons. It is possible to determine if a small object, was small in space or broken from a meteorite. Because heliospherical modulation and other interactions change the GCR particle spectrum, the production of cosmogenic nuclides by the GCR particles outside the heliosphere will be different from that by modulated GCR primaries.
REVIEWS OF TOPICAL PROBLEMS: Acceleration of cosmic rays by shock waves
NASA Astrophysics Data System (ADS)
Berezhko, E. G.; Krymskiĭ, G. F.
1988-01-01
Theoretical work on various processes by which shock waves accelerate cosmic rays is reviewed. The most efficient of these processes, Fermi acceleration, is singled out for special attention. A linear theory for this process is presented. The results found on the basis of nonlinear models of Fermi acceleration, which incorporate the modification of the structure caused by the accelerated particles, are reported. There is a discussion of various possibilities for explaining the generation of high-energy particles observed in interplanetary and interstellar space on the basis of a Fermi acceleration mechanism. The acceleration by shock waves from supernova explosions is discussed as a possible source of galactic cosmic rays. The most important unresolved questions in the theory of acceleration of charged particles by shock waves are pointed out.
NASA Technical Reports Server (NTRS)
1974-01-01
An X-ray observation of the Norma-Lupus region, charge and isotope measurements of heavy cosmic ray nuclei and their role in the determination of cosmic ray age, and the possibility of a contribution to primary cosmic ray spectra from pulsars are among the topics covered in papers concerned with some of the results of recent cosmic ray research. Other topics covered include multiple scattering of charged particles in magnetic fields, absorption of primary cosmic rays in the atmosphere, and phase lag effects on cosmic ray modulation during a recent solar cycle. Individual items are announced in this issue.
Underground measurements on secondary cosmic rays
NASA Technical Reports Server (NTRS)
Wilson, C. W.; Fenton, A. G.; Fenton, K. B.
1985-01-01
Measurements made at the Poatina cosmic ray station (41.8 S 149.9 E, 347 m.w.e.) from August 1983 to July 1984 are summarized. The cosmic ray primary particles responsible for events detected at the station have a median primary energy of 1.2 TeV. The motivation for part of this work came from the reported detection of narrow angle anisotropies in the arrival direction of cosmic rays.
Landau quantization in the spinning cosmic string spacetime
DOE Office of Scientific and Technical Information (OSTI.GOV)
Muniz, C.R., E-mail: celiomuniz@yahoo.com; Bezerra, V.B.; Cunha, M.S.
2014-11-15
We analyze the quantum phenomenon arising from the interaction of a spinless charged particle with a rotating cosmic string, under the action of a static and uniform magnetic field parallel to the string. We calculate the energy levels of the particle in the non-relativistic approach, showing how these energies depend on the parameters involved in the problem. In order to do this, we solve the time independent Schrödinger equation in the geometry of the spinning cosmic string, taking into account that the coupling between the rotation of the spacetime and the angular momentum of the particle is very weak, suchmore » that makes sense to apply the Schrödinger equation in a curved background whose metric has an off diagonal term which involves time and space. It is also assumed that the particle orbits sufficiently far from the boundary of the region of closed timelike curves which exist around this topological defect. Finally, we find the Landau levels of the particle in the presence of a spinning cosmic string endowed with internal structure, i.e., having a finite width and uniformly filled with both material and vacuum energies. - Highlights: • Solution of the wave equation characterizing the problem. • Energy levels of the particle in spacetime of the structureless string. • Expression for an analogous of the quadratic Zeeman effect. • Energy levels of the particle in spacetime of the string with internal structure. • Evidence of the string structure by the internal existence of the vacuum energy.« less
NASA Astrophysics Data System (ADS)
Pietroni, M.
2009-02-01
All the non-trivial features of the Universe we see around us, such as particles, stars, galaxies, and clusters of galaxies, are the result of non-equilibrium processes in the cosmic evolution. These lectures aim to provide some general background in cosmology and to examine specific, and notable, examples of departures from thermal equilibrium. They are organized as follows: 1) Overview of the thermal history of the Universe after the Big Bang: the relevant time-scales and the mechanism of particle decoupling from the themal bath; 2) Explicit examples of cosmic relics: nucleosynthesis, photons and the cosmic microwave background, neutrinos, and cold dark matter; 3) Baryogenesis: the generation of the baryon asymmetry of the Universe; 4) The formation of cosmic structures (galaxies, clusters of galaxies): from the Vlasov equation to the renormalization group.
Measurement of the degree of anisotropy of the cosmic radiation using the IMP space vehicle
NASA Technical Reports Server (NTRS)
Palmeira, R. A. R.; Allum, F. R.
1972-01-01
The detector and data reduction techniques used in connection with the cosmic ray experiments designed for and flown on Explorer 34 and 41 satellites are described. A history of the program development and the present status of data processing are briefly summarized. The instrument to measure the anisotropy and energy spectra of cosmic ray electrons and protons, and X-rays of solar and galactic origin is discussed. The main characteristics of the detectors and the stability during 23 months of operation are described. The method of analysis of the angular distribution of solar cosmic ray particles in the ecliptic plane is given. It is shown that the anisotropy of low energy particles of solar origin decreases sharply to a very small value when the satellite penetrates the magnetosphere.
NASA Astrophysics Data System (ADS)
Mocchiutti, E.; Ambriola, M.; Bartalucci, S.; Bellotti, R.; Bergström, D.; Boezio, M.; Bonvicini, V.; Bravar, U.; Cafagna, F.; Carlson, P.; Casolino, M.; Ciacio, F.; Circella, M.; De Marzo, C. N.; De Pascale, M. P.; Francke, T.; Hansen, P.; Hof, M.; Kremer, J.; Menn, W.; Mitchell, J. W.; Morselli, A.; Ormes, J. F.; Papini, P.; Stephens, S. A.; Stochaj, S. J.; Streitmatter, R. E.; Suffert, M.; Vacchi, A.; Vannuccini, E.; Zampa, N.
2003-07-01
We report a measurement of the composition and spectra of both the primary and secondary cosmic ray particles at different depths in the atmosphere. The data were collected by the balloon-b orne experiment CAPRICE98 during the ascent of the payload on 28 May 1998 from Fort Sumner, New Mexico. The identification of various kinds of particles, such as, protons, deuterons, helium nuclei, electrons and positrons was possible in various energy ranges depending on the kind of particle and the particle background at different residual atmosphere. These measurements, together with the atmospheric muon spectra, will allow fine-tuning of models used in air shower simulations.
Direct observations of galactic cosmic rays
NASA Astrophysics Data System (ADS)
Müller, Dietrich
2012-08-01
The mysterious " radiation ... entering our atmosphere from above" discovered by Hess in 1912 is now known to be dominated by relativistic charged particles, mostly with energies in the GeV-range, but extending to energies higher by many orders of magnitude. As none of these particles can penetrate the earth's atmosphere without interaction, detailed studies of their composition and energy spectra require observations with high-altitude balloons or spacecraft. This became possible only towards the middle of the 20th century. The direct measurements have now revealed much detail about the Galactic cosmic rays below 1015eV, but do not yet provide much overlap with the air-shower region of energies. A historic overview of the measurements is given, beginning with the realization that the majority of the cosmic rays are protons. The discovery and astrophysical significance of the heavier nuclei, and of the ultra-heavy nuclei beyond iron and up to the actinides, are then described, and measurements of the isotopic composition are discussed. Observations of the individual energy spectra are reviewed, and finally, the detection of electrons, positrons, and anti-protons in the cosmic rays, and the searches for exotic or unusual phenomena are summarized. Emphasis is given to the fact that all of these discoveries have become possible through the evolution of increasingly sophisticated detection techniques, a process that is continuing through the present time. The precise knowledge of the abundance distributions of the elements in the cosmic rays and of their isotopic composition permits a comparison with the "universal abundance scale" and provides strong constraints on the origin of the cosmic-ray material in the interstellar medium. "Clock-isotopes" reveal the time history of the particles. The shapes of the energy spectra of the individual cosmic-ray components are related to evolving ideas about particle acceleration and propagation in the Galaxy. In conclusion, prospects for future work are briefly discussed.
Enhancements of energetic particles near the heliospheric termination shock.
McDonald, Frank B; Stone, Edward C; Cummings, Alan C; Heikkila, Bryant; Lal, Nand; Webber, William R
2003-11-06
The spacecraft Voyager 1 is at a distance greater than 85 au from the Sun, in the vicinity of the termination shock that marks the abrupt slowing of the supersonic solar wind and the beginning of the extended and unexplored distant heliosphere. This shock is expected to accelerate 'anomalous cosmic rays', as well as to re-accelerate Galactic cosmic rays and low-energy particles from the inner Solar System. Here we report a significant increase in the numbers of energetic ions and electrons that persisted for seven months beginning in mid-2002. This increase differs from any previously observed in that there was a simultaneous increase in Galactic cosmic ray ions and electrons, anomalous cosmic rays and low-energy ions. The low-intensity level and spectral energy distribution of the anomalous cosmic rays, however, indicates that Voyager 1 still has not reached the termination shock. Rather, the observed increase is an expected precursor event. We argue that the radial anisotropy of the cosmic rays is expected to be small in the foreshock region, as is observed.
NASA Astrophysics Data System (ADS)
Camera, Stefano; Fornasa, Mattia; Fornengo, Nicolao; Regis, Marco
2013-07-01
Both cosmic shear and cosmological gamma-ray emission stem from the presence of dark matter (DM) in the universe: DM structures are responsible for the bending of light in the weak-lensing regime and those same objects can emit gamma rays, either because they host astrophysical sources (active galactic nuclei or star-forming galaxies) or directly by DM annihilations (or decays, depending on the properties of the DM particle). Such gamma rays should therefore exhibit strong correlation with the cosmic shear signal. In this Letter, we compute the cross-correlation angular power spectrum of cosmic shear and gamma rays produced by the annihilation/decay of weakly interacting massive particle DM, as well as by astrophysical sources. We show that this observable provides novel information on the composition of the extragalactic gamma-ray background (EGB), since the amplitude and shape of the cross-correlation signal strongly depend on which class of sources is responsible for the gamma-ray emission. If the DM contribution to the EGB is significant (at least in a definite energy range), although compatible with current observational bounds, its strong correlation with the cosmic shear makes such signal potentially detectable by combining Fermi Large Area Telescope data with forthcoming galaxy surveys, like the Dark Energy Survey and Euclid. At the same time, the same signal would demonstrate that the weak-lensing observables are indeed due to particle DM matter and not to possible modifications of general relativity.
How large is the cosmic dust flux into the Earth's atmosphere?
NASA Astrophysics Data System (ADS)
Plane, John; Janches, Diego; Gomez-Martin, Juan Carlos; Bones, David; Diego Carrillo-Sanchez, Juan; James, Sandy; Nesvorny, David; Pokorny, Petr
2016-07-01
Cosmic dust particles are produced in the solar system from the sublimation of comets as they orbit close to the sun, and also from collisions between asteroids in the belt between Mars and Jupiter. Current estimates of the magnitude of the cosmic dust input rate into the Earth's atmosphere range from 2 to well over 100 tons per day, depending on whether the measurements are made in space, in the middle atmosphere, or at the surface in polar ice cores. This nearly 2 order-of-magnitude discrepancy indicates that there are serious flaws in the interpretation of observations that have been used to make the estimates. Dust particles enter the atmosphere at hyperthermal velocities (11 - 72 km s ^{-1}), and mostly ablate at heights between 80 and 120 km in a region of the atmosphere known as the mesosphere/lower thermosphere (MLT). The resulting metal vapours (Fe, Mg, Si and Na etc.) then oxidize and recondense to form nm-size particles, termed "meteoric smoke". These particles are too small to sediment downwards. Instead, they are transported by the general circulation of the atmosphere, taking roughly 5 years to reach the surface. There is great interest in the role smoke particles play as condensation nuclei of noctilucent ice clouds in the mesosphere, and polar stratospheric clouds in the lower stratosphere. Various new estimates of the dust input will be discussed. The first is from a zodiacal dust cloud model which predicts that more than 90% of the dust entering the atmosphere comes from Jupiter Family Comets; this model is constrained by observations of the zodiacal cloud using the IRAS, COBE and Planck satellites. The cometary dust is predicted to mostly be in a near-prograde orbit, entering the atmosphere with an average velocity around 14 km s ^{-1}. The total dust input should then be about 40 t d ^{-1}. However, relatively few of these particles are observed, even by the powerful Arecibo 430 MHz radar. Coupled models of meteoroid differential ablation, ionization and radar detection can be used to compute the probability of detecting a specified meteoroid in the Arecibo beam; an upper limit to the cosmic dust input of 16 t d ^{-1} has been obtained from the radar observations. Underpinning this modelling work is a novel laboratory experiment at the University of Leeds, where a novel Meteor Ablation Simulator is used to study the evaporation of metals from cosmic dust particles that are flash heated to over 3000 K. Finally, rocket-borne measurements of charged meteoric smoke particles indicate that about 5 t d ^{-1} of this cosmic dust ablates in the atmosphere, and another 6 t d ^{-1} fall to the surface as cosmic spherules.
NASA Technical Reports Server (NTRS)
Cane, H. V.; Richardson, I. G.; Vonrosenvinge, T. T.
1992-01-01
The time histories of particles in the energy range 1 MeV to 1 GeV at times of all greater than 3 percent cosmic ray decreases in the years 1978 to 1982 are studied. Essentially all 59 of the decreases commenced at or before the passages of interplanetary shocks, the majority of which accelerated energetic particles. We use the intensity-time profiles of the energetic particles to separate the cosmic ray decreases into four classes which we subsequently associate with four types of solar wind structures. Decreases in class 1 (15 events) and class 2 (26 events) can be associated with shocks which are driven by energetic coronal mass ejections. For class 1 events the ejecta is detected at 1 AU whereas this is not the case for class 2 events. The shock must therefore play a dominant role in producing the depression of cosmic rays in class 2 events. In all class 1 and 2 events (which comprise 69 percent of the total) the departure time of the ejection from the sun (and hence the location) can be determined from the rapid onset of energetic particles several days before the shock passage at Earth. The class 1 events originate from within 50 deg of central meridian. Class 3 events (10 decreases) can be attributed to less energetic ejections which are directed towards the Earth. In these events the ejecta is more important than the shock in causing a depression in the cosmic ray intensity. The remaining events (14 percent of the total) can be attributed to corotating streams which have ejecta material embedded in them.
NASA Astrophysics Data System (ADS)
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)
Cosmic censorship conjecture in Kerr-Sen black hole
NASA Astrophysics Data System (ADS)
Gwak, Bogeun
2017-06-01
The validity of the cosmic censorship conjecture for the Kerr-Sen black hole, which is a solution to the low-energy effective field theory for four-dimensional heterotic string theory, is investigated using charged particle absorption. When the black hole absorbs the particle, the charge on it changes owing to the conserved quantities of the particle. Changes in the black hole are constrained to the equation for the motion of the particle and are consistent with the laws of thermodynamics. Particle absorption increases the mass of the Kerr-Sen black hole to more than that of the absorbed charges such as angular momentum and electric charge; hence, the black hole cannot be overcharged. In the near-extremal black hole, we observe a violation of the cosmic censorship conjecture for the angular momentum in the first order of expansion and the electric charge in the second order. However, considering an adiabatic process carrying the conserved quantities as those of the black hole, we prove the stability of the black hole horizon. Thus, we resolve the violation. This is consistent with the third law of thermodynamics.
Influence of Sun and Other Cosmic Factors on Environment of the Earth
2010-01-07
of the secondary cosmic rays (mostly muons , electrons, neutrons and gammas) can provide highly cost-effective information on the key characteristics...Coronal mass ejection (CME) from the Sun the impact on the Galactic Cosmic rays (GCR) will be observed. Particle detector is vital for measuring the...modulation effects the sun poses on the ambient population of the Galactic Cosmic Rays (GCR). The known agents of these modulation effects are Solar Flares
Compact cosmic ray detector for unattended atmospheric ionization monitoring
NASA Astrophysics Data System (ADS)
Aplin, K. L.; Harrison, R. G.
2010-12-01
Two vertical cosmic ray telescopes for atmospheric cosmic ray ionization event detection are compared. Counter A, designed for low power remote use, was deployed in the Welsh mountains; its event rate increased with altitude as expected from atmospheric cosmic ray absorption. Independently, Counter B's event rate was found to vary with incoming particle acceptance angle. Simultaneous co-located comparison of both telescopes exposed to atmospheric ionization showed a linear relationship between their event rates.
NASA Astrophysics Data System (ADS)
Gusev, G. A.; Lomonosov, B. N.; Ryabov, Vladimir A.; Chechin, V. A.
2010-12-01
The problem of detecting nature's most energetic particles—cosmic rays and neutrinos—is reviewed. Prospects for using orbital radio detectors for these highest-energy particles are examined. Apertures are calculated for space experiments using the Moon and similar-sized ice satellites of planets of the Solar System as targets for the interaction of cosmic-ray particles and neutrinos. A comparative analysis shows that using the Moon as a target is the most promising scenario.
Particle acceleration, transport and turbulence in cosmic and heliospheric physics
NASA Technical Reports Server (NTRS)
Matthaeus, W.
1992-01-01
In this progress report, the long term goals, recent scientific progress, and organizational activities are described. The scientific focus of this annual report is in three areas: first, the physics of particle acceleration and transport, including heliospheric modulation and transport, shock acceleration and galactic propagation and reacceleration of cosmic rays; second, the development of theories of the interaction of turbulence and large scale plasma and magnetic field structures, as in winds and shocks; third, the elucidation of the nature of magnetohydrodynamic turbulence processes and the role such turbulence processes might play in heliospheric, galactic, cosmic ray physics, and other space physics applications.
The cosmic ray spectrum above 10(19) EV at Volcano Ranch and Haverah Park
NASA Technical Reports Server (NTRS)
Linsley, J.
1986-01-01
The cosmic ray energy per particle spectrum above 10 to the 19th power eV is measured the same way that energy spectra are measured at much lower energies, by counting all of the particles in a specified energy range that are incident per unit time with trajectories within specified geometrical limits. Difficulties with background or poorly known detection efficiency are markedly less than in some other cosmic ray measurements. The fraction of primary energy given to muons, neutrinos, and slow hadrons is less than 10% in this region, so the primary energy equals the track length integral of the secondary electrons with only a small correction for the energy given to other kinds of particles. Results from Volcano Ranch and Haverah Park are compared with results from the Yakutsk experiment.
NASA Technical Reports Server (NTRS)
Gronoff, Guillaume; Norman, Ryan B.; Mertens, Christopher J.
2014-01-01
The ability to evaluate the cosmic ray environment at Mars is of interest for future manned exploration. To support exploration, tools must be developed to accurately access the radiation environment in both free space and on planetary surfaces. The primary tool NASA uses to quantify radiation exposure behind shielding materials is the space radiation transport code, HZETRN. In order to build confidence in HZETRN, code benchmarking against Monte Carlo radiation transport codes is often used. This work compares the dose calculations at Mars by HZETRN and the Geant4 application Planetocosmics. The dose at ground and the energy deposited in the atmosphere by galactic cosmic ray protons and alpha particles has been calculated for the Curiosity landing conditions. In addition, this work has considered Solar Energetic Particle events, allowing for the comparison of varying input radiation environments. The results for protons and alpha particles show very good agreement between HZETRN and Planetocosmics.
Long term variability of the cosmic ray intensity
NASA Technical Reports Server (NTRS)
Bhat, C. L.; Houston, B. P.; Mayer, C. J.; Wolfendale, A. W.
1985-01-01
In a previous paper Bhat, et al., assess the evidence for the continuing acceleration of cosmic rays in the Loop I supernova remnant. The enhanced gamma-ray emission is found consistent with the Blandford and Cowie model for particle acceleration at the remnant shock wave. The contributions of other supernovae remnants to the galactic cosmic ray energy density are now considered, paying anisotropy of cosmic rays accelerated by local supernovae ( 100 pc). The results are compared with geophysical data on the fluctuations in the cosmic ray intensity over the previous one billion years.
Testing the weak gravity-cosmic censorship connection
NASA Astrophysics Data System (ADS)
Crisford, Toby; Horowitz, Gary T.; Santos, Jorge E.
2018-03-01
A surprising connection between the weak gravity conjecture and cosmic censorship has recently been proposed. In particular, it was argued that a promising class of counterexamples to cosmic censorship in four-dimensional Einstein-Maxwell-Λ theory would be removed if charged particles (with sufficient charge) were present. We test this idea and find that indeed if the weak gravity conjecture is true, one cannot violate cosmic censorship this way. Remarkably, the minimum value of charge required to preserve cosmic censorship appears to agree precisely with that proposed by the weak gravity conjecture.
Real-Time Penetrating Particle Analyzer (PAN)
NASA Astrophysics Data System (ADS)
Wu, X.; Ambrosi, G.; Bertucci, B.
2018-02-01
The PAN can measure penetrating particles with great precision to study energetic particles, solar activities, and the origin and propagation of cosmic rays. The real-time monitoring of penetrating particles is crucial for deep space human travel.
NASA Astrophysics Data System (ADS)
Kudryavtsev, I. V.; Jungner, H.
2011-10-01
The possible mechanism by which cosmic rays affect the formation of neutral water droplets and ice crystals in the Earth's atmosphere has been considered. This mechanism is based on changes in atmospheric transparency and vertical temperature distribution. It has been indicated that a change in the optical thickness for visible and IR radiation by several percents, which can take place when cosmic-ray particles penetrate into the atmosphere, results in a change in the temperature vertical distribution, affecting the growth of water droplets, concentration of active condensation nuclei, and the formation of ice particles. This mechanism makes it possible to explain the correlation between the intensity of galactic cosmic rays at low altitudes and the absence of this correlation at middle altitudes.
Montanino, Daniele; Vazza, Franco; Mirizzi, Alessandro; Viel, Matteo
2017-09-08
Large-scale extragalactic magnetic fields may induce conversions between very-high-energy photons and axionlike particles (ALPs), thereby shielding the photons from absorption on the extragalactic background light. However, in simplified "cell" models, used so far to represent extragalactic magnetic fields, this mechanism would be strongly suppressed by current astrophysical bounds. Here we consider a recent model of extragalactic magnetic fields obtained from large-scale cosmological simulations. Such simulated magnetic fields would have large enhancement in the filaments of matter. As a result, photon-ALP conversions would produce a significant spectral hardening for cosmic TeV photons. This effect would be probed with the upcoming Cherenkov Telescope Array detector. This possible detection would give a unique chance to perform a tomography of the magnetized cosmic web with ALPs.
Research in particle and gamma-ray astrophysics
NASA Technical Reports Server (NTRS)
Stone, E. C.; Davis, L., Jr.; Mewaldt, R. A.; Prince, T. A.
1988-01-01
Research activities in cosmic rays, gamma rays, and astrophysical plasmas are covered. Each activity is described, followed by a bibliography. The research program is directed toward the investigation of the astrophysical aspects of cosmic rays and gamma rays and of the radiation and electromagnetic field environment of the earth and other planets. These investigations were performed by means of energetic particle and photon detector systems flown on spacecraft and balloons.
COSMIC-RAY SMALL-SCALE ANISOTROPIES AND LOCAL TURBULENT MAGNETIC FIELDS
DOE Office of Scientific and Technical Information (OSTI.GOV)
López-Barquero, V.; Farber, R.; Xu, S.
2016-10-10
Cosmic-ray anisotropy has been observed in a wide energy range and at different angular scales by a variety of experiments over the past decade. However, no comprehensive or satisfactory explanation has been put forth to date. The arrival distribution of cosmic rays at Earth is the convolution of the distribution of their sources and of the effects of geometry and properties of the magnetic field through which particles propagate. It is generally believed that the anisotropy topology at the largest angular scale is adiabatically shaped by diffusion in the structured interstellar magnetic field. On the contrary, the medium- and small-scalemore » angular structure could be an effect of nondiffusive propagation of cosmic rays in perturbed magnetic fields. In particular, a possible explanation for the observed small-scale anisotropy observed at the TeV energy scale may be the effect of particle propagation in turbulent magnetized plasmas. We perform numerical integration of test particle trajectories in low- β compressible magnetohydrodynamic turbulence to study how the cosmic rays’ arrival direction distribution is perturbed when they stream along the local turbulent magnetic field. We utilize Liouville’s theorem for obtaining the anisotropy at Earth and provide the theoretical framework for the application of the theorem in the specific case of cosmic-ray arrival distribution. In this work, we discuss the effects on the anisotropy arising from propagation in this inhomogeneous and turbulent interstellar magnetic field.« less
NASA Technical Reports Server (NTRS)
Flynn, G. J.; Sutton, S. R.
1990-01-01
Trace element abundance determinations were performed using synchrotron X-ray fluorescence on nine particles collected from the stratosphere and classified as cosmic. Improvements to the Synchrotron Light Source allowed the detection of all elements between Cr and Mo, with the exceptions of Co and As, in our largest particle. The minor and trace element abundance patterns of three Ni-depleted particles were remarkably similar to those of extraterrestrial igneous rocks. Fe/Ni and Fe/Mn ratios suggest that one of these may be of lunar origin. All nine particles exhibited an enrichment in Br, ranging from 1.3 to 38 times the C1 concentration. Br concentrations were uncorrelated with particle size, as would be expected for a surface correlated component acquires from the stratosphere.
NASA Astrophysics Data System (ADS)
Bazhutov, Yu. N.
2001-08-01
It is discussed the interpretation of negative penetrating cosmic ray particles excess flux observed in bubble chamber "SKAT" for the momentum range P > P0 = 30 GeV/c by Erzions, hypothetical heavy stable penetrating hadrons, proposed to explain the anomalous vertical muons energy spectrum at small depth underground. Here it is shown that negative charge of p articles observed in "SKAT" is the same as predicted by theoretical Erzion model. The excess particles flux ( J ˜ 10-5 cm-2 s-1 sr-1 ) corresponds to the Erzion intensity observed by scintillation telescope in our previous experiment. The threshold momentum ( P0 ) and the track length threshold ( L0 = 50 cm of liquid BrF3C) are in good accordance with Erzion stop path as for the single charged particle with mass M ≅ 200 GeV/c2 . But to don't contradict with all previous charge ratio results for cosmic ray muons in 30 - 100 GeV/c momentum range it is necessary to propose for such particles the Solar sporadic origin taking to account that both Erzion observations were in the active Sun years (April 23,1979 & July, 1999). INTRODUCTION. 20 years ago to explain anomalous energy spectrum of vertical cosmic ray muons, observed at sea level and small depth underground (<100 m.w.e.) [1,2], it was proposed hypothesis of existing in cosmic rays new heavy stable penetrating hadrons [3]. From that time our experiments to search such particles were started [4,5,6]. Later the theoretical model U(1)xSUl(2)xSU r(2)xSU(3) of such particles (Erzions) has been created in framework of "mirror" models [7,8], which without contradictions to elementary particles Standard Model has explained large kind of another anomalous results in cosmic rays and nuclear physics [9-19]. At last after almost 20 years Erzions search they have been observed due to small vertical original scintillation telescope "Doch-4" [20,21,22]. The observed Erz ions mass was ME = (175+/-25) GeV/c2 and intensity at sea level - JE = (1.8+/-0.4)ṡ10-6 cm-2 sr-1 s-1 (at EE ≤ 6 GeV, PE ≤ 50 GeV/c2 ). To confirm such Erzion discovery it was undertook the attempt of Erzions search on one of the largest bubble chamber (BC) "SKAT", exposed 16 years (19761992) on the neutrino beam of Serpukhov Proton Accelerator.
Chemical characterization of seven Large Area Collector particles by SXRF. [cosmic dust composition
NASA Technical Reports Server (NTRS)
Flynn, G. J.; Sutton, S. R.
1991-01-01
Optical microscopy and synchrotron X-ray fluorescence (SXRF) are used to analyze the chemical composition of seven dark-appearing cosmic-dust particles obtained in the stratosphere during NASA Johnson Large Area Collector flights. The experimental setup and procedures are outlined, and the results are presented in extensive tables. Three of the particles had abundances similar to those of chondrites (except for low Ca values in one particle); two had a metallic appearance and spectra dominated by Fe and Zn; one contained Cu and Cr plus small amounts of Fe and Zn; and one had igneous-type abundances of minor and trace elements while containing all of the elements seen in chondritic particles, suggesting it may be of extraterrestrial origin.
NASA Astrophysics Data System (ADS)
Mishev, A. L.; Velinov, P. I. Y.
2014-12-01
In the last few years an essential progress in development of physical models for cosmic ray induced ionization in the atmosphere is achieved. The majority of these models are full target, i.e. based on Monte Carlo simulation of an electromagnetic-muon-nucleon cascade in the atmosphere. Basically, the contribution of proton nuclei is highlighted, i.e. the contribution of primary cosmic ray α-particles and heavy nuclei to the atmospheric ionization is neglected or scaled to protons. The development of cosmic ray induced atmospheric cascade is sensitive to the energy and mass of the primary cosmic ray particle. The largest uncertainties in Monte Carlo simulations of a cascade in the Earth atmosphere are due to assumed hadron interaction models, the so-called hadron generators. In the work presented here we compare the ionization yield functions Y for primary cosmic ray nuclei, such as α-particles, Oxygen and Iron nuclei, assuming different hadron interaction models. The computations are fulfilled with the CORSIKA 6.9 code using GHEISHA 2002, FLUKA 2011, UrQMD hadron generators for energy below 80 GeV/nucleon and QGSJET II for energy above 80 GeV/nucleon. The observed difference between hadron generators is widely discussed. The influence of different atmospheric parametrizations, namely US standard atmosphere, US standard atmosphere winter and summer profiles on ion production rate is studied. Assuming realistic primary cosmic ray mass composition, the ion production rate is obtained at several rigidity cut-offs - from 1 GV (high latitudes) to 15 GV (equatorial latitudes) using various hadron generators. The computations are compared with experimental data. A conclusion concerning the consistency of the hadron generators is stated.
Spaced-based Cosmic Ray Astrophysics
NASA Astrophysics Data System (ADS)
Seo, Eun-Suk
2016-03-01
The bulk of cosmic ray data has been obtained with great success by balloon-borne instruments, particularly with NASA's long duration flights over Antarctica. More recently, PAMELA on a Russian Satellite and AMS-02 on the International Space Station (ISS) started providing exciting measurements of particles and anti-particles with unprecedented precision upto TeV energies. In order to address open questions in cosmic ray astrophysics, future missions require spaceflight exposures for rare species, such as isotopes, ultra-heavy elements, and high (the ``knee'' and above) energies. Isotopic composition measurements up to about 10 GeV/nucleon that are critical for understanding interstellar propagation and origin of the elements are still to be accomplished. The cosmic ray composition in the knee (PeV) region holds a key to understanding the origin of cosmic rays. Just last year, the JAXA-led CALET ISS mission, and the DAMPE Chinese Satellite were launched. NASA's ISS-CREAM completed its final verification at GSFC, and was delivered to KSC to await launch on SpaceX. In addition, a EUSO-like mission for ultrahigh energy cosmic rays and an HNX-like mission for ultraheavy nuclei could accomplish a vision for a cosmic ray observatory in space. Strong support of NASA's Explorer Program category of payloads would be needed for completion of these missions over the next decade.
Nineteenth International Cosmic Ray Conference. HE Sessions, Volume 7
NASA Technical Reports Server (NTRS)
Jones, F. C. (Compiler)
1985-01-01
Papers submitted for presentation at the 19th International Cosmic ray Conference are compiled. This volume contains papers which address various aspects of extensive air showers (EAS) produced by energetic particles and gamma rays.
Radiation equivalent dose simulations for long-term interplanetary flights
NASA Astrophysics Data System (ADS)
Dobynde, M. I.; Drozdov, A.; Shprits, Y. Y.
2016-12-01
Cosmic particle radiation is a limiting factor for the human interplanetary flights. The unmanned flights inside heliosphere and human flights inside of magnetosphere tend to become a routine procedure, whereas there have been only few shot term human flights out of it (Apollo missions 1969-1972) with maximum duration less than a month. Long-term human flights set much higher requirements to the radiation shielding, primarily because of long exposition to cosmic radiation. Inside the helosphere there are two main sources of cosmic radiation: galactic cosmic rays (GCR) and soalr particle events (SPE). GCR come from the outside of heliosphere forming a background of overall radiation that affects the spacecraft. The intensity of GCR is varied according to solar activity, increasing with solar activity decrease and backward, with the modulation time (time between nearest maxima) of 11 yeas. SPE are shot term events, comparing to GCR modulation time, but particle fluxes are much more higher. The probability of SPE increases with the increase of solar activity. Time dependences of the intensity of these two components encourage looking for a time window of flight, when intensity and effect of GCR and SPE would be minimized. Combining GEANT4 Monte Carlo simulations with time dependent model of GCR spectra and data on SPE spectra we show the time dependence of the radiation dose in an anthropomorphic human phantom inside the shielding capsule. Different types of particles affect differently on the human providing more or less harm to the tissues. We use quality factors to recalculate absorbed dose into biological equivalent dose, which give more information about risks for astronaut's health. Incident particles provide a large amount of secondary particles while propagating through the shielding capsule. We try to find an optimal combination of shielding material and thickness, that will effectively decrease the incident particle energy, at the same time minimizing flow of secondary induced particles and minimizing most harmful particle types flows.
Cosmic radiation dose in aircraft--a neutron track etch detector.
Vuković, B; Radolić, V; Miklavcić, I; Poje, M; Varga, M; Planinić, J
2007-01-01
Cosmic radiation bombards us at high altitude by ionizing particles. The radiation environment is a complex mixture of charged particles of solar and galactic origin, as well as of secondary particles produced in interaction of the galactic cosmic particles with the nuclei of atmosphere of the Earth. The radiation field at aircraft altitude consists of different types of particles, mainly photons, electrons, positrons and neutrons, with a large energy range. The non-neutron component of cosmic radiation dose aboard ATR 42 and A 320 aircrafts (flight level of 8 and 11 km, respectively) was measured with TLD-100 (LiF:Mg,Ti) detectors and the Mini 6100 semiconductor dosimeter. The estimated occupational effective dose for the aircraft crew (A 320) working 500 h per year was 1.64 mSv. Other experiments, or dose rate measurements with the neutron dosimeter, consisting of LR-115 track detector and boron foil BN-1 or 10B converter, were performed on five intercontinental flights. Comparison of the dose rates of the non-neutron component (low LET) and the neutron one (high LET) of the radiation field at the aircraft flight level showed that the neutron component carried about 50% of the total dose. The dose rate measurements on the flights from the Middle Europe to the South and Middle America, then to Korea and Japan, showed that the flights over or near the equator region carried less dose rate; this was in accordance with the known geomagnetic latitude effect.
Observation of ultrahigh-energy cosmic rays and neutrinos from lunar orbit: LORD space experiment
NASA Astrophysics Data System (ADS)
Ryabov, Vladimir; Chechin, Valery; Gusev, German
The problem of detecting highest-energy cosmic rays and neutrinos in the Universe is reviewed. Nowadays, there becomes clear that observation of these particles requires approaches based on novel principles. Projects based on orbital radio detectors for particles of energies above the CZK cut-off are discussed. We imply the registration of coherent Cherenkov radio emission produced by cascades of most energetic particles in radio-transparent lunar regolith. The Luna-Glob space mission proposed for launching in the near future involves the Lunar Orbital Radio Detector (LORD). The feasibility of LORD space instrument to detect radio signals from cascades initiated by ultrahigh-energy particles interacting with lunar regolith is examined. The comprehensive Monte Carlo calculations were carried out within the energy range of 10 (20) -10 (25) eV with the account for physical properties of the Moon such as its density, the lunar-regolith radiation length, the radio-wave absorption length, the refraction index, and the orbital altitude of a lunar satellite. We may expect that the LORD space experiment will surpass in its apertures and capabilities the majority of well-known current and proposed experiments dealing with the detection of both ultrahigh-energy cosmic rays and neutrinos. The design of the LORD space instrument and its scientific potentialities in registration of low-intense cosmic-ray particle fluxes above the GZK cut-off up to 10 (25) eV is discussed as well. The designed LORD module (including an antenna system, amplifiers, and a data acquisition system) now is under construction. The LORD space experiment will make it possible to obtain important information on the highest-energy particles in the Universe, to verify modern models for the origin and the propagation of ultrahigh-energy cosmic rays and neutrinos. Successful completion of the LORD experiment will permit to consider the next step of the program, namely, a multi-satellite lunar systems to increase the statistics and the accuracy of the experiment. Opportunities and prospects of a multi-satellite system for observation of ultrahigh-energy cosmic rays and neutrinos are also investigated. In addition, possibilities of future missions to Jovian satellites are analyzed, insofar as the largest ice planets of the Solar System (Ganymede and Europe) can be considered as convenient targets for registration of ultrahigh-energy particles by orbiting radio detectors. The expected results are compared to those for the lunar target. The conclusion is made that within the Solar System, there are no objects with better registration efficiency for ultrahigh-energy cosmic rays and neutrinos that can be utilized in space experiments of as an alternative to the future space mission Luna-Glob with the LORD orbital radio detector.
Pulsar Wind Nebulae inside Supernova Remnants as Cosmic-Ray PeVatrons
NASA Astrophysics Data System (ADS)
Ohira, Yutaka; Kisaka, Shota; Yamazaki, Ryo
2018-07-01
We propose that cosmic ray PeVatrons are pulsar wind nebulae (PWNe) inside supernova remnants (SNRs). The PWN initially expands into the freely expanding stellar ejecta. Then, the PWN catches up with the shocked region of the SNR, where particles can be slightly accelerated by the back and forth motion between the PWN and the SNR, and some particles diffuse into the PWN. Afterwards the PWN is compressed by the SNR, where the particles in the PWN are accelerated by the adiabatic compression. Using a Monte Carlo simulation, we show that particles accelerated by the SNR to 0.1 PeV can be reaccelerated to 1 PeV until the end of the PWN compression.
Pulsar Wind Nebulae inside Supernova Remnants as Cosmic-Ray PeVatrons
NASA Astrophysics Data System (ADS)
Ohira, Yutaka; Kisaka, Shota; Yamazaki, Ryo
2018-05-01
We propose that cosmic-ray PeVatrons are pulsar wind nebulae (PWNe) inside supernova remnants (SNRs). The PWN initially expands into the freely expanding stellar ejecta. Then, the PWN catches up with the shocked region of the SNR, where particles can be slightly accelerated by the back and forth motion between the PWN and the SNR, and some particles diffuse into the PWN. Afterwards the PWN is compressed by the SNR, where the particles in the PWN are accelerated by the adiabatic compression. Using a Monte Carlo simulation, we show that particles accelerated by the SNR to 0.1 PeV can be reaccelerated to 1 PeV until the end of the PWN compression.
Laboratory laser acceleration and high energy astrophysics: {gamma}-ray bursts and cosmic rays
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tajima, T.; Takahashi, Y.
1998-08-20
Recent experimental progress in laser acceleration of charged particles (electrons) and its associated processes has shown that intense electromagnetic pulses can promptly accelerate charged particles to high energies and that their energy spectrum is quite hard. On the other hand some of the high energy astrophysical phenomena such as extremely high energy cosmic rays and energetic components of {gamma}-ray bursts cry for new physical mechanisms for promptly accelerating particles to high energies. The authors suggest that the basic physics involved in laser acceleration experiments sheds light on some of the underlying mechanisms and their energy spectral characteristics of the promptlymore » accelerated particles in these high energy astrophysical phenomena.« less
Ultrahigh-energy cosmic rays: physics and astrophysics at extreme energies.
Sigl, G
2001-01-05
The origin of cosmic rays is one of the major unresolved questions in astrophysics. In particular, the highest energy cosmic rays observed have macroscopic energies up to several 10(20) electron volts and thus provide a probe of physics and astrophysics at energies unattained in laboratory experiments. Theoretical explanations range from astrophysical acceleration of charged particles, to particle physics beyond the established standard model, and processes taking place at the earliest moments of our universe. Distinguishing between these scenarios requires detectors with effective areas in the 1000-square-kilometer range, which are now under construction or in the planning stage. Close connections with gamma-ray and neutrino astrophysics add to the interdisciplinary character of this field.
The Track Imaging Cerenkov Experiment
NASA Technical Reports Server (NTRS)
Wissel, S. A.; Byrum, K.; Cunningham, J. D.; Drake, G.; Hays, E.; Horan, D.; Kieda, D.; Kovacs, E.; Magill, S.; Nodulman, L.;
2011-01-01
We describe a. dedicated cosmic-ray telescope that explores a new method for detecting Cerenkov radiation from high-energy primary cosmic rays and the large particle air shower they induce upon entering the atmosphere. Using a camera comprising 16 multi-anode photomultiplier tubes for a total of 256 pixels, the Track Imaging Cerenkov Experiment (TrICE) resolves substructures in particle air showers with 0,086 deg resolution. Cerenkov radiation is imaged using a novel two-part optical system in which a Fresnel lens provides a wide-field optical trigger and a mirror system collects delayed light with four times the magnification. TrICE records well-resolved cosmic-ray air showers at rates ranging between 0.01-0.1 Hz.
Hu, Ping-Kai; Kusenko, Alexander; Takhistov, Volodymyr
2017-02-22
If dark matter particles have an electric charge, as in models of millicharged dark matter, such particles should be accelerated in the same astrophysical accelerators that produce ordinary cosmic rays, and their spectra should have a predictable rigidity dependence. Depending on the charge, the resulting “dark cosmic rays” can be detected as muon-like or neutrino-like events in Super-Kamiokande, IceCube, and other detectors. We present new limits and propose several new analyses, in particular, for the Super-Kamiokande experiment, which can probe a previously unexplored portion of the millicharged dark matter parameter space. Here, most of our results are fairly general andmore » apply to a broad class of dark matter models.« less
Numerical Simulation of the Anomalous Transport of High-Energy Cosmic Rays in Galactic Superbubble
NASA Technical Reports Server (NTRS)
Barghouty, A. F.; Price, E. M.; MeWaldt, R. A.
2013-01-01
A continuous-time random-walk (CTRW) model to simulate the transport and acceleration of high-energy cosmic rays in galactic superbubbles has recently been put forward (Barghouty & Schnee 2102). The new model has been developed to simulate and highlight signatures of anomalous transport on particles' evolution and their spectra in a multi-shock, collective acceleration context. The superbubble is idealized as a heterogeneous region of particle sources and sinks bounded by a random surface. This work concentrates on the effects of the bubble's assumed astrophysical characteristics (cf. geometry and roughness) on the particles' spectra.
Investigating the origin of ultrahigh-energy cosmic rays with CRPropa
NASA Astrophysics Data System (ADS)
Bouchachi, Dallel; Attallah, Reda
2016-07-01
Ultrahigh-energy cosmic rays are the most energetic of any subatomic particles ever observed in nature. Yet, their sources and acceleration mechanisms are still unknown. To better understand the origin of these particles, we carried out extensive numerical simulations of their propagation in extragalactic space. We used the public CRPropa code which considers all relevant particle interactions and magnetic deflections. We examined the energy spectrum, the mass composition, and the distribution of arrival directions under different scenarios. Such a study allows, in particular, to properly interpret the data of modern experiments like "The Pierre Auger Observatory" and "The Telescope Array".
An interpretation of the observed oxygen and nitrogen enhancements in low-energy cosmic rays
NASA Technical Reports Server (NTRS)
Fisk, L. A.; Ramaty, R.; Kozlovsky, B.
1974-01-01
The possibility is suggested that the enhancement of cosmic-ray oxygen and nitrogen observed at about 10 MeV per nucleon could result from neutral interstellar particles that are swept into the solar cavity by the motion of the sun through the interstellar medium. These particles are subsequently ionized and accelerated. It is pointed out that this mechanism imposes no severe requirements either on the number of particles that have to be accelerated or on the energy that has to be removed from the solar wind to perform this acceleration.
Radio detection of cosmic-ray air showers and high-energy neutrinos
NASA Astrophysics Data System (ADS)
Schröder, Frank G.
2017-03-01
In the last fifteen years radio detection made it back to the list of promising techniques for extensive air showers, firstly, due to the installation and successful operation of digital radio experiments and, secondly, due to the quantitative understanding of the radio emission from atmospheric particle cascades. The radio technique has an energy threshold of about 100 PeV, which coincides with the energy at which a transition from the highest-energy galactic sources to the even more energetic extragalactic cosmic rays is assumed. Thus, radio detectors are particularly useful to study the highest-energy galactic particles and ultra-high-energy extragalactic particles of all types. Recent measurements by various antenna arrays like LOPES, CODALEMA, AERA, LOFAR, Tunka-Rex, and others have shown that radio measurements can compete in precision with other established techniques, in particular for the arrival direction, the energy, and the position of the shower maximum, which is one of the best estimators for the composition of the primary cosmic rays. The scientific potential of the radio technique seems to be maximum in combination with particle detectors, because this combination of complementary detectors can significantly increase the total accuracy for air-shower measurements. This increase in accuracy is crucial for a better separation of different primary particles, like gamma-ray photons, neutrinos, or different types of nuclei, because showers initiated by these particles differ in average depth of the shower maximum and in the ratio between the amplitude of the radio signal and the number of muons. In addition to air-shower measurements, the radio technique can be used to measure particle cascades in dense media, which is a promising technique for detection of ultra-high-energy neutrinos. Several pioneering experiments like ARA, ARIANNA, and ANITA are currently searching for the radio emission by neutrino-induced particle cascades in ice. In the next years these two sub-fields of radio detection of cascades in air and in dense media will likely merge, because several future projects aim at the simultaneous detection of both, high-energy cosmic-rays and neutrinos. SKA will search for neutrino and cosmic-ray initiated cascades in the lunar regolith and simultaneously provide unprecedented detail for air-shower measurements. Moreover, detectors with huge exposure like GRAND, SWORD or EVA are being considered to study the highest energy cosmic rays and neutrinos. This review provides an introduction to the physics of radio emission by particle cascades, an overview on the various experiments and their instrumental properties, and a summary of methods for reconstructing the most important air-shower properties from radio measurements. Finally, potential applications of the radio technique in high-energy astroparticle physics are discussed.
Non-linear acceleration at supernova remnant shocks and the hardening in the cosmic ray spectrum
NASA Astrophysics Data System (ADS)
Recchia, S.; Gabici, S.
2018-02-01
In the last few years, several experiments have shown that the cosmic ray spectrum below the knee is not a perfect power law. In particular, the proton and helium spectra show a spectral hardening by ˜0.1-0.2 in spectral index at particle energies of ˜ 200-300 GeV nucleon-1. Moreover, the helium spectrum is found to be harder than that of protons by ˜0.1 and some evidence for a similar hardening was also found in the spectra of heavier elements. Here, we consider the possibility that the hardening may be the result of a dispersion in the slope of the spectrum of cosmic rays accelerated at supernova remnant shocks. Such a dispersion is indeed expected within the framework of non-linear theories of diffusive shock acceleration, which predict steeper (harder) particle spectra for larger (smaller) cosmic ray acceleration efficiencies.
Cosmic ray injection spectrum at the galactic sources
NASA Astrophysics Data System (ADS)
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.
Solar-flare-induced Forbush decreases - Dependence on shock wave geometry
NASA Technical Reports Server (NTRS)
Thomas, B. T.; Gall, R.
1984-01-01
It is argued that the principal mechanism for the association of Forbush decreases with the passage of a solar flare shock wave is prolonged containment of cosmic ray particles behind the flare compression region, which acts as a semipermeable obstacle to particle motion along the field lines, leading to additional adiabatic cooling of the particles. Liouville's theorem is used to calculate the instantaneous distribution function at 1 AU for each particle arriving at the earth. By averaging over a large number of individual estimates, a representative estimate of the omnidirectional phase space density and the corresponding particle intensity is obtained. The energy change of individual particles at the shocks is found to be small in comparison to the energy lost by adiabatic cooling of the cosmic rays between the shock wave and the sun. The effects of particle rigidity, diffusion coefficient, and flare longitude on the magnitude of the Forbush decrease are quantitatively investigated.
Study of cosmic dust particles on board LDEF: The FRECOPA experiments AO138-1 and AO138-2
NASA Technical Reports Server (NTRS)
Mandeville, J. C.; Borg, Janet
1992-01-01
Two experiments, within the French Cooperative Payload (FRECOPA) and devoted to the detection of cosmic dust, were flown on the LDEF. A variety of sensors and collecting devices have made possible the study of impact processes on materials of technological interest. Preliminary examination of hypervelocity impact features gives valuable data on size distribution and nature of interplanetary dust particles in low earth orbit, within the 0.5 to 300 micrometer size range. Most of the events detected on the trailing face of LDEF are expected to be the result of impacts of meteoritic particles only. So far, chemical analysis of craters by EDS clearly shows evidence of elements (Na, Mg, Si, S, Ca, and Fe) consistent with cosmic origin. Systematic occurrence of C and O in crater residues is an important result, to be compared with the existence of CHON particles detected in P-Halley comet nucleus. Crater size distribution is in good agreement with results from other dust experiments flown on LDEF. However, no crater smaller than 1.5 micron was observed, thus suggesting a cutoff in the near earth particle distribution. Possible origin and orbital evolution of micrometeoroids is discussed.
The Determination of the Muon Magnetic Moment from Cosmic Rays
ERIC Educational Resources Information Center
Amsler, C.
1974-01-01
Describes an experiment suited for use in an advanced laboratory course in particle physics. The magnetic moment of cosmic ray muons which have some polarization is determined with an error of about five percent. (Author/GS)
NASA Technical Reports Server (NTRS)
Koontz, Steve
2015-01-01
In this presentation a review of galactic cosmic ray (GCR) effects on microelectronic systems and human health and safety is given. The methods used to evaluate and mitigate unwanted cosmic ray effects in ground-based, atmospheric flight, and space flight environments are also reviewed. However not all GCR effects are undesirable. We will also briefly review how observation and analysis of GCR interactions with planetary atmospheres and surfaces and reveal important compositional and geophysical data on earth and elsewhere. About 1000 GCR particles enter every square meter of Earth’s upper atmosphere every second, roughly the same number striking every square meter of the International Space Station (ISS) and every other low- Earth orbit spacecraft. GCR particles are high energy ionized atomic nuclei (90% protons, 9% alpha particles, 1% heavier nuclei) traveling very close to the speed of light. The GCR particle flux is even higher in interplanetary space because the geomagnetic field provides some limited magnetic shielding. Collisions of GCR particles with atomic nuclei in planetary atmospheres and/or regolith as well as spacecraft materials produce nuclear reactions and energetic/highly penetrating secondary particle showers. Three twentieth century technology developments have driven an ongoing evolution of basic cosmic ray science into a set of practical engineering tools needed to design, test, and verify the safety and reliability of modern complex technological systems and assess effects on human health and safety effects. The key technology developments are: 1) high altitude commercial and military aircraft; 2) manned and unmanned spacecraft; and 3) increasingly complex and sensitive solid state micro-electronics systems. Space and geophysical exploration needs drove the development of the instruments and analytical tools needed to recover compositional and structural data from GCR induced nuclear reactions and secondary particle showers. Finally, the possible role of GCR secondary particle showers in addressing an important homeland security problem, finding nuclear contraband and weapons, will be briefly reviewed.
Silica Aerogel Captures Cosmic Dust Intact
NASA Technical Reports Server (NTRS)
Tsou, P.
1994-01-01
The mesostructure of silica aerogel resembles stings of grapes, ranging in size from 10 to 100 angstrom. This fine mesostructure transmits nearly 90 percent of incident light in the visible, while providing sufficiently gentle dissipation of the kinetric energy of hypervelocity cosmic dust particles to permit their intact capture. We introduced silica aerogel in 1987 as capture medium to take advantage of its low density, fine mesostruicture and most importantly, its transparency, allowing optical location of captured micron sized particles.
Searching for Dark Matter with Cosmic Rays
NASA Astrophysics Data System (ADS)
Seo, Eun-Suk
2015-04-01
One of the most exciting possibilities in cosmic ray research is the potential to discover new phenomena. A number of elementary particles were discovered in cosmic rays before modern-day accelerators became available to study their detailed properties. Since the discovery of cosmic ray antiprotons in 1979 using a balloon-borne magnet spectrometer, a series of magnet spectrometers have been flown to search for the signature of dark matter annihilation in antiprotons and positrons. Being the same as particles except for their opposite charge sign, antiparticles are readily distinguished as they bend in opposite directions in the magnetic field. As long-duration balloon flights over Antarctica became available, not only antiproton to proton ratios but also measurements of antiproton energy spectra became possible. More recently, space missions are also providing precision measurements of electron and position energy spectra. With other measurements to constrain cosmic ray propagation models, these new measurements play key roles in constraining dark-matter models for understanding the nature of dark matter. Recent results, their implications, and outlook for the field will be presented.
Linking high-energy cosmic particles by black-hole jets embedded in large-scale structures
NASA Astrophysics Data System (ADS)
Fang, Ke; Murase, Kohta
2018-04-01
The origin of ultrahigh-energy cosmic rays (UHECRs) is a half-century-old enigma1. The mystery has been deepened by an intriguing coincidence: over ten orders of magnitude in energy, the energy generation rates of UHECRs, PeV neutrinos and isotropic sub-TeV γ-rays are comparable, which hints at a grand unified picture2. Here we report that powerful black hole jets in aggregates of galaxies can supply the common origin for all of these phenomena. Once accelerated by a jet, low-energy cosmic rays confined in the radio lobe are adiabatically cooled; higher-energy cosmic rays leaving the source interact with the magnetized cluster environment and produce neutrinos and γ-rays; the highest-energy particles escape from the host cluster and contribute to the observed cosmic rays above 100 PeV. The model is consistent with the spectrum, composition and isotropy of the observed UHECRs, and also explains the IceCube neutrinos and the non-blazar component of the Fermi γ-ray background, assuming a reasonable energy output from black hole jets in clusters.
Research in cosmic and gamma ray astrophysics
NASA Technical Reports Server (NTRS)
Stone, E. C.; Davis, L., Jr.; Mewaldt, R. A.; Prince, T. A.
1989-01-01
Research activities in cosmic rays, gamma rays, and astrophysical plasmas are covered. The activities are divided into sections and described, followed by a bibliography. The astrophysical aspects of cosmic rays, gamma rays, and of the radiation and electromagnetic field environment of the Earth and other planets are investigated. These investigations are performed by means of energetic particle and photon detector systems flown on spacecraft and balloons.
Neutron and antineutron production in accretion onto compact objects
NASA Technical Reports Server (NTRS)
Dermer, C. D.; Ramaty, R.
1986-01-01
Nuclear reactions in the hot accretion plasma surrounding a collapsed star are a source of neutrons, primarily through spallation and pion-producing reactions, and antineutrons, principally through the reaction p+p yields p+p+n+anti-n. We calculate spectra of neutrons and antineutrons produced by a variety of nonthermal energetic particle distributions in which the target particles are either at rest or in motion. If only neutral particles are free to escape the interaction site, a component of the proton and antiproton fluxes in the cosmic radiation results from the neutrons and antineutrons which leave the accretion plasma and subsequently decay in the interstellar medium. This additional antiproton component could account for the enhanced flux of antiprotons in the cosmic radiation, compared to values expected from the standard leaky-box model of cosmic-ray propagation and confinement. Moreover, the low-energy antiproton flux measured by Buffington et al. (1981) could result from target-particle motion in the accretion plasma. This model for the origin of antiprotons predicts a narrow 2.223 MeV line which could be observable.
The UCSD high energy X-ray timing experiment cosmic ray particle anticoincidence detector
NASA Technical Reports Server (NTRS)
Hink, P. L.; Rothschild, R. E.; Pelling, M. R.; Macdonald, D. R.; Gruber, D. E.
1991-01-01
The HEXTE, part of the X-Ray Timing Explorer (XTE), is designed to make high sensitivity temporal and spectral measurements of X-rays with energies between 15 and 250 keV using NaI/CsI phoswich scintillation counters. To achieve the required sensitivity it is necessary to provide anticoincidence of charged cosmic ray particles incident upon the instrument, some of which interact to produce background X-rays. The proposed cosmic ray particle anticoincidence shield detector for HEXTE uses a novel design based on plastic scintillators and wavelength-shifter bars. It consists of five segments, each with a 7 mm thick plastic scintillator, roughly 50 cm x 50 cm in size, coupled to two wavelength-shifter bars viewed by 1/2 inch photomultiplier tubes. These segments are configured into a five-sided, box-like structure around the main detector system. Results of laboratory testing of a model segment, and calculations of the expected performance of the flight segments and particle anticoincidence detector system are presented to demonstrate that the above anticoincidence detector system satisfies its scientific requirements.
DNDO Report: Predicting Solar Modulation Potentials for Modeling Cosmic Background Radiation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Behne, Patrick Alan
The modeling of the detectability of special nuclear material (SNM) at ports and border crossings requires accurate knowledge of the background radiation at those locations. Background radiation originates from two main sources, cosmic and terrestrial. Cosmic background is produced by high-energy galactic cosmic rays (GCR) entering the atmosphere and inducing a cascade of particles that eventually impact the earth’s surface. The solar modulation potential represents one of the primary inputs to modeling cosmic background radiation. Usosokin et al. formally define solar modulation potential as “the mean energy loss [per unit charge] of a cosmic ray particle inside the heliosphere…” Modulationmore » potential, a function of elevation, location, and time, shares an inverse relationship with cosmic background radiation. As a result, radiation detector thresholds require adjustment to account for differing background levels, caused partly by differing solar modulations. Failure to do so can result in higher rates of false positives and failed detection of SNM for low and high levels of solar modulation potential, respectively. This study focuses on solar modulation’s time dependence, and seeks the best method to predict modulation for future dates using Python. To address the task of predicting future solar modulation, we utilize both non-linear least squares sinusoidal curve fitting and cubic spline interpolation. This material will be published in transactions of the ANS winter meeting of November, 2016.« less
Massive stars: privileged sources of cosmic-rays for interstellar astrochemistry
NASA Astrophysics Data System (ADS)
De Becker, M.
2015-01-01
Massive stars can be considered as crucial engines for interstellar physics. They are indeed the main providers of UV radiation field, and constitute a substantial source of chemical enrichment. On their evolution time-scale (at most about 10 Myr), they typically stay close to their formation site, i.e. close to molecular clouds very rich in interstellar molecules. These stellar objects have also the property to be involved in particle acceleration processes leading to the production of high energy charged particles (cosmic-rays). After rejection in the interstellar medium, these particles will play a substantial role in processes such as those simulated in various facilities dedicated to experimental astrochemistry. This short contribution intends to put these particles, crucial for astrochemistry, in their adequate astrophysical context.
NASA Technical Reports Server (NTRS)
Ellison, D. C.; Jones, F. C.; Eichler, D.
1983-01-01
Both hydrodynamic calculations (Drury and Volk, 1981, and Axford et al., 1982) and kinetic simulations imply the existence of thermal subshocks in high-Mach-number cosmic-ray-mediated shocks. The injection efficiency of particles from the thermal background into the diffusive shock-acceleration process is determined in part by the sharpness and compression ratio of these subshocks. Results are reported for a Monte Carlo simulation that includes both the back reaction of accelerated particles on the inflowing plasma, producing a smoothing of the shock transition, and the free escape of particles allowing arbitrarily large overall compression ratios in high-Mach-number steady-state shocks. Energy spectra and estimates of the proportion of thermal ions accelerated to high energy are obtained.
NASA Astrophysics Data System (ADS)
Ellison, D. C.; Jones, F. C.; Eichler, D.
1983-08-01
Both hydrodynamic calculations (Drury and Volk, 1981, and Axford et al., 1982) and kinetic simulations imply the existence of thermal subshocks in high-Mach-number cosmic-ray-mediated shocks. The injection efficiency of particles from the thermal background into the diffusive shock-acceleration process is determined in part by the sharpness and compression ratio of these subshocks. Results are reported for a Monte Carlo simulation that includes both the back reaction of accelerated particles on the inflowing plasma, producing a smoothing of the shock transition, and the free escape of particles allowing arbitrarily large overall compression ratios in high-Mach-number steady-state shocks. Energy spectra and estimates of the proportion of thermal ions accelerated to high energy are obtained.
Visual phenomena induced by cosmic rays and accelerated particles
NASA Technical Reports Server (NTRS)
Tobias, C. A.; Budinger, T. F.; Leith, J. T.; Mamoon, A.; Chapman, P. K.
1972-01-01
Experiments, conducted at cyclotrons together with observations by Apollo astronauts, suggest with little doubt that cosmic nuclei interacting with the visual apparatus cause the phenomenon of light flashes seen on translunar and transearth coast over the past four Apollo missions. Other experiments with high and low energy neutrons and a helium ion beam suggest that slow protons and helium ions with a stopping power greater than 10 to the 8th power eV/gram sq cm can cause the phenomenon in the dark adapted eye. It was demonstrated that charged particles induced by neutrons and helium ions can stimulate the visual apparatus. Some approaches to understanding the long term mission effects of galactic cosmic nuclei interacting with man and his nervous system are outlined.
The spectrum of high-energy cosmic rays measured with KASCADE-Grande
NASA Astrophysics Data System (ADS)
Apel, W. D.; Arteaga-Velázquez, J. C.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Buchholz, P.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Finger, M.; Fuhrmann, D.; Ghia, P. L.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huber, D.; Huege, T.; Kampert, K.-H.; Kang, D.; Kickelbick, D.; Klages, H. O.; Link, K.; Łuczak, P.; Ludwig, M.; Mathes, H. J.; Mayer, H. J.; Melissas, M.; Milke, J.; Mitrica, B.; Morello, C.; Navarra, G.; Oehlschläger, J.; Ostapchenko, S.; Over, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.
2012-08-01
The energy spectrum of cosmic rays between 1016 eV and 1018 eV, derived from measurements of the shower size (total number of charged particles) and the total muon number of extensive air showers by the KASCADE-Grande experiment, is described. The resulting all-particle energy spectrum exhibits strong hints for a hardening of the spectrum at approximately 2 · 1016 eV and a significant steepening at ≈8 · 1016 eV. These observations challenge the view that the spectrum is a single power law between knee and ankle. Possible scenarios generating such features are discussed in terms of astrophysical processes that may explain the transition region from galactic to extragalactic origin of cosmic rays.
The CosmicWatch Desktop Muon Detector: a self-contained, pocket sized particle detector
NASA Astrophysics Data System (ADS)
Axani, S. N.; Frankiewicz, K.; Conrad, J. M.
2018-03-01
The CosmicWatch Desktop Muon Detector is a self-contained, hand-held cosmic ray muon detector that is valuable for astro/particle physics research applications and outreach. The material cost of each detector is under 100 and it takes a novice student approximately four hours to build their first detector. The detectors are powered via a USB connection and the data can either be recorded directly to a computer or to a microSD card. Arduino- and Python-based software is provided to operate the detector and an online application to plot the data in real-time. In this paper, we describe the various design features, evaluate the performance, and illustrate the detectors capabilities by providing several example measurements.
NASA Technical Reports Server (NTRS)
Wu, S. T.
2000-01-01
The cosmic ray division participation in the cooperative agreement was activated in the second year. The scientific goals will be analysis of cosmic ray data from the Japanese-American Cooperative Emulsion Experiments (JACEE). Measurements of primary cosmic rays in the JACEE emulsion chambers will be made to derive for each detected particle the deposited energy in the chamber and the primary charge (atomic number). The data will be corrected to the primary flux above the atmosphere, and the composition and energy spectra will be derived. The spectra of the individual elements will be interpreted in context with the supernova shock and other models of cosmic ray acceleration. Additional information is contained in the original extended abstract.
Dietary modulation of the effects of exposure to 56Fe particles
NASA Astrophysics Data System (ADS)
Rabin, B. M.; Joseph, J. A.; Shukitt-Hale, B.; Carey, A. N.
On exploratory missions to other planets, astronauts will be exposed to galactic cosmic rays composed of protons and heavy particles, such as 56Fe. Long-term exposure to these particles can cause cancer. However, there are significant uncertainties in the risk estimates for the probability of developing heavy particle-induced cancer, and in the amount of shielding needed to provide an adequate level of radiation protection. The results of this preliminary study, using a ground-based model for exposure to cosmic rays, show reduced tumorigenesis in rats maintained on diets containing blueberry or strawberry extract prior to exposure to 56Fe particles. Because the study was not initially designed to evaluate tumorigenesis following exposure to 56Fe particles, additional research is needed to evaluate the effectiveness of strawberry and blueberry supplementation. However, the preliminary results presented in this study suggest that diets containing antioxidant phytochemicals can provide additional radiation protection on interplanetary voyages.
Multiply charged particles of the primary cosmic rays with energies greater than about 2 TeV
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ivanenko, I.P.; Grigorov, N.L.; Shestoperov, V.IA.
1986-08-01
Data on the energy spectra and charge composition of primary cosmic ray particles with energies greater than about 2 TeV are analyzed. The equipment on the Kosmos 1543 satellite used to obtain the data is described. Protons and alpha particles are detected, and the nuclei are separated into H, M, VH, and alpha groups. It is determined that the charge compositions of the primary nuclei with z greater than about 2 at energies greater than about 2 TeV compare well with data obtained at energies greater than about 1-10 GeV/nucleon. 8 references.
Research in particles and fields
NASA Technical Reports Server (NTRS)
Stone, E. C.; Davis, L., Jr.; Mewaldt, R. A.; Prince, T. A.
1987-01-01
Discussed are the research activities in Cosmic Rays, Gamma Rays, and Astrophysical Plasmas supported under NASA Grant NGR 05-002-160. The report is divided into sections which describe the activities, followed by a bibliography. This research program is directed toward the investigation of the astrophysical aspects of cosmic rays and gamma rays and of the radiation and electromagnetic field environment of the Earth and other planets. These investigations are carried out by means of energetic particle and photon detector systems flown on spacecraft and balloons.
Back-tracking of primary particle trajectories for muons detected at the Earth surface
NASA Astrophysics Data System (ADS)
Shutenko, V. V.
2017-01-01
Investigations of cosmic rays on the surface of the Earth allow to derive information of applied character on the conditions of the interplanetary magnetic field and of the geomagnetic field. For this purpose, it is necessary to collate trajectories of particles detected in the ground-based detector to trajectories of primary cosmic rays in the heliosphere. This problem is solved by means of various back-tracking methods. In this work, one of such methods is presented.
Cosmic censorship and Weak Gravity Conjecture in the Einstein-Maxwell-dilaton theory
NASA Astrophysics Data System (ADS)
Yu, Ten-Yeh; Wen, Wen-Yu
2018-06-01
We explore the cosmic censorship in the Einstein-Maxwell-dilaton theory following Wald's thought experiment to destroy a black hole by throwing in a test particle. We discover that at probe limit the extremal charged dilaton black hole could be destroyed by a test particle with specific energy. Nevertheless the censorship is well protected if backreaction or self-force is included. At the end, we discuss an interesting connection between Hoop Conjecture and Weak Gravity Conjecture.
Research in particles and fields
NASA Technical Reports Server (NTRS)
Stone, E. C.; Davis, L., Jr.; Mewaldt, R. A.; Prince, T. A.
1985-01-01
Research activities in Cosmic Rays, Gamma Rays, and Astrophysical Plasmas supported under NASA Grant NGR 05-002-160 are discussed. The report is divided into sections which describe the activities, followed by a bibliography. This group's research program is directed toward the investigation of the astrophysical aspects of cosmic rays and gamma rays and of the radiation and electromagnetic field environment of the Earth and other planets. These investigations are carried out by means of energetic particle and photon detector systems flown on spacecraft and balloons.
Search for 1/3e and 2/3e charged quarks in the cosmic radiation at 2750-m altitude.
NASA Technical Reports Server (NTRS)
Cox, A. J.; Beauchamp, W. T.; Bowen, T.; Kalbach, R. M.
1972-01-01
A scintillation counter telescope consisting of eight liquid scintillation counters and four wide-gap spark chambers was used to search for particles with electric charge 1/3e and 2/3e in cosmic rays at 2750 m above sea level. No such particles were detected during the 1500-hr experimental run. Upper limits on the vertical fluxes are established, and estimates of the corresponding sea-level fluxes are made for comparison with previous results.
Observed antiprotons and energy dependent confinement of cosmic rays: A conflict?
NASA Technical Reports Server (NTRS)
Stephens, S. A.
1985-01-01
In the frame work of energy dependent confinement for cosmic rays, the energy spectrum inside the source is flatter than that observed. Antiproton observation suggests large amount of matter is being traversed by cosmic rays in some sources. As a result, secondary particles are produced in abundance. Their spectra was calculated and it is shown that the energy dependent confinement model is in conflict with some observations.
Exact solutions for sporadic acceleration of cosmic rays
NASA Technical Reports Server (NTRS)
Cowsik, R.
1985-01-01
The steady state spectra of cosmic rays which are subject to a sporadic acceleration process, wherein the gain in energy in each encounter is a finite fraction of the particle energy are discussed. They are derived from a mathematical model which includes the possibility of energy dependent leakage of cosmic rays from the galaxy. Comparison with observations allows limits to be placed on the frequency and efficiency of such encounters.
Plasmoid Impacts on Neutron Stars and Highest Energy Cosmic Rays
DOE Office of Scientific and Technical Information (OSTI.GOV)
Litwin, C.; Rosner, R.
Particle acceleration by electrostatic polarization fields that arise in plasmas streaming across magnetic fields is discussed as a possible acceleration mechanism of highest energy ({approx}>10{sup 20} eV) cosmic rays. Specifically, plasmoids arising in planetoid impacts onto neutron star magnetospheres are considered. We find that such impacts at plausible rates may account for the observed flux and energy spectrum of the highest energy cosmic rays.
NASA Technical Reports Server (NTRS)
Zolensky, M. E.; Mackinnon, I. D. R.; Mckay, D. S.
1984-01-01
As the Earth travels about the Sun it continuously sweeps up material laying in its path. The material includes dust-sized fragments of the meteors, comets and asteroids that have passed by as well as much older particles from out between the stars. These grains first become caught in the mesosphere and then slowly pass down through the stratosphere and the troposphere, finally raining down upon the Earth's surface. In the stratosphere the cosmic dust particles encounter increasing amounts of contaminants from the Earth. At the highest reaches of Earth's atmosphere these contaminants consists mainly of dust from the most explosive volcanoes, rocket exhaust, and other manmade space debris. In the troposphere windborne particles and pollen become an increasingly larger fraction of the atmospheric dust load. An increased knowledge of the nature of cosmic particles is suggested.
NASA Astrophysics Data System (ADS)
Leitgab, M.
2018-02-01
A charged particle measurement experiment mounted externally to the Deep Space Gateway is proposed, contributing to improving astronaut radiation exposure management during Solar Particle Events and Extra Vehicular Activities.
Acceleration of petaelectronvolt protons in the Galactic Centre
NASA Astrophysics Data System (ADS)
HESS Collaboration; Abramowski, A.; Aharonian, F.; Benkhali, F. Ait; Akhperjanian, A. G.; Angüner, E. O.; Backes, M.; Balzer, A.; Becherini, Y.; Tjus, J. Becker; Berge, D.; Bernhard, S.; Bernlöhr, K.; Birsin, E.; Blackwell, R.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Bregeon, J.; Brun, F.; Brun, P.; Bryan, M.; Bulik, T.; Carr, J.; Casanova, S.; Chakraborty, N.; Chalme-Calvet, R.; Chaves, R. C. G.; Chen, A.; Chrétien, M.; Colafrancesco, S.; Cologna, G.; Conrad, J.; Couturier, C.; Cui, Y.; Davids, I. D.; Degrange, B.; Deil, C.; Dewilt, P.; Djannati-Ataï, A.; Domainko, W.; Donath, A.; Drury, L. O'C.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, K.; Eger, P.; Ernenwein, J.-P.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gabici, S.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Gottschall, D.; Goyal, A.; Grondin, M.-H.; Grudzińska, M.; Hadasch, D.; Häffner, S.; Hahn, J.; Hawkes, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hofverberg, P.; Hoischen, C.; Holler, M.; Horns, D.; Ivascenko, A.; Jacholkowska, A.; Jamrozy, M.; Janiak, M.; Jankowsky, F.; Jung-Richardt, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kerszberg, D.; Khélifi, B.; Kieffer, M.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Krayzel, F.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lau, J.; Lefaucheur, J.; Lefranc, V.; Lemiére, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Lui, R.; Marandon, V.; Marcowith, A.; Mariaud, C.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; Meintjes, P. J.; Menzler, U.; Meyer, M.; Mitchell, A. M. W.; Moderski, R.; Mohamed, M.; Morå, K.; Moulin, E.; Murach, T.; de Naurois, M.; Niemiec, J.; Oakes, L.; Odaka, H.; Öttl, S.; Ohm, S.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Arribas, M. Paz; Pekeur, N. W.; Pelletier, G.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Poon, H.; Prokoph, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Reichardt, I.; Reimer, A.; Reimer, O.; Renaud, M.; de Los Reyes, R.; Rieger, F.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Salek, D.; Sanchez, D. A.; Santangelo, A.; Sasaki, M.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwemmer, S.; Seyffert, A. S.; Simoni, R.; Sol, H.; Spanier, F.; Spengler, G.; Spies, F.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tluczykont, M.; Trichard, C.; Tuffs, R.; Valerius, K.; van der Walt, J.; van Eldik, C.; van Soelen, B.; Vasileiadis, G.; Veh, J.; Venter, C.; Viana, A.; Vincent, P.; Vink, J.; Voisin, F.; Völk, H. J.; Vuillaume, T.; Wagner, S. J.; Wagner, P.; Wagner, R. M.; Weidinger, M.; Weitzel, Q.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Yang, R.; Zabalza, V.; Zaborov, D.; Zacharias, M.; Zdziarski, A. A.; Zech, A.; Zefi, F.; Żywucka, N.
2016-03-01
Galactic cosmic rays reach energies of at least a few petaelectronvolts (of the order of 1015 electronvolts). This implies that our Galaxy contains petaelectronvolt accelerators (‘PeVatrons’), but all proposed models of Galactic cosmic-ray accelerators encounter difficulties at exactly these energies. Dozens of Galactic accelerators capable of accelerating particles to energies of tens of teraelectronvolts (of the order of 1013 electronvolts) were inferred from recent γ-ray observations. However, none of the currently known accelerators—not even the handful of shell-type supernova remnants commonly believed to supply most Galactic cosmic rays—has shown the characteristic tracers of petaelectronvolt particles, namely, power-law spectra of γ-rays extending without a cut-off or a spectral break to tens of teraelectronvolts. Here we report deep γ-ray observations with arcminute angular resolution of the region surrounding the Galactic Centre, which show the expected tracer of the presence of petaelectronvolt protons within the central 10 parsecs of the Galaxy. We propose that the supermassive black hole Sagittarius A* is linked to this PeVatron. Sagittarius A* went through active phases in the past, as demonstrated by X-ray outburstsand an outflow from the Galactic Centre. Although its current rate of particle acceleration is not sufficient to provide a substantial contribution to Galactic cosmic rays, Sagittarius A* could have plausibly been more active over the last 106-107 years, and therefore should be considered as a viable alternative to supernova remnants as a source of petaelectronvolt Galactic cosmic rays.
NASA Astrophysics Data System (ADS)
Nar, Sevda Yeliz; Cakir, Altan
2018-02-01
Particles produced by nuclear decay, cosmic radiation and reactions can be identified through various methods. One of these methods that has been effective in the last century is the cloud chamber. The chamber makes visible cosmic particles that we are exposed to radiation per second. Diffusion cloud chamber is a kind of cloud chamber that is cooled by dry ice. This traditional model has some application difficulties. In this work, Peltier-based cloud chamber cooled by thermoelectric modules is studied. The new model provided uniformly cooled base of the chamber, moreover, it has longer lifetime than the traditional chamber in terms of observation time. This gain has reduced the costs which spent each time for cosmic particle observation. The chamber is an easy-to-use system according to traditional diffusion cloud chamber. The new model is portable, easier to make, and can be used in the nuclear physics experiments. In addition, it would be very useful to observe Muons which are the direct evidence for Lorentz contraction and time expansion predicted by Einsteins special relativity principle.
AMS-02 positron excess and indirect detection of three-body decaying dark matter
NASA Astrophysics Data System (ADS)
Cheng, Hsin-Chia; Huang, Wei-Chih; Huang, Xiaoyuan; Low, Ian; Sming Tsai, Yue-Lin; Yuan, Qiang
2017-03-01
We consider indirect detection of meta-stable dark matter particles decaying into a stable neutral particle and a pair of standard model fermions. Due to the softer energy spectra from the three-body decay, such models could potentially explain the AMS-02 positron excess without being constrained by the Fermi-LAT gamma-ray data and the cosmic ray anti-proton measurements. We scrutinize over different final state fermions, paying special attention to handling of the cosmic ray background and including various contributions from cosmic ray propagation with the help of the LIKEDM package. It is found that primary decays into an electron-positron pair and a stable neutral particle could give rise to the AMS-02 positron excess and, at the same time, stay unscathed against the gamma-ray and anti-proton constraints. Decays to a muon pair or a mixed flavor electron-muon pair may also be viable depending on the propagation models. Decays to all other standard model fermions are severely disfavored.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cheng, Hsin-Chia; Huang, Wei-Chih; Huang, Xiaoyuan
We consider indirect detection of meta-stable dark matter particles decaying into a stable neutral particle and a pair of standard model fermions. Due to the softer energy spectra from the three-body decay, such models could potentially explain the AMS-02 positron excess without being constrained by the Fermi-LAT gamma-ray data and the cosmic ray anti-proton measurements. We scrutinize over different final state fermions, paying special attention to handling of the cosmic ray background and including various contributions from cosmic ray propagation with the help of the LIKEDM package. It is found that primary decays into an electron-positron pair and a stablemore » neutral particle could give rise to the AMS-02 positron excess and, at the same time, stay unscathed against the gamma-ray and anti-proton constraints. Decays to a muon pair or a mixed flavor electron-muon pair may also be viable depending on the propagation models. Decays to all other standard model fermions are severely disfavored.« less
KASCADE-Grande observation of features in the cosmic ray spectrum between knee and ankle
NASA Astrophysics Data System (ADS)
Haungs, A.; Apel, W. D.; Arteaga-Velazquez, J. C.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Finger, M.; Fuchs, B.; Fuhrmann, D.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Heck, D.; Hörandel, J. R.; Huber, D.; Huege, T.; Kampert, K.-H.; Kang, D.; Klages, H. O.; Link, K.; Łuczak, P.; Ludwig, M.; Mathes, H. J.; Mayer, H. J.; Melissas, M.; Milke, J.; Morello, C.; Oehlschläger, J.; Ostapchenko, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schoo, S.; Schroder, F.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.
2013-02-01
The detection of high-energy cosmic rays above a few hundred TeV is realized by the observation of extensive air-showers. By using the multi-detector setup of KASCADE-Grande, and here in particular the detectors of the large Grande array, the energy spectrum and the elemental composition of high-energy cosmic rays in the energy range from 10 PeV to 1 EeV are investigated. The estimation of energy and mass of the high-energy primary particles is based on the combined analysis of the total number of charged particles and the total number of muons measured by the detector arrays of Grande and KASCADE, respectively. The latest analysis results have shown that in the all-particle spectrum two features are present: a hardening of the spectrum at energies around 20 PeV and a steepening, i.e. a knee-like structure, at 80-90 PeV. The latter one was found to be due to a decrease of flux of the heavy mass component.
NASA Astrophysics Data System (ADS)
Hoffman, Jascha
2011-05-01
Charles Jencks designs landscapes and sculptures to convey concepts in astronomy, biology and mathematics -- notably at CERN, Europe's particle-physics lab near Geneva, Switzerland, and in his Garden of Cosmic Speculation near Dumfries in Scotland, UK. On the launch of his new book, he discusses green architecture and metaphor.
THE FLOW AROUND A COSMIC STRING. I. HYDRODYNAMIC SOLUTION
DOE Office of Scientific and Technical Information (OSTI.GOV)
Beresnyak, Andrey; Nordita, KTH Royal Institute of Technology and Stockholm University, SE-10691
2015-05-10
Cosmic strings are linear topological defects which are hypothesized to be produced during inflation. Most searches for strings have relied on the string’s lensing of background galaxies or the cosmic microwave background. In this paper, I obtained a solution for the supersonic flow of collisional gas past the cosmic string which has two planar shocks with a shock compression ratio that depends on the angle defect of the string and its speed. The shocks result in the compression and heating of the gas and, given favorable conditions, particle acceleration. Gas heating and over-density in an unusual wedge shape can bemore » detected by observing the Hi line at high redshifts. Particle acceleration can occur in the present-day universe when the string crosses the hot gas contained in galaxy clusters and, since the consequences of such a collision persist for cosmological timescales, could be located by looking at unusual large-scale radio sources situated on a single spatial plane.« less
Cosmic Radiation Detection and Observations
NASA Astrophysics Data System (ADS)
Ramirez Chavez, Juan; Troncoso, Maria
Cosmic rays consist of high-energy particles accelerated from remote supernova remnant explosions and travel vast distances throughout the universe. Upon arriving at earth, the majority of these particles ionize gases in the upper atmosphere, while others interact with gas molecules in the troposphere and producing secondary cosmic rays, which are the main focus of this research. To observe these secondary cosmic rays, a detector telescope was designed and equipped with two silicon photomultipliers (SiPMs). Each SiPM is coupled to a bundle of 4 wavelength shifting optical fibers that are embedded inside a plastic scintillator sheet. The SiPM signals were amplified using a fast preamplifier with coincidence between detectors established using a binary logic gate. The coincidence events were recorded with two devices; a digital counter and an Arduino micro-controller. For detailed analysis of the SiPM waveforms, a DRS4 sensory digitizer captured the waveforms for offline analysis with the CERN software package Physics Analysis Workstation in a Linux environment. Results from our experiments would be presented. Hartnell College STEM Internship Program.
Lagrangian methods of cosmic web classification
NASA Astrophysics Data System (ADS)
Fisher, J. D.; Faltenbacher, A.; Johnson, M. S. T.
2016-05-01
The cosmic web defines the large-scale distribution of matter we see in the Universe today. Classifying the cosmic web into voids, sheets, filaments and nodes allows one to explore structure formation and the role environmental factors have on halo and galaxy properties. While existing studies of cosmic web classification concentrate on grid-based methods, this work explores a Lagrangian approach where the V-web algorithm proposed by Hoffman et al. is implemented with techniques borrowed from smoothed particle hydrodynamics. The Lagrangian approach allows one to classify individual objects (e.g. particles or haloes) based on properties of their nearest neighbours in an adaptive manner. It can be applied directly to a halo sample which dramatically reduces computational cost and potentially allows an application of this classification scheme to observed galaxy samples. Finally, the Lagrangian nature admits a straightforward inclusion of the Hubble flow negating the necessity of a visually defined threshold value which is commonly employed by grid-based classification methods.
Cosmic ray propagation and containment
NASA Technical Reports Server (NTRS)
Parker, E. N.
1976-01-01
The cosmic rays, an active gaseous component of the disk of the galaxy, are considered along with their propagation and containment as a part of the general dynamics of the disk. The sources of cosmic rays are a matter of speculation. The disk is inflated by the cosmic ray gas pressure comparable to the magnetic pressure, but the rate of inflation is unknown. The time spent by the individual cosmic ray particles in the disk is inversely proportional to the cosmic ray production rate. It is evident from the decay of Be(1c) that the cosmic rays circulate through a volume of space perhaps ten times the thickness of the gaseous disk, suggesting a magnetic halo extending out approximately 1 kpc from either face of the disk. The cosmic rays may be responsible for the halo by inflating the magnetic fields of the disk. Extension of the fields to 1 kpc would imply a high production rate and short life of cosmic rays in the dense gaseous disk of the galaxy.
Particle Physics at the Cosmic, Intensity, and Energy Frontiers
DOE Office of Scientific and Technical Information (OSTI.GOV)
Essig, Rouven
Major efforts at the Intensity, Cosmic, and Energy frontiers of particle physics are rapidly furthering our understanding of the fundamental constituents of Nature and their interactions. The overall objectives of this research project are (1) to interpret and develop the theoretical implications of the data collected at these frontiers and (2) to provide the theoretical motivation, basis, and ideas for new experiments and for new analyses of experimental data. Within the Intensity Frontier, an experimental search for a new force mediated by a GeV-scale gauge boson will be carried out with the $A'$ Experiment (APEX) and the Heavy Photon Searchmore » (HPS), both at Jefferson Laboratory. Within the Cosmic Frontier, contributions are planned to the search for dark matter particles with the Fermi Gamma-ray Space Telescope and other instruments. A detailed exploration will also be performed of new direct detection strategies for dark matter particles with sub-GeV masses to facilitate the development of new experiments. In addition, the theoretical implications of existing and future dark matter-related anomalies will be examined. Within the Energy Frontier, the implications of the data from the Large Hadron Collider will be investigated. Novel search strategies will be developed to aid the search for new phenomena not described by the Standard Model of particle physics. By combining insights from all three particle physics frontiers, this research aims to increase our understanding of fundamental particle physics.« less
NIU, Kiyoshi
2008-01-01
This is a historical review of the discovery of naked charm particles and lifetime differences among charm species. These discoveries in the field of cosmic-ray physics were made by the innovation of nuclear emulsion techniques in Japan. A pair of naked charm particles was discovered in 1971 in a cosmic-ray interaction, three years prior to the discovery of the hidden charm particle, J/Ψ, in western countries. Lifetime differences between charged and neutral charm particles were pointed out in 1975, which were later re-confirmed by the collaborative Experiment E531 at Fermilab. Japanese physicists led by K.Niu made essential contributions to it with improved emulsion techniques, complemented by electronic detectors. This review also discusses the discovery of artificially produced naked charm particles by us in an accelerator experiment at Fermilab in 1975 and of multiple-pair productions of charm particles in a single interaction in 1987 by the collaborative Experiment WA75 at CERN. PMID:18941283
NASA Technical Reports Server (NTRS)
Flynn, G. J.; Sutton, S. R.
1992-01-01
Major-element abundances in 11 C, C?, and TCA cosmic dust particles have been measured using SEM and TEM energy dispersive X-ray (EDX) systems. The Fe/Ni ratio, when coupled with major element abundances, appears to be a useful discriminator of cosmic particles. Three particles classified as C?, but having Fe/Ni peak height ratios similar to those measured on the powdered Allende meteorite sample in their HSC EDX spectra, exhibit chondritic minor-/trace-element abundance patterns, suggesting they are extraterrestrial. The one particle classified as C-type, but without detectable Ni in its JSC EDX spectrum, exhibits an apparently nonchondritic minor-/trace-element abundance pattern. A class of particles that are chondritic except for large depletions in the volatile elements Zn and S has been identified. It is likely that these particles condensed with a C1 abundance pattern and that Zn and S were removed by some subsequent process.
Small Particles Intact Capture Experiment (SPICE)
NASA Technical Reports Server (NTRS)
Nishioka, Ken-Ji; Carle, G. C.; Bunch, T. E.; Mendez, David J.; Ryder, J. T.
1994-01-01
The Small Particles Intact Capture Experiment (SPICE) will develop technologies and engineering techniques necessary to capture nearly intact, uncontaminated cosmic and interplanetary dust particles (IDP's). Successful capture of such particles will benefit the exobiology and planetary science communities by providing particulate samples that may have survived unaltered since the formation of the solar system. Characterization of these particles may contribute fundamental data to our knowledge of how these particles could have formed into our planet Earth and, perhaps, contributed to the beginnings of life. The term 'uncontaminated' means that captured cosmic and IDP particles are free of organic contamination from the capture process and the term 'nearly intact capture' means that their chemical and elemental components are not materially altered during capture. The key to capturing cosmic and IDP particles that are organic-contamination free and nearly intact is the capture medium. Initial screening of capture media included organic foams, multiple thin foil layers, and aerogel (a silica gel); but, with the exception of aerogel, the requirements of no contamination or nearly intact capture were not met. To ensure no contamination of particles in the capture process, high-purity aerogel was chosen. High-purity aerogel results in high clarity (visual clearness), a useful quality in detection and recovery of embedded captured particles from the aerogel. P. Tsou at the Jet Propulsion Laboratory (JPL) originally described the use of aerogel for this purpose and reported laboratory test results. He has flown aerogel as a 'GAS-can Lid' payload on STS-47 and is evaluating the results. The Timeband Capture Cell Experiment (TICCE), a Eureca 1 experiment, is also flying aerogel and is scheduled for recovery in late April.
2010-02-01
Fluxes at Aragats-Space Environmental Center (ASEC) Ashot A. Chilingarian Alikhanyan Physics Institute Cosmic Ray Division 2 Alikhanian...GMS occurred during 23rd Solar activity cycle demonstrate that Cosmic Ray increase during GMS occurs coherently (or ~ 1 hour in advance) with abrupt...data on Solar bursts and secondary cosmic ray data. The magnetometer operates stable, noise level is low. 15. SUBJECT TERMS
1992-07-15
cosmic - ray transport. NASA TM X-2440, 1972:117-122. DoD Space Radiation Concerns 8 2. Atkins SG, Small JT, McFarland TH. Military Man-in Space (MMIS...136. 29. Silberberg R, Tsao CH, Adams JH Jr., Letaw JR. Radiation doses and LET distributions of cosmic rays . Rad. Res., 1984, 98:209-226. 30. Stauber...levels on mission success and completion. Natural Radiation Trapped Radiation Belts Galactic Cosmic Rays (GCR) Solar Particle Events (SPEs) Man-Made
High Energy Astronomy Observatory (HEAO)
1970-01-01
This schematic details the third High Energy Astronomy Observatory (HEAO)-3. The HEAO-3's mission was to survey and map the celestial sphere for gamma-ray flux and make detailed measurements of cosmic-ray particles. It carried three scientific experiments: a gamma-ray spectrometer, a cosmic-ray isotope experiment, and a heavy cosmic-ray nuclei experiment. The HEAO-3 was originally identified as HEAO-C but the designation was changed once the spacecraft achieved orbit.
Single Event Effects: Space and Atmospheric Environments
NASA Technical Reports Server (NTRS)
Barth, Janet L.
2003-01-01
The paper discusses the following: 1. Sun-Earth connections. 2. Heavy ions: galactic cosmic rays; solar particle events. 3. Protons: solar particle events; trapped. 4. Atmospheric neutrons. 5. Summary.
Massless charged particles: Cosmic censorship, and the third law of black hole mechanics
NASA Astrophysics Data System (ADS)
Fairoos, C.; Ghosh, Avirup; Sarkar, Sudipta
2017-10-01
The formulation of the laws of Black hole mechanics assumes the stability of black holes under perturbations in accordance with the "cosmic censorship hypothesis" (CCH). CCH prohibits the formation of a naked singularity by a physical process from a regular black hole solution with an event horizon. Earlier studies show that naked singularities can indeed be formed leading to the violation of CCH if a near-extremal black hole is injected with massive charged particles and the backreaction effects are neglected. We investigate the validity of CCH by considering the infall of charged massless particles as well as a charged null shell. We also discuss the issue of the third law of Black hole mechanics in the presence of null charged particles by considering various possibilities.
An algorithm to resolve γ-rays from charged cosmic rays with DAMPE
NASA Astrophysics Data System (ADS)
Xu, Zun-Lei; Duan, Kai-Kai; Shen, Zhao-Qiang; Lei, Shi-Jun; Dong, Tie-Kuang; Gargano, Fabio; Garrappa, Simone; Guo, Dong-Ya; Jiang, Wei; Li, Xiang; Liang, Yun-Feng; Mazziotta, Mario Nicola; Munoz Salinas, Maria Fernanda; Su, Meng; Vagelli, Valerio; Yuan, Qiang; Yue, Chuan; Zang, Jing-Jing; Zhang, Ya-Peng; Zhang, Yun-Long; Zimmer, Stephan
2018-03-01
The DArk Matter Particle Explorer (DAMPE), also known as Wukong in China, which was launched on 2015 December 17, is a new high energy cosmic ray and γ-ray satellite-borne observatory. One of the main scientific goals of DAMPE is to observe GeV-TeV high energy γ-rays with accurate energy, angular and time resolution, to indirectly search for dark matter particles and for the study of high energy astrophysics. Due to the comparatively higher fluxes of charged cosmic rays with respect to γ-rays, it is challenging to identify γ-rays with sufficiently high efficiency, minimizing the amount of charged cosmic ray contamination. In this work we present a method to identify γ-rays in DAMPE data based on Monte Carlo simulations, using the powerful electromagnetic/hadronic shower discrimination provided by the calorimeter and the veto detection of charged particles provided by the plastic scintillation detector. Monte Carlo simulations show that after this selection the number of electrons and protons that contaminate the selected γ-ray events at ∼ 10GeV amounts to less than 1% of the selected sample. Finally, we use flight data to verify the effectiveness of the method by highlighting known γ-ray sources in the sky and by reconstructing preliminary light curves of the Geminga pulsar.
Cosmic Ray Physics with the KASCADE-Grande Observatory
NASA Astrophysics Data System (ADS)
Arteaga-Velázquez, J. C.; Apel, W. D.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Fuhrmann, D.; Gherghel-Lascu, A.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huege, T.; Kampert, K.-H.; Kang, D.; Klages, H. O.; Link, K.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Oehlschläger, J.; Ostapchenko, S.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schoo, S.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Zabierowski, J.
The existence of a knee at a few PeV in the all-particle cosmic ray energy spectrum has been well established by several experiments but its physical origin has eluded researches for a long time. It is believed that keys to disentangle the mystery could be found in the spectrum and the composition of cosmic rays between 1 PeV and 1 EeV. A first detailed look into the elemental chemical abundances of cosmic rays in this energy regime was provided by both the KASCADE and the KASCADE-Grande experiments. Their measurements opened the door to a wealth of new data on the subject, which led to the discovery of new structures in the all-particle energy spectrum and the confirmation of knee-like features in the spectra of individual mass groups, as well as the observation of an unexpected ankle-like structure at around 100 PeV in the flux of the light component of cosmic rays. In this contribution, early findings with the KASCADE-Grande experiment will be reviewed and then a short update on the analyses currently performed with the data of the observatory will be presented.
Predicting space climate change
NASA Astrophysics Data System (ADS)
Balcerak, Ernie
2011-10-01
Galactic cosmic rays and solar energetic particles can be hazardous to humans in space, damage spacecraft and satellites, pose threats to aircraft electronics, and expose aircrew and passengers to radiation. A new study shows that these threats are likely to increase in coming years as the Sun approaches the end of the period of high solar activity known as “grand solar maximum,” which has persisted through the past several decades. High solar activity can help protect the Earth by repelling incoming galactic cosmic rays. Understanding the past record can help scientists predict future conditions. Barnard et al. analyzed a 9300-year record of galactic cosmic ray and solar activity based on cosmogenic isotopes in ice cores as well as on neutron monitor data. They used this to predict future variations in galactic cosmic ray flux, near-Earth interplanetary magnetic field, sunspot number, and probability of large solar energetic particle events. The researchers found that the risk of space weather radiation events will likely increase noticeably over the next century compared with recent decades and that lower solar activity will lead to increased galactic cosmic ray levels. (Geophysical Research Letters, doi:10.1029/2011GL048489, 2011)
A Shifting Shield Provides Protection Against Cosmic Rays
NASA Astrophysics Data System (ADS)
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 at Earth.In a new study, a team of scientists led by Nicola Tomassetti (University of Perugia, Italy) has modeled this solar modulation to better understand the process by which the Suns changing activity influences the cosmic ray flux that reaches us at Earth.Modeling a LagTomassetti and collaborators model uses two solar-activity observables as inputs: the number of sunspots and the tilt angle of the heliospheric current sheet. By modeling basic transport processes in the heliosphere, the authors then track the impact that the changing solar properties have on incoming galactic cosmic rays. In particular, the team explores the time lag between when solar activity changes and when we see the responding change in the cosmic-ray flux.Cosmic-ray flux observations are best fit by the authors model when an 8-month lag is included (red bold line). A comparison model with no lag (black dashed line) is included. [Tomassetti et al. 2017]By comparing their model outputs to the large collection of time-dependent observations of cosmic-ray fluxes, Tomassetti and collaborators show that the best fit to data occurs with an 8-month lag between changing solar activity and local cosmic-ray flux modulation.This is an important outcome for studying the processes that affect the cosmic-ray flux that reaches Earth. But theres an additional intriguing consequence of this result: knowledge of the current solar activity could allow us to predict the modulation that will occur for cosmic rays near Earth an entire 8 months from now! If this model is correct, it brings us one step closer to being able to plan safer space missions for the future.CitationNicola Tomassetti et al 2017 ApJL 849 L32. doi:10.3847/2041-8213/aa9373
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pohl, M.; /Iowa State U.; Abdo, Aous A.
This is a report on the findings of the SNR/cosmic-ray working group for the white paper on the status and future of ground-based gamma-ray astronomy. The white paper is an APS commissioned document, and the overall version has also been released and can be found on astro-ph. This detailed section of the white paper discusses the status of past and current attempts to observe shell-type supernova remnants and diffuse emission from cosmic rays at GeV-TeV energies. We concentrate on the potential of future ground-based gamma-ray experiments to study the acceleration of relativistic charged particles which is one of the mainmore » unsolved, yet fundamental, problems in modern astrophysics. The acceleration of particles relies on interactions between energetic particles and magnetic turbulence. In the case of SNRs we can perform spatially resolved studies in systems with known geometry, and the plasma physics deduced from these observations will help us to understand other systems where rapid particle acceleration is believed to occur and where observations as detailed as those of SNRs are not possible.« less
Minimum length Pb/SCIN detector for efficient cosmic ray identification
NASA Technical Reports Server (NTRS)
Snyder, H. David
1989-01-01
A study was made of the performance of a minimal length cosmic ray shower detector that would be light enough for space flight and would provide efficient identification of positions and protons. Cosmic ray positions are mainly produced in the decay chain of: Pion yields Muon yields Positron and they provide a measure of the matter density traversed by primary protons. Present positron flux measurements are consistent with the Leaky Box and Halo models for sources of cosmic rays. Abundant protons in the space environment are a significant source of background that would wash out the positron signal. Protons and positrons produced very distictive showers of particles when they enter matter; many studies have been published on their behavior on large calorimeter detectors. The challenge is to determine the minimal material necessary (minimal calorimeter depth) for positive particles identification. The primary instrument for the investigation is the Monte Carlo code GEANT, a library of programs from CERN that can be used to model experimental geometry, detector responses and particle interaction processes. The use of the Monte Carlo approach is crucial since statistical fluctuations in shower shape are significant. Studies conducted during the 1988 summer program showed that straightforward approaches to the problem achieved 85 to 90 percent correct identification, but left a residue of 10 to 15 percent misidentified particles. This percentage improved to a few percent when multiple shower-cut criteria were applied to the data. This summer, the same study was extended to employ several physical and statistical methods of identifying response of the calorimeter and the efficiency of the optimal shower cuts to off-normal incidence particle was determined.
Nineteenth International Cosmic Ray Conference. HE Sessions, Volume 8
NASA Technical Reports Server (NTRS)
Jones, F. C. (Compiler)
1985-01-01
Papers submitted for presentation at the 19th International Cosmic Ray Conference are compiled. The present volume contains papers addressing high energy interactions and related phenomena. Specific topic areas include muons, neutrinos, magnetic monopoles, nucleon decay, searches for new particles, and acoustic and thermoluminescence detection techniques.
Locating chambers in an Egyptian pyramid using cosmic ray muons
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lynch, G.R.
From symposium on advanced technology arising from particle physics research; Argonne, Illinois, USA (17 May 1973). A brief report is given on the attempt to detect a chamber or chambers in the Second Pyramid of Chephen at Giza by using cosmic-ray muons. (WDM)
Onion-shell model for cosmic ray electrons and radio synchrotron emission in supernova remnants
NASA Technical Reports Server (NTRS)
Beck, R.; Drury, L. O.; Voelk, H. J.; Bogdan, T. J.
1985-01-01
The spectrum of cosmic ray electrons, accelerated in the shock front of a supernova remnant (SNR), is calculated in the test-particle approximation using an onion-shell model. Particle diffusion within the evolving remnant is explicity taken into account. The particle spectrum becomes steeper with increasing radius as well as SNR age. Simple models of the magnetic field distribution allow a prediction of the intensity and spectrum of radio synchrotron emission and their radial variation. The agreement with existing observations is satisfactory in several SNR's but fails in other cases. Radiative cooling may be an important effect, especially in SNR's exploding in a dense interstellar medium.
Design and Characteristics of the Anticoincidence Detector for the GLAST Large Area Telescope
NASA Technical Reports Server (NTRS)
Moiseev, A. A.; Hartman, R. C.; Johnson, T. E.; Ormes, J. F.; Thompson, D. J.
2005-01-01
The Anti-Coincidence Detector (ACD) is the outermost detector layer in the GLAST Large Area Telescope (LAT), surrounding the top and sides of the tracker. The purpose of the ACD is to detect and veto incident cosmic ray charged particles, which outnumber cosmic gamma rays by 3-4 orders of magnitude. The challenge in ACD design is that it must have high (0.9997) detection efficiency for singly charged relativistic particles, but must also have low sensitivity to backsplash particles. These are products of high- energy interactions in the LAT calorimeter. They can cause a veto signal in the ACD, resulting in loss of good gamma-ray events.
Systems for detecting charged particles in object inspection
Morris, Christopher L.; Makela, Mark F.
2013-08-20
Techniques, apparatus and systems for detecting particles such as muons. In one implementation, a monitoring system has a cosmic ray-produced charged particle tracker with a plurality of drift cells. The drift cells, which can be for example aluminum drift tubes, can be arranged at least above and below a volume to be scanned to thereby track incoming and outgoing charged particles, such as cosmic ray-produced muons, while also detecting gamma rays. The system can selectively detect devices or materials, such as iron, lead, gold and/or tungsten, occupying the volume from multiple scattering of the charged particles passing through the volume and can also detect any radioactive sources occupying the volume from gamma rays emitted therefrom. If necessary, the drift tubes can be sealed to eliminate the need for a gas handling system. The system can be employed to inspect occupied vehicles at border crossings for nuclear threat objects.
NASA Astrophysics Data System (ADS)
Vieregg, Abigail
Through high energy neutrino astrophysics, we explore the structure and evolution of the universe in a unique way and learn about the physics inside of astrophysical sources that drives the acceleration of the highest energy particles. Neutrinos travel virtually unimpeded through the universe, making them unique messenger particles for cosmic sources and carrying information about very distant sources that would otherwise be unavailable. The highest energy neutrinos (E>10^{18} eV), created as a by-product of the interaction of the highest energy cosmic rays with the cosmic microwave background, are an important tool for determining the origin of the highest energy cosmic rays and still await discovery. Balloon-borne and ground-based experiments are poised to discover these ultra-high energy (UHE) cosmogenic neutrinos by looking for radio emission from two different types of neutrino interactions: particle cascades induced by neutrinos in glacial ice, and extensive air showers in the atmosphere induced by the charged-particle by-product of tau neutrinos interacting in the earth. These impulsive radio detectors are also sensitive to radio emission from extensive air showers induced directly by UHE cosmic rays. Balloon-borne experiments are especially well-suited for discovering the highest energy neutrinos, and are the only way to probe the high energy cutoff of the sources themselves to reveal the astrophysics that drives the central engines inside the most energetic accelerators in the universe. Balloon platforms offer the chance to monitor extremely large volumes of ice and atmosphere, but with a higher energy threshold compared to ground-based observatories, since the neutrino interaction happens farther from the detector. This tradeoff means that the sensitivity of balloon-borne experiments, such as the Antarctic Impulsive Transient Antenna (ANITA) or the ExaVolt Antenna, is optimized for discovery of the highest energy neutrinos. We are developing an interferometric phased array trigger for these impulsive radio detectors, a new type of trigger that will improve sensitivity substantially and expedite the discovery of the highest energy particles in our universe. We have developed an 8- channel interferometric trigger board for ground-based applications that will be deployed in December 2017 with the ground-based Askaryan Radio Array (ARA) experiment at the South Pole. Preliminary Monte Carlo simulations indicate that the cosmogenic neutrino event rate will go up by a factor of 3 with the new trigger. The true power of the interferometric trigger is in scaling to large numbers of channels, and the discovery space that is only available from a balloon platform at the highest energies is extremely appealing. We will build on and extend the NASA investment in the ANITA Long Duration Balloon (LDB) mission and the many other complementary particle astrophysics LDB missions by developing the electronics required to bring a large-scale radio interferometric trigger to a balloon platform, extending the scientific reach of any future LDB or Super Pressure Balloon (SPB) mission for radio detection of the highest energy cosmic particles. We will develop an interferometric trigger system that is scalable to O(100) channels and suitable for use on a balloon platform. Under this proposal, we will: 1) Design and fabricate interferometric trigger hardware for balloon-borne cosmic particle detectors that is scalable to large numbers of channels O(100) by reducing the power consumption per channel, increasing the number of channels per board, and developing high-speed communication capability between boards. 2) Perform a trade study and inform design decisions for future balloon missions by further developing our Monte Carlo simulation and adapting it to balloon geometries.
Cosmic string lensing and closed timelike curves
NASA Astrophysics Data System (ADS)
Shlaer, Benjamin; Tye, S.-H. Henry
2005-08-01
In an analysis of the gravitational lensing by two relativistic cosmic strings, we argue that the formation of closed timelike curves proposed by Gott is unstable in the presence of particles (e.g. the cosmic microwave background radiation). Because of the attractorlike behavior of the closed timelike curve, we argue that this instability is very generic. A single graviton or photon in the vicinity, no matter how soft, is sufficient to bend the strings and prevent the formation of closed timelike curves. We also show that the gravitational lensing due to a moving cosmic string is enhanced by its motion, not suppressed.
The basis for cosmic ray feedback: Written on the wind
Zweibel, Ellen G.
2017-01-01
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. PMID:28579734
The basis for cosmic ray feedback: Written on the wind
NASA Astrophysics Data System (ADS)
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.
The basis for cosmic ray feedback: Written on the wind.
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.
Evidence for confinement of low-energy cosmic rays ahead of interplanetary shock waves.
NASA Technical Reports Server (NTRS)
Palmeira, R. A. R.; Allum, F. R.
1973-01-01
Short-lived (about 15 min), low-energy proton increases associated with the passage of interplanetary shock waves have been previously reported. In the present paper, we have examined in a fine time scale (about 1 min) the concurrent particle and magnetic field data, taken by detectors on Explorer 34, for four of these events. Our results further support the view that these impulsive events are due to confinement of the solar cosmic-ray particles in the region just ahead (about 1,000,000 km) of the advancing shock front.
Time-dependent evolution of cosmic-ray-modified shock structure: Transition to steady state
NASA Astrophysics Data System (ADS)
Donohue, D. J.; Zank, G. P.; Webb, G. M.
1994-03-01
Steady state solutions to the two-fluid equations of cosmic-ray-modified shock structure were investigated first by Drury and Volk (1981). Their analysis revealed, among other properties, that there exist regions of upstream parameter space where the equations possess three different downstream solutions for a given upstream state. In this paper we investigate whether or not all these solutions can occur as time-asymptotic states in a physically realistic evolution. To do this, we investigate the time-dependent evolution of the two-fluid cosmic-ray equations in going from a specified initial condition to a steady state. Our results indicate that the time-asymptotic solution is strictly single-valued, and it undergoes a transition from weakly to strongly cosmic-ray-modified at a critical value of the upstream cosmic ray energy density. The expansion of supernova remnant shocks is considered as an example, and it is shown that the strong to weak transition is in fact more likely. The third intermediate solution is shown to influence the time-dependent evolution of the shock, but it is not found to be a stable time-asymptotic state. Timescales for convergence to these states and their implications for the efficiency of shock acceleration are considered. We also investigate the effects of a recently introduced model for the injection of seed particles into the shock accelerated cosmic-ray population. The injection is found to result in a more strongly cosmic-ray-dominated shock, which supports our conclusion that for most classes of intermediate and strong cosmic-ray-modified shocks, the downstream cosmic-ray pressure component is at least as large as the thermal gas pressure, independent of the upstream state. As a result, cosmic rays almost always play a significant role in determining the shock structure and dissipation and they cannot be regarded as test particles.
Time-dependent evolution of cosmic-ray-modified shock structure: Transition to steady state
NASA Technical Reports Server (NTRS)
Donohue, D. J.; Zank, G. P.; Webb, G. M.
1994-01-01
Steady state solutions to the two-fluid equations of cosmic-ray-modified shock structure were investigated first by Drury and Volk (1981). Their analysis revealed, among other properties, that there exist regions of upstream parameter space where the equations possess three different downstream solutions for a given upstream state. In this paper we investigate whether or not all these solutions can occur as time-asymptotic states in a physically realistic evolution. To do this, we investigate the time-dependent evolution of the two-fluid cosmic-ray equations in going from a specified initial condition to a steady state. Our results indicate that the time-asymptotic solution is strictly single-valued, and it undergoes a transition from weakly to strongly cosmic-ray-modified at a critical value of the upstream cosmic ray energy density. The expansion of supernova remnant shocks is considered as an example, and it is shown that the strong to weak transition is in fact more likely. The third intermediate solution is shown to influence the time-dependent evolution of the shock, but it is not found to be a stable time-asymptotic state. Timescales for convergence to these states and their implications for the efficiency of shock acceleration are considered. We also investigate the effects of a recently introduced model for the injection of seed particles into the shock accelerated cosmic-ray population. The injection is found to result in a more strongly cosmic-ray-dominated shock, which supports our conclusion that for most classes of intermediate and strong cosmic-ray-modified shocks, the downstream cosmic-ray pressure component is at least as large as the thermal gas pressure, independent of the upstream state. As a result, cosmic rays almost always play a significant role in determining the shock structure and dissipation and they cannot be regarded as test particles.
Cosmic-ray tracks in plastics: the apollo helmet dosimetry experiment.
Comstock, G M; Fleischer, R L; Giard, W R; Hart, H R; Nichols, G E; Price, P B
1971-04-09
Counts of tracks from heavy cosmic-ray nuclei in helmets from Apollo missions 8 and 12 show variations caused by solar modulation of the galactic cosmic-ray flux. Specific estimates of the biological damage to certain nonreplaceable cells by track-forming particles during these space missions indicate that the fraction of deactivated cells could range from a lower limit of 3 x 10(-7) to an upper limit of 1.4 x 10(-4).
Observation of cosmic-ray particles with Z greater than 35.
NASA Technical Reports Server (NTRS)
Blanford, G. E., Jr.; Friedlander, M. W.; Klarmann, J.; Pomeroy, S. S.; Walker, R. M.; Wefel, J. P.; Fowler, P. H.; Kidd, J. M.; Kobetich, E. J.; Moses, R. T.
1973-01-01
The results of two flights conducted in Texas in September 1968 are reported, giving attention to experimental details, the charge spectrum, and the primary flux of very very heavy cosmic rays. Considerable interest is attached to the observation of uranium, thorium, and transuranic nuclei in the cosmic radiation. It is found that the relative abundances of the charge groups in the ranges from 35 to 40 and from 41 to 50 deviate significantly from solar system abundances.
Constraints on cosmic superstrings from Kaluza-Klein emission.
Dufaux, Jean-François
2012-07-06
Cosmic superstrings interact generically with a tower of light and/or strongly coupled Kaluza-Klein (KK) modes associated with the geometry of the internal space. We study the production of KK particles by cosmic superstring loops, and show that it is constrained by big bang nucleosynthesis. We study the resulting constraints in the parameter space of the underlying string theory model and highlight their complementarity with the regions that can be probed by current and upcoming gravitational wave experiments.
Observing Short-wave Infrared Atmospheric Fluorescence Near Radioactive Sources: A Feasibility Study
2014-03-17
Defense Threat Reduction Agency Ft. Belvoir, VA 22060 76-4184-32-5 MIPR HDTRA 124655 1NRC Postdoctoral Research Associate Contents 1 Introduction 1 2...a desire to measure cosmic ray effects. For example, the pioneering study of cosmic ray detection by fluorescence was by Bunner in 1967 wherein he...wavelengths, the ultra-high energy cosmic ray (UHECR) community has continued to pursue studies of the fluorescence yield from high energy particle impact on
Cosmic strings and ultra-high energy cosmic rays
NASA Technical Reports Server (NTRS)
Bhattacharjee, Pijushpani
1989-01-01
The flux is calculated of ultrahigh energy protons due to the process of cusp evaporation from cosmic string loops. For the standard value of the dimensionless cosmic string parameter epsilon is identical to G(sub mu) approx. = 10(exp -6), the flux is several orders of magnitude below the observed cosmic ray flux of ultrahigh energy protons. However, the flux at any energy initially increases as the value of epsilon is decreased. This at first suggests that there may be a lower limit on the value of epsilon, which would imply a lower limit on the temperature of a cosmic string forming phase transition in the early universe. However, the calculation shows that this is not the case -- the particle flux at any energy reaches its highest value at epsilon approx. = 10(exp -15) and it then decreases for further decrease of the value of epsilon. This is due to the fact that for too small values of epsilon (less than 10(exp -15)), the energy loss of the loops through the cusp evaporation process itself (rather than gravitational energy loss of the loops) becomes the dominant factor that controls the behavior of the number density of the loops at the relevant times of emission of the particles. The highest flux at any energy remains at least four orders of magnitude below the observed flux. There is thus no lower limit on epsilon.
The Status and Recent Results of the Telescope Array Experiment
NASA Astrophysics Data System (ADS)
Yamazaki, Katsuya
The Telescope Array (TA) is a cosmic ray observatory of the largest aperture in the northern hemisphere, located in a desert in the western part of Utah, U.S.A., to explore the origin of ultrahigh energy cosmic rays, photons, and neutrinos. The TA employs two types of detectors to observe air showers generated by cosmic rays in the atmosphere: the first is a "surface detector (SD)" of scintillation counters to measure shower particles on the ground, and the second is a "fluorescence detector (FD)" of telescopes installed in three stations to observe fluorescence light, caused by air shower particles, from the atmosphere above the SD array. The TA detectors have been in routine operation since May 2008. We measured the energy spectrum of cosmic rays with energy greater than 1018 eV from our first 4-year data. We found a clear suppression of comic ray intensity above 5 × 1019 eV. This feature is consistent with a theoretical prediction that cosmic rays lose energies due to interaction with cosmic microwave background photons during propagation in the intergalactic space. In this talk, We will present the status of the TA experiment and the recent results, including the energy spectrum, study of the primary mass composition, and searches for anisotropies in the arrival directions. We also briefly describe plans for further extensions.
Extensive Air Showers in the Classroom
ERIC Educational Resources Information Center
Badala, A.; Blanco, F.; La Rocca, P.; Pappalardo, G. S.; Pulvirenti, A.; Riggi, F.
2007-01-01
The basic properties of extensive air showers of particles produced in the interaction of a high-energy primary cosmic ray in the Earth's atmosphere are discussed in the context of educational cosmic ray projects involving undergraduate students and high-school teams. Simulation results produced by an air shower development code were made…
NASA Astrophysics Data System (ADS)
Bazhutov, Yu. N.; Baranov, D. S.
2001-08-01
There are presented the first results of the new heavy stable cosmic ray particles search in the bubble chamber "SKAT" (450 x 160 x 90 cm3 ), which was exposed in the neutrino beam of Serpukhov Accelerator during 1976 - 1992 years and was viewed along the horizontal direction so as the magnet field direction (MDM > 150 GeV/c). From looking over 1,270 stills (1 roll for April 23, 1979) it was selected 757 tracks of cosmic ray particles with zenith angle θ < 45°, track length - L > 50 cm and momentum P>2.0GeV/c. From this events there were constructed momentum spectrums for both negative and positive vertical cosmic ray penetrating particles in the (2.0 - 126) GeV/c range and calculated their charge ratio. For positive particles the momentum spectrum has normal shape in all studied range the same as for negative particles but only for momentum range (2.0 - 32) GeV/c and charge ratio for this range is normal and the same as for cosmic muons. But for momentum P>32GeV/c it was observed negative particles excess flux (~10-5 cm-2 s-1 sr-1 ) with changed charge ratio - R = 0.62 +/0.18 (˜>3.5σ) for momentum range (32GeV/c
3σ) and for momentum range (3.6GeV/c
107 cm2 ṡsṡsr); 2) the installation place must be on the Earth surface or small underground (< 100 m.w.e.); 3) it is desirable to use track detector for event and particle charge viewing. One of the largest Bubble Chamber "SKAT" (BC), operated from 1976 to 1992 on the Serpukhov Accelerator neutrino beam had satisfied to all these demands. Its operation on the neutrino beam could provide a small background from Accelerator fo r our researches. Accumulated ~ 4 x 2,000,000 stills inside ~ 4 x 1660 rolls during this long period were conserved until now and were ready to analysis. The large Bubble Chamber (450 x 160 x 90 cm3 ) had been placed in greatest magnetic field (17 kG) horizontally directed so as coaxial to it view of 4 stereo photo chambers. So near vertical penetrating cosmic rays could be registered the same as near horizontal neutrino beam events. Full "SKAT" exposition is S-T ~ 4ṡ109 cm2 ṡsṡsr , that is rather more demanded one. It provides us for charge and momentum (MDM > 150 GeV/c) measurements. BC had been placed on the Earth surface, but had large magnetic iron screen (d ~ 2500 g/cm2 = 25m.w.e., Fig.1).
Compositions of energetic particle populations in interplanetary space
NASA Technical Reports Server (NTRS)
Gloeckler, G.
1979-01-01
Observations of helium and heavier particles with energies below about 10 to 20 MeV/nucleon are discussed with emphasis on the composition of solar flare particles, corotating energetic particle streams, and the anomalous cosmic ray component. Future advances expected from results obtained from ISEE -3, Voyager, and the international solar polar spacecraft are reviewed.
Observation of arrival times of EAS with energies or = 6 x 10 (14) eV
NASA Technical Reports Server (NTRS)
Sun, L.
1985-01-01
The Earth's atmosphere is continually being bombarded by primary cosmic ray particles which are generally believed to be high-energy nuclei. The fact that the majority of cosmic ray primaries are charged particles and that space is permeated with random magnetic fields, means that the particles do not travel in straight lines. The arrival time distribution of EAS may also transfer some information about the primary particles. Actually, if the particles come to our Earth in a completely random process, the arrival time distribution of pairs of successive particles should fit an exponential law. The work reported here was arried out at Sydney University from May 1982 to January 1983. All the data are used to plot the arrival-time distribution of the events, that is, the distribution of time-separation between consecutive events on a 1 minute bin size. During this period more than 2300 showers were recorded. The results are discussed and compared with that of some other experiments.
On the spectrum of stable secondary nuclei in cosmic rays
NASA Astrophysics Data System (ADS)
Blasi, P.
2017-10-01
The ratio of the fluxes of secondary and primary nuclei in cosmic rays has long been used as an indicator of the grammage traversed in the journey of cosmic ray particles throughout the Galaxy. The basic idea is that primary particles are accelerated in astrophysical sources, such as supernova remnant shocks and eventually propagate in the Galactic volume, occasionally interacting with gas, mainly in the disc of the Galaxy, and there they produce secondary nuclei through spallation. At sufficiently high energy, typically ≳100 GeV/n, the ratio of fluxes of the secondary nucleus to that of the main primary nucleus is found to scale as Ek^{-δ }, where Ek is the energy per nucleon (a conserved quantity in spallation reactions) and δ identifies the energy dependence of the diffusion coefficient. The same shock waves that may be responsible for cosmic ray acceleration in the first place also pick up any other charged particle in the upstream, provided being above threshold for injection. The secondary nuclei produced by spallation in the interstellar medium are no exception, hence they also get accelerated. This effect is unavoidable, only its strength may be subject of debate. We compute the spectrum of secondary elements such as boron and lithium taking into account shock reacceleration and compare our predictions with the recent observations of the B/C ratio and preliminary measurements of the boron and lithium flux. Both these sets of data seem to confirm that reacceleration of secondary nuclei indeed plays an important role, thereby affecting the validity of those scaling rules that are often used in cosmic ray physics.
Rossi and high-energy astronomy
NASA Astrophysics Data System (ADS)
Clark, George W.
2012-03-01
The contributions of Bruno Rossi to high-energy astronomy began in Italy in the 1930s with investigations concerning the nature of cosmic rays in theory and in hands-on experiments at the universities of Florence and Padua. Recent discoveries had cast doubt on Robert Millikan's idea that the primary cosmic rays are gamma rays created in the production of the elements by fusion of hydrogen atoms in interstellar space. Rossi entered the field with a prediction published in 1930 of a difference between the intensity of cosmic rays from the east and the west that would occur if the primary cosmic rays were charged particles of one sign. In the same year he invented the first practical electronic coincidence circuit, which he used in a series of fundamental particle experiments and in an unsuccessful attempt to detect an east-west effect at Florence. Expecting by theory that the effect would be greater at high altitude near the equator, he took his experiment to Eritrea in 1934 where his measurements demonstrated that the primary cosmic rays are predominantly positive particles. In the report of his expedition he also described his discovery of extensive cosmic-ray air showers. After WWII and his work at Los Alamos, Rossi resumed his cosmic-ray research, now at MIT, in a new style best described in his own words: ``Now I had the responsibility of an entire group, and what mattered was no longer my own work, but the work of the group.'' He suggested the new methods of ``density sampling'' and ``fast timing'' for air shower studies, and promoted their application in numerous experiments on the nature and origins of the highest energy cosmic rays. In 1959 he initiated and participated as a consultant in the work of Riccardo Giacconi that led to the discovery of the first x-ray star, Sco X-1, and the development of the first imaging x-ray telescopes. At MIT, members of the Rossi Cosmic Ray Group took the early steps in gamma-ray astronomy, first with balloon experiments that set lower and lower limits on the intensity of primary gamma rays, and then with the satellite experiments led by William Kraushaar that discovered the galactic and extra-galactic components of cosmic gamma rays. After Sco X-1, Rossi focused his efforts on exploring the solar wind and the interplanetary plasma while leaving his younger colleagues to pursue the new field of extra-solar x-ray astronomy with balloon, rocket, and satellite experiments.
NASA Astrophysics Data System (ADS)
Strauss, R. Du Toit; Effenberger, Frederic
2017-10-01
In this review, an overview of the recent history of stochastic differential equations (SDEs) in application to particle transport problems in space physics and astrophysics is given. The aim is to present a helpful working guide to the literature and at the same time introduce key principles of the SDE approach via "toy models". Using these examples, we hope to provide an easy way for newcomers to the field to use such methods in their own research. Aspects covered are the solar modulation of cosmic rays, diffusive shock acceleration, galactic cosmic ray propagation and solar energetic particle transport. We believe that the SDE method, due to its simplicity and computational efficiency on modern computer architectures, will be of significant relevance in energetic particle studies in the years to come.
Milky Way's Super-efficient Particle Accelerators Caught in The Act
NASA Astrophysics Data System (ADS)
2009-06-01
Thanks to a unique "ballistic study" that combines data from ESO's Very Large Telescope and NASA's Chandra X-ray Observatory, astronomers have now solved a long-standing mystery of the Milky Way's particle accelerators. They show in a paper published today on Science Express that cosmic rays from our galaxy are very efficiently accelerated in the remnants of exploded stars. During the Apollo flights astronauts reported seeing odd flashes of light, visible even with their eyes closed. We have since learnt that the cause was cosmic rays - extremely energetic particles from outside the Solar System arriving at the Earth, and constantly bombarding its atmosphere. Once they reach Earth, they still have sufficient energy to cause glitches in electronic components. Galactic cosmic rays come from sources inside our home galaxy, the Milky Way, and consist mostly of protons moving at close to the speed of light, the "ultimate speed limit" in the Universe. These protons have been accelerated to energies exceeding by far the energies that even CERN's Large Hadron Collider will be able to achieve. "It has long been thought that the super-accelerators that produce these cosmic rays in the Milky Way are the expanding envelopes created by exploded stars, but our observations reveal the smoking gun that proves it", says Eveline Helder from the Astronomical Institute Utrecht of Utrecht University in the Netherlands, the first author of the new study. "You could even say that we have now confirmed the calibre of the gun used to accelerate cosmic rays to their tremendous energies", adds collaborator Jacco Vink, also from the Astronomical Institute Utrecht. For the first time Helder, Vink and colleagues have come up with a measurement that solves the long-standing astronomical quandary of whether or not stellar explosions produce enough accelerated particles to explain the number of cosmic rays that hit the Earth's atmosphere. The team's study indicates that they indeed do and it directly tells us how much energy is removed from the shocked gas in the stellar explosion and used to accelerate particles. "When a star explodes in what we call a supernova a large part of the explosion energy is used for accelerating some particles up to extremely high energies", says Helder. "The energy that is used for particle acceleration is at the expense of heating the gas, which is therefore much colder than theory predicts". People Who Read This Also Read... NASA Announces 2009 Astronomy and Astrophysics Fellows Cosmic Heavyweights in Free-for-all Galaxies Coming of Age in Cosmic Blobs Oldest Known Objects Are Surprisingly Immature The researchers looked at the remnant of a star that exploded in AD 185, as recorded by Chinese astronomers. The remnant, called RCW 86, is located about 8200 light-years away towards the constellation of Circinus (the Drawing Compass). It is probably the oldest record of the explosion of a star. Using ESO's Very Large Telescope, the team measured the temperature of the gas right behind the shock wave created by the stellar explosion. They measured the speed of the shock wave as well, using images taken with NASA's X-ray Observatory Chandra three years apart. They found it to be moving at between 10 and 30 million km/h, between 1 and 3 percent the speed of light. The temperature of the gas turned out to be 30 million degrees Celsius. This is quite hot compared to everyday standards, but much lower than expected, given the measured shock wave's velocity. This should have heated the gas up to at least half a billion degrees. "The missing energy is what drives the cosmic rays", concludes Vink.
Unmelted cosmic metal particles in the Indian Ocean
NASA Astrophysics Data System (ADS)
Shyam Prasad, Mokkapati; Rudraswami, N. G.; De Araujo, Agnelo A.; Khedekar, Vijay D.
2017-06-01
Fe-Ni metal is a common constituent of most meteorites and is an indicator of the thermal history of the respective meteorites, it is a diagnostic tool to distinguish between groups/subgroups of meteorites. In spite of over a million micrometeorites collected from various domains, reports of pure metallic particles among micrometeorites have been extremely rare. We report here the finding of a variety of cosmic metal particles such as kamacite, plessite, taenite, and Fe-Ni beads from deep-sea sediments of the Indian Ocean, a majority of which have entered the Earth unaffected by frictional heating during atmospheric entry. Such particles are known as components of meteorites but have never been found as individual entities. Their compositions suggest precursors from a variety of meteorite groups, thus providing an insight into the metal fluxes on the Earth. Some particles have undergone heating and oxidation to different levels during entry developing features similar to I-type cosmic spherules, suggesting atmospheric processing of individual kamacites/taenite grains as another hitherto unknown source for the I-type spherules. The particles have undergone postdepositional aqueous alteration transforming finally into the serpentine mineral cronstedtite. Aqueous alteration products of kamacite reflect the local microenvironment, therefore they have the potential to provide information on the composition of water in the solar nebula, on the parent bodies or on surfaces of planetary bodies. Our observations suggest it would take sustained burial in water for tens of thousands of years under cold conditions for kamacites to alter to cronstedtite.
Apollo-Soyuz pamphlet no. 6: Cosmic ray dosage. [experimental designiradiation hazards and dosage
NASA Technical Reports Server (NTRS)
Page, L. W.; From, T. P.
1977-01-01
The radiation hazard inside spacecraft is discussed with emphasis on its effects on the crew, biological specimens, and spacecraft instruments. The problem of light flash sensations in the eyes of astronauts is addressed and experiment MA-106 is described. In this experiment, light flashes seen by blindfolded astronauts were counted and high energy cosmic ray intensity in the command module cabin were measured. The damage caused by cosmic ray hits on small living organisms was investigated in the Biostack 3 experiment (MA-107). Individual cosmic rays were tracked through layers of bacterial spores, small seeds, and eggs interleaved with layers of AgCl-crystal wafers, special plastic, and special photographic film that registered each cosmic ray particle passed.
Measuring the Cosmic Particle Radiation from electrons to actinides - HNX/TIGERISS
NASA Astrophysics Data System (ADS)
Mitchell, John
2017-01-01
The Heavy Nuclei eXplorer (HNX) mission will measure the abundances of nuclei from Carbon (Z =6) to Curium (Z =96) in the cosmic radiation with the resolution to identify the atomic number of each detected nucleus. HNX will measure a significant number of actinides. HNX utilizes two high-precision instruments, the Extremely-heavy Cosmic-ray Composition Observer (ECCO) and the Cosmic-Ray Trans-Iron Galactic Element Recorder (CosmicTIGER), located in a SpaceX DragonLab capsule orbiting the Earth. This talk will discuss the motivating science, the HNX mission, the design and performance of the HNX instruments, and another new instrument, TIGERISS (Trans-Iron Galactic Element Recorder on the ISS), that will be proposed as an intermediate between SuperTIGER and HNX.
NASA Technical Reports Server (NTRS)
Divine, N.
1975-01-01
The design of space vehicles for operation in interplanetary space is given, based on descriptions of solar wind, solar particle events, and galactic cosmic rays. A state-of-the-art review is presented and design criteria are developed from experiment findings aboard interplanetary and high-altitude earth-orbiting spacecraft. Solar cells were found to be particularly sensitive. Solar protons may also impact the reliability of electric propulsion systems and spacecraft surfaces, as well as causing interference, detector saturation, and spurious signals. Galactic cosmic-ray impact can lead to similar electronic failure and interference and may register in photographic films and other emulsions. It was concluded that solar wind electron measurements might result from differential charging when shadowed portions of the spacecraft acquired a negative charge from electron impact.
The Pierre Auger Cosmic Ray Observatory
Aab, Alexander
2015-07-08
The Pierre Auger Observatory, located on a vast, high plain in western Argentina, is the world's largest cosmic ray observatory. The objectives of the Observatory are to probe the origin and characteristics of cosmic rays above 1017 eV and study the interactions of these, the most energetic particles observed in nature. The Auger design features an array of 1660 water Cherenkov particle detector stations spread over 3000 km 2 overlooked by 24 air fluorescence telescopes. Additionally, three high elevation fluorescence telescopes overlook a 23.5 km 2, 61-detector infilled array with 750 m spacing. The Observatory has been in successful operationmore » since completion in 2008 and has recorded data from an exposure exceeding 40,000 km 2 sr yr. This paper describes the design and performance of the detectors, related subsystems and infrastructure that make up the Observatory.« less
Future Experiments in Astrophysics
NASA Technical Reports Server (NTRS)
Krizmanic, John F.
2002-01-01
The measurement methodologies of astrophysics experiments reflect the enormous variation of the astrophysical radiation itself. The diverse nature of the astrophysical radiation, e.g. cosmic rays, electromagnetic radiation, and neutrinos, is further complicated by the enormous span in energy, from the 1.95 Kappa relic neutrino background to cosmic rays with energy greater than 10(exp 20)eV. The measurement of gravity waves and search for dark matter constituents are also of astrophysical interest. Thus, the experimental techniques employed to determine the energy of the incident particles are strongly dependent upon the specific particles and energy range to be measured. This paper summarizes some of the calorimetric methodologies and measurements planned by future astrophysics experiments. A focus will be placed on the measurement of higher energy astrophysical radiation. Specifically, future cosmic ray, gamma ray, and neutrino experiments will be discussed.
Novel Cosmic-Ray Electron and Positron Constraints on MeV Dark Matter Particles.
Boudaud, Mathieu; Lavalle, Julien; Salati, Pierre
2017-07-14
MeV dark matter (DM) particles annihilating or decaying to electron-positron pairs cannot, in principle, be observed via local cosmic-ray (CR) measurements because of the shielding solar magnetic field. In this Letter, we take advantage of spacecraft Voyager 1's capacity for detecting interstellar CRs since it crossed the heliopause in 2012. This opens up a new avenue to probe DM in the sub-GeV energy/mass range that we exploit here for the first time. From a complete description of the transport of electrons and positrons at low energy, we derive predictions for both the secondary astrophysical background and the pair production mechanisms relevant to DM annihilation or decay down to the MeV mass range. Interestingly, we show that reacceleration may push positrons up to energies larger than the DM particle mass. We combine the constraints from the Voyager and AMS-02 data to get novel limits covering a very extended DM particle mass range, from MeV to TeV. In the MeV mass range, our limits reach annihilation cross sections of order ⟨σv⟩∼10^{-28} cm^{3}/s. An interesting aspect is that these limits barely depend on the details of cosmic-ray propagation in the weak reacceleration case, a configuration which seems to be favored by the most recent B/C data. Though extracted from a completely different and new probe, these bounds have a strength similar to those obtained with the cosmic microwave background-they are even more stringent for p-wave annihilation.
Analysis of Cosmic Spherule Candidates from the Kwajalein Micrometeorite Collection
NASA Technical Reports Server (NTRS)
Wozniakiewicz, P. J.; Price, M. C.; Bradley, J. P.; Ishii, H. A.; Russell, S. S.; Zolensky, M. E.; Brownlee, D. E.
2015-01-01
The Kwajalein micrometeorite collection utilised high volume air samplers fitted with 5 micrometer laser-etched polycarbonate membrane filters to capture particles directly from the atmosphere. The filters were changed weekly over several months throughout 2011/12, providing the opportunity to investigate the contemporary flux of micrometeorites. We recently reported the results of our initial survey of cosmic spherule-like particles on several of these filters. We identified three main groups of particle based on bulk compositions: 1. Silicate spherules rich in Mg, Ca and Fe, 2. Silicate spherules rich in Al, Ca, K and/or Na and 3. Fe-rich spherules. Abundances appeared to change over time suggesting links with celestial activity (e.g. meteor showers), however, spherules similar to groups 2 and 3 can be produced by terrestrial and anthropogenic activity (e.g. volcanic microspherules exhibit similar compositions to group 2 spherules and metallic spherules similar to those of group 3 can be formed during fuel combustion). We are now studying the internal structures and chemistries of these spherules and comparing against cosmic spherules identified in other collections to confrim their origins and further contrain the contemporary micrometeorite flux. Particles are being picked, embedded in resin and polished through to reveal their interiors. Here we will describe our ongoing analyses of these particles via SEM. We will also introduce our new collection using this method that is currently being performed in the Antarctic.
Cosmic-ray propagation and containment
NASA Technical Reports Server (NTRS)
Parker, E. N.
1977-01-01
The cosmic rays are an active gaseous component of the disk of the galaxy, and their propagation and containment is a part of the general dynamics of the disk. The sources of cosmic rays are a matter of speculation. The disk is inflated by the cosmic-ray gas pressure, P, comparable to the magnetic pressure B super 2/ 8 pi, but the rate of inflation is unknown. The time spent by the individual cosmic-ray particles in the disk is inversely proportional to the cosmic-ray production rate and may be anything from 100,000 to more than 10 million years. It is evident from the decay of Be(10) that the cosmic rays circulate through a volume of space perhaps ten times the thickness of the gaseous disk, suggesting a magnetic halo extending out approximately 1 kpc from either face of the disk. The cosmic rays may be responsible for the halo by inflating the magnetic fields of the disk. Extension of the fields to 1 kpc would imply a high production rate and short life of cosmic rays in the dense gaseous disk of the galaxy.
Quarks, Leptons, and Bosons: A Particle Physics Primer.
ERIC Educational Resources Information Center
Wagoner, Robert; Goldsmith, Donald
1983-01-01
Presented is a non-technical introduction to particle physics. The material is adapted from chapter 3 of "Cosmic Horizons," (by Robert Wagoner and Don Goldsmith), a lay-person's introduction to cosmology. Among the topics considered are elementary particles, forces and motion, and higher level structures. (JN)
High Energy Astronomy Observatory (HEAO)
1979-09-20
This Atlas/Centaur launch vehicle, carrying the High Energy Astronomy Observatory (HEAO)-3, lifted off on September 20, 1979. The HEAO-3's mission was to survey and map the celestial sphere for gamma-ray flux and make detailed measurements of cosmic-ray particles. It carried three scientific experiments: a gamma-ray spectrometer, a cosmic-ray isotope experiment, and a heavy cosmic-ray nuclei experiment. The HEAO-3 was originally identified as HEAO-C but the designation was changed once the spacecraft achieved orbit.
NASA Astrophysics Data System (ADS)
Takita, Masato
2017-06-01
We have started up the ALPACA (Andes Large area PArticle detector for Cosmic ray physics and Astronomy) project. The ALPACA experiment is composed of an 83,000 m2 air shower array and a 5,400 m2 underground muon detector array to make wide field-of-view high-sensitivity observations of high-energy cosmic rays/cosmic gamma rays on the Cerro Estuqueria highland, 4,740 m above sea level around Mount Chacaltaya, Bolivia. We briefly report on the design concept of the new project and its physics targets.
Cosmic-ray shock acceleration in oblique MHD shocks
NASA Technical Reports Server (NTRS)
Webb, G. M.; Drury, L. OC.; Volk, H. J.
1986-01-01
A one-dimensional, steady-state hydrodynamical model of cosmic-ray acceleration at oblique MHD shocks is presented. Upstream of the shock the incoming thermal plasma is subject to the adverse pressure gradient of the accelerated particles, the J x B force, as well as the thermal gas pressure gradient. The efficiency of the acceleration of cosmic-rays at the shock as a function of the upstream magnetic field obliquity and upstream plasma beta is investigated. Astrophysical applications of the results are briefly discussed.
Effective Dose Equivalent due to Cosmic Ray Particles and Their Secondary Particles on the Moon
NASA Astrophysics Data System (ADS)
Hayatsu, Kanako; Hareyama, Makoto; Kobayashi, Shingo; Karouji, Yuzuru; Sakurai, K.; Sihver, Lembit; Hasebe, N.
Estimation of radiation dose on and under the lunar surface is quite important for human activity on the Moon and for the future lunar bases construction. Radiation environment on the Moon is much different from that on the Earth. Galactic cosmic rays (GCRs) and solar energetic particles (SEPs) directly penetrate the lunar surface because of no atmosphere and no magnetic field around the Moon. Then, they generate many secondary particles such as neutrons, gamma rays and other charged particles by nuclear interactions with soils and regolith breccias under the lunar surface. Therefore, the estimation of radiation dose from them on the surface and the underground of the Moon are essential for safety human activities. In this study, the effective dose equivalents at the surface and various depths of the Moon were estimated using by the latest cosmic rays observation and developed calculation code. The largest contribution to the dose on the surface is primary charged particles in GCRs and SEPs, while in the ground, secondary neutrons are the most dominant. In particular, the dose from neutrons becomes maximal at 70-80 g/cm2 in depth of lunar soil, because fast neutrons with about 1.0 MeV are mostly produced at this depth and give the largest dose. On the lunar surface, the doses originated from large SEPs are very hazardous. We estimated the effective dose equivalents due to such large SEPs and the effects of aluminum shield for the large flare on the human body. In the presentation, we summarize and discuss the improved calculation results of radiation doses due to GCR particles and their secondary particles in the lunar subsurface. These results will provide useful data for the future exploration of the Moon.
Particle Diffusion in Chaotic Magnetic Fields Generated by Asymmetric Current Configurations
NASA Astrophysics Data System (ADS)
Ram, A. K.; Dasgupta, B.
2008-12-01
The observed cross-field diffusion of charged particles in cosmic rays is assumed to be due to the chaotic nature of the interplanetary/intergalactic magnetic fields. Among the classic works on this subject have been those of Parker [1] and Jokipii [2]. Parker considered the passage of cosmic ray particles and energetic solar particles in a large scale magnetic field containing small scale irregularities. In the context of cosmic ray propagation, Jokipii considered a small fluctuating component, added on to a uniform magnetic field, to study the spatial transport of particles. In these studies the irregular component of the magnetic field is prescribed in an ad hoc fashion. In contrast, we consider asymmetric, nonlinear, steady-state magnetic fields, in three spatial dimensions, generated by currents flowing in circular loops and straight lines [3]. These magnetic fields are completely deterministic and, for certain range of parameters, chaotic. We will present analytical and numerical studies on the spatial characteristics of these fields. The motion of charged particles in the nonlinear and chaotic magnetic fields is determined using the Lorentz equation. A particle moving in a deterministic chaotic magnetic field superposed on a uniform background magnetic field is found to undergo spatial transport. This shows that chaotic magnetic fields generated by simple current configurations can produce cross-field diffusion. A detailed analysis of particle motion and diffusion along with application to space plasmas will be presented. [1] E.N. Parker, Planet. Space Sci. 13, 9 (1965). [2] J.R. Jokipii, Astrophys. J. 146, 480 (1966), and J.R. Jokipii, Astrophys. J. 149, 405 (1967). [3] A.K. Ram and B. Dasgupta, Eos Trans. AGU 87 (52), Fall Meet. Suppl. Abstract NG31B-1593 (2006); and Eos Trans. AGU 88 (52), Fall Meet. Suppl. Abstract NG21B-0522 (2007).
Exposure to galactic cosmic radiation and solar energetic particles.
O'Sullivan, D
2007-01-01
Several investigations of the radiation field at aircraft altitudes have been undertaken during solar cycle 23 which occurred in the period 1993-2003. The radiation field is produced by the passage of galactic cosmic rays and their nuclear reaction products as well as solar energetic particles through the Earth's atmosphere. Galactic cosmic rays reach a maximum intensity when the sun is least active and are at minimum intensity during solar maximum period. During solar maximum an increased number of coronal mass ejections and solar flares produce high energy solar particles which can also penetrate down to aircraft altitudes. It is found that the very complicated field resulting from these processes varies with altitude, latitude and stage of solar cycle. By employing several active and passive detectors, the whole range of radiation types and energies were encompassed. In-flight data was obtained with the co-operation of many airlines and NASA. The EURADOS Aircraft Crew in-flight data base was used for comparison with the predictions of various computer codes. A brief outline of some recent studies of exposure to radiation in Earth orbit will conclude this contribution.
Aguilar, M; Ali Cavasonza, L; Alpat, B; Ambrosi, G; Arruda, L; Attig, N; Aupetit, S; Azzarello, P; Bachlechner, A; Barao, F; Barrau, A; Barrin, L; Bartoloni, A; Basara, L; Başeǧmez-du Pree, S; Battarbee, M; Battiston, R; Bazo, J; Becker, U; Behlmann, M; Beischer, B; Berdugo, J; Bertucci, B; Bindi, V; Boella, G; de Boer, W; Bollweg, K; Bonnivard, V; Borgia, B; Boschini, M J; Bourquin, M; Bueno, E F; Burger, J; Cadoux, F; Cai, X D; Capell, M; Caroff, S; Casaus, J; Castellini, G; Cernuda, I; Cervelli, F; Chae, M J; Chang, Y H; Chen, A I; Chen, G M; Chen, H S; Cheng, L; Chou, H Y; Choumilov, E; Choutko, V; Chung, C H; Clark, C; Clavero, R; Coignet, G; Consolandi, C; Contin, A; Corti, C; Coste, B; Creus, W; Crispoltoni, M; Cui, Z; Dai, Y M; Delgado, C; Della Torre, S; Demirköz, M B; Derome, L; Di Falco, S; Dimiccoli, F; Díaz, C; von Doetinchem, P; Dong, F; Donnini, F; Duranti, M; D'Urso, D; Egorov, A; Eline, A; Eronen, T; Feng, J; Fiandrini, E; Finch, E; Fisher, P; Formato, V; Galaktionov, Y; Gallucci, G; García, B; García-López, R J; Gargiulo, C; Gast, H; Gebauer, I; Gervasi, M; Ghelfi, A; Giovacchini, F; Goglov, P; Gómez-Coral, D M; Gong, J; Goy, C; Grabski, V; Grandi, D; Graziani, M; Guerri, I; Guo, K H; Habiby, M; Haino, S; Han, K C; He, Z H; Heil, M; Hoffman, J; Hsieh, T H; Huang, H; Huang, Z C; Huh, C; Incagli, M; Ionica, M; Jang, W Y; Jinchi, H; Kang, S C; Kanishev, K; Kim, G N; Kim, K S; Kirn, Th; Konak, C; Kounina, O; Kounine, A; Koutsenko, V; Krafczyk, M S; La Vacca, G; Laudi, E; Laurenti, G; Lazzizzera, I; Lebedev, A; Lee, H T; Lee, S C; Leluc, C; Li, H S; Li, J Q; Li, J Q; Li, Q; Li, T X; Li, W; Li, Z H; Li, Z Y; Lim, S; Lin, C H; Lipari, P; Lippert, T; Liu, D; Liu, Hu; Lu, S Q; Lu, Y S; Luebelsmeyer, K; Luo, F; Luo, J Z; Lv, S S; Majka, R; Mañá, C; Marín, J; Martin, T; Martínez, G; Masi, N; Maurin, D; Menchaca-Rocha, A; Meng, Q; Mo, D C; Morescalchi, L; Mott, P; Nelson, T; Ni, J Q; Nikonov, N; Nozzoli, F; Nunes, P; Oliva, A; Orcinha, M; Palmonari, F; Palomares, C; Paniccia, M; Pauluzzi, M; Pensotti, S; Pereira, R; Picot-Clemente, N; Pilo, F; Pizzolotto, C; Plyaskin, V; Pohl, M; Poireau, V; Putze, A; Quadrani, L; Qi, X M; Qin, X; Qu, Z Y; Räihä, T; Rancoita, P G; Rapin, D; Ricol, J S; Rodríguez, I; Rosier-Lees, S; Rozhkov, A; Rozza, D; Sagdeev, R; Sandweiss, J; Saouter, P; Schael, S; Schmidt, S M; Schulz von Dratzig, A; Schwering, G; Seo, E S; Shan, B S; Shi, J Y; Siedenburg, T; Son, D; Song, J W; Sun, W H; Tacconi, M; Tang, X W; Tang, Z C; Tao, L; Tescaro, D; Ting, Samuel C C; Ting, S M; Tomassetti, N; Torsti, J; Türkoğlu, C; Urban, T; Vagelli, V; Valente, E; Vannini, C; Valtonen, E; Vázquez Acosta, M; Vecchi, M; Velasco, M; Vialle, J P; Vitale, V; Vitillo, S; Wang, L Q; Wang, N H; Wang, Q L; Wang, X; Wang, X Q; Wang, Z X; Wei, C C; Weng, Z L; Whitman, K; Wienkenhöver, J; Willenbrock, M; Wu, H; Wu, X; Xia, X; Xiong, R Q; Xu, W; Yan, Q; Yang, J; Yang, M; Yang, Y; Yi, H; Yu, Y J; Yu, Z Q; Zeissler, S; Zhang, C; Zhang, J; Zhang, J H; Zhang, S D; Zhang, S W; Zhang, Z; Zheng, Z M; Zhu, Z Q; Zhuang, H L; Zhukov, V; Zichichi, A; Zimmermann, N; Zuccon, P
2016-08-26
A precision measurement by AMS of the antiproton flux and the antiproton-to-proton flux ratio in primary cosmic rays in the absolute rigidity range from 1 to 450 GV is presented based on 3.49×10^{5} antiproton events and 2.42×10^{9} proton events. The fluxes and flux ratios of charged elementary particles in cosmic rays are also presented. In the absolute rigidity range ∼60 to ∼500 GV, the antiproton p[over ¯], proton p, and positron e^{+} fluxes are found to have nearly identical rigidity dependence and the electron e^{-} flux exhibits a different rigidity dependence. Below 60 GV, the (p[over ¯]/p), (p[over ¯]/e^{+}), and (p/e^{+}) flux ratios each reaches a maximum. From ∼60 to ∼500 GV, the (p[over ¯]/p), (p[over ¯]/e^{+}), and (p/e^{+}) flux ratios show no rigidity dependence. These are new observations of the properties of elementary particles in the cosmos.
Hubert, G; Regis, D; Cheminet, A; Gatti, M; Lacoste, V
2014-10-01
Particles originating from primary cosmic radiation, which hit the Earth's atmosphere give rise to a complex field of secondary particles. These particles include neutrons, protons, muons, pions, etc. Since the 1980s it has been known that terrestrial cosmic rays can penetrate the natural shielding of buildings, equipment and circuit package and induce soft errors in integrated circuits. Recently, research has shown that commercial static random access memories are now so small and sufficiently sensitive that single event upsets (SEUs) may be induced from the electronic stopping of a proton. With continued advancements in process size, this downward trend in sensitivity is expected to continue. Then, muon soft errors have been predicted for nano-electronics. This paper describes the effects in the specific cases such as neutron-, proton- and muon-induced SEU observed in complementary metal-oxide semiconductor. The results will allow investigating the technology node sensitivity along the scaling trend. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
NASA Astrophysics Data System (ADS)
Aguilar, M.; Ali Cavasonza, L.; Alpat, B.; Ambrosi, G.; Arruda, L.; Attig, N.; Aupetit, S.; Azzarello, P.; Bachlechner, A.; Barao, F.; Barrau, A.; Barrin, L.; Bartoloni, A.; Basara, L.; Başeǧmez-du Pree, S.; Battarbee, M.; Battiston, R.; Bazo, J.; Becker, U.; Behlmann, M.; Beischer, B.; Berdugo, J.; Bertucci, B.; Bindi, V.; Boella, G.; de Boer, W.; Bollweg, K.; Bonnivard, V.; Borgia, B.; Boschini, M. J.; Bourquin, M.; Bueno, E. F.; Burger, J.; Cadoux, F.; Cai, X. D.; Capell, M.; Caroff, S.; Casaus, J.; Castellini, G.; Cernuda, I.; Cervelli, F.; Chae, M. J.; Chang, Y. H.; Chen, A. I.; Chen, G. M.; Chen, H. S.; Cheng, L.; Chou, H. Y.; Choumilov, E.; Choutko, V.; Chung, C. H.; Clark, C.; Clavero, R.; Coignet, G.; Consolandi, C.; Contin, A.; Corti, C.; Coste, B.; Creus, W.; Crispoltoni, M.; Cui, Z.; Dai, Y. M.; Delgado, C.; Della Torre, S.; Demirköz, M. B.; Derome, L.; Di Falco, S.; Dimiccoli, F.; Díaz, C.; von Doetinchem, P.; Dong, F.; Donnini, F.; Duranti, M.; D'Urso, D.; Egorov, A.; Eline, A.; Eronen, T.; Feng, J.; Fiandrini, E.; Finch, E.; Fisher, P.; Formato, V.; Galaktionov, Y.; Gallucci, G.; García, B.; García-López, R. J.; Gargiulo, C.; Gast, H.; Gebauer, I.; Gervasi, M.; Ghelfi, A.; Giovacchini, F.; Goglov, P.; Gómez-Coral, D. M.; Gong, J.; Goy, C.; Grabski, V.; Grandi, D.; Graziani, M.; Guerri, I.; Guo, K. H.; Habiby, M.; Haino, S.; Han, K. C.; He, Z. H.; Heil, M.; Hoffman, J.; Hsieh, T. H.; Huang, H.; Huang, Z. C.; Huh, C.; Incagli, M.; Ionica, M.; Jang, W. Y.; Jinchi, H.; Kang, S. C.; Kanishev, K.; Kim, G. N.; Kim, K. S.; Kirn, Th.; Konak, C.; Kounina, O.; Kounine, A.; Koutsenko, V.; Krafczyk, M. S.; La Vacca, G.; Laudi, E.; Laurenti, G.; Lazzizzera, I.; Lebedev, A.; Lee, H. T.; Lee, S. C.; Leluc, C.; Li, H. S.; Li, J. Q.; Li, J. Q.; Li, Q.; Li, T. X.; Li, W.; Li, Z. H.; Li, Z. Y.; Lim, S.; Lin, C. H.; Lipari, P.; Lippert, T.; Liu, D.; Liu, Hu; Lu, S. Q.; Lu, Y. S.; Luebelsmeyer, K.; Luo, F.; Luo, J. Z.; Lv, S. S.; Majka, R.; Mañá, C.; Marín, J.; Martin, T.; Martínez, G.; Masi, N.; Maurin, D.; Menchaca-Rocha, A.; Meng, Q.; Mo, D. C.; Morescalchi, L.; Mott, P.; Nelson, T.; Ni, J. Q.; Nikonov, N.; Nozzoli, F.; Nunes, P.; Oliva, A.; Orcinha, M.; Palmonari, F.; Palomares, C.; Paniccia, M.; Pauluzzi, M.; Pensotti, S.; Pereira, R.; Picot-Clemente, N.; Pilo, F.; Pizzolotto, C.; Plyaskin, V.; Pohl, M.; Poireau, V.; Putze, A.; Quadrani, L.; Qi, X. M.; Qin, X.; Qu, Z. Y.; Räihä, T.; Rancoita, P. G.; Rapin, D.; Ricol, J. S.; Rodríguez, I.; Rosier-Lees, S.; Rozhkov, A.; Rozza, D.; Sagdeev, R.; Sandweiss, J.; Saouter, P.; Schael, S.; Schmidt, S. M.; Schulz von Dratzig, A.; Schwering, G.; Seo, E. S.; Shan, B. S.; Shi, J. Y.; Siedenburg, T.; Son, D.; Song, J. W.; Sun, W. H.; Tacconi, M.; Tang, X. W.; Tang, Z. C.; Tao, L.; Tescaro, D.; Ting, Samuel C. C.; Ting, S. M.; Tomassetti, N.; Torsti, J.; Türkoǧlu, C.; Urban, T.; Vagelli, V.; Valente, E.; Vannini, C.; Valtonen, E.; Vázquez Acosta, M.; Vecchi, M.; Velasco, M.; Vialle, J. P.; Vitale, V.; Vitillo, S.; Wang, L. Q.; Wang, N. H.; Wang, Q. L.; Wang, X.; Wang, X. Q.; Wang, Z. X.; Wei, C. C.; Weng, Z. L.; Whitman, K.; Wienkenhöver, J.; Willenbrock, M.; Wu, H.; Wu, X.; Xia, X.; Xiong, R. Q.; Xu, W.; Yan, Q.; Yang, J.; Yang, M.; Yang, Y.; Yi, H.; Yu, Y. J.; Yu, Z. Q.; Zeissler, S.; Zhang, C.; Zhang, J.; Zhang, J. H.; Zhang, S. D.; Zhang, S. W.; Zhang, Z.; Zheng, Z. M.; Zhu, Z. Q.; Zhuang, H. L.; Zhukov, V.; Zichichi, A.; Zimmermann, N.; Zuccon, P.; AMS Collaboration
2016-08-01
A precision measurement by AMS of the antiproton flux and the antiproton-to-proton flux ratio in primary cosmic rays in the absolute rigidity range from 1 to 450 GV is presented based on 3.49 ×1 05 antiproton events and 2.42 ×1 09 proton events. The fluxes and flux ratios of charged elementary particles in cosmic rays are also presented. In the absolute rigidity range ˜60 to ˜500 GV , the antiproton p ¯, proton p , and positron e+ fluxes are found to have nearly identical rigidity dependence and the electron e- flux exhibits a different rigidity dependence. Below 60 GV, the (p ¯/p ), (p ¯/e+), and (p /e+) flux ratios each reaches a maximum. From ˜60 to ˜500 GV , the (p ¯/p ), (p ¯/e+), and (p /e+) flux ratios show no rigidity dependence. These are new observations of the properties of elementary particles in the cosmos.
Haymaker, W; Zeman, W; Turnbill, C E; Clayton, R K; Bailey, O T; Samorajski, T; Vogel, F S; Lloyd, B; Cruty, M R; Benton, E V; Kraft, L M
1975-04-01
Tissue reactions were found around the monitor (dosimeter) assemblies that had been implanted beneath the scalp of the five pocket mice that flew on Apollo XVII. Mitosis in the dentate gyrus of the hippocampal formation was considerably reduced in comparison with that in control animals. Otherwise the brain tissue as well as the menings in the flight animals appeared unaltered. Since the animals were exposed primarily to high Z-high energy (HZE) cosmic ray particles at the lower end of the high LET spectrum, the lack of changes in the brain cannot be taken as evidence that the brain will suffer no damage from the heavier HZE particles on prolonged manned missions.
The mass composition of ultra-high energy cosmic rays with the Pierre Auger Observatory
NASA Astrophysics Data System (ADS)
Martraire, D.
2014-12-01
Ultra-high energy cosmic rays are the most energetic particles known in nature. The Pierre Auger Observatory was built to study these amazing particles to determine their origin. The study of their mass composition can help to constrain the models concerning their origins and their production mechanisms in the astrophysical sources. To this aim, several methods have been developed to infer the composition using the Auger surface detector array data. The main difficulty is to isolate the muonic component in the signal measured by the surface detector. We present the results of the composition parameters derived from the ground level component and compare them to the predictions for different nuclear masses of the primary particles and hadronic interaction models.
A particle astrophysics magnet facility: ASTROMAG
NASA Technical Reports Server (NTRS)
Ormes, Jonathan F. (Editor); Israel, Martin H. (Editor); Mewaldt, Richard A. (Editor); Wiedenbeck, Mark E. (Editor)
1988-01-01
The primary scientific objectives of ASTROMAG are to: examine cosmological models by searching for antimatter and dark matter candidates; study the origin and evolution of matter in the galaxy by direct sampling of galactic matter; and study the origin and acceleration of the relativistic particle plasma in the galaxy and its effects on the dynamics and evolution of the galaxy. These general scientific objectives will be met by ASTROMAG with particle detection instruments designed to make the following observations: search, for anti-nuclei of helium and heavier element; measure the spectra of anti-protons and positrons; measure the isotopic composition of cosmic ray nuclei at energies of several GeV/amu; and measure the energy spectra of cosmic ray nuclei to very high energies.
Observations of hydrogen and helium isotopes in solar cosmic rays. Ph.D. Thesis
NASA Technical Reports Server (NTRS)
Hurford, G. J.
1974-01-01
The isotopic composition of hydrogen and helium in solar cosmic rays provides a means of studying solar flare particle acceleration mechanisms since the enhanced relative abundance of rare isotopes, such as H-2, H-3, and He-3, is due to their production by inelastic nuclear collisions in the solar atmosphere during the flare. Electron isotope spectrometer on an IMP spacecraft was used to measure this isotopic composition. The response of the dE/dx-E particle telescope is discussed, and alpha particle channeling in thin detectors is identified as an important background source affecting measurement of low values of (He-3/He-4). The flare-averaged results obtained for the period October, 1972 November, 1973 are given.
Anomalies in cosmic rays: New particles versus charm?
NASA Technical Reports Server (NTRS)
Balayan, G. L.; Khodjamirian, A. Y.; Oganessian, A. G.
1985-01-01
For a long time two anomalies are observed in cosmic rays at energies E approx. = 100 TeV: (1) the generation of long-flying cascades in the hadron calorimeter (the so-called Tien-Shan effect) and; (2) the enhancement of direct muon yield as compared with the accelerator energy region. The aim is to discuss the possibility that both anomalies have common origins arising from production and decays of the same particles. the main conclusions are the following: (1) direct muons cannot be generated by any new particles with mass exceeding 10+20 GeV; and (2) if both effects are originated from the charmed hadrons, then the needed charm hadroproduction cross section is unexpectedly large as compared with the quark-gluon model predictions.
Cosmic Dust and the Earth's Atmosphere (Vilhelm Bjerknes Medal Lecture)
NASA Astrophysics Data System (ADS)
Plane, John M. C.
2017-04-01
Cosmic dust particles are produced in the solar system from the sublimation of comets as they orbit close to the sun, and also from collisions between asteroids in the belt between Mars and Jupiter. Dust particles enter the atmosphere at hyperthermal velocities (11 - 72 km s-1), and ablate at heights between 80 and 120 km in the mesosphere/lower thermosphere (MLT). The resulting metallic vapours (Fe, Mg, Si and Na etc.) then oxidize and recondense to form nm-size particles, termed "meteoric smoke particles (MSPs)". MSPs are too small to sediment downwards and so are transported by the general circulation of the atmosphere, taking roughly 4 years to reach the surface. Smoke particles play a potentially important role as condensation nuclei of noctilucent ice clouds in the mesosphere, and polar stratospheric clouds in the lower stratosphere, where they also facilitate freezing of the clouds. There are also potential implications for climate, as the input of bio-available cosmic Fe in the Southern Ocean can increase biological productivity and stimulate CO2 drawdown from the atmosphere. However, current estimates of the magnitude of the cosmic dust mass input rate into the Earth's atmosphere range from 2 to over 200 tonnes per day, depending on whether the measurements are made in space, in the middle atmosphere, or in polar ice cores. This nearly 2 order-of-magnitude discrepancy indicates that there must be serious flaws in the interpretation of observations that have been used to make the estimates. Furthermore, given this degree of uncertainty, the significance of these potential atmospheric impacts remains speculative. In this lecture I will describe the results of a large study designed to determine the size of the cosmic dust input rate using a self-consistent treatment of cosmic dust from the outer solar system to the Earth's surface. An astronomical model which tracks the evolution of dust from various sources into the inner solar system was combined with a chemical ablation model to determine the rate of injection of metallic vapours into the atmosphere. Constraining these coupled models with lidar measurements of the vertical fluxes of Na and Fe in the MLT, and the rate of accretion of cosmic spherules at the South Pole, indicates that about 40 tonnes of dust enters the atmosphere each day, of which ˜18% ablates. The subsequent atmospheric chemistry of the ablated metallic vapours is then examined using the Whole Atmosphere Community Climate Model (WACCM), coupled with the aerosol microphysics model CARMA to treat the interplay of meteoric smoke particles with the stratospheric sulphate layer. While the optical extinction of meteoric smoke in the lower mesosphere, and of refractory material in polar stratospheric clouds is satisfactorily modelled, two problems remain. First, the injection rate of Na and Fe atoms is too large (by a factor between 5 and 10) for WACCM to replicate the observed metal atom layer densities in the MLT. It appears that vertical transport by eddy diffusion has to be significantly supplemented by chemical transport produced by unresolved (sub-grid) gravity waves (this process will significantly affect the transport of other species such as atomic O through the MLT). The second problem is that the rate of deposition of MSPs at polar latitudes is substantially underestimated by the model, indicating that there may be an efficient process for removing particles directly from the lower stratospheric winter polar vortex to the surface. Underpinning the model development are three novel experimental systems developed at Leeds: a Meteor Ablation Simulator, which measures the evaporation of metals from cosmic dust particles that are flash heated to over 2800 K; a Time-of-Flight mass spectrometer with laser photo-ionization which is used to study the reactions of neutral metallic compounds in the gas phase; and a flowing afterglow experiment to study the dissociative recombination of metallic ions with electrons.
Nineteenth International Cosmic Ray Conference. HE Sessions, Volume 6
NASA Technical Reports Server (NTRS)
Jones, F. C. (Compiler)
1985-01-01
Papers contributed to the 19th International Cosmic Ray Conference which address high energy interactions and related phenomena are compiled. Particular topic areas include cross sections; particle production; nuclei and nuclear matter; nucleus-nucleus collisions; gamma ray and hadron spectra; C-jets, a-jets, and super families; and emulsion chamber simulations.
NASA Astrophysics Data System (ADS)
Ivanenko, I. P.; Rapoport, I. D.; Shestoperov, V. Ya.
The supplementary information is given. The information covers earlier published primary data of the experiments on high-energy cosmic radiation investigation at the KOSMOS-1713 satellite with the SOKOL-2 equipment.
Biocore experiment. [Apollo 17 mission
NASA Technical Reports Server (NTRS)
Bailey, O. T.; Benton, E. V.; Cruty, M. R.; Harrison, G. A.; Haymaker, W.; Humason, G.; Leon, H. A.; Lindberg, R. L.; Look, B. C.; Lushbaugh, C. C.
1973-01-01
The Apollo 17 biological cosmic ray experiment to determine the effect of heavy cosmic ray particles on the brain and eyes is reported. The pocket mouse was selected as the biological specimen for the experiment. The radiation monitors, animal autopsy and animal processing are described, and the radiation effects on the scalp, retina, and viscera are analyzed.
Possible interaction between baryons and dark-matter particles revealed by the first stars
NASA Astrophysics Data System (ADS)
Barkana, Rennan
2018-03-01
The cosmic radio-frequency spectrum is expected to show a strong absorption signal corresponding to the 21-centimetre-wavelength transition of atomic hydrogen around redshift 20, which arises from Lyman-α radiation from some of the earliest stars. By observing this 21-centimetre signal—either its sky-averaged spectrum or maps of its fluctuations, obtained using radio interferometers—we can obtain information about cosmic dawn, the era when the first astrophysical sources of light were formed. The recent detection of the global 21-centimetre spectrum reveals a stronger absorption than the maximum predicted by existing models, at a confidence level of 3.8 standard deviations. Here we report that this absorption can be explained by the combination of radiation from the first stars and excess cooling of the cosmic gas induced by its interaction with dark matter. Our analysis indicates that the spatial fluctuations of the 21-centimetre signal at cosmic dawn could be an order of magnitude larger than previously expected and that the dark-matter particle is no heavier than several proton masses, well below the commonly predicted mass of weakly interacting massive particles. Our analysis also confirms that dark matter is highly non-relativistic and at least moderately cold, and primordial velocities predicted by models of warm dark matter are potentially detectable. These results indicate that 21-centimetre cosmology can be used as a dark-matter probe.
Observation of the thunderstorm-related ground cosmic ray flux variations by ARGO-YBJ
NASA Astrophysics Data System (ADS)
Bartoli, B.; Bernardini, P.; Bi, X. J.; Cao, Z.; Catalanotti, S.; Chen, S. Z.; Chen, T. L.; Cui, S. W.; Dai, B. Z.; D'Amone, A.; Danzengluobu; De Mitri, I.; D'Ettorre Piazzoli, B.; Di Girolamo, T.; Di Sciascio, G.; Feng, C. F.; Feng, Zhaoyang; Feng, Zhenyong; Gao, W.; Gou, Q. B.; Guo, Y. Q.; He, H. H.; Hu, Haibing; Hu, Hongbo; Iacovacci, M.; Iuppa, R.; Jia, H. Y.; Labaciren; Li, H. J.; Liu, C.; Liu, J.; Liu, M. Y.; Lu, H.; Ma, L. L.; Ma, X. H.; Mancarella, G.; Mari, S. M.; Marsella, G.; Mastroianni, S.; Montini, P.; Ning, C. C.; Perrone, L.; Pistilli, P.; Salvini, P.; Santonico, R.; Shen, P. R.; Sheng, X. D.; Shi, F.; Surdo, A.; Tan, Y. H.; Vallania, P.; Vernetto, S.; Vigorito, C.; Wang, H.; Wu, C. Y.; Wu, H. R.; Xue, L.; Yang, Q. Y.; Yang, X. C.; Yao, Z. G.; Yuan, A. F.; Zha, M.; Zhang, H. M.; Zhang, L.; Zhang, X. Y.; Zhang, Y.; Zhao, J.; Zhaxiciren; Zhaxisangzhu; Zhou, X. X.; Zhu, F. R.; Zhu, Q. Q.; D'Alessandro, F.; ARGO-YBJ Collaboration
2018-02-01
A correlation between the secondary cosmic ray flux and the near-earth electric field intensity, measured during thunderstorms, has been found by analyzing the data of the ARGO-YBJ experiment, a full coverage air shower array located at the Yangbajing Cosmic Ray Laboratory (4300 m a. s. l., Tibet, China). The counting rates of showers with different particle multiplicities (m =1 , 2, 3, and ≥4 ) have been found to be strongly dependent upon the intensity and polarity of the electric field measured during the course of 15 thunderstorms. In negative electric fields (i.e., accelerating negative charges downwards), the counting rates increase with increasing electric field strength. In positive fields, the rates decrease with field intensity until a certain value of the field EFmin (whose value depends on the event multiplicity), above which the rates begin increasing. By using Monte Carlo simulations, we found that this peculiar behavior can be well described by the presence of an electric field in a layer of thickness of a few hundred meters in the atmosphere above the detector, which accelerates/decelerates the secondary shower particles of opposite charge, modifying the number of particles with energy exceeding the detector threshold. These results, for the first time to our knowledge, give a consistent explanation for the origin of the variation of the electron/positron flux observed for decades by high altitude cosmic ray detectors during thunderstorms.
Possible interaction between baryons and dark-matter particles revealed by the first stars.
Barkana, Rennan
2018-02-28
The cosmic radio-frequency spectrum is expected to show a strong absorption signal corresponding to the 21-centimetre-wavelength transition of atomic hydrogen around redshift 20, which arises from Lyman-α radiation from some of the earliest stars. By observing this 21-centimetre signal-either its sky-averaged spectrum or maps of its fluctuations, obtained using radio interferometers-we can obtain information about cosmic dawn, the era when the first astrophysical sources of light were formed. The recent detection of the global 21-centimetre spectrum reveals a stronger absorption than the maximum predicted by existing models, at a confidence level of 3.8 standard deviations. Here we report that this absorption can be explained by the combination of radiation from the first stars and excess cooling of the cosmic gas induced by its interaction with dark matter. Our analysis indicates that the spatial fluctuations of the 21-centimetre signal at cosmic dawn could be an order of magnitude larger than previously expected and that the dark-matter particle is no heavier than several proton masses, well below the commonly predicted mass of weakly interacting massive particles. Our analysis also confirms that dark matter is highly non-relativistic and at least moderately cold, and primordial velocities predicted by models of warm dark matter are potentially detectable. These results indicate that 21-centimetre cosmology can be used as a dark-matter probe.
Radio detection of high-energy cosmic rays with the Auger Engineering Radio Array
NASA Astrophysics Data System (ADS)
Schröder, Frank G.; Pierre Auger Collaboration
2016-07-01
The Auger Engineering Radio Array (AERA) is an enhancement of the Pierre Auger Observatory in Argentina. Covering about 17km2, AERA is the world-largest antenna array for cosmic-ray observation. It consists of more than 150 antenna stations detecting the radio signal emitted by air showers, i.e., cascades of secondary particles caused by primary cosmic rays hitting the atmosphere. At the beginning, technical goals had been in focus: first of all, the successful demonstration that a large-scale antenna array consisting of autonomous stations is feasible. Moreover, techniques for calibration of the antennas and time calibration of the array have been developed, as well as special software for the data analysis. Meanwhile physics goals come into focus. At the Pierre Auger Observatory air showers are simultaneously detected by several detector systems, in particular water-Cherenkov detectors at the surface, underground muon detectors, and fluorescence telescopes, which enables cross-calibration of different detection techniques. For the direction and energy of air showers, the precision achieved by AERA is already competitive; for the type of primary particle, several methods are tested and optimized. By combining AERA with the particle detectors we aim for a better understanding of cosmic rays in the energy range from approximately 0.3 to 10 EeV, i.e., significantly higher energies than preceding radio arrays.
Measurements of the dose due to cosmic rays in aircraft
NASA Astrophysics Data System (ADS)
Vuković, B.; Lisjak, I.; Radolić, V.; Vekić, B.; Planinić, J.
2006-06-01
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.
Observations of High Energy Cosmic Ray Electrons by the ATIC Balloon Experiment
NASA Technical Reports Server (NTRS)
Guzik, T. G.; Chang, J.; Adams, J. H., Jr.; Ahn, H. S.; Bashindzhagyan, G. L.; Christl, M.; Isbert, J.; Kim, K. C.; Kuznetsov, E. N.; Panasyuk, M. I.;
2009-01-01
Recently the Advanced Thin Ionization Calorimeter (ATIC) balloon experiment reported observations of high energy cosmic ray electrons over the energy range 300 to 800 GeV, indicating a feature or "bump" in the otherwise smoothly decreasing energy spectrum. The severe energy losses that occur as these high energy particles traverse the galaxy render the cosmic ray electron spectrum sensitive to local (a few kiloparsecs) sources and hence very interesting. The ATIC results are the first time that such a cosmic ray spectrum anomaly has been observed at high energy. Potential sources of this electron excess include pulsars, microquasars, supernovae remnants as well as the annihilation of exotic dark matter candidate particles. ATIC has had three successful high altitude flights over the continent of Antarctica 2000-2001, 2002-2003 and 2007-2008. Only results from the first two flights have been reported so far. During this talk we will discuss the ATIC experiment, the electron observations (including preliminary results from the most recent ATIC flight), examine the merits of the various source models and compare the ATIC observations with other recent measurements.
The Cosmic Ray Electron Excess
NASA Technical Reports Server (NTRS)
Chang, J.; Adams, J. H.; Ahn, H. S.; Bashindzhagyan, G. L.; Christl, M.; Ganel, O.; Guzik, T. G.; Isbert, J.; Kim, K. C.; Kuznetsov, E. N.;
2008-01-01
This slide presentation reviews the possible sources for the apparent excess of Cosmic Ray Electrons. The presentation reviews the Advanced Thin Ionization Calorimeter (ATIC) instrument, the various parts, how cosmic ray electrons are measured, and shows graphs that review the results of the ATIC instrument measurement. A review of Cosmic Ray Electrons models is explored, along with the source candidates. Scenarios for the excess are reviewed: Supernova remnants (SNR) Pulsar Wind nebulae, or Microquasars. Each of these has some problem that mitigates the argument. The last possibility discussed is Dark Matter. The Anti-Matter Exploration and Light-nuclei Astrophysics (PAMELA) mission is to search for evidence of annihilations of dark matter particles, to search for anti-nuclei, to test cosmic-ray propagation models, and to measure electron and positron spectra. There are slides explaining the results of Pamela and how to compare these with those of the ATIC experiment. Dark matter annihilation is then reviewed, which represent two types of dark matter: Neutralinos, and kaluza-Kline (KK) particles, which are next explained. The future astrophysical measurements, those from GLAST LAT, the Alpha Magnetic Spectrometer (AMS), and HEPCAT are reviewed, in light of assisting in finding an explanation for the observed excess. Also the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) could help by revealing if there are extra dimensions.
High-energy cosmic rays and the Greisen-Zatsepin-Kuz'min effect.
Watson, A A
2014-03-01
Although cosmic rays were discovered over 100 years ago their origin remains uncertain. They have an energy spectrum that extends from ∼1 GeV to beyond 10(20) eV, where the rate is less than 1 particle per km(2) per century. Shortly after the discovery of the cosmic microwave background in 1965, it was pointed out that the spectrum of cosmic rays should steepen fairly abruptly above about 4 × 10(19) eV, provided the sources are distributed uniformly throughout the Universe. This prediction, by Greisen and by Zatsepin and Kuz'min, has become known as the GZK effect and in this article I discuss the current position with regard to experimental data on the energy spectrum of the highest cosmic-ray energies that have been accumulated in a search that has lasted nearly 50 years. Although there is now little doubt that a suppression of the spectrum exists near the energy predicted, it is by no means certain that this is a manifestation of the GZK effect as it might be that this energy is also close to the maximum to which sources can accelerate particles, with the highest energy beam containing a large fraction of nuclei heavier than protons. The way forward is briefly mentioned.
Can EMMA solve the puzzle of the knee?
NASA Astrophysics Data System (ADS)
Kalliokoski, T.; Bezrukov, L.; Enqvist, T.; Fynbo, H.; Inzhechik, L.; Jones, P.; Joutsenvaara, J.; Karjalainen, J.; Kuusiniemi, P.; Loo, K.; Lubsandorzhiev, B.; Petkov, V.; Räihä, T.; Sarkamo, J.; Slupecki, M.; Trzaska, W. H.; Virkajärvi, A.
2011-04-01
The knee is a change in the slope of the cosmic ray spectrum at approximate energy of 3 PeV. There are multiple competing models for the knee giving conflicting predictions about this change for different masses of the primary particle. Accurate mass measurements of cosmic rays spectra around 3 PeV would be able to exclude some of these models. Cosmic-ray experiment EMMA uses a new method for studying the composition of cosmic rays at the knee area. It is able to determine the multiplicity, the lateral distribution, and the arrival direction of incoming muons produced early in the shower evolution on an event-by-event basis and deduce from these measurements the mass and the energy of the primary particle. EMMA is situated at the depth of 75 m in the Pyhäsalmi mine, Finland. This rock overburden, which corresponds to 210 m of water equivalent, gives EMMA a cut-off energy of 50 GeV for vertical muons. Since the simulations using different air-shower models give similar predictions for the lateral distribution of these high energy muons, we are confident that EMMA should yield a reliable and an air-shower model independent data on the composition of cosmic rays around the knee region.
Measurements of the Charged and Neutral Particle Spectra on the Martian Surface with MSL/RAD
NASA Astrophysics Data System (ADS)
Koehler, Jan
The Radiation Assessment Detector (RAD) onboard Mars Science Laboratory’s rover Curiosity is the first ever instrument to measure the energetic particle radiation environment on the surface of Mars. Charged particles are a major component of this environment, both galactic cosmic rays propagating to the Martian surface and secondary particles created by interactions of these cosmic rays with the atoms of the Martian atmosphere and soil. Another important factor for determining the biological impact of the Martian surface radiation is the specific contribution of neutrons, which possess a high biological effectiveness. In contrast to charged particles, neutrons and gamma rays are generally only measured indirectly. Their measurement is the result of a complex convolution of the incident particle spectrum with the measurement process. We apply an inversion method to calculate the gamma/neutron spectra from the RAD neutral particle measurements. Here we show first surface measurements of the Martian particle spectra and compare them to theoretical predictions. Measuring the Martian particle spectra is an essential step for determining the mutagenic influences to past or present life at or beneath the Martian surface as well as the radiation hazard for future human exploration, including the shielding design of a potential habitat.
Research in particles and fields
NASA Technical Reports Server (NTRS)
Vogt, R. E.; Buffington, A.; Davis, L., Jr.; Stone, E. C.
1980-01-01
The astrophysical aspects of cosmic and gamma rays and the radiation environment of the Earth and other planets investigated by means of energetic particle detector systems flown on spacecraft and balloons are discussed. The theory of particles and fields in space is also addressed with particular emphasis on models of Saturn's magnetic field.
The Vainshtein mechanism in the cosmic web
DOE Office of Scientific and Technical Information (OSTI.GOV)
Falck, Bridget; Koyama, Kazuya; Zhao, Gong-bo
We investigate the dependence of the Vainshtein screening mechanism on the cosmic web morphology of both dark matter particles and halos as determined by ORIGAMI. Unlike chameleon and symmetron screening, which come into effect in regions of high density, Vainshtein screening instead depends on the dimensionality of the system, and screened bodies can still feel external fields. ORIGAMI is well-suited to this problem because it defines morphologies according to the dimensionality of the collapsing structure and does not depend on a smoothing scale or density threshold parameter. We find that halo particles are screened while filament, wall, and void particlesmore » are unscreened, and this is independent of the particle density. However, after separating halos according to their large scale cosmic web environment, we find no difference in the screening properties of halos in filaments versus halos in clusters. We find that the fifth force enhancement of dark matter particles in halos is greatest well outside the virial radius. We confirm the theoretical expectation that even if the internal field is suppressed by the Vainshtein mechanism, the object still feels the fifth force generated by the external fields, by measuring peculiar velocities and velocity dispersions of halos. Finally, we investigate the morphology and gravity model dependence of halo spins, concentrations, and shapes.« less
The charged particle veto system of the cosmic ray electron synchrotron telescope
NASA Astrophysics Data System (ADS)
Geske, Matthew T.
The Cosmic Ray Electron Synchrotron Telescope is a balloon-borne detector designed to measure cosmic electrons at energies from 2 to 50 TeV. CREST completed a successful 10-day Antarctic flight which launched on December 25, 2011. CREST utilizes a novel detection method, searching for the synchrotron radiation emitted by the interaction of TeV-energy electrons with the geomagnetic field. The main detector component for CREST is a 32 x 32 square array of BaF 2 crystal detectors coupled to photomultiplier tubes, with an inter-crystal spacing of 7.5 cm. This document describes the design, construction and flight of the CREST experiment. A special focus is put upon the charged particle veto system, and its use in the analysis of the CREST results. The veto system, consisting of a series of 27 large slabs of organic plastic scintillator read out through photomultiplier tubes, is designed as a passive mechanism for rejecting charged particle events that could contaminate the X-ray signal from synchrotron radiation. The CREST veto system has 99.15% geometric coverage, with individual detector components exhibiting a mean detection efficiency of 99.7%. In whole, the veto system provides a charged particle rejection factor of better than 7 x 103.
Testing a Prototype for a New Cosmic Ray Particle Detector at the South Pole
NASA Astrophysics Data System (ADS)
Howell, R.; Rimsa, E.; Tharp, T.; Andeen, K.
2017-01-01
Cosmic ray research has grown rapidly in the past century, often using vacuum photomultiplier tubes (PMTs) to analyze the light produced by high-energy particles passing through scintillating material. Silicon photomultipliers (SiPMs) are now being recognized as a more efficient alternative to PMTs. Different types of photon events have been characterized using a SensL brand SiPM in combination with a QuarkNet Data Acquisition board. The goal of this study is to test the viability of the SiPM for a new generation surface detector at the South Pole.
NASA Technical Reports Server (NTRS)
Takahashi, Y.
1985-01-01
Observational data on anomalous cosmic-ray interaction events are compiled, classified, and briefly characterized. The events are divided into three groups: those confirmed by later observation or experiment, those shown to be the result of observational or analytical error, and those still unexplained. Among the phenomena in the latter group are magnetic-monopole candidates, fractionally charged particles, massive stable particles, anomalons, proton-decay and neutron-oscillation candidates, muon bundles, narrow showers, anomalous photons, fanlike phenomena, quark-gluon-plasma candidates, and anomalous long-range delta rays.
NASA Astrophysics Data System (ADS)
2011-01-01
Particle Physics: ATLAS unveils mural at CERN Prize: Corti Trust invites essay entries Astrophysics: CERN holds cosmic-ray conference Researchers in Residence: Lord Winston returns to school Music: ATLAS scientists record physics music Conference: Champagne flows at Reims event Competition: Students triumph at physics olympiad Teaching: Physics proves popular in Japanese schools Forthcoming Events
NASA Technical Reports Server (NTRS)
Buecker, H.; Facius, R.; Hildebrand, D.; Horneck, G.; Reitz, G.; Scheidemann, U.; Schaefer, M.; Thomas, C.; Toth, B.; Kranz, A. R.
1976-01-01
The Biostack III experiment onboard the Apollo spacecraft during the Apollo Soyuz Test Project complemented the Biostack I and II experiments of the Apollo 16 and 17 missions. The objectives of these experiments were to study the biological effects of individual heavy cosmic particles of high energy loss (HZE) not available on earth, to study the influence of additional space flight factors, to obtain knowledge on the mechanism by which HZE particles damage biological materials, to get information on the spectrum of charge and energy of the cosmic ions in the spacecraft, and to estimate the radiation hazards to man in space.
Karam, P Andrew
2003-03-01
Four billion years ago, sea-level UV exposure was more than 400 times as intense as today, the dose from solar cosmic rays was five times present levels, and galactic cosmic rays accounted for only about 10% their current contribution to sea-level radiation doses. Exposure to cosmic radiation accounts for about 10% of natural background radiation exposure today and includes dose from galactic cosmic rays and solar charged particles. There is little exposure to ionizing wavelengths of UV due to absorption by ozone. The sun has evolved significantly over its life; in the past there were higher levels of particulate radiation and lower UV emissions from the sun, and a stronger solar wind reduced radiation dose in the inner solar system from galactic cosmic rays. Finally, since the early atmosphere contained little to no oxygen, surface levels of UV radiation were far higher in the past.
Cosmic ray spectrum, composition, and anisotropy measured with IceCube
NASA Astrophysics Data System (ADS)
Tamburro, Alessio
2014-04-01
Analysis of cosmic ray surface data collected with the IceTop array of Cherenkov detectors at the South Pole provides an accurate measurement of the cosmic ray spectrum and its features in the "knee" region up to energies of about 1 EeV. IceTop is part of the IceCube Observatory that includes a deep-ice cubic kilometer detector that registers signals of penetrating muons and other particles. Surface and in-ice signals detected in coincidence provide clear insights into the nuclear composition of cosmic rays. IceCube already measured an increase of the average primary mass as a function of energy. We present preliminary results on both IceTop-only and coincident events analysis. Furthermore, we review the recent measurement of the cosmic ray anisotropy with IceCube.
Cosmic Rays - A Word-Wide Student Laboratory
NASA Astrophysics Data System (ADS)
Adams, Mark
2017-01-01
The QuarkNet program has distributed hundreds of cosmic ray detectors for use in high schools and research facilities throughout the world over the last decade. Data collected by those students has been uploaded to a central server where web-based analysis tools enable users to characterize and to analyze everyone's cosmic ray data. Since muons rain down on everyone in the world, all students can participate in this free, high energy particle environment. Through self-directed inquiry students have designed their own experiments: exploring cosmic ray rates and air shower structure; and using muons to measure their speed, time dilation, lifetime, and affects on biological systems. We also plan to expand our annual International Muon Week project to create a large student-led collaboration where similar cosmic ray measurements are performed simultaneously throughout the world.
Cosmic muon induced EM showers in NO$$\
Yadav, Nitin; Duyang, Hongyue; Shanahan, Peter; ...
2016-11-15
Here, the NuMI Off-Axis v e Appearance (NOvA) experiment is a ne appearance neutrino oscillation experiment at Fermilab. It identifies the ne signal from the electromagnetic (EM) showers induced by the electrons in the final state of neutrino interactions. Cosmic muon induced EM showers, dominated by bremsstrahlung, are abundant in NOvA far detector. We use the Cosmic Muon- Removal technique to get pure EM shower sample from bremsstrahlung muons in data. We also use Cosmic muon decay in flight EM showers which are highly pure EM showers.The large Cosmic-EM sample can be used, as data driven method, to characterize themore » EM shower signature and provides valuable checks of the simulation, reconstruction, particle identification algorithm, and calibration across the NOvA detector.« less
Cosmic muon induced EM showers in NO$$\
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yadav, Nitin; Duyang, Hongyue; Shanahan, Peter
Here, the NuMI Off-Axis v e Appearance (NOvA) experiment is a ne appearance neutrino oscillation experiment at Fermilab. It identifies the ne signal from the electromagnetic (EM) showers induced by the electrons in the final state of neutrino interactions. Cosmic muon induced EM showers, dominated by bremsstrahlung, are abundant in NOvA far detector. We use the Cosmic Muon- Removal technique to get pure EM shower sample from bremsstrahlung muons in data. We also use Cosmic muon decay in flight EM showers which are highly pure EM showers.The large Cosmic-EM sample can be used, as data driven method, to characterize themore » EM shower signature and provides valuable checks of the simulation, reconstruction, particle identification algorithm, and calibration across the NOvA detector.« less
Cosmic archaeology with gravitational waves from cosmic strings
NASA Astrophysics Data System (ADS)
Cui, Yanou; Lewicki, Marek; Morrissey, David E.; Wells, James D.
2018-06-01
Cosmic strings are generic cosmological predictions of many extensions of the standard model of particle physics, such as a U (1 )' symmetry-breaking phase transition in the early Universe or remnants of superstring theory. Unlike other topological defects, cosmic strings can reach a scaling regime that maintains a small fixed fraction of the total energy density of the Universe from a very early epoch until today. If present, they will oscillate and generate gravitational waves with a frequency spectrum that imprints the dominant sources of total cosmic energy density throughout the history of the Universe. We demonstrate that current and future gravitational wave detectors, such as LIGO and LISA, could be capable of measuring the frequency spectrum of gravitational waves from cosmic strings and discerning the energy composition of the Universe at times well before primordial nucleosynthesis and the cosmic microwave background where standard cosmology has yet to be tested. This work establishes a benchmark case that gravitational waves may provide an unprecedented, powerful tool for probing the evolutionary history of the very early Universe.
NASA Technical Reports Server (NTRS)
Marshall, F. E.
1977-01-01
The anisotropy of 1.3 to 2.3 MeV protons in interplanetary space was measured using the Caltech electron/isotope spectrometer aboard IMP-7 for 317 6 hour periods from 72/273 to 74/2. Periods dominated by prompt solar particle events are not included. The convective and diffusive anisotropies were determined from the observed anisotropy using concurrent solar wind speed measurements and observed energy spectra. The diffusive flow of particles was found to be typically toward the sun, indicating a positive radial gradient in the particle density. This anisotropy was inconsistent with previously proposed sources of low energy proton increases seen at 1 AU which involve continual solar acceleration. The typical properties of this new component of low-energy cosmic rays were determined for this period which is near solar minimum.
A Novel Cosmic Ray Tagger System for Liquid Argon TPC Neutrino Detectors
Auger, Martin; Del Tutto, Marco; Ereditato, Antonio; ...
2017-02-22
The Fermilab Short Baseline Neutrino (SBN) program aims to observe and reconstruct thousands of neutrino-argon interactions with its three detectors (SBND, MicroBooNE and ICARUS-T600), using their hundred of tonnes Liquid Argon Time Projection Chambers to perform a rich physics analysis program, in particular focused in the search for sterile neutrinos. Given the relatively shallow depth of the detectors, the continuos flux of cosmic ray particles which crossing their volumes introduces a constant background which can be falsely identified as part of the event of interest. Here in this paper we present the Cosmic Ray Tagger (CRT) system, a novel techniquemore » to tag and identify these crossing particles using scintillation modules which measure their time and coordinates relative to events internal to the neutrino detector, mitigating therefore their effect in the event tracking reconstruction.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Anthonisen, Madeleine; Brandenberger, Robert; Laguë, Alex
Cosmic string loops contain cusps which decay by emitting bursts of particles. A significant fraction of the released energy is in the form of photons. These photons are injected non-thermally and can hence cause spectral distortions of the Cosmic Microwave Background (CMB). Under the assumption that cusps are robust against gravitational back-reaction, we compute the fractional energy density released as photons in the redshift interval where such non-thermal photon injection causes CMB spectral distortions. Whereas current constraints on such spectral distortions are not strong enough to constrain the string tension, future missions such as the PIXIE experiment will be ablemore » to provide limits which rule out a range of string tensions between G μ ∼ 10{sup −15} and G μ ∼ 10{sup −12}, thus ruling out particle physics models yielding these kind of intermediate-scale cosmic strings.« less
Anomalous Transport of High Energy Cosmic Rays in Galactic Superbubbles
NASA Technical Reports Server (NTRS)
Barghouty, Nasser F.
2014-01-01
High-energy cosmic rays may exhibit anomalous transport as they traverse and are accelerated by a collection of supernovae explosions in a galactic superbubble. Signatures of this anomalous transport can show up in the particles' evolution and their spectra. In a continuous-time-random- walk (CTRW) model assuming standard diffusive shock acceleration theory (DSA) for each shock encounter, and where the superbubble (an OB stars association) is idealized as a heterogeneous region of particle sources and sinks, acceleration and transport in the superbubble can be shown to be sub-diffusive. While the sub-diffusive transport can be attributed to the stochastic nature of the acceleration time according to DSA theory, the spectral break appears to be an artifact of transport in a finite medium. These CTRW simulations point to a new and intriguing phenomenon associated with the statistical nature of collective acceleration of high energy cosmic rays in galactic superbubbles.
Terrestrial effects of high energy cosmic rays
NASA Astrophysics Data System (ADS)
Atri, Dimitra
On geological timescales, the Earth is likely to be exposed to higher than the usual flux of high energy cosmic rays (HECRs) from astrophysical sources such as nearby supernovae, gamma ray bursts or by galactic shocks. These high-energy particles strike the Earth's atmosphere, initiating an extensive air shower. As the air shower propagates deeper, it ionizes the atmosphere by producing charged secondary particles and photons. Increased ionization leads to changes in atmospheric chemistry, resulting in ozone depletion. This increases the flux of solar UVB radiation at the surface, which is potentially harmful to living organisms. Increased ionization affects the global electrical circuit, which could enhance the low-altitude cloud formation rate. Secondary particles such as muons and thermal neutrons produced as a result of hadronic interactions of the primary cosmic rays with the atmosphere are able to reach the ground, enhancing the biological radiation dose. The muon flux dominates the radiation dose from cosmic rays causing damage to DNA and an increase in mutation rates and cancer, which can have serious biological implications for surface and sub-surface life. Using CORSIKA, we perform massive computer simulations and construct lookup tables for 10 GeV - 1 PeV primaries, which can be used to quantify these effects from enhanced cosmic ray exposure to any astrophysical source. These tables are freely available to the community and can be used for other studies. We use these tables to study the terrestrial implications of galactic shock generated by the infall of our galaxy toward the Virgo cluster. Increased radiation dose from muons could be a possible mechanism explaining the observed periodicity in biodiversity in paleobiology databases.
NASA Technical Reports Server (NTRS)
Lal, D.
1986-01-01
Temporal variations in cosmic ray intensity have been deduced from observations of products of interactions of cosmic ray particles in the Moon, meteorites, and the Earth. Of particular interest is a comparison between the information based on Earth and that based on other samples. Differences are expected at least due to: (1) differences in the extent of cosmic ray modulation, and (2) changes in the geomagnetic dipole field. Any information on the global changes in the terrestrial cosmic ray intensity is therefore of importance. In this paper a possible technique for detecting changes in cosmic ray intensity is presented. The method involves human intervention and is applicable for the past 10,000 yrs. Studies of changes over longer periods of time are possible if supplementary data on age and history of the sample are available using other methods. Also discussed are the possibilities of studying certain geophysical processes, e.g., erosion, weathering, tectonic events based on studies of certain cosmic ray-produced isotopes for the past several million years.
Heavy cosmic-ray exposure of Apollo astronauts.
Benton, E V; Henke, R P; Bailey, J V
1975-01-24
A comprehensive study of the heavy-particle cosmic-ray exposure received by the individual astronauts during the nine lunar Apollo missions reveals a significant variation in the exposure as a function of shielding and the phase of the solar cycle. The data are useful in planning for future long-range missions and in estimating the expected biological damage.
Cosmic ray acceleration in magnetic circumstellar bubbles
NASA Astrophysics Data System (ADS)
Zirakashvili, V. N.; Ptuskin, V. S.
2018-03-01
We consider the diffusive shock acceleration in interstellar bubbles created by powerful stellar winds of supernova progenitors. Under the moderate stellar wind magnetization the bubbles are filled by the strongly magnetized low density gas. It is shown that the maximum energy of particles accelerated in this environment can exceed the "knee" energy in the observable cosmic ray spectrum.
Description of alpha-nucleus interaction cross sections for cosmic ray shielding studies
NASA Technical Reports Server (NTRS)
Cucinotta, Francis A.; Townsend, Lawrence W.; Wilson, John W.
1993-01-01
Nuclear interactions of high-energy alpha particles with target nuclei important for cosmic ray studies are discussed. Models for elastic, quasi-elastic, and breakup reactions are presented and compared with experimental data. Energy-dependent interaction cross sections and secondary spectra are presented based on theoretical models and the limited experimental data base.
NASA Astrophysics Data System (ADS)
Kouznetsov, A.; Cully, C. M.; Knudsen, D. J.
2016-12-01
Changes in D-Region ionization caused by energetic particle precipitation are monitored by the Array for Broadband Observations of VLF/ELF Emissions (ABOVE) - a network of receivers deployed across Western Canada. The observed amplitudes and phases of subionospheric-propagating VLF signals from distant artificial transmitters depend sensitively on the free electron population created by precipitation of energetic charged particles. Those include both primary (electrons, protons and heavier ions) and secondary (cascades of ionized particles and electromagnetic radiation) components. We have designed and implemented a full-scale model to predict the received VLF signals based on first-principle charged particle transport calculations coupled to the Long Wavelength Propagation Capability (LWPC) software. Calculations of ionization rates and free electron densities are based on MCNP-6 (a general-purpose Monte Carlo N- Particle) software taking advantage of its capability of coupled neutron/photon/electron transport and novel library of cross-sections for low-energetic electron and photon interactions with matter. Cosmic ray calculations of background ionization are based on source spectra obtained both from PAMELA direct Cosmic Rays spectra measurements and based on the recently-implemented MCNP 6 galactic cosmic-ray source, scaled using our (Calgary) neutron monitor measurement results. Conversion from calculated fluxes (MCNP F4 tallies) to ionization rates for low-energy electrons are based on the total ionization cross-sections for oxygen and nitrogen molecules from the National Institute of Standard and Technology. We use our model to explore the complexity of the physical processes affecting VLF propagation.
NASA Technical Reports Server (NTRS)
Mashnik, S. G.; Gudima, K. K.; Sierk, A. J.; Moskalenko, I. V.
2002-01-01
Space radiation shield applications and studies of cosmic ray propagation in the Galaxy require reliable cross sections to calculate spectra of secondary particles and yields of the isotopes produced in nuclear reactions induced both by particles and nuclei at energies from threshold to hundreds of GeV per nucleon. Since the data often exist in a very limited energy range or sometimes not at all, the only way to obtain an estimate of the production cross sections is to use theoretical models and codes. Recently, we have developed improved versions of the Cascade-Exciton Model (CEM) of nuclear reactions: the codes CEM97 and CEM2k for description of particle-nucleus reactions at energies up to about 5 GeV. In addition, we have developed a LANL version of the Quark-Gluon String Model (LAQGSM) to describe reactions induced both by particles and nuclei at energies up to hundreds of GeVhucleon. We have tested and benchmarked the CEM and LAQGSM codes against a large variety of experimental data and have compared their results with predictions by other currently available models and codes. Our benchmarks show that CEM and LAQGSM codes have predictive powers no worse than other currently used codes and describe many reactions better than other codes; therefore both our codes can be used as reliable event-generators for space radiation shield and cosmic ray propagation applications. The CEM2k code is being incorporated into the transport code MCNPX (and several other transport codes), and we plan to incorporate LAQGSM into MCNPX in the near future. Here, we present the current status of the CEM2k and LAQGSM codes, and show results and applications to studies of cosmic ray propagation in the Galaxy.
Research in particles and fields
NASA Technical Reports Server (NTRS)
Stone, E. C.; Davis, L., Jr.; Mewaldt, R. A.; Prince, T. A.
1984-01-01
The astrophysical aspects of cosmic rays and gamma rays and of the electromagnetic field environment of the Earth and other planets are investigated. These investigations are carried out by means of energetic particle and photon detector systems flown on spacecraft and balloons.
Radiation portal monitor system and method
Morris, Christopher [Los Alamos, NM; Borozdin, Konstantin N [Los Alamos, NM; Green, J Andrew [Los Alamos, NM; Hogan, Gary E [Los Alamos, NM; Makela, Mark F [Los Alamos, NM; Priedhorsky, William C [Los Alamos, NM; Saunders, Alexander [Los Alamos, NM; Schultz, Larry J [Los Alamos, NM; Sossong, Michael J [Los Alamos, NM
2009-12-15
A portal monitoring system has a cosmic ray charged particle tracker with a plurality of drift cells. The drift cells, which can be for example aluminum drift tubes, can be arranged at least above and below a volume to be scanned to thereby track incoming and outgoing charged particles, such as cosmic ray muons, whilst also detecting gamma rays. The system can selectively detect devices or materials, such as iron, lead, gold and/or tungsten, occupying the volume from multiple scattering of the charged particles passing through the volume and can also detect any radioactive sources occupying the volume from gamma rays emitted therefrom. If necessary, the drift tubes can be sealed to eliminate the need for a gas handling system. The system can be employed to inspect occupied vehicles at border crossings for nuclear threat objects.
The charged particle radiation environment for AXAF
NASA Technical Reports Server (NTRS)
Joy, Marshall
1990-01-01
The Advanced X Ray Astrophysics Facility (AXAF) will be subjected to several sources of charged particle radiation during its 15-year orbital lifetime: geomagnetically-trapped electrons and protons, galactic cosmic ray particles, and solar flare events. These radiation levels are presented for the AXAF orbit for use in the design of the observatory's science instruments.
Neuronal stress following exposure to 56Fe particles and the effects of antioxidant-rich diets
USDA-ARS?s Scientific Manuscript database
Exposing young rats to particles of high energy and charge (HZE particles), a ground-based model for exposure to cosmic rays, enhances indices of oxidative stress and inflammation and disrupts the functioning of neuronal communication in critical regions of the brain. These changes in neuronal funct...
Neuronal stress following exposure to 56Fe particles and the effects of antioxidant-rich diets
USDA-ARS?s Scientific Manuscript database
Exposing young rats to particles of high energy and charge (HZE particles), a ground-based model for exposure to cosmic rays, enhances indices of oxidative stress and inflammation and disrupts the functioning of neuronal communication in critical regions of the brain, similar to those seen in aging....
Measurement of the energy of horizontal cosmic ray muons
NASA Astrophysics Data System (ADS)
Gettert, Michael
1993-03-01
An experiment in which the energy of cosmic ray muons is determined by measuring the electron positron pairs that they radiate off when passing through matter is described. The detector is a stack of lead converters interspersed with ionization chambers for particle detection. The chambers use as active medium the liquid tetra methyl silane (TMS). The radiated quanta initiate electromagnetic cascades in the lead and are recognized due to the characteristic shower development. The energy spectrum of horizontal muons is presented and from this the primary cosmic ray spectrum is deduced.
High Energy Astronomy Observatory (HEAO)
1970-01-01
This artist's concept depicts the third observatory, the High Energy Astronomy Observatory (HEAO)-3 in orbit. Designed and developed by TRW, Inc. under the direction of the Marshall Space Flight Center, the HEAO-3's mission was to survey and map the celestial sphere for gamma-ray flux and make detailed measurements of cosmic-ray particles. It carried three scientific experiments: a gamma-ray spectrometer, a cosmic-ray isotope experiment, and a heavy cosmic-ray nuclei experiment. The HEAO-3 was originally identified as HEAO-C but the designation was changed once the spacecraft achieved orbit.
Can we detect antimatter from other galaxies
NASA Technical Reports Server (NTRS)
Ahlen, S. P.; Price, P. B.; Salamon, M. H.; Tarle, G.
1982-01-01
A novel particle detection technique employing well established principles of high order quantum electrodynamics for searching for antimatter in cosmic rays is described, and shown to have both collecting power and resolution superior to conventional alternatives. By taking into account various estimates of the metagalactic cosmic-ray energy density, and the possible modulation of metagalactic cosmic rays by a galactic wind within the framework of the dynamical halo model, it is shown that the experiment proposed would be the first to be sensitive to the presence of extragalactic antimatter.
Evaluation of the cosmic-ray induced background in coded aperture high energy gamma-ray telescopes
NASA Technical Reports Server (NTRS)
Owens, Alan; Barbier, Loius M.; Frye, Glenn M.; Jenkins, Thomas L.
1991-01-01
While the application of coded-aperture techniques to high-energy gamma-ray astronomy offers potential arc-second angular resolution, concerns were raised about the level of secondary radiation produced in a thick high-z mask. A series of Monte-Carlo calculations are conducted to evaluate and quantify the cosmic-ray induced neutral particle background produced in a coded-aperture mask. It is shown that this component may be neglected, being at least a factor of 50 lower in intensity than the cosmic diffuse gamma-rays.
NASA Astrophysics Data System (ADS)
Bagheri, Zahra; Davoudifar, Pantea; Rastegarzadeh, Gohar; Shayan, Milad
2017-03-01
In this paper, we used CORSIKA code to understand the characteristics of cosmic ray induced showers at extremely high energy as a function of energy, detector distance to shower axis, number, and density of secondary charged particles and the nature particle producing the shower. Based on the standard properties of the atmosphere, lateral and longitudinal development of the shower for photons and electrons has been investigated. Fluorescent light has been collected by the detector for protons, helium, oxygen, silicon, calcium and iron primary cosmic rays in different energies. So we have obtained a number of electrons per unit area, distance to the shower axis, shape function of particles density, percentage of fluorescent light, lateral distribution of energy dissipated in the atmosphere and visual field angle of detector as well as size of the shower image. We have also shown that location of highest percentage of fluorescence light is directly proportional to atomic number of elements. Also we have shown when the distance from shower axis increases and the shape function of particles density decreases severely. At the first stages of development, shower axis distance from detector is high and visual field angle is small; then with shower moving toward the Earth, angle increases. Overall, in higher energies, the fluorescent light method has more efficiency. The paper provides standard calibration lines for high energy showers which can be used to determine the nature of the particles.
NASA Technical Reports Server (NTRS)
Postberg, F.; Sterken, V.; Achilles, C.; Allen, C.; Bastien, R. K.; Frank, D.; Sandford, S. A.; Zolensky, M. E.; Butterworth, A.; Gainesforth, Z.
2014-01-01
The NASA Stardust mission used silica aerogel slabs to slowly decelerate and capture impinging cosmic dust particles for return to Earth. During this process, impact tracks are generated along the trajectory of the particle into the aerogel. It is believed that the morphology and dimensions of these tracks, together with the state of captured grains at track termini, may be linked to the size, velocity, and density of the impacting cosmic dust grain. Here, we present the results of laboratory hypervelocity impact experiments, during which cosmic dust analog particles (diameters of between 0.2 and 0.4 lm), composed of olivine, orthopyroxene, or an organic polymer, were accelerated onto Stardust flight spare low-density (approximately 0.01 g/cu cm) silica aerogel. The impact velocities (3-21 km/s) were chosen to simulate the range of velocities expected during Stardust's interstellar dust (ISD) collection phases. Track lengths and widths, together with the success of particle capture, are analyzed as functions of impact velocity and particle composition, density, and size. Captured terminal particles from low-density organic projectiles become undetectable at lower velocities than those from similarly sized, denser mineral particles, which are still detectable (although substantially altered by the impact process) at 15 km/s. The survival of these terminal particles, together with the track dimensions obtained during low impact speed capture of small grains in the laboratory, indicates that two of the three best Stardust candidate extraterrestrial grains were actually captured at speeds much lower than predicted. Track length and diameters are, in general, more sensitive to impact velocities than previously expected, which makes tracks of particles with diameters of 0.4 lm and below hard to identify at low capture speeds (<10 km/s). Therefore, although captured intact, the majority of the interstellar dust grains returned to Earth by Stardust remain to be found.
Shock Wave Structure Mediated by Energetic Particles
NASA Astrophysics Data System (ADS)
Mostafavi, P.; Zank, G. P.; Webb, G. M.
2016-12-01
Energetic particles such as cosmic rays, Pick Up Ions (PUIs), and solar energetic particles can affect all facets of plasma physics and astrophysical plasma. Energetic particles play an especially significant role in the dissipative process at shocks and in determining their structure. The very interesting recent observations of shocks in the inner heliosphere found that many shocks appear to be significantly mediated by solar energetic particles which have a pressure that exceeds considerably both the thermal gas pressure and the magnetic field pressure. Energetic particles contribute an isotropic scalar pressure to the plasma system at the leading order, as well as introducing dissipation via a collisionless heat flux (diffusion) at the next order and a collisionless stress tensor (viscosity) at the second order. Cosmic-ray modified shocks were discussed by Axford et al. (1982), Drury (1983), and Webb (1983). Zank et al. (2014) investigated the incorporation of PUIs in the supersonic solar wind beyond 10AU, in the inner Heliosheath and in the Very Local Interstellar Medium. PUIs do not equilibrate collisionally with the background plasma in these regimes. In the absence of equilibration between plasma components, a separate coupled plasma description for the energetic particles is necessary. This model is used to investigate the structure of shock waves assuming that we can neglect the magnetic field. Specifically, we consider the dissipative role that both the energetic particle collisionless heat flux and viscosity play in determining the structure of collisionless shock waves. We show that the incorporation of both energetic particle collisionless heat flux and viscosity is sufficient to completely determine the structure of a shock. Moreover, shocks with three sub-shocks converge to the weak sub-shocks. This work differs from the investigation of Jokipii and Williams (1992) who restricted their attention to a cold thermal gas. For a cold thermal non-magnetized gas, all shocks are smoothed by cosmic ray diffusion and therefore viscosity is not an important process.
NASA Astrophysics Data System (ADS)
Grieder, P. K. F.
In 1912 Victor Franz Hess made the revolutionary discovery that ionizing radiation is incident upon the Earth from outer space. He showed with ground-based and balloon-borne detectors that the intensity of the radiation did not change significantly between day and night. Consequently, the sun could not be regarded as the sources of this radiation and the question of its origin remained unanswered. Today, almost one hundred years later the question of the origin of the cosmic radiation still remains a mystery. Hess' discovery has given an enormous impetus to large areas of science, in particular to physics, and has played a major role in the formation of our current understanding of universal evolution. For example, the development of new fields of research such as elementary particle physics, modern astrophysics and cosmology are direct consequences of this discovery. Over the years the field of cosmic ray research has evolved in various directions: Firstly, the field of particle physics that was initiated by the discovery of many so-called elementary particles in the cosmic radiation. There is a strong trend from the accelerator physics community to reenter the field of cosmic ray physics, now under the name of astroparticle physics. Secondly, an important branch of cosmic ray physics that has rapidly evolved in conjunction with space exploration concerns the low energy portion of the cosmic ray spectrum. Thirdly, the branch of research that is concerned with the origin, acceleration and propagation of the cosmic radiation represents a great challenge for astrophysics, astronomy and cosmology. Presently very popular fields of research have rapidly evolved, such as high-energy gamma ray and neutrino astronomy. In addition, high-energy neutrino astronomy may soon initiate as a likely spin-off neutrino tomography of the Earth and thus open a unique new branch of geophysical research of the interior of the Earth. Finally, of considerable interest are the biological and medical aspects of the cosmic radiation because of it ionizing character and the inevitable irradiation to which we are exposed. This book is a reference manual for researchers and students of cosmic ray physics and associated fields and phenomena. It is not intended to be a tutorial. However, the book contains an adequate amount of background materials that its content should be useful to a broad community of scientists and professionals. The present book contains chiefly a data collection in compact form that covers the cosmic radiation in the vicinity of the Earth, in the Earth's atmosphere, at sea level and underground. Included are predominantly experimental but also theoretical data. In addition the book contains related data, definitions and important relations. The aim of this book is to offer the reader in a single volume a readily available comprehensive set of data that will save him the need of frequent time consuming literature searches.
Diagenetically altered fossil micrometeorites suggest cosmic dust is common in the geological record
NASA Astrophysics Data System (ADS)
Suttle, Martin D.; Genge, Matthew J.
2017-10-01
We report the discovery of fossil micrometeorites from Late Cretaceous chalk. Seventy-six cosmic spherules were recovered from Coniacian (87 ± 1 Ma) sediments of the White Chalk Supergroup. Particles vary from pristine silicate and iron-type spherules to pseudomorphic spherules consisting of either single-phase recrystallized magnetite or Fe-silicide. Pristine spherules are readily identified as micrometeorites on the basis of their characteristic mineralogies, textures and compositions. Both magnetite and silicide spherules contain dendritic crystals and spherical morphologies, testifying to rapid crystallisation of high temperature iron-rich metallic and oxide liquids. These particles also contain spherical cavities, representing weathering and removal of metal beads and irregular cavities, representing vesicles formed by trapped gas during crystallization; both features commonly found among modern Antarctic Iron-type (I-type) cosmic spherules. On the basis of textural analysis, the magnetite and Fe-silicide spherules are shown to be I-type cosmic spherules that have experienced complete secondary replacement during diagenesis (fossilization). Our results demonstrate that micrometeorites, preserved in sedimentary rocks, are affected by a suite of complex diagenetic processes, which can result in disparate replacement minerals, even within the same sequence of sedimentary beds. As a result, the identification of fossil micrometeorites requires careful observation of particle textures and comparisons with modern Antarctic collections. Replaced micrometeorites imply that geochemical signatures the extraterrestrial dust are subject to diagenetic remobilisation that limits their stratigraphic resolution. However, this study demonstrates that fossil, pseudomorphic micrometeorites can be recognised and are likely common within the geological record.
NASA Technical Reports Server (NTRS)
Newkirk, G., Jr.; Asbridge, J.; Lockwood, J. A.; Garcia-Munoz, M.; Simpson, J. A.
1986-01-01
The role which empirical determinations of the latitudinal variation of cosmic rays with respect to the current sheet may have in illuminating the importance of the cross-field drift of particles in the large-scale heliospheric magnetic field is discussed. Using K coronameter observations and measured solar wind speeds, the latitudinal gradients have been determined with respect to the current sheet for cosmic rays in four rigidity ranges. Gradients vary between approximately -2 and -50 pct/AU. The rigidity dependence of the decrease of cosmic ray flux with distance from the current sheet lies between the -0.72 to -0.86 power of the rigidity, with the exact dependence being determined by the definition used for the median rigidity of each monitor.
Cosmic-ray record in solar system matter
NASA Technical Reports Server (NTRS)
Reedy, R. C.; Arnold, J. R.; Lal, D.
1983-01-01
The interaction of galactic cosmic rays (GCR) and solar cosmic rays (SCR) with bodies in the solar system is discussed, and what the record of that interaction reveals about the history of the solar system is considered. The influence of the energy, charge, and mass of the particles on the interaction is addressed, showing long-term average fluxes of solar protons, predicted production rates for heavy-nuclei tracks and various radionuclides as a function of depth in lunar rock, and integral fluxes of protons emitted by solar flares. The variation of the earth's magnetic field, the gardening of the lunar surface, and the source of meteorites and cosmic dust are studied using the cosmic ray record. The time variation of GCR, SCR, and VH and VVH nuclei is discussed for both the short and the long term.
Influence of Dust Loading on Atmospheric Ionizing Radiation on Mars
NASA Technical Reports Server (NTRS)
Norman, Ryan B.; Gronoff, Guillaume; Mertens, Christopher J.
2014-01-01
Measuring the radiation environment at the surface of Mars is the primary goal of the Radiation Assessment Detector on the NASA Mars Science Laboratory's Curiosity rover. One of the conditions that Curiosity will likely encounter is a dust storm. The objective of this paper is to compute the cosmic ray ionization in different conditions, including dust storms, as these various conditions are likely to be encountered by Curiosity at some point. In the present work, the Nowcast of Atmospheric Ionizing Radiation for Aviation Safety model, recently modified for Mars, was used along with the Badhwar & O'Neill 2010 galactic cosmic ray model. In addition to galactic cosmic rays, five different solar energetic particle event spectra were considered. For all input radiation environments, radiation dose throughout the atmosphere and at the surface was investigated as a function of atmospheric dust loading. It is demonstrated that for galactic cosmic rays, the ionization depends strongly on the atmosphere profile. Moreover, it is shown that solar energetic particle events strongly increase the ionization throughout the atmosphere, including ground level, and can account for the radio blackout conditions observed by the Mars Advanced Radar for Subsurface and Ionospheric Sounding instrument on the Mars Express spacecraft. These results demonstrate that the cosmic rays' influence on the Martian surface chemistry is strongly dependent on solar and atmospheric conditions that should be taken into account for future studies.
Cosmic web and environmental dependence of screening: Vainshtein vs. chameleon
DOE Office of Scientific and Technical Information (OSTI.GOV)
Falck, Bridget; Koyama, Kazuya; Zhao, Gong-Bo, E-mail: bridget.falck@port.ac.uk, E-mail: kazuya.koyama@port.ac.uk, E-mail: gong-bo.zhao@port.ac.uk
Theories which modify general relativity to explain the accelerated expansion of the Universe often use screening mechanisms to satisfy constraints on Solar System scales. We investigate the effects of the cosmic web and the local environmental density of dark matter halos on the screening properties of the Vainshtein and chameleon screening mechanisms. We compare the cosmic web morphology of dark matter particles, mass functions of dark matter halos, mass and radial dependence of screening, velocity dispersions and peculiar velocities, and environmental dependence of screening mechanisms in f(R) and nDGP models. Using the ORIGAMI cosmic web identification routine we find thatmore » the Vainshtein mechanism depends on the cosmic web morphology of dark matter particles, since these are defined according to the dimensionality of their collapse, while the chameleon mechanism shows no morphology dependence. The chameleon screening of halos and their velocity dispersions depend on halo mass, and small halos and subhalos can be environmentally screened in the chameleon mechanism. On the other hand, the screening of halos in the Vainshtein mechanism does not depend on mass nor environment, and their velocity dispersions are suppressed. The peculiar velocities of halos in the Vainshtein mechanism are enhanced because screened objects can still feel the fifth force generated by external fields, while peculiar velocities of chameleon halos are suppressed when the halo centers are screened.« less
Measurement of Neutron and Muon Fluxes 100~m Underground with the SciBath Detector
DOE Office of Scientific and Technical Information (OSTI.GOV)
Garrison, Lance
2014-01-01
The SciBath detector is an 80 liter liquid scintillator detector read out by a three dimensional grid of 768 wavelength-shifting fibers. Initially conceived as a fine-grained charged particle detector for neutrino studies that could image charged particle tracks in all directions, it is also sensitive to fast neutrons (15-200 MeV). In fall of 2011 the apparatus performed a three month run to measure cosmic-induced muons and neutrons 100~meters underground in the FNAL MINOS near-detector area. Data from this run has been analyzed and resulted in measurements of the cosmic muon flux as \
NASA Technical Reports Server (NTRS)
Forman, M. A.; Jokipii, J. R.
1978-01-01
The distribution function of cosmic rays streaming perpendicular to the mean magnetic field in a turbulent medium is reexamined. Urch's (1977) discovery that in quasi-linear theory, the flux is due to particles at 90 deg pitch angle is discussed and shown to be consistent with previous formulations of the theory. It is pointed out that this flux of particles at 90 deg cannot be arbitrarily set equal to zero, and hence the alternative theory which proceeds from this premise is dismissed. A further, basic inconsistency in Urch's transport equation is demonstrated, and the connection between quasi-linear theory and compound diffusion is discussed.
Difference method to search for the anisotropy of primary cosmic radiation
NASA Astrophysics Data System (ADS)
Pavlyuchenko, V. P.; Martirosov, R. M.; Nikolskaya, N. M.; Erlykin, A. D.
2018-01-01
The original difference method used in the search for an anisotropy of primary cosmic radiation at the knee region of its energy spectrum is considered. Its methodical features and properties are analyzed. It is shown that this method, in which properties of particle fluxes (rather than an intensity) are investigated, is stable against random experimental errors and allows one to separate anomalies connected with the laboratory coordinate system from anomalies in the celestial coordinate system. The method uses the multiple scattering of charged particles in the magnetic fields of the Galaxy to study the whole celestial sphere, including the regions outside the line of sight of the installation.
Space Radiation and Human Exposures, A Primer.
Nelson, Gregory A
2016-04-01
The space radiation environment is a complex field comprised primarily of charged particles spanning energies over many orders of magnitude. The principal sources of these particles are galactic cosmic rays, the Sun and the trapped radiation belts around the earth. Superimposed on a steady influx of cosmic rays and a steady outward flux of low-energy solar wind are short-term ejections of higher energy particles from the Sun and an 11-year variation of solar luminosity that modulates cosmic ray intensity. Human health risks are estimated from models of the radiation environment for various mission scenarios, the shielding of associated vehicles and the human body itself. Transport models are used to propagate the ambient radiation fields through realistic shielding levels and materials to yield radiation field models inside spacecraft. Then, informed by radiobiological experiments and epidemiology studies, estimates are made for various outcome measures associated with impairments of biological processes, losses of function or mortality. Cancer-associated risks have been formulated in a probabilistic model while management of non-cancer risks are based on permissible exposure limits. This article focuses on the various components of the space radiation environment and the human exposures that it creates.
NASA Technical Reports Server (NTRS)
Ferguson, F.; Lilleleht, L. U.; Nuth, J.; Stephens, J. R.; Bussoletti, E.; Colangeli, L.; Mennella, V.; Dell'Aversana, P.; Mirra, C.
1993-01-01
The formation, properties and chemical dynamics of microparticles are important in a wide variety of technical and scientific fields including synthesis of semiconductor crystals from the vapour, heterogeneous chemistry in the stratosphere and the formation of cosmic dust surrounding the stars. Gravitational effects on particle formation from vapors include gas convection and buoyancy and particle sedimentation. These processes can be significantly reduced by studying condensation and agglomeration of particles in microgravity. In addition, to accurately simulate particle formation near stars, which takes place under low gravity conditions, studies in microgravity are desired. We report here the STARDUST experience, a recent collaborative effort that brings together a successful American program of microgravity experiments on particle formation aboard NASA KC-135 Reduced Gravity Research Aircraft and several Italian research groups with expertise in microgravity research and astrophysical dust formation. The program goal is to study the formation and properties of high temperature particles and gases that are of interest in astrophysics and planetary science. To do so we are developing techniques that are generally applicable to study particle formation and properties, taking advantage of the microgravity environment to allow accurate control of system parameters.
NASA Astrophysics Data System (ADS)
Koleva, Rositza; Semkova, Jordanka; Krastev, Krasimir; Bankov, Nikolay; Malchev, Stefan; Benghin, Victor; Shurshakov, Vyacheslav
2017-04-01
The radiation field around the Earth is complex, composed of galactic cosmic rays, trapped particles of the Earth's radiation belts, solar energetic particles, albedo particles from the Earth's atmosphere and secondary radiation produced in the space vehicle shielding materials around the biological objects. Dose characteristics in near Earth and space radiation environment also depend on many other parameters such as the orbit parameters, solar cycle phase and current helio-and geophysical conditions. Since June 2007 till 2015 the Liulin-5 charged particle telescope has been observing the radiation characteristics in two different modules of the International Space Station (ISS). In the period from 2007 to 2009 measurements were conducted in the spherical tissue-equivalent phantom of MATROSHKA-R project located in the PIRS module of ISS. In the period from 2012 to 2015 measurements were conducted in and outside the phantom located in the Small Research Module of ISS. In this presentation attention is drawn to the obtained results for the dose rates, particle fluxes and dose equivalent rates in and outside the phantom from the galactic cosmic rays, trapped protons and solar energetic particle events which occurred in that period.
Ferguson, F; Lilleleht, L U; Nuth, J; Stephens, J R; Bussoletti, E; Colangeli, L; Mennella, V; Dell'Aversana, P; Mirra, C
1993-01-01
The formation, properties and chemical dynamics of microparticles are important in a wide variety of technical and scientific fields including synthesis of semiconductor crystals from the vapour, heterogeneous chemistry in the stratosphere and the formation of cosmic dust surrounding the stars. Gravitational effects on particle formation from vapors include gas convection and buoyancy and particle sedimentation. These processes can be significantly reduced by studying condensation and agglomeration of particles in microgravity. In addition, to accurately simulate particle formation near stars, which takes place under low gravity conditions, studies in microgravity are desired. We report here the STARDUST experience, a recent collaborative effort that brings together a successful American program of microgravity experiments on particle formation aboard NASA KC-135 Reduced Gravity Research Aircraft and several Italian research groups with expertise in microgravity research and astrophysical dust formation. The program goal is to study the formation and properties of high temperature particles and gases that are of interest in astrophysics and planetary science. To do so we are developing techniques that are generally applicable to study particle formation and properties, taking advantage of the microgravity environment to allow accurate control of system parameters.
Cooperative Research in High Energy Astrophysics
NASA Technical Reports Server (NTRS)
Trasco, John D.
1997-01-01
A joint agreement between NASA/Goddard and The University of Maryland currently supports cooperative research in Satellite Based Studies of Photons and Charged Particles in the following areas: 1) Detection of cosmic rays and studies of the solar modulation of galactic cosmic rays; 2) Research with several past and upcoming X-ray satellites; 3) High resolution gamma-ray spectroscopy of celestial sources; 4) Theoretical astrophysics.
High-energy multiple muons and heavy primary cosmic-rays
NASA Technical Reports Server (NTRS)
Mizutani, K.; Sato, T.; Takahashi, T.; Higashi, S.
1985-01-01
Three-dimensional simulations were carried out on high-energy multiple muons. On the lateral spread, the comparison with the deep underground observations indicates that the primary cosmic rays include heavy nuclei of high content. A method to determine the average mass number of primary particles in the energy around 10 to the 15th power eV is suggested.
Biostack: A study of the biological effects on HZE galactic cosmic radiation
NASA Technical Reports Server (NTRS)
Buecker, H.
1975-01-01
The Biostack experiment designed to study the effect of individual heavy nucleii of the cosmic radiation environment upon biological systems during actual space flight is described. In each Biostack, several thousand biological objects were hit by an HZE particle. The response of the biological objects was studied. Results are discussed in terms of sensitivity to the hit.
On galactic origin of cosmic rays with energy up to 10(19) eV
NASA Technical Reports Server (NTRS)
Efimov, N. N.; Mikhailov, A. A.
1985-01-01
The experimental data on ultrahigh energy cosmic ray anisotropy are considered. In supposed models of galactic magnetic field the main characteristics of expected anisotropy are estimated and are compared with the experimental data. It is shown that particles with energy up to 10 to the 19th power eV are of galactic origin.
Projects made with the Berkeley Lab Circuit Board
dependence of cosmic rays. Greg Poe, a student at Travis High School in Richmond, Texas, received an the journal Physics Education. He used the Berkeley Lab circuit board together with spare parts from New York Schools Cosmic Particle Telescope workshop. Ken Cecire has created a web page which describes
Ultrahigh-energy Cosmic Rays from Fanaroff Riley class II radio galaxies
NASA Astrophysics Data System (ADS)
Rachen, Joerg; Biermann, Peter L.
1992-08-01
The hot spots of very powerful radio galaxies (Fanaroff Riley class II) are argued to be the sources of the ultrahigh energy component in Cosmic Rays. We present calculations of Cosmic Ray transport in an evolving universe, taking the losses against the microwave background properly into account. As input we use the models for the cosmological radio source evolution derived by radioastronomers (mainly Peacock 1985). The model we adopt for the acceleration in the radio hot spots has been introduced by Biermann and Strittmatter (1987), and Meisenheimer et al. (1989) and is based on first order Fermi theory of particle acceleration at shocks (see, e.g., Drury 1983). As an unknown the actual proportion of energy density in protons enters, which together with structural uncertainties in the hot spots should introduce no more than one order of magnitude in uncertainty: We easily reproduce the observed spectra of high energy cosmic rays. It follows that scattering of charged energetic particles in intergalactic space must be sufficiently small in order to obtain contributions from sources as far away as even the nearest Fanaroff Riley class II radio galaxies. This implies a strong constraint on the turbulent magnetic field in intergalactic space.
NASA Technical Reports Server (NTRS)
Derrickson, J. H.; Wu, J.; Christl, M. J.; Fountain, W. F.; Parnell, T. A.
1999-01-01
The "all-particle" cosmic ray energy spectrum appears to be exhibiting a significant change in the spectral index just above approximately 3000 TeV. This could indicate (1) a change in the propagation of the cosmic rays in the galactic medium, and/or (2) the upper limit of the supernova shock wave acceleration mechanism, and/or (3) a new source of high-energy cosmic rays. Air shower and JACEE data indicate the spectral change is associated with a composition change to a heavier element mixture whereas DICE does not indicate this. A detector concept will be presented that utilizes the energy dependence of the production of direct Coulomb electron-positron pairs by energetic heavy ions. Monte Carlo simulations of a direct electron pair detector consisting of Pb target foils interleaved with planes of 1-mm square scintillating optical fibers will be discussed. The goal is to design a large area, non-saturating instrument to measure the energy spectrum of the individual cosmic ray elements in the "VH-group" for energies greater than 10 TeV/nucleon.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ortiz, E.; Valdés-Galicia, J. F.; Matsubara, Y.
In this work we report the flux of protons and neutral emission measured at the top of the Sierra Negra volcano at 4600 m.a.s.l. (575 g/cm2), in Eastern Mexico. As an example of the capability of the mini-SciCR as a cosmic ray detector we present the Forbush decrease recorded on March 7, 2012. These data were obtained with a cosmic ray detector prototype called mini-SciCR that was operating from October 2010 to July 2012. Our main aims were to measure the hadronic component flux of the secondary cosmic ray and to show the appropriate performance of all system of themore » detector. To separate the signals of protons from other charged particles we obtained the energy deposition pattern when they cross the detector using a Monte Carlo simulation, and to separate the signals of neutral emission we used an anticoincidence system between the edge bars and the internal bars of the detector. The mini-SciCR is a prototype of a new cosmic ray detector called SciBar Cosmic Ray Telescope (SciCRT) installed in the same place, which is in the process of calibration. The SciCRT will work mainly as a Solar Neutron and Muon Telescope, it is designed to achieve: (1) larger effective area than the current Solar Neutron Telescope, (2) higher energy resolution to determine the energy spectrum of solar neutrons, (3) lower energy threshold, and (4) higher particle identification ability.« less
Ortiz, E.; Valdés-Galicia, J. F.; Matsubara, Y.; ...
2016-02-16
In this study we report the flux of protons and neutral emission measured at the top of the Sierra Negra volcano at 4600 m.a.s.l. (575 g/cm 2), in Eastern Mexico. As an example of the capability of the mini-SciCR as a cosmic ray detector we present the Forbush decrease recorded on March 7, 2012. These data were obtained with a cosmic ray detector prototype called mini-SciCR that was operating from October 2010 to July 2012. Our main aims were to measure the hadronic component flux of the secondary cosmic ray and to show the appropriate performance of all system ofmore » the detector. To separate the signals of protons from other charged particles we obtained the energy deposition pattern when they cross the detector using a Monte Carlo simulation, and to separate the signals of neutral emission we used an anticoincidence system between the edge bars and the internal bars of the detector. The mini-SciCR is a prototype of a new cosmic ray detector called SciBar Cosmic Ray Telescope (SciCRT) installed in the same place, which is in the process of calibration. The SciCRT will work mainly as a Solar Neutron and Muon Telescope, it is designed to achieve: (1) larger effective area than the current Solar Neutron Telescope, (2) higher energy resolution to determine the energy spectrum of solar neutrons, (3) lower energy threshold, and (4) higher particle identification ability.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ortiz, E.; Valdés-Galicia, J. F.; Matsubara, Y.
In this study we report the flux of protons and neutral emission measured at the top of the Sierra Negra volcano at 4600 m.a.s.l. (575 g/cm 2), in Eastern Mexico. As an example of the capability of the mini-SciCR as a cosmic ray detector we present the Forbush decrease recorded on March 7, 2012. These data were obtained with a cosmic ray detector prototype called mini-SciCR that was operating from October 2010 to July 2012. Our main aims were to measure the hadronic component flux of the secondary cosmic ray and to show the appropriate performance of all system ofmore » the detector. To separate the signals of protons from other charged particles we obtained the energy deposition pattern when they cross the detector using a Monte Carlo simulation, and to separate the signals of neutral emission we used an anticoincidence system between the edge bars and the internal bars of the detector. The mini-SciCR is a prototype of a new cosmic ray detector called SciBar Cosmic Ray Telescope (SciCRT) installed in the same place, which is in the process of calibration. The SciCRT will work mainly as a Solar Neutron and Muon Telescope, it is designed to achieve: (1) larger effective area than the current Solar Neutron Telescope, (2) higher energy resolution to determine the energy spectrum of solar neutrons, (3) lower energy threshold, and (4) higher particle identification ability.« less
Cosmic-Ray Extremely Distributed Observatory: a global cosmic ray detection framework
NASA Astrophysics Data System (ADS)
Sushchov, O.; Homola, P.; Dhital, N.; Bratek, Ł.; Poznański, P.; Wibig, T.; Zamora-Saa, J.; Almeida Cheminant, K.; Alvarez Castillo, D.; Góra, D.; Jagoda, P.; Jałocha, J.; Jarvis, J. F.; Kasztelan, M.; Kopański, K.; Krupiński, M.; Michałek, M.; Nazari, V.; Smelcerz, K.; Smolek, K.; Stasielak, J.; Sułek, M.
2017-12-01
The main objective of the Cosmic-Ray Extremely Distributed Observatory (CREDO) is the detection and analysis of extended cosmic ray phenomena, so-called super-preshowers (SPS), using existing as well as new infrastructure (cosmic-ray observatories, educational detectors, single detectors etc.). The search for ensembles of cosmic ray events initiated by SPS is yet an untouched ground, in contrast to the current state-of-the-art analysis, which is focused on the detection of single cosmic ray events. Theoretical explanation of SPS could be given either within classical (e.g., photon-photon interaction) or exotic (e.g., Super Heavy Dark Matter decay or annihilation) scenarios, thus detection of SPS would provide a better understanding of particle physics, high energy astrophysics and cosmology. The ensembles of cosmic rays can be classified based on the spatial and temporal extent of particles constituting the ensemble. Some classes of SPS are predicted to have huge spatial distribution, a unique signature detectable only with a facility of the global size. Since development and commissioning of a completely new facility with such requirements is economically unwarranted and time-consuming, the global analysis goals are achievable when all types of existing detectors are merged into a worldwide network. The idea to use the instruments in operation is based on a novel trigger algorithm: in parallel to looking for neighbour surface detectors receiving the signal simultaneously, one should also look for spatially isolated stations clustered in a small time window. On the other hand, CREDO strategy is also aimed at an active engagement of a large number of participants, who will contribute to the project by using common electronic devices (e.g., smartphones), capable of detecting cosmic rays. It will help not only in expanding the geographical spread of CREDO, but also in managing a large manpower necessary for a more efficient crowd-sourced pattern recognition scheme to 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.
HILT - A heavy ion large area proportional counter telescope for solar and anomalous cosmic rays
NASA Technical Reports Server (NTRS)
Klecker, Berndt; Hovestadt, Dietrich; Scholer, M.; Arbinger, H.; Ertl, M.; Kaestle, H.; Kuenneth, E.; Laeverenz, P.; Seidenschwang, E.; Blake, J. B.
1993-01-01
The HILT sensor has been designed to measure heavy ion elemental abundances, energy spectra, and direction of incidence in the mass range from He to Fe and in the energy range 4 to 250 MeV/nucleon. With its large geometric factor of 60 sq cm sr the sensor is optimized to provide compositional and spectral measurements for low intensity cosmic rays (i.e. for small solar energetic particle events and for the anomalous component of cosmic rays). The instrument combines a large area ion drift chamber-proportional counter system with two arrays of 16 Li-drift solid state detectors and 16 CsI crystals. The multi dE/dx-E technique provides a low background mass and energy determination. The sensor also measures particle direction. Combining these measurements with the information on the spacecraft position and attitude in the low-altitude polar orbit, it will be possible to infer the ionic charge of the ions from the local cutoff of the Earth's magnetic field. The ionic charge in this energy range is of particular interest because it provides unique clues to the origin of these particles and has not been investigated systematically so far. Together with the other instruments on board SAMPEX (LEICA, MAST, and PET), a comprehensive measurement of the entire solar and anomalous particle population will be achieved.
Charm contribution to the atmospheric neutrino flux
NASA Astrophysics Data System (ADS)
Halzen, Francis; Wille, Logan
2016-07-01
We revisit the estimate of the charm particle contribution to the atmospheric neutrino flux that is expected to dominate at high energies because long-lived high-energy pions and kaons interact in the atmosphere before decaying into neutrinos. We focus on the production of forward charm particles which carry a large fraction of the momentum of the incident proton. In the case of strange particles, such a component is familiar from the abundant production of K+Λ pairs. These forward charm particles can dominate the high-energy atmospheric neutrino flux in underground experiments. Modern collider experiments have no coverage in the very large rapidity region where charm forward pair production dominates. Using archival accelerator data as well as IceCube measurements of atmospheric electron and muon neutrino fluxes, we obtain an upper limit on forward D¯0Λc pair production and on the associated flux of high-energy atmospheric neutrinos. We conclude that the prompt flux may dominate the much-studied central component and represent a significant contribution to the TeV atmospheric neutrino flux. Importantly, it cannot accommodate the PeV flux of high-energy cosmic neutrinos, or the excess of events observed by IceCube in the 30-200 TeV energy range indicating either structure in the flux of cosmic accelerators, or a presence of more than one component in the cosmic flux observed.
Calculation of Radiation Protection Quantities and Analysis of Astronaut Orientation Dependence
NASA Technical Reports Server (NTRS)
Clowdsley, Martha S.; Nealy, John E.; Atwell, William; Anderson, Brooke M.; Luetke, Nathan J.; Wilson, John W.
2006-01-01
Health risk to astronauts due to exposure to ionizing radiation is a primary concern for exploration missions and may become the limiting factor for long duration missions. Methodologies for evaluating this risk in terms of radiation protection quantities such as dose, dose equivalent, gray equivalent, and effective dose are described. Environment models (galactic cosmic ray and solar particle event), vehicle/habitat geometry models, human geometry models, and transport codes are discussed and sample calculations for possible lunar and Mars missions are used as demonstrations. The dependence of astronaut health risk, in terms of dosimetric quantities, on astronaut orientation within a habitat is also examined. Previous work using a space station type module exposed to a proton spectrum modeling the October 1989 solar particle event showed that reorienting the astronaut within the module could change the calculated dose equivalent by a factor of two or more. Here the dose equivalent to various body tissues and the whole body effective dose due to both galactic cosmic rays and a solar particle event are calculated for a male astronaut in two different orientations, vertical and horizontal, in a representative lunar habitat. These calculations also show that the dose equivalent at some body locations resulting from a solar particle event can vary by a factor of two or more, but that the dose equivalent due to galactic cosmic rays has a much smaller (<15%) dependence on astronaut orientation.
Scattering Properties of Large Irregular Cosmic Dust Particles at Visible Wavelengths
DOE Office of Scientific and Technical Information (OSTI.GOV)
Escobar-Cerezo, J.; Palmer, C.; Muñoz, O.
The effect of internal inhomogeneities and surface roughness on the scattering behavior of large cosmic dust particles is studied by comparing model simulations with laboratory measurements. The present work shows the results of an attempt to model a dust sample measured in the laboratory with simulations performed by a ray-optics model code. We consider this dust sample as a good analogue for interplanetary and interstellar dust as it shares its refractive index with known materials in these media. Several sensitivity tests have been performed for both structural cases (internal inclusions and surface roughness). Three different samples have been selected tomore » mimic inclusion/coating inhomogeneities: two measured scattering matrices of hematite and white clay, and a simulated matrix for water ice. These three matrices are selected to cover a wide range of imaginary refractive indices. The selection of these materials also seeks to study astrophysical environments of interest such as Mars, where hematite and clays have been detected, and comets. Based on the results of the sensitivity tests shown in this work, we perform calculations for a size distribution of a silicate-type host particle model with inclusions and surface roughness to reproduce the experimental measurements of a dust sample. The model fits the measurements quite well, proving that surface roughness and internal structure play a role in the scattering pattern of irregular cosmic dust particles.« less
Research in particles and fields
NASA Technical Reports Server (NTRS)
Vogt, R. E.; Buffington, A.; Davis, L., Jr.; Stone, E. C.
1982-01-01
The astrophysical aspects of cosmic radiation and the radiation and electromagnetic field environment of the Earth and other planets are investigated. Energetic particle and photon detector systems flown on spacecraft and balloons are used. Galactic, solar, interplanetary, and planetary energetic particles and plasmas are also studied with emphasis on precision measurements with high resolution in charge, mass, and energy.
NASA Technical Reports Server (NTRS)
Le Roux, J. A.; Ptuskin, V. S.
1995-01-01
Realistic models of the outer heliosphere should consider that the interstellar cosmic-ray pressure becomes comparable to pressures in the solar wind at distances more than 100 AU from the Sun. The cosmic-ray pressure dynamically affects solar wind flow through deceleration. This effect, which occurs over a scale length of the order of the effective diffusion length at large radial distances, has important implications for cosmic-ray modulation and acceleration. As a first step toward solution of this nonlinear problem, a steady state numerical model was developed for a relatively cold spherical solar wind flow which encounters the confining isotropic pressure of the surrounding Galactic medium. This pressure is assumed to be dominated by energetic particles (Galactic cosmic rays). The system of equations, which are solved self-consistently, includes the relevant hydrodynamical equations for the solar wind flow and the spherical cosmic-ray transport equation. To avoid the closure parameter problem of the two-fluid model, the latter equation is solved for the energy-dependent cosmic-ray distribution function.
Constraining the p¯/p ratio in TeV cosmic rays with observations of the Moon shadow by HAWC
NASA Astrophysics Data System (ADS)
Abeysekara, A. U.; Albert, A.; Alfaro, R.; Alvarez, C.; Álvarez, J. D.; Arceo, R.; Arteaga-Velázquez, J. C.; Avila Rojas, D.; Ayala Solares, H. A.; Belmont-Moreno, E.; BenZvi, S. Y.; Braun, J.; Brisbois, C.; Caballero-Mora, K. S.; Capistrán, T.; Carramiñana, A.; Casanova, S.; Castillo, M.; Cotti, U.; Cotzomi, J.; Coutiño de León, S.; De León, C.; De la Fuente, E.; Diaz Hernandez, R.; Dichiara, S.; Dingus, B. L.; DuVernois, M. A.; Ellsworth, R. W.; Engel, K.; Enríquez-Rivera, O.; Fleischhack, H.; Fraija, N.; Galván-Gámez, A.; García-González, J. A.; González Muñoz, A.; González, M. M.; Hampel-Arias, Z.; Harding, J. P.; Hernandez, S.; Hona, B.; Hueyotl-Zahuantitla, F.; Hui, C. M.; Hüntemeyer, P.; Iriarte, A.; Jardin-Blicq, A.; Joshi, V.; Kaufmann, S.; Lara, A.; Lee, W. H.; León Vargas, H.; Linnemann, J. T.; Longinotti, A. L.; Luis-Raya, G.; Luna-García, R.; López-Coto, R.; Malone, K.; Marinelli, S. S.; Martinez, O.; Martinez-Castellanos, I.; Martínez-Castro, J.; Martínez-Huerta, H.; Matthews, J. A.; Miranda-Romagnoli, P.; Moreno, E.; Mostafá, M.; Nellen, L.; Newbold, M.; Nisa, M. U.; Noriega-Papaqui, R.; Pelayo, R.; Pretz, J.; Pérez-Pérez, E. G.; Ren, Z.; Rho, C. D.; Rivière, C.; Rosa-González, D.; Rosenberg, M.; Ruiz-Velasco, E.; Salesa Greus, F.; Sandoval, A.; Schneider, M.; Schoorlemmer, H.; Seglar Arroyo, M.; Sinnis, G.; Smith, A. J.; Springer, R. W.; Surajbali, P.; Taboada, I.; Tibolla, O.; Torres, I.; Villaseñor, L.; Weisgarber, T.; Westerhoff, S.; Wood, J.; Yapici, T.; Yodh, G. B.; Zepeda, A.; Zhou, H.; HAWC Collaboration
2018-05-01
An indirect measurement of the antiproton flux in cosmic rays is possible as the particles undergo deflection by the geomagnetic field. This effect can be measured by studying the deficit in the flux, or shadow, created by the Moon as it absorbs cosmic rays that are headed toward the Earth. The shadow is displaced from the actual position of the Moon due to geomagnetic deflection, which is a function of the energy and charge of the cosmic rays. The displacement provides a natural tool for momentum/charge discrimination that can be used to study the composition of cosmic rays. Using 33 months of data comprising more than 80 billion cosmic rays measured by the High Altitude Water Cherenkov observatory, we have analyzed the Moon shadow to search for TeV antiprotons in cosmic rays. We present our first upper limits on the p ¯/p fraction, which in the absence of any direct measurements provide the tightest available constraints of ˜1 % on the antiproton fraction for energies between 1 and 10 TeV.
NASA Astrophysics Data System (ADS)
Guo, Yi-Qing; Yuan, Qiang
2018-03-01
Recent direct measurements of Galactic cosmic ray spectra by balloon/space-borne detectors reveal spectral hardenings of all major nucleus species at rigidities of a few hundred GV. The all-sky diffuse γ -ray emissions measured by the Fermi Large Area Telescope also show spatial variations of the intensities and spectral indices of cosmic rays. These new observations challenge the traditional simple acceleration and/or propagation scenario of Galactic cosmic rays. In this work, we propose a spatially dependent diffusion scenario to explain all these phenomena. The diffusion coefficient is assumed to be anticorrelated with the source distribution, which is a natural expectation from the charged particle transportation in a turbulent magnetic field. The spatially dependent diffusion model also gives a lower level of anisotropies of cosmic rays, which are consistent with observations by underground muons and air shower experiments. The spectral variations of cosmic rays across the Galaxy can be properly reproduced by this model.
The KASCADE-Grande observatory and the composition of very high-energy cosmic rays
NASA Astrophysics Data System (ADS)
Arteaga-Velázquez, J. C.; Apel, W. D.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Fuchs, B.; Fuhrmann, D.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huber, D.; Huege, T.; Kampert, K.-H.; Kang, D.; Klages, H. O.; Link, K.; Łuczak, P.; Ludwig, M.; Mathes, H. J.; Mayer, H. J.; Melissas, M.; Milke, J.; Mitrica, B.; Morello, C.; Oehlschläger, J.; Ostapchenko, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Zabierowski, J.
2015-11-01
KASCADE-Grande is an air-shower observatory devoted to the detection of cosmic rays with energies in the range of 1016 to 1018 eV. This energy region is of particular interest for the cosmic ray astrophysics, since it is the place where some models predict the existence of a transition from galactic to extragalactic origin of cosmic rays and the presence of a break in the flux of its heavy component. The detection of these features requires detailed and simultaneous measurements of the energy and composition of cosmic rays with sufficient statistics. These kinds of studies are possible for the first time in KASCADE-Grande due to the accurate measurements of several air-shower observables, i.e., the number of charged particles, electrons and muons in the shower, using the different detector systems of the observatory. In this contribution, a detailed look into the composition of 1016 — 1018 eV cosmic rays with KASCADE-Grande is presented.
NASA Astrophysics Data System (ADS)
IceCube Collaboration; Abbasi, R.; Abdou, Y.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Altmann, D.; Andeen, K.; Auffenberg, J.; Bai, X.; Baker, M.; Barwick, S. W.; Baum, V.; Bay, R.; Beattie, K.; Beatty, J. J.; Bechet, S.; Becker, J. K.; Becker, K.-H.; Bell, M.; Benabderrahmane, M. L.; BenZvi, S.; Berdermann, J.; Berghaus, P.; Berley, D.; Bernardini, E.; Bertrand, D.; Besson, D. Z.; Bindig, D.; Bissok, M.; Blaufuss, E.; Blumenthal, J.; Boersma, D. J.; Bohm, C.; Bose, D.; Böser, S.; Botner, O.; Brayeur, L.; Brown, A. M.; Bruijn, R.; Brunner, J.; Buitink, S.; Caballero-Mora, K. S.; Carson, M.; Casey, J.; Casier, M.; Chirkin, D.; Christy, B.; Clevermann, F.; Cohen, S.; Cowen, D. F.; Silva, A. H. Cruz; Danninger, M.; Daughhetee, J.; Davis, J. C.; De Clercq, C.; Descamps, F.; Desiati, P.; de Vries-Uiterweerd, G.; DeYoung, T.; Díaz-Vélez, J. C.; Dreyer, J.; Dumm, J. P.; Dunkman, M.; Eagan, R.; Eisch, J.; Ellsworth, R. W.; Engdegård, O.; Euler, S.; Evenson, P. A.; Fadiran, O.; Fazely, A. R.; Fedynitch, A.; Feintzeig, J.; Feusels, T.; Filimonov, K.; Finley, C.; Fischer-Wasels, T.; Flis, S.; Franckowiak, A.; Franke, R.; Frantzen, K.; Fuchs, T.; Gaisser, T. K.; Gallagher, J.; Gerhardt, L.; Gladstone, L.; Glüsenkamp, T.; Goldschmidt, A.; Goodman, J. A.; Góra, D.; Grant, D.; Groß, A.; Grullon, S.; Gurtner, M.; Ha, C.; Ismail, A. Haj; Hallgren, A.; Halzen, F.; Hanson, K.; Heereman, D.; Heimann, P.; Heinen, D.; Helbing, K.; Hellauer, R.; Hickford, S.; Hill, G. C.; Hoffman, K. D.; Hoffmann, R.; Homeier, A.; Hoshina, K.; Huelsnitz, W.; Hulth, P. O.; Hultqvist, K.; Hussain, S.; Ishihara, A.; Jacobi, E.; Jacobsen, J.; Japaridze, G. S.; Jlelati, O.; Johansson, H.; Kappes, A.; Karg, T.; Karle, A.; Kiryluk, J.; Kislat, F.; Kläs, J.; Klein, S. R.; Köhne, J.-H.; Kohnen, G.; Kolanoski, H.; Köpke, L.; Kopper, C.; Kopper, S.; Koskinen, D. J.; Kowalski, M.; Krasberg, M.; Kroll, G.; Kunnen, J.; Kurahashi, N.; Kuwabara, T.; Labare, M.; Laihem, K.; Landsman, H.; Larson, M. J.; Lauer, R.; Lesiak-Bzdak, M.; Lünemann, J.; Madsen, J.; Maruyama, R.; Mase, K.; Matis, H. S.; McNally, F.; Meagher, K.; Merck, M.; Mészáros, P.; Meures, T.; Miarecki, S.; Middell, E.; Milke, N.; Miller, J.; Mohrmann, L.; Montaruli, T.; Morse, R.; Movit, S. M.; Nahnhauer, R.; Naumann, U.; Nowicki, S. C.; Nygren, D. R.; Obertacke, A.; Odrowski, S.; Olivas, A.; Olivo, M.; O'Murchadha, A.; Panknin, S.; Paul, L.; Pepper, J. A.; de los Heros, C. Pérez; Pieloth, D.; Pirk, N.; Posselt, J.; Price, P. B.; Przybylski, G. T.; Rädel, L.; Rawlins, K.; Redl, P.; Resconi, E.; Rhode, W.; Ribordy, M.; Richman, M.; Riedel, B.; Rodrigues, J. P.; Rothmaier, F.; Rott, C.; Ruhe, T.; Rutledge, D.; Ruzybayev, B.; Ryckbosch, D.; Salameh, T.; Sander, H.-G.; Santander, M.; Sarkar, S.; Saba, S. M.; Schatto, K.; Scheel, M.; Scheriau, F.; Schmidt, T.; Schmitz, M.; Schoenen, S.; Schöneberg, S.; Schönherr, L.; Schönwald, A.; Schukraft, A.; Schulte, L.; Schulz, O.; Seckel, D.; Seo, S. H.; Sestayo, Y.; Seunarine, S.; Smith, M. W. E.; Soiron, M.; Soldin, D.; Spiczak, G. M.; Spiering, C.; Stamatikos, M.; Stanev, T.; Stasik, A.; Stezelberger, T.; Stokstad, R. G.; Stößl, A.; Strahler, E. A.; Ström, R.; Sullivan, G. W.; Taavola, H.; Taboada, I.; Tamburro, A.; Ter-Antonyan, S.; Tilav, S.; Toale, P. A.; Toscano, S.; Usner, M.; van Eijndhoven, N.; van der Drift, D.; Van Overloop, A.; van Santen, J.; Vehring, M.; Voge, M.; Walck, C.; Waldenmaier, T.; Wallraff, M.; Walter, M.; Wasserman, R.; Weaver, Ch.; Wendt, C.; Westerhoff, S.; Whitehorn, N.; Wiebe, K.; Wiebusch, C. H.; Williams, D. R.; Wissing, H.; Wolf, M.; Wood, T. R.; Woschnagg, K.; Xu, C.; Xu, D. L.; Xu, X. W.; Yanez, J. P.; Yodh, G.; Yoshida, S.; Zarzhitsky, P.; Ziemann, J.; Zilles, A.; Zoll, M.
2013-02-01
The mass composition of high energy cosmic rays depends on their production, acceleration, and propagation. The study of cosmic ray composition can therefore reveal hints of the origin of these particles. At the South Pole, the IceCube Neutrino Observatory is capable of measuring two components of cosmic ray air showers in coincidence: the electromagnetic component at high altitude (2835 m) using the IceTop surface array, and the muonic component above ˜1 TeV using the IceCube array. This unique detector arrangement provides an opportunity for precision measurements of the cosmic ray energy spectrum and composition in the region of the knee and beyond. We present the results of a neural network analysis technique to study the cosmic ray composition and the energy spectrum from 1 PeV to 30 PeV using data recorded using the 40-string/40-station configuration of the IceCube Neutrino Observatory.
Radio-wave detection of ultra-high-energy neutrinos and cosmic rays
NASA Astrophysics Data System (ADS)
Huege, Tim; Besson, Dave
2017-12-01
Radio waves, perhaps because our terrestrial atmosphere and the cosmos beyond are uniquely transparent to them, or perhaps because they are macroscopic, so the basic instruments of detection (antennas) are easily constructible, arguably occupy a privileged position within the electromagnetic spectrum, and, correspondingly, receive disproportionate attention experimentally. Detection of radio-frequency radiation, at macroscopic wavelengths, has blossomed within the last decade as a competitive method for the measurement of cosmic particles, particularly charged cosmic rays and neutrinos. Cosmic-ray detection via radio emission from extensive air showers has been demonstrated to be a reliable technique that has reached a reconstruction quality of the cosmic-ray parameters competitive with more traditional approaches. Radio detection of neutrinos in dense media seems to be the most promising technique to achieve the gigantic detection volumes required to measure neutrinos at energies beyond the PeV-scale flux established by IceCube. In this article, we review radio detection both of cosmic rays in the atmosphere, as well as neutrinos in dense media.
Lateral distribution of muons in IceCube cosmic ray events
NASA Astrophysics Data System (ADS)
Abbasi, R.; Abdou, Y.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Altmann, D.; Andeen, K.; Auffenberg, J.; Bai, X.; Baker, M.; Barwick, S. W.; Baum, V.; Bay, R.; Beattie, K.; Beatty, J. J.; Bechet, S.; Becker Tjus, J.; Becker, K.-H.; Bell, M.; Benabderrahmane, M. L.; BenZvi, S.; Berdermann, J.; Berghaus, P.; Berley, D.; Bernardini, E.; Bertrand, D.; Besson, D. Z.; Bindig, D.; Bissok, M.; Blaufuss, E.; Blumenthal, J.; Boersma, D. J.; Bohm, C.; Bose, D.; Böser, S.; Botner, O.; Brayeur, L.; Brown, A. M.; Bruijn, R.; Brunner, J.; Buitink, S.; Carson, M.; Casey, J.; Casier, M.; Chirkin, D.; Christy, B.; Clevermann, F.; Cohen, S.; Cowen, D. F.; Cruz Silva, A. H.; Danninger, M.; Daughhetee, J.; Davis, J. C.; De Clercq, C.; Descamps, F.; Desiati, P.; de Vries-Uiterweerd, G.; DeYoung, T.; Díaz-Vélez, J. C.; Dreyer, J.; Dumm, J. P.; Dunkman, M.; Eagan, R.; Eisch, J.; Ellsworth, R. W.; Engdegård, O.; Euler, S.; Evenson, P. A.; Fadiran, O.; Fazely, A. R.; Fedynitch, A.; Feintzeig, J.; Feusels, T.; Filimonov, K.; Finley, C.; Fischer-Wasels, T.; Flis, S.; Franckowiak, A.; Franke, R.; Frantzen, K.; Fuchs, T.; Gaisser, T. K.; Gallagher, J.; Gerhardt, L.; Gladstone, L.; Glüsenkamp, T.; Goldschmidt, A.; Goodman, J. A.; Góra, D.; Grant, D.; Groß, A.; Grullon, S.; Gurtner, M.; Ha, C.; Haj Ismail, A.; Hallgren, A.; Halzen, F.; Hanson, K.; Heereman, D.; Heimann, P.; Heinen, D.; Helbing, K.; Hellauer, R.; Hickford, S.; Hill, G. C.; Hoffman, K. D.; Hoffmann, R.; Homeier, A.; Hoshina, K.; Huelsnitz, W.; Hulth, P. O.; Hultqvist, K.; Hussain, S.; Ishihara, A.; Jacobi, E.; Jacobsen, J.; Japaridze, G. S.; Jlelati, O.; Kappes, A.; Karg, T.; Karle, A.; Kiryluk, J.; Kislat, F.; Kläs, J.; Klein, S. R.; Köhne, J.-H.; Kohnen, G.; Kolanoski, H.; Köpke, L.; Kopper, C.; Kopper, S.; Koskinen, D. J.; Kowalski, M.; Krasberg, M.; Kroll, G.; Kunnen, J.; Kurahashi, N.; Kuwabara, T.; Labare, M.; Laihem, K.; Landsman, H.; Larson, M. J.; Lauer, R.; Lesiak-Bzdak, M.; Lünemann, J.; Madsen, J.; Maruyama, R.; Mase, K.; Matis, H. S.; McNally, F.; Meagher, K.; Merck, M.; Mészáros, P.; Meures, T.; Miarecki, S.; Middell, E.; Milke, N.; Miller, J.; Mohrmann, L.; Montaruli, T.; Morse, R.; Movit, S. M.; Nahnhauer, R.; Naumann, U.; Nowicki, S. C.; Nygren, D. R.; Obertacke, A.; Odrowski, S.; Olivas, A.; Olivo, M.; O'Murchadha, A.; Panknin, S.; Paul, L.; Pepper, J. A.; Pérez de los Heros, C.; Pieloth, D.; Pirk, N.; Posselt, J.; Price, P. B.; Przybylski, G. T.; Rädel, L.; Rawlins, K.; Redl, P.; Resconi, E.; Rhode, W.; Ribordy, M.; Richman, M.; Riedel, B.; Rodrigues, J. P.; Rothmaier, F.; Rott, C.; Ruhe, T.; Ruzybayev, B.; Ryckbosch, D.; Saba, S. M.; Salameh, T.; Sander, H.-G.; Santander, M.; Sarkar, S.; Schatto, K.; Scheel, M.; Scheriau, F.; Schmidt, T.; Schmitz, M.; Schoenen, S.; Schöneberg, S.; Schönherr, L.; Schönwald, A.; Schukraft, A.; Schulte, L.; Schulz, O.; Seckel, D.; Seo, S. H.; Sestayo, Y.; Seunarine, S.; Smith, M. W. E.; Soiron, M.; Soldin, D.; Spiczak, G. M.; Spiering, C.; Stamatikos, M.; Stanev, T.; Stasik, A.; Stezelberger, T.; Stokstad, R. G.; Stößl, A.; Strahler, E. A.; Ström, R.; Sullivan, G. W.; Taavola, H.; Taboada, I.; Tamburro, A.; Ter-Antonyan, S.; Tilav, S.; Toale, P. A.; Toscano, S.; Usner, M.; van der Drift, D.; van Eijndhoven, N.; Van Overloop, A.; van Santen, J.; Vehring, M.; Voge, M.; Walck, C.; Waldenmaier, T.; Wallraff, M.; Walter, M.; Wasserman, R.; Weaver, Ch.; Wendt, C.; Westerhoff, S.; Whitehorn, N.; Wiebe, K.; Wiebusch, C. H.; Williams, D. R.; Wissing, H.; Wolf, M.; Wood, T. R.; Woschnagg, K.; Xu, C.; Xu, D. L.; Xu, X. W.; Yanez, J. P.; Yodh, G.; Yoshida, S.; Zarzhitsky, P.; Ziemann, J.; Zilles, A.; Zoll, M.
2013-01-01
In cosmic ray air showers, the muon lateral separation from the center of the shower is a measure of the transverse momentum that the muon parent acquired in the cosmic ray interaction. IceCube has observed cosmic ray interactions that produce muons laterally separated by up to 400 m from the shower core, a factor of 6 larger distance than previous measurements. These muons originate in high pT (>2GeV/c) interactions from the incident cosmic ray, or high-energy secondary interactions. The separation distribution shows a transition to a power law at large values, indicating the presence of a hard pT component that can be described by perturbative quantum chromodynamics. However, the rates and the zenith angle distributions of these events are not well reproduced with the cosmic ray models tested here, even those that include charm interactions. This discrepancy may be explained by a larger fraction of kaons and charmed particles than is currently incorporated in the simulations.
A graphics-card implementation of Monte-Carlo simulations for cosmic-ray transport
NASA Astrophysics Data System (ADS)
Tautz, R. C.
2016-05-01
A graphics card implementation of a test-particle simulation code is presented that is based on the CUDA extension of the C/C++ programming language. The original CPU version has been developed for the calculation of cosmic-ray diffusion coefficients in artificial Kolmogorov-type turbulence. In the new implementation, the magnetic turbulence generation, which is the most time-consuming part, is separated from the particle transport and is performed on a graphics card. In this article, the modification of the basic approach of integrating test particle trajectories to employ the SIMD (single instruction, multiple data) model is presented and verified. The efficiency of the new code is tested and several language-specific accelerating factors are discussed. For the example of isotropic magnetostatic turbulence, sample results are shown and a comparison to the results of the CPU implementation is performed.
Shock waves raised by explosions in space as sources of ultra-high-energy cosmic rays
NASA Astrophysics Data System (ADS)
Kichigin, Gennadiy
2015-03-01
The paper discusses the possibility of particle acceleration up to ultrahigh energies in the relativistic waves generated by various explosive processes in the interstellar medium. We propose to use the surfatron mechanism of acceleration (surfing) of charged particles trapped in the front of relativistic waves as a generator of high-energy cosmic rays (CRs). Conditions under which surfing in these waves can be made are studied thoroughly. Ultra-high-energy CRs (up to 10^20 eV) are shown to be obtained due to the surfing in the relativistic plane and spherical waves. Surfing is supposed to take place in nonlinear Langmuir waves excited by powerful electromagnetic radiation or relativistic beams of charged particles, as well as in strong shock waves generated by relativistic jets or spherical formations that expand fast (fireballs).
Cosmic-ray streaming and anisotropies
NASA Technical Reports Server (NTRS)
Forman, M. A.; Gleeson, L. J.
1975-01-01
The paper is concerned with the differential current densities and anisotropies that exist in the interplanetary cosmic-ray gas, and in particular with a correct formulation and simple interpretation of the momentum equation that describes these on a local basis. Two examples of the use of this equation in the interpretation of previous data are given. It is demonstrated that in interplanetary space, the electric-field drifts and convective flow parallel to the magnetic field of cosmic-ray particles combine as a simple convective flow with the solar wind, and that there exist diffusive currents and transverse gradient drift currents. Thus direct reference to the interplanetary electric-field drifts is eliminated, and the study of steady-state and transient cosmic-ray anisotropies is both more systematic and simpler.
NASA Astrophysics Data System (ADS)
Monkhoev, R. D.; Budnev, N. M.; Chiavassa, A.; Dyachok, A. N.; Gafarov, A. R.; Gress, O. A.; Gress, T. I.; Grishin, O. G.; Ivanova, A. L.; Kalmykov, N. N.; Kazarina, Yu. A.; Korosteleva, E. E.; Kozhin, V. A.; Kuzmichev, L. A.; Lenok, V. V.; Lubsandorzhiev, B. K.; Lubsandorzhiev, N. B.; Mirgazov, R. R.; Mirzoyan, R.; Osipova, E. A.; Pakhorukov, A. L.; Panasyuk, M. I.; Pankov, L. V.; Poleschuk, V. A.; Popova, E. G.; Postnikov, E. B.; Prosin, V. V.; Ptuskin, V. S.; Pushnin, A. A.; Samoliga, V. S.; Semeney, Y. A.; Sveshnikova, L. G.; Silaev, A. A.; Silaev, A. A., Jr.; Skurikhin, A. V.; Sulakov, V. P.; Tabolenko, V. A.; Voronin, D. M.; Fedorov, O. L.; Spiering, C.; Zagorodnikov, A. V.; Zhurov, D. P.; Zurbanov, V. L.
2017-06-01
The investigation of energy spectrum and mass composition of primary cosmic rays in the energy range 1016-1018 eV and the search for diffuse cosmic gamma rays are of the great interest for understanding mechanisms and nature of high-energy particle sources, the problem of great importance in modern astrophysics. Tunka-Grande scintillator array is a part of the experimental complex TAIGA (Tunka Advanced Instrument for Cosmic Ray and Gamma Astronomy) which is located in the Tunka Valley, about 50 km from Lake Baikal. The purpose of this array is the study of diffuse gamma rays and cosmic rays of ultra-high energies by detecting extensive air showers. We describe the design, specifications of the read-out, data acquisition (DAQ) and control systems of the array.
Results from Two Low Mass Cosmic Ray Experiments Flown on the HASP Platform
NASA Astrophysics Data System (ADS)
Fontenot, R. S.; Hollerman, W. A.; Tittsworth, M.; Fountain, W.; Christl, M.; Thibodaux, C.; Broussard, B. M.
2009-03-01
The High Altitude Student Payload (HASP) program is designed to carry twelve student experiments to an altitude of about 123,000 feet (˜37 km). In 2006, students participated in the first HASP launch to measure cosmic ray intensities using traditional film and absorbers. This 10 kg payload flew from Fort Sumner, New Mexico in early September 2006 and was a great success. In 2007, students participated in the second HASP flight to measure the cosmic ray intensity and flux using a traditional film and absorber stack with five layers of optically stimulated luminescent (OSL) dosimeters. Results from both payloads showed that the cosmic ray flux decreases as a function of payload depth. As the cosmic rays go through the stack, they deposit their energy in the payload material. Determining cosmic ray flux is a tedious task. It involves digitizing the film and determining the real cosmic ray density. For the first HASP payload, students used a program known as GlobalLab to count particles. For the second payload, the students decided to use a combination of the GREYCStoration image regularization algorithm, an embossing filter, and a depth-merging filter to reconstruct the paths of the cosmic rays.
Neronov, Andrii
2017-11-10
Cosmic rays could be produced via shock acceleration powered by supernovae. The supernova hypothesis implies that each supernova injects, on average, some 10^{50} erg in cosmic rays, while the shock acceleration model predicts a power law cosmic ray spectrum with the slope close to 2. Verification of these predictions requires measurement of the spectrum and power of cosmic ray injection from supernova population(s). Here, we obtain such measurements based on γ-ray observation of the Constellation III region of the Large Magellanic Cloud. We show that γ-ray emission from this young star formation region originates from cosmic rays injected by approximately two thousand supernovae, rather than by a massive star wind powered by a superbubble predating supernova activity. Cosmic ray injection power is found to be (1.1_{-0.2}^{+0.5})×10^{50} erg/supernova (for the estimated interstellar medium density 0.3 cm^{-3}). The spectrum is a power law with slope 2.09_{-0.07}^{+0.06}. This agrees with the model of particle acceleration at supernova shocks and provides a direct proof of the supernova origin of cosmic rays.
The converter mechanism of particle acceleration and the maximum energy of cosmic rays
NASA Astrophysics Data System (ADS)
Kocharovsky, Vl. V.; Aharonian, F. A.; Derishev, E. V.; Kocharovsky, V. V.
We consider the fundamental limits on the energy of particles accelerated by electromagnetic forces in various astrophysical objects [1]. We show that accelerator's parameters are strongly limited not only by the particle confinement in large-scale magnetic field or by the difference in electric potentials (generalized Hillas criterion) but also by the curvature and other types of radiative losses of accelerated particles. Optimization of these requirements in terms of accelerator's size and the magnetic field strength results in the ultimate lower limit on the overall source energy budget, which scales as the fifth power of attainable particle energy. It is demonstrated that the curvature gamma-rays accompanying the acceleration gives further restrictions for potential acceleration sites. We compare different acceleration mechanisms and show, that the converter mechanism, which we suggested earlier [2], is the least sensitive to the geometry of the magnetic field in accelerators and allows to reach cosmic-ray energies close to the fundamental limit. The converter mechanism works most efficiently in relativistic shocks or shear flows. It utilizes multiple conversions of charged particles into neutral ones (protons to neutrons and electrons/positrons to photons) and back by means of photon-induced reactions or inelastic nucleon- nucleon collisions. We discuss the properties of gamma-ray radiation, which accompanies acceleration of cosmic rays via the converter mechanism and can provide an evidence for the latter. 1. F.A. Aharonian, A.A. Belyanin, E.V. Derishev, V.V. Kocharovsky, and Vl.V. Kocharovsky, Phys. Rev. D 66, 023005 (2002). 2. E.V. Derishev, F.A. Aharonian, V.V. Kocharovsky, and Vl.V. Kocharovsky, Phys. Rev. D 68, 043003 (2003).
Fielding, Lee A; Hillier, Jon K; Burchell, Mark J; Armes, Steven P
2015-12-11
Over the last decade or so, a range of polypyrrole-based particles have been designed and evaluated for space science applications. This electrically conductive polymer enables such particles to efficiently acquire surface charge, which in turn allows their acceleration up to the hypervelocity regime (>1 km s(-1)) using a Van de Graaff accelerator. Either organic latex (e.g. polystyrene or poly(methyl methacrylate)) or various inorganic materials (such as silica, olivine or pyrrhotite) can be coated with polypyrrole; these core-shell particles are useful mimics for understanding the hypervelocity impact ionisation behaviour of micro-meteorites (a.k.a. cosmic dust). Impacts on metal targets at relatively low hypervelocities (<10 km s(-1)) generate ionic plasma composed mainly of molecular fragments, whereas higher hypervelocities (>10 km s(-1)) generate predominately atomic species, since many more chemical bonds are cleaved if the particles impinge with higher kinetic energy. Such fundamental studies are relevant to the calibration of the cosmic dust analyser (CDA) onboard the Cassini spacecraft, which was designed to determine the chemical composition of Saturn's dust rings. Inspired by volcanism observed for one of the Jupiter's moons (Io), polypyrrole-coated sulfur-rich latexes have also been designed to help space scientists understand ionisation spectra originating from sulfur-rich dust particles. Finally, relatively large (20 μm diameter) polypyrrole-coated polystyrene latexes have proven to be useful for understanding the extent of thermal ablation of organic projectiles when fired at ultralow density aerogel targets at up to 6.1 km s(-1) using a Light Gas Gun. In this case, the sacrificial polypyrrole overlayer simply provides a sensitive spectroscopic signature (rather than a conductive overlayer), and the scientific findings have important implications for the detection of organic dust grains during the Stardust space mission.
NASA Astrophysics Data System (ADS)
Case, A. W.; Kasper, J. C.; Spence, H. E.; Golightly, M. J.; Schwadron, N. A.; Mazur, J. E.; Blake, J. B.; Looper, M. D.; Townsend, L.; Zeitlin, C. J.
2011-12-01
The Cosmic Ray Telescope for the Effects of Radiation is an energetic particle telescope that resides on the Lunar Reconnaissance Orbiter spacecraft, currently in a 50 km circular lunar polar orbit. The telescope consists of 6 silicon semi-conductor detectors placed in pairs that surround two pieces of Tissue Equivalent Plastic (TEP), which serve to absorb energy from particles as they transit through the instrument. Particles with energies greater than 12 MeV/nucleon can penetrate the outermost shield and be measured by the instrument. The primary measurement made by the instrument is of the Linear Energy Transfer (LET) of energetic particles as they transit through the telescope. CRaTER measures the LET spectrum with unprecedented energy resolution and has done so during a period of historically low solar activity that led to record high intensities of Galactic Cosmic Rays (GCR). These LET spectra are used to study changes in the properties of the incoming particles, and to make detailed measurements of the radiation doses human explorers will experience in deep space on missions to the moon, to asteroids, or to Mars. We present LET spectra accumulated during 2009 and 2010. We show how the LET spectrum evolves through the instrument as the GCR interact with the TEP. Due to the importance of these measurements for human effects, our extensive absolute calibration procedures are presented. Of particular note is a significant reduction in the flux of particles with LET greater than 10 keV/um for detectors that lie deeper within the telescope stack, due to the attenuation of high LET particles within the TEP. By measuring this attenuation we can estimate the depth in human tissue where the highest LET particles that are most likely to cause genetic damage pose the greatest threat to humans in space.
NASA Technical Reports Server (NTRS)
Weekes, Trevor C.
1998-01-01
There are few things more intriguing in high energy astrophysics than the study of the highest energy particles in the universe. Where and how these particles achieve their extreme energies is of interest not only to the astrophysicist but also to the particle physicist. At GeV and TeV energies the problem is manageable since the physics is known and the acceleration processes feasible. But the energy spectrum extends to 10(exp 20)Ev and there the problem of their origin is both more difficult and interesting; in fact at these high energies we do not even know what the particles are. The study of the origin and distribution of relativistic particles in the universe has been a challenge for more than 80 years but it is only in recent years that the technology has become available to really address the question. Although something can be learned from studies of composition and energy spectrum, the origins (and thence the acceleration mechanisms) can only come from the direct study of the neutral particle component (in this respect the highest energy particles are effectively neutral since they are virtually undeflected). The feasible channels of investigation are therefore the study of the arrival directions of: (1) TeV photons (covered by the following U.S. experiments: STACEE, Whipple/VERITAS, MILAGRO and, to some extent, by EGRET/GLAST); (2) neutrinos of TeV energy and above (AMANDA/KM3); (3) the highest energy cosmic rays (HiRes, Auger). While these studies represent a form of astronomy they are the astronomy of the extraordinary universe, the universe populated by the most dynamic and physically exciting objects, the universe of the high energy astrophysicist whose cosmic laboratories represent conditions beyond anything that can be duplicated in a terrestrial laboratory. This extraordinary astronomy may say little about the normal evolution of stars and galaxies but it opens windows into cosmic particle acceleration where new and strange physical processes take place.
PREFACE: 23rd European Cosmic Ray Symposium (and 32nd Russian Cosmic Ray Conference)
NASA Astrophysics Data System (ADS)
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) PCR-IIPrimary cosmic rays II (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 thank those very many colleagues and friends with whom I have had the pleasure of working over the past 45 years. These thanks are extended to the present organizers. The organizers are very grateful to the Russian Foundation of Basic Research and to the Dynasty non-profit foundation for financial support. Arnold Wolfendale
High-energy particle acceleration in the shell of a supernova remnant.
Aharonian, F A; Akhperjanian, A G; Aye, K-M; Bazer-Bachi, A R; Beilicke, M; Benbow, W; Berge, D; Berghaus, P; Bernlöhr, K; Bolz, O; Boisson, C; Borgmeier, C; Breitling, F; Brown, A M; Gordo, J Bussons; Chadwick, P M; Chitnis, V R; Chounet, L-M; Cornils, R; Costamante, L; Degrange, B; Djannati-Ataï, A; Drury, L O'C; Ergin, T; Espigat, P; Feinstein, F; Fleury, P; Fontaine, G; Funk, S; Gallant, Y A; Giebels, B; Gillessen, S; Goret, P; Guy, J; Hadjichristidis, C; Hauser, M; Heinzelmann, G; Henri, G; Hermann, G; Hinton, J A; Hofmann, W; Holleran, M; Horns, D; De Jager, O C; Jung, I; Khélifi, B; Komin, Nu; Konopelko, A; Latham, I J; Le Gallou, R; Lemoine, M; Lemière, A; Leroy, N; Lohse, T; Marcowith, A; Masterson, C; McComb, T J L; De Naurois, M; Nolan, S J; Noutsos, A; Orford, K J; Osborne, J L; Ouchrif, M; Panter, M; Pelletier, G; Pita, S; Pohl, M; Pühlhofer, G; Punch, M; Raubenheimer, B C; Raue, M; Raux, J; Rayner, S M; Redondo, I; Reimer, A; Reimer, O; Ripken, J; Rivoal, M; Rob, L; Rolland, L; Rowell, G; Sahakian, V; Saugé, L; Schlenker, S; Schlickeiser, R; Schuster, C; Schwanke, U; Siewert, M; Sol, H; Steenkamp, R; Stegmann, C; Tavernet, J-P; Théoret, C G; Tluczykont, M; Van Der Walt, D J; Vasileiadis, G; Vincent, P; Visser, B; Völk, H J; Wagner, S J
2004-11-04
A significant fraction of the energy density of the interstellar medium is in the form of high-energy charged particles (cosmic rays). The origin of these particles remains uncertain. Although it is generally accepted that the only sources capable of supplying the energy required to accelerate the bulk of Galactic cosmic rays are supernova explosions, and even though the mechanism of particle acceleration in expanding supernova remnant (SNR) shocks is thought to be well understood theoretically, unequivocal evidence for the production of high-energy particles in supernova shells has proven remarkably hard to find. Here we report on observations of the SNR RX J1713.7 - 3946 (G347.3 - 0.5), which was discovered by ROSAT in the X-ray spectrum and later claimed as a source of high-energy gamma-rays of TeV energies (1 TeV = 10(12) eV). We present a TeV gamma-ray image of the SNR: the spatially resolved remnant has a shell morphology similar to that seen in X-rays, which demonstrates that very-high-energy particles are accelerated there. The energy spectrum indicates efficient acceleration of charged particles to energies beyond 100 TeV, consistent with current ideas of particle acceleration in young SNR shocks.
NASA Astrophysics Data System (ADS)
Araujo, A. C.; Félix, J.
2016-10-01
In the study of cosmic rays, measurements of time of flight and momentum have been used to identify incident particles from its physical properties, like mass. In this poster we present the design, construction, characterization, and operation of a detector to measure time of flight of cosmic rays. The device is comprised of three plates of plastic scintillator arranged in vertical straight line, they are coupled to one photomultiplier tube. The analogical output has been connected to a data acquisition system to obtain the number of digital pulses per millisecond. We present preliminary results.
A New Measurement of the Cosmic-Ray Proton and Helium Spectra
NASA Astrophysics Data System (ADS)
Mocchiutti, E.; Ambriola, M.; Bartalucci, S.; Bellotti, R.; Bergström, D.; Boezio, M.; Bonicini, V.; Bravar, U.; Cafagna, F.; Carlson, P.; Casolino, M.; Ciacio, F.; Circella, M.; De Marzo, C. N.; De Pascale, M. P.; Finetti, N.; Francke, T.; Hansen, P.; Hof, M.; Kremer, J.; Menn, W.; Mitchell, J. W.; Mocchiutti, E.; Morselli, A.; Ormes, J. F.; Papini, P.; Piccardi, S.; Picozza, P.; Ricci, M.; Schiavon, P.; Simon, M.; Sparvoli, R.; Spillantini, P.; Stephens, S. A.; Stochaj, S. J.; Streitmatter, R. E.; Suffert, M.; Vacchi, A.; Vannuccini, E.; Zampa, N.; WIZARD/CAPRICE Collaboration
2001-08-01
A new measurement of the primary cosmic ray spectra was performed during the balloon-borne CAPRICE experiment in 1998. This apparatus consists of a magnet spectrometer, with a superconducting magnet and a driftchamber tracking device, a time of flight scintillator system, a silicon-tungsten imaging calorimeter and a gas ring imaging Cherenkov detector. This combination of state-of-the-art detectors provides excellent particle discrimination capabilities, such that detailed investigations of the antiproton, electron/positron, muon and primary components of cosmic rays have been performed. The analysis of the primary proton component is illustrated in this paper.
Launch in orbit of the telescope NINA for cosmic ray observations: preliminary results
NASA Astrophysics Data System (ADS)
Sparvoli, R.; Bidoli, V.; Canestro, A.; Casolino, M.; de Pascale, M. P.; Furano, G.; Iannucci, A.; Morselli, A.; Picozza, P.; Bakaldin, A.; Galper, A.; Koldashov, S.; Korotkov, M.; Leonov, A.; Mikhailov, V.; Murashov, A.; Voronov, S.; Bonvicini, V.; Cirami, R.; Vacchi, A.; Zampa, N.; Ambriola, M.; Bellotti, R.; Cafagna, F.; Ciacio, F.; Circella, M.; de Marzo, C.; Bartalucci, S.; Ricci, M.; Adriani, O.; Papini, P.; Piccardi, S.; Spillantini, P.; Boezio, M.; Castellini, G.
2000-05-01
On July the 10th, 1998 the telescope NINA was launched in space on board the Russian satellite Resurs-01 n.4. The scientific task of the mission is the study of the galactic, solar and anomalous components of the cosmic rays in the energy interval 10-200 MeV/n for contained particles. The core of NINA is a segmented silicon detector mounted onto the satellite so to point to the zenith.In this paper we report about the cosmic ray measurements performed by the telescope during its first 6 months of operation
Anisotropy of cosmic rays above 10(14) eV
NASA Technical Reports Server (NTRS)
Wdowczyk, J.; Wolfendale, A. W.
1985-01-01
A survey is made of the anisotropy of cosmic rays at energies above 10 to the 14th power eV. It is concluded that cosmic gamma-rays may have an effect in the range 10 to the 14 power - 10 to the 16th power eV, above which protons dominate. Evidence is presented for an excess in the general direction of the Galactic plane which grows with increasing energy until about 10 to the 19th power eV, indicating a Galactic origin for these particles. At higher energies an Extragalactic origin is indicated.
The Origin of Cosmic Rays: What can GLAST Say?
NASA Technical Reports Server (NTRS)
Ormes, Jonathan F.; Digel, Seith; Moskalenko, Igor V.; Moiseev, Alexander; Williamson, Roger
2000-01-01
Gamma rays in the band from 30 MeV to 300 GeV, used in combination with direct measurements and with data from radio and X-ray bands, provide a powerful tool for studying the origin of Galactic cosmic rays. Gamma-ray Large Area Space Telescope (GLAST) with its fine 10-20 arcmin angular resolution will be able to map the sites of acceleration of cosmic rays and their interactions with interstellar matter, It will provide information that is necessary to study the acceleration of energetic particles in supernova shocks, their transport in the interstellar medium and penetration into molecular clouds.
COSMIC-RAY PITCH-ANGLE SCATTERING IN IMBALANCED MHD TURBULENCE SIMULATIONS
DOE Office of Scientific and Technical Information (OSTI.GOV)
Weidl, Martin S.; Jenko, Frank; Teaca, Bogdan
2015-09-20
Pitch-angle scattering rates for cosmic-ray particles in MHD simulations with imbalanced turbulence are calculated for fully evolving electromagnetic turbulence. We compare with theoretical predictions derived from the quasilinear theory of cosmic-ray diffusion for an idealized slab spectrum and demonstrate how cross helicity affects the shape of the pitch-angle diffusion coefficient. Additional simulations in evolving magnetic fields or static field configurations provide evidence that the scattering anisotropy in imbalanced turbulence is not primarily due to coherence with propagating Alfvén waves, but an effect of the spatial structure of electric fields in cross-helical MHD turbulence.
Cosmic Ray Acceleration from Multiple Galactic Wind Shocks
NASA Astrophysics Data System (ADS)
Cotter, Cory; Bustard, Chad; Zweibel, Ellen
2018-01-01
Cosmic rays still have an unknown origin. Many mechanisms have been suggested for their acceleration including quasars, pulsars, magnetars, supernovae, supernova remnants, and galactic termination shocks. The source of acceleration may be a mixture of these and a different mixture in different energy regimes. Using numerical simulations, we investigate multiple shocks in galactic winds as potential cosmic rays sources. By having shocks closer to the parent galaxy, more particles may diffuse back to the disk instead of being blown out in the wind, as found in Bustard, Zweibel, and Cotter (2017, ApJ) and also Merten, Bustard, Zweibel, and Tjus (to be submitted to ApJ). Specifically, this flux of cosmic rays could contribute to the unexplained "shin" region between the well-known "knee" and "ankle" of the cosmic ray spectrum. We would like to acknowledge support from the National Science Foundation (NSF) Graduate Research Fellowship Program under grant No. DGE-125625 and NSF grant No. AST-1616037.
Cosmic ray physics in space: the role of Sergey Vernov's scientific school
NASA Astrophysics Data System (ADS)
Panasyuk, M. I.
2011-04-01
Cosmic rays were discovered almost 100 years ago. Since then the scientific world has learned a lot from their nature: the particles nascent in the Universe, both in our Galaxy and outside, the basic mechanisms of their acceleration, transfer in the interstellar environment and the interaction of the primary cosmic rays with the atmosphere surrounding the Earth. Before 1957, i.e., the beginning of the Space Era, researchers' capabilities were limited to experiments performed on the ground, underground and in near-ground atmosphere to flight altitudes of aerostats, airplanes and rockets, i.e., where only secondary radiation is in existence, this is the result of the interaction of cosmic rays with the Earth's atmosphere. The launching of spacecraft allowed the scientists to commence exploring the Universe's primordial matter itself outside the atmosphere, i.e., the primary cosmic rays. Sergey Vernov, the Russian scientist, was among them.
The evolution of cosmic-ray-mediated magnetohydrodynamic shocks: A two-fluid approach
NASA Astrophysics Data System (ADS)
Jun, Byung-Il; Clarke, David A.; Norman, Michael L.
1994-07-01
We study the shock structure and acceleration efficiency of cosmic-ray mediated Magnetohydrodynamic (MHD) shocks both analytically and numerically by using a two-fluid model. Our model includes the dynamical effect of magnetic fields and cosmic rays on a background thermal fluid. The steady state solution is derived by following the technique of Drury & Voelk (1981) and compared to numerical results. We explore the time evolution of plane-perpendicular, piston-driven shocks. From the results of analytical and numerical studies, we conclude that the mean magnetic field plays an important role in the structure and acceleration efficiency of cosmic-ray mediated MHD shocks. The acceleration of cosmic-ray particles becomes less efficient in the presence of strong magnetic pressure since the field makes the shock less compressive. This feature is more prominent at low Mach numbers than at high Mach numbers.
The evolution of cosmic-ray-mediated magnetohydrodynamic shocks: A two-fluid approach
NASA Technical Reports Server (NTRS)
Jun, Byung-Il; Clarke, David A.; Norman, Michael L.
1994-01-01
We study the shock structure and acceleration efficiency of cosmic-ray mediated Magnetohydrodynamic (MHD) shocks both analytically and numerically by using a two-fluid model. Our model includes the dynamical effect of magnetic fields and cosmic rays on a background thermal fluid. The steady state solution is derived by following the technique of Drury & Voelk (1981) and compared to numerical results. We explore the time evolution of plane-perpendicular, piston-driven shocks. From the results of analytical and numerical studies, we conclude that the mean magnetic field plays an important role in the structure and acceleration efficiency of cosmic-ray mediated MHD shocks. The acceleration of cosmic-ray particles becomes less efficient in the presence of strong magnetic pressure since the field makes the shock less compressive. This feature is more prominent at low Mach numbers than at high Mach numbers.
Big Bang Day : The Great Big Particle Adventure - 2. Who Ordered That?
None
2017-12-09
In this series, comedian and physicist Ben Miller asks the CERN scientists what they hope to find. The atoms that make up our material world are important to us, but it turns out they aren't so significant on the cosmic stage. In fact early in the search for the stuff of atoms, researchers discovered particles that played no part in Earthly chemistry - for example particles in cosmic rays that resemble electrons (the stuff of electricity and the chemical glue in molecules) in almost all respects except that they weigh 140 times more. "Who ordered that?" one Nobel laureate demanded. They also discovered antimatter - the destructive mirror-image particles at obliterate all matter they come into contact with. In fact, the Universe is mostly made up of particles that could never make atoms, so that we are just the flotsam of the cosmos. But the main constituent of the Universe, what makes 80% of creation, has never been seen in the lab. Researchers at CERN believe they can create samples of it, down here on Earth.
Detailed numerical investigation of the Bohm limit in cosmic ray diffusion theory
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hussein, M.; Shalchi, A., E-mail: m_hussein@physics.umanitoba.ca, E-mail: andreasm4@yahoo.com
2014-04-10
A standard model in cosmic ray diffusion theory is the so-called Bohm limit in which the particle mean free path is assumed to be equal to the Larmor radius. This type of diffusion is often employed to model the propagation and acceleration of energetic particles. However, recent analytical and numerical work has shown that standard Bohm diffusion is not realistic. In the present paper, we perform test-particle simulations to explore particle diffusion in the strong turbulence limit in which the wave field is much stronger than the mean magnetic field. We show that there is indeed a lower limit ofmore » the particle mean free path along the mean field. In this limit, the mean free path is directly proportional to the unperturbed Larmor radius like in the traditional Bohm limit, but it is reduced by the factor δB/B {sub 0} where B {sub 0} is the mean field and δB the turbulent field. Although we focus on parallel diffusion, we also explore diffusion across the mean field in the strong turbulence limit.« less
NASA Astrophysics Data System (ADS)
Matthiä, Daniel; Hassler, Donald M.; de Wet, Wouter; Ehresmann, Bent; Firan, Ana; Flores-McLaughlin, John; Guo, Jingnan; Heilbronn, Lawrence H.; Lee, Kerry; Ratliff, Hunter; Rios, Ryan R.; Slaba, Tony C.; Smith, Michael; Stoffle, Nicholas N.; Townsend, Lawrence W.; Berger, Thomas; Reitz, Günther; Wimmer-Schweingruber, Robert F.; Zeitlin, Cary
2017-08-01
The radiation environment at the Martian surface is, apart from occasional solar energetic particle events, dominated by galactic cosmic radiation, secondary particles produced in their interaction with the Martian atmosphere and albedo particles from the Martian regolith. The highly energetic primary cosmic radiation consists mainly of fully ionized nuclei creating a complex radiation field at the Martian surface. This complex field, its formation and its potential health risk posed to astronauts on future manned missions to Mars can only be fully understood using a combination of measurements and model calculations. In this work the outcome of a workshop held in June 2016 in Boulder, CO, USA is presented: experimental results from the Radiation Assessment Detector of the Mars Science Laboratory are compared to model results from GEANT4, HETC-HEDS, HZETRN, MCNP6, and PHITS. Charged and neutral particle spectra and dose rates measured between 15 November 2015 and 15 January 2016 and model results calculated for this time period are investigated.
NASA Technical Reports Server (NTRS)
Dibenedetto, F.
1973-01-01
By application of Lyttleton's theory for the formation of comets, it is shown that a possible mechanism for the origin and formation of a concentration of cosmic particles around the earth and the other planets of the solar system exists. In the vicinity of the neutral point, where the velocity of colliding particles is not greater than 6 km/s, it is found that if the solid particles after collision must remain in a solid state, there can be no possibility of accretion for Mercury, Mars, and the Moon, where the maximum value of the distance of the center of the planet to the asymptotic trajectory is less than the radius of the planet. On the other hand, the capture radii of microparticles in solid form varies from a minimum of 2.95 planetary radii for Venus and 3.47 for the Earth, to about 986 for Jupiter.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dieckmann, M.E.; Shukla, P.K.; Eliasson, B.
2006-06-15
The ever increasing performance of supercomputers is now enabling kinetic simulations of extreme astrophysical and laser produced plasmas. Three-dimensional particle-in-cell (PIC) simulations of relativistic shocks have revealed highly filamented spatial structures and their ability to accelerate particles to ultrarelativistic speeds. However, these PIC simulations have not yet revealed mechanisms that could produce particles with tera-electron volt energies and beyond. In this work, PIC simulations in one dimension (1D) of the foreshock region of an internal shock in a gamma ray burst are performed to address this issue. The large spatiotemporal range accessible to a 1D simulation enables the self-consistent evolutionmore » of proton phase space structures that can accelerate particles to giga-electron volt energies in the jet frame of reference, and to tens of tera-electron volt in the Earth's frame of reference. One potential source of ultrahigh energy cosmic rays may thus be the thermalization of relativistically moving plasma.« less
NASA Technical Reports Server (NTRS)
Sisterson, J. M.; Jones, D. T. L.; Binns, P. J.; Langen, K.; Schroeder, I.; Buthelezi, Z.; Latti, E.; Brooks, F. D.; Buffler, A.; Allie, M. S.;
2001-01-01
Cross section measurements for neutron-induced reactions are summarized. Measured cross sections for 22 Na produced by neutrons in Al and Si are used to calculate the production rate for 22 Na in lunar rock 12002 by galactic cosmic ray particles. Additional information is contained in the original extended abstract.
Galactic cosmic ray composition
NASA Technical Reports Server (NTRS)
Meyer, J. P.
1986-01-01
An assessment is given of the galactic cosmic ray source (GCRS) elemental composition and its correlation with first ionization potential. The isotopic composition of heavy nuclei; spallation cross sections; energy spectra of primary nuclei; electrons; positrons; local galactic reference abundances; comparison of solar energetic particles and solar coronal compositions; the hydrogen; lead; nitrogen; helium; and germanium deficiency problems; and the excess of elements are among the topics covered.
COSMIC RAYS AND COSMIC SPACE (in Russian)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Vernova, S.N.
1960-08-01
An account is given of recent studies of cosmic rays utilizing both earthbound stations and artificial earth satellites. Phenomena recently uncovered by sputniks are described. A description is given of the cosmic ray laboratory of Moscow University. A particle possessing an energy of l0/sup 15/ ev was detected and the equipment and procedure by which this was done are described. mu mesons in a particle shower produced by cosmic rays were detected at a depth of thirty meters underground. The apparatus required in the sputriks for the study of cosmic rays outside the earth's atmosphere is discussed. The equipment inmore » the sputniks launched to date was transistorized; scintillation counters were used to determine particle energies. A description is given of the large burst of radiation detected by the second sputnik on Nov. 7, 1957. This burst was observed only at latitudes of about 50 to 70 degrees north latitude. The third sputnik had a scintillation counter of high sensitivity which detected relatively weak fluxes of electrons. This equipment fixed the location of the high intensity radiation belt around the earth. A typical graph of count rate and energy current versus geographic location is given. Data are given that indicate the coincidence of peak radiation intensities with those regions where the aurora borealis is seen. The radiation belt extends up to approximately 60,000 km from the earth's surface and is bounded by the magnetic lines of force that intersect the earth' s surface at geomagnetic latitudes of 55 deg and 70 deg . The earth's magnetic field traps these particles and holds them in an orbit that follows magnetic lines of force and oscillates from the northern to the southern hemisphere for long periods of time. A diagram is given of the trajectory of the first Soviet cosmic rocket and changes in radiation intensity along this trajectory are indicated. A maximum radiation intensity was detected at a distance of 20,000 km from the earth's surface. A diagram compares the data of the first and second Soviet cosmic rockets. It is indicated that radiation intensity in the outer belt varies with time due to variation of emanations from the sun. The energy spectrum of radiation in the outer belt was obtained with gas discharge and scintillation counters installed behind varying amounts of lead, copper, and aluminum shielding. Results are given in a diagram of particle and energy flux versus distance from the earth. The conclusion is reached that the outer radiation belt consists of electrons whose energies vary over six orders of magnitude. However the data from the second rocket indicated that the upper limit of electron energies appears to be 5 Mev. The electron flux is highest at an energy of about 1 Mev. It is pointed out that in the outer radiation belt the energy density of radiation approaches its maximum possible value, that is, the energy density of the earth's magnetic field at that distance. A discussion is given of the inner radiation belt, first described by Van Allen. No evidence of radiation belts about the moon was found. A discussion of the possible origins of the outer radiation belt of the earth and of other radiation belts and magnetic fields in space is given. In the study of solar flares, 1500 radiosonde balloon flights were made during the IGY. These flights established that solar flares are an extreme hazard for space travelers. (TTT)« less
Cosmic ray spectrum and composition from three years of IceTop and IceCube
NASA Astrophysics Data System (ADS)
Rawlins, K.;
2016-05-01
IceTop is the surface component of the IceCube Observatory, composed of frozen water tanks at the top of IceCube’s strings. Data from this detector can be analyzed in different ways with the goal of measuring cosmic ray spectrum and composition. The shower size S125 from IceTop alone can be used as a proxy for primary energy, and unfolded into an all-particle spectrum. In addition, S125 from the surface can be combined with high-energy muon energy loss information from the deep IceCube detector for those air showers which pass through both. Using these coincident events in a complementary analysis, both the spectrum and mass composition of primary cosmic rays can be extracted in parallel using a neural network. Both of these analyses have been performed on three years of IceTop and IceCube data. Both all-particle spectra as well as individual spectra for elemental groups are presented.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bernardo, Giuseppe Di; Evoli, Carmelo; Gaggero, Daniele
2013-03-01
A multichannel analysis of cosmic ray electron and positron spectra and of the diffuse synchrotron emission of the Galaxy is performed by using the DRAGON code. This study is aimed at probing the interstellar electron source spectrum down to E ∼< 1GeV and at constraining several propagation parameters. We find that above 4GeV the e{sup −} source spectrum is compatible with a power-law of index ∼ 2.5. Below 4GeV instead it must be significantly suppressed and the total lepton spectrum is dominated by secondary particles. The positron spectrum and fraction measured below a few GeV are consistently reproduced only withinmore » low reacceleration models. We also constrain the scale-height z{sub t} of the cosmic-ray distribution using three independent (and, in two cases, original) arguments, showing that values of z{sub t} ∼< 2kpc are excluded. This result may have strong implications for particle dark matter searches.« less
NASA Astrophysics Data System (ADS)
Khaerdinov, N. S.; Lidvansky, A. S.; Petkov, V. B.
2005-07-01
We present the data on correlations of the intensity of the soft component of cosmic rays with the local electric field of the near-earth atmosphere during thunderstorm periods at the Baksan Valley (North Caucasus, 1700 m a.s.l.). The large-area array for studying the extensive air showers of cosmic rays is used as a particle detector. An electric field meter of the 'electric mill' type (rain-protected) is mounted on the roof of the building in the center of this array. The data were obtained in the summer seasons of 2000-2002. We observe strong enhancements of the soft component intensity before some lightning strokes. At the same time, the analysis of the regression curve 'intensity versus field' discovers a bump at the field sign that is opposite to the field sign corresponding to acceleration of electrons. It is interpreted as a signature of runaway electrons from the region of the strong field (with opposite sign) overhead.
Los Alamos, Toshiba probing Fukushima with cosmic rays
DOE Office of Scientific and Technical Information (OSTI.GOV)
Morris, Christopher
2014-06-16
Los Alamos National Laboratory has announced an impending partnership with Toshiba Corporation to use a Los Alamos technique called muon tomography to safely peer inside the cores of the Fukushima Daiichi reactors and create high-resolution images of the damaged nuclear material inside without ever breaching the cores themselves. The initiative could reduce the time required to clean up the disabled complex by at least a decade and greatly reduce radiation exposure to personnel working at the plant. Muon radiography (also called cosmic-ray radiography) uses secondary particles generated when cosmic rays collide with upper regions of Earth's atmosphere to create imagesmore » of the objects that the particles, called muons, penetrate. The process is analogous to an X-ray image, except muons are produced naturally and do not damage the materials they contact. Muon radiography has been used before in imaginative applications such as mapping the interior of the Great Pyramid at Giza, but Los Alamos's muon tomography technique represents a vast improvement over earlier technology.« less
The dependence of solar modulation on the sign of the cosmic ray particle charge
NASA Technical Reports Server (NTRS)
Garcia-Munoz, M.; Meyer, P.; Pyle, K. R.; Simpson, J. A.; Evenson, P. A.
1985-01-01
The solar modulation of galactic cosmic ray helium and electrons at 1 AU, within the 600-1000 MV magnetic rigidity interval, are compared for the period from 1965 through 1984. The time-intensity variations during the two solar maxima around 1970 and 1981 show that after 1970 the helium intensity recovers earlier than that of the electrons, whereas after 1981 the electron intensity recovers earlier than that of helium. The flux ratio of helium to electrons (He/e) undergoes a major increases during the 1969-1971 period and a major decrease during 1979-83. These experimental results can be interpreted as due to a dependence of the solar modulation of galactic cosmic rays on the sign of the particle charge, possibly as a consequence of drifts due to gradients and curvatures in the interplanetary magnetic field. However, the comparison of the shapes of the intensity-time curves of helium and electrons in the period 1970-1981 does not support a major specific prediction of the drift model.
NASA Astrophysics Data System (ADS)
Minasyants, G. S.; Minasyants, T. M.; Tomozov, V. M.
2016-03-01
The accelerated particle energy spectra in different energy intervals (from 0.06 to 75.69 MeV n-1) have been constructed for various powerful flare events (1997-2006) with the appearance of solar cosmic rays (SCRs) based on the processing of data from the Advanced Composition Explorer (ACE) and WIND spacecraft. Flares were as a rule accompanied by coronal mass ejections. Different specific features in the particle spectra behavior, possibly those related to different acceleration processes, were revealed when the events developed. The Fe/O abundance ratio in different energy intervals during the disturbed development of flareinduced fluxes has been qualitatively estimated. It has been established that ground level event (GLE) fluxes represent an individual subclass of gradual events according to the character of Fe/O variations. The manifestations of the first ionization potential (FIP) effect in the composition of SCRs during their propagation have been qualitatively described.
Generation of mesoscale magnetic fields and the dynamics of Cosmic Ray acceleration
NASA Astrophysics Data System (ADS)
Diamond, P. H.; Malkov, M. A.
The problem of the cosmic ray origin is discussed in connection with their acceleration in supernova remnant shocks. The diffusive shock acceleration mechanism is reviewed and its potential to accelerate particles to the maximum energy of (presumably) galactic cosmic rays (1018eV ) is considered. It is argued that to reach such energies, a strong magnetic field at scales larger than the particle gyroradius must be created as a result of the acceleration process, itself. One specific mechanism suggested here is based on the generation of Alfven wave at the gyroradius scale with a subsequent transfer to longer scales via interaction with strong acoustic turbulence in the shock precursor. The acoustic turbulence in turn, may be generated by Drury instability or by parametric instability of the Alfven waves. The generation mechanism is modulational instability of CR generated Alfven wave packets induced, in turn, by scattering off acoustic fluctuations in the shock precursor which are generated by Drury instability.
Los Alamos, Toshiba probing Fukushima with cosmic rays
Morris, Christopher
2018-01-16
Los Alamos National Laboratory has announced an impending partnership with Toshiba Corporation to use a Los Alamos technique called muon tomography to safely peer inside the cores of the Fukushima Daiichi reactors and create high-resolution images of the damaged nuclear material inside without ever breaching the cores themselves. The initiative could reduce the time required to clean up the disabled complex by at least a decade and greatly reduce radiation exposure to personnel working at the plant. Muon radiography (also called cosmic-ray radiography) uses secondary particles generated when cosmic rays collide with upper regions of Earth's atmosphere to create images of the objects that the particles, called muons, penetrate. The process is analogous to an X-ray image, except muons are produced naturally and do not damage the materials they contact. Muon radiography has been used before in imaginative applications such as mapping the interior of the Great Pyramid at Giza, but Los Alamos's muon tomography technique represents a vast improvement over earlier technology.
Effects of Cutoffs on Galactic Cosmic-Ray Interactions in Solar-System Matter
NASA Technical Reports Server (NTRS)
Kim, K. J.; Reedy, R. C.; Masarik, J.
2005-01-01
The energetic particles in the galactic cosmic rays (GCR) induce many interactions in a variety of solar-system matter. Cosmogenic nuclides are used to study the histories of meteorites and lunar samples. Gamma rays and neutrons are used to map the compositions of planetary surfaces, such as Mars, the Moon, and asteroids. In almost all of these cases, the spectra of incident GCR particles are fairly similar, with only some modulation by the Sun over an 11-year cycle. Strong magnetic fields can seriously affect the energy spectrum of GCR particles hitting the surface of objects inside the magnetic fields. The Earth s geomagnetic field is strong enough that only GCR particles with magnetic rigidities above approx. 17 GV (a proton energy of approx. 17 GeV) reach the atmosphere over certain regions near the equator. This effect of removing lower-energy GCR particles is called a cutoff. The jovian magnetic fields are so strong that the fluxes of GCR particles hitting the 4 large Galilean satellites are similarly affected. The cutoff at Europa is estimated to be similar to or a little higher than at the Earth s equator.
NASA Astrophysics Data System (ADS)
Villar, Xabier; Piso, Daniel; Bruguera, Javier D.
2014-02-01
This paper presents an FPGA implementation of an algorithm, previously published, for the the reconstruction of cosmic rays' trajectories and the determination of the time of arrival and velocity of the particles. The accuracy and precision issues of the algorithm have been analyzed to propose a suitable implementation. Thus, a 32-bit fixed-point format has been used for the representation of the data values. Moreover, the dependencies among the different operations have been taken into account to obtain a highly parallel and efficient hardware implementation. The final hardware architecture requires 18 cycles to process every particle, and has been exhaustively simulated to validate all the design decisions. The architecture has been mapped over different commercial FPGAs, with a frequency of operation ranging from 300 MHz to 1.3 GHz, depending on the FPGA being used. Consequently, the number of particle trajectories processed per second is between 16 million and 72 million. The high number of particle trajectories calculated per second shows that the proposed FPGA implementation might be used also in high rate environments such as those found in particle and nuclear physics experiments.
NASA Technical Reports Server (NTRS)
Zhang, Ming
2005-01-01
The primary goal of this project was to perform theoretical calculations of propagation of cosmic rays and energetic particles in 3-dimensional heliospheric magnetic fields. We used Markov stochastic process simulation to achieve to this goal. We developed computation software that can be used to study particle propagation in, as two examples of heliospheric magnetic fields that have to be treated in 3 dimensions, a heliospheric magnetic field suggested by Fisk (1996) and a global heliosphere including the region beyond the termination shock. The results from our model calculations were compared with particle measurements from Ulysses, Earth-based spacecraft such as IMP-8, WIND and ACE, Voyagers and Pioneers in outer heliosphere for tests of the magnetic field models. We particularly looked for features of particle variations that can allow us to significantly distinguish the Fisk magnetic field from the conventional Parker spiral field. The computer code will eventually lead to a new generation of integrated software for solving complicated problems of particle acceleration, propagation and modulation in realistic 3-dimensional heliosphere of realistic magnetic fields and the solar wind with a single computation approach.
Measurements of primary cosmic-ray hydrogen and helium by the WiZard collaboration
NASA Astrophysics Data System (ADS)
Circella, M.; Ambriola, M.; Barbiellini, G.; Bartalucci, S.; Bellotti, R.; Bergström, D.; Bidoli, V.; Boezio, M.; Bonvicini, V.; Bravar, U.; Cafagna, F.; Carlson, P.; Casolino, M.; Ciacio, F.; Circella, M.; De Marzo, C.; De Pascale, M. P.; Finetti, N.; Francke, T.; Grimani, C.; Grinstein, S.; Hof, M.; Kremer, J.; Menn, W.; Mitchell, J. W.; Morselli, A.; Ormes, J. F.; Papini, P.; Piccardi, S.; Picozza, P.; Ricci, M.; Schiavon, P.; Simon, M.; Sparvoli, R.; Spillantini, P.; Stephens, S. A.; Stochaj, S. J.; Streitmatter, R. E.; Suffert, M.; Vacchi, A.; Weber, N.; Zampa, N.
We present the measurements of primary protons and helium nuclei performed by the WiZard Collaboration in different balloon-borne campaigns. A superconducting magnet spectrometer was used in these experiments together with detectors for particle recognition. These combinations of detectors made it possible to perform accurate particle measurements over a large (up to 200 GV for protons) energy interval. We focus in particular on the results from the MASS91 and CAPRICE94 experiments: We find a very good agreement between these two sets of measurements, also in comparison to other recent results. All these results seem to suggest that the normalization of primary cosmic rays may be significantly lower than previously estimated.
Direct energy inputs to the middle atmosphere
NASA Technical Reports Server (NTRS)
Rosenberg, T. J.; Lanzerotti, L. J.
1979-01-01
As a working definition of the extent of the middle atmosphere (MA), the height range from 30 to 100 km was adopted. The neutral and ionic composition and the dynamics within this height range are, for the most part, poorly understood. From available information, the importance of various particle and photon energy sources, including their variability, for ionization of the neutral atmosphere in this height range is assessed. The following topics are discussed: (1) penetration of the MA by particle and electromagnetic energy; (2) ionization sources for the MA; (3) galactic cosmic rays; (4) solar H Ly alpha, other EUV, and X-rays; (5) magnetospheric electrons and bremsstrahlung X-rays; and (6) solar cosmic rays.
A new component of cosmic rays of unknown origin at a few MeV per nucleon
NASA Technical Reports Server (NTRS)
Gloecker, G.
1974-01-01
Recently discovered anomalies in the abundances and energy spectra of quiet time, extraterrestrial hydrogen, helium, carbon, nitrogen, and oxygen require serious revisions of origin theories to account for this new component of cosmic radiation. Abnormally large O/C and N/C ratios, long term intensity variations with time, and radial gradient measurements indicate a non-solar origin for these 2 to 30 MeV/nucleon particles. Ideas suggested to explain these measurements range from acceleration of galactic source material having an unusual composition to local acceleration of particles within the solar cavity. Observations are at present insufficient to choose between these alternate origin models.
NASA Astrophysics Data System (ADS)
Barthel, Joseph; Sarigul-Klijn, Nesrin
2018-03-01
Deep space missions such as the planned 2025 mission to asteroids require spacecraft shields to protect electronics and humans from adverse effects caused by the space radiation environment, primarily Galactic Cosmic Rays. This paper first reviews the theory on how these rays of charged particles interact with matter, and then presents a simulation for a 500 day Mars flyby mission using a deterministic based computer code. High density polyethylene and aluminum shielding materials at a solar minimum are considered. Plots of effective dose with varying shield depth, charged particle flux, and dose in silicon and human tissue behind shielding are presented.
Detecting dark matter in the Milky Way with cosmic and gamma radiation
NASA Astrophysics Data System (ADS)
Carlson, Eric C.
Over the last decade, experiments in high-energy astroparticle physics have reached unprecedented precision and sensitivity which span the electromagnetic and cosmic-ray spectra. These advances have opened a new window onto the universe for which little was previously known. Such dramatic increases in sensitivity lead naturally to claims of excess emission, which call for either revised astrophysical models or the existence of exotic new sources such as particle dark matter. Here we stand firmly with Occam, sharpening his razor by (i) developing new techniques for discriminating astrophysical signatures from those of dark matter, and (ii) by developing detailed foreground models which can explain excess signals and shed light on the underlying astrophysical processes at hand. We concentrate most directly on observations of Galactic gamma and cosmic rays, factoring the discussion into three related parts which each contain significant advancements from our cumulative works. In Part I we introduce concepts which are fundamental to the Indirect Detection of particle dark matter, including motivations, targets, experiments, production of Standard Model particles, and a variety of statistical techniques. In Part II we introduce basic and advanced modelling techniques for propagation of cosmic-rays through the Galaxy and describe astrophysical gamma-ray production, as well as presenting state-of-the-art propagation models of the Milky Way.Finally, in Part III, we employ these models and techniques in order to study several indirect detection signals, including the Fermi GeV excess at the Galactic center, the Fermi 135 GeV line, the 3.5 keV line, and the WMAP-Planck haze.
time. It is usually measured in radians per second. Anisotropy- Physical property values that vary when negative charge. When an antimatter particle collides with its normal-matter counterpart, both particles neutrons. Big Bang- The violent cosmic explosion of an incredibly small amount of matter at high
NASA Astrophysics Data System (ADS)
Hoover, Stephen Lam Douglas
2010-11-01
New astronomical messengers may reveal unexpected aspects of the Universe and have often provided a unique source of fresh physical insights. Neutrinos are a promising new messenger particle, capable of carrying information from otherwise inaccessible sources. The ANtarctic Impulsive Transient Antenna (ANITA) seeks to make the first detection of an ultrahigh-energy (E > 1018 eV) neutrino flux. Such a neutrino flux almost certainly exists, produced in interactions of ultrahigh-energy cosmic rays with photons from the cosmic microwave background. ANITA is a balloon payload which monitors large volumes of the Antarctic ice sheet from an altitude of 38 km. An ultrahigh-energy neutrino which interacts in the ice sheet will produce a particle shower which will coherently radiate Cherenkov radiation in radio wavelengths (<3 GHz). Antennas on the balloon payload can then detect the resulting impulsive radio signal. The full ANITA flew for the first time from 15 December 2006 to 19 January 2007. In this dissertation, I will describe the ground calibration system used to transmit calibration signals to the payload in-flight. I will then describe techniques for analysis of ANITA data and give limits on the ultrahigh-energy neutrino flux implied by the null result of that analysis. Finally, I will demonstrate that ANITA is also sensitive to ultrahigh-energy cosmic rays and show the detection of 16 ultrahigh-energy cosmic-ray events during ANITA's first flight. This constitutes the highest frequency and widest bandwidth radio observations of cosmic-ray emission to date I show the average waveform and spectrum of these events and describe their polarization properties, which are strongly correlated with the geomagnetic field.
NASA Astrophysics Data System (ADS)
Mekhaldi, Florian; Muscheler, Raimund; Adolphi, Florian; Svensson, Anders; Aldahan, Ala; Possnert, Göran; McConnell, Joseph R.; Sigl, Michael; Welten, Kees C.; Woodruff, Thomas E.
2014-05-01
Miyake et al. (2012, 2013) discovered rapid increases of 14C content in tree rings dated to AD 774-5 and AD 993-4 which they have attributed to cosmic-ray events. These extreme particle events have no counterparts in the instrumental record and have been tentatively associated with solar proton events, supernovae and short gamma-ray bursts, which have very different energy spectra. Cosmogenic radionuclides such as 14C, 10Be and 36Cl arise from the interaction of cosmic rays with atmospheric nitrogen, oxygen and argon. These radio-isotopes are produced through different reaction pathways and vary with different energy dependencies of the production rate cross section. Owing to this, yield functions can be used to determine the energy level of incident particles. However, only 14C has been measured at high resolution to quantify the energy and thus the origin of the outbursts. We present an annually resolved record of 10Be from the NGRIP ice core for the two events. In addition, we also utilized the GRIP ice core 36Cl record in our analysis. Our results show that the differential production of cosmogenic 14C, 10Be and 36Cl is consistent with a solar energy spectrum. Considering the notable increase in radionuclides, the solar storms would have had to be substantially greater than the largest recorded geomagnetic storm, the so-called Carrington event. This challenges our understanding of the sun's dynamics. Furthermore, the events could possibly be of interest for the investigation of potential cosmic ray-cloud linkages (Svensmark & Friis-Christensen, 1997). Alternatively, such outbursts of energetic particles have the potential to deplete atmospheric ozone and alter atmospheric circulation. Ultimately, the magnitude of such particle events draws attention to the perhaps underestimated potential of the sun to cause great damage to modern technologies. References Miyake, F., Masuda, K. & Nakamura, T. Another rapid event in the carbon-14 content of tree rings. Nature Communications 4:1748, DOI: 10.1038/ncomms2783 (2013). Miyake, F., Nagaya, K., Masuda, K. & Nakamura, T. A signature of cosmic-ray increase in AD 774-775 from tree rings in Japan. Nature 486, 240-242, DOI: 210.1038/nature11123 (2012). Svensmark, H., & Friis-Christensen, E. Variation of cosmic ray flux and global cloud coverage - A missing link in solar-climate relationships. J. Atmos. Sol., Terr. Phys., 59, 225-1232, DOI: 10.1029/1998JD200091 (1997).
Fundamentals of Aerospace Medicine: Cosmic Radiation
NASA Technical Reports Server (NTRS)
Bagshaw, Michael; Cucionotta, Francis A.
2007-01-01
Cosmic rays were discovered in 1911 by the Austrian physicist, Victor Hess. The planet earth is continuously bathed in high-energy galactic cosmic ionizing radiation (GCR), emanating from outside the solar system, and sporadically exposed to bursts of energetic particles from the sun referred to as solar particle events (SPEs). The main source of GCR is believed to be supernovae (exploding stars), while occasionally a disturbance in the sun's atmosphere (solar flare or coronal mass ejection) leads to a surge of radiation particles with sufficient energy to penetrate the earth's magnetic field and enter the atmosphere. The inhabitants of planet earth gain protection from the effects of cosmic radiation from the earth s magnetic field and the atmosphere, as well as from the sun's magnetic field and solar wind. These protective effects extend to the occupants of aircraft flying within the earth s atmosphere, although the effects can be complex for aircraft flying at high altitudes and high latitudes. Travellers in space do not have the benefit of this protection and are exposed to an ionizing radiation field very different in magnitude and quality from the exposure of individuals flying in commercial airliners. The higher amounts and distinct types of radiation qualities in space lead to a large need for understanding the biological effects of space radiation. It is recognized that although there are many overlaps between the aviation and the space environments, there are large differences in radiation dosimetry, risks and protection for airline crew members, passengers and astronauts. These differences impact the application of radiation protection principles of risk justification, limitation, and the principle of as low as reasonably achievable (ALARA). This chapter accordingly is divided into three major sections, the first dealing with the basic physics and health risks, the second with the commercial airline experience, and the third with the aspects of cosmic radiation appertaining to space travel including future considerations.
NASA Astrophysics Data System (ADS)
Wang, Kai; Liu, Ruo-Yu; Li, Zhuo; Dai, Zi-Gao
2017-03-01
Muon pairs can be produced in the annihilation of ultrahigh energy (UHE, E ≳1 018 eV ) photons with low energy cosmic background radiation in the intergalactic space, giving birth to neutrinos. Although the branching ratio of muon pair production is low, products of other channels, which are mainly electron/positron pairs, will probably transfer most of their energies into the new generated UHE photon in the subsequent interaction with the cosmic background radiation via Compton scattering in deep Klein-Nishina regime. The regeneration of these new UHE photons then provides a second chance to produce the muon pairs, enhancing the neutrino flux. We investigate the neutrino production in the propagation of UHE photons in the intergalactic space at different redshifts, considering various competing processes such as pair production, double pair production for UHE photons, and triplet production and synchrotron radiation for UHE electrons. Following the analytic method raised by Gould and Rephaeli, we firstly study the electromagnetic cascade initiated by an UHE photon, with paying particular attention to the leading particle in the cascade process. Regarding the least energetic outgoing particles as energy loss, we obtain the effective penetration length of the leading particle, as well as energy loss rate including the neutrino emission rate in the cascade process. Finally, we find that an extra component of UHE neutrinos will arise from the propagation of UHE cosmic rays due to the generated UHE photons and electron/positrons. However, the flux of this component is quite small, with a flux of at most 10% of that of the conventional cosmogenic neutrino at a few EeV, in the absence of a strong intergalactic magnetic field and a strong cosmic radio background. The precise contribution of extra component depends on several factors, e.g., cosmic radio background, intergalactic magnetic field, and the spectrum of proton, which are discussed in this work.
New look on the origin of cosmic rays
NASA Astrophysics Data System (ADS)
Istomin, Ya. N.
2017-06-01
From the analysis of the flux of high energy particles, E > 3 · 1018 eV, it is shown that the distribution of the power density of extragalactic rays over energy is of the power law, q̅(E) ∝ E-2.7, with the same index of 2.7 that has the distribution of Galactic cosmic rays before the so called `knee', E < 3 · 1015 eV. However, the average power of extragalactic sources, which is of ɛ ≃ 1043 erg s-1, exceeds by at least two orders the power emitted by the Galaxy in cosmic rays, assuming that the density of galaxies is estimated as Ng ≃ 1 Mpc-3. Considering that such power can be provided by relativistic jets from active galactic nuclei with the power ɛ ≃ 1045 - 1046 erg s-1, we estimate the density of extragalactic sources of cosmic rays as Ng ≃ 10-2 - 10-3 Mpc-3. Assuming the same nature of Galactic and extragalactic rays, we conclude that the Galactic rays were produced by a relativistic jet emitted from the Galactic center during the period of its activity in the past. The remnants of a bipolar jet are now observed in the form of bubbles of relativistic gas above and below the Galactic plane. The break, observed in the spectrum of Galactic rays (`knee'), is explained by fast escape of energetic particles, E > 3 · 1015 eV, from the Galaxy because of the dependence of the coefficient of diffusion of cosmic rays on energy, D∝E0.7. The obtained index of the density distribution of particles over energy, N(E)∝E-2.7-0.7/2=E-3.05, for E > 3 · 1015 eV agrees well with the observed one, N(E)∝E-3.1. The estimated time of the termination of the jet in the Galaxy is 4.2 · 104 years ago.
NASA Technical Reports Server (NTRS)
Potter, A. E. (Editor); Wilson, T. L. (Editor)
1990-01-01
The present conference on physics and astrophysics from a lunar base encompasses space physics, cosmic ray physics, neutrino physics, experiments in gravitation and general relativity, gravitational radiation physics, cosmic background radiation, particle astrophysics, surface physics, and the physics of gamma rays and X-rays. Specific issues addressed include space-plasma physics research at a lunar base, prospects for neutral particle imaging, the atmosphere as particle detector, medium- and high-energy neutrino physics from a lunar base, muons on the moon, a search for relic supernovae antineutrinos, and the use of clocks in satellites orbiting the moon to test general relativity. Also addressed are large X-ray-detector arrays for physics experiments on the moon, and the measurement of proton decay, arcsec-source locations, halo dark matter and elemental abundances above 10 exp 15 eV at a lunar base.
NASA Technical Reports Server (NTRS)
Ng, C. K.
1986-01-01
The purpose is to provide an overview of the contributions presented in sessions SH3, SH1.5, SH4.6 and SH4.7 of the 19th International Cosmic Ray Conference. These contributed papers indicate that steady progress continues to be made in both the observational and the theoretical aspects of the transport and acceleration of energetic charged particles in the heliosphere. Studies of solar and interplanetary particles have placed emphasis on particle directional distributions in relation to pitch-angle scattering and magnetic focusing, on the rigidity and spatial dependence of the mean free path, and on new propagation regimes in the inner and outer heliosphere. Coronal propagation appears in need of correlative multi-spacecraft studies in association with detailed observation of the flare process and coronal magnetic structures. Interplanetary acceleration has now gone into a consolidation phase, with theories being worked out in detail and checked against observation.
The detection of high charge cosmic ray nuclei. [by balloon-borne electronic particle telescope
NASA Technical Reports Server (NTRS)
Scarlett, W. R.; Freier, P. S.; Waddington, C. J.
1975-01-01
A large-area, light-weight electronic particle telescope was flown on a high altitude balloon in the summer of 1974 to study the heavy nuclei in the cosmic radiation. This telescope consisted of a double Cerenkov-double scintillator array composed of four 1.22 m diameter disk radiators mounted in light diffusion boxes, each looked at by multiple photomultipliers. The impact point of each particle on the scintillation radiators was determined by studying the relative signals observed by three equally spaced peripheral photomultipliers and one mounted at the center of the diffusion boxes. This telescope was flown in a configuration having a geometric factor of 0.45 sq m sr and observed some 5 x 10 to the 4 nuclei with Z exceeding 14 in a 11 hr exposure. The response and sensitivity of this telescope are discussed in detail.
NASA Technical Reports Server (NTRS)
Kimura, Yuki; Nuth, Joseph A., III; Tsukamota, Katsuo; Kaito, Chihiro
2010-01-01
Exothermic reactions during the annealing of laboratory synthesized amorphous magnesium-bearing silicate particles used as grain analogs of cosmic dust were detected by differential scanning calorimetry (DSC) in air. With infrared spectroscopy and transmission electron microscopy, we show that cosmic dust could possibly undergo fusion to larger particles, with oxidation of magnesium silicide and crystallization of forsterite as exothermic reactions in the early solar system. The reactions begin at approximately 425, approximately 625, and approximately 1000 K, respectively, and the reaction energies (enthalpies) are at least 727, 4151, and 160.22 J per gram, respectively. During the crystallization of forsterite particles, the spectral evolution of the 10 micrometer feature from amorphous to crystalline was observed to begin at lower temperature than the crystallization temperature of 1003 K. During spectral evolution at lower temperature, nucleation and/or the formation of nanocrystallites of forsterite at the surface of the grain analogs was observed.
Pair production in the gravitational field of a cosmic string
NASA Astrophysics Data System (ADS)
Harari, Diego D.; Skarzhinsky, Vladimir D.
1990-04-01
We show that many elementary particle physics processes, such as pair production by a high energy photon, that take place in Minkowski space only if a non-uniform external field provides for momentum non-conservation, do occur in the space-time around a straight cosmic string, even though the space is locally flat and there is no local gravitational potential. We exemplify this mechanism through the evaluation of the cross section per unit length of string for the decay of a massless scalar particle into a pair of massive particles. The cross sections for this kind of processes are typically small. Nevertheless, it is interesting to realize how these reactions occur due to topological properties of space, rather than to the action of a local field. V.S. is grateful to Mario Castagnino for hospitality at the Instituto de Astronomía y Física del Espacio during a visit while this work was done.
The origins of cosmic rays and quantum effects on gravity
NASA Technical Reports Server (NTRS)
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.
Status and Recent Results from the Cream Experiment
NASA Astrophysics Data System (ADS)
Seo, E. S.; Ahn, H. S.; Bhoyar, P.; Eaton, J.; Ganel, O.; Han, J. H.; Haque, A.; Kim, K. C.; Kim, M. H.; Lee, M. H.; Lee, S. E.; Lutz, L.; Malinin, A.; Ofoha, O.; Ryu, S. S.; Smith, B. P.; Vartanyan, A.; Walpole, P.; Wu, J.; Yoo, J. H.; Yoon, Y. S.; Anderson, T.; Conklin, N. B.; Coutu, S.; Geske, M.; Mognet, S. I.; Barbier, L.; Link, J. T.; Mitchell, J. W.; Barrau, A.; Buénerd, M.; Coste, B.; Derome, L.; Mangin-Brinet, M.; Putze, A.; Sallaz-Damaz, Y.; Bazer-Bachi, R.; Beatty, J. J.; Brandt, T. J.; Bigongiari, G.; Maestro, P.; Zei, R.; Jeon, J. A.; Na, G.; Nam, J.; Nam, S.; Park, I. H.; Park, N. H.; Yang, J.; Menchaca-Rocha, A.; Nutter, S.
2011-06-01
The Cosmic Ray Energetics And Mass (CREAM) balloon-borne experiment has accumulated ~156 days of exposure during five successful flights over Antarctica. Energy measurements are made with a transition radiation detector and an ionization calorimeter. Charge measurements are made with timing scintillators, pixelated Si, and Cherenkov detectors to minimize the effect of backscattered particles. High energy cosmic-ray data were collected over a wide energy range from ~ 1010 to ~ 1015 eV at an average altitude of ~38.5 km, with ~3.9 g/cm2 atmospheric overburden. All cosmic-ray elements from protons (Z = 1) to iron nuclei (Z = 26) are separated with excellent charge resolution. The instrument performance, results from the ongoing data analysis, and their implications on cosmic-ray origin, acceleration and propagation are discussed.
A Cosmic Dust Sensor Based on an Array of Grid Electrodes
NASA Astrophysics Data System (ADS)
Li, Y. W.; Bugiel, S.; Strack, H.; Srama, R.
2014-04-01
We described a low mass and high sensitivity cosmic dust trajectory sensor using a array of grid segments[1]. the sensor determines the particle velocity vector and the particle mass. An impact target is used for the detection of the impact plasma of high speed particles like interplanetary dust grains or high speed ejecta. Slower particles are measured by three planes of grid electrodes using charge induction. In contrast to conventional Dust Trajectory Sensor based on wire electrodes, grid electrodes a robust and sensitive design with a trajectory resolution of a few degree. Coulomb simulation and laboratory tests were performed in order to verify the instrument design. The signal shapes are used to derive the particle plane intersection points and to derive the exact particle trajectory. The accuracy of the instrument for the incident angle depends on the particle charge, the position of the intersection point and the signal-to-noise of the charge sensitive amplifier (CSA). There are some advantages of this grid-electrodes based design with respect to conventional trajectory sensor using individual wire electrodes: the grid segment electrodes show higher amplitudes (close to 100%induced charge) and the overall number of measurement channels can be reduced. This allows a compact instrument with low power and mass requirements.
Some Behavioral Effects of Exposure to Low Doses of Fe-56 Particles
NASA Technical Reports Server (NTRS)
Rabin, Bernard M.; Joseph, James A.; Shukitt-Hale, Barbara
1999-01-01
Future missions in space (such as a mission to Mars) will involve long-term travel beyond the magnetic field of the Earth. As a result, astronauts will be exposed to radiation qualities and doses that differ from those experienced in low earth orbit, including exposure to heavy particles, such as Fe-56, which are a component of cosmic rays. Although the hazards of exposure to heavy particles are often minimized, they can affect neural functioning, and as a consequence, behavior. Unless the effects of exposure to cosmic rays can somehow be reduced, their effects on the brain throughout long duration flights could be disastrous. In the extreme case, it is possible that the effects of cosmic rays on space travelers could result in symptomatology resembling that of Alzheimer's or Parkinson's diseases or of advancing age, including significant cognitive and/or motor impairments. Because successful operations in space depend in part on the performance capabilities of astronauts, such impairments could jeopardize their ability to satisfy mission requirements, as well as have long-term consequences on the health of astronauts. As such, understanding the nature and extent of this risk may be vital to the effective performance and possibly the survival of astronauts during future missions in space.
NASA Astrophysics Data System (ADS)
Tomaschitz, Roman
2013-10-01
A statistical description of the all-particle cosmic-ray spectrum is given in the 10^{14}\\ \\text{eV} to 10^{20}\\ \\text{eV} interval. The high-energy cosmic-ray flux is modeled as an ultra-relativistic multi-component plasma, whose components constitute a mixture of nearly ideal but nonthermal gases of low density and high temperature. Each plasma component is described by an ultra-relativistic power-law density manifested as spectral peak in the wideband fit. The “knee” and “ankle” features of the high- and ultra-high-energy spectrum turn out to be the global and local extrema of the double-logarithmic E3-scaled flux representation in which the spectral fit is performed. The all-particle spectrum is covered by recent data sets from several air shower arrays, and can be modeled as three-component plasma in the indicated energy range extending over six decades. The temperature, specific number density, internal energy and entropy of each plasma component are extracted from the partial fluxes in the broadband fit. The grand partition function and the extensive entropy functional of a non-equilibrated gas mixture with power-law components are derived in phase space by ensemble averaging.
Cosmic Ray Flux in the Presence of a Neutral Background
NASA Technical Reports Server (NTRS)
Wilson, Thomas L.; Lodhi, Arfin; Diaz, Abel
2007-01-01
The study of cosmic rays (CRs) is a very mature subject developed around the concept of radiative particle flux phi as a mono-variant function of energy E, that is phi = phi(E). This is based on the notion of the cosmos as being filled with cosmic radiation in the form of a collisionless exosphere of plasma. Neutrals, however, are likewise ubiquitous in space and planetary trapped-radiation belts. It will be shown that in the presence of a neutral background of density rho, flux phi is actually bivariant in energy E and rho, creating a surface phi(E,rho). This is an intrinsic property of charged-particle flux, that flux is not merely a function of E but is dependent upon density rho when a background of neutrals is present. The effect is produced by multiple scattering of charged particles off neutral and ionized atoms along with ionization loss where charged and neutral populations interact. For the harder portion of CR spectra, flux is mono-variant but at nonrelativistic energies (below approx, 350 MeV) it becomes sensitive to the presence of neutral backgrounds. The dependence of phi(E,rho) upon background neutrals is helpful in discussing the anomalous CR (ACR) flux made up of ionized components of the heliospheric neutral atmosphere.
NASA Astrophysics Data System (ADS)
Meier, Matthias M.; Hubiak, Melina
2010-05-01
In radiation protection, the Q-factor has been defined to describe the biological effectiveness of the energy deposition or absorbed dose to humans in the mixed radiation fields at aviation altitudes. This particular radiation field is generated by the interactions of primary cosmic particles with the atoms of the constituents of the Earth’s atmosphere. Thus the intensity, characterized by the ambient dose equivalent rate H∗(10), depends on the flight altitude and the energy spectra of the particles, mainly protons and alpha particles, impinging on the atmosphere. These charged cosmic projectiles are deflected both by the interplanetary and the Earth’s magnetic field such that the corresponding energy spectra are modulated by these fields. The solar minimum is a time period of particular interest since the interplanetary magnetic field is weakest within the 11-year solar cycle and the dose rates at aviation altitudes reach their maximum due to the reduced shielding of galactic cosmic radiation. For this reason, the German Aerospace Center (DLR) performed repeated dosimetric on-board measurements in cooperation with several German airlines during the past solar minimum from March 2006 to August 2008. The Q-factors measured with a TEPC range from 1.98 at the equator to 2.60 in the polar region.
Performance test of the Multi-gap Resistive Plate Chamber (MRPC) with cosmic ray
NASA Astrophysics Data System (ADS)
Ikeda, Michihiko; Akieda, Tomomi; Tomita, Shoko; Ninomiya, Aki
2014-09-01
MRPC is a gaseous ionization detector, which a good timing resolution has been used practically in the nuclear and particle physics experiment. A mixed gas of SF6 and Fleon 134a was flowed through the gaps between high resistive plates (500 μm thickness glass). A high electric field of ~2 ×106 [V/m] was applied between the plates. A charged particle passes through the MRPC and causes avalanche amplification. We constructed a relatively small MRPC with a readout pad (20 mm × 50 mm). The development is motivated by feasibility study of the MRPC as a photon tagger at the Research Center for Electron Photon Science (ELPH), Tohoku University. The photon tagger needs a good timing resolution (<100 ps), therefore we studied the small size MRPC, while a large sized MRPCs are widely used in nuclear and particle experiments. The MRPC can operate under the strong magnetic field and thus it can be a good candidate as an electron detector placed in the magnet. We tested the HV dependence of time resolution of the MRPC with cosmic rays. The MRPC will be demonstrated at the open campus of the Tohoku University as an example of nuclear experimental detectors. We will measure the zenith angle and velocity distributions of cosmic ray.
Evolution of NASA Scientific Ballooning and Particle Astrophysics Research
NASA Astrophysics Data System (ADS)
Jones, William Vernon
2017-01-01
Particle astrophysics research has a history in ballooning that spans over 100 years, ever since Victor Hess discovered cosmic rays on a manned balloon in 1912. The NASA Particle Astrophysics Program currently covers the origin, acceleration and transport of Galactic cosmic rays, plus the Nature of Dark Matter and Ultrahigh Energy Neutrinos. Progress in each of these topics has come from sophisticated instrumentation flown on Long Duration Balloon (LDB) flights around Antarctica for more than two decades. Super Pressure Balloons (SPB) and International Space Station (ISS) platforms are emerging opportunities that promise major steps forward for these and other objectives. NASA has continued development and qualification flights leading to SPB flights capable of supporting 1000 kg science instruments to 33 km for upwards of hundred day missions, with plans for increasing the altitude to 38 km. This goal is even more important now, in view of the Astro2010 Decadal Study recommendation that NASA should support Ultra-Long Duration Balloon (ULDB) flight development for studies of particle astrophysics, cosmology and indirect detection of dark matter. The mid-latitude test flight of an 18.8 MCF SPB launched from Wanaka, NZ in 2015 achieved 32 days of nearly constant altitude exposure, and an identical SPB launched from Wanaka in 2016 with a science payload flew for 46 days. Scientific ballooning as a vital infrastructure component for cosmic ray and general astrophysics investigations, including training for young scientists, graduate and undergraduate students, leading up to the 2020 Decadal Study and beyond, will be presented and discussed.
Embryogenesis and organogenesis of Carausius morosus under spaceflight conditions.
Bucker, H; Facius, R; Horneck, G; Reitz, G; Graul, E H; Berger, H; Hoffken, H; Ruther, W; Heinrich, W; Beaujean, R; Enge, W
1986-01-01
The influence of cosmic radiation and/or microgravity on insect development was studied during the 7 day German Spacelab Mission D1. Eggs of Carausius morosus of five stages differing in sensitivity to radiation and in capacity to regeneration were allowed to continue their development in the BIORACK 22 degrees C incubator, either at microgravity conditions or on the 1 g reference centrifuge. Using the Biostack concept--eggs in monolayers were sandwiched between visual track detectors--and the 1 g reference centrifuge, we were able to separate radiation effects from microgravity effects and also from combined effects of these two factors in space. After retrieval, hatching rates, growth kinetics and anomaly frequencies were determined in the different test samples. The early stages of development turned out to be highly sensitive to single hits of cosmic ray particles as well as to the temporary exposure to microgravity during their development. In some cases, the combined action of radiation and microgravity even amplified the effects exerted by the single parameters of space. Hits by single HZE particles caused early effects, such as body anomalies, as well as late effects, such as retarded growth after hatching. Microgravity exposure lead to a reduced hatching rate. A synergistic action of HZE particle hits and microgravity was established in the unexpectedly high frequency of anomal larvae. However, it cannot be excluded, that cosmic background radiation or low LET HZE particles are also causally involved in damage observed in the microgravity samples.
NASA Astrophysics Data System (ADS)
Slatyer, Tracy R.
2016-01-01
Any injection of electromagnetically interacting particles during the cosmic dark ages will lead to increased ionization, heating, production of Lyman-α photons and distortions to the energy spectrum of the cosmic microwave background, with potentially observable consequences. In this paper we describe numerical results for the low-energy electrons and photons produced by the cooling of particles injected at energies from keV to multi-TeV scales, at arbitrary injection redshifts (but focusing on the post-recombination epoch). We use these data, combined with existing calculations modeling the cooling of these low-energy particles, to estimate the resulting contributions to ionization, excitation and heating of the gas, and production of low-energy photons below the threshold for excitation and ionization. We compute corrected deposition-efficiency curves for annihilating dark matter, and demonstrate how to compute equivalent curves for arbitrary energy-injection histories. These calculations provide the necessary inputs for the limits on dark matter annihilation presented in the accompanying paper I, but also have potential applications in the context of dark matter decay or deexcitation, decay of other metastable species, or similar energy injections from new physics. We make our full results publicly available at http://nebel.rc.fas.harvard.edu/epsilon, to facilitate further independent studies. In particular, we provide the full low-energy electron and photon spectra, to allow matching onto more detailed codes that describe the cooling of such particles at low energies.
Monte Carlo simulations of particle acceleration at oblique shocks
NASA Technical Reports Server (NTRS)
Baring, Matthew G.; Ellison, Donald C.; Jones, Frank C.
1994-01-01
The Fermi shock acceleration mechanism may be responsible for the production of high-energy cosmic rays in a wide variety of environments. Modeling of this phenomenon has largely focused on plane-parallel shocks, and one of the most promising techniques for its study is the Monte Carlo simulation of particle transport in shocked fluid flows. One of the principal problems in shock acceleration theory is the mechanism and efficiency of injection of particles from the thermal gas into the accelerated population. The Monte Carlo technique is ideally suited to addressing the injection problem directly, and previous applications of it to the quasi-parallel Earth bow shock led to very successful modeling of proton and heavy ion spectra, as well as other observed quantities. Recently this technique has been extended to oblique shock geometries, in which the upstream magnetic field makes a significant angle Theta(sub B1) to the shock normal. Spectral resutls from test particle Monte Carlo simulations of cosmic-ray acceleration at oblique, nonrelativistic shocks are presented. The results show that low Mach number shocks have injection efficiencies that are relatively insensitive to (though not independent of) the shock obliquity, but that there is a dramatic drop in efficiency for shocks of Mach number 30 or more as the obliquity increases above 15 deg. Cosmic-ray distributions just upstream of the shock reveal prominent bumps at energies below the thermal peak; these disappear far upstream but might be observable features close to astrophysical shocks.
Laboratory Studies of the Optical Properties and Condensation Processes of Cosmic Dust Grains
NASA Technical Reports Server (NTRS)
Abbas, M. M.; Craven, P. D.; Spann, J. F.; Tankosic, D.; LeClair, A.; West, E.; Sheldon, R.; Witherow, W. K.; Gallagher, D. L.; Adrian, M. L.
2002-01-01
A laboratory facility for conducting a variety of experiments on single isolated dust particles of astrophysical interest levitated in an electrodynamics balance has been developed at NASA/Marshall Space Flight Center. The objective of the research is to employ this experimental technique for studies of the physical and optical properties of individual cosmic dust grains of 0.1-100 micron size in controlled pressure/temperatures environments simulating astrophysical conditions. The physical and optical properties of the analogs of interstellar and interplanetary dust grains of known composition and size distribution will be investigated by this facility. In particular, we will carry out three classes of experiments to study the micro-physics of cosmic dust grains. (1) Charge characteristics of micron size single dust grains to determine the photoelectric efficiencies, yields, and equilibrium potentials when exposed to UV radiation. (2) Infrared optical properties of dust particles (extinction coefficients and scattering phase functions) in the 1-30 micron region using infrared diode lasers and measuring the scattered radiation. (3) Condensation experiments to investigate the condensation of volatile gases on colder nucleated particles in dense interstellar clouds and lower planetary atmospheres. The condensation experiments will involve levitated nucleus dust grains of known composition and initial mass (or m/q ratio), cooled to a temperature and pressure (or scaled pressure) simulating the astrophysical conditions, and injection of a volatile gas at a higher temperature from a controlled port. The increase in the mass due to condensation on the particle will be monitored as a function of the dust particle temperature and the partial pressure of the injected volatile gas. The measured data will permit determination of the sticking coefficients of volatile gases and growth rates of dust particles of astrophysical interest. Some preliminary results based on measurements of photoelectric emission and radiation pressure on single isolated 0.2 to 6.6 micron size silica particles exposed to UV radiation at 120-200 nm and green laser light at 532 nm are presented.
Ionisation and discharge in cloud-forming atmospheres of brown dwarfs and extrasolar planets
NASA Astrophysics Data System (ADS)
Helling, Ch; Rimmer, P. B.; Rodriguez-Barrera, I. M.; Wood, Kenneth; Robertson, G. B.; Stark, C. R.
2016-07-01
Brown dwarfs and giant gas extrasolar planets have cold atmospheres with rich chemical compositions from which mineral cloud particles form. Their properties, like particle sizes and material composition, vary with height, and the mineral cloud particles are charged due to triboelectric processes in such dynamic atmospheres. The dynamics of the atmospheric gas is driven by the irradiating host star and/or by the rotation of the objects that changes during its lifetime. Thermal gas ionisation in these ultra-cool but dense atmospheres allows electrostatic interactions and magnetic coupling of a substantial atmosphere volume. Combined with a strong magnetic field \\gg {{B}\\text{Earth}} , a chromosphere and aurorae might form as suggested by radio and x-ray observations of brown dwarfs. Non-equilibrium processes like cosmic ray ionisation and discharge processes in clouds will increase the local pool of free electrons in the gas. Cosmic rays and lighting discharges also alter the composition of the local atmospheric gas such that tracer molecules might be identified. Cosmic rays affect the atmosphere through air showers in a certain volume which was modelled with a 3D Monte Carlo radiative transfer code to be able to visualise their spacial extent. Given a certain degree of thermal ionisation of the atmospheric gas, we suggest that electron attachment to charge mineral cloud particles is too inefficient to cause an electrostatic disruption of the cloud particles. Cloud particles will therefore not be destroyed by Coulomb explosion for the local temperature in the collisional dominated brown dwarf and giant gas planet atmospheres. However, the cloud particles are destroyed electrostatically in regions with strong gas ionisation. The potential size of such cloud holes would, however, be too small and might occur too far inside the cloud to mimic the effect of, e.g. magnetic field induced star spots.
Rühm, Werner; Mares, V; Pioch, C; Weitzenegger, E; Vockenroth, R; Paretzke, H G
2009-04-01
Air crew members and airline passengers are continuously exposed to cosmic radiation during their flights. Particles ejected by the sun during so-called solar particle events (SPEs) in periods of high solar activity can contribute to this exposure. In rare cases the dose from a single SPE might even exceed the annual dose limit of 1 mSv above which dose monitoring of air crews is legally required in Germany. Measurements performed by means of neutron monitors have already shown that the relative intensity of secondary neutrons from cosmic radiation is enhanced during an SPE, particularly at regions close to the magnetic poles of the Earth where shielding of the cosmic radiation by the geomagnetic field is low. Here we describe a Bonner sphere spectrometer installed at the Koldewey station at 79 degrees N, i.e. about 1,000 km from the geographic North pole, which is designed to provide first experimental data on the time-dependent energy spectrum of neutrons produced in the atmosphere during an SPE. This will be important to calculate doses from these neutrons to air crew members. The system is described in detail and first results are shown that were obtained during quiet periods of sun activity.
Particle Acceleration in Relativistic Outflows
NASA Technical Reports Server (NTRS)
Bykov, Andrei; Gehrels, Neil; Krawczynski, Henric; Lemoine, Martin; Pelletier, Guy; Pohl, Martin
2012-01-01
In this review we confront the current theoretical understanding of particle acceleration at relativistic outflows with recent observational results on various source classes thought to involve such outflows, e.g. gamma-ray bursts, active galactic nuclei, and pulsar wind nebulae. We highlight the possible contributions of these sources to ultra-high-energy cosmic rays.
Fermilab | Science at Fermilab | Experiments & Projects | Cosmic Frontier
Proposed Projects and Experiments Fermilab's Tevatron Questions for the Universe Theory Computing High Answers Submit a Question Frontiers of Particle Physics Benefits to Society Benefits to Society Medicine Inquiring Minds Questions About Physics Other High-Energy Physics Sites More About Particle Physics Library
Cosmic Ray Propagation through the Magnetic Fields of the Galaxy with Extended Halo
NASA Technical Reports Server (NTRS)
Zhang, Ming
2005-01-01
In this project we perform theoretical studies of 3-dimensional cosmic ray propagation in magnetic field configurations of the Galaxy with an extended halo. We employ our newly developed Markov stochastic process methods to solve the diffusive cosmic ray transport equation. We seek to understand observations of cosmic ray spectra, composition under the constraints of the observations of diffuse gamma ray and radio emission from the Galaxy. The model parameters are directly are related to properties of our Galaxy, such as the size of the Galactic halo, particle transport in Galactic magnetic fields, distribution of interstellar gas, primary cosmic ray source distribution and their confinement in the Galaxy. The core of this investigation is the development of software for cosmic ray propagation models with the Markov stochastic process approach. Values of important model parameters for the halo diffusion model are examined in comparison with observations of cosmic ray spectra, composition and the diffuse gamma-ray background. This report summarizes our achievement in the grant period at the Florida Institute of Technology. Work at the co-investigator's institution, the University of New Hampshire, under a companion grant, will be covered in detail by a separate report.
NASA Technical Reports Server (NTRS)
Pinsky, L. S.
1972-01-01
The detection and measurement of the cosmic ray charge spectrum for nuclei heavier than iron (Fe, Z = 26) are discussed. These trans-iron nuclei are of great interest for several reasons. They promise to be one of the more sensitive clocks for use in determining the age of cosmic rays. The discovery of radioactive nuclides and their decay products in the primary flux, will allow an estimation of the elapsed time since these cosmic rays were synthesized. In addition, the relatively short interaction length of the very heavy trans-iron particles makes their relative abundance a source of information regarding the amount of interstellar matter that they had to traverse to reach the earth. A study of the trans-iron cosmic rays may provide clues as to the very processes of nucleosyntheses by which the bulk of the trans-iron nuclei in the universe are produced. This in turn may shed light on the mechanics of the supernova, which is postulated to be the major source of all cosmic rays. Finally, trans-iron cosmic ray experiments may demonstrate the existence of the recently postulated super-heavy nuclei.
Extrapolating cosmic ray variations and impacts on life: Morlet wavelet analysis
NASA Astrophysics Data System (ADS)
Zarrouk, N.; Bennaceur, R.
2009-07-01
Exposure to cosmic rays may have both a direct and indirect effect on Earth's organisms. The radiation may lead to higher rates of genetic mutations in organisms, or interfere with their ability to repair DNA damage, potentially leading to diseases such as cancer. Increased cloud cover, which may cool the planet by blocking out more of the Sun's rays, is also associated with cosmic rays. They also interact with molecules in the atmosphere to create nitrogen oxide, a gas that eats away at our planet's ozone layer, which protects us from the Sun's harmful ultraviolet rays. On the ground, humans are protected from cosmic particles by the planet's atmosphere. In this paper we give estimated results of wavelet analysis from solar modulation and cosmic ray data incorporated in time-dependent cosmic ray variation. Since solar activity can be described as a non-linear chaotic dynamic system, methods such as neural networks and wavelet methods should be very suitable analytical tools. Thus we have computed our results using Morlet wavelets. Many have used wavelet techniques for studying solar activity. Here we have analysed and reconstructed cosmic ray variation, and we have better depicted periods or harmonics other than the 11-year solar modulation cycles.
Cosmological solutions in spatially curved universes with adiabatic particle production
NASA Astrophysics Data System (ADS)
Aresté Saló, Llibert; de Haro, Jaume
2017-03-01
We perform a qualitative and thermodynamic study of two models when one takes into account adiabatic particle production. In the first one, there is a constant particle production rate, which leads to solutions depicting the current cosmic acceleration but without inflation. The other one has solutions that unify the early and late time acceleration. These solutions converge asymptotically to the thermal equilibrium.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bakke, K., E-mail: kbakke@fisica.ufpb.br; Furtado, C., E-mail: furtado@fisica.ufpb.br; Belich, H., E-mail: belichjr@gmail.com
2016-09-15
From the modified Maxwell theory coupled to gravity, we establish a possible scenario of the violation of the Lorentz symmetry and write an effective metric for the cosmic string spacetime. Then, we investigate the arising of an analogue of the Anandan quantum phase for a relativistic Dirac neutral particle with a permanent magnetic dipole moment in the cosmic string spacetime under Lorentz symmetry breaking effects. Besides, we analyse the influence of the effects of the Lorentz symmetry violation and the topology of the defect on the Aharonov–Casher geometric quantum phase in the nonrelativistic limit.
High Energy Astronomy Observatory (HEAO)
1979-01-01
This photograph was taken during encapsulation of the High Energy Astronomy Observatory (HEAO)-3. Designed and developed by TRW, Inc. under the direction of the Marshall Space Flight Center, the objectives of the HEAO-3 were to survey and map the celestial sphere for gamma-ray flux and make detailed measurements of cosmic-ray particles. It carried three scientific experiments: a gamma-ray spectrometer, a cosmic-ray isotope experiment, and a heavy cosmic-ray nuclei experiment. The HEAO-3 was originally identified as HEAO-C but the designation was changed once the spacecraft achieved orbit. The Marshall Space Flight Center had the project management responsibilities for the HEAO missions.
High Energy Astronomy Observatory (HEAO)
1979-01-01
This photograph shows the High Energy Astronomy Observatory (HEAO)-3 being prepared for encapsulation. Designed and developed by TRW, Inc. under the direction of the Marshall Space Flight Center, the objectives of the HEAO-3 were to survey and map the celestial sphere for gamma-ray flux and make detailed measurements of cosmic-ray particles. It carried three scientific experiments: a gamma-ray spectrometer, a cosmic-ray isotope experiment, and a heavy cosmic-ray nuclei experiment. The HEAO-3 was originally identified as HEAO-C but the designation was changed once the spacecraft achieved orbit. The Marshall Space Flight Center had the project management responsibilities for the HEAO missions.
High Energy Astronomy Observatory (HEAO)
1979-01-01
This photograph shows the High Energy Astronomy Observatory (HEAO)-3 being assembled at TRW, Inc. Designed and developed by TRW, Inc. under the direction of the Marshall Space Flight Center, the objectives of the HEAO-3 were to survey and map the celestial sphere for gamma-ray flux and make detailed measurements of cosmic-ray particles. It carried three scientific experiments: a gamma-ray spectrometer, a cosmic-ray isotope experiment, and a heavy cosmic-ray nuclei experiment. The HEAO-3 was originally identified as HEAO-C but the designation was changed once the spacecraft achieved orbit. The Marshall Space Flight Center had the project management responsibilities for the HEAO missions.
Physics through the 1990s: Gravitation, cosmology and cosmic-ray physics
NASA Technical Reports Server (NTRS)
1986-01-01
The volume contains recommendations for space-and ground-based programs in gravitational physics, cosmology, and cosmic-ray physics. The section on gravitation examines current and planned experimental tests of general relativity; the theory behind, and search for, gravitational waves, including sensitive laser-interferometric tests and other observations; and advances in gravitation theory (for example, incorporating quantum effects). The section on cosmology deals with the big-bang model, the standard model from elementary-particle theory, the inflationary model of the Universe. Computational needs are presented for both gravitation and cosmology. Finally, cosmic-ray physics theory (nucleosynthesis, acceleration models, high-energy physics) and experiment (ground and spaceborne detectors) are discussed.
Giant molecular clouds as regions of particle acceleration
NASA Technical Reports Server (NTRS)
Dogiel, V. A.; Gurevich, A. V.; Istomin, Y. N.; Zybin, K. A.
1985-01-01
One of the most interesting results of investigations carried out on the satellites SAS-II and COS-B is the discovery of unidentified discrete gamma sources. Possibly a considerable part of them may well be giant molecular clouds. Gamma emission from clouds is caused by the processes with participation of cosmic rays. The estimation of the cosmic ray density in clouds has shown that for the energy E approx. = I GeV their density can 10 to 1000 times exceed the one in intercloud space. We have made an attempt to determine the mechanism which could lead to the increase in the cosmic ray density in clouds.
NASA Astrophysics Data System (ADS)
Bartos, Imre; Kowalski, Marek
2017-04-01
With the recent discovery of gravitational waves and high-energy cosmic neutrinos, we are witnessing the beginning of a new era in multimessenger astronomy. The exploration of the Universe through these new messengers, along with electromagnetic radiation and cosmic rays, gives us new insights into the most extreme energetic cosmic events, environments and particle accelerators. The objects of interest range from galaxies with accreting supermassive black holes in their centre to collapsing stars and coalescing stellar black holes. In this ebook we provide an introduction to the scientific questions surrounding these new messengers and the detectors and observational techniques used to study them, together with an overview of current and future directions in the field.
An experiment to measure the energy spectrum of cosmic ray antiprotons from 100 to 1000 MeV
NASA Technical Reports Server (NTRS)
Salamon, M. H.; Price, P. B.; Barwick, S. W.; Lowder, D. M.; Ahlen, S. P.
1985-01-01
Production models were developed and the confirmation of each one had significant astrophysical impact. These include radical modifications of propagation models, cosmic ray antiprotons injection from neighboring domains of antimatter, p production by evaporating primordial black holes, and cosmic ray p's as annihilation products of supersymmetry particles that might make up the dark dynamical mass of the Galaxy. It is that p's originating from supersymmetric parents might have distinct spectral features that would survive solar modulation; in one model, higgsino annihilation proceeds through the bb quark-antiquark channel, producing a spectral bump at approx. 0.3 GeV in the p spectrum.
COMPARISON OF COSMIC-RAY ENVIRONMENTS ON EARTH, MOON, MARS AND IN SPACECARFT USING PHITS.
Sato, Tatsuhiko; Nagamatsu, Aiko; Ueno, Haruka; Kataoka, Ryuho; Miyake, Shoko; Takeda, Kazuo; Niita, Koji
2017-09-29
Estimation of cosmic-ray doses is of great importance not only in aircrew and astronaut dosimetry but also in evaluation of background radiation exposure to public. We therefore calculated the cosmic-ray doses on Earth, Moon and Mars as well as inside spacecraft, using Particle and Heavy Ion Transport code System PHITS. The same cosmic-ray models and dose conversion coefficients were employed in the calculation to properly compare between the simulation results for different environments. It is quantitatively confirmed that the thickness of physical shielding including the atmosphere and soil of the planets is the most important parameter to determine the cosmic-ray doses and their dominant contributors. The comparison also suggests that higher solar activity significantly reduces the astronaut doses particularly for the interplanetary missions. The information obtained from this study is useful in the designs of the future space missions as well as accelerator-based experiments dedicated to cosmic-ray research. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Model structure of a cosmic-ray mediated stellar or solar wind
NASA Technical Reports Server (NTRS)
Lee, M. A.; Axford, W. I.
1988-01-01
An idealized hydrodynamic model is presented for the mediation of a free-streaming stellar wind by galactic cosmic rays or energetic particles accelerated at the stellar wind termination shock. The spherically-symmetric stellar wind is taken to be cold; the only body force is the cosmic ray pressure gradient. The cosmic rays are treated as a massless fluid with an effective mean diffusion coefficient k proportional to radial distance r. The structure of the governing equations is investigated both analytically and numerically. Solutions for a range of values of k are presented which describe the deceleration of the stellar wind and a transition to nearly incompressible flow and constant cosmic ray pressure at large r. In the limit of small k the transition steepens to a strong stellar wind termination shock. For large k the stellar wind is decelerated gradually with no shock transition. It is argued that the solutions provide a simple model for the mediation of the solar wind by interstellar ions as both pickup ions and the cosmic ray anomalous component which together dominate the pressure of the solar wind at large r.
Final Report for DoE Grant DE-SC-0011689 - Studies of Particle Astrophysics at the Cosmic Frontier
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nitz, David F.; Fick, Brian E.
Our research focuses on the “Cosmic Frontier”, one of the three principle thrusts of the DoE Office of Science High Energy Physics research program. The 2013 community summer study “Snowmass on the Mississippi” catalyzed joint work to describe the status and future prospects of this research thrust. Over its history, the field of cosmic ray studies has provided many discoveries of central importance to the the progress of high energy physics, including the identification of new elementary particles, measurements of particle interactions far above accelerator energies, and the confirmation of neutrino oscillations. In our research we continued this tradition, employingmore » 2 instruments (the Auger Observatory and the HAWC Observatory) to study high energy physics questions using cosmic rays. One approach to addressing particle physics questions at the cosmic frontier is to study the very highest energy cosmic rays. This has been the major thrust of our research effort. The two largest currently operating ultra-high energy cosmic ray (UHECR) observatories are the Pierre Auger Observatory in the Southern hemisphere, covering an area of 3000 km 2 and the Telescope Array (TA) in the Northern hemisphere, covering about 700 km 2. The observatories sample the cosmic ray air showers at ground level (with 1660 water Cerenkov stations in the Auger surface detector), and also measure the longitudinal development of air showers on clear moonless nights (approx. 10% of the events) using atmospheric fluorescence detectors. The observatories have recently installed low energy extensions, which provide an overlap with the LHC energy regime. The Auger and TA teams have established joint working groups to discuss experimental methods, compare data analyses and modeling, and perform cross calibrations. Another approach is to study high energy gamma rays. The High Altitude Water Cerenkov (HAWC) gamma-ray observatory is located at 4100 m above sea level near Pico de Orizaba in central Mexico. HAWC is the most sensitive, wide field of view, TeV gamma-ray observatory in operation. After 4 years of construction, operation of the full detector began in March 2015. The HAWC detector contains 300 tanks each 7.3 m in diameter and 4.5 m deep containing pure water. Each water tank is instrumented with 4 upward-viewing photomultiplier tubes mounted at their bottom. The water tanks record the energy deposited by and arrival times of the constituent components of impinging extensive air showers (EAS). The tanks are close-packed to optimize the spatial sampling of the shower front. The distribution of deposited energy across the shower is used for gamma-hadron rejection. Showers with large energy deposit away from the core are rejected as being hadron-initiated. The detector operates at full efficiency above 3 TeV. The angular resolution above that energy approaches 0.1 degree. As the detector operates both day and night, the wide field of view of ~2 sr, allows ~2/3 of the sky to be observed each day.« less
Cosmic Dust in ~50 KG Blocks of Blue Ice from Cap-Prudhomme and Queen Alexandra Range, Antarctica
NASA Astrophysics Data System (ADS)
Maurette, M.; Cragin, J.; Taylor, S.
1992-07-01
Favorable Antarctic blue ice fields have produced a large number of meteorite finds because of the ice ablation concentration process (Cassidy et al., 1982). Such ice fields should also concentrate cosmic dust grains including both spherules and unmelted micrometeorites. Here we present preliminary results of concentrations of cosmic dust grains in ice from two very different Antarctic blue ice fields. The first sample (~60 kg) was collected in January 1987 from the surface of the blue ice field at Cap-Prudhomme (CP), near the French station of Dumont d'Urville, by a team from the "Laboratoire de Glaciologie du CNRS" (A. Barnola). The second sample (~50 kg), was retrieved from a meteorite stranding surface near the Queen Alexandra range (QUE) by a team (M. Burger, W. Cassidy, and R.Walker) of the ANSMET 1990 field expedition in Antarctica. Both samples were transported frozen to the laboratory where they were subdivided and processed. The CP sample was cut with a stainless steel saw into 4 pieces while the QUE sample, which had the top surface identified, was cut into three equal (~15 cm) horizontal layers to provide constituent variability with depth. All subsequent work on both samples was performed in a class 100 clean room using procedures developed by M. de Angelis and M. Maurette aimed at minimizing the loss of extraterrestrial particles. Pieces of both samples were cleaned by rinsing thoroughly with ultrapure water (Milli-O) and then melted in polyethylene containers in a microwave oven. Aliquots were decanted for chemical analysis and the remaining meltwater was filtered through stainless steel sieves for collection of large (>30 micrometers) particles. Using a 30X binocular microscope particles were hand picked for subsequent SEM/EDX analyses. Our initial objective was to compare the cosmic dust concentration in ice from the two locations. But this comparison was only partial because in the CP-ice, only magnetic spherules of >50 micrometers were studied whereas the QUE-ice studies included measurements of the depth variation of various characteristics, such as the size distribution and concentration of both cosmic spherules and unmelted chondritic micrometeorites (AMMs), the concentrations of grains in the ~1-10-micrometer size range, and the concentration of trace elements in the ice. In addition both magnetic and nonmagnetic particles were collected from the QUE-ice. The concentration of chondritic spherules 50 micrometers in size is similar at both locations: in the CP-ice 5 spherules were found in 40 kg of residual ice (after cleaning), and 7 spherules (including a nonmagnetic one) were recovered from 50kg of QUE-ice. The QUE sample contained 11 AMMs (including 3 grains with sizes ~30-50 micrometers) resulting in a ratio of unmelted to melted micrometeorites with sizes >50 micrometers (~1), which is much lower than the CP ratio of >5 (obtained for particles subsequently recovered from 360 tons of CP-ice). The QUE sample showed that particles >100 micrometers in size are found primarily within the top 15 m of ice while smaller particles are found in the bottom layers (30-50 cm). In contrast to CP-ice, QUE-ice contains many annealed stress cracks, that etch very quickly in water. Despite the very different glaciological and climatological regimes at the CP and QUE ice fields, concentrations of cosmic spherules are surprisingly similar. The ratio of AMMs to spherules does vary, however. The depth variations of the characteristics of cosmic dust grains trapped in the ~50-cm-thick top layer of a blue ice field are already very useful to select favorable zones to collect micrometeorites. In addition, they might provide insight into both climatic and ice flow parameters. Acknowledgements. We thank W.A. Cassidy and G. Crozaz for comments and R.M. Walker for his support and interest. REFERENCES. Cassidy W.A. and Rancitelli L.A. (1982) Am. Scientist 70, 156-164.
Calculations of low-frequency radio emission by cosmic-ray-induced particle showers
NASA Astrophysics Data System (ADS)
García-Fernández, Daniel; Revenu, Benoît; Charrier, Didier; Dallier, Richard; Escudie, Antony; Martin, Lilian
2018-05-01
The radio technique for the detection of high-energy cosmic rays consists in measuring the electric field created by the particle showers created inside a medium by the primary cosmic ray. The electric field is then used to infer the properties of the primary particle. Nowadays, the radio technique is a standard, well-established technique. While most current experiments measure the field at frequencies above 20 MHz, several experiments have reported a large emission at low frequencies, below 10 MHz. The EXTASIS experiment aims at measuring again and understanding this low-frequency electric field. Since at low frequencies the standard far-field approximation for the calculation of the electric field does not necessarily hold, in order to comprehend the low-frequency emission we need to go beyond the far-field approximation. We present in this work a formula for the electric field created by a particle track inside a dielectric medium that is valid for all frequencies. We then implement this formula in the SELFAS Monte Carlo code and calculate the low-frequency electric field of the extensive air shower (EAS). We also study the electric field of a special case of the transition radiation mechanism when the EAS particles cross the air-soil boundary. We introduce the sudden death pulse, the direct emission caused by the coherent deceleration of the shower front at the boundary, as a first approximation to the whole electric field for the air-soil transition, and study its properties. We show that at frequencies larger than 20 MHz and distances larger than 100 m, the standard far-field approximation for the horizontal polarizations of the field is always accurate at the 1% level.
Self-energy and self-force in the space-time of a thick cosmic string
NASA Astrophysics Data System (ADS)
Khusnutdinov, N. R.; Bezerra, V. B.
2001-10-01
We calculate the self-energy and self-force for an electrically charged particle at rest in the background of Gott-Hiscock cosmic string space-time. We find the general expression for the self-energy which is expressed in terms of the S matrix of the scattering problem. The self-energy continuously falls down outward from the string's center with the maximum at the origin of the string. The self-force is repulsive for an arbitrary position of the particle. It tends to zero in the string's center and also far from the string and it has a maximum value at the string's surface. The plots of the numerical calculations of the self-energy and self-force are shown.
monitoring la Soufrière de Guadeloupe phreatic system with muon tomography
NASA Astrophysics Data System (ADS)
Jourde, Kevin; Gibert, Dominique; Marteau, Jacques; de Bremond d'Ars, Jean; Ianigro, Jean-Christophe; Gardien, Serge; Girerd, Claude
2015-04-01
Muon tomography is a novel geophysics imaging technique that measures the flux of cosmic muons crossing geological bodies. Its attenuation is directly related to their thickness and density. On la Soufrière de Guadeloupe volcano, we could extract tiny particle flux fluctuations from the tomography signal of long-term acquisitions (a few months). We prove that atmospheric fluctuations or solar activity, which are the usual candidates for cosmic particles time modulations, cannot explain these changes leaving the volcanic dome phreatic system as the only explanation. Moreover the temporal trends we extracted from the different observation axes of our instrument show a good spatial and temporal correlation with events occuring at the surface of the volcano.
Cosmic-ray abundances of Sn, Te, Xe, and Ba nuclei measured on HEAO 3
NASA Technical Reports Server (NTRS)
Binns, W. R.; Israel, M. H.; Klarmann, J.; Fickle, R. K.; Waddington, C. J.; Garrard, T. L.; Krombel, K. E.; Stone, E. C.
1983-01-01
The results of an analysis of HEAO 3 Heavy Nuclei Experimental data covering 440 days of observations of Sn-Ba nuclei in cosmic rays are reported. The particles were detected by a Cernkov counter, and a Z-squared ceiling was calculated to normalize the histograms produced. The observed large abundance of Sn and Ba relative to other elements in the region of interest indicated a predominance of the s-process in the source of the particles. When account was taken of first ionization potential effects, the data indicated that the material could be solar system in origin. A source dominated by the r-process nucleosynthesis was ruled out at the 0.93 confidence level.
The energy distribution of very heavy cosmic ray nuclei within the penumbra at Palestine, Texas
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mathiesen, O.; Larsson, L.; Andersson, R.
1975-09-01
The low-energy end of the rigidity spectrum of cosmic ray nuclei with atomic numbers 7greater than or equal to18, recorded in a balloon flight conducted from Palestine, Texas, has been compared with a corresponding theoretical spectrum based on the computations by Shea and Smart. The two distributions are found to be in qualitative agreement with each other. The spread in apparent particle charge, caused by the theoretical distribution of particle velocity at Palestine, has been calculated for detectors with different response functions. The resulting structure of the predicted charge spectrum of iron group nuclei is found to be in goodmore » agreement with corresponding experimental data.« less
NASA Technical Reports Server (NTRS)
Zusmanovich, A. G.; Kryakunova, O. N.; Churunova, L. F.; Shvartsman, Y. E.
1985-01-01
A numerical model of the propagation of galactic cosmic rays in interplanetary space was constructed for the case when the modulation depth determined by the level of solar activity changed in time. Also the contribution of particle drift in the regular field was calculated, and the agreement with experimental data concerning the ratio of protons and electrons in two solar activity minima is shown.
DAMPE prototype and its beam test results at CERN
NASA Astrophysics Data System (ADS)
Wu, Jian; Hu, Yiming; Chang, Jin
The first Chinese high energy cosmic particle detector(DAMPE) aims to detect electron/gamma at the range between 5GeV and 10TeV in space. A prototype of this detector is made and tested using both cosmic muons and test beam at CERN. Energy and space resolution as well as strong separation power for electron and proton are shown in the results. The detector structure is illustrated as well.
High-Energy Cosmic Ray Self-Confinement Close to Extra-Galactic Sources.
Blasi, Pasquale; Amato, Elena; D'Angelo, Marta
2015-09-18
The ultrahigh-energy cosmic rays observed on the Earth are most likely accelerated in extra-Galactic sources. For the typical luminosities invoked for such sources, the electric current associated to the flux of cosmic rays that leave them is large. The associated plasma instabilities create magnetic fluctuations that can efficiently scatter particles. We argue that this phenomenon forces cosmic rays to be self-confined in the source proximity for energies E
Search for Cosmic-Ray Antiproton Origins and for Cosmological Antimatter with BESS
NASA Technical Reports Server (NTRS)
Yamamoto, A.; Mitchell, J. W.; Yoshimura, K.; Abe, K.; Fuke, H.; Haino, S.; Hams, T.; Hasegawa, M.; Horikoshi, A.; Itazaki, A.;
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).
Cosmic Rays as a Factor of Biosphere Evolution
NASA Astrophysics Data System (ADS)
Miroshnichenko, L. I.
2014-11-01
There are no doubts that the Earth's space environment in the past inevitably exerted direct and/or indirect influence [1--4] on the conditions of terrestrial life and biospheric evolution. Well-known cosmic factors are usually streams of cosmic dust and gas, comets and asteroids, cosmic rays (energetic particles of galactic and/or solar origin), interplanetary plasma (solar wind), and electromagnetic radiation of different energies, wavelengths, or frequencies. Of great interest are radiation conditions and their variations, especially in the remote past (over the geological time scales). The Sun, the most important and indispensable condition for the existence of the Earth's biosphere, is also a potential source of dangerous emissions. In continuation of (and in addition to) our review paper [3], below we summarize the observational data and results of theoretical works that have been carried out and/or published mainly after 2012. These studies are actually in the frontier region between the Astrobiology and Space Weather. Our main attention is paid to cosmic rays (CR) of galactic and solar origin (GCR and SCR, respectively).
X-ray Observations of Cosmic Ray Acceleration
NASA Technical Reports Server (NTRS)
Petre, Robert
2012-01-01
Since the discovery of cosmic rays, detection of their sources has remained elusive. A major breakthrough has come through the identification of synchrotron X-rays from the shocks of supernova remnants through imaging and spectroscopic observations by the most recent generation of X-ray observatories. This radiation is most likely produced by electrons accelerated to relativistic energy, and thus has offered the first, albeit indirect, observational evidence that diffusive shock acceleration in supernova remnants produces cosmic rays to TeV energies, possibly as high as the "knee" in the cosmic ray spectrum. X-ray observations have provided information about the maximum energy to which these shOCks accelerate electrons, as well as indirect evidence of proton acceleration. Shock morphologies measured in X-rays have indicated that a substantial fraction of the shock energy can be diverted into particle acceleration. This presentation will summarize what we have learned about cosmic ray acceleration from X-ray observations of supernova remnants over the past two decades.
Cosmic-ray antiprotons, positrons, and gamma rays from halo dark matter annihilation
NASA Technical Reports Server (NTRS)
Rudaz, S.; Stecker, F. W.
1988-01-01
The subject of cosmic ray antiproton production is reexamined by considering other choices for the nature of the Majorana fermion chi other than the photino considered in a previous article. The calculations are extended to include cosmic-ray positrons and cosmic gamma rays as annihilation products. Taking chi to be a generic higgsino or simply a heavy Majorana neutrino with standard couplings to the Z-zero boson allows the previous interpretation of the cosmic antiproton data to be maintained. In this case also, the annihilation cross section can be calculated independently of unknown particle physics parameters. Whereas the relic density of photinos with the choice of parameters in the previous paper turned out to be only a few percent of the closure density, the corresponding value for Omega in the generic higgsino or Majorana case is about 0.2, in excellent agreement with the value associated with galaxies and one which is sufficient to give the halo mass.
Transport of cosmic ray nuclei in various materials
NASA Technical Reports Server (NTRS)
Silberberg, R.; Tsao, C. H.; Letaw, J. R.
1988-01-01
Cosmic-ray heavy ions have become a concern in space radiation effects analyses. Heavy ions rapidly deposit energy and create dense ionization trails as they traverse materials. Collection of the free charge disrupts the operation of microelectronic circuits. This effect, called the single-event upset, can cause a loss of digital data. Passage of high linear energy transfer particles through the eyes has been observed by Apollo astronauts. These heavy ions have great radiobiological effectiveness and are the primary risk factor for leukemia induction on a manned Mars mission. Models of the transport of heavy cosmic-ray nuclei through materials depend heavily on our understanding of the cosmic-ray environment, nuclear spallation cross sections, and computer transport codes. Our group has initiated and pursued the development of a full capability for modeling these transport processes. A recent review of this ongoing effort is presented in Ref. 5. In this paper, we discuss transport methods and present new results comparing the attenuation of cosmic rays in various materials.
Cosmic ray albedo gamma rays from the quiet sun
NASA Technical Reports Server (NTRS)
Seckel, D.; Stanev, T.; Gaisser, T. K.
1992-01-01
We estimate the flux of gamma-rays that result from collisions of high energy galactic cosmic rays with the solar atmosphere. An important aspect of our model is the propagation of cosmic rays through the magnetic fields of the inner solar systems. We use diffusion to model propagation down to the bottom of the corona. Below the corona we trace particle orbits through the photospheric fields to determine the location of cosmic ray interactions in the solar atmosphere and evolve the resultant cascades. For our nominal choice of parameters, we predict an integrated flux of gamma rays (at 1 AU) of F(E(sub gamma) greater than 100 MeV) approximately = 5 x 10(exp -8)/sq cm sec. This can be an order of magnitude above the galactic background and should be observable by the Energetic Gamma Ray experiment telescope (EGRET).
Cosmic-ray transport in the heliosphere: A global perspective
NASA Astrophysics Data System (ADS)
Florinski, Vladimir
2013-02-01
Earth is shielded from the hazardous galactic radiation in the form or cosmic ray ions by the outwardly flow of the solar wind plasma and by the geomagnetic field. Understanding the effects of the global structure of the heliosphere on the transport of energetic charged particles remains an important challenge in space physics. The expanding bubble of the supersonic solar wind cools the populations of GeV ions that penetrate deeply into the interplanetary space. Beyond the solar wind lies the heliosheath that is believed to act as a long-term storage reservoir for the cosmic rays. The heliosheath and its magnetic field topology play an important role in modulating cosmic rays at large heliocentric distances. Understanding this role is crucial for interpreting the the puzzling Voyager spacecraft observations near the edge of the solar system.
NASA Astrophysics Data System (ADS)
Pierre Auger Collaboration; Abreu, P.; Aglietta, M.; Ahlers, M.; Ahn, E. J.; Albuquerque, I. F. M.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Antiči'c, T.; Aramo, C.; Arganda, E.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Badescu, A. M.; Balzer, M.; Barber, K. B.; Barbosa, A. F.; Bardenet, R.; Barroso, S. L. C.; Baughman, B.; Bäuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellétoile, A.; Bellido, J. A.; BenZvi, S.; Berat, C.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, F.; Blanco, M.; Bleve, C.; Blümer, H.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Brogueira, P.; Brown, W. C.; Bruijn, R.; Buchholz, P.; Bueno, A.; Buroker, L.; Burton, R. E.; Caballero-Mora, K. S.; Caccianiga, B.; Caramete, L.; Caruso, R.; Castellina, A.; Catalano, O.; Cataldi, G.; Cazon, L.; Cester, R.; Chauvin, J.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chirinos Diaz, J.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cook, H.; Cooper, M. J.; Coppens, J.; Cordier, A.; Coutu, S.; Covault, C. E.; Creusot, A.; Criss, A.; Cronin, J.; Curutiu, A.; Dagoret-Campagne, S.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; De Donato, C.; de Jong, S. J.; De La Vega, G.; de Mello Junior, W. J. M.; de Mello Neto, J. R. T.; De Mitri, I.; de Souza, V.; de Vries, K. D.; del Peral, L.; del Río, M.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Díaz Castro, M. L.; Diep, P. N.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; dos Anjos, J. C.; Dova, M. T.; D'Urso, D.; Dutan, I.; Ebr, J.; Engel, R.; Erdmann, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipčič, A.; Fliescher, S.; Fracchiolla, C. E.; Fraenkel, E. D.; Fratu, O.; Fröhlich, U.; Fuchs, B.; Gaior, R.; Gamarra, R. F.; Gambetta, S.; García, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gemmeke, H.; Ghia, P. L.; Giller, M.; Gitto, J.; Glass, H.; Gold, M. S.; Golup, G.; Gomez Albarracin, F.; Gómez Berisso, M.; Gómez Vitale, P. F.; Gonçalves, P.; Gonzalez, J. G.; Gookin, B.; Gorgi, A.; Gouffon, P.; Grashorn, E.; Grebe, S.; Griffith, N.; Grillo, A. F.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holmes, V. C.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huber, D.; Huege, T.; Insolia, A.; Ionita, F.; Italiano, A.; Jansen, S.; Jarne, C.; Jiraskova, S.; Josebachuili, M.; Kadija, K.; Kampert, K. H.; Karhan, P.; Kasper, P.; Katkov, I.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kelley, J. L.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapp, J.; Koang, D.-H.; Kotera, K.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kulbartz, J. K.; Kunka, N.; La Rosa, G.; Lachaud, C.; LaHurd, D.; Latronico, L.; Lauer, R.; Lautridou, P.; Le Coz, S.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Lopez Agüera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Lyberis, H.; Maccarone, M. C.; Macolino, C.; Maldera, S.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, J.; Marin, V.; Maris, I. C.; Marquez Falcon, H. R.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martínez Bravo, O.; Martraire, D.; Masías Meza, J. J.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mazur, P. O.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Mertsch, P.; Messina, S.; Meurer, C.; Meyhandan, R.; Mi'canovi'c, S.; Micheletti, M. I.; Minaya, I. A.; Miramonti, L.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morales, B.; Morello, C.; Moreno, E.; Moreno, J. C.; Mostafá, M.; Moura, C. A.; Muller, M. A.; Müller, G.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nhung, P. T.; Niechciol, M.; Niemietz, L.; Nierstenhoefer, N.; Nitz, D.; Nosek, D.; Nožka, L.; Oehlschläger, J.; Olinto, A.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Parente, G.; Parizot, E.; Parra, A.; Pastor, S.; Paul, T.; Pech, M.; Peķala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Petrera, S.; Petrolini, A.; Petrov, Y.; Pfendner, C.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Ponce, V. H.; Pontz, M.; Porcelli, A.; Privitera, P.; Prouza, M.; Quel, E. J.; Querchfeld, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rivera, H.; Rizi, V.; Roberts, J.; Rodrigues de Carvalho, W.; Rodriguez, G.; Rodriguez Cabo, I.; Rodriguez Martino, J.; Rodriguez Rojo, J.; Rodríguez-Frías, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Rouillé-d'Orfeuil, B.; Roulet, E.; Rovero, A. C.; Rühle, C.; Saftoiu, A.; Salamida, F.; Salazar, H.; Salesa Greus, F.; Salina, G.; Sánchez, F.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarkar, S.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, A.; Scholten, O.; Schoorlemmer, H.; Schovancova, J.; Schovánek, P.; Schröder, F.; Schuster, D.; Sciutto, S. J.; Scuderi, M.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Silva Lopez, H. H.; Sima, O.; 'Smiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Spinka, H.; Squartini, R.; Srivastava, Y. N.; Stanic, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Šuša, T.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Tapia, A.; Tartare, M.; Taşcău, O.; Tcaciuc, R.; Thao, N. T.; Thomas, D.; Tiffenberg, J.; Timmermans, C.; Tkaczyk, W.; Todero Peixoto, C. J.; Toma, G.; Tomankova, L.; Tomé, B.; Tonachini, A.; Torralba Elipe, G.; Travnicek, P.; Tridapalli, D. B.; Tristram, G.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van den Berg, A. M.; van Velzen, S.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Vicha, J.; Videla, M.; Villaseñor, L.; Wahlberg, H.; Wahrlich, P.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Westerhoff, S.; Whelan, B. J.; Widom, A.; Wieczorek, G.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Will, M.; Williams, C.; Winchen, T.; Wommer, M.; Wundheiler, B.; Yamamoto, T.; Yapici, T.; Younk, P.; Yuan, G.; Yushkov, A.; Zamorano Garcia, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.
2012-12-01
A thorough search for large-scale anisotropies in the distribution of arrival directions of cosmic rays detected above 1018 eV at the Pierre Auger Observatory is presented. This search is performed as a function of both declination and right ascension in several energy ranges above 1018 eV, and reported in terms of dipolar and quadrupolar coefficients. Within the systematic uncertainties, no significant deviation from isotropy is revealed. Assuming that any cosmic-ray anisotropy is dominated by dipole and quadrupole moments in this energy range, upper limits on their amplitudes are derived. These upper limits allow us to test the origin of cosmic rays above 1018 eV from stationary Galactic sources densely distributed in the Galactic disk and predominantly emitting light particles in all directions.
Advanced Cosmic-ray Composition Experiment for Space Station: ISS accommodation study
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wefel, John P.
1999-01-22
ACCESS--Advanced Cosmic-ray Composition Experiment for Space Station--was selected as a new Mission Concept under NRA 96-OSS-03, with the goal of combining calorimeter and transition radiation techniques to provide measurements of cosmic rays from Hydrogen through Nickel up to energies approaching the 'knee' in the cosmic ray all particle spectrum, plus providing measurements of the Z>28 (Ultra-Heavy) nuclei at all energies. An instrument to perform such an investigation is undergoing an ISS/STS Accommodation Study at JSC. The instrument concept, the mission plan, and the accommodation issues for an ISS attached payload which include, in part, the carrier, ISS Site, thermal control,more » power, data and operations are described and the current status of these issues, for an ACCESS Mission, is summarized.« less
Studies of the cosmic ray spectrum and large scale anisotropies with the KASCADE-Grande experiment
NASA Astrophysics Data System (ADS)
Chiavassa, A.; Apel, W. D.; Arteaga-Velázquez, J. C.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Cantoni, E.; Cossavella, F.; Curcio, C.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Fuchs, B.; Fuhrmann, D.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huber, D.; Huege, T.; Kampert, K.-H.; Kang, D.; Klages, H. O.; Link, K.; Łuczak, P.; Ludwig, M.; Mathes, H. J.; Mayer, H. J.; Melissas, M.; Milke, J.; Mitrica, B.; Morello, C.; Oehlschläger, J.; Ostapchenko, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schoo, S.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Zabierowski, J.
2014-08-01
KASCADE-Grande is an air shower observatory devoted to the detection of cosmic rays in the 1016 - 1018eV energy range. For each event the arrival direction, the total number of charged particles (Nch) and the total number of muons (Nμ), at detection level (i.e. 110 m a.s.l.), are measured. The detection of these observarbles, with high accuracy, allows the study of the primary spectrum, chemical composition and large scale anisotropies, that are the relevant informations to investigate the astrophysics of cosmic rays in this energy range. These studies are of main importance to deeply investigate the change of slope of the primary spectrum detected at ~ 4 × 1015 eV, also known as the knee, and to search for the transition from galactic to extra-galactic cosmic rays.
Constraining heavy dark matter with cosmic-ray antiprotons
NASA Astrophysics Data System (ADS)
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.
On Measuring Cosmic Ray Energy Spectra with the Rapidity Distributions
NASA Technical Reports Server (NTRS)
Bashindzhagyan, G.; Adams, J.; Chilingarian, A.; Drury, L.; Egorov, N.; Golubkov, S.; Korotkova, N.; Panasyuk, M.; Podorozhnyi, D.; Procqureur, J.
2000-01-01
An important goal of cosmic ray research is to measure the elemental energy spectra of galactic cosmic rays up to 10(exp 16) eV. This goal cannot be achieved with an ionization calorimeter because the required instrument is too massive for space flight. An alternate method will be presented. This method is based on measuring the primary particle energy by determining the angular distribution of secondaries produced in a target layer. The proposed technique can be used over a wide range of energies (10 (exp 11) -10 (exp 16) eV) and gives an energy resolution of 60% or better. Based on this technique, a conceptual design for a new instrument (KLEM) will be presented. Due to its light weight, this instrument can have a large aperture enabling the direct measurement of cosmic rays to 1016 eV.
Ultra High Energy Neutrinos and Cosmic Rays: a “Vision” for the next decade
NASA Astrophysics Data System (ADS)
Santangelo, A.
2007-04-01
Ultra High Energy Neutrinos, with energies from a few 1018 eV to beyond the decade of 1020 eV, and Cosmic Rays with E≥5×10 eV appear to be the only suitable messengers to explore the Universe at frontier energies, where radiation is expected to be produced under the most extreme physical conditions. Observations of these UHE particles will certainly provide new information on the sources and on the physical mechanisms able to accelerate these extreme messengers to macroscopic energies. Moreover, they might, also, provide evidence of yet unknown physics or of exotic particles, relics of the early Universe. To reach these goals, innovative experiments with larger effective aperture (A≥10 kmsr) and good understanding of systematic uncertainties (less than ˜ 10%) must be developed. The ground-based Pierre Auger Observatory, whose southern site is expected to be completed in Malargue, Argentina by the end of 2006, will surely provide, in the near future, a more solid observational scenario (Flux, Spectral shape, Composition) for UHE Cosmic Rays (UHECR). However, only space-based observatories can reach the effective area necessary to systematically explore the UHE Universe. In the present paper 1.) we present the Science Rationale behind UHE studies; 2.) we review the status of current experimental efforts, with main emphasis on the actual generation of space-based observatories; 3.) we briefly discuss the science goals, requirements, and R&D of a “next-generation” space-based mission for UHE observations. To develop such a challenging and innovative observatory for UHE particles, the ESA “Cosmic Vision 2015-2025” long term plan provides certainly an unique opportunity.
Development of a Portable Muon Witness System
DOE Office of Scientific and Technical Information (OSTI.GOV)
Aguayo Navarrete, Estanislao; Kouzes, Richard T.; Orrell, John L.
2011-01-01
Since understanding and quantifying cosmic ray induced radioactive backgrounds in copper and germanium are important to the MAJORANA DEMONSTRATOR, methods are needed for monitoring the levels of such backgrounds produced in materials being transported and processed for the experiment. This report focuses on work conducted at Pacific Northwest National Laboratory to develop a muon witness system as a one way of monitoring induced activities. The operational goal of this apparatus is to characterize cosmic ray exposure of materials. The cosmic ray flux at the Earth’s surface is composed of several types of particles, including neutrons, muons, gamma rays and protons.more » These particles induce nuclear reactions, generating isotopes that contribute to the radiological background. Underground, the main mechanism of activation is by muon produced spallation neutrons since the hadron component of cosmic rays is removed at depths greater than a few tens of meters. This is a sub-dominant contributor above ground, but muons become predominant in underground experiments. For low-background experiments cosmogenic production of certain isotopes, such as 68Ge and 60Co, must be accounted for in the background budgets. Muons act as minimum ionizing particles, depositing a fixed amount of energy per unit length in a material, and have a very high penetrating power. Using muon flux measurements as a “witness” for the hadron flux, the cosmogenic induced activity can be quantified by correlating the measured muon flux and known hadronic production rates. A publicly available coincident muon cosmic ray detector design, the Berkeley Lab Cosmic Ray Detector (BLCRD), assembled by Juniata College, is evaluated in this work. The performance of the prototype is characterized by assessing its muon flux measurements. This evaluation is done by comparing data taken in identical scenarios with other cosmic ray telescopes. The prototype is made of two plastic scintillator paddles with associated electronics to measure energy depositions in coincidence in the two paddles. For this particular application of the prototype, the measurements performed concentrated on a broad investigation of the dependence of the muon flux on depth underground. These tests were conducted inside at Building 3420/1307 and underground at Building 3425 at the Pacific Northwest National Laboratory. The second half of this report analyzes modifications to the electronics of the BLCRD to make this detector portable. Among other modifications, a battery powered version of these electronics is proposed for the final Muon Witness design.« less
Shielding of manned space vehicles against protons and alpha particles
NASA Technical Reports Server (NTRS)
Alsmiller, R. G., Jr.; Santoro, R. T.; Barish, J.; Claiborne, H. C.
1972-01-01
The available information on the shielding of manned space vehicles against protons and alpha particles is summarized. The emphasis is placed on shielding against Van Allen belt protons and against solar-flare protons and alpha particles, but information on shielding against galactic cosmic rays is also presented. The approximation methods for use by nonexperts in the space shielding field are those that are standard in the space shielding literature.
A study of heavy-heavy nuclear reactions. [nuclear research/nuclear particles
NASA Technical Reports Server (NTRS)
Khandelwal, G. S.
1975-01-01
Calculations are presented for the reaction products in high energy collisions and of the atmospheric transport of particles such as protons, neutrons and other nucleons. The magnetic moments of charmed baryons are examined. Total cross sections which are required for cosmic heavy ion transport and shielding studies are also examined.
Study of the cosmogenic activation in NaI(Tl) crystals within the ANAIS experiment
NASA Astrophysics Data System (ADS)
Villar, P.; Amaré, J.; Cebrián, S.; Coarasa, I.; García, E.; Martínez, M.; Oliván, M. A.; Ortigoza, Y.; Ortiz de Solórzano, A.; Puimedón, J.; Sarsa, M. L.; Villar, J. A.
2018-03-01
The direct detection of galactic dark matter particles requires ultra-low background conditions. NaI(Tl) crystals are applied in the search for these dark matter particles through their interactions in the detector by measuring the scintillation signal produced. The production of long-lived isotopes in materials due to the exposure to cosmic rays on Earth’s surface can be an hazard for these ultra-low background demanding experiments, typically performed underground. Therefore, production rates of cosmogenic isotopes in all the materials present in the experimental set-up, as well as the corresponding cosmic rays exposure history, must be both well-known in order to assess the relevance of this effect in the achievable sensitivity of a given experiment. Here, analysis of the cosmogenic studies developed from the ANAIS experiment NaI(Tl) detectors are presented. Installed inside a convenient shielding at the Canfranc Underground Laboratory just after finishing surface exposure to cosmic rays and thanks to the prompt data taking developed, identification and quantification of isotopes with half-lives of the order of tens of days were allowed, and thanks to the long-term operation of the detectors long-lived isotopes have been also identified and quantified. Main results for the activation yields of iodine and tellurium isotopes, 22Na, 113Sn, 109Cd, and tritium are presented in this work, together with the estimate of the production rates for their activation by cosmic nucleons while on Earth’s surface based on a selection of excitation functions over the entire energy range of cosmic nucleons.
Thunderstorm observations by air-shower radio antenna arrays
NASA Astrophysics Data System (ADS)
Apel, W. D.; Arteaga, J. C.; Bähren, L.; Bekk, K.; Bertaina, M.; Biermann, P. L.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Buchholz, P.; Buitink, S.; Cantoni, E.; Chiavassa, A.; Daumiller, K.; de Souza, V.; di Pierro, F.; Doll, P.; Ender, M.; Engel, R.; Falcke, H.; Finger, M.; Fuhrmann, D.; Gemmeke, H.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Horneffer, A.; Huber, D.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Krömer, O.; Kuijpers, J.; Link, K.; Łuczak, P.; Ludwig, M.; Mathes, H. J.; Melissas, M.; Morello, C.; Nehls, S.; Oehlschläger, J.; Palmieri, N.; Pierog, T.; Rautenberg, J.; Rebel, H.; Roth, M.; Rühle, C.; Saftoiu, A.; Schieler, H.; Schmidt, A.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.; Zensus, J. A.
2011-10-01
Relativistic, charged particles present in extensive air showers (EAS) lead to a coherent emission of radio pulses which are measured to identify the shower initiating high-energy cosmic rays. Especially during thunderstorms, there are additional strong electric fields in the atmosphere, which can lead to further multiplication and acceleration of the charged particles and thus have influence on the form and strength of the radio emission. For a reliable energy reconstruction of the primary cosmic ray by means of the measured radio signal it is very important to understand how electric fields affect the radio emission. In addition, lightning strikes are a prominent source of broadband radio emissions that are visible over very long distances. This, on the one hand, causes difficulties in the detection of the much lower signal of the air shower. On the other hand the recorded signals can be used to study features of the lightning development. The detection of cosmic rays via the radio emission and the influence of strong electric fields on this detection technique is investigated with the LOPES experiment in Karlsruhe, Germany. The important question if a lightning is initiated by the high electron density given at the maximum of a high-energy cosmic-ray air shower is also investigated, but could not be answered by LOPES. But, these investigations exhibit the capabilities of EAS radio antenna arrays for lightning studies. We report about the studies of LOPES measured radio signals of air showers taken during thunderstorms and give a short outlook to new measurements dedicated to search for correlations of lightning and cosmic rays.
Bonolis, Luisa
2014-07-01
During the 1920s and 1930s, Italian physicists established strong relationships with scientists from other European countries and the United States. The career of Bruno Rossi, a leading personality in the study of cosmic rays and an Italian pioneer of this field of research, provides a prominent example of this kind of international cooperation. Physics underwent major changes during these turbulent years, and the traditional internationalism of physics assumed a more institutionalized character. Against this backdrop, Rossi's early work was crucial in transforming the study of cosmic rays into a branch of modern physics. His friendly relationships with eminent scientists--notably Enrico Fermi, Walther Bothe, Werner Heisenberg, Hans Bethe, and Homi Bhabha--were instrumental both for the exchange of knowledge about experimental practices and theoretical discussions, and for attracting the attention of physicists such as Arthur Compton, Louis Leprince-Ringuet, Pierre Auger and Patrick Blackett to the problem of cosmic rays. Relying on material from different archives in Europe and the United States, this case study aims to provide a glimpse of the intersection between national and international dimensions during the 1930s, at a time when the study of cosmic rays was still very much in its infancy, strongly interlaced with nuclear physics, and full of uncertain, contradictory, and puzzling results. Nevertheless, as a source of high-energy particles it became a proving ground for testing the validity of the laws of quantum electrodynamics, and made a fundamental contribution to the origins of particle physics.
Matthiä, Daniel; Hassler, Donald M; de Wet, Wouter; Ehresmann, Bent; Firan, Ana; Flores-McLaughlin, John; Guo, Jingnan; Heilbronn, Lawrence H; Lee, Kerry; Ratliff, Hunter; Rios, Ryan R; Slaba, Tony C; Smith, Michael; Stoffle, Nicholas N; Townsend, Lawrence W; Berger, Thomas; Reitz, Günther; Wimmer-Schweingruber, Robert F; Zeitlin, Cary
2017-08-01
The radiation environment at the Martian surface is, apart from occasional solar energetic particle events, dominated by galactic cosmic radiation, secondary particles produced in their interaction with the Martian atmosphere and albedo particles from the Martian regolith. The highly energetic primary cosmic radiation consists mainly of fully ionized nuclei creating a complex radiation field at the Martian surface. This complex field, its formation and its potential health risk posed to astronauts on future manned missions to Mars can only be fully understood using a combination of measurements and model calculations. In this work the outcome of a workshop held in June 2016 in Boulder, CO, USA is presented: experimental results from the Radiation Assessment Detector of the Mars Science Laboratory are compared to model results from GEANT4, HETC-HEDS, HZETRN, MCNP6, and PHITS. Charged and neutral particle spectra and dose rates measured between 15 November 2015 and 15 January 2016 and model results calculated for this time period are investigated. Copyright © 2017 The Committee on Space Research (COSPAR). All rights reserved.
Beryllium-10 and Aluminum-26 in Individual Cosmic Spherules from Antarctica
NASA Technical Reports Server (NTRS)
Nishiizumi, K.; Arnold, J. R.; Brownlee, D. E.; Caffee, M. W.; Finkel, R. C.; Harvey, R. P.
1995-01-01
We present data for the cosmogenic nuclides Be-10 and A-26 in a suite of 24 extraterrestrial spherules, collected from Antarctic moraines and deep sea sediments. All of the 10 large spherules collected in glacial till at Lewis Cliff are extraterrestrial. As in earlier work, the great majority of particles show prominent solar cosmic-ray (SCR) production of Al-26, indicating bombardment ages on the order of 106 years or even longer. These long ages are in direct contradiction to model ages for small particles in the inner Solar System and may require reconsideration of models of small particle lifetimes. A small fraction of the particles so far measured (6/42) possess cosmogenic radionuclide patterns consistent with predictions for meteoroid spall droplets. We believe that most of the spherules were bombarded in space primarily as bodies not much larger than their present size. The content of in situ produced Be-10 and Al-26 in quartz pebbles in the same moraine suggests that these spherules may have on average a significant terrestrial age.
Analysis of LEAM experiment response to charged particles
NASA Technical Reports Server (NTRS)
Perkins, D.
1976-01-01
The objectives of the Lunar Ejecta and Meteorites Experiment (LEAM) were to measure the long-term variations in cosmic dust influx rates and the extent and nature of the lunar ejecta. While analyzing these characteristics in the data, it was discovered that a majority of the events could not be associated with hypervelocity particle impacts of the type usually identified with cosmic dust, but could only be correlated with the lunar surface and local sun angle. The possibility that charged particles could be incident on the sensors led to an analysis of the electronics to determine if such signals could cause the large pulse height analysis (PHA) signals. A qualitative analysis of the PHA circuit showed that an alternative mode of operation existed if the input signal were composed of pulses with pulse durations very long compared to the durations for which it was designed. This alternative mode would give large PHA outputs even though the actual input amplitudes were small. This revelation led to the examination of the sensor and its response to charged particles to determine the type of signals that could be expected.
Bioeffectiveness of Cosmic Rays Near the Earth Surface
NASA Astrophysics Data System (ADS)
Belisheva, N. K.
2014-10-01
Experimental studies of the dynamics of morphological and functional state of the diverse biosystems (microflora, plant Maranta leuconeura «Fascinator», cell cultures, human peripheral blood, the human body ) have shown that geocosmical agents modulated the functional state of biological systems Belisheva 2006; Belisheva et all 2007 ) . First time on the experimental data showed the importance of the increase in the fluxes of solar cosmic rays (CRs ) with high energies (Belisheva et all 2002; 2012; Belisheva, Lammer, Biernat, 2004) and galactic cosmic ray variations (Belisheva et al, 2005; 2006; Vinnichenko Belisheva, 2009 ) near the Earth surface for the functional state of biosystems. The evidence of the presence of the particles with high bioeffectiveness in the secondary cosmic rays was obtained by simulating the particle cascades in the atmosphere, performed by using Geant4 (Planetocosmics, based on the Monte Carlo code (Maurchev et al, 2011), and experimental data, where radiobiological effects of cosmic rays were revealed. Modeling transport of solar protons through the Earth's atmosphere, taking into account the angular and energy distributions of secondary particles in different layers of the atmosphere, allowed us to estimate the total neutron flux during three solar proton events, accompanied by an increase in the intensity of the nucleon component of secondary cosmic rays - Ground Level Enhancement GLE (43, 44, 45) in October 1989 (19, 22, 24 October). The results obtained by simulation were compared with the data of neutron monitors and balloon measurements made during solar proton events. Confirmation of the neutron fluxes near the Earth surface during the GLE (43, 44, 45) were obtained in the experiments on the cellular cultures (Belisheva et al. 2012). A direct evidence of biological effects of CR has been demonstrated in experiments with three cellular lines growing in culture during three events of Ground Level Enhancement (GLEs) in the neutron count rate detected by ground-based neutron monitor in October, 1989. Various phenomena associated with DNA lesion on the cellular level demonstrate coherent dynamics of radiation effects in all cellular lines coincident with the time of arrival of high-energy solar particles to the near-Earth space and with the main peak in GLE. These results were obtained in the course of six separate experiments, with partial overlapping of the time of previous and subsequent experiments, which started and finished in the quiet period of solar activity (SA).A significant difference between the values of multinuclear cells in all cellular lines in the quiet period and during GLE events indicates that the cause of radiation effects in the cell cultures is an exposure of cells to the secondary solar CR near the Earth's surface. Calculations of the total flux of particles with the greatest bioeffectiveness and ambient dose equivalent neutron fluxes in different energy ranges showed that taking into account the duration of all cases GLE (19, 22, 24 October 1989), the cellular cultures were irradiated by ambient dose equivalent equal 217 microSv cm^2, which corresponds to a little less than half of the radiation dose astronauts during the day in Earth orbit (Reitz et.all, 2005; Semkova et al, 2012) and more than the average dose received by pilots per flying hour in 1997 (2.96 mSv h -1) (Langner et all, 2004). These doses are sufficient to cause genetic damages as material for the variability and the subsequent evolution of biological systems. Results of experiments conducted on cellular cultures during a great solar proton events showed that the main damages of the genetic material in the cellular nuclei appeared with increasing of the spectral hardness of solar protons that corresponded to the arrival of the particles with energies > 850 MeV in the near Earth space. The analysis shows that the prevalence of certain forms of congenital malformations in children (CDF) at high latitudes was associated with increases in fluxes of CR and with solar proton events accompanied by GLE cases. Furthermore, the frequency of incidence of all forms of congenital malformations in children increased in the years with low solar activity associated with an increase in the intensity of Cosmic rays. We found that the incidence of certain diseases of children and adults in Arctic region were higher in the year with high intensity of cosmic rays ( Belisheva, Talykova, Melnik, 2011). The results show that the GLE cases, associated with increase in particle fluxes of hard energy spectrum, can trigger DNA damage in human cells, as in the case of cellular cultures during solar proton events. These results are of basic importance for the recognition of the biological effectiveness of the background fluctuations of Cosmic rays
Investigation of soft component in cosmic ray detection
NASA Astrophysics Data System (ADS)
Oláh, László; Varga, Dezső
2017-07-01
Cosmic ray detection is a research area which finds various applications in tomographic imaging of large size objects. In such applications, the background sources which contaminate cosmic muon signal require a good understanding of the creation processes, as well as reliable simulation frameworks with high predictive power are needed. One of the main background source is the ;soft component;, that is electrons and positrons. In this paper a simulation framework based on GEANT4 has been established to pin down the key features of the soft component. We have found that the electron and positron flux shows a remarkable invariance against various model parameters including the muon emission altitude or primary particle energy distribution. The correlation between simultaneously arriving particles have been quantitatively investigated, demonstrating that electrons and positrons tend to arrive within a close distance and with low relative angle. This feature, which is highly relevant for counting detectors, has been experimentally verified under open sky and at shallow depth underground. The simulation results have been compared to existing other measurements as well as other simulation programs.
Pioneer 10 at Silver Au Describes Sun's atmosphere
NASA Technical Reports Server (NTRS)
1981-01-01
Almost 4 billion kilometers from the Sun, Pioneer 10's findings paint a detailed picture of the solar atmosphere. The heliosphere is now believed to be a huge magnetic bubble created by the solar wind and gets its tear-shape from streamlining due to the motion of the solar system through the interstellar gas. The skin of the bubble, the region between stellar and interstellar gas, is believed to lie between 50 and 100 AU from the Sun. The solar wind drags the Sun's magnetic field with it. The bubble, probably extends far beyond Pluto, and is believed to breathe, expanding and contracting like a giant cosmic lung with each 11 year cycle. The most recent findings show that as storms on the Sun build up toward maximum solar activity, they send out shock waves throughout the bubble which cause ripples. This long lived solar storm turbulence accelerates low energy cosmic ray particles coming in from the galaxy, deflecting them out of the solar system, and shielding the planets. As distance from the Sun increases, more and more cosmic ray particles penetrate the heliosphere.
THE HIGHEST-ENERGY COSMIC RAYS CANNOT BE DOMINANTLY PROTONS FROM STEADY SOURCES
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fang, Ke; Kotera, Kumiko
The bulk of observed ultrahigh-energy cosmic rays could be light or heavier elements and originate from an either steady or transient population of sources. This leaves us with four general categories of sources. Energetic requirements set a lower limit on single-source luminosities, while the distribution of particle arrival directions in the sky sets a lower limit on the source number density. The latter constraint depends on the angular smearing in the skymap due to the magnetic deflections of the charged particles during their propagation from the source to the Earth. We contrast these limits with the luminosity functions from surveysmore » of existing luminous steady objects in the nearby universe and strongly constrain one of the four categories of source models, namely, steady proton sources. The possibility that cosmic rays with energy >8 × 10{sup 19} eV are dominantly pure protons coming from steady sources is excluded at 95% confidence level, under the safe assumption that protons experience less than 30° magnetic deflection on flight.« less