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1

How to Detect Cosmic Rays Learning Objectives  

E-print Network

1 CRaTER: How to Detect Cosmic Rays Learning Objectives: · The students will be able to explain two examples of a cosmic ray detector. · Students will learn how cosmic rays can affect us here on Earth. The sources of particle radiation can be radioactive materials, like uranium, or cosmic rays. (See picture

Christian, Eric

2

How to Detect Cosmic Rays  

NSDL National Science Digital Library

In this lesson on cosmic rays, students will explain two examples of a cosmic ray detector. Includes information about student preconceptions and a demonstration that requires a geiger counter and optional access to a small radioactive source that emits energetic helium nuclei (alpha particles), e.g., the mineral the mineral autunite, which contains uranium. This is activity two of four from The Cosmic Ray Telescope for the Effects of Radiation (CRaTER).

2012-08-03

3

30TH INTERNATIONAL COSMIC RAY CONFERENCE Radio Detection of UltraHigh Energy Cosmic Rays  

E-print Network

30TH INTERNATIONAL COSMIC RAY CONFERENCE Radio Detection of Ultra­High Energy Cosmic Rays HEINO from cosmic rays, confirmed the geosynchrotron effect for extensive air showers, and provided a good rays and the usage of the LOFAR radio telescope (and later the SKA) as a cosmic ray detector. Here

Falcke, Heino

4

Detection of cosmic neutrino clustering by cosmic ray spectra  

E-print Network

We propose a method to investigate the scenario that cosmic relic neutrinos are highly clustered around stars and galaxies, or dark-matter clusters, rather than uniformly distributed in the universe. Such a scenario can be detected or constrained by the interaction of high energy cosmic ray protons and nuclei with the cosmic neutrinos. There should be observable signature in the energy spectra of cosmic ray protons and nuclei for a neutrino clustering factor beyond $10^{13}$. We provide a relation on the signature onset positions between proton and nuclei spectra, and discuss possible support from existing experiments. It is also suggested that the relative abundance of cosmic ray nuclei may detect or constrain the cosmic neutrinos with smaller clustering.

W-Y. P. Hwang; Bo-Qiang Ma

2005-02-18

5

Research Concerning Detection of Cosmic Rays  

NASA Astrophysics Data System (ADS)

Throughout my academic career at Loyola I have carried out research with the Loyola University Cosmic Event Detection System concerning the possibility of detection of ultra high energy cosmic rays (UHECRs) based on radio meteor scattering methods. This research was furthered through summer internships and research fellowships at Adler Planetarium Chicago and Stony Brook University in New York. At Adler Planetarium we used a helium balloon carrying a Geiger counter and other equipment to record the cosmic ray flux at various points in the atmosphere. The results clearly show the flux depends on the atmospheric density. At Stony Brook University I studied their advanced system for detecting cosmic rays in similar manner to radio meteor scattering principles. Research there focused on detection algorithms and also on the possibility of utilizing Digital Tv (DTv) signals for further research. Through the research a solid understanding of cosmic rays was formed including topics such as origins and energy scales of cosmic rays, both of which pose unanswered questions. )

Grady, Maxwell; Cunningham, John; Kuhlmann, Steve; Spinka, Hal; Underwood, Dave; Hammergren, Mark

2010-02-01

6

Student Projects in Cosmic Ray Detection  

NASA Astrophysics Data System (ADS)

The Alberta Large-area Time-coincidence Array (ALTA) study has been in existence for about 10 years under the direction of Jim Pinfold of the Centre for Particle Physics at the University of Alberta. The purpose of the ALTA project is to involve Alberta high schools, and primarily their physics classes, to assist in the detection of the presence of cosmic ray bursts in different Alberta locations. These cosmic rays involve highspeed elementary particles, many from far outside our solar system and even from outside our galaxy. These particles collide with the particles in our atmosphere, break up these molecules into rather exotic elementary particles which often reach the surface of the Earth and can be detected by fairly simple equipment. One of the objectives of ALTA is to determine the nature of some of the most energetic cosmic ray particles whose origin is still not known. Recently 2the Pierre Auger Collaboration has confirmed that the highest energy cosmic rays appear to be coming from nearby galaxies. The mechanism for their production is still not well understood.

Brouwer, W.; Pinfold, J.; Soluk, R.; McDonough, B.; Pasek, V.; Bao-shan, Zheng

2009-11-01

7

Cosmic rays  

NASA Astrophysics Data System (ADS)

The book presents a historical review of cosmic ray physics from the time of the discovery of cosmic rays up to the early 1950s, when accelerator experiments began to replace cosmic ray observations in the study of nuclear interactions at all but the highest energies. The discovery of radiation which constantly acts to produce atmospheric ionization and the demonstration of the extraterrestrial origin of this radiation are discussed, and studies leading to the elucidation of the nature of the primary radiation are reviewed. Attention is then given to studies of cosmic rays in the stratosphere, geomagnetic effects on cosmic rays, and cosmic ray showers. Discoveries of elementary particles in cosmic rays are discussed including positrons, muons and pions, and nuclear interactions occurring in cosmic rays are examined. Consideration is also given to spatial and temporal variations in cosmic ray intensity and their implications for the astrophysical origin of cosmic rays.

Dorman, I. V.

8

Optimal Cosmic-Ray Detection for Nondestructive Read Ramps  

NASA Astrophysics Data System (ADS)

Cosmic rays are a known problem in astronomy, causing both loss of data and data inaccuracy. The problem becomes even more extreme when considering data from a high-radiation environment, such as in orbit around Earth or outside the Earth''s magnetic field altogether, unprotected, as will be the case for the James Webb Space Telescope (JWST). For JWST, all the instruments employ nondestructive readout schemes. The most common of these will be ""up the ramp"" sampling, where the detector is read out regularly during the ramp. We study three methods to correct for cosmic rays in these ramps: a two-point difference method, a deviation from the fit method, and a y-intercept method. We apply these methods to simulated nondestructive read ramps with single-sample groups and varying combinations of flux, number of samples, number of cosmic rays, cosmic-ray location in the exposure, and cosmic-ray strength. We show that the y-intercept method is the optimal detection method in the read-noise-dominated regime, while both the y-intercept method and the two-point difference method are best in the photon-noise-dominated regime, with the latter requiring fewer computations.

Anderson, Rachel E.; Gordon, Karl D.

2011-10-01

9

Optimal Cosmic-Ray Detection for Nondestructive Read Ramps  

E-print Network

Cosmic rays are a known problem in astronomy, causing both loss of data and data inaccuracy. The problem becomes even more extreme when considering data from a high-radiation environment, such as in orbit around Earth or outside the Earth's magnetic field altogether, unprotected, as will be the case for the James Webb Space Telescope (JWST). For JWST, all the instruments employ nondestructive readout schemes. The most common of these will be "up the ramp" sampling, where the detector is read out regularly during the ramp. We study three methods to correct for cosmic rays in these ramps: a two-point difference method, a deviation from the fit method, and a y-intercept method. We apply these methods to simulated nondestructive read ramps with single-sample groups and varying combinations of flux, number of samples, number of cosmic rays, cosmic-ray location in the exposure, and cosmic-ray strength. We show that the y-intercept method is the optimal detection method in the read-noise-dominated regime, while both...

Anderson, Rachel E

2011-01-01

10

COSMIC-RAY MUON TOMOGRAPHY AND ITS APPLICATION TO THE DETECTION OF HIGH-Z MATERIALS  

E-print Network

COSMIC-RAY MUON TOMOGRAPHY AND ITS APPLICATION TO THE DETECTION OF HIGH-Z MATERIALS Konstantin. This allowed us to develop a technique which uses multiple scattering of cosmic-ray muons to detect shielded, 2]. The technique is based on the detection of the increased scattering of cosmic-ray muons

Kurien, Susan

11

Student Projects in Cosmic Ray Detection  

ERIC Educational Resources Information Center

The Alberta Large-area Time-coincidence Array (ALTA) study has been in existence for about 10 years under the direction of Jim Pinfold of the Centre for Particle Physics at the University of Alberta. The purpose of the ALTA project is to involve Alberta high schools, and primarily their physics classes, to assist in the detection of the presence

Brouwer, W.; Pinfold, J.; Soluk, R.; McDonough, B.; Pasek, V.; Bao-shan, Zheng

2009-01-01

12

Detecting cosmic rays with the LOFAR radio telescope  

NASA Astrophysics Data System (ADS)

The low frequency array (LOFAR), is the first radio telescope designed with the capability to measure radio emission from cosmic-ray induced air showers in parallel with interferometric observations. In the first ~2 years of observing, 405 cosmic-ray events in the energy range of 1016-1018 eV have been detected in the band from 30-80 MHz. Each of these air showers is registered with up to ~1000 independent antennas resulting in measurements of the radio emission with unprecedented detail. This article describes the dataset, as well as the analysis pipeline, and serves as a reference for future papers based on these data. All steps necessary to achieve a full reconstruction of the electric field at every antenna position are explained, including removal of radio frequency interference, correcting for the antenna response and identification of the pulsed signal.

Schellart, P.; Nelles, A.; Buitink, S.; Corstanje, A.; Enriquez, J. E.; Falcke, H.; Frieswijk, W.; Hrandel, J. R.; Horneffer, A.; James, C. W.; Krause, M.; Mevius, M.; Scholten, O.; ter Veen, S.; Thoudam, S.; van den Akker, M.; Alexov, A.; Anderson, J.; Avruch, I. M.; Bhren, L.; Beck, R.; Bell, M. E.; Bennema, P.; Bentum, M. J.; Bernardi, G.; Best, P.; Bregman, J.; Breitling, F.; Brentjens, M.; Broderick, J.; Brggen, M.; Ciardi, B.; Coolen, A.; de Gasperin, F.; de Geus, E.; de Jong, A.; de Vos, M.; Duscha, S.; Eislffel, J.; Fallows, R. A.; Ferrari, C.; Garrett, M. A.; Griemeier, J.; Grit, T.; Hamaker, J. P.; Hassall, T. E.; Heald, G.; Hessels, J. W. T.; Hoeft, M.; Holties, H. A.; Iacobelli, M.; Juette, E.; Karastergiou, A.; Klijn, W.; Kohler, J.; Kondratiev, V. I.; Kramer, M.; Kuniyoshi, M.; Kuper, G.; Maat, P.; Macario, G.; Mann, G.; Markoff, S.; McKay-Bukowski, D.; McKean, J. P.; Miller-Jones, J. C. A.; Mol, J. D.; Mulcahy, D. D.; Munk, H.; Nijboer, R.; Norden, M. J.; Orru, E.; Overeem, R.; Paas, H.; Pandey-Pommier, M.; Pizzo, R.; Polatidis, A. G.; Renting, A.; Romein, J. W.; Rttgering, H.; Schoenmakers, A.; Schwarz, D.; Sluman, J.; Smirnov, O.; Sobey, C.; Stappers, B. W.; Steinmetz, M.; Swinbank, J.; Tang, Y.; Tasse, C.; Toribio, C.; van Leeuwen, J.; van Nieuwpoort, R.; van Weeren, R. J.; Vermaas, N.; Vermeulen, R.; Vocks, C.; Vogt, C.; Wijers, R. A. M. J.; Wijnholds, S. J.; Wise, M. W.; Wucknitz, O.; Yatawatta, S.; Zarka, P.; Zensus, A.

2013-12-01

13

The Renaissance of Radio Detection of Cosmic Rays  

NASA Astrophysics Data System (ADS)

Nearly 50 years ago, the first radio signals from cosmic ray air showers were detected. After many successful studies, however, research ceased not even 10 years later. Only a decade ago, the field was revived with the application of powerful digital signal processing techniques. Since then, the detection technique has matured, and we are now in a phase of transition from small-scale experiments accessing energies below 10 18 eV to experiments with a reach for energies beyond 10 19 eV. We have demonstrated that air shower radio signals carry information on both the energy and the mass of the primary particle, and current experiments are in the process of quantifying the precision with which this information can be accessed. All of this rests on solid understanding of the radio emission processes which can be interpreted as a coherent superposition of geomagnetic emission, Askaryan charge-excess radiation, and Cherenkov-like coherence effects arising in the density gradient of the atmosphere. In this article, I highlight the "state of the art" of radio detection of cosmic rays and briefly discuss its perspectives for the next few years.

Huege, Tim

2014-10-01

14

Cosmic Ray Inspection and Passive Tomography for SNM Detection  

SciTech Connect

The Cosmic Ray Inspection and Passive Tomography (CRIPT) project has recently started investigating the detection of illicit Special Nuclear Material in cargo using cosmic ray muon tomography and complementary neutron detectors. We are currently performing simulation studies to help with the design of small scale prototypes. Based on the prototype tests and refined simulations, we will determine whether the muon tracking system for the full scale prototype will be based on drift chambers or extruded scintillator trackers. An analysis of the operations of the Port of Montreal has determined how long muon scan times should take if all or a subset of the cargo is to be screened. As long as the throughput of the muon system(s) is equal to the rate at which containers are unloaded from ships, the impact on port operations would not be great if a muon scanning stage were required for all cargo. We also show preliminary simulation results indicating that excellent separation between Al, Fe and Pb is possible under ideal conditions. The discrimination power is reduced but still significant when realistic momentum resolution measurements are considered.

Armitage, John; Oakham, Gerald [Department of Physics, Carleton University, 1125 Colonel By Drive, Ottawa, ON, K1S 5B6 (Canada); Bryman, Douglas [Advanced Applied Physics Solutions, 4004 Westbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Cousins, Thomas; Noeel, Scott [International Safety Research, 38 Colonnade Rd. N. Ottawa, ON, K2E 7J6 (Canada); Gallant, Grant [Canadian Border Services Agency, Laboratory and Scientific Services Directorate, 79 Bentley Avenue, Ottawa, ON, K2E 6T7 (Canada); Jason, Andrew [Los Alamos National Laboratories, MS H817, Los Alamos National Laboratory, Los Alamos, NM, USA 87544 (United States); Jonkmans, Guy [Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, ON, K0J 1J0 (Canada); Stocki, Trevor J. [Radiation Protection Bureau, Health Canada, 775 BrookfieldRd, A.L. 6302D1, Ottawa, ON, K1A 1C1 (Canada); Waller, David [Defence Research and Development Canada-Ottawa, 3701 Carling Avenue, Ottawa, ON, K1A 0Z4 (Canada)

2009-12-02

15

Feasibility of cosmic-ray muon intensity measurements for tunnel detection  

Microsoft Academic Search

Subsurface cosmic-ray muon intensity depends on the amount of material above the point of reference and is therefore influenced by anomalies in rock density. Because such anomalies might be caused by geological structures (e.g. ore bodies), cosmic-ray intensity measurements have been used for geophysical exploration. Recently, cosmic-ray muon intensity measurements have been also proposed as a method to detect tunnels.

Aivars Celmins

1990-01-01

16

Radio detection of ultra high energy cosmic rays and neutrinos  

NASA Astrophysics Data System (ADS)

Air showers produced in the interactions of cosmic rays and neutrinos produce radio frequency signals. In the atmosphere the dominant mechanism is geosynchrotron emission, and in dense media such as ice the Askaryan mechanism leads to coherent impulsive Cherenkov emission. Ground-based antenna arrays, balloon-borne interferometers, and buried arrays have been deployed to exploit this mechanism. The status of observations using this technique will be reviewed, and the prospects for future experiments will be discussed.

Beatty, James J.

2013-02-01

17

Cosmic Rays  

NSDL National Science Digital Library

This series of web pages gives an elementary discussion of cosmic rays, followed by sections on high energy particles in the universe and high-energy particles from the Sun. It describes the existence particles whose velocity approaches that of light, their probable sources, and their measurement. This is part of a large work, "The Exploration of the Earth's Magnetosphere", that gives a non-mathematical introduction to planetary and solar magnetic fields, space weather, aurora, and charged particle motion. A Spanish translation is available.

Stern, David

2005-04-27

18

Cosmic rays  

SciTech Connect

The fundamental characteristics of cosmic rays (CRs) and the history of CR studies are discussed in a general review. Chapters are devoted to the early days of CR observations, the identification of CRs, the effect of the geomagnetic field, solar particles, Galactic CRs, the CR energy spectrum, and clues from subatomic physics. Consideration is given to the origin of CRs, CRs with little or no mass, the subnuclear world, and applications of CR research (C-14 dating and studies of interplanetary dust particles). Diagrams, drawings, graphs, and photographs are provided. 17 refs.

Friedlander, M.W.

1989-01-01

19

FPGA Based Wavelet Trigger in Radio Detection of Cosmic Rays  

NASA Astrophysics Data System (ADS)

Experiments which show coherent radio emission from extensive air showers induced by ultra-high-energy cosmic rays are designed for a detailed study of the development of the electromagnetic part of air showers. Radio detectors can operate with 100 % up time as, e.g., surface detectors based on water-Cherenkov tanks. They are being developed for ground-based experiments (e.g., the Pierre Auger Observatory) as another type of air-shower detector in addition to fluorescence detectors, which operate with only 10 % of duty on dark nights. The radio signals from air showers are caused by coherent emission from geomagnetic radiation and charge-excess processes. The self-triggers in radio detectors currently in use often generate a dense stream of data, which is analyzed afterwards. Huge amounts of registered data require significant manpower for off-line analysis. Improvement of trigger efficiency is a relevant factor. The wavelet trigger, which investigates on-line the power of radio signals ( V2/ R), is promising; however, it requires some improvements with respect to current designs. In this work, Morlet wavelets with various scaling factors were used for an analysis of real data from the Auger Engineering Radio Array and for optimization of the utilization of the resources in an FPGA. The wavelet analysis showed that the power of events is concentrated mostly in a limited range of the frequency spectrum (consistent with a range imposed by the input analog band-pass filter). However, we found several events with suspicious spectral characteristics, where the signal power is spread over the full band-width sampled by a 200 MHz digitizer with significant contribution of very high and very low frequencies. These events may not originate from cosmic ray showers but could be the result of human contamination. The engine of the wavelet analysis can be implemented in the modern powerful FPGAs and can remove suspicious events on-line to reduce the trigger rate.

Szadkowski, Zbigniew; Szadkowska, Anna

2014-12-01

20

FPGA Based Wavelet Trigger in Radio Detection of Cosmic Rays  

NASA Astrophysics Data System (ADS)

Experiments which show coherent radio emission from extensive air showers induced by ultra-high-energy cosmic rays are designed for a detailed study of the development of the electromagnetic part of air showers. Radio detectors can operate with 100 % up time as, e.g., surface detectors based on water-Cherenkov tanks. They are being developed for ground-based experiments (e.g., the Pierre Auger Observatory) as another type of air-shower detector in addition to fluorescence detectors, which operate with only 10 % of duty on dark nights. The radio signals from air showers are caused by coherent emission from geomagnetic radiation and charge-excess processes. The self-triggers in radio detectors currently in use often generate a dense stream of data, which is analyzed afterwards. Huge amounts of registered data require significant manpower for off-line analysis. Improvement of trigger efficiency is a relevant factor. The wavelet trigger, which investigates on-line the power of radio signals (V2/R), is promising; however, it requires some improvements with respect to current designs. In this work, Morlet wavelets with various scaling factors were used for an analysis of real data from the Auger Engineering Radio Array and for optimization of the utilization of the resources in an FPGA. The wavelet analysis showed that the power of events is concentrated mostly in a limited range of the frequency spectrum (consistent with a range imposed by the input analog band-pass filter). However, we found several events with suspicious spectral characteristics, where the signal power is spread over the full band-width sampled by a 200 MHz digitizer with significant contribution of very high and very low frequencies. These events may not originate from cosmic ray showers but could be the result of human contamination. The engine of the wavelet analysis can be implemented in the modern powerful FPGAs and can remove suspicious events on-line to reduce the trigger rate.

Szadkowski, Zbigniew; Szadkowska, Anna

2014-09-01

21

Ultrahigh Energy Cosmic Rays  

E-print Network

This is a review of the most resent results from the investigation of the Ultrahigh Energy Cosmic Rays, particles of energy exceeding 10$^{18}$ eV. After a general introduction to the topic and a brief review of the lower energy cosmic rays and the detection methods, the two most recent experiments, the High Resolution Fly's Eye (HiRes) and the Southern Auger Observatory are described. We then concentrate on the results from these two experiments on the cosmic ray energy spectrum, the chemical composition of these cosmic rays and on the searches for their sources. We conclude with a brief analysis of the controversies in these results and the projects in development and construction that can help solve the remaining problems with these particles.

Letessier-Selvon, Antoine

2011-01-01

22

Ultrahigh energy cosmic rays  

NASA Astrophysics Data System (ADS)

This is a review of the most resent results from the investigation of the ultrahigh energy cosmic rays, particles of energy exceeding 1018eV. After a general introduction to the topic and a brief review of the lower energy cosmic rays and the detection methods, the two most recent experiments, the High Resolution Flys Eye and the Southern Auger Observatory, are described. Results from these two experiments on the cosmic ray energy spectrum, the chemical composition of these cosmic rays, and searches for their sources are presented. An analysis of the controversies in these results and the projects in development and construction that can help solve the remaining problems with these particles is also presented.

Letessier-Selvon, Antoine; Stanev, Todor

2011-07-01

23

Towards the installation and use of an extended array for cosmic ray detection: The EEE Project  

NASA Astrophysics Data System (ADS)

The Extreme Energy Events (EEE) project started to use an array of cosmic ray telescopes for muon detection, distributed over the italian territory. The use of such telescopes, based on Multigap Resistive Plate Chambers (MRPC) allows the study of the local muon flux, the detection of cosmic ray showers and the search for correlations between distant showers. The project is also intended to involve high school teams in an advanced research work. The present status of the installation and the first physics results are discussed here.

Abbrescia, M.; Alici, A.; An, S.; Antolini, R.; Badal, A.; Baek, Y. W.; Baldini Ferroli, R.; Bencivenni, G.; Blanco, F.; Bressan, E.; Chiavassa, A.; Chiri, C.; Cical, C.; Cifarelli, L.; Coccia, E.; Coccetti, F.; de Caro, A.; de Gruttola, D.; de Pasquale, S.; D'Incecco, M.; Fabbri, F. L.; Frolov, V.; Garbini, M.; Guarnaccia, C.; Gustavino, C.; Hatzifotiadou, D.; Imponente, G.; Kim, J. S.; Kim, M. M.; La Rocca, P.; Librizzi, F.; Maggiora, A.; Menghetti, H.; Miozzi, S.; Moro, R.; Noferini, F.; Pagano, P.; Panareo, M.; Pappalardo, G. S.; Petta, C.; Piragino, G.; Preghenella, R.; Riggi, F.; Romano, F.; Russo, G.; Sartorelli, G.; Sbarra, C.; Scioli, G.; Selvi, M.; Serci, S.; Siddi, E.; Wenninger, H.; Williams, M. C. S.; Zampolli, C.; Zichichi, A.; Zuyeuski, R.

2009-05-01

24

Feasibility of cosmic-ray-muon intensity measurements for tunnel detection. Final report, February 1989February 1990  

Microsoft Academic Search

Subsurface cosmic-ray muon intensity depends on the amount of material above the point of reference and is therefore influenced by anomalies in rock density. Because such anomalies might be caused by geological structures (e.g. ore bodies), cosmic-ray intensity measurements have been used for geophysical exploration. Recently, cosmic-ray muon intensity measurements have been also proposed as a method to detect tunnels.

Celmins

1990-01-01

25

29th International Cosmic Ray Conference Pune (2005) 00, 101106 Detection of Diffuse Gamma-Ray Emission from the Cygnus Region  

E-print Network

29th International Cosmic Ray Conference Pune (2005) 00, 101­106 Detection of Diffuse Gamma-Ray of both diffuse and point sources. A large contribution to the VHE emission must come from cosmic rays Emission from the Cygnus Region with the Milagro Gamma-Ray Observatory A.J. Smith for the Milagro

California at Santa Cruz, University of

26

High Energy Cosmic Rays  

E-print Network

T.Hebbeker High Energy Cosmic Rays Thomas Hebbeker RWTH Aachen University Gent 03.07.2008 1.2 http://www.physik.rwth-aachen.de/~hebbeker/ or: google hebbeker #12;T.Hebbeker Cosmic Rays Discovery / Properties Influence on Earth / Life / Science High Energy Cosmic Rays Cosmic Sources and Propagation Auger-Observatory First Auger Results #12;T

Hebbeker, Thomas

27

Detection techniques of radio emission from ultra high energy cosmic rays  

NASA Astrophysics Data System (ADS)

We discuss recent and future efforts to detect radio signals from extended air showers at the Pierre Auger Observatory in Malargue, Argentina. With the advent of low-cost, high-performance digitizers and robust digital signal processing software techniques, radio detection of cosmic rays has resurfaced as a promising measurement system. The inexpensive nature of the detector media (metallic wires, rods or parabolic dishes) and economies of scale working in our favor (inexpensive high-quality C-band amplifiers and receivers) make an array of radio antennas an appealing alternative to the expense of deploying an array of Cherenkov detector water tanks or 'fly's eye' optical telescopes for fluorescence detection. The calorimetric nature of the detection and the near 100% duty cycle gives the best of both traditional detection techniques. The history of cosmic ray detection detection will be discussed. A short review on the astrophysical properties of cosmic rays and atmospheric interactions will lead into a discussion of two radio emission channels that are currently being investigated.

Morris, Chad M.

28

Detection of high energy cosmic rays with the resonant gravitational wave detector NAUTILUS and EXPLORER  

E-print Network

The cryogenic resonant gravitational wave detectors NAUTILUS and EXPLORER, made of an aluminum alloy bar, can detect cosmic ray showers. At temperatures above 1 K, when the material is in the normal conducting state, the measured signals are in good agreement with the values expected based on the cosmic rays data and on the thermo-acoustic model. When NAUTILUS was operated at the temperature of 0.14 K, in superconductive state, large signals produced by cosmic ray interactions, more energetic than expected, were recorded. The NAUTILUS data in this case are in agreement with the measurements done by a dedicated experiment on a particle beam. The biggest recorded event was in EXPLORER and excited the first longitudinal mode to a vibrational energy of about 670 K, corresponding to about 360 TeV absorbed in the bar. Cosmic rays can be an important background in future acoustic detectors of improved sensitivity. At present, they represent a useful tool to verify the gravitational wave antenna performance.

P. Astone; D. Babusci; M. Bassan; P. Bonifazi; G. Cavallari; E. Coccia; S. D'Antonio; V. Fafone; G. Giordano; C. Ligi; A. Marini; G. Mazzitelli; Y. Minenkov; I. Modena; G. Modestino; A. Moleti; G. V. Pallottino; G. Pizzella; L. Quintieri; A. Rocchi; F. Ronga; R. Terenzi; M. Visco

2008-06-14

29

Strangelets in Cosmic Rays  

E-print Network

The properties of strangelets are reviewed and two experiments searching for them in cosmic rays are described. The prospects for strangelets as ultra-high energy cosmic rays beyond the classical GZK-cutoff are discussed.

Jes Madsen

2006-12-29

30

LAT Perspectives in Detection of High Energy Cosmic Ray Electrons  

NASA Technical Reports Server (NTRS)

The GLAST Large Area Telescope (LAT) science objectives and capabilities in the detection of high energy electrons in the energy range from 20 GeV to approx. 1 TeV are presented. LAT simulations are used to establish the event selections. It is found that maintaining the efficiency of electron detection at the level of 30% the residual hadron contamination does not exceed 2-3% of the electron flux. LAT should collect approx. ten million of electrons with the energy above 20 GeV for each year of observation. Precise spectral reconstruction with high statistics presents us with a unique opportunity to investigate several important problems such as studying galactic models of IC radiation, revealing the signatures of nearby sources such as high energy cutoff in the electron spectrum, testing the propagation model, and searching for KKDM particles decay through their contribution to the electron spectrum.

Moiseev, Alexander; Ormes, J. F.; Funk, Stefan

2007-01-01

31

Dual Phase Cosmic Rays  

E-print Network

A calculation based on flat spacetime symmetries shows how there can be two quantum phases. For one, extreme phase change determines a conventional classical trajectory and four-momentum, i.e. mass times four-velocity. The other phase occurs in an effective particle state, with the effective energy and momentum being the rate of change of the phase with respect to time and distance. A cosmic ray proton moves along a classical trajectory, but exists in an effective particle state with an effective energy that depends on the local gravitational potential. Assumptions are made so that a cosmic ray proton in an ultra-high energy state detected near the Earth was in a much less energetic state in interstellar space. A 300 EeV proton incident on the Earth was a 2 PeV proton in interstellar space. The model predicts such protons are in states with even more energy near the Sun than when near the Earth.

Richard Shurtleff

2007-12-30

32

New detection technologies for ultra-high energy cosmic rays and neutrinos  

NASA Astrophysics Data System (ADS)

Even with an accumulated data set from an integrated six years of lifetime from the Auger experiment, no point sources of charged cosmic rays have be identified at the highest energies. Significantly increased apertures such as promised by the JEMEUSO mission will be required to identify these sources from the cosmic ray signatures themselves. However, in employing water-cherenkov surface detectors as well as fluorescence telescopes, Auger has demonstrated the power provided by the hybrid technology approach. New detection technologies thus provide a valuable tool, in particular for the study of systematic effects. Over the past decade, in particular radio detection of cosmic ray air-showers has become a viable future detection technology to enhance and complement existing air-shower experiments. Following the proof-of-principle provided by the Lopes experiment, this technology is now being pursued in all major air-shower detectors. In the MHz regime, the radio signal is dominated by geomagnetic emission from the electrons deflected in the earth magnetic field, with secondary contributions from a global charge excess. As the majority of the energy in the shower is carried by these electron and the radio signal traverses the atmosphere basically unattenuated, this approach not only promises superior energy resolution but may also provide an independent handle on the longitudinal shower development and hence the primary composition. Theoretical signal predictions provided by detailed Monte-Carlo simulations as well as analytic shower parametrizations are in good agreement with measurements provided by the AERA and Codalema experiments. Recent efforts also include studies of the radio emission in the GHz regime, where the ambient noise is significantly reduced, yet the emission mechanism in this regime has not been firmly established yet. As neutrinos are not deflected in the intergalactic magnetic fields, the detection of neutrino-induced cascades in dense media provides another promising approachfor the identification of the sources of cosmic rays. The low event rates and large required target volumes limit the experimental methods to far-ranging signatures .from the cascade, such as acoustic emission from the quasi-instantaneous energy deposit or Cherenkov emission from the charged particles in the cascade. Searching for optical Cherenkov photons in a cubic-kilometer of Antarctic ice, the IceCube experiment has recently found an excess of high-energy neutrinos in the TeV-PeV range.Yet its effective volume is too small to detect the GZK flux predicted from interaction of the highest-energy cosmic rays with the ambient cosmic microwave background. Seeking to increase the observed target volume, radio observations of the rim of the moon have energy thresholds well beyond the EeV scale and thus are more likely to find interactions of charged cosmic rays than GZK neutrinos. The currently best sensitivity to this flux is provided from searches for GHz radio emission of neutrino-induced cascades in the antarctic ice from the ANITA ballon experiment. While no high-energy neutrinos have been found, a geomagnetic emission component from air-showers

Bser, Sebastian

2013-06-01

33

Cosmic Ray Astronomy  

E-print Network

Cosmic ray astronomy attempts to identify and study the sources of ultrahigh energy cosmic rays. It is unique in its reliance on charged particles as the information carriers. While no discrete source of ultrahigh energy cosmic rays has been identified so far, a new generation of detectors is acquiring the huge exposure that is needed at the highest energies, where deflection by magnetic fields is minimized and the background from distant sources is eliminated by pion photoproduction. In this paper, we summarize the status of cosmic ray astronomy, describing the detectors and the analysis techniques.

Paul Sommers; Stefan Westerhoff

2008-02-09

34

Detecting radio emission from cosmic ray air showers and neutrinos with a digital radio telescope  

Microsoft Academic Search

We discuss the possibilities of measuring ultra-high energy cosmic rays and neutrinos with radio techniques. We review a few of the properties of radio emission from cosmic ray air showers and show how these properties can be explained by coherent geosynchrotron emission from electronpositron pairs in the shower as they move through the geomagnetic field. This should allow one to

Heino Falcke; Peter Gorham

2003-01-01

35

Characteristics of plastic CR-39 for detection of relativistic cosmic ray heavy nuclei  

NASA Astrophysics Data System (ADS)

A stack of the plastic CR-39 and nuclear emulsions was exposed at a vertical cut-off rigidity of 10.3 GV and an atmospheric depth of 7 g/cm 2 for 30 h in May, 1979. Characteristics of shapes of etched cones produced by relativistic cosmic ray heavy nuclei in CR-39 are investigated and it is found that the surface ellipse of the etched track with large dip angle becomes more deformed. The detection threshold value is obtained to be Z/ ? ? 6 and the charge resolution (root mean square) to be ?Z ? 0.4 charge units for relativistic iron nuclei in CR-39.

Hayashi, Takayoshi; Doke, Tadayoshi

1980-08-01

36

How Cosmic Rays Affect Humans  

NSDL National Science Digital Library

In this lesson about cosmic rays, students will describe why cosmic rays are dangerous to astronauts. Includes information about student preconceptions. This is activity 3 of 4 from "The Cosmic Ray Telescope for the Effects of Radiation (CRaTER)."

37

Cosmic Rays High Energy Particles  

E-print Network

T.Hebbeker Cosmic Rays High Energy Particles from the Universe Thomas Hebbeker RWTH Aachen.Hebbeker Cosmic Rays Discovery / Properties Influence on Earth / Life / Science High Energy Cosmic Rays Cosmic + + + + + + + + ++ + + + + Ionizing radiation discharges electrometer #12;T.Hebbeker Electric Properties of Cosmic Rays 1927 Clay

Hebbeker, Thomas

38

Origin of Cosmic Rays  

Microsoft Academic Search

Contents Introduction S 1. Primary Cosmic Rays Near the Earth a) Chemical composition b) Energy spectrum S 2. Radio-Astronomical Data a) Magnetic bremsstrahlung (synchrotron radiation) b) Certain results of observations and their interpretation (structure of the Galaxy, discrete sources) S 3. Lifetime of Cosmic Rays and Character of Their Motion in the Galaxy and the Metagalaxy a) Nuclear lifetime of

V. L. Ginzburg; S. I. Syrovatsky

1961-01-01

39

Terrestrial cosmic rays  

Microsoft Academic Search

This paper reviews the basic physics of those cosmic rays which can affect terrestrial electronics. Cosmic rays at sea level consist mostly of neutrons, protons, pions, muons, electrons, and photons. The particles which cause significant soft fails in electronics are those particles with the strong interaction: neutrons, protons, and pions. At sea level, about 95% of these particles are neutrons.

James F. Ziegler

1996-01-01

40

Detection Of Cosmic Rays Air Showers Using Radio Antenna Arrays And Scintillation Counters  

NASA Astrophysics Data System (ADS)

In this progress report we describe a test bench developed in order to evaluate the performance of radio antennas and other gaseous detectors in detecting air showers initiating by cosmic rays. This test bench is based on an array of HELYCON scintillation counters and is used to operate a digital radio telescope. The results of this research and development activity will be applied in developing a sea top calibration array of an underwater neutrino telescope. We also describe the performance of a single HELYCON station in detecting and reconstructing showers as well as on the pilot operation of a single low frequency radio antenna in order to develop techniques to suppress the contribution of the anthropogenic RF background originated from human activities.

Papageorgiou, K.; Tzamarias, S.; Gkialas, I.; Tsirigotis, A.; Bourlis, G.; Manthos, I.; Avgitas, G.

2014-06-01

41

Cosmic Rays High Energy Particles  

E-print Network

T.Hebbeker Cosmic Rays High Energy Particles from the Universe Thomas Hebbeker RWTH Aachen #12;T.Hebbeker Cosmic Rays Discovery / Properties Influence on Earth / Life / Science High Energy Cosmic Rays Cosmic Sources and Propagation Auger-Observatory First Auger Results #12;T.Hebbeker Cosmic

Hebbeker, Thomas

42

DETECTION OF THE COSMIC {gamma}-RAY HORIZON FROM MULTIWAVELENGTH OBSERVATIONS OF BLAZARS  

SciTech Connect

The first statistically significant detection of the cosmic {gamma}-ray horizon (CGRH) that is independent of any extragalactic background light (EBL) model is presented. The CGRH is a fundamental quantity in cosmology. It gives an estimate of the opacity of the universe to very high energy (VHE) {gamma}-ray photons due to photon-photon pair production with the EBL. The only estimations of the CGRH to date are predictions from EBL models and lower limits from {gamma}-ray observations of cosmological blazars and {gamma}-ray bursts. Here, we present homogeneous synchrotron/synchrotron self-Compton (SSC) models of the spectral energy distributions of 15 blazars based on (almost) simultaneous observations from radio up to the highest energy {gamma}-rays taken with the Fermi satellite. These synchrotron/SSC models predict the unattenuated VHE fluxes, which are compared with the observations by imaging atmospheric Cherenkov telescopes. This comparison provides an estimate of the optical depth of the EBL, which allows us a derivation of the CGRH through a maximum likelihood analysis that is EBL-model independent. We find that the observed CGRH is compatible with the current knowledge of the EBL.

Dominguez, A.; Siana, B. [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States); Finke, J. D. [U.S. Naval Research Laboratory, Space Science Division, Code 7653, 4555 Overlook Avenue SW, Washington, DC 20375 (United States); Prada, F. [Campus of International Excellence UAM-CSIC, Cantoblanco, E-28049 Madrid (Spain); Primack, J. R. [Department of Physics, University of California, Santa Cruz, CA 95064 (United States); Kitaura, F. S. [Leibniz-Institut fuer Astrophysik (AIP), An der Sternwarte 16, D-14482 Potsdam (Germany); Paneque, D., E-mail: albertod@ucr.edu [Kavli Institute for Particle Astrophysics and Cosmology, SLAC, Stanford University, Stanford, CA 94305 (United States)

2013-06-10

43

Cosmic Rays at the Knee  

E-print Network

Several kinds of measurements are combined in an attempt to obtain a consistent estimate of the spectrum and composition of the primary cosmic radiation through the knee region. Assuming that the knee is a signal of the high-energy end of a galactic cosmic-ray population, I discuss possible signatures of a transition to an extra-galactic population and how they might be detected.

Thomas K. Gaisser

2006-08-25

44

The origin of galactic cosmic rays  

E-print Network

The origin of galactic cosmic rays is one of the most interesting unsolved problems in astroparticle physics. Experimentally, the problem is attacked by a multi-disciplinary effort, namely by direct measurements of cosmic rays above the atmosphere, by air shower observations, and by the detection of TeV $\\gamma$ rays. Recent experimental results are presented and their implications on the contemporary understanding of the origin of galactic cosmic rays are discussed.

Joerg R. Hoerandel

2007-10-25

45

Detection of the isotopes of heavy cosmic ray nuclei. [by particle counter telescope  

NASA Technical Reports Server (NTRS)

A counter telescope designed to detect and resolve the isotopic composition of cosmic ray nuclei heavier than neon is being prepared. The telescope consists of a rather conventional charge measuring array using two scintillator elements and two solid Cerenkov radiators of differing refractive index. The mass measurement is obtained by combining the velocity information from one or both of the Cerenkov radiators operating near their threshold with residual range measured in a block of nuclear emulsion. Path length corrections and particle location in the emulsions is provided by a spark chamber fired in coincidence with potentially suitable particles. The telescope has a geometry factor of 530 sq cm sr roughly. It should be able to resolve the isotopes of iron over the energy range of 300 to 720 Mev/n and those of neon over 300 to 400 MeV/n. The expected response and characteristics of the telescope are described in detail and the sensitivity to rare isotopes discussed.

Gilman, C. M.; Waddington, C. J.

1975-01-01

46

Cosmic Rays: What Gamma Rays Can Say  

E-print Network

We will review the main channels of gamma ray emission due to the acceleration and propagation of cosmic rays, discussing the cases of both galactic and extra-galactic cosmic rays and their connection with gamma rays observations.

Aloisio, Roberto

2014-01-01

47

Cosmic rays in astrospheres  

E-print Network

Cosmic rays passing through large astrospheres can be efficiently cooled inside these "cavities" in the interstellar medium. Moreover, the energy spectra of these energetic particles are already modulated in front of the astrospherical bow shocks. We study the cosmic ray flux in and around lambda Cephei as an example for an astrosphere. The large-scale plasma flow is modeled hydrodynamically with radiative cooling. We studied the cosmic ray flux in a stellar wind cavity using a transport model based on stochastic differential equations. The required parameters, most importantly, the elements of the diffusion tensor, are based on the heliospheric parameters. The magnetic field required for the diffusion coefficients is calculated kinematically. We discuss the transport in an astrospheric scenario with varying parameters for the transport coefficients. We show that large stellar wind cavities can act as sinks for the galactic cosmic ray flux and thus can give rise to small-scale anisotropies in the direction to...

Scherer, Klaus; Bomans, Dominik; Ferreira, Stefan; Fichtner, Horst; Kleimann, Jens; Strauss, Dutoit; Weis, Kerstin; Wiengarten, Tobias; Wodzinski, Thomas

2015-01-01

48

Cosmic Rays and Climate  

NASA Astrophysics Data System (ADS)

Palaeoclimatic data provide extensive evidence for solar/cosmic ray forcing of Earth's climate on all timescales, but the underlying mechanism remains a mystery. However, satellite data suggest that clouds may be influenced by galactic cosmic rays, which are modulated by the solar wind, by the geomagnetic field and, on longer timescales, by galactic variations. Physical mechanisms to explain the cloud observations have been proposed and modelled. Although these are supported by recent atmospheric observations, definitive mechanistic experiments are lacking. In order to test whether cosmic rays and clouds are causally linked, a novel experiment known as CLOUD has been proposed using a beam from a CERN particle accelerator. This paper presents an overview of the palaeoclimatic evidence for cosmic ray forcing of Earth's climate, and reviews the possible physical mechanisms and the experimental prospects.

Kirkby, J.

2005-12-01

49

Highest Energy Cosmic Rays  

E-print Network

It is proposed that the highest energy $\\sim 10^{20}$eV cosmic ray primaries are protons, decay products of a long-lived progenitor whose high kinetic energy arises from decay of a distant (cosmological) superheavy particle, G. Such a scenario can occur in e.g. SU(15) grand unification and in some preon models, but is more generic; if true, these unusual cosmic rays provide a window into new physics.

Paul H. Frampton

1998-04-22

50

A cocoon of freshly accelerated cosmic rays detected by Fermi in the Cygnus superbubble.  

PubMed

The origin of Galactic cosmic rays is a century-long puzzle. Indirect evidence points to their acceleration by supernova shockwaves, but we know little of their escape from the shock and their evolution through the turbulent medium surrounding massive stars. Gamma rays can probe their spreading through the ambient gas and radiation fields. The Fermi Large Area Telescope (LAT) has observed the star-forming region of Cygnus X. The 1- to 100-gigaelectronvolt images reveal a 50-parsec-wide cocoon of freshly accelerated cosmic rays that flood the cavities carved by the stellar winds and ionization fronts from young stellar clusters. It provides an example to study the youth of cosmic rays in a superbubble environment before they merge into the older Galactic population. PMID:22116880

Ackermann, M; Ajello, M; Allafort, A; Baldini, L; Ballet, J; Barbiellini, G; Bastieri, D; Belfiore, A; Bellazzini, R; Berenji, B; Blandford, R D; Bloom, E D; Bonamente, E; Borgland, A W; Bottacini, E; Brigida, M; Bruel, P; Buehler, R; Buson, S; Caliandro, G A; Cameron, R A; Caraveo, P A; Casandjian, J M; Cecchi, C; Chekhtman, A; Cheung, C C; Chiang, J; Ciprini, S; Claus, R; Cohen-Tanugi, J; de Angelis, A; de Palma, F; Dermer, C D; do Couto E Silva, E; Drell, P S; Dumora, D; Favuzzi, C; Fegan, S J; Focke, W B; Fortin, P; Fukazawa, Y; Fusco, P; Gargano, F; Germani, S; Giglietto, N; Giordano, F; Giroletti, M; Glanzman, T; Godfrey, G; Grenier, I A; Guillemot, L; Guiriec, S; Hadasch, D; Hanabata, Y; Harding, A K; Hayashida, M; Hayashi, K; Hays, E; Jhannesson, G; Johnson, A S; Kamae, T; Katagiri, H; Kataoka, J; Kerr, M; Kndlseder, J; Kuss, M; Lande, J; Latronico, L; Lee, S-H; Longo, F; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Martin, P; Mazziotta, M N; McEnery, J E; Mehault, J; Michelson, P F; Mitthumsiri, W; Mizuno, T; Monte, C; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Naumann-Godo, M; Nolan, P L; Norris, J P; Nuss, E; Ohsugi, T; Okumura, A; Orlando, E; Ormes, J F; Ozaki, M; Paneque, D; Parent, D; Pesce-Rollins, M; Pierbattista, M; Piron, F; Pohl, M; Prokhorov, D; Rain, S; Rando, R; Razzano, M; Reposeur, T; Ritz, S; Parkinson, P M Saz; Sgr, C; Siskind, E J; Smith, P D; Spinelli, P; Strong, A W; Takahashi, H; Tanaka, T; Thayer, J G; Thayer, J B; Thompson, D J; Tibaldo, L; Torres, D F; Tosti, G; Tramacere, A; Troja, E; Uchiyama, Y; Vandenbroucke, J; Vasileiou, V; Vianello, G; Vitale, V; Waite, A P; Wang, P; Winer, B L; Wood, K S; Yang, Z; Zimmer, S; Bontemps, S

2011-11-25

51

Ionisation as indicator for cosmic ray acceleration  

NASA Astrophysics Data System (ADS)

Astrospheres and wind bubbles of massive stars are believed to be sources of cosmic rays with energies E ? 1 TeV. These particles are not directly detectable, but their impact on surrounding matter, in particular ionisation of atomic and molecular hydrogen, can lead to observable signatures. A correlation study of both gamma ray emission, induced by proton-proton interactions of cosmic ray protons with kinetic energies Ep ? 280 MeV with ambient hydrogen, and ionisation induced by cosmic ray protons of kinetic energies Ep < 280 MeV can be performed in order to study potential sources of (sub)TeV cosmic rays.

Schuppan, F.; Rken, C.; Fedrau, N.; Becker Tjus, J.

2014-06-01

52

Cosmic Rays and Climate  

NASA Astrophysics Data System (ADS)

Among the most puzzling questions in climate change is that of solar-climate variability, which has attracted the attention of scientists for more than two centuries. Until recently, even the existence of solar-climate variability has been controversialperhaps because the observations had largely involved correlations between climate and the sunspot cycle that had persisted for only a few decades. Over the last few years, however, diverse reconstructions of past climate change have revealed clear associations with cosmic ray variations recorded in cosmogenic isotope archives, providing persuasive evidence for solar or cosmic ray forcing of the climate. However, despite the increasing evidence of its importance, solar-climate variability is likely to remain controversial until a physical mechanism is established. Although this remains a mystery, observations suggest that cloud cover may be influenced by cosmic rays, which are modulated by the solar wind and, on longer time scales, by the geomagnetic field and by the galactic environment of Earth. Two different classes of microphysical mechanisms have been proposed to connect cosmic rays with clouds: firstly, an influence of cosmic rays on the production of cloud condensation nuclei and, secondly, an influence of cosmic rays on the global electrical circuit in the atmosphere and, in turn, on ice nucleation and other cloud microphysical processes. Considerable progress on understanding ion aerosol cloud processes has been made in recent years, and the results are suggestive of a physically-plausible link between cosmic rays, clouds and climate. However, a concerted effort is now required to carry out definitive laboratory measurements of the fundamental physical and chemical processes involved, and to evaluate their climatic significance with dedicated field observations and modelling studies.

Kirkby, Jasper

2007-11-01

53

Stable quark matter in cosmic rays?  

E-print Network

Stable lumps of quark matter may be present in cosmic rays at a flux level, which can be detected by high precision cosmic ray experiments sensitive to anomalous "nuclei" with high mass-to-charge ratio. The properties of these lumps, called strangelets, are described, and so is the production and propagation of strangelets in cosmic rays. Two experiments underway which are sensitive to a strangelet flux in the predicted range are briefly described. Finally it is summarized how strangelets circumvent the acceleration problem encountered by conventional candidates for ultra-high energy cosmic rays and move the Greisen-Zatsepin-Kuzmin cutoff to energies well above the observed maximum energies.

Jes Madsen

2005-12-20

54

An Optimization of the FPGA Based Wavelet Trigger in Radio Detection of Cosmic Rays  

E-print Network

with 100% up time as e.g. surface detectors based on water- Cherenkov tanks. They are being developed powerful FPGA and can remove suspicious events on-line to reduce the trigger rate. Index Terms-high energy cosmic rays. With its nearly 100% duty cycle, its high angular resolution, and its sensitivity

55

Cosmic ray recipes  

E-print Network

Cosmic rays represent one of the most fascinating research themes in modern astronomy and physics. After almost a century since their discovery, a huge amount of scientific literature has been written on this topic and it is not always easy to extract from it the necessary information for somebody who approaches the subject for the first time. This has been the main motivation for preparing this article, which is a concise and self-contained review for whoever is interested in studying cosmic rays. The priority has been given here to well established facts, which are not at risk to get obsolete in a few years due to the fast progress of the research in this field. Also many data are presented, which are useful to characterize the doses of ionizing radiation delivered to organisms living on the Earth due to cosmic rays. The technical terms which are often encountered in the scientific literature are explained in a separate appendix.

Franco Ferrari; Ewa Szuszkiewicz

2006-01-08

56

Educational Cosmic Ray Arrays  

NASA Astrophysics Data System (ADS)

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

Soluk, R. A.

2006-04-01

57

Detection of High Energy Cosmic Ray with the Advanced Thin Ionization Calorimeter, ATIC  

NASA Astrophysics Data System (ADS)

ATIC is a balloon-borne investigation of cosmic ray spectra, from below 50 GeV to near 100 TeV total energy, using a fully active Bismuth Germanate (BGO) calorimeter. It is equipped with the first large area mosaic of small fully depleted silicon detector pixels capable of charge identification in cosmic rays from H to Fe. As a redundancy check for the charge identification and a coarse particle tracking system, three projective layers of x-y scintillator hodoscopes were employed, above, in the center and below a Carbon interaction `target'. Very high energy ?-rays and their energy spectrum may provide insight to the flux of extremely high energy neutrinos which will be investigated in detail with several proposed cubic kilometer scale neutrino observatories in the next decade.

Fazely, Ali R.

2003-06-01

58

Galactic cosmic rays and nucleosynthesis  

SciTech Connect

The nucleosynthesis of the light elements Li, Be and B by galactic cosmic rays is presented. Observations of cosmic rays and the nuclear reactions responsible for Li, Be and B nucleosynthesis are described, followed by some words on propagation. At the end, some open questions concerning galactic cosmic rays are discussed.

Kiener, Juergen [CSNSM, CNRS-IN2P3 and Universite Paris-Sud, Bat. 104-108, 91405 Orsay Campus (France)

2010-03-01

59

In Search of Cosmic Rays  

NSDL National Science Digital Library

The authors discuss the Cosmic Ray Observatory Project (CROP), focusing on their high school's participation in the project. Students build and monitor cosmic ray detectors to count and study cosmic rays and to determine whether or not the time of day inf

Derek Streich

2001-11-01

60

Cosmic ray research Public lecture  

E-print Network

Cosmic ray research Public lecture Serendipity, colorful scientists and the birth of sub energy cosmic rays in Argentina 2 p.m., Wednesday, October 6, 2010 128 Jabara Hall Watkins Visiting powerful, high-energy cosmic rays that periodically bombard Earth. The project includes more than 450

61

Direct detection of cosmic rays: through a new era of precision measurements of particle fluxes  

NASA Astrophysics Data System (ADS)

In the last years the direct measurement of cosmic rays received a push forward by the possibility of conducting experiments on board long duration balloon flights, satellites and on the International Space Station. The increase in the collected statistics and the technical improvements in the construction of the detectors permit the fluxes measurement to be performed at higher energies with a reduced discrepancy among different experiments respect to the past. However, high statistical precision is not always associated to the needed precision in the estimation of systematics; features in the particle spectra can be erroneously introduced or hidden. A review and a comparison of the latest experimental results on direct cosmic rays measurements will be presented with particular emphasis on their similarities and discrepancies.

Mocchiutti, E.

2014-11-01

62

Interactions of Cosmic Ray Nuclei  

E-print Network

We present convenient formulae for the energy losses of energetic atomic nuclei over the entire energy range relevant to the physics of cosmic rays. Results are applied to a leaky-box equation with a complete loss term. Thereby we derive the equilibrium spectrum of cosmic rays in various types of galaxies. We emphasize a spectral break energy at 450 MeV independent of the matter density, resulting from the transition from Coulomb and ionization losses to pion production losses as the relevant cooling process for the cosmic ray nuclei . We comment on the possible cosmic ray origin of the cosmic gamma ray background.

K. Mannheim; R. Schlickeiser

1994-02-16

63

Ultra High Energy Cosmic Rays  

E-print Network

The origin of the particles in the highest energy end of the cosmic ray spectrum is discussed in the context of the wider problem of the origin of the whole cosmic radiation as observed at the Earth. In particular we focus our attention on the acceleration problem and on the transition from galactic to extragalactic cosmic rays.

Pasquale Blasi

2006-09-29

64

Building a Cloud Chamber (Cosmic Ray Detector)  

NSDL National Science Digital Library

In this activity, students learn about cosmic rays firsthand by building a cloud chamber to detect them. The comprehensive activity includes step-by-step directions for constructing and operating a cloud chamber and ideas for additional experiments.

65

Cosmic Rays: "A Thin Rain of Charged Particles."  

ERIC Educational Resources Information Center

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)

Friedlander, Michael

1990-01-01

66

Origin of cosmic rays  

NASA Astrophysics Data System (ADS)

It is argued that there are three 'origins' of cosmic rays; the origin of the particles, the origin of the energy, and the site of the acceleration. The evidence for each origin is discussed and a plausible synthesis outlined for the particles of Galactic origin where the energy comes mainly (but not exclusively) from supernova explosions, the site of the acceleration is at strong collisionless shock waves, and the accelerated particles come from the interstellar and circumstellar material swept over by these shocks. If these shocks are capable (as indicated by recent observations and theoretical work) of significantly amplifying magnetic fields this picture appears capable of explaining the cosmic ray particles at all energies below the 'ankle' at 3 1018 eV. The particles above this energy are generally taken to be of extra-galactic origin and possible acceleration sites for these UHE particles are briefly discussed.

Drury, Luke O.'C.

2012-12-01

67

Track detector of CR39-DAP-copolymer with variable threshold to detect trans-iron nuclei in galactic cosmic rays  

Microsoft Academic Search

Observation of trans-iron nuclei in galactic cosmic rays (Z?30) requires a high performance cosmic ray detector telescope with a large exposure area because of their extremely low fluxes. A solid-state track detector such as CR-39 has the advantage of easy extension of exposure area, but it is necessary to raise the Z\\/? detection threshold in order to suppress background tracks

S. Kodaira; M. Aasaeda; T. Doke; M. Hareyama; N. Hasebe; K. Ogura; N. Yasuda; T. Tsuruta; Y. Kori

2008-01-01

68

Cosmic Rays above the Knee  

Microsoft Academic Search

An overview on the present observational status and phenomenological understanding of cosmic rays above 10^16 eV is given. Above these energies the cosmic ray flux is expected to be gradually dominated by an extra-galactic component. In order to investigate the nature of this transition, current experimental activities focus on the measurement of the cosmic ray flux and composition at the

Michael Unger

2008-01-01

69

Do cosmic rays drive jets?  

E-print Network

A sudden release of high energy cosmic rays at the centre of a wind sustaining a spiral magnetic field produces cavities of low density and low magnetic field along the axis. The trajectories of high energy cosmic rays are focussed onto the axis, and lower energy cosmic rays and thermal plasma can escape through the cavities. This may explain the jets often seen in accretion systems and elsewhere.

A. R. Bell

2005-07-21

70

Cosmic Necklaces and Ultrahigh Energy Cosmic Rays  

SciTech Connect

Cosmic necklaces are hybrid topological defects consisting of monopoles and strings, with two strings attached to each monopole. We argue that the cosmological evolution of necklaces may significantly differ from that of cosmic strings. The typical velocity of necklaces can be much smaller than the speed of light, and the characteristic scale of the network much smaller than the horizon. We estimate the flux of high-energy protons produced by monopole annihilation in the decaying closed loops. For some reasonable values of the parameters it is comparable to the observed flux of ultrahigh-energy cosmic rays. {copyright} {ital 1997} {ital The American Physical Society}

Berezinsky, V. [INFN, Laboratori Nazionali del Gran Sasso, 67010 Assergi (Antarctica) (Italy)] [INFN, Laboratori Nazionali del Gran Sasso, 67010 Assergi (Antarctica) (Italy); Vilenkin, A. [Institute of Cosmology, Department of Physics and Astronomy, Tufts University, Medford, Massachusetts 02155 (United States)] [Institute of Cosmology, Department of Physics and Astronomy, Tufts University, Medford, Massachusetts 02155 (United States)

1997-12-01

71

Cosmic Rays and Climate Change  

NASA Astrophysics Data System (ADS)

A survey is made of the evidence for and against the hypothesis that cosmic rays affect cloud cover and thereby surface temperature. The analysis is made for the troposphere in the main and it includes correlations of cloud cover with cosmic ray intensity, Forbush decreases, cosmic ray short period increases and eleven year changes; also included are the electrical effects associated with cosmic rays. A complementary study comprises a search for extra cloud cover associated with terrestrial radon emissions, the Chernobyl accident and nuclear bomb tests. It is concluded that the best estimate of the fraction of (low) cloud cover attributable to a 2% change in cosmic ray intensity is about 0.02%. Insofar as the maximum change in average cosmic ray intensity over the last 50 years is about 0.2%, no more than 0.01% of cloud cover change in this period can have been caused by cosmic rays; their contribution to Global Warming is thus considered to be negligible. Not surprisingly, we find that the effect of cosmic rays on stratospheric cloud is bigger, by a factor of at least ten. In both the troposphere and the stratosphere the cosmic ray effects at the Poles are bigger than average.

Erlykin, A. D.; Laken, B. A.; Sloan, T.; Wolfendale, A. W.

2010-09-01

72

Detecting Low-Contrast Features in the Cosmic Ray Albedo Proton Yield Map of the Moon  

NASA Astrophysics Data System (ADS)

High energy cosmic rays constantly bombard the lunar regolith, producing (via nuclear evaporation[1]) secondary 'albedo' or 'splash' particles like protons and neutrons, some of which escape back to space. Lunar Prospector and the Lunar Reconnaissance Orbiter (LRO), have shown that the energy distribution of albedo neutrons is modulated by the elemental composition of the lunar regolith[2-5], and by ice deposits[6] in permanently shadowed polar craters. Here we investigate an analogous phenomenon with high energy lunar albedo protons. Using the CRaTER instrument (Cosmic Ray Telescope for the Effects of Radiation) on LRO, we measure albedo protons (60 to 150 MeV) to construct a cosmic ray albedo proton map of the Moon. Our current map is a significant improvement over the proof-of-concept map of Wilson et al.[7]. In addition to using more numerous minimum ionizing GCR protons for normalization, we filter out all solar particle enhancement periods and make use of all six of CRaTER's detectors to reduce contamination from spurious non-proton events in the data stream. The average yield of albedo protons from the maria is 0.8% 0.4% higher than the yield from the highlands. In addition there appear to be localized peaks in the albedo proton yield that are co-located with peaks in trace elemental abundances as measured by the Lunar Prospector Gamma Ray Spectrometer. More data may reveal subtler proton yield variations correlated with latitude, time of day, or the locations of permanently shadowed craters, due to the presence of water frost. Given that the most obvious features in the map have a proton yield only 2? above average, the search for more subtle regions of enhancement or reduction in proton yield will require precise corrections for small but systematic effects of time and spacecraft altitude on the apparent proton yield. We will show the effects of these trends as well as the latest version of the albedo proton map. References: [1] Bethe (1937) Rev. Mod. Phys., 9, 69. [2] Feldman W. C. et al. (1998) Science, 281, 1496-1500. [3] Gasnault, O. et al. (2001) GRL, 28, 3797-3800. [4] Maurice, S. et al. (2004) JGR, 109, E07S04. [5] Mitrofanov I. G. et al. (2010) Science, 330, 483-486. [6] Feldman W. C. et al. (1997) JGR, 102, 25565-25574. [7] Wilson, J. K. et al. (2012) JGR, 117, E00H23. Figure 1. Top: Color-coded lunar albedo proton map, with two high-yielding mare regions labeled 'A' and 'B'. Bottom: Clementine white-light mosaic of lunar surface.

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

2013-12-01

73

Cosmic Ray Energetics And Mass  

NASA Astrophysics Data System (ADS)

The balloon-borne Cosmic Ray Energetics And Mass (CREAM) experiment was flown for ~161 days in six flights over Antarctica. High energy cosmic-ray data were collected over a wide energy range from ~ 10^10 to > 10^14 eV at an average altitude of ~38.5 km with ~3.9 g/cm2 atmospheric overburden. Cosmic-ray elements from protons (Z = 1) to iron nuclei (Z = 26) are separated with excellent charge resolution. Building on success of the balloon flights, the payload is being reconfigured for exposure on the International Space Station (ISS). This ISS-CREAM instrument is configured with the CREAM calorimeter for energy measurements, and four finely segmented Silicon Charge Detector layers for precise charge measurements. In addition, the Top and Bottom Counting Detectors (TCD and BCD) and Boronated Scintillator Detector (BSD) have been newly developed. The TCD and BCD are scintillator based segmented detectors to separate electrons from nuclei using the shower profile differences, while BSD distinguishes electrons from nuclei by detecting thermal neutrons that are dominant in nuclei induced showers. An order of magnitude increase in data collecting power is possible by utilizing the ISS to reach the highest energies practical with direct measurements. The project status including results from on-going analysis of existing data and future plans will be discussed.

Seo, Eun-Suk

2014-08-01

74

Antiprotons in cosmic rays  

NASA Technical Reports Server (NTRS)

Recent experimental observations and results are discussed. It was found that the approximately 50 antiprotons collected in balloon experiments to date have generated considerable theoretical interest. Clearly, confirmatory experiments and measurements over an extended energy range are required before definite conclusions are drawn. Antiproton measurements have a bearing on astrophysical problems ranging from cosmic ray propagation to issues of cosmological import. The next generation of balloon experiments and the Particle Astrophysics Magnet Facility being discussed for operation on NASA's space station should provide data and insights of highest interest.

Balasubrahmanyan, V. K.; Ormes, J. F.; Streitmatter, R. E.

1987-01-01

75

The Origin of Cosmic Rays  

SciTech Connect

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 end 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 cosmic ray astronomy, 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.

Pasquale Blasi

2008-02-20

76

The Origin of Cosmic Rays  

ScienceCinema

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 ?end? 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 ?cosmic ray astronomy?, 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.

Pasquale Blasi

2010-01-08

77

Cosmic Rays from Cosmic Strings with Condensates  

E-print Network

We re-visit the production of cosmic rays by cusps on cosmic strings. If a scalar field (``Higgs'') has a linear interaction with the string world-sheet, such as would occur if there is a bosonic condensate on the string, cusps on string loops emit narrow beams of very high energy Higgses which then decay to give a flux of ultra high energy cosmic rays. The ultra-high energy flux and the gamma to proton ratio agree with observations if the string scale is $\\sim 10^{13}$ GeV. The diffuse gamma ray and proton fluxes are well below current bounds. Strings that are {\\it lighter} and have linear interactions with scalars produce an excess of direct and diffuse cosmic rays and are ruled out by observations, while heavier strings ($\\sim 10^{15}$ GeV) are constrained by their gravitational signatures. This leaves a narrow window of parameter space for the existence of cosmic strings with bosonic condensates.

Tanmay Vachaspati

2009-11-13

78

Fast calibration methods using cosmic rays for a neutron detection array  

NASA Astrophysics Data System (ADS)

An overall irradiation and calibration technique was introduced and applied to a test scintillation detector array. An integral conversion method was used to reduce the nonlinearity of the time difference spectrum, and to improve the position determination especially for positions close to the two ends of a long scintillation bar. An overall position resolution of about 3.0 cm (FWHM) was extracted from the residual analysis method and verified by a direct measurement. Energy calibration was also realized by selecting cosmic rays at different incident angles. The bulk light attenuation lengths for the four test bars were also determined. It is demonstrated that these methods are especially efficient for calibrating large and complex detector arrays.

Yang, Zai-Hong; Ye, Yan-Lin; Xiao, Jun; You, Hai-Bo; Liu, Hong-Na; Sun, Ye-Lei; Wang, Zi-Heng; Chen, Jie

2012-03-01

79

Cosmic Ray Positrons from Cosmic Strings  

E-print Network

We study the spectrum of cosmic ray positrons produced by a scaling distribution of non-superconducting cosmic strings. In this scenario, the positrons are produced from the jets which form from the cosmic string cusp annihilation process. The spectral shape is a robust feature of our scenario, and is in good agreement with the results from the recent PAMELA and ATIC experiments. In particular, the model predicts a sharp upper cutoff in the spectrum, and a flux which rises as the upper cutoff is approached. The energy at which the flux peaks is determined by the initial jet energy. The amplitude of the flux can be adjusted by changing the cosmic string tension and also depends on the cusp annihilation efficiency.

Brandenberger, Robert; Xue, Wei; Zhang, Xinmin

2009-01-01

80

Cosmic Ray Positrons from Cosmic Strings  

E-print Network

We study the spectrum of cosmic ray positrons produced by a scaling distribution of non-superconducting cosmic strings. In this scenario, the positrons are produced from the jets which form from the cosmic string cusp annihilation process. The spectral shape is a robust feature of our scenario, and is in good agreement with the results from the recent PAMELA and ATIC experiments. In particular, the model predicts a sharp upper cutoff in the spectrum, and a flux which rises as the upper cutoff is approached. The energy at which the flux peaks is determined by the initial jet energy. The amplitude of the flux can be adjusted by changing the cosmic string tension and also depends on the cusp annihilation efficiency.

Robert Brandenberger; Yi-Fu Cai; Wei Xue; Xinmin Zhang

2009-01-22

81

Testing Galactic Cosmic Ray Models  

NASA Technical Reports Server (NTRS)

Models of the Galactic Cosmic Ray Environment are used for designing and planning space missions. The exising models will be reviewed. Spectral representations from these models will be compared with measurements of galactic cosmic ray spectra made on balloon flights and satellite flights over a period of more than 50 years.

Adams, James H., Jr.

2010-01-01

82

Cosmic Rays, Clouds, and Climate  

Microsoft Academic Search

It has been proposed that Earth's climate could be affected by changes in cloudiness caused by variations in the intensity of galactic cosmic rays in the atmosphere. This proposal stems from an observed correlation between cosmic ray intensity and Earth's average cloud cover over the course of one solar cycle. Some scientists question the reliability of the observations, whereas others,

K. S. Carslaw; R. G. Harrison; J. Kirkby

2002-01-01

83

Testing Galactic Cosmic Ray Models  

NASA Technical Reports Server (NTRS)

Models of the Galactic Cosmic Ray Environment are used for designing and planning space missions. The existing models will be reviewed. Spectral representations from these models will be compared with measurements of galactic cosmic ray spectra made on balloon flights and satellite flights over a period of more than 50 years.

Adams, James H., Jr.

2009-01-01

84

24. Cosmic rays 1 24. COSMIC RAYS  

E-print Network

on gyroradius or magnetic rigidity, R, which is gyroradius multiplied by the magnetic field strength: R = p c Z particles are "modulated" by the solar wind, the expanding magnetized plasma generated by the Sun, which per unit rigidity. Propagation (and probably also acceleration) through cosmic magnetic fields depends

85

26. Cosmic rays 1 26. COSMIC RAYS  

E-print Network

on gyroradius or magnetic rigidity, R, which is gyroradius multiplied by the magnetic field strength: R = p c Z particles are "modulated" by the solar wind, the expanding magnetized plasma generated by the Sun, which per unit rigidity. Propagation (and probably also acceleration) through cosmic magnetic fields depends

86

Physics of solar cosmic rays  

NASA Technical Reports Server (NTRS)

A review of the historical development of solar cosmic ray research is presented and details concerning the solar atmosphere, the interplanetary space, and solar activity are considered, giving attention to solar-atmosphere structure, problems of radiative transfer, questions of solar magnetism, solar wind, and interplanetary plasmas. Solar flares and associated phenomena are discussed along with the generation of solar cosmic ray events, the mechanism of solar flares, the acceleration process of solar cosmic rays, the propagation of solar cosmic rays, and relations between the flow of energetic protons and solar active regions. Questions regarding the origin theory of cosmic rays are also explored, taking into account the solar origin theory and problems of flare stars.

Sakurai, K.

1974-01-01

87

COSMIC-RAY TRANSPORT AND ANISOTROPIES  

SciTech Connect

We show that the large-scale cosmic-ray anisotropy at {approx}10 TeV can be explained by a modified Compton-Getting effect in the magnetized flow field of old supernova remnants. Cosmic rays arrive isotropically to the flow field and are then carried along with the flow to produce a large-scale anisotropy in the arrival direction. This approach suggests an optimum energy scale for detecting the anisotropy. Two key assumptions are that propagation is based on turbulence following a Kolmogorov law and that cosmic-ray interactions are dominated by transport via cosmic-ray-excited magnetic irregularities through the stellar wind of an exploding star and its shock shell. A prediction is that the amplitude is smaller at lower energies due to incomplete sampling of the velocity field and also smaller at larger energies due to smearing.

Biermann, Peter L. [MPI for Radioastronomy, Auf dem Huegel 69, D-53121 Bonn (Germany); Becker Tjus, Julia; Mandelartz, Matthias [Ruhr-Universitaet Bochum, Fakultaet fuer Physik and Astronomie, Theoretische Physik I, D-44780 Bochum (Germany); Seo, Eun-Suk [Department of Physics, University of Maryland, College Park, MD 20742 (United States)

2013-05-10

88

A Bayesian self-clustering analysis of the highest energy cosmic rays detected by the Pierre Auger Observatory  

E-print Network

Cosmic rays (CRs) are protons and atomic nuclei that flow into our Solar system and reach the Earth with energies of up to ~10^21 eV. The sources of ultra-high energy cosmic rays (UHECRs) with E >~ 10^19 eV remain unknown, although there are theoretical reasons to think that at least some come from active galactic nuclei (AGNs). One way to assess the different hypotheses is by analysing the arrival directions of UHECRs, in particular their self-clustering. We have developed a fully Bayesian approach to analyzing the self-clustering of points on the sphere, which we apply to the UHECR arrival directions. The analysis is based on a multi-step approach that enables the application of Bayesian model comparison to cases with weak prior information. We have applied this approach to the 69 highest energy events recorded by the Pierre Auger Observatory (PAO), which is the largest current UHECR data set. We do not detect self-clustering, but simulations show that this is consistent with the AGN-sourced model for a dat...

Khanin, Alexander

2014-01-01

89

Cosmic rays are on the air Studying the properties of radio signals from cosmic-ray  

E-print Network

Cosmic rays are on the air Studying the properties of radio signals from cosmic-ray induced air showers #12;#12;Cosmic rays are on the air Studying the properties of radio signals from cosmic-ray;#12;Contents 1 Introduction 1 1.1 Discovery of cosmic rays . . . . . . . . . . . . . . . . . . . . . . . 1 1

van Suijlekom, Walter

90

Galactic Cosmic Rays: From Earth to Sources  

NASA Technical Reports Server (NTRS)

For nearly 100 years we have known that cosmic rays come from outer space, yet proof of their origin, as well as a comprehensive understanding of their acceleration, remains elusive. Direct detection of high energy (up to 10(exp 15)eV), charged nuclei with experiments such as the balloon-born, antarctic Trans-Iron Galactic Element Recorder (TIGER) have provided insight into these mysteries through measurements of cosmic ray abundances. The abundance of these rare elements with respect to certain intrinsic properties suggests that cosmic rays include a component of massive star ejecta. Supernovae and their remnants (SNe & SNRs), often occurring at the end of a massive star's life or in an environment including massive star material, are one of the most likely candidates for sources accelerating galactic comic ray nuclei up to the requisite high energies. The Fermi Gamma-ray Space Telescope Large Area Detector (Fermi LAT) has improved our understanding of such sources by widening the window of observable energies and thus into potential sources' energetic processes. In combination with multiwavelength observations, we are now better able to constrain particle populations (often hadron-dominated at GeV energies) and environmental conditions, such as the magnetic field strength. The SNR CTB 37A is one such source which could contribute to the observed galactic cosmic rays. By assembling populations of SNRs, we will be able to more definitively define their contribution to the observed galactic cosmic rays, as well as better understand SNRs themselves. Such multimessenger studies will thus illuminate the long-standing cosmic ray mysteries, shedding light on potential sources, acceleration mechanisms, and cosmic ray propagation.

Brandt, Theresa J.

2012-01-01

91

Cosmic Rays and Global Warming  

E-print Network

It has been claimed by others that observed temporal correlations of terrestrial cloud cover with `the cosmic ray intensity' are causal. The possibility arises, therefore, of a connection between cosmic rays and Global Warming. If true, the implications would be very great. We have examined this claim to look for evidence to corroborate it. So far we have not found any and so our tentative conclusions are to doubt it. Such correlations as appear are more likely to be due to the small variations in solar irradiance, which, of course, correlate with cosmic rays. We estimate that less than 15% of the 11-year cycle warming variations are due to cosmic rays and less than 2% of the warming over the last 35 years is due to this cause.

T. Sloan; A W Wolfendale

2007-06-28

92

Antennas for the Detection of Radio Emission Pulses from Cosmic-Ray induced Air Showers at the Pierre Auger Observatory  

E-print Network

The Pierre Auger Observatory is exploring the potential of the radio detection technique to study extensive air showers induced by ultra-high energy cosmic rays. The Auger Engineering Radio Array (AERA) addresses both technological and scientific aspects of the radio technique. A first phase of AERA has been operating since September 2010 with detector stations observing radio signals at frequencies between 30 and 80 MHz. In this paper we present comparative studies to identify and optimize the antenna design for the final configuration of AERA consisting of 160 individual radio detector stations. The transient nature of the air shower signal requires a detailed description of the antenna sensor. As the ultra-wideband reception of pulses is not widely discussed in antenna literature, we review the relevant antenna characteristics and enhance theoretical considerations towards the impulse response of antennas including polarization effects and multiple signal reflections. On the basis of the vector effective l...

Abreu, P; Ahlers, M; Ahn, E J; Albuquerque, I F M; Allard, D; Allekotte, I; Allen, J; Allison, P; Almela, A; Castillo, J Alvarez; Alvarez-Muiz, J; Batista, R Alves; Ambrosio, M; Aminaei, A; Anchordoqui, L; Andringa, S; Anti?i?, 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; Buml, J; Baus, C; Beatty, J J; Becker, K H; Belltoile, A; Bellido, J A; BenZvi, S; Berat, C; Bertou, X; Biermann, P L; Billoir, P; Blanco, F; Blanco, M; Bleve, C; Blmer, H; Boh\\'{?ov, 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; Diaz, J Chirinos; Chudoba, J; Cilmo, M; Clay, R W; Cocciolo, G; Collica, L; Coluccia, M R; Conceio, 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; Junior, W J M de Mello; Neto, J R T de Mello; De Mitri, I; de Souza, V; de Vries, K D; del Peral, L; del Ro, M; Deligny, O; Dembinski, H; Dhital, N; Di Giulio, C; Castro, M L Daz; Diep, P N; Diogo, F; Dobrigkeit, C; Docters, W; D'Olivo, J C; Dong, P N; Dorofeev, A; Anjos, J C dos; Dova, M T; D'Urso, D; Dutan, I; Ebr, J; Engel, R; Erdmann, M; Escobar, C O; Espadanal, J; Etchegoyen, A; Luis, P Facal San; Falcke, H; Farrar, G; Fauth, A C; Fazzini, N; Ferguson, A P; Fick, B; Figueira, J M; Filevich, A; Filip?i?, A; Fliescher, S; Fracchiolla, C E; Fraenkel, E D; Fratu, O; Frhlich, U; Fuchs, B; Gaior, R; Gamarra, R F; Gambetta, S; Garca, B; Roca, S T Garcia; Garcia-Gamez, D; Garcia-Pinto, D; Bravo, A Gascon; Gemmeke, H; Ghia, P L; Giller, M; Gitto, J; Glass, H; Gold, M S; Golup, G; Albarracin, F Gomez; Berisso, M Gmez; Vitale, P F Gmez; Gonalves, P; Gonzalez, J G; Gookin, B; Gorgi, A; Gouffon, P; Grashorn, E; Grebe, S; Griffith, N; Grigat, M; 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; Hojvat, C; Hollon, N; Holmes, V C; Homola, P; Hrandel, J R; Horvath, P; Hrabovsk, 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; Kgl, 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; Krmer, O; Kruppke-Hansen, D; Kuempel, D; Kulbartz, J K; Kunka, N; La Rosa, G; Lachaud, C; LaHurd, D; Latronico, L; Lauer, R; Lautridou, P; Coz, S Le; Leo, M S A B; Lebrun, D; Lebrun, P; de Oliveira, M A Leigui; Letessier-Selvon, A; Lhenry-Yvon, I; Link, K; Lpez, R; Agera, A Lopez; Louedec, K; Bahilo, J Lozano; 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; Falcon, H R Marquez; Marsella, G; Martello, D; Martin, L; Martinez, H; Bravo, O Martnez; Martraire, D; Meza, J J Masas; 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; Meurer, C; Meyhandan, R; Mi?anovi?, S; Micheletti, M I; Minaya, I A; Miramonti, L; Molina-Bueno, L; Mollerach, S; Monasor, M; Ragaigne, D Monnier; Montanet, F; Morales, B; Morello, C; Moreno, E; Moreno, J C; Mostaf, M; Moura, C A; Muller, M A; Mller, G; Mnchmeyer, 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; Noka, L; Oehlschlger, J; Olinto, A; Ortiz, M; Pacheco, N; Selmi-Dei, D Pakk; Palatka, M; Pallotta, J; Palmieri, N; Parente, G; Parizot, E; Parra, A; Pastor, S; Paul, T; Pech, M; P?kala, 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; de Carvalho, W Rodrigues; Rodriguez, G; Cabo, I Rodriguez; Martino, J Rodriguez; Rojo, J Rodriguez; Rodrguez-Fras, M D; Ros, G; Rosado, J

2012-01-01

93

Models for cosmic ray interactions  

E-print Network

Contemporary models of hadronic interactions are reviewed. Basic phenomenological approaches are compared, with an emphasizes on the predicted air shower characteristics. Special attention is payed to the remaining discrepancies between present hadronic MC generators and cosmic ray data. Finally, future prospects concerning model improvements are discussed, in particular, regarding the possibilities to discriminate between different models on the basis of accelerator or cosmic ray measurements.

S. Ostapchenko

2006-01-27

94

Cosmic ray driven outflows  

E-print Network

We present simulations of the magnetized interstellar medium (ISM) in models of massive star forming (40 Msun / yr) disk galaxies with high gas surface densities (~100 Msun / pc^2) similar to observed star forming high-redshift disks. We assume that type II supernovae deposit 10 per cent of their energy into the ISM as cosmic rays and neglect the additional deposition of thermal energy or momentum. With a typical Galactic diffusion coefficient for CRs (3e28 cm^2 / s) we demonstrate that this process alone can trigger the local formation of a strong low density galactic wind maintaining vertically open field lines. Driven by the additional pressure gradient of the relativistic fluid the wind speed can exceed 1000 km/s, much higher than the escape velocity of the galaxy. The global mass loading, i.e. the ratio of the gas mass leaving the galactic disk in a wind to the star formation rate becomes of order unity once the system has settled into an equilibrium. We conclude that relativistic particles accelerated i...

Hanasz, Michal; Naab, Thorsten; Gawryszczak, Artur; Kowalik, Kacper; Wlta?ski, Dominik

2013-01-01

95

Gamma Ray Astronomy and the Origin of Galactic Cosmic Rays  

E-print Network

Diffusive shock acceleration operating at expanding supernova remnant shells is by far the most popular model for the origin of galactic cosmic rays. Despite the general consensus received by this model, an unambiguous and conclusive proof of the supernova remnant hypothesis is still missing. In this context, the recent developments in gamma ray astronomy provide us with precious insights into the problem of the origin of galactic cosmic rays, since production of gamma rays is expected both during the acceleration of cosmic rays at supernova remnant shocks and during their subsequent propagation in the interstellar medium. In particular, the recent detection of a number of supernova remnants at TeV energies nicely fits with the model, but it still does not constitute a conclusive proof of it, mainly due to the difficulty of disentangling the hadronic and leptonic contributions to the observed gamma ray emission. In this paper, the most relevant cosmic-ray-related results of gamma ray astronomy are briefly summarized, and the foreseeable contribution of future gamma ray observations to the final solution of the problem of cosmic ray origin is discussed.

Stefano Gabici

2008-11-05

96

High energy cosmic rays, gamma rays and neutrinos from AGN  

E-print Network

The author reviews a model for the emission of high energy cosmic rays, gamma-rays and neutrinos from AGN (Active Galactic Nuclei) that he has proposed since 1985. Further discussion of the knee energy phenomenon of the cosmic ray energy spectrum requires the existence of a heavy particle with mass in the knee energy range. A possible method of detecting such a particle in the Pierre Auger Project is suggested. Also presented is a relation between the spectra of neutrinos and gamma-rays emitted from AGN. This relation can be tested by high energy neutrino detectors such as ICECUBE, the Mediterranean Sea Detector and possibly by the Pierre Auger Project.

Yukio Tomozawa

2008-02-03

97

Cosmic-Ray Observations with HAWC30  

NASA Astrophysics Data System (ADS)

The High-Altitude Water Cherenkov (HAWC) Observatory is a TeV gamma-ray and cosmic-ray detector currently under construction at an altitude of 4100 meters on the slope of Volc'an Sierra Negra near Puebla, Mexico. HAWC is an extensive air-shower array comprising 300 optically-isolated water Cherenkov detectors. Each detector contains 200,000 liters of filtered water and four upward-facing photomultiplier tubes. Since September 2012, 30 water Cherenkov detectors have been instrumented and operated in data acquisition. With 10 percent of the detector complete and six months of operation, the event statistics are already sufficient to perform detailed studies of cosmic rays observed at the site. We will report on cosmic-ray observations with HAWC30, in particular the detection and study of the shadow of the moon. From these observations, we infer the pointing accuracy of the detector and our angular resolution of the detector reconstruction.

Fiorino, Daniel

2013-04-01

98

Investigation of primary cosmic rays at the Moon's surface  

SciTech Connect

The possibility of experimentally studying primary cosmic rays at the Moon's surface is considered. A mathematical simulations of showers initiated in the lunar regolith by high-energy particles of primary cosmic rays is performed. It is shown that such particles can in principle be recorded by simultaneously detecting three components of backscattered radiation (secondary neutrons, gamma rays, and radio emission).

Kalmykov, N. N., E-mail: kalm@eas.sinp.msu.ru; Konstantinov, A. A. [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation)] [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation); Muhamedshin, R. A. [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation)] [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation); Podorozhniy, D. M.; Sveshnikova, L. G.; Turundaevskiy, A. N. [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation)] [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation); Tkachev, L. G. [Joint Institute for Nuclear Research (Russian Federation)] [Joint Institute for Nuclear Research (Russian Federation); Chubenko, A. P. [Russian Academy of Sciences, Lebedev Institute of Physics (Russian Federation)] [Russian Academy of Sciences, Lebedev Institute of Physics (Russian Federation); Vasilyev, O. A. [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation)] [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation)

2013-01-15

99

Irradiated ISM: Discriminating between Cosmic Rays and X-rays  

E-print Network

The ISM of active galaxy centers is exposed to a combination of cosmic ray, FUV and X-ray radiation. We apply PDR models to this ISM with both `normal' and highly elevated (5\\times 10^{-15}s^-1) cosmic-ray rates and compare the results to those obtained for XDRs. Our existing PDR-XDR code is used to construct models over a 10^3-10^5 cm^-3 density range and for 0.16-160 erg s^-1 cm^-2 impingent fluxes. We obtain larger high J (J>10) CO ratios in PDRs when we use the highly elevated cosmic ray rate, but these are always exceeded by the corresponding XDR ratios. The [CI] 609 mum/13CO(2-1) line ratio is boosted by a factor of a few in PDRs with n~10^3 cm^-3 exposed to a high cosmic ray rate. At higher densities ratios become identical irrespective of cosmic ray flux, while XDRs always show elevated [CI] emission per CO column. The HCN/CO and HCN/HCO+ line ratios, combined with high J CO emission lines, are good diagnostics to distinguish between PDRs under either low or high cosmic ray irradiation conditions, and XDRs. Hence, the HIFI instrument on Herschel, which can detect these CO lines, will be crucial in the study of active galaxies.

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

2006-09-07

100

LARGE-SCALE DISTRIBUTION OF ARRIVAL DIRECTIONS OF COSMIC RAYS DETECTED ABOVE 10{sup 18} eV AT THE PIERRE AUGER OBSERVATORY  

SciTech Connect

A thorough search for large-scale anisotropies in the distribution of arrival directions of cosmic rays detected above 10{sup 18} 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 10{sup 18} 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 10{sup 18} eV from stationary Galactic sources densely distributed in the Galactic disk and predominantly emitting light particles in all directions.

Abreu, P.; Andringa, S. [LIP and Instituto Superior Tecnico, Technical University of Lisbon (Portugal); Aglietta, M. [Istituto di Fisica dello Spazio Interplanetario (INAF), Universita di Torino and Sezione INFN, Torino (Italy); Ahlers, M. [University of Wisconsin, Madison, WI (United States); Ahn, E. J. [Fermilab, Batavia, IL (United States); Albuquerque, I. F. M. [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo, SP (Brazil); Allard, D. [Laboratoire AstroParticule et Cosmologie (APC), Universite Paris 7, CNRS-IN2P3, Paris (France); Allekotte, I. [Centro Atomico Bariloche and Instituto Balseiro (CNEA-UNCuyo-CONICET), San Carlos de Bariloche (Argentina); Allen, J. [New York University, New York, NY (United States); Allison, P. [Ohio State University, Columbus, OH (United States); Almela, A. [Facultad Regional Buenos Aires, Universidad Tecnologica Nacional, Buenos Aires (Argentina); Alvarez Castillo, J. [Universidad Nacional Autonoma de Mexico, Mexico, D. F. (Mexico); Alvarez-Muniz, J. [Universidad de Santiago de Compostela (Spain); Alves Batista, R. [IFGW, Universidade Estadual de Campinas, Campinas, SP (Brazil); Ambrosio, M.; Aramo, C. [Universita di Napoli 'Federico II' and Sezione INFN, Napoli (Italy); Aminaei, A. [IMAPP, Radboud University Nijmegen (Netherlands); Anchordoqui, L. [University of Wisconsin, Milwaukee, WI (United States); Antici'c, T. [Rudjer Boskovi'c Institute, 10000 Zagreb (Croatia); Arganda, E. [IFLP, Universidad Nacional de La Plata and CONICET, La Plata (Argentina); Collaboration: Pierre Auger Collaboration; and others

2012-12-15

101

Compact cosmic ray detector for unattended atmospheric ionization monitoring  

SciTech Connect

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.

Aplin, K. L. [Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Harrison, R. G. [Meteorology Department, University of Reading, PO Box 243, Earley Gate, Reading RG6 6BB (United Kingdom)

2010-12-15

102

Catching Cosmic Rays with a DSLR  

ERIC Educational Resources Information Center

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

Sibbernsen, Kendra

2010-01-01

103

Monopole Annihilation and Highest Energy Cosmic Rays  

E-print Network

Cosmic rays with energies exceeding $10^{20}\\eV$ have been detected. The origin of these highest energy cosmic rays remains unknown. Established astrophysical acceleration mechanisms encounter severe difficulties in accelerating particles to these energies. Alternative scenarios where these particles are created by the decay of cosmic topological defects have been suggested in literature. In this paper we study the possibility of producing the highest energy cosmic rays through a process that involves formation of metastable magnetic monopole-antimonopole bound states and their subsequent collapse. The annihilation of the heavy monopole-antimonopole pairs constituting the monopolonia can produce energetic nucleons, gamma rays and neutrinos whose expected flux we estimate and discuss in relation to experimental data so far available. The monopoles we consider are the ones that could be produced in the early universe during a phase transition at the grand unification energy scale. We find that observable cosmic ray fluxes can be produced with monopole abundances compatible with present bounds.

P. Bhattacharjee; G. Sigl

1994-12-15

104

Cosmic Ray Muons in QCD  

NASA Astrophysics Data System (ADS)

Despite 100 years of effort, many aspects of cosmic rays are still not well understood. Studies of high-energy muons produced in cosmic ray air showers are an important part of this effort. These muons are produced by the decays of pions and kaons at lower energies, and by charm quarks above about 1 TeV. Measurement of these muons can be used to determine the composition of cosmic rays. Moreover, the muons are produced at far-forward rapidities and are an excellent complement to data collected by accelerators at lower rapidity. Underground detectors have studied cosmic ray muons and measured lateral separations ranging from the meter scale to hundreds of meters. For larger separations, the muon transverse momentum is in excess of 6 GeV/c and muon interactions can be characterized using perturbative QCD. These measurements can be used to extend accelerator measurements to higher center of mass energies and rapidities, and have important implications for charm production as well as cosmic ray composition.

Gerhardt, Lisa

2012-03-01

105

The ?-ray and cosmic ray connection: Ulysses HET secondary radioisotope measurements and cosmic ray propagation  

NASA Astrophysics Data System (ADS)

Cosmic rays constitute a super-thermal gas of charged particles magnetically confined within the Galaxy. Cosmic ray nuclei and electrons are a principal source of the diffuse ?-ray background in the Galaxy. Thus, understanding diffuse ?-ray production is directly related to understanding cosmic ray propagation in the Galaxy. While propagating though the interstellar medium (ISM), cosmic ray nuclei undergo nuclear spallation reactions, producing both stable and unstable secondary nuclei. Measurements of secondary radioisotopes are crucial tests of cosmic ray propagation. The abundances of some radioactive secondary isotopes (10Be, 26Al, 36Cl, etc.) measure the average density of material cosmic rays traverse and relate to the confinement times of cosmic rays in the Galaxy. The abundances of electron capture isotopes and their daughter nuclei (for example, 49V and 51V) test the role of cosmic ray reacceleration. The Ulysses High Energy Telescope (HET) is a cosmic ray isotope spectrometer with sufficient mass resolution (~0.28 u at Fe) and collecting area to measure these rare isotopes. The latest HET measurements of the radioactive secondary cosmic ray isotopes are given, and the implications for cosmic ray propagation and diffuse ?-ray production are discussed. .

Connell, J. J.; Simpson, J. A.

2000-04-01

106

A focussing iron line crystal spectrometer for Spacelab. [cosmic X-ray detection  

NASA Technical Reports Server (NTRS)

A crystal spectrometer system is described which employs conical focusing of 12 curved LiF crystal panels to minimize the detector size and reduce the background counting rate. The wavelength range from 1.70 to 1.98 A is covered, including the resonance lines of Fe XXV and Fe XXVI as well as the Fe I K-alpha line and absorption edge. Operation of the spectrometer is discussed, noting that diffracted X-rays are registered in one-dimensional position-sensitive detectors and that the arrival position of a photon in a detector is related to its wavelength due to the fixed curvature of the crystal panels in the dispersion plane. Some characteristics of the multianode position-sensitive detectors are reviewed along with the crystal arrangement and mounting. The instrument sensitivity is evaluated in relation to the strengths of 6.7-keV emission features detected by the Ariel 5 and OSO 8 proportional-counter spectrometers.

Catura, R. C.; Culhane, J. L.; Rapley, C. G.; Gabriel, A. H.; Walker, A. B. C., Jr.; Woodgate, B. E.

1977-01-01

107

Cosmic Rays and Sunspot Numbers  

NSDL National Science Digital Library

In this activity students analyze and compare two or more graphs to determine if there is a correlation between sunspot number and the variation of cosmic ray flux. They discover that cosmic rays are very energetic particles, mostly protons and electrons, that enter the solar system from the depths of interstellar space and that although the Earth's magnetic field partially shields us from these particles, so too does the much more extended solar wind with its own magnetic field. This is a three-part lesson in which students will construct line graphs displaying the cosmic ray flux and sunspot numbers for a period of time, and then determine if there is a correlation. In order to compare these two sets of data, students will need to scale the data in order to visualize the results. Teacher and student notes for the graphing calculator are included.

Higley, Susan

108

Cosmic Rays and Global Warming  

SciTech Connect

Some workers have claimed that the observed temporal correlations of (low level) terrestrial cloud cover with the cosmic ray intensity changes, due to solar modulation, are causal. The possibility arises, therefore, of a connection between cosmic rays and Global Warming. If true, the implications would be very great. We have examined this claim in some detail. So far, we have not found any evidence in support and so our conclusions are to doubt it. From the absence of corroborative evidence we estimate that less than 15% at the 95% confidence level, of the 11-year cycle warming variations are due to cosmic rays and less than 2% of the warming over the last 43 years is due to this cause. The origin of the correlation itself is probably the cycle of solar irradiance although there is, as yet, no certainty.

Sloan, T. [Physics Department, University of Lancaster, Lancaster, UK (United Kingdom); Wolfendale, A. W. [Physics Department, Durham University, Durham (United Kingdom)

2008-01-24

109

Cosmic Rays above the Knee  

E-print Network

An overview on the present observational status and phenomenological understanding of cosmic rays above 10^16 eV is given. Above these energies the cosmic ray flux is expected to be gradually dominated by an extra-galactic component. In order to investigate the nature of this transition, current experimental activities focus on the measurement of the cosmic ray flux and composition at the 'ankle' or 'dip' feature at several EeV. At the ultra high energy end of the spectrum, the flux suppression above 50 EeV is now well established by the measurements of HiRes and the Pierre Auger Observatory and we may enter the era of charged particle astronomy.

Michael Unger

2008-12-15

110

The microphysics and macrophysics of cosmic rays  

SciTech Connect

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 cosmic rays can be generated by the cosmic rays themselves through a microinstability excited by their streaming. A quasilinear treatment of the cosmic raywave 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.

Zweibel, Ellen G. [Departments of Astronomy and Physics and Center for Magnetic Self-Organization, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)] [Departments of Astronomy and Physics and Center for Magnetic Self-Organization, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

2013-05-15

111

The Lateral Trigger Probability function for the UltraHigh Energy Cosmic Ray showers detected by the Pierre Auger Observatory  

Microsoft Academic Search

In this paper we introduce the concept of Lateral Trigger Probability (LTP) function, i.e., the probability for an Extensive Air Shower (EAS) to trigger an individual detector of a ground based array as a function of distance to the shower axis, taking into account energy, mass and direction of the primary cosmic ray. We apply this concept to the surface

P. Abreu; M. Aglietta; E. J. Ahn; I. F. M. Albuquerque; D. Allard; I. Allekotte; J. Allen; P. Allison; J. Alvarez Castillo; M. Ambrosio; A. Aminaei; L. Anchordoqui; S. Andringa; T. Anti?i?; A. Anzalone; C. Aramo; E. Arganda; F. Arqueros; H. Asorey; P. Assis; J. Aublin; M. Avenier; G. Avila; T. Bcker; M. Balzer; K. B. Barber; A. F. Barbosa; R. Bardenet; S. L. C. Barroso; B. Baughman; J. Buml; J. J. Beatty; B. R. Becker; K. H. Becker; A. Belltoile; J. A. Bellido; S. BenZvi; C. Berat; X. Bertou; P. L. Biermann; P. Billoir; F. Blanco; M. Blanco; H. Blmer; M. Boh?ov; D. Boncioli; C. Bonifazi; R. Bonino; N. Borodai; J. Brack; P. Brogueira; W. C. Brown; R. Bruijn; P. Buchholz; A. Bueno; R. E. Burton; K. S. Caballero-Mora; L. Caramete; R. Caruso; A. Castellina; O. Catalano; G. Cataldi; L. Cazon; R. Cester; J. Chauvin; S. H. Cheng; A. Chiavassa; J. A. Chinellato; J. Chudoba; R. W. Clay; M. R. Coluccia; F. Contreras; H. Cook; M. J. Cooper; A. Cordier; U. Cotti; S. Coutu; C. E. Covault; A. Creusot; J. Cronin; A. Curutiu; S. Dagoret-Campagne; R. Dallier; S. Dasso; K. Daumiller; B. R. Dawson; R. M. de Almeida; C. De Donato; S. J. de Jong; G. De La Vega; I. De Mitri; V. de Souza; K. D. de Vries; G. Decerprit; L. del Peral; O. Deligny; H. Dembinski; N. Dhital; C. Di Giulio; J. C. Diaz; M. L. D?az Castro; P. N. Diep; C. Dobrigkeit; W. Docters; J. C. DOlivo; P. N. Dong; A. Dorofeev; J. C. dos Anjos; M. T. Dova; D. DUrso; I. Dutan; J. Ebr; R. Engel; M. Erdmann; C. O. Escobar; A. Etchegoyen; P. Facal San Luis; I. Fajardo Tapia; H. Falcke; G. Farrar; A. C. Fauth; N. Fazzini; A. P. Ferguson; A. Ferrero; B. Fick; A. Filevich; S. Fliescher; C. E. Fracchiolla; U. Frhlich; B. Fuchs; R. Gaior; R. F. Gamarra; S. Gambetta; B. Garc?a; D. Garc?a Gmez; D. Garca Gmez; A. Gascon; H. Gemmeke; K. Gesterling; P. L. Ghia; U. Giaccari; M. Giller; H. Glass; M. S. Gold; G. Golup; F. Gomez Albarracin; M. Gmez Berisso; P. Gonalves; D. Gonzalez; J. G. Gonzalez; B. Gookin; D. Gra; A. Gorgi; P. Gouffon; S. R. Gozzini; E. Grashorn; S. Grebe; N. Griffith; M. Grigat; A. F. Grillo; Y. Guardincerri; F. Guarino; G. P. Guedes; A. Guzman; J. D. Hague; P. Hansen; D. Harari; S. Harmsma; J. L. Harton; A. Haungs; T. Hebbeker; D. Heck; A. E. Herve; C. Hojvat; N. Hollon; V. C. Holmes; P. Homola; J. R. Hrandel; A. Horneffer; M. Hrabovsk; T. Huege; A. Insolia; F. Ionita; A. Italiano; C. Jarne; S. Jiraskova; K. Kadija; K. H. Kampert; P. Karhan; B. Kgl; B. Keilhauer; A. Keivani; J. L. Kelley; E. Kemp; R. M. Kieckhafer; H. O. Klages; M. Kleifges; J. Kleinfeller; D.-H. Koang; K. Kotera; N. Krohm; O. Krmer; D. Kruppke-Hansen; F. Kuehn; D. Kuempel; J. K. Kulbartz; N. Kunka; G. La Rosa; C. Lachaud; P. Lautridou; M. S. A. B. Leo; D. Lebrun; P. Lebrun; M. A. Leigui de Oliveira; A. Letessier-Selvon; I. Lhenry-Yvon; K. Link; R. Lpez; A. Lopez Agera; K. Louedec; J. Lozano Bahilo; A. Lucero; M. Ludwig; H. Lyberis; M. C. Maccarone; S. Maldera; D. Mandat; P. Mantsch; A. G. Mariazzi; J. Marin; V. Marin; I. C. Maris; H. R. Marquez Falcon; G. Marsella; D. Martello; L. Martin; H. Martinez; O. Mart?nez Bravo; H. J. Mathes; J. A. J. Matthews; G. Matthiae; D. Maurizio; P. O. Mazur; G. Medina-Tanco; M. Melissas; D. Melo; E. Menichetti; A. Menshikov; P. Mertsch; C. Meurer; S. Mi?anovi?; M. I. Micheletti; W. Miller; L. Miramonti; S. Mollerach; M. Monasor; D. Monnier Ragaigne; F. Montanet; B. Morales; C. Morello; E. Moreno; J. C. Moreno; M. Mostaf; C. A. Moura; S. Mueller; M. A. Muller; G. Mller; M. Mnchmeyer; R. Mussa; G. Navarra; J. L. Navarro; S. Navas; P. Necesal; L. Nellen; A. Nelles; P. T. Nhung; L. Niemietz; N. Nierstenhoefer; D. Nitz; D. Nosek; L. Noka; M. Nyklicek; J. Oehlschlger; A. Olinto; P. Oliva; V. M. Olmos-Gilbaja; N. Pacheco; D. Pakk Selmi-Dei; M. Palatka; J. Pallotta; N. Palmieri; G. Parente; E. Parizot; A. Parra; R. D. Parsons; S. Pastor; T. Paul; M. Pech; R. Pelayo; I. M. Pepe; L. Perrone; R. Pesce; E. Petermann; S. Petrera; P. Petrinca; A. Petrolini; Y. Petrov; J. Petrovic; C. Pfendner; N. Phan; R. Piegaia; T. Pierog; P. Pieroni; M. Pimenta; V. Pirronello; M. Platino; V. H. Ponce; M. Pontz; P. Privitera; M. Prouza; E. J. Quel; S. Querchfeld; J. Rautenberg; O. Ravel; D. Ravignani; B. Revenu; J. Ridky; S. Riggi; M. Risse; P. Ristori; H. Rivera; V. Rizi; J. Roberts; C. Robledo; W. Rodrigues de Carvalho; G. Rodriguez; J. Rodriguez Martino; I. Rodriguez-Cabo; M. D. Rodr?guez-Fr?as; G. Ros; J. Rosado; T. Rossler; M. Roth; B. Rouill-dOrfeuil; E. Roulet; A. C. Rovero; F. Salamida; H. Salazar; G. Salina; F. Snchez; M. Santander; C. E. Santo; E. M. Santos; F. Sarazin; B. Sarkar; S. Sarkar; R. Sato; N. Scharf; V. Scherini; H. Schieler; P. Schiffer; A. Schmidt; F. Schmidt; T. Schmidt; O. Scholten; H. Schoorlemmer; J. Schovancova

2011-01-01

112

High-Energy X-Ray Detection of G359.89-0.08 (SGR A-E): Magnetic Flux Tube Emission Powered by Cosmic Rays?  

NASA Technical Reports Server (NTRS)

We report the first detection of high-energy X-ray (E (is) greater than 10 keV) emission from the Galactic center non-thermal filament G359.89-0.08 (Sgr A-E) using data acquired with the Nuclear Spectroscopic Telescope Array (NuSTAR). The bright filament was detected up to approximately 50 keV during a NuSTAR Galactic center monitoring campaign. The featureless power-law spectrum with a photon index gamma approximately equals 2.3 confirms a non-thermal emission mechanism. The observed flux in the 3-79 keV band is F(sub X) = (2.0 +/- 0.1) 10(exp -12)erg cm(-2) s(-1) , corresponding to an unabsorbed X-ray luminosity L(sub X) = (2.6+/-0.8)10(exp 34) erg s(-1) assuming a distance of 8.0 kpc. Based on theoretical predictions and observations, we conclude that Sgr A-E is unlikely to be a pulsar wind nebula (PWN) or supernova remnant-molecular cloud (SNR-MC) interaction, as previously hypothesized. Instead, the emission could be due to a magnetic flux tube which traps TeV electrons. We propose two possible TeV electron sources: old PWNe (up to (is) approximately 100 kyr) with low surface brightness and radii up to (is) approximately 30 pc or MCs illuminated by cosmic rays (CRs) from CR accelerators such as SNRs or Sgr A*.

Zhang, Shuo; Hailey, Charles J.; Baganoff, Frederick K.; Bauer, Franz E.; Boggs, Steven E.; Craig, William W.; Christensen, Finn E.; Gotthelf, Eric V.; Harrison, Fiona A.; Mori, Kaya; Nynka, Melania; Stern, Daniel; Tomsick, John A; Zhang, Will

2014-01-01

113

Cosmic Rays and Space Situational Awareness in Europe  

Microsoft Academic Search

In this paper European space weather activities are sketched and the contribution of cosmic ray research and technology to the European space situational awareness programme is described. Especially the cosmic ray muon detection technique is studied - on ground and in future space based -, because it is considered to be very useful for coronal mass ejection forecast in the

F. Jansen; J. Behrens

114

Muon Charge Ratio of Ultrahigh Energy Cosmic Rays  

E-print Network

The muon charge ratio of ultrahigh energy cosmic rays may provide information to detect the composition of the primary cosmic rays. We propose to extract the charge information of high energy muons in very inclined extensive air showers by analyzing their relative lateral positions in the shower transverse plane.

Bo-Qiang Ma

2008-08-19

115

Evaluation of Galactic Cosmic Ray Models  

NASA Technical Reports Server (NTRS)

Models of the galactic cosmic ray spectra have been tested by comparing their predictions to an evaluated database containing more than 380 measured cosmic ray spectra extending from 1960 to the present.

Adams, James H., Jr.; Heiblim, Samuel; Malott, Christopher

2009-01-01

116

30TH INTERNATIONAL COSMIC RAY CONFERENCE Numerical Model of Cosmic Ray Induced Ionization in the Atmosphere  

E-print Network

30TH INTERNATIONAL COSMIC RAY CONFERENCE Numerical Model of Cosmic Ray Induced Ionization.usoskin@oulu.fi Abstract: We present a full numerical model to calculate cosmic ray induced ionization in the at- mosphere practical applications are discussed. Introduction Energetic galactic cosmic rays (CR) form an im- portant

Usoskin, Ilya G.

117

28th International Cosmic Ray Conference 3905 Galactic Cosmic Ray Fluctuations: Long-term Modulation  

E-print Network

28th International Cosmic Ray Conference 3905 Galactic Cosmic Ray Fluctuations: Long study the time evolution of power spectra of galac- tic cosmic ray fluctuations during the last three monitors, Tixie Bay (Russia) and Oulu (Finland). We have shown that the power spectrum of cosmic ray

Usoskin, Ilya G.

118

28th International Cosmic Ray Conference 3473 REal-time COsmic Ray Database (RECORD)  

E-print Network

28th International Cosmic Ray Conference 3473 REal-time COsmic Ray Database (RECORD) Valery Kozlov, Moscow region, Russia. Abstract In this paper we present a first distributed REal-time COsmic Ray methods. The database contains not only original cosmic ray data but also auxiliary data necessary

Usoskin, Ilya G.

119

Frontiers of Cosmic Ray Science 205 Long-Term Variations of Cosmic Rays and Terrestrial  

E-print Network

Frontiers of Cosmic Ray Science 205 Long-Term Variations of Cosmic Rays and Terrestrial Environmentth International Cosmic Ray Conference (August 2003, Tsukuba, Japan): SH 3.4 "Long-term variations," SH 3.5 "Long-term variation of cosmic rays studied by cosmogenic nuclides," SH 3.6 "Terrestrial

Usoskin, Ilya G.

120

29th International Cosmic Ray Conference Pune (2005) 00, 101104 A Cherenkov imager for charge measurements of Nuclear Cosmic Rays  

E-print Network

29th International Cosmic Ray Conference Pune (2005) 00, 101­104 A Cherenkov imager for charge Cherenkov imager for the charge measurement of nuclear cosmic rays in the CREAM II instrument, called gap. The Cherenkov light yield is proportional to the squared charge of the detected particle

Paris-Sud XI, Université de

121

28th International Cosmic Ray Conference 4065 The Cosmic Ray Shadows of the Moon and the Sun De-  

E-print Network

28th International Cosmic Ray Conference 4065 The Cosmic Ray Shadows of the Moon and the Sun De of the data shows that the shadows of the sun and moon have each been detected with high significances of the sun is significantly weaker than that of the moon. As expected, the measured positions of the deficits

California at Santa Cruz, University of

122

Lunar/Solar effects on Cosmic Rays  

E-print Network

Lunar/Solar effects on Cosmic Rays By: Sophia Bauer & Jenna Valdez #12;Introduction When cosmic rays travel through the moon they will decay because of the mass of the moon. Therefore there should be less cosmic rays coming into the earth's atmosphere from the direction of the moon. We were interested

California at Santa Cruz, University of

123

Imaging the High Energy Cosmic Ray Sky  

E-print Network

Imaging the High Energy Cosmic Ray Sky PETTER HOFVERBERG Licentiate Thesis Stockholm, Sweden 2006 #12;#12;Licentiate Thesis Imaging the High Energy Cosmic Ray Sky Petter Hofverberg Particle Stockholm, Sweden 2006 #12;Cover illustration: The sky coverage of cosmic rays for the SEASA array

Haviland, David

124

How Cosmic Rays Affect Learning Objectives  

E-print Network

1 CRaTER: How Cosmic Rays Affect Humans Learning Objectives: · Students will be able to describe why cosmic rays are dangerous to astronauts. · Studentswilllearntodesignascientificinstrument. · Students will think critically about how to protect astronauts from cosmic rays. Preparation: None

Christian, Eric

125

PAMELA measurements of high energy cosmic ray  

E-print Network

PAMELA measurements of high energy cosmic ray positrons LAURA ROSSETTO Doctoral Thesis Stockholm, Sweden 2012 #12;#12;Doctoral Thesis PAMELA measurements of high energy cosmic ray positrons Laura from the calorimeter, positrons can be identified from the significant background due to cosmic ray

Haviland, David

126

Galactic cosmic rays M.-B. Kallenrode  

E-print Network

Galactic cosmic rays M.-B. Kallenrode University of L¨uneburg, 21332 L¨uneburg, Germany Camera.: ??? First author: Kallenrode 1 Galactic cosmic rays M.-B. Kallenrode University of L¨uneburg, 21332 L¨uneburg, Germany This presentation gives a brief review of galactic cosmic rays. It starts with observations made

Steinhoff, Heinz-Jürgen

127

LATERAL DISTRIBUTION OF COSMIC RAY MUONS UNDERGROUND  

E-print Network

LATERAL DISTRIBUTION OF COSMIC RAY MUONS UNDERGROUND: Results from the CosmoALEPH Experiment?at Siegen Siegen 2006 #12; LATERAL DISTRIBUTION OF COSMIC RAY MUONS UNDERGROUND: Results from the Cosmo; ABSTRACT LATERAL DISTRIBUTION OF COSMIC RAY MUONS UNDERGROUND: Results from the CosmoALEPH Experiment

Siegen, Universität

128

Cosmic rays and hadronic interactions  

SciTech Connect

The cosmic ray spectrum extends to particles with energy E{approx} 10{sup 20} eV, that corresponds (assuming that the primary particle is a proton) to a nucleon-nucleon c.m. energy {radical}(s) Asymptotically-Equal-To 430TeV, 50 times higher than the current LHC energy. These very high energy particles can be studied via the observation of the showers they generate in the atmosphere. The interpretation of the data requires therefore the modeling of hadronic interactions in an energy range beyond what can be studied in accelerator experiments. The theoretical problem of estimating the relevant properties of hadronic interactions in this energy range is therefore of central importance for the interpretation of the cosmic ray data. Viceversa, it is in principle possible to obtain information about hadronic interactions from the cosmic ray observations, but this program has to confront the fact that the (freely available) cosmic ray beam has an unknown energy spectrum and an unknown mass composition.

Lipari, Paolo [INFN sez. Roma, and Dipartimento di Fisica, Universita di Roma Sapienza (Italy)

2013-03-25

129

The Cosmic Ray Electron Excess  

NASA Technical Reports Server (NTRS)

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.

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.; Panasyuk, M. I.; Panov, A. D.; Schmidt, W. K. H.; Seo, E. S.; Sokolskaya, N. V.; Watts, J. W.; Wefel, J. P.; Wu, J.; Zatsepin, V. I.

2008-01-01

130

First results from the microwave air yield beam experiment (MAYBE): Measurement of GHz radiation for ultra-high energy cosmic ray detection  

NASA Astrophysics Data System (ADS)

We present measurements of microwave emission from an electron-beam induced air plasma performed at the 3 MeV electron Van de Graaff facility of the Argonne National Laboratory. Results include the emission spectrum between 1 and 15 GHz, the polarization of the microwave radiation and the scaling of the emitted power with respect to beam intensity. MAYBE measurements provide further insight on microwave emission from extensive air showers as a novel detection technique for Ultra-High Energy Cosmic Rays.

Williams, C.; Boh?ov, M.; Bonifazi, C.; Cataldi, G.; Chemerisov, S.; de Mello Neto, J. R. T.; Facal San Luis, P.; Fox, B.; Gorham, P. W.; Hojvat, C.; Hollon, N.; Meyhandan, R.; Monasor, M.; Rouill d'Orfeuil, B.; Santos, E. M.; Pochez, J.; Privitera, P.; Spinka, H.; Verzi, V.; Zhou, J.

2013-06-01

131

Signatures of cosmic-ray interactions on the solar surface  

NASA Technical Reports Server (NTRS)

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

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

1991-01-01

132

Cosmic Gamma-ray Background Radiation  

E-print Network

The cosmic gamma-ray background radiation is one of the most fundamental observables in the gamma-ray band. Although the origin of the cosmic gamma-ray background radiation has been a mystery for a long time, the Fermi gamma-ray space telescope has recently measured it at 0.1-820 GeV and revealed that the cosmic GeV gamma-ray background is composed of blazars, radio galaxies, and star-forming galaxies. However, Fermi still leaves the following questions. Those are dark matter contribution, origins of the cosmic MeV gamma-ray background, and the connection to the IceCube TeV-PeV neutrino events. In this proceeding, I will review the current understandings of the cosmic gamma-ray background and discuss future prospects of cosmic gamma-ray background radiation studies. I also briefly review the current status of cosmic infrared/optical background radiation studies.

Inoue, Yoshiyuki

2014-01-01

133

High-energy Cosmic Rays  

E-print Network

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

Thomas K. Gaisser; Todor Stanev

2005-10-11

134

Cosmic Ray DetectorC. Little1,2, M. Barnett1, D. Chabot1, R. Igarashi1, T. Mavrichi1, R. Pywell1, W. Wurtz1 Cosmic Ray DetectorCosmic Ray DetectorC. Little1,2, M. Barnett1, D. Chabot1, R. Igarashi1, T. Mavrichi1, R. Pywell1, W. Wurtz1  

E-print Network

Cosmic Ray DetectorC. Little1,2, M. Barnett1, D. Chabot1, R. Igarashi1, T. Mavrichi1, R. Pywell1, W. Wurtz1 Cosmic Ray DetectorCosmic Ray DetectorC. Little1,2, M. Barnett1, D. Chabot1, R. Igarashi1, T. Mavrichi1, R. Pywell1, W. Wurtz1 Method of DetectionMethod of DetectionCosmic RaysCosmic Rays Why Detect

Saskatchewan, University of

135

Search for AntiparticleSearch for Antiparticle in Cosmic Raysin Cosmic Rays  

E-print Network

Search for AntiparticleSearch for Antiparticle in Cosmic Raysin Cosmic Rays with BESSwith BESS ·University of Denver J. Ormes, N. Thakur #12;CosmicCosmic--Ray Antiproton ChronologyRay Antiproton ChronologySearch for Primordial Antiparticles in CosmicAntiparticles in Cosmic RaysRays Primary origins relatively enhanced at

Yamamoto, Hirosuke

136

Cosmic x ray physics  

NASA Technical Reports Server (NTRS)

This final report covers the period 1 January 1985 - 31 March 1992. It is divided into the following sections: the soft x-ray background; proportional counter and filter calibrations; sounding rocket flight preparations; new sounding rocket payload: x-ray calorimeter; and theoretical studies. Staff, publications, conference proceedings, invited talks, contributed talks, colloquia and seminars, public service lectures, and Ph. D. theses are listed.

Mccammon, Dan; Cox, D. P.; Kraushaar, W. L.; Sanders, W. T.

1992-01-01

137

30TH INTERNATIONAL COSMIC RAY CONFERENCE A Search for Prompt Very High Energy Emission from Satellite-detected Gamma-  

E-print Network

Satellite-detected Gamma- ray Bursts using Milagro P. M. SAZ PARKINSON & B. L. DINGUS ¡ FOR THE MILAGRO@scipp.ucsc.edu; dingus@lanl.gov Abstract: Gamma-ray bursts (GRBs) have been detected up to GeV energies and are predicted

California at Santa Cruz, University of

138

Neutrons and antiprotons in ultrahigh energy cosmic rays  

E-print Network

The neutron fraction in the very high energy cosmic rays near the Greisen-Zatsepin-Kuzmin (GZK) cutoff energy is analyzed by taking into account the time dilation effect of the neutron decays and also the pion photoproduction behaviors above the GZK cutoff. We predict a non-trivial neutron fraction above the GZK cutoff and a negligibly small neutron fraction below. However, there should be a large antiproton fraction in the high energy cosmic rays below the GZK cutoff in several existing models for the observed cosmic-ray events above and near the GZK cutoff. Such a large antiproton fraction can manifest itself by the muon charge ratio $\\mu^+/\\mu^-$ in the collisions of the primary nucleon cosmic rays with the atmosphere, if there is no neutron contribution. We suggest to use the muon charge ratio as one of the information to detect the composition of the primary cosmic rays near or below the GZK cutoff.

W-Y. P. Hwang; Bo-Qiang Ma

2005-09-06

139

Distributed reacceleration of cosmic rays  

NASA Technical Reports Server (NTRS)

We develop a model in which cosmic rays, in addition to their initial acceleration by a strong shock, are continuously reaccelerated (e.g., by weak shocks) while propagating through the galaxy. The equations describing this acceleration scheme are solved analytically (approximating ionization losses by a cutoff) and numerically. Solutions for the spectra of primary and secondary cosmic rays are given in a closed analytic form, and they allow a rapid search in parameter space for viable propagation models with distributed reacceleration included. The observed boron-to-carbon ratio can be reproduced by the reacceleration theory over a range of escape parameters, some of them quite different from the standard "leaky box" model. It is also shown that even a very modest amount of reacceleration by strong shocks causes the boron-to carbon ratio to level off at sufficiently high energies, and this effect may be observed in the CRNE data. Several other curiosities in the data may be explained naturally if a modest amount of distributed reacceleration is invoked, including (a) the apparent truncation at low energy in the otherwise exponential pathlength distribution associated with the leaky box model, (b) the sub-iron isotopic anomalies and other effects noted by Silberberg et al., and (c) the discrepancy between the reported 10Be lifetime and the lifetime of cosmic rays in the dense strata of the galactic disk.

Wandel, A.; Eichler, D.; Letaw, J. R.; Silberberg, R.; Tsao, C. H.

1987-01-01

140

Cosmic ray acceleration search in Supernova Remnants  

NASA Astrophysics Data System (ADS)

Galactic Supernova Remnants (SNRs) are among the best candidates as source of cosmic rays due to energetics, observed rate of explosion and as possible sites where the Fermi mechanisms naturally plays a key role. Evidence of hadronic acceleration processes taking place in SNRs are being collected with the Fermi-LAT, whose sensitivity in the range 100MeV-100GeV is crucial for disentangling possible hadronic contribution from inverse Compton or bremsstrahlung leptonic component. A survey of the detected SNRs will be given, focusing the attention on the role of the environment and the evolution stage of the SNR in the interpretation of the observed ?-ray spectra.

Giordano, Francesco; Di Venere, Leonardo

2014-11-01

141

High energy solar cosmic rays detection by the Baksan air shower arrays, Andyrchy and Carpet , during 23rd solar cycle  

NASA Astrophysics Data System (ADS)

Total counting rate of two scintillation Baksan air shower arrays "Andyrchy" and "Carpet" was examined during Ground Level Enhancements (GLEs) observed in the 23rd cycle of solar activity. Significant excesses above the galactic cosmic ray background have been found during several GLE events. The magnitude of increases at the peak of intensity-time profiles during different GLEs amounts to 4-14 st.dev. (0.12-0.44% excess) by the 15-min data of "Andyrchy". The "Carpet" array has two times higher statistical accuracy than "Andyrchy" under the same observation conditions. The data of both Baksan shower arrays are compared with the neutron monitors data at Apatity and Moscow. The total counting rate of both arrays consists mainly of single detector events(one-fold). The counting rate of two-fold, three-fold and greater events are few percents of total one. One-fold component is produced by secondary single muons and by small local air showers (electrons and gamma rays). The energy of primary hadrons caused one- fold component is higher than that for neutron monitors and amounts a few tens of GeV. The data of two air shower arrays, "Andyrchy" and "Carpet", open a new interesting possibility to study solar cosmic rays in the energy range of few tens of GeV.

Alekseenko, V.; Karpov, S.; Karpova, Z.; Khaerdinov, N.; Petkov, V.; Poddubny, V.; Zaichenko, A.

142

Cloud chamber visualization of primary cosmic rays  

SciTech Connect

From 1948 until 1963, cloud chambers were carried to the top of the atmosphere by balloons. From these flights, which were begun by Edward P. Ney at the University of Minnesota, came the following results: discovery of heavy cosmic ray nuclei, development of scintillation and cherenkov detectors, discovery of cosmic ray electrons, and studies of solar proton events. The history of that era is illustrated here by cloud chamber photographs of primary cosmic rays.

Earl, James A. [Department of Astronomy, University of Maryland, College Park MD (United States)

2013-02-07

143

Cosmic ray nuclei from extragalactic and galactic pulsars  

NASA Astrophysics Data System (ADS)

In an extragalactic newly-born pulsar, nuclei striped off the star surface can be accelerated to extreme energies and leave the source through dense supernova surroundings. The escaped ultrahigh energy cosmic rays can explain both UHE energy spectral and atmospheric depth observations. In addition, assuming that Galactic pulsars accelerate cosmic rays with the same injection composition, very high energy cosmic rays from local pulsars can meet the flux measurements from above the knee to the ankle, and at the same time, agree with the detected composition trend.

Fang, Ke

2013-02-01

144

Observation of a rare cosmic ray event at mountain altitude  

NASA Astrophysics Data System (ADS)

Existence of strangelets in cosmic rays has been predicted even at mountain altitudes ?3-4 km with extremely low abundance. We exposed an appropriate passive detector to cosmic rays at Darjeeling, India, at an atmospheric pressure of 765 hPa, as a pilot study to determine its suitability for the detection of strangelets in a large area detector array through long-term exposure. During the analysis we found a highly unusual event consisting of a cluster of six identical nuclear tracks. We argue that even the most mundane explanation of this event requires unusual physics, the first possible observation of multifragmentation involving cosmic rays.

Basu, Basudhara; Raha, Sibaji; Saha, Swapan K.; Biswas, Sukumar; Dey, Sandhya; Maulik, Atanu; Mazumdar, Amal; Saha, Satyajit; Syam, Debapriyo

2015-02-01

145

Propagation of cosmic rays in the galaxy  

NASA Technical Reports Server (NTRS)

The characteristics of a model for analyzing the propagation of cosmic rays are discussed. The requirements for analyzing the relevant observational data on cosmic rays are defines as: (1) the chemical and isotopic composition of cosmic rays as a function of energy, (2) the flux and energy spectrum of the individual nucleonic components, (3) the flux and energy spectrum of the electronic component, (4) the cosmic ray prehistory, and (5) the degree of isotropy in their arrival directions as a function of energy. It is stated that the model which has been able to bring to pass the greatest measure of success is the galactic confinement model.

Daniel, R. R.; Stephens, S. A.

1974-01-01

146

A hysteresis effect in cosmic ray modulation  

NASA Technical Reports Server (NTRS)

The rigidity dependence is investigated in the modulation of cosmic ray protons and alphas at intermediate (2-13 Gv) rigidities during the declines and recoveries of the cosmic ray flux near cosmic ray minimum. The results include the finding that sudden changes in the modulation of the primary cosmic rays are initiated by large solar particle outflow and begin as type I Forbush decreases. Typically, the modulation spectrum becomes flatter at intermediate rigidity below 13 Gv and steeper at rigidities above 13 Gv during early recovery.

Verschell, H. J.; Mendell, R. B.; Korff, S. A.

1974-01-01

147

The Interstellar Transport of Galactic Cosmic Rays.  

E-print Network

??Using the Cosmic Ray Isotope Spectrometer: CRIS) onboard the Advanced Composition Explorer: ACE) spacecraft, new and improved high-precision measurements of the elemental composition and energy (more)

Lave, Kelly

2012-01-01

148

EMMA - an underground cosmic-ray experiment  

NASA Astrophysics Data System (ADS)

A new cosmic-ray experiment is under construction in the Pyhsalmi mine, Finland. It aims to study the (mass) composition of cosmic rays at and above the knee region. The array, called EMMA (Experiment with MultiMuon Array), will cover approximately 130 m 2 of detector area at a depth of 75 metres (~210 mwe). It is able to locate shower cores in an area of approximately 400 m 2 with an accuracy better than 6 metres. The array detects underground muons and the muon multiplicity, their lateral distribution and the arrival direction of the air shower can be determined. First scientific measurements can be started during the spring 2009 with a partial-size array. The full-size array is expected to be ready by autumn 2010. The full-size array consist of two type of detectors: drift chambers and plastic scintillation detectors. Besides the composition study, it is also expected that the array contributes on the study of high-multiplicity muon bundles that were observed at the cosmic-ray experiments at the LEP detectors.

Enqvist, T.; Bezrukov, L.; Fynbo, H.; Heikkil, E.; Inzhechik, L.; Joutsenvaara, J.; Jones, P.; Jmsn, T.; Kalliokoski, T.; Kernen, P.; Kolos, K.; Kuusiniemi, P.; Lubsandorzhiev, B.; Olanter, L.; Petkov, V.; Rih, T.; Sarkamo, J.; Trzaska, W.; Usoskin, I.

2009-12-01

149

Cosmic ray modulation by interplanetary disturbances  

NASA Astrophysics Data System (ADS)

Interplanetary disturbances such as ICMEs (Interplanetary Coronal Mass Ejections) and CIRs (Corotating Interaction Regions), modulate high-energy cosmic rays reaching the Earth. Prior to the arrival of the disturbances at the Earth, ground based high-energy muon detectors can detect precursory effects in cosmic-ray anisotropy, such as precursory deficit and/or excess of intensity along the sunward IMF (Interplanetary Magnetic Field) direction. With suitable analyses, these precursors are found typically around 8 hours prior to the disturbance arrival at the Earth. The objective of this work is to analyze these precursors by using the Global Muon Detector Network (GMDN), an international network formed by four multidirectional muon detectors viewing a full range of the pitch angle measured from the sunward IMF direction. By analyzing the variation of the count rate global distribution of the observed intensity (instead of analyzing the count rate) precursory signatures can be enhanced when compared with analyses of count rates. For some events, it is possible to make almost a global distribution map of cosmic ray density using all the directional channels of the detectors. Precursory signature is generally accompanied by the interplanetary shock, but there are also some signatures not associated with the shock.

Braga, Carlos Roberto; Dal Lago, Alisson; Schuch, Nelson Jorge; da Silva, Marlos; Echer, Ezequiel; Demtrio Gonzalez Alarcon, Walter; Munakata, Kazuoki; Kuwabara, Takao; Kato, Chihiro; Bieber, John W.

150

Cosmic Ray Energetics and Mass (CREAM)  

NASA Technical Reports Server (NTRS)

The CREAM instrument was flown on a Long Duration Balloon in Antarctica in December 2004 and January 2005, achieving a flight duration record of nearly 42 days. It detected and recorded cosmic ray primary particles ranging in type from hydrogen to iron nuclei and in energy from 1 TeV to several hundred TeV. With the data collected we will have the world's best measurement of the energy spectra and mass composition of nuclei in the primary cosmic ray flux at these energies, close to the astrophysical knee . The instrument utilized a thin calorimeter, a transition radiation detector and a timing charge detector, which also provided time-of-flight information. The responsibilities of our group have been with the timing charge detector (TCD), and with the data acquisition electronics and ground station support equipment. The TCD utilized fast scintillators to measure the charge of the primary cosmic ray before any interactions could take place within the calorimeter. The data acquisition electronics handled the output of the various detectors, in a fashion fully integrated with the payload bus. A space-qualified flight computer controlled the acquisition, and was used for preliminary trigger information processing and decision making. Ground support equipment was used to monitor the health of the payload, acquire and archive the data transmitted to the ground, and to provide real-time control of the instrument in flight.

Coutu, Stephane

2005-01-01

151

Invariance Violation Extends the Cosmic Ray Horizon ?  

E-print Network

We postulate in the present paper that the energy-momentum relation is modified for very high energy particles to violate Lorentz invariance and the speed of photon is changed from the light velocity c. The violation effect is amplified, in a sensitive way to detection, through the modified kinematical constraints on the conservation of energy and momentum, in the absorption process of gamma-rays colliding against photons of longer wavelengths and converting into an electron-positron pair. For gamma-rays of energies higher than 10 TeV, the minimum energy of the soft photons for the reaction and then the absorption mean free path of gamma-rays are altered by orders of magnitude from the ones conventionally estimated. Consideration is similarly applied to high energy cosmic ray protons. The consequences may require the standard assumptions on the maximum distance that very high energy radiation can travel from to be revised.

T. Kifune

1999-04-13

152

Cosmic ray diffusion: Report of the Workshop in Cosmic Ray Diffusion Theory  

NASA Technical Reports Server (NTRS)

A workshop in cosmic ray diffusion theory was held at Goddard Space Flight Center on May 16-17, 1974. Topics discussed and summarized are: (1) cosmic ray measurements as related to diffusion theory; (2) quasi-linear theory, nonlinear theory, and computer simulation of cosmic ray pitch-angle diffusion; and (3) magnetic field fluctuation measurements as related to diffusion theory.

Birmingham, T. J.; Jones, F. C.

1975-01-01

153

[gamma]-ray bursts from ordinary cosmic strings  

SciTech Connect

We give an upper estimate for the number of [gamma]-ray bursts from ordinary (nonsuperconducting) cosmic strings expected to be observed at terrestrial detectors. Assuming that cusp annihilation is the mechanism responsible for the bursts we consider strings arising at a GUT phase transition and compare our estimate with the recent BATSE results. Further we give a lower limit for the effective area of future detectors designed to detect the cosmic-string-induced flux of [gamma]-ray bursts.

Brandenberger, R.H.; Sornborger, A.T.; Trodden, M. (Department of Physics, Brown University, Providence, Rhode Island 02912 (United States))

1993-07-15

154

Strangelets accelerated by pulsars in galactic cosmic rays  

E-print Network

It is shown that nuggets of strange quark matter may be extracted from the surface of pulsars and accelerated by strong electric fields to high energies if pulsars are strange stars with the crusts, comprised of nuggets embedded in a uniform electron background. Such high energy nuggets called usually strangelets give an observable contribution into galactic cosmic rays and may be detected by the upcoming cosmic ray experiment Alpha Magnetic Spectrometer AMS-02 on the International Space Station.

K. S. Cheng; V. V. Usov

2006-10-09

155

Detection of reflected Cherenkov light from extensive air showers in the SPHERE experiment as a method of studying superhigh energy cosmic rays  

NASA Astrophysics Data System (ADS)

Although a large number of experiments were carried out during the last few decades, the uncertainty in the spectrum of all nuclei of primary cosmic rays (PCRs) with superhigh energies is still high, and the results of many experiments on nuclear composition of PCRs are contradictory. An overview of the SPHERE experiment on detecting Vavilov-Cherenkov radiation from extensive air shower (EAS) reflected from a ground snow surface is given. A number of experimental studies implementing this method are presented and their results are analyzed. Some other popular methods of studying PCRs with superhigh energies ( E 0 > 1015 eV) and their main advantages and drawbacks are briefly considered. The detecting equipment of the SPHERE-2 experiment and the technique of its calibration are considered. The optical properties of snow, which are important for experiments on reflected Cherenkov light (CL) from EAS, are discussed and the history of observing reflected EAS CL is described. The algorithm of simulating the detector response and calculating the fiducial acceptance of shower detection is described. The procedure of processing the experimental data with a subsequent reconstruction of the spectrum of all PCR nuclei and analysis of the mass composition is shown. The first results of reconstructing the spectrum and separating groups of cosmic-ray nuclei with high energies in the SPHERE-2 experiment are presented. Main sources of systematic errors are considered. The prospects of developing the technique of observation of reflected EAS CL in future experiments are discussed.

Antonov, R. A.; Aulova, T. V.; Bonvech, E. A.; Galkin, V. I.; Dzhatdoev, T. A.; Podgrudkov, D. A.; Roganova, T. M.; Chernov, D. V.

2015-01-01

156

Studies of Cosmic Rays with GeV Gamma Rays  

E-print Network

We describe the role of GeV gamma-ray observations with GLAST-LAT (Gamma-ray Large Area Space Telescope - Large Area Telescope) in identifying interaction sites of cosmic-ray proton (or hadrons) with interstellar medium (ISM). We expect to detect gamma rays from neutral pion decays in high-density ISM regions in the Galaxy, Large Magellanic Cloud, and other satellite galaxies. These gamma-ray sources have been detected already with EGRET (Energetic Gamma Ray Experiment Telescope) as extended sources (eg. LMC and Orion clouds) and GLAST-LAT will detect many more with a higher spatial resolution and in a wider spectral range. We have developed a novel image restoration technique based on the Richardson-Lucy algorithm optimized for GLAST-LAT observation of extended sources. Our algorithm calculates PSF (point spread function) for each event. This step is very important for GLAST-LAT and EGRET image analysis since PSF varies more than one order of magnitude from one gamma ray to another depending on its energy as well as its impact point and angle in the instrument. The GLAST-LAT and EGRET image analysis has to cope with Poisson fluctuation due to low number of detected photons for most sources. Our technique incorporates wavelet filtering to minimize effects due to the fluctuation. Preliminary studies on some EGRET sources are presented, which shows potential of this novel image restoration technique for the identification and characterisation of extended gamma-ray sources.

Hiroyasu Tajima; Tuneyoshi Kamae; Stefano Finazzi; Johann Cohen-Tanugi; James Chiang

2007-05-10

157

Pionic Photons and Neutrinos from Cosmic Ray Accelerators  

E-print Network

Identifying the accelerators that produce the Galactic and extragalactic cosmic rays has been a priority mission of several generations of high energy gamma ray and neutrino telescopes; success has been elusive so far. Detecting the gamma-ray and neutrino fluxes associated with cosmic rays reaches a new watershed with the completion of IceCube, the first neutrino detector with sensitivity to the anticipated fluxes, and the construction of CTA, a ground-based gamma ray detector that will map and study candidate sources with unprecedented precision. In this paper, we revisit the prospects for revealing the sources of the cosmic rays by a multiwavelength approach; after reviewing the methods, we discuss supernova remnants, gamma ray bursts, active galaxies and GZK neutrinos in some detail.

Francis Halzen

2011-11-04

158

Cosmic rays and space weather  

NASA Astrophysics Data System (ADS)

It is well known that in periods of great FEP (Flare Energetic Particle), fluxes can be so big that memory of computers and other electronics in space may be destroyed, satellites and spacecrafts became dead (each year insurance companies paid more than 500,000,000 dollars for these failures). In these periods is necessary to switch off some part of electronics for short time to protect computer memories. These periods are also dangerous for astronauts on space-ships, and passengers and crew in commercial jets (especially during S5 radiation storms according to classification of NOAA). The problem is how to forecast exactly these dangerous phenomena. We show that exact forecast can be made by using high-energy particles (about 5-10 GeV/nucleon and higher) which transportation from the Sun is characterized by much bigger diffusion coefficient than for small and middle energy particles. Therefore high energy particles came from the Sun much more early (8-20 minutes after acceleration and escaping into solar wind) than main part of smaller energy particles caused dangerous situation for electronics and people health (about 30-60 minutes later). We describe here principles and experience of automatically working programs "FEP-Search-1 min", "FEP-Search-2 min","FEP-Search-5 min", developed and checked in the Emilio Segre' Observatory of Israel Cosmic Ray Center (2025 m above sea level, cut-off rigidity 10.8 GV). The second step is automatically determination of flare energetic particle spectrum, and then automatically determination of diffusion coefficient in the interplanetary space, time of ejection and energy spectrum of FEP in source; forecasting of expected FEP flux and radiation hazard for space-probes in space, satellites in the magnetosphere, jets and various objects in the atmosphere and on the ground. We will describe also the theory and experience of high energy cosmic ray using for forecasting of major geomagnetic storms accompanied by Forbush-effects (what influenced very much on communications, working of navigation systems, satellites and high-level technology systems in space and, the atmosphere, and on the ground). The review and original part will contain following parts: 1. Introduction (cosmic rays as object and instrument of space weather monitoring and forecasting). 2. On-line search of the start of great Flare Energetic Particle (FEP) events, automatically formation of Alerts, estimation of probability of false alerts and probability of missing alerts (realized in Israel Cosmic Ray Center and Emilio Segre Observatory). 3. On-line determination of flare energetic particle spectrum by the method of coupling functions. 4. Automatically determination of diffusion coefficient in the interplanetary space, time of ejection and energy spectrum of FEP in source; forecasting of expected FEP flux and radiation hazard for space-probes in space, satellites in the magnetosphere, jets and various objects in the atmosphere, and on the ground in dependence of cut-off rigidity. 5. Cosmic ray using for forecasting of major geomagnetic storms accompanied by Forbush-effects.

Dorman, L. I.

2003-04-01

159

The highest-energy cosmic rays  

Microsoft Academic Search

Some cosmic-ray particles have an energy far higher than that of the fast particles generated by the largest accelerating machines yet built. The most energetic cosmic rays observed so far have had energies of two or three times 10 to the 20th power electron volts. Difficulties concerning the study of these particles are related to the very low intensity of

John Linsley

1978-01-01

160

The Discovery and Nature of Cosmic Rays  

NSDL National Science Digital Library

In this lesson, students will learn how cosmic rays were discovered and what they are - including their size and speed. Includes background information for the teacher, questions, activities and information about student preconceptions. This is lesson 1 of 4 from "The Cosmic Ray Telescope for the Effects of Radiation (CRaTER)."

2012-08-03

161

Cosmic-ray detectors on the Moon  

NASA Technical Reports Server (NTRS)

The state of cosmic ray physics is reviewed. It is concluded that the nonexistent lunar magnetic field, the low lunar radiation background, and the lack of an atmosphere on the Moon provide an excellent environment for the study of high energy primary cosmic rays.

Linsley, John

1988-01-01

162

Electromagnetic interactions of cosmic rays with nuclei  

NASA Technical Reports Server (NTRS)

Parameterizations of single nucleon emission from the electromagnetic interactions of cosmic rays with nuclei are presented. These parameterizations are based upon the most accurate theoretical calculations available today. When coupled with Strong interaction parameterizations, they should be very suitable for use in cosmic ray propagation through intersteller space, the Earth's atmosphere, lunar samples, meteorites and spacecraft walls.

Norbury, John W.

1989-01-01

163

Satellite Anomalies from Galactic Cosmic Rays  

Microsoft Academic Search

Anomalies in communication satellite operation have been caused by the unexpected triggering of digital circuits. Interactions with galactic cosmic rays were investigated as a mechanism for a number of these events. The mechanism assumed was the charging of the base-emitter capacitance of sensitive transistors to the turn-on voltage. The calculation of the cosmic ray event rate required the determination of

D. Binder; E. C. Smith; A. B. Holman

1975-01-01

164

Low Cloud Properties Influenced by Cosmic Rays  

Microsoft Academic Search

The influence of solar variability on climate is currently uncertain. Recent observations have indicated a possible mechanism via the influence of solar modulated cosmic rays on global cloud cover. Surprisingly the influence of solar variability is strongest in low clouds \\\\(<=3 km\\\\), which points to a microphysical mechanism involving aerosol formation that is enhanced by ionization due to cosmic rays.

Nigel D. Marsh; Henrik Svensmark

2000-01-01

165

Influence of Cosmic Rays on Earth's Climate  

Microsoft Academic Search

During the last solar cycle Earth's cloud cover underwent a modulation more closely in phase with the galactic cosmic ray flux than with other solar activity parameters. Further it is found that Earth's temperature follows more closely decade variations in galactic cosmic ray flux and solar cycle length, than other solar activity parameters. The main conclusion is that the average

Henrik Svensmark

1998-01-01

166

Cosmic Rays on the Pacific Ocean  

Microsoft Academic Search

Records of cosmic-ray intensity obtained on the R. M. S. Aorangi during 12 voyages between Vancouver, Canada and Sydney, Australia, from March 17, 1936, to January 18, 1937, using a Carnegie model C cosmic-ray meter, are described and discussed. Typical records exhibiting the latitude effect are shown. A summary of the data taken at sea is given in the form

A. H. Compton; R. N. Turner

1937-01-01

167

Superdiffusion of Cosmic Rays: Implications for Cosmic Ray Acceleration  

E-print Network

Diffusion of cosmic rays (CRs) is the key process of understanding their propagation and acceleration. We employ the description of spatial separation of magnetic field lines in MHD turbulence in Lazarian & Vishniac (1999) to quantify the divergence of magnetic field on scales less than the injection scale of turbulence and show this divergence induces superdiffusion of CR in the direction perpendicular to the mean magnetic field. The perpendicular displacement squared increases, not as distance $x$ along magnetic field, which is the case for a regular diffusion, but as the $x^{3}$ for freely streaming CRs. The dependence changes to $x^{3/2}$ for the CRs propagating diffusively along magnetic field. In the latter case we show that it is important to distinguish the perpendicular displacement in respect to the mean field and to the local magnetic field. We consider how superdiffusion changes the acceleration of CRs in shocks and show how it decreases efficiency of the CRs acceleration in perpendicular shoc...

Lazarian, A

2013-01-01

168

High energy physics in cosmic rays  

SciTech Connect

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

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

2013-02-07

169

Measuring Cosmic Rays at 1 PeV and Above  

NASA Astrophysics Data System (ADS)

High energy cosmic rays arrive at Earth's upper atmosphere from all directions with a remarkably smooth power-law spectrum. Structures in this otherwise smooth spectrum (such as changes in slope or in chemical composition) give clues as to the sources, acceleration, and propagation of these particles. At energies beyond 1 PeV, as cosmic rays become too rare for direct measurements to be practical, large ground-based experiments make indirect measurements of cosmic ray air showers. They employ a wide range of detection technologies and techniques, exploring known features in the spectrum such as the "knee" and the "ankle", as well as searching for new clues in the energy spectrum, chemical composition, and anisotropy in arrival directions of these particles. This talk will overview the broad landscape of ground-based cosmic ray detector arrays, and will focus on the IceCube Observatory at the South Pole.

Rawlins, Katherine

2012-05-01

170

Cosmic rays: a review for astrobiologists.  

PubMed

Cosmic rays represent one of the most fascinating research themes in modern astronomy and physics. Significant progress is being made toward an understanding of the astrophysics of the sources of cosmic rays and the physics of interactions in the ultrahigh-energy range. This is possible because several new experiments in these areas have been initiated. Cosmic rays may hold answers to a great number of fundamental questions, but they also shape our natural habitat and influence the radiation environment of our planet Earth. The importance of the study of cosmic rays has been acknowledged in many fields, including space weather science and astrobiology. Here, we concentrate on the astrobiological aspects of cosmic rays with regard to the enormous amount of new data available, some of which may, in fact, improve our knowledge about the radiation of cosmic origin on Earth. We focus on fluxes arriving at Earth and doses received, and will guide the reader through the wealth of scientific literature on cosmic rays. We have prepared a concise and self-contained source of data and recipes useful for performing interdisciplinary research in cosmic rays and their effects on life on Earth. PMID:19519216

Ferrari, Franco; Szuszkiewicz, Ewa

2009-05-01

171

High-Energy Cosmic Rays and Neutrinos from Gamma-Ray Bursts  

E-print Network

A complete model for the origin of high-energy >~10^{14} eV) cosmic rays from gamma-ray bursts (GRBs) and implications of this hypothesis are described. Detection of high-energy neutrinos from GRBs provide an unambiguous test of the model. Evidence for cosmic-ray acceleration in GRBs is suggested by the detection of anomalous gamma-ray components such as that observed from GRB 941017. Neutron beta-decay halos around star-forming galaxies such as the Milky Way are formed as a consequence of this model. Cosmic rays from GRBs in the Galaxy are unlikely to account for the ~10^{18} eV cosmic-ray excess reported by the Sydney University Giant Air Shower Recorder (SUGAR), but could contribute to past extinction events.

C. Dermer

2005-06-16

172

Tomographic-spectral approach for dark matter detection in the cross-correlation between cosmic shear and diffuse gamma-ray emission  

E-print Network

We recently proposed to cross-correlate the diffuse gamma-ray emission with the gravitational lensing signal of cosmic shear. This represents a novel and promising strategy to search for annihilating or decaying dark matter (DM) candidates. In the present work, we demonstrate the potential of a tomographic-spectral approach: measuring the cross-correlation in separate bins of redshift and energy significantly improves the sensitivity to a DM signal. Indeed, the power of the proposed technique stems from the capability of simultaneously exploiting the different redshift scaling of astrophysical and DM components, their different energy spectra and their different angular shapes. The sensitivity to a particle DM signal is extremely promising even in the case the gamma-ray emission induced by DM is a subdominant component in the isotropic gamma-ray background. We quantify the prospects of detecting DM by cross-correlating the gamma-ray emission from the Fermi large area telescope (LAT) with the cosmic shear measured by the Dark Energy Survey, using data sets that will be available in the near future. Under the hypothesis of a significant (but realistic) subhalo boost, such a measurement can deliver a 5-sigma detection of DM, if the DM particle has a mass lighter than 300 GeV and thermal annihilation rate. Data from the European Space Agency Euclid satellite (launch planned for 2020) will be even more informative: if used to reconstruct the properties of the DM particle, the cross-correlation of Euclid and Fermi-LAT will allow for a measurement of the DM mass within a factor of 1.5-2, even for moderate subhalo boosts, assuming the DM mass around 100 GeV and a thermal annihilation rate.

Stefano Camera; Mattia Fornasa; Nicolao Fornengo; Marco Regis

2014-11-17

173

SLAC Cosmic Ray Telescope Facility  

SciTech Connect

SLAC does not have a test beam for the HEP detector development at present. We have therefore created a cosmic ray telescope (CRT) facility, which is presently being used to test the FDIRC prototype. We have used it in the past to debug this prototype with the original SLAC electronics before going to the ESA test beam. Presently, it is used to test a new waveform digitizing electronics developed by the University of Hawaii, and we are also planning to incorporate the new Orsay TDC/ADC electronics. As a next step, we plan to put in a full size DIRC bar box with a new focusing optics, and test it together with a final SuberB electronics. The CRT is located in building 121 at SLAC. We anticipate more users to join in the future. This purpose of this note is to provide an introductory manual for newcomers.

Va'vra, J.

2010-02-15

174

Cosmic gamma-ray bursts  

NASA Technical Reports Server (NTRS)

A review of the cosmic gamma-ray burst phenomenon is presented. Both the light curves and the energy spectra of these short transient events display a great diversity. However, rapid rise times and periodicities sometimes observed in the light curves suggest a compact object origin. Similarly, absorption and emission features in the energy spectra argue strongly in favor of this interpretation. Counterparts to gamma-bursters in other energy ranges, such as optical and sort x-ray, have still not been identified, however, leading to a large uncertainty in the distances to bursters. Although gamma-ray burst sources have not yet been observed to repeat, numerous bursts from three objects which may be related to the gamma-bursters, called Soft Gamma Repeaters, have been recorded; there is weak evidence that they may be relatively distant on a galactic scale. Future missions, particularly those emphasizing high energy, time, and/or spatial resolution, as well as a multiwavelength approach, are likely to advance our understanding of this enigmatic phenomenon.

Hurley, K.

1991-01-01

175

Lunar monitoring outpost of cosmic rays  

NASA Astrophysics Data System (ADS)

The basic purpose of the planned NEUTRONIUM-100 experiment considers expansion of the direct measurements of cosmic rays spectra and anisotropy to the energy range of ~1017 eV with element-by-element resolution of the nuclear component. These measurements will make it possible to solve the problem of the knee of the spectrum and to make choice between the existing models of the cosmic rays origin and propagation. The proposed innovative method of energy measurements is based on the simultaneous detection of different components of back scattered radiation generated by showers produced by the primary particle in the regolyth (neutrons, gamma rays and radio waves). A multi-module system disposed on the Moon's surface is proposed for particles registration. Each module consists of a radio antenna, contiguous to the regolyth, scintillation detectors with gadolinium admixture and silicon charge detectors. Scintillation detectors record electrons and gamma-rays of back scattered radiation and delayed neutrons. The area of the experimental facility will be at least ~100 m2, suitable for upgrading. Average density of the detecting equipment is evaluated as 10-20 g/m2. Taking into account the weight of the equipment delivered from the Earth will be about 10 tons it is possible to compose an eqperimental facility with geometric factor of 150-300 m2sr. The Moon provides unique conditions for this experiment due to presence of the absorbing material and absence of atmosphere. The experiment will allow expansion of the measurements up to ~1017 eV with element-by-element resolution of the nuclear component. Currently direct measurements reach energy range of up to ~1015 eV, and Auger shower method does not provide information about the primary particle's charge. It is expected that ~15 particles with energy >1017 eV will be detected by the proposed experimental equipment per year. It will provide an opportunity to solve the problems of the current high-energy astrophysics.

Panasyuk, Mikhail; Kalmykov, Nikolai; Turundaevskiy, Andrey; Chubenko, Alexander; Podorozhny, Dmitry; Mukhamedshin, Rauf; Sveshnikova, Lubov; Tkachev, Leonid; Konstantinov, Andrey

176

Cosmic Rays from Gamma Ray Bursts in the Galaxy  

E-print Network

The rate of terrestrial irradiation events by galactic gamma-ray bursts (GRBs) is estimated using recent standard-energy results. We assume that GRBs accelerate high-energy cosmic rays, and present results of three-dimensional simulations of cosmic rays moving in the Galactic magnetic field and diffusing through pitch-angle scattering. An on-axis GRB extinction event begins with a powerful prompt gamma-ray and neutron pulse, followed by a longer-lived phase from cosmic-ray protons and neutron-decay protons that diffuse towards Earth. Our results force a reinterpretation of reported ~ 10^{18} eV cosmic-ray anisotropies and offer a rigorous test of the model where high-energy cosmic rays originate from GRBs, which will soon be tested with the Auger Observatory.

Charles D. Dermer; Jeremy M. Holmes

2005-06-16

177

30TH INTERNATIONAL COSMIC RAY CONFERENCE Stochastic simulation of cosmic ray modulation: Effect of a wavy HCS  

E-print Network

30TH INTERNATIONAL COSMIC RAY CONFERENCE Stochastic simulation of cosmic ray modulation: Effect of the heliospheric transport of galactic cosmic rays. Using an analytical solution for the flat sheet, we apply ray spectrum and the dominant streaming patterns of cosmic rays in the heliosphere for different solar

Usoskin, Ilya G.

178

Cosmogenic gamma rays and the composition of cosmic rays  

SciTech Connect

We discuss the prospects of detecting the sources of ultrahigh energy (UHE) cosmic ray (CR) nuclei via their emission of cosmogenic {gamma} rays in the GeV to TeV energy range. These {gamma} rays result from electromagnetic cascades initiated by high energy photons, electrons, and positrons that are emitted by CRs during their propagation in the cosmic radiation background and are independent of the simultaneous emission of {gamma} rays in the vicinity of the source. The corresponding production power by UHE CR nuclei (with mass number A and charge Z) is dominated by pion photo production ({proportional_to}A) and Bethe-Heitler pair production ({proportional_to}Z{sup 2}). We show that the cosmogenic {gamma}-ray signal from a single steady UHE CR source is typically more robust with respect to variations of the source composition and injection spectrum than the accompanying signal of cosmogenic neutrinos. We study the diffuse emission from the sum of extragalactic CR sources as well as the point-source emission of the closest sources.

Ahlers, Markus [C. N. Yang Institute for Theoretical Physics, SUNY at Stony Brook, Stony Brook, New York 11794-3840 (United States); Salvado, Jordi [Departament d'Estructura i Constituents de la Materia and Institut de Ciencies del Cosmos, Universitat de Barcelona, 647 Diagonal, E-08028 Barcelona (Spain)

2011-10-15

179

DISTINGUISHING SPONTANEOUS FISSION NEUTRONS FROM COSMIC-RAY BACKGROUND.  

SciTech Connect

We have measured the neutron spectra of cosmic-rays and a spontaneous fission emitting source (Cf-252) using a neutron double scatter spectrometer. The energy range of measurements was 0.1-10 MeV where the spectrometer efficiency is determined to be up to 8.7% depending on the separation between detection planes. Our cosmic-ray neutron spectrum measurement is in good agreement with the sea-level data reported by Goldhagen and his co-workers. In the energy range 0.1-1.0 MeV, the cosmic-ray and Cf-252 spectra are different and separable. This difference is expected from the applicable models that describe the phenomena, ''equilibrium slowing down'' (cosmic-rays) and ''Maxwellian kinetic temperature'' emission (spontaneous fission). We show that >80% of Cf-252 neutrons and <25% of cosmic-ray related neutrons are emitted in this energy range of measurement, and conclude that neutron spectroscopy provides effective ways to distinguish a fission source from the cosmic-ray background.

FORMAN,L.

2004-08-02

180

The Lateral Trigger Probability function for the Ultra-High Energy Cosmic Ray Showers detected by the Pierre Auger Observatory  

E-print Network

In this paper we introduce the concept of Lateral Trigger Probability (LTP) function, i.e., the probability for an extensive air shower (EAS) to trigger an individual detector of a ground based array as a function of distance to the shower axis, taking into account energy, mass and direction of the primary cosmic ray. We apply this concept to the surface array of the Pierre Auger Observatory consisting of a 1.5 km spaced grid of about 1600 water Cherenkov stations. Using Monte Carlo simulations of ultra-high energy showers the LTP functions are derived for energies in the range between 10^{17} and 10^{19} eV and zenith angles up to 65 degs. A parametrization combining a step function with an exponential is found to reproduce them very well in the considered range of energies and zenith angles. The LTP functions can also be obtained from data using events simultaneously observed by the fluorescence and the surface detector of the Pierre Auger Observatory (hybrid events). We validate the Monte-Carlo results showing how LTP functions from data are in good agreement with simulations.

The Pierre Auger Collaboration; P. Abreu; M. Aglietta; E. J. Ahn; I. F. M. Albuquerque; D. Allard; I. Allekotte; J. Allen; P. Allison; J. Alvarez Castillo; J. Alvarez-Muiz; M. Ambrosio; A. Aminaei; L. Anchordoqui; S. Andringa; T. Anti?i?; A. Anzalone; C. Aramo; E. Arganda; F. Arqueros; H. Asorey; P. Assis; J. Aublin; M. Ave; M. Avenier; G. Avila; T. Bcker; M. Balzer; K. B. Barber; A. F. Barbosa; R. Bardenet; S. L. C. Barroso; B. Baughman; J. Buml; J. J. Beatty; B. R. Becker; K. H. Becker; A. Belltoile; J. A. Bellido; S. BenZvi; C. Berat; X. Bertou; P. L. Biermann; P. Billoir; F. Blanco; M. Blanco; C. Bleve; H. Blmer; M. Boh?ov; D. Boncioli; C. Bonifazi; R. Bonino; N. Borodai; J. Brack; P. Brogueira; W. C. Brown; R. Bruijn; P. Buchholz; A. Bueno; R. E. Burton; K. S. Caballero-Mora; L. Caramete; R. Caruso; A. Castellina; O. Catalano; G. Cataldi; L. Cazon; R. Cester; J. Chauvin; S. H. Cheng; A. Chiavassa; J. A. Chinellato; A. Chou; J. Chudoba; R. W. Clay; M. R. Coluccia; R. Conceio; F. Contreras; H. Cook; M. J. Cooper; J. Coppens; A. Cordier; S. Coutu; C. E. Covault; A. Creusot; A. Criss; J. Cronin; A. Curutiu; S. Dagoret-Campagne; R. Dallier; S. Dasso; K. Daumiller; B. R. Dawson; R. M. de Almeida; M. De Domenico; C. De Donato; S. J. de Jong; G. De La Vega; W. J. M. de Mello Junior; J. R. T. de Mello Neto; I. De Mitri; V. de Souza; K. D. de Vries; G. Decerprit; L. del Peral; M. del Ro; O. Deligny; H. Dembinski; N. Dhital; C. Di Giulio; J. C. Diaz; M. L. Daz Castro; P. N. Diep; C. Dobrigkeit; W. Docters; J. C. D'Olivo; P. N. Dong; A. Dorofeev; J. C. dos Anjos; M. T. Dova; D. D'Urso; I. Dutan; J. Ebr; R. Engel; M. Erdmann; C. O. Escobar; J. Espadanal; A. Etchegoyen; P. Facal San Luis; I. Fajardo Tapia; H. Falcke; G. Farrar; A. C. Fauth; N. Fazzini; A. P. Ferguson; A. Ferrero; B. Fick; A. Filevich; A. Filip?i?; S. Fliescher; C. E. Fracchiolla; E. D. Fraenkel; U. Frhlich; B. Fuchs; R. Gaior; R. F. Gamarra; S. Gambetta; B. Garca; D. Garca Gmez; D. Garcia-Pinto; A. Gascon; H. Gemmeke; K. Gesterling; P. L. Ghia; U. Giaccari; M. Giller; H. Glass; M. S. Gold; G. Golup; F. Gomez Albarracin; M. Gmez Berisso; P. Gonalves; D. Gonzalez; J. G. Gonzalez; B. Gookin; D. Gra; A. Gorgi; P. Gouffon; S. R. Gozzini; E. Grashorn; S. Grebe; N. Griffith; M. Grigat; A. F. Grillo; Y. Guardincerri; F. Guarino; G. P. Guedes; A. Guzman; J. D. Hague; P. Hansen; D. Harari; S. Harmsma; J. L. Harton; A. Haungs; T. Hebbeker; D. Heck; A. E. Herve; C. Hojvat; N. Hollon; V. C. Holmes; P. Homola; J. R. Hrandel; A. Horneffer; M. Hrabovsk; T. Huege; A. Insolia; F. Ionita; A. Italiano; C. Jarne; S. Jiraskova; M. Josebachuili; K. Kadija; K. H. Kampert; P. Karhan; P. Kasper; B. Kgl; B. Keilhauer; A. Keivani; J. L. Kelley; E. Kemp; R. M. Kieckhafer; H. O. Klages; M. Kleifges; J. Kleinfeller; J. Knapp; D. -H. Koang; K. Kotera; N. Krohm; O. Krmer; D. Kruppke-Hansen; F. Kuehn; D. Kuempel; J. K. Kulbartz; N. Kunka; G. La Rosa; C. Lachaud; P. Lautridou; M. S. A. B. Leo; D. Lebrun; P. Lebrun; M. A. Leigui de Oliveira; A. Lemiere; A. Letessier-Selvon; I. Lhenry-Yvon; K. Link; R. Lpez; A. Lopez Agera; K. Louedec; J. Lozano Bahilo; L. Lu; A. Lucero; M. Ludwig; H. Lyberis; M. C. Maccarone; C. Macolino; S. Maldera; D. Mandat; P. Mantsch; A. G. Mariazzi; J. Marin; V. Marin; I. C. Maris; H. R. Marquez Falcon; G. Marsella; D. Martello; L. Martin; H. Martinez; O. Martnez Bravo; H. J. Mathes; J. Matthews; J. A. J. Matthews; G. Matthiae; D. Maurizio; P. O. Mazur; G. Medina-Tanco; M. Melissas; D. Melo; E. Menichetti; A. Menshikov; P. Mertsch; C. Meurer; S. Mi?anovi?; M. I. Micheletti; W. Miller; L. Miramonti; L. Molina-Bueno; S. Mollerach; M. Monasor; D. Monnier Ragaigne; F. Montanet; B. Morales; C. Morello; E. Moreno; J. C. Moreno; C. Morris; M. Mostaf; C. A. Moura; S. Mueller; M. A. Muller; G. Mller; M. Mnchmeyer; R. Mussa; G. Navarra ; J. L. Navarro; S. Navas; P. Necesal; L. Nellen; A. Nelles; J. Neuser; P. T. Nhung; L. Niemietz; N. Nierstenhoefer; D. Nitz; D. Nosek; L. Noka; M. Nyklicek; J. Oehlschlger; A. Olinto; P. Oliva; V. M. Olmos-Gilbaja; M. Ortiz; N. Pacheco; D. Pakk Selmi-Dei; M. Palatka; J. Pallotta; N. Palmieri; G. Parente; E. Parizot; A. Parra; R. D. Parsons; S. Pastor; T. Paul; M. Pech; J. P?kala; R. Pelayo; I. M. Pepe; L. Perrone; R. Pesce; E. Petermann; S. Petrera; P. Petrinca; A. Petrolini; Y. Petrov; J. Petrovic; C. Pfendner; N. Phan; R. Piegaia; T. Pierog; P. Pieroni; M. Pimenta; V. Pirronello; M. Platino; V. H. Ponce; M. Pontz; P. Privitera; M. Prouza; E. J. Quel; S. Querchfeld; J. Rautenberg; O. Ravel; D. Ravignani; B. Revenu; J. Ridky; S. Riggi; M. Risse; P. Ristori; H. Rivera; V. Rizi; J. Roberts; C. Robledo; W. Rodrigues de Carvalho; G. Rodriguez; J. Rodriguez Martino; J. Rodriguez Rojo

2011-11-28

181

The Lateral Trigger Probability function for the Ultra-High Energy Cosmic Ray Showers detected by the Pierre Auger Observatory  

E-print Network

In this paper we introduce the concept of Lateral Trigger Probability (LTP) function, i.e., the probability for an extensive air shower (EAS) to trigger an individual detector of a ground based array as a function of distance to the shower axis, taking into account energy, mass and direction of the primary cosmic ray. We apply this concept to the surface array of the Pierre Auger Observatory consisting of a 1.5 km spaced grid of about 1600 water Cherenkov stations. Using Monte Carlo simulations of ultra-high energy showers the LTP functions are derived for energies in the range between 10^{17} and 10^{19} eV and zenith angles up to 65 degs. A parametrization combining a step function with an exponential is found to reproduce them very well in the considered range of energies and zenith angles. The LTP functions can also be obtained from data using events simultaneously observed by the fluorescence and the surface detector of the Pierre Auger Observatory (hybrid events). We validate the Monte-Carlo results sho...

Abreu, P; Ahn, E J; Albuquerque, I F M; Allard, D; Allekotte, I; Allen, J; Allison, P; Castillo, J Alvarez; Alvarez-Muiz, J; Ambrosio, M; Aminaei, A; Anchordoqui, L; Andringa, S; Anti?i?, T; Anzalone, A; Aramo, C; Arganda, E; Arqueros, F; Asorey, H; Assis, P; Aublin, J; Ave, M; Avenier, M; Avila, G; Bcker, T; Balzer, M; Barber, K B; Barbosa, A F; Bardenet, R; Barroso, S L C; Baughman, B; Buml, J; Beatty, J J; Becker, B R; Becker, K H; Belltoile, A; Bellido, J A; BenZvi, S; Berat, C; Bertou, X; Biermann, P L; Billoir, P; Blanco, F; Blanco, M; Bleve, C; Blmer, H; Boh?ov, M; Boncioli, D; Bonifazi, C; Bonino, R; Borodai, N; Brack, J; Brogueira, P; Brown, W C; Bruijn, R; Buchholz, P; Bueno, A; Burton, R E; Caballero-Mora, K S; Caramete, L; Caruso, R; Castellina, A; Catalano, O; Cataldi, G; Cazon, L; Cester, R; Chauvin, J; Cheng, S H; Chiavassa, A; Chinellato, J A; Chou, A; Chudoba, J; Clay, R W; Coluccia, M R; Conceio, 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; 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; Junior, W J M de Mello; Neto, J R T de Mello; De Mitri, I; de Souza, V; de Vries, K D; Decerprit, G; del Peral, L; del Ro, M; Deligny, O; Dembinski, H; Dhital, N; Di Giulio, C; Diaz, J C; Castro, M L Daz; Diep, P N; Dobrigkeit, C; Docters, W; D'Olivo, J C; Dong, P N; Dorofeev, A; Anjos, J C dos; Dova, M T; D'Urso, D; Dutan, I; Ebr, J; Engel, R; Erdmann, M; Escobar, C O; Espadanal, J; Etchegoyen, A; Luis, P Facal San; Tapia, I Fajardo; Falcke, H; Farrar, G; Fauth, A C; Fazzini, N; Ferguson, A P; Ferrero, A; Fick, B; Filevich, A; Filip?i?, A; Fliescher, S; Fracchiolla, C E; Fraenkel, E D; Frhlich, U; Fuchs, B; Gaior, R; Gamarra, R F; Gambetta, S; Garca, B; Gmez, D Garca; Garcia-Pinto, D; Gascon, A; Gemmeke, H; Gesterling, K; Ghia, P L; Giaccari, U; Giller, M; Glass, H; Gold, M S; Golup, G; Albarracin, F Gomez; Berisso, M Gmez; Gonalves, P; Gonzalez, D; Gonzalez, J G; Gookin, B; Gra, D; Gorgi, A; Gouffon, P; Gozzini, S R; Grashorn, E; Grebe, S; Griffith, N; Grigat, M; Grillo, A F; Guardincerri, Y; Guarino, F; Guedes, G P; Guzman, A; Hague, J D; Hansen, P; Harari, D; Harmsma, S; Harton, J L; Haungs, A; Hebbeker, T; Heck, D; Herve, A E; Hojvat, C; Hollon, N; Holmes, V C; Homola, P; Hrandel, J R; Horneffer, A; Hrabovsk, M; Huege, T; Insolia, A; Ionita, F; Italiano, A; Jarne, C; Jiraskova, S; Josebachuili, M; Kadija, K; Kampert, K H; Karhan, P; Kasper, P; Kgl, 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; Krmer, O; Kruppke-Hansen, D; Kuehn, F; Kuempel, D; Kulbartz, J K; Kunka, N; La Rosa, G; Lachaud, C; Lautridou, P; Leo, M S A B; Lebrun, D; Lebrun, P; de Oliveira, M A Leigui; Lemiere, A; Letessier-Selvon, A; Lhenry-Yvon, I; Link, K; Lpez, R; Agera, A Lopez; Louedec, K; Bahilo, J Lozano; Lu, L; Lucero, A; Ludwig, M; Lyberis, H; Maccarone, M C; Macolino, C; Maldera, S; Mandat, D; Mantsch, P; Mariazzi, A G; Marin, J; Marin, V; Maris, I C; Falcon, H R Marquez; Marsella, G; Martello, D; Martin, L; Martinez, H; Bravo, O Martnez; Mathes, H J; Matthews, J; Matthews, J A J; Matthiae, G; Maurizio, D; Mazur, P O; Medina-Tanco, G; Melissas, M; Melo, D; Menichetti, E; Menshikov, A; Mertsch, P; Meurer, C; Mi?anovi?, S; Micheletti, M I; Miller, W; Miramonti, L; Molina-Bueno, L; Mollerach, S; Monasor, M; Ragaigne, D Monnier; Montanet, F; Morales, B; Morello, C; Moreno, E; Moreno, J C; Morris, C; Mostaf, M; Moura, C A; Mueller, S; Muller, M A; Mller, G; Mnchmeyer, M; Mussa, R; , G Navarra; Navarro, J L; Navas, S; Necesal, P; Nellen, L; Nelles, A; Neuser, J; Nhung, P T; Niemietz, L; Nierstenhoefer, N; Nitz, D; Nosek, D; Noka, L; Nyklicek, M; Oehlschlger, J; Olinto, A; Oliva, P; Olmos-Gilbaja, V M; Ortiz, M; Pacheco, N; Selmi-Dei, D Pakk; Palatka, M; Pallotta, J; Palmieri, N; Parente, G; Parizot, E; Parra, A; Parsons, R D; Pastor, S; Paul, T; Pech, M; P?kala, J; Pelayo, R; Pepe, I M; Perrone, L; Pesce, R; Petermann, E; Petrera, S; Petrinca, P; Petrolini, A; Petrov, Y; Petrovic, J; Pfendner, C; Phan, N; Piegaia, R; Pierog, T; Pieroni, P; Pimenta, M; Pirronello, V; Platino, M; Ponce, V H; Pontz, M; 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; Robledo, C; de Carvalho, W Rodrigues; Rodriguez, G; Martino, J Rodriguez; Rojo, J Rodriguez; Rodriguez-Cabo, I; Rodrguez-Fras, M D; Ros, G; Rosado, J; Rossler, T; Roth, M; Rouill-d'Orfeuil, B; Roulet, E; Rovero, A C; Rhle, C; Salamida, F

2011-01-01

182

Cosmic Rays Variations and Human Physiological State  

NASA Astrophysics Data System (ADS)

It was obtained in our previous investigations that geomagnetic activity as an indirect indicator of solar activity correlates with some human physiological and psycho-physiological parameters. A lot of studies indicate that other parameters of space weather like cosmic rays Forbush decreases affect myocardial infarction, brain stroke, car accidents, etc. The purpose of that work was to study the effect of cosmic rays variations on human physiological status. It was established that the decrease in cosmic rays intensity was related to an increase in systolic and diastolic blood pressure and reported subjective psycho-physiological complaints in healthy volunteers.

Dimitrova, S.

2009-12-01

183

Cosmic ray propagation in the local superbubble  

NASA Technical Reports Server (NTRS)

It is suggested that a ring of HI gas lying in the galactic plane is part of a supershell which formed some 3 x to the 7th power years ago. The consequences of a closed magnetic supershell for cosmic ray propagation are examined and it is concluded that there is no evidence which precludes the production and trapping of cosmic rays in such a region. A consequence of superbubble confinement is that the mean age of cosmic rays would be independent of energy. This can be tested by high energy observations of the isotopic composition of Be.

Steitmatter, R. E.; Balasubrahmanyan, V. K.; Protheroe, R. J.; Ormes, J. F.

1984-01-01

184

Superdiffusion of Cosmic Rays: Implications for Cosmic Ray Acceleration  

NASA Astrophysics Data System (ADS)

Diffusion of cosmic rays (CRs) is the key process for understanding their propagation and acceleration. We employ the description of spatial separation of magnetic field lines in magnetohydrodynamic turbulence in Lazarian & Vishniac to quantify the divergence of the magnetic field on scales less than the injection scale of turbulence and show that this divergence induces superdiffusion of CR in the direction perpendicular to the mean magnetic field. The perpendicular displacement squared increases, not as the distance x along the magnetic field, which is the case for a regular diffusion, but as the x 3 for freely streaming CRs. The dependence changes to x 3/2 for the CRs propagating diffusively along the magnetic field. In the latter case, we show that it is important to distinguish the perpendicular displacement with respect to the mean field and to the local magnetic field. We consider how superdiffusion changes the acceleration of CRs in shocks and show how it decreases efficiency of the CRs acceleration in perpendicular shocks. We also demonstrate that in the case when the small-scale magnetic field is generated in the pre-shock region, an efficient acceleration can take place for the CRs streaming without collisions along the magnetic loops.

Lazarian, A.; Yan, Huirong

2014-03-01

185

Part II. Acceleration Mechanisms of Cosmic Rays  

Microsoft Academic Search

The mechanisms of accelerating charged particles in cosmic spaceare investigated systematically. As the cosmic rays are very common and important energy-carries in the universe, the acceleration procedures should be widely operative, including various scales of accelerating regions, various kinds of particles, various intensities of the field, and so on. These characters make it possible to introduce several hierarchy stages in

Satio Hayakawa; Jun Nishimura; Haruo Obayashi; Humitaka Sato

1964-01-01

186

Consistency of cosmic-ray source abudances with explosive nucleosynthesis  

NASA Technical Reports Server (NTRS)

A model was examined in which the cosmic ray abundances of elements from C to Fe are consistent with explosive nucleosynthesis. The observed abundance of cosmic rays near the earth, cosmic ray source abundance, and solar system abundance are discussed along with the ratios of cosmic ray sources to the solar system abundances.

Kozlovsky, B.; Ramaty, R.

1973-01-01

187

The Cosmic Ray Measurements Above 1 TeV  

E-print Network

The Cosmic Ray Measurements Above 1 TeV Shigeru Yoshida Institute for Cosmic Ray Research of cosmic rays with energies above 1 TeV (10 12 eV). Most of the measurements are consistent with our baseline picture of origins of the cosmic rays that the higher energy extragalactic component is starting

Yoshida, Shigeru

188

A Simplified Model for the Acceleration of Cosmic Ray Particles  

ERIC Educational Resources Information Center

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

Gron, Oyvind

2010-01-01

189

Cosmic ray antimatter and baryon symmetric cosmology  

SciTech Connect

The relative merits and difficlties of the primary and secondry origin hypotheses for the observed cosmic-ray antiprotons, including the new low-energy measurement of Buffington, et al are discussed. We conclude that the cosmic-ray antiproton data may be evidence for antimatter galaxies and baryon symmetric cosmology. The present bar P data are consistent with a primary extragalactic component having /p /equiv 1+/- 3.2/0.7x10 to the -4 independent of energy. We propose that the primary extragalactic cosmic ray antiprotons are most likely from active galaxies and that expected disintegration of bar alpha/alpha ban alpha/alpha. We further predict a value for ban alpha/alpha /equiv 10 to the -5, within range of future cosmic ray detectors.

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

1982-06-01

190

Cosmic ray antimatter and baryon symmetric cosmology  

NASA Technical Reports Server (NTRS)

The relative merits and difficulties of the primary and secondary origin hypotheses for the observed cosmic-ray antiprotons, including the new low-energy measurement of Buffington, et al. We conclude that the cosmic-ray antiproton data may be evidence for antimatter galaxies and baryon symmetric cosmology. The present bar P data are consistent with a primary extragalactic component having /p=/equiv 1+/- 3.2/0.7x10 = to the -4 independent of energy. We propose that the primary extragalactic cosmic ray antiprotons are most likely from active galaxies and that expected disintegration of bar alpha/alpha ban alpha/alpha. We further predict a value for ban alpha/alpha =/equiv 10 to the -5, within range of future cosmic ray detectors.

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

1982-01-01

191

Removal of Cosmic Ray-Induced Noise from Kepler Data  

NASA Astrophysics Data System (ADS)

NASA's Kepler Mission is designed to detect transiting exoplanets by measuring stellar brightness attenuation as small as 84 parts per million. Attaining the required photometric precision depends partly on the ability of ground-based data processing algorithms to mitigate the effects of significant noise sources. Among these is the charge released in the photometer's CCDs by cosmic rays and solar energetic particles (we loosely refer to all such particles as "cosmic rays", regardless of their origin), which continuously bombard the instrument with an estimated mean flux of of 5 cm-2 s-1. Cosmic ray strikes appear in pixel time series as a sequence of positive impulses affecting roughly one in five long cadence measurements (Kepler's primary data collection mode). The problem of separating cosmic ray-induced signal from other signal components is complicated both by the 30 min effective integration period of a long cadence measurement and by the fact that high-frequency stellar variations and image motion can also produce impulse-like features in pixel flux time series. We present an algorithm for detecting and removing the effects of cosmic rays on Kepler pixel time series. Given the pixels comprising a target star's aperture, each variance-normalized and lightly detrended time series is modeled as a combination of the effects of intrinsic stellar variability, image motion, and cosmic ray strikes. The cosmic ray signal component is modeled as a Poisson process in which the magnitude of each event is drawn from a known distribution, while stellar variability is modeled as the sum of an autoregressive process and a small set (possibly empty) of salient harmonic components. Both simulation tests and analysis of results from Kepler flight data demonstrate the algorithm's effectiveness. Kepler was selected as the 10th mission of the Discovery Program. Funding for this mission is provided by NASAs Science Mission Directorate.

Morris, Robert L.; Jenkins, J. M.; Twicken, J.

2012-10-01

192

28th International Cosmic Ray Conference 3851 A 2D stochastic simulation of galactic cosmic rays transport  

E-print Network

28th International Cosmic Ray Conference 3851 A 2D stochastic simulation of galactic cosmic rays, Russia. Abstract We present a new code to numerically simulate the transport of galactic cosmic rays Galactic cosmic rays suffer from modulation in the heliosphere. Basic modulation mechanisms are diffusion

Usoskin, Ilya G.

193

29th International Cosmic Ray Conference Pune (2005) 2, 465468 Real-Time Cosmic Ray Distributed (RECORD) database: A status  

E-print Network

29th International Cosmic Ray Conference Pune (2005) 2, 465­468 Real-Time Cosmic Ray Distributed of operation of the Real-Time Cosmic Ray Distributed (RECORD) database. This collaborative international and tested for more than a year. At present, the RECORD database contains 1-min data of cosmic ray intensity

Usoskin, Ilya G.

194

Calibration of a solid state nuclear track detector (SSNTD) with high detection threshold to search for rare events in cosmic rays  

E-print Network

We have investigated a commercially available polymer for its suitability as a solid state nuclear track detector (SSNTD). We identified that polymer to be polyethylene terephthalate (PET) and found that it has a higher detection threshold compared to many other widely used SSNTDs which makes this detector particularly suitable for rare event search in cosmic rays as it eliminates the dominant low Z background. Systematic studies were carried out to determine its charge response which is essential before any new material can be used as an SSNTD. In this paper we describe the charge response of PET to 129Xe, 78Kr and 49Ti ions from the REX-ISOLDE facility at CERN, present the calibration curve for PET and characterize it as a nuclear track detector.

S. Dey; D. Gupta; A. Maulik; Sibaji Raha; Swapan K. Saha; D. Syam; J. Pakarinen; D. Voulot; F. Wenander

2011-03-23

195

Longevity and Highest-Energy Cosmic Rays  

E-print Network

It is proposed that the highest energy $\\sim 10^{20}$eV cosmic ray primaries are protons, decay products of a long-lived progenitor which has propagated from typically $\\sim 100$Mpc. Such a scenario can occur in e.g. SU(15) grand unification and in some preon models, but is more generic; if true, these unusual cosmic rays provide a window into new physics.

Paul H. Frampton; Bettina Keszthelyi; Y. Jack Ng

1997-09-10

196

Apollo 17 lunar surface cosmic ray detector  

NASA Technical Reports Server (NTRS)

The objectives and selected data are presented for the Apollo 17 Lunar Surface Cosmic Ray Experiment (LSCRE) for the purpose of introducing an analysis of three of the separate detectors contained within in LSCRE package. The mica detector for measuring heavy solar wind, and the lexan stack and glass detectors for measuring energetic particles in space are discussed in terms of their deployment, exposure time, calibration, and data yield. Relevant articles on solar particles, interplanetary ions, and cosmic ray nuclei are also included.

Walker, R. M.

1974-01-01

197

Spallogenic Light Elements and Cosmic Ray Origin  

NASA Technical Reports Server (NTRS)

Most of the Galactic Li-6, all of the Be and the bulk of the B are cosmic ray produced. I will discuss the production mechanisms and detail a recently developed evolutionary code for Fe,O and these light elements. I will review the leading models for Li, Be and B origin and discuss their implications on cosmic ray origin. I will also show evidence for extragalactic production of Li-6.

Ramaty, Reuven

2000-01-01

198

Recent developments in cosmic ray physics  

NASA Astrophysics Data System (ADS)

The search for a theory of the origin of cosmic rays that may be considered as a standard, agreeable model is still ongoing. On one hand, much circumstantial evidence exists of the fact that supernovae in our Galaxy play a crucial role in producing the bulk of cosmic rays observed on Earth. On the other hand, important questions about their ability to accelerate particles up to the knee remain unanswered. The common interpretation of the knee as a feature coinciding with the maximum energy of the light component of cosmic rays and a transition to a gradually heavier mass composition is mainly based on KASCADE results. Some recent data appear to question this finding: YAC1 - Tibet Array and ARGO-YBJ find a flux reduction in the light component at ? 700 TeV, appreciably below the knee. Whether the maximum energy of light nuclei is as high as 3000 TeV or rather as low as a few hundred TeV has very important consequences on the supernova remnant paradigm for the origin of cosmic rays, as well on the crucial issue of the transition from Galactic to extragalactic cosmic rays. In such a complex phenomenological situation, it is important to have a clear picture of what is really known and what is not. Here I will discuss some solid and less solid aspects of the theory (or theories) for the origin of cosmic rays and the implications for future searches in this field.

Blasi, P.

2014-11-01

199

Reminiscences of cosmic ray research in Mexico  

NASA Astrophysics Data System (ADS)

Cosmic ray research in Mexico dates from the early 1930s with the work of the pioneering physicist, Manuel Sandoval Vallarta and his students from Mexico. Several experiments of international significance were carried out during that period in Mexico: they dealt with the geomagnetic latitude effect, the north-south and west-east asymmetry of cosmic ray intensity, and the sign of the charge of cosmic rays. The international cosmic ray community has met twice in Mexico for the International Cosmic Ray Conferences (ICRC): the fourth was held in Guanajuato in 1955, and the 30th took place in Mrida, in 2007. In addition, an international meeting on the Pierre Auger Collaboration was held in Morelia in 1999, and the International Workshop on Observing UHE Cosmic Rays took place in Metepec in 2000. A wide range of research topics has been developed, from low-energy Solar Energetic Particles (SEP) to the UHE. Instrumentation has evolved since the early 1950s, from a Simpson type neutron monitor installed in Mexico City (2300 m asl) to a solar neutron telescope and an EAS Cherenkov array, (within the framework of the Auger International Collaboration), both at present operating on Mt. Sierra La Negra in the state of Puebla (4580 m asl). Research collaboration has been undertaken with many countries; in particular, the long-term collaboration with Russian scientists has been very fruitful.

Prez-Peraza, Jorge

2009-11-01

200

COSMIC-RAY HELIUM HARDENING  

SciTech Connect

Recent observations by the CREAM and ATIC-2 experiments suggest that (1) the spectrum of cosmic-ray (CR) helium is harder than that of CR protons below the knee energy, 10{sup 15}eV, and (2) all CR spectra become hard at {approx}>10{sup 11}eV nucleon{sup -1}. We propose a new idea, that higher energy CRs are generated in a more helium-rich region, to explain the hardening without introducing different sources for CR helium. The helium-to-proton ratio at {approx}100 TeV exceeds the Big Bang abundance Y = 0.25 by several times, and the different spectrum is not reproduced within the diffusive shock acceleration theory. We argue that CRs are produced in a chemically enriched region, such as a superbubble, and the outward-decreasing abundance naturally leads to the hard spectrum of CR helium if CRs escape from the supernova remnant shock in an energy-dependent way. We provide a simple analytical spectrum that also fits well the hardening due to the decreasing Mach number in the hot superbubble with {approx}10{sup 6} K. Our model predicts hard and concave spectra for heavier CR elements.

Ohira, Yutaka; Ioka, Kunihito, E-mail: ohira@post.kek.jp [Theory Center, Institute of Particle and Nuclear Studies, KEK (High Energy Accelerator Research Organization), 1-1 Oho, Tsukuba 305-0801 (Japan)

2011-03-01

201

Cosmic rays at ultra high energies (Neutrinos!)  

NASA Astrophysics Data System (ADS)

Resonant photo-pion production with the cosmic microwave background predicts a suppression of extragalactic protons above the famous Greisen Zatsepin Kuzmin cutoff at about EGZK ? 5 1010 GeV. Current cosmic ray data measured by the AGASA and HiRes Collaborations do not unambiguously confirm the GZK cutoff and leave a window for speculations about the origin and chemical composition of the highest energy cosmic rays. In this work we analyze the possibility of strongly interacting neutrino primaries and derive model-independent quantitative requirements on the neutrino nucleon inelastic cross section for a viable explanation of the cosmic ray data. Search results on weakly interacting cosmic particles from the AGASA and RICE experiments are taken into account simultaneously. Using a flexible parameterization of the inelastic neutrino nucleon cross section we find that a combined fit of the data does not favor the Standard Model neutrino nucleon inelastic cross section, but requires, at 90% confidence level, a steep increase within one energy decade around EGZK by four orders of magnitude. We illustrate such an enhancement within some extensions of the Standard Model. The impact of new cosmic ray data or cosmic neutrino search results on this scenario, notably from the Pierre Auger Observatory soon, can be immediately evaluated within our approach.

Ahlers, Markus; Ringwald, Andreas; Tu, Huitzu

2006-01-01

202

Contributions to the 19th International Cosmic Ray Conference  

NASA Technical Reports Server (NTRS)

Various aspects of cosmic radiation, its measurements and their patterns are presented. Measurement techniques and variations in solar cosmic ray patterns and calculations of elemental abundances are reviewed.

1985-01-01

203

The HAWC Gamma-Ray Observatory: Observations of Cosmic Rays  

E-print Network

We describe measurements of GeV and TeV cosmic rays with the High-Altitude Water Cherenkov Gamma-Ray Observatory, or HAWC. The measurements include the observation of the shadow of the moon; the observation of small-scale and large-scale angular clustering of the TeV cosmic rays; the prospects for measurement of transient solar events with HAWC; and the observation of Forbush decreases with the HAWC engineering array and HAWC-30.

Abeysekara, A U; Alvarez, C; lvarez, J D; Arceo, R; Arteaga-Velzquez, J C; Solares, H A Ayala; Barber, A S; Baughman, B M; Bautista-Elivar, N; Belmont, E; BenZvi, S Y; Berley, D; Rosales, M Bonilla; Braun, J; Caballero-Lopez, R A; Caballero-Mora, K S; Carramiana, A; Castillo, M; Cotti, U; Cotzomi, J; de la Fuente, E; De Len, C; DeYoung, T; Hernandez, R Diaz; Daz-Vlez, J C; Dingus, B L; DuVernois, M A; Ellsworth, R W; Fernandez, A; Fiorino, D W; Fraija, N; Galindo, A; Garfias, F; Gonzlez, L X; Gonzlez, M M; Goodman, J A; Grabski, V; Gussert, M; Hampel-Arias, Z; Hui, C M; Hntemeyer, P; Imran, A; Iriarte, A; Karn, P; Kieda, D; Kunde, G J; Lara, A; Lauer, R J; Lee, W H; Lennarz, D; Vargas, H Len; Linares, E C; Linnemann, J T; Longo, M; Luna-GarcIa, R; Marinelli, A; Martinez, H; Martinez, O; Martnez-Castro, J; Matthews, J A J; Miranda-Romagnoli, P; Moreno, E; Mostaf, M; Nava, J; Nellen, L; Newbold, M; Noriega-Papaqui, R; Oceguera-Becerra, T; Patricelli, B; Pelayo, R; Prez-Prez, E G; Pretz, J; Rivire, C; Rosa-Gonzlez, D; Salazar, H; Salesa, F; Sanchez, F E; Sandoval, A; Santos, E; Schneider, M; Silich, S; Sinnis, G; Smith, A J; Sparks, K; Springer, R W; Taboada, I; Toale, P A; Tollefson, K; Torres, I; Ukwatta, T N; Villaseor, L; Weisgarber, T; Westerhoff, S; Wisher, I G; Wood, J; Yodh, G B; Younk, P W; Zaborov, D; Zepeda, A; Zhou, H

2013-01-01

204

Cosmic Rays 8.1 Composition and energy distribution  

E-print Network

Chapter 8 Cosmic Rays 8.1 Composition and energy distribution Cosmic rays can be broadly defined as the massive particles, photons ( rays, X-rays, ultra- violet and infrared radiation, ...), neutrinos, and exotics (WIMPS, axions,...) striking the earth. The primary cosmic rays are those entering the upper

Washington at Seattle, University of - Department of Physics, Electroweak Interaction Research Group

205

HIGH-ENERGY X-RAY DETECTION OF G359.890.08 (SGR AE): MAGNETIC FLUX TUBE EMISSION POWERED BY COSMIC RAYS?  

E-print Network

We report the first detection of high-energy X-ray (E > 10 keV) emission from the Galactic center non-thermal filament G359.890.08 (Sgr AE) using data acquired with the Nuclear Spectroscopic Telescope Array (NuSTAR). The ...

Zhang, Shuo

206

THE COMPOSITION OF ULTRA HIGH ENERGY COSMIC RAYS THROUGH HYBRID  

E-print Network

for detecting cosmic rays. This analysis combines both ground array and fluorescence data in a hybrid analysis iron. However, above 1019.3 eV, the statistical power is limited and the data is compatible either proton or iron MCs. The shapes of the Xmax distributions independent of their means are compared, showing

207

Measurement of the energy of horizontal cosmic ray muons  

NASA Astrophysics Data System (ADS)

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.

Gettert, Michael

1993-03-01

208

29th International Cosmic Ray Conference Pune (2005) 2, 247250 Long-Term Modulation of the Cosmic Ray Fluctuation Spectrum  

E-print Network

29th International Cosmic Ray Conference Pune (2005) 2, 247­250 Long-Term Modulation of the Cosmic recently studied (Starodubtsev et al., 2004) cosmic ray fluctuations in the frequency range that the level of cosmic ray fluctuations is subject to long-term modulation in phase with the sunspot cycle

Usoskin, Ilya G.

209

Galactic modulation of extragalactic cosmic rays: Possible origin of the knee in the cosmic ray spectrum  

E-print Network

The existence of the spectral break around $\\sim 3 \\times 10^{15}$ eV in the cosmic ray spectrum (referred to as the `knee') is one of the biggest questions in cosmic ray astrophysics. At the same time, the origin of cosmic rays above the knee energies (between 10$^{15}$ and 10$^{18}$ eV) is also still unsettled. In this paper, we investigate how the hypothetical extragalactic CRs after modulated by the galactic wind contribute to the knee in the CR spectrum. We numerically calculate the modulated energy spectrum of the hypothetical cosmic rays coming into the galaxy from just outside of the ``galactic sphere'' where the galactic wind terminates. We show that the observed knee structure is reproduced well by a superposition of the modulated component and the galactic cosmic rays originating in supernova remnants.

Hiroshi Muraishi; Shohei Yanagita; Tatsuo Yoshida

2005-02-07

210

Positron fraction in cosmic rays and models of cosmic-ray propagation  

SciTech Connect

The positron fraction observed by PAMELA and other experiments up to {approx}100 GeV is analyzed in terms of models of cosmic-ray propagation. It is shown that generically we expect the positron fraction to reach {approx}0.6 at energies of several TeV, and its energy dependence bears an intimate but subtle connection with that of the boron to carbon ratio in cosmic rays. The observed positron fraction can be fit in a model that assumes a significant fraction of the boron below {approx}10 GeV is generated through spallation of cosmic-ray nuclei in a cocoonlike region surrounding the sources, and the positrons of energy higher than a few GeV are almost exclusively generated through cosmic-ray interactions in the general interstellar medium. Such a model is consistent with the bounds on cosmic-ray anisotropies and other observations.

Cowsik, R.; Burch, B. [Physics Department and McDonnell Center for the Space Sciences, Washington University, St. Louis, Missouri 63130 (United States)

2010-07-15

211

THE INTERACTION OF COSMIC RAYS WITH DIFFUSE CLOUDS  

SciTech Connect

We study the change in cosmic-ray pressure, the change in cosmic-ray density, and the level of cosmic-ray-induced heating via Alfven-wave damping when cosmic rays move from a hot ionized plasma to a cool cloud embedded in that plasma. The general analysis method outlined here can apply to diffuse clouds in either the ionized interstellar medium or in galactic winds. We introduce a general-purpose model of cosmic-ray diffusion building upon the hydrodynamic approximation for cosmic rays (from McKenzie and Voelk and Breitschwerdt and collaborators). Our improved method self-consistently derives the cosmic-ray flux and diffusivity under the assumption that the streaming instability is the dominant mechanism for setting the cosmic-ray flux and diffusion. We find that, as expected, cosmic rays do not couple to gas within cool clouds (cosmic rays exert no forces inside of cool clouds), that the cosmic-ray density does not increase within clouds (it may decrease slightly in general, and decrease by an order of magnitude in some cases), and that cosmic-ray heating (via Alfven-wave damping and not collisional effects as for {approx}10 MeV cosmic rays) is only important under the conditions of relatively strong (10 {mu}G) magnetic fields or high cosmic-ray pressure ({approx}10{sup -11} erg cm{sup -3}).

Everett, John E.; Zweibel, Ellen G., E-mail: everett@physics.wisc.edu [Department of Astronomy, University of Wisconsin-Madison, Madison, WI 53706 (United States)

2011-10-01

212

High Energy Cosmic Rays and Neutrinos from Newborn Pulsars  

NASA Astrophysics Data System (ADS)

Newborn pulsars offer favorable sites for cosmic ray acceleration and interaction. Particles could be striped off the star surface and accelerated in the pulsar wind up to PeV-100 EeV energies, depending on the pulsar's birth period and magnetic field strength. Once accelerated, the cosmic rays interact with the surrounding supernova ejecta until they escape the source. By assuming a normal distribution of pulsar birth periods centered at 300,ms, we find the combined contribution of extragalactic pulsars produce ultrahigh energy cosmic rays that agree with both the observed energy spectrum and composition trend reported by the Auger Observatory. Meanwhile, we point out their Galactic counterparts naturally give rise to a cosmic ray flux peaked at very high energies (VHE, between 10^16 and 10^18 ,eV), which can bridge the gap between predictions of cosmic rays produced by supernova remnants and the observed spectrum and composition just below the ankle. Young pulsars in the universe would also contribute to a diffuse neutrino background due to the photomeson interactions, whose detectability and typical neutrino energy are discussed. Lastly, we predict a neutrino emission level for the future birth of a nearby pulsar.

Fang, Ke; Kotera, Kumiko; Olinto, Angela

2013-04-01

213

Lecture notes on high energy cosmic rays  

E-print Network

I give a concise introduction into high energy cosmic ray physics, including also few related aspects of high energy gamma-ray and neutrino astrophysics. The main emphasis is placed on astrophysical questions, and the level of the presentation is kept basic.

M. Kachelriess

2008-01-29

214

Integral Neutron Multiplicity Measurements from Cosmic Ray Interactions in Lead  

NASA Astrophysics Data System (ADS)

Sixty element 3He neutron multiplicity detector systems were designed, constructed and tested for use in cosmic ray experiments with a 30-cm cube lead target. A series of measurements were performed for the cosmic ray configuration at ground level (3 meters water equivalent, mwe), in the St. Petersburg metro tunnel (185 mwe), and in the Pyhasalmi mine in Finland (583 and 1185 mwe). Anomalous coincidence events with charged cosmic ray particles at sea level produced events with 100-120 neutrons due possibly to the total disintegration of the Pb nucleus. These events were also detected at 185 mwe, but the particles causing such disintegration are currently unidentified. We present examples of preliminary data from the various measurements and discuss future plans for underground experiments including possible searches for Weakly Interacting Massive Particles (WIMP, dark matter).

Ward, Thomas E.; Rimsky-Korsakov, Alexander A.; Kudryashev, Nikolai A.; Beller, Denis E.

2006-07-01

215

Integral Neutron Multiplicity Measurements from Cosmic Ray Interactions in Lead  

SciTech Connect

Sixty element 3He neutron multiplicity detector systems were designed, constructed and tested for use in cosmic ray experiments with a 30-cm cube lead target. A series of measurements were performed for the cosmic ray configuration at ground level (3 meters water equivalent, mwe), in the St. Petersburg metro tunnel (185 mwe), and in the Pyhasalmi mine in Finland (583 and 1185 mwe). Anomalous coincidence events with charged cosmic ray particles at sea level produced events with 100-120 neutrons due possibly to the total disintegration of the Pb nucleus. These events were also detected at 185 mwe, but the particles causing such disintegration are currently unidentified. We present examples of preliminary data from the various measurements and discuss future plans for underground experiments including possible searches for Weakly Interacting Massive Particles (WIMP, dark matter)

Ward, Thomas E. [Techsource Inc., 1418 Luisa St., Santa Fe. New Mexico 87505 (United States); Rimsky-Korsakov, Alexander A.; Kudryashev, Nikolai A. [V. G. Khlopin Radium Institute, 194021, 2-nd Murinsky pr. 28, St. Petersburg (Russian Federation); Beller, Denis E. [University of Nevada, Las Vegas, 4505 Maryland Parkway Box 454027, Las Vegas, NV 89154-4027 (United States)

2006-07-11

216

Primary cosmic ray particles with z 35 (VVH particles). [very heavy particle detection by high altitude balloons  

NASA Technical Reports Server (NTRS)

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.

Blanford, G. E., Jr.; Friedlander, M. W.; Hoppe, M.; Klarmann, J.; Walker, R. M.; Wefel, J. P.

1972-01-01

217

Cosmic rays and tests of fundamental principles  

E-print Network

It is now widely acknowledged that cosmic rays experiments can test possible new physics directly generated at the Planck scale or at some other fundamental scale. By studying particle properties at energies far beyond the reach of any man-made accelerator, they can yield unique checks of basic principles. A well-known example is provided by possible tests of special relativity at the highest cosmic-ray energies. But other essential ingredients of standard theories can in principle be tested: quantum mechanics, uncertainty principle, energy and momentum conservation, effective space-time dimensions, hamiltonian and lagrangian formalisms, postulates of cosmology, vacuum dynamics and particle propagation, quark and gluon confinement, elementariness of particles... Standard particle physics or string-like patterns may have a composite origin able to manifest itself through specific cosmic-ray signatures. Ultra-high energy cosmic rays, but also cosmic rays at lower energies, are probes of both "conventional" and new Physics. Status, prospects, new ideas, and open questions in the field are discussed. The Post Scriptum shows that several basic features of modern cosmology naturally appear in a SU(2) spinorial description of space-time without any need for matter, relativity or standard gravitation. New possible effects related to the spinorial space-time structure can also be foreseen. Similarly, the existence of spin-1/2 particles can be naturally related to physics beyond Planck scale and to a possible pre-Big Bang era.

Luis Gonzalez-Mestres

2010-11-22

218

Magnetized supernova remnants with cosmic rays  

NASA Technical Reports Server (NTRS)

The effects of interstellar magnetic fields and cosmic rays on the dynamics of an SNR expanding into a warm H I gas are examined. As long as the shock wave driven by the SN explosion propagates faster than 110 km/s, the vicinity of the shock front is fully ionized, and cosmic rays are well coupled to the thermal fluid. They are first accelerated at the adiabatic front, and further compressed in the postshock cooling zone. When the shock velocity drops below 110 km/s, ion-neutral collisions in the vicinity of the shock dissipate the waves which couple cosmic rays to the thermal gas, and impede cosmic-ray acceleration. It is found that magnetic and cosmic-ray pressures together dominate over thermal pressure away from the magnetic poles. As a result, most of the shell becomes considerably thicker, and the shock wave propagates somewhat faster than in the nonmagnetic case. At late times, the transverse mass motions which take place from the poles to the equator create H I holes at the polar caps. This theory leads to a simple interpretation of the 'barrel-shaped' distribution of radio emission observed in some SNRs.

Ferriere, Katia M.; Zweibel, Ellen G.

1991-01-01

219

High Energy Cosmic Electrons: Messengers from Nearby Cosmic Ray Sources or Dark Matter?  

NASA Technical Reports Server (NTRS)

This slide presentation reviews the recent discoveries by the Large Area Telescope (LAT) and the Gamma-ray Burst Monitor (GBM) on board the Fermi Gamma-Ray Telescope in reference to high energy cosmic electrons, and whether their source is cosmic rays or dark matter. Specific interest is devoted to Cosmic Ray electrons anisotropy,

Moiseev, Alexander

2011-01-01

220

A Tale of Cosmic Rays Narrated in ? Rays by Fermi  

NASA Astrophysics Data System (ADS)

Because cosmic rays are charged particles scrambled by magnetic fields, combining direct measurements with other observations is crucial to understanding their origin and propagation. As energetic particles traverse matter and electromagnetic fields, they leave marks in the form of neutral interaction products. Among those, ? rays trace interactions of nuclei that inelastically collide with interstellar gas, as well as of leptons that undergo Bremsstrahlung and inverse-Compton scattering. Data collected by the Fermi large area telescope (LAT) are therefore telling us the story of cosmic rays along their journey from sources through their home galaxies. Supernova remnants emerge as a notable ?-ray source population, and older remnants interacting with interstellar matter finally show strong evidence of the presence of accelerated nuclei. Yet the maximum energy attained by shock accelerators is poorly constrained by observations. Cygnus X, a massive star-forming region established by the LAT as housing cosmic-ray sources, provides a test case to study the impact of wind-driven turbulence on the early propagation. Interstellar emission resulting from the large-scale propagation of cosmic rays in the Milky Way is revealed in unprecedented detail that challenges some of the simple assumptions used for the modeling. Moreover, the cosmic-ray induced ?-ray luminosities of galaxies-scale quasi-linearly with their massive-star formation rates: the overall normalization of that relation below the calorimetric limit suggests that for most systems, a substantial fraction of energy in cosmic rays escapes into the intergalactic medium. The nuclear production models and the distribution of target gas and radiation fields, not determined precisely enough yet, are key to exploiting the full potential of ?-ray data. Nevertheless, data being collected by Fermi and complementary multiwavelength/multimessenger observations are bringing us ever closer to solving the cosmic-ray mystery.

Tibaldo, Luigi

2014-10-01

221

Detectors of Cosmic Rays, Gamma Rays, and Neutrinos  

SciTech Connect

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

Altamirano, A. [Departamento de Fisica, Informatica y Matematicas, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia (Peru); Centro de Tecnologias de Informacion y Comunicaciones (CTIC), Universidad Nacional de Ingenieria, Lima (Peru); Navarra, G. [Dipartimento di Fisica Generale dell'Universita' and INFN, Torino (Italy)

2009-04-30

222

Review of the Second School on Cosmic Rays and Astrophysics  

NASA Astrophysics Data System (ADS)

The Second School on Cosmic Rays and Astrophysics was held in Puebla, Mexico, on August 30 to September 8, 2006. It included subjects like experimental techniques, primary spectrum and composition of cosmic rays, high-energy interactions, gamma ray astronomy, neutrino astrophysics, cosmic ray detectors, etc. I present a very short review of some of the lectures given there.

Martnez, Humberto

2009-04-01

223

Search for correlations of GRB and cosmic rays  

NASA Astrophysics Data System (ADS)

It is possible that violent processes resulting in Gamma Ray Bursts produce also high energy photons and cosmic rays. The possible correlations of very short GRB with, e.g., CMB, cosmic rays is briefly discussed. We have also begun preparation of the experiment correlating in real time data from Maze cosmic ray detector and Pi of the Sky robotic telescope.

J?drzejczak, K.; Kasztelan, M.; Mankiewicz, L.; Molak, M.; Nawrocki, K.; Piotrowski, L. W.; Soko?owski, M.; Szabelska, B.; Szabelski, J.; Wibig, T.; Wolfendale, A. W.; Wrochna, G.

2007-06-01

224

Underground cosmic-ray experiment EMMA  

NASA Astrophysics Data System (ADS)

A new cosmic-ray experiment is under construction in the Pyhsalmi mine, Finland. It aims to study the chemical composition of cosmic rays at and above the knee region. The array, called EMMA, will cover approximately 150 m 2 of detector area at the depth of 85 metres ( 240 mwe). It is capable of measuring the multiplicity and the lateral distribution of underground muons, and the arrival direction of the air shower. The full-size array is expected to be ready by the end of 2007. A partial-size array (one third of the full size) is planned to record data already at the first quarter of 2007. The array is also expected to be capable of measuring such high-multiplicity muon bundles as was observed at the cosmic-ray experiments at the LEP detectors.

Enqvist, T.; Joutsenvaara, J.; Jmsn, T.; Kernen, P.; Kuusiniemi, P.; Lehtola, M.; Mattila, A.; Narkilahti, J.; Peltoniemi, J.; Pennanen, A.; Rih, T.; Sarkamo, J.; Shen, C.; Trzaska, W.; Usoskin, I.; Vaittinen, M.; Zhang, Z.

2007-03-01

225

Does electromagnetic radiation accelerate galactic cosmic rays  

NASA Technical Reports Server (NTRS)

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.

Eichler, D.

1977-01-01

226

Bruno Rossi: Cosmic Ray Research 1929 - 1953  

NASA Astrophysics Data System (ADS)

Bruno Rossi, a fresh PhD from the University of Bologna, arrived in Florence in 1928. He was appointed assistant to Antonio Garbasso, professor of experimental physics. Garbosso at that time was Mayor of Florence. His days of physics were over which gave the young Rossi a freedom to follow any line of research. After some agonizing he came upon research in cosmic rays following the discovery that a large part of the cosmic rays were charged particles. Thus began a long period of creative research. Rossi had all the talents needed, a powerful intellect and the natural ability to construct apparatus that gave clear results for his experiments. I will give some examples of his many discoveries concerning the nature of cosmic rays.

Cronin, Jim

2012-03-01

227

Cosmic ray transport in MHD turbulence  

E-print Network

Recent advances in understanding of magnetohydrodynamic (MHD) turbulence call for revisions in the picture of cosmic ray transport. In this paper we use recently obtained scaling laws for MHD modes to obtain the scattering frequency for cosmic rays. We account for the turbulence cutoff arising from both collisional and collisionless damping. We obtain the scattering rate and show that fast modes provide the dominant contribution to cosmic ray scattering for the typical interstellar conditions in spite of the fact that fast modes are subjected to damping. We determine how the efficiency of the scattering depends on the characteristics of ionized media, e.g. plasma $\\beta$. We show that streaming instability is suppressed by the ambient MHD turbulence.

Huirong Yan; A. Lazarian

2005-05-28

228

Cosmic ray albedo gamma rays from the quiet sun  

NASA Technical Reports Server (NTRS)

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).

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

1992-01-01

229

Cosmic-ray acceleration in supernova shocks  

E-print Network

Galactic cosmic rays are widely believed to be accelerated in expanding shock waves initiated by supernova explosions. The theory of diffusive shock acceleration of cosmic rays is now well established, but two fundamental questions remain partly unanswered: what is the acceleration efficiency, i.e. the fraction of the total supernova energy converted to cosmic-ray energy, and what is the maximum kinetic energy achieved by particles accelerated in supernova explosions? Recent observations of supernova remnants, in X-rays with the Chandra and XMM-Newton satellites and in very-high-energy gamma rays with several ground-based atmospheric Cerenkov telescopes, have provided new pieces of information concerning these two questions. After a review of these observations and their current interpretations, I show that complementary information on the diffusive shock acceleration process can be obtained by studying the radio emission from extragalactic supernovae. As an illustration, a nonlinear model of diffusive shock acceleration is applied to the radio light curves of the supernova SN 1993J, which exploded in the nearby galaxy M81. The results of the model suggest that most of the Galactic cosmic rays may be accelerated during the early phase of interaction between the supernova ejecta and the wind lost from the progenitor star.

Vincent Tatischeff

2008-04-07

230

Can Cosmic Rays Heat the Intergalactic Medium?  

E-print Network

Supernova explosions in the early star forming galaxies will accelerate cosmic rays (CRs). CRs are typically confined in the collapsed objects for a short period before escaping into the intergalactic medium (IGM). Galactic outflows can facilitate this escape by advecting CRs into the IGM. An outflow that results in a termination shock can also generate more CRs. We show that the CR protons from the above processes can significantly affect the thermal history of the IGM. Within plausible range of parameters, cosmic ray heating can compensate for adiabatic cooling and explain the measured IGM temperature at redshifts z between 2 to 4, even with early reionization.

Saumyadip Samui; Kandaswamy Subramanian; Raghunathan Srianand

2005-05-30

231

Can Cosmic Rays Heat the Intergalactic Medium?  

E-print Network

Supernova explosions in the early star forming galaxies will accelerate cosmic rays (CRs). CRs are typically confined in the collapsed objects for a short period before escaping into the intergalactic medium (IGM). Galactic outflows can facilitate this escape by advecting CRs into the IGM. An outflow that results in a termination shock can also generate more CRs. We show that the CR protons from the above processes can significantly affect the thermal history of the IGM. Within plausible range of parameters, cosmic ray heating can compensate for adiabatic cooling and explain the measured IGM temperature at redshifts z between 2 to 4, even with early reionization.

Samui, S; Srianand, R; Samui, Saumyadip; Subramanian, Kandaswamy; Srianand, Raghunathan

2005-01-01

232

Threshold meson production and cosmic ray transport  

E-print Network

An interesting accident of nature is that the peak of the cosmic ray spectrum, for both protons and heavier nuclei, occurs near the pion production threshold. The Boltzmann transport equation contains a term which is the cosmic ray flux multiplied by the cross section. Therefore when considering pion and kaon production from proton-proton reactions, small cross sections at low energy can be as important as larger cross sections at higher energy. This is also true for subthreshold kaon production in nuclear collisions, but not for subthreshold pion production.

John W. Norbury; Lawrence W. Townsend; Ryan B. Norman

2006-12-11

233

Aspects of cosmic-ray positron astrophysics  

Microsoft Academic Search

AbstractCosmic-ray e,) data indicate pair produc- tion in the pulsar magnetosphere,as one of the most,promising sources of positrons above 10 GeV . On the other hand, braking index observations suggest that energy,loss mechanisms,different from electromagnetic occur at the pulsars. In particular, we focused,on the role of debris,disks from,Supernova,fallback material. We find that present cosmic-ray positron observations remain,consistent with a pulsar,origin

Catia Grimani

234

30th International Cosmic Ray Conference Hybrid Performance of the Pierre Auger Observatory  

E-print Network

calculable aper- ture. The FD provides the conversion between S(1000) and the cosmic ray primary energy, #12- ditional FD direction fitting method with the arrival time of the shower at the ground mea- sured design, in which ultra high energy cosmic rays are detected simultaneously by fluorescence telescopes

235

The Fly's Eye Extremely High Energy Cosmic Ray Spectrum D.J. Bird,1  

E-print Network

The Fly's Eye Extremely High Energy Cosmic Ray Spectrum D.J. Bird,1 S.C. Corbato,3 H.Y. Dai,3 B present our latest results on the cosmic ray energy spectrum above 1017 eV observed by Fly's Eye. Tracks detected by both eyes can be well reconstructed and therefore have very good energy resolution

236

Cosmic-Ray Source Composition Determined from ACE  

NASA Technical Reports Server (NTRS)

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.

Wiedenbeck, M.

2000-01-01

237

The Heliosphere and Galactic Cosmic Rays - Duration: 0:39.  

NASA Video Gallery

The heliosphere deflects galactic cosmic rays from entering the system. Galactic cosmic rays are a very high energy form of particle radiation that are extremely difficult to shield against and are...

238

Pulsars, supernovae, and ultrahigh energy cosmic rays  

NASA Astrophysics Data System (ADS)

The acceleration of ultrahigh energy nuclei in fast spinning newborn pulsars can explain the observed spectrum of ultrahigh energy cosmic rays and the trend towards heavier nuclei for energies above 10^{19} eV as indicated by air shower studies reported by the Auger Observatory. By assuming a normal distribution of pulsar birth periods centered at 300 ms, we show that the contribution of extragalactic pulsar births to the ultrahigh energy cosmic ray spectrum naturally gives rise to a contribution to very high energy cosmic rays (VHECRs, between 10^{16} and 10^{18} eV) by Galactic pulsar births. The required injected composition to fit the observed spectrum depends on the absolute energy scale, differing considerably between the energy scale used by Auger and that used by the Telescope Array. Depending on the composition of the cosmic rays that escape the supernova remnant and the diffusion behavior of VHECRs in the Galaxy, the contribution of Galactic pulsar births can also bridge the gap between predictions for cosmic ray acceleration in supernova remnants and the observed spectrum below the ankle. Fast spinning newborn pulsars that could produce UHECRs would be born in supernovae that could present interesting specific radiative features, due to the interaction of the pulsar wind with the surrounding ejecta. The resulting supernova lightcurves could present a high luminosity plateau over a few years, and a bright X-ray and gamma-ray peak around one or two years after the onset of the explosion. If such signatures were observed, they could have important implications both for UHECR astrophysics and for the understanding of core-collapse supernovae.

Kotera, K.; Fang, K.; Olinto, A. V.; Phinney, E. S.

2012-12-01

239

Propagation of Cosmic Rays and Diffuse Galactic Gamma Rays  

NASA Technical Reports Server (NTRS)

This paper presents an introduction to the astrophysics of cosmic rays and diffuse gamma-rays and discusses some of the puzzles that have emerged recently due to more precise data and improved propagation models: the excesses in Galactic diffuse gamma-ray emission, secondary antiprotons and positrons, and the flatter than expected gradient of cosmic rays in the Galaxy. These also involve the dark matter, a challenge to modern physics, through its indirect searches in cosmic rays. Though the final solutions are yet to be found, I discuss some ideas and results obtained mostly with the numerical propagation model GALPROP. A fleet of spacecraft and balloon experiments targeting these specific issues is set to lift off in a few years, imparting a feeling of optimism that a new era of exciting discoveries is just around the corner. A complete and comprehensive discussion of all the recent results is not attempted here due to the space limitations.

Moskalenko, Igor V.

2004-01-01

240

Relic neutrino masses and the highest energy cosmic rays  

NASA Astrophysics Data System (ADS)

We consider the possibility that a large fraction of the ultrahigh energy cosmic rays are decay products of Z bosons which were produced in the scattering of ultrahigh energy cosmic neutrinos on cosmological relic neutrinos. We compare the observed ultrahigh energy cosmic ray spectrum with the one predicted in the above Z-burst scenario and determine the required mass of the heaviest relic neutrino as well as the necessary ultrahigh energy cosmic neutrino flux via a maximum likelihood analysis. We show that the value of the neutrino mass obtained in this way is fairly robust against variations in presently unknown quantities, like the amount of neutrino clustering, the universal radio background, and the extragalactic magnetic field, within their anticipated uncertainties. Much stronger systematics arises from different possible assumptions about the diffuse background of ordinary cosmic rays from unresolved astrophysical sources. In the most plausible case that these ordinary cosmic rays are protons of extragalactic origin, one is lead to a required neutrino mass in the range 0.08 eV leq mnu leq 1.3 eV at the 68 % confidence level. This range narrows down considerably if a particular universal radio background is assumed, e.g. to 0.08 eV leq mnu leq 0.40 eV for a large one. The required flux of ultrahigh energy cosmic neutrinos near the resonant energy should be detected in the near future by AMANDA, RICE, and the Pierre Auger Observatory, otherwise the Z-burst scenario will be ruled out.

Fodor, Zoltan; Katz, Sandor D.; Ringwald, Andreas

2002-06-01

241

Cosmic strings and ultra-high energy cosmic rays  

NASA Technical Reports Server (NTRS)

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.

Bhattacharjee, Pijushpani

1989-01-01

242

Cosmic Rays for Heliospheric Space Weather Storm Prediction  

NASA Astrophysics Data System (ADS)

The classical imaging of CME's by solar UV light is successfully applied on many satellites like for instance on SOHO, STEREO A and B or SDO. CME detection via UV light from ground based telescopes can't be carried out, because of the absorption of UV light in the Earth atmosphere. However CME detection is done on ground by means of cosmic ray muon telescopes in the Global Muon Detection Network (GMDN). Therefore the astrophysics and solar physics for GMDN are summarized in chapter 1. GMDN data and results are described in chapter 2. A space situational awareness (SSA) satellite, which has also the purpose of CME imaging by means of a telescope for cosmic rays are sketched in chapter 3.

Jansen, Frank; Behrens, Jrg

2011-06-01

243

astro-ph/941006720Oct1994 Detection of a Cosmic Ray with Measured Energy Well Beyond the  

E-print Network

attenuated at energies above 100 EeV (Stecker, 1968; Hill & Schramm, 1985; Yoshida & Teshima, 1993). For protons above 300 EeV, the attenuation length is less than 30 Mpc (Stecker, 1968). Nuclei and gamma rays

244

Solar influences on cosmic rays and cloud formation: A reassessment  

E-print Network

Solar influences on cosmic rays and cloud formation: A reassessment Bomin Sun1 and Raymond S 2002. [1] Svensmark and Friis-Christensen [1997] proposed a ``cosmic ray-cloud cover'' hypothesis that cosmic ray flux, modulated by solar activity, may modify global cloud cover and thus global surface

Bradley, Raymond S.

245

Studies of cosmic rays with the anticoincidence system  

E-print Network

Studies of cosmic rays with the anticoincidence system of the PAMELA satellite experiment SILVIO ORSI Doctoral Thesis Stockholm, Sweden 2007 #12;#12;Doctoral Thesis Studies of cosmic rays is the study of the antimatter component of cosmic rays over a wide range of energies (¯p: 80 MeV­190 GeV, e

Haviland, David

246

Cosmic Rays and Other Nonsense in Astronom ical CCD Imagers  

E-print Network

Cosmic Rays and Other Nonsense in Astronom­ ical CCD Imagers Don Groom Lawrence Berkeley National Laboratory Abstract: Cosmic­ray muons make recognizable straight tracks in the new­generation CCD and shielding. The cosmic­ray muon rate is irreducible. Our conclusions are supported by tests at the Lawrence

247

Testing fundamental principles with high-energy cosmic rays  

E-print Network

Testing fundamental principles with high-energy cosmic rays Luis Gonzalez-Mestres LAPP, Université_sci@yahoo.fr It is not yet clear [1] whether the observed flux suppression for ultra-high energy cosmic rays (UHECR to violations of standard special relativity modifying cosmic- ray propagation or acceleration at very high

248

Underground cosmic-ray experiment EMMA T. Enqvista  

E-print Network

Underground cosmic-ray experiment EMMA T. Enqvista , J. Joutsenvaaraa , T. J¨ams´enb , P. Ker A new cosmic-ray experiment is under construction in the Pyh¨asalmi mine, Finland. It aims to study the chem- ical composition of cosmic rays at and above the knee region. The array, called EMMA, will cover

Usoskin, Ilya G.

249

Anisotropy of Arrival Directions of Ultrahigh Energy Cosmic Rays  

E-print Network

Anisotropy of Arrival Directions of Ultrahigh Energy Cosmic Rays Chad Barrett Finley Submitted;ABSTRACT Anisotropy of Arrival Directions of Ultrahigh Energy Cosmic Rays Chad Barrett Finley This thesis investigates the origins of ultrahigh energy cosmic rays by searching for evidence of small-scale anisotropy

250

Cosmic Ray Pitch Angle Scattering Through 90 o  

E-print Network

Cosmic Ray Pitch Angle Scattering Through 90 o G.M. Felice 1 and R.M. Kulsrud 2 Princeton Plasma #12; -- 2 -- ABSTRACT We study the problem of cosmic ray di#usion in the galactic disk with particu in momentum space by wave­particle mirror interaction (here v # is the cosmic ray velocity parallel

251

LINK BETWEEN COSMIC RAYS AND CLOUDS ON DIFFERENT TIME SCALES  

E-print Network

LINK BETWEEN COSMIC RAYS AND CLOUDS ON DIFFERENT TIME SCALES ILYA G. USOSKIN and GENNADY A is related to a link between the cosmic ray flux and cloudiness. Here we review evidences relating terrestrial climate variability to changes of cosmic ray flux in the Earth's vicinity on different time scales

Usoskin, Ilya G.

252

Early Cosmic Ray Research In France Olivier Ravela  

E-print Network

Early Cosmic Ray Research In France Olivier Ravela a SUBATECH, Ecole des Mines de Nantes, IN2P3/CNRS, Université de Nantes, France Abstract. The French research on cosmic rays in the first half of the 20th century is summarized. The main experiments are described as the discovery of air cosmic ray

Paris-Sud XI, Université de

253

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

NASA Technical Reports Server (NTRS)

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

Barghouty, A. F.

2009-01-01

254

Cosmic rays from primordial black holes  

NASA Technical Reports Server (NTRS)

The quark and gluon emission from primordial black holes (PBHs) which may have formed from initial density perturbations or phase transitions in the early universe are investigated. If the PBHs formed from scale-invariant initial density perturbations in the radiation dominated era, it is found that the emission can explain or contribute significantly to the extragalactic photon and interstellar cosmic-ray electron, positron, and antiproton spectra around 0.1-1 GeV. In particular, the PBH emission strongly resembles the cosmic-ray gamma-ray spectrum between 50 and 170 MeV. The upper limits on the PBH density today from the gamma-ray, e(+), e(-), and antiproton data are comparable, provided that the PBHs cluster to the same degree as the other matter in the Galactic halo.

Macgibbon, Jane H.; Carr, B. J.

1991-01-01

255

Accelerator Data for Cosmic Ray Physics  

E-print Network

I present selected examples of accelerator data, mainly from hadron colliders, that are relevant for understanding cosmic ray showers. I focus on the forward region, $x_{Feynman} > 0.05$, where high energy data are scarce, since the emphasis in collider physics became high-$p_T$ phenomena.

M. G. Albrow

2010-09-21

256

Numerical likelihood analysis of cosmic ray anisotropies  

SciTech Connect

A numerical likelihood approach to the determination of cosmic ray anisotropies is presented which offers many advantages over other approaches. It allows a wide range of statistically meaningful hypotheses to be compared even when full sky coverage is unavailable, can be readily extended in order to include measurement errors, and makes maximum unbiased use of all available information.

Carlos Hojvat et al.

2003-07-02

257

Terrestrial Effects of High Energy Cosmic Rays  

E-print Network

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...

Atri, Dimitra

2011-04-26

258

Abundances and Acceleration Mechanisms of Cosmic Rays  

Microsoft Academic Search

MEASUREMENTS of the chemical composition of cosmic rays1 have shown that for most elements the abundances roughly correspond to their universal abundances. I wish to point out here that some systematic differences occur in the low energy range, which are correlated with the first ionization potentials of the corresponding elements.

Ove Havnes

1971-01-01

259

Cosmic Ray Origin, Acceleration and Propagation  

NASA Technical Reports Server (NTRS)

This paper summarizes highlights of the OG3.1, 3.2 and 3.3 sessions of the 26th International Cosmic Ray Conference in Salt Lake City, which were devoted to issues of origin/composition, acceleration and propagation.

Baring, Matthew G.

2000-01-01

260

COSMIC-RAY NEUTRON ENERGY SPECTRUM  

Microsoft Academic Search

The cosmic-ray neutron energy spectrum in the equilibrium region of the ; atmosphere was measured with several different calibrated detectors from thermal ; energies to about 1 Bev at 44 deg north magnetic latitude and up to 40,000 feet. ; By combination of the data from these measurements with those from other ; experiments, a complete differential energy spectrum is

Wilmot Hess; H. W. Patterson; Roger Wallace; Edward Chupp

1959-01-01

261

Exotic physics with ultrahigh energy cosmic rays  

E-print Network

Ultrahigh energy cosmic rays provide a unique ground for probing new physics. In this talk we review the possibility of testing TeV gravity in interactions of cosmogenic neutrinos and the potential to discover long-lived exotic particles in nucleon-produced air showers, such as gluinos of split-SUSY models or staus of supersymmetric models with a gravitino LSP.

M. Ahlers; J. I. Illana; M. Masip; D. Meloni

2007-10-02

262

Cosmic Ray Transport in Turbulent Magnetic Field  

NASA Astrophysics Data System (ADS)

Cosmic ray (CR) transport and acceleration are determined by the properties of magnetic turbulence. Recent advances in MHD turbulence call for revisions in the paradigm of cosmic ray transport. We use the models of magnetohydrodynamic turbulence that were tested in numerical simulation, in which turbulence is injected at large scale and cascades to small scales. We shall address the issue of the transport of CRs, both parallel and perpendicular to the magnetic field. Both normal diffusion on large scales and superdiffusion on small scales shall be addressed. We shall demonstrate compressible fast modes are the dominant cosmic ray scatterer from both quasilinear and nonlinear theories. We shall also show that the self-generated wave growth by CRs is constrained by preexisting turbulence and discuss the process in detail in the context of shock acceleration at supernova remnants and their implications. In addition, we shall dwell on the nonlinear growth of kinetic gyroresonance instability of cosmic rays induced by large scale compressible turbulence. The feedback of the instability on large scale turbulence should be included in future simulations.

Yan, Huirong

263

A database of charged cosmic rays  

NASA Astrophysics Data System (ADS)

Aims: This paper gives a description of a new online database and associated online tools (data selection, data export, plots, etc.) for charged cosmic-ray measurements. The experimental setups (type, flight dates, techniques) from which the data originate are included in the database, along with the references to all relevant publications. Methods: The database relies on the MySQL5 engine. The web pages and queries are based on PHP, AJAX and the jquery, jquery.cluetip, jquery-ui, and table-sorter third-party libraries. Results: In this first release, we restrict ourselves to Galactic cosmic rays with Z ? 30 and a kinetic energy per nucleon up to a few tens of TeV/n. This corresponds to more than 200 different sub-experiments (i.e., different experiments, or data from the same experiment flying at different times) in as many publications. Conclusions: We set up a cosmic-ray database (CRDB) and provide tools to sort and visualise the data. New data can be submitted, providing the community with a collaborative tool to archive past and future cosmic-ray measurements. http://lpsc.in2p3.fr/crdb; Contact: crdatabase@lpsc.in2p3.fr

Maurin, D.; Melot, F.; Taillet, R.

2014-09-01

264

A Geographic Study of Cosmic Rays  

Microsoft Academic Search

Data are given from measurements of the intensity of cosmic rays by 8 different expeditions at 69 stations distributed at representative points over the earth's surface. Each set of apparatus consisted of a 10 cm spherical steel ionization chamber filled with argon at 30 atmospheres, connected to a Lindemann electrometer, and shielded with 2.5 cm of bronze plus 5.0 cm

Arthur H. Compton

1933-01-01

265

Cosmic Ray Transport in the Distant Heliosheath  

NASA Technical Reports Server (NTRS)

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.

Florinski, V.; Adams, James H.; Washimi, H.

2011-01-01

266

Dark Matter Decay and Cosmic Rays  

E-print Network

The decay of dark matter is predicted by many theoretical models and can produce observable contributions to the cosmic-ray fluxes. I shortly discuss the interpretation of the positron and electron excess as observed by PAMELA and Fermi LAT in terms of decaying dark matter, and I point out the implications for the Fermi LAT observations of the gamma-ray flux with emphasis on its dipole-like anisotropy.

Weniger, Christoph

2009-01-01

267

In Search of Cosmic Rays: A Student Physics Project Aimed at Finding the Origin of Cosmic Rays.  

ERIC Educational Resources Information Center

Describes an ongoing project, the Cosmic Ray Observatory Project (CROP), being conducted by the University of Nebraska in partnership with several high schools. Each school group has installed cosmic ray detectors, and initial activities have included calibrating equipment, gathering preliminary data, and learning about cosmic ray showers. Aims to

Antonelli, Jamie; Mahoney, Sean; Streich, Derek; Liebl, Michael

2001-01-01

268

29th International Cosmic Ray Conference Pune (2005) 2, 5356 The role of drifts in the galactic cosmic ray transport  

E-print Network

29th International Cosmic Ray Conference Pune (2005) 2, 53­56 The role of drifts in the galactic cosmic ray transport K. Alanko , I.G. Usoskin ¡ and K. Mursula (a) Department of Physical Sciences, P-poster We have earlier presented a 2D-axisymmetric model of the transport of galactic cosmic rays

Usoskin, Ilya G.

269

Concerning the Nature of the Cosmic Ray Power Law Exponents  

E-print Network

We have recently shown that the cosmic ray energy distributions as detected on earthbound, low flying balloon or high flying satellite detectors can be computed by employing the heats of evaporation of high energy particles from astrophysical sources. In this manner, the experimentally well known power law exponents of the cosmic ray energy distribution have been theoretically computed as 2.701178 for the case of ideal Bose statistics, 3.000000 for the case of ideal Boltzmann statistics and 3.151374 for the case of ideal Fermi statistics. By "ideal" we mean virtually zero mass (i.e. ultra-relativistic) and noninteracting. These results are in excellent agreement with the experimental indices of 2.7 with a shift to 3.1 at the high energy ~ PeV "knee" in the energy distribution. Our purpose here is to discuss the nature of cosmic ray power law exponents obtained by employing conventional thermal quantum field theoretical models such as quantum chromodynamics to the cosmic ray sources in a thermodynamic scheme w...

Widom, A; Srivastava, Y N

2014-01-01

270

29th International Cosmic Ray Conference Pune (2005) 00, 101106 A Search for Short Duration VHE Emission from GRBs with Milagro  

E-print Network

29th International Cosmic Ray Conference Pune (2005) 00, 101­106 A Search for Short Duration VHE Mountains near Los Alamos, New Mex- ico, and is capable of detecting air showers induced by cosmic rays emission from GRBs. Due to the large cosmic-ray flux at the earth, the bulk of the events detected

California at Santa Cruz, University of

271

TRACING THE SOURCES OF COSMIC RAYS WITH MOLECULAR IONS  

SciTech Connect

The rate of ionization by cosmic rays (CRs) in interstellar gas directly associated with {gamma}-ray-emitting supernova remnants (SNRs) is for the first time calculated to be several orders of magnitude larger than the Galactic average. Analysis of ionization-induced chemistry yields the first quantitative prediction of the astrophysical H{sup +} {sub 2} emission line spectrum, which should be detectable together with H{sup +} {sub 3} lines. The predicted coincident observation of those emission lines and {gamma}-rays will help prove that SNRs are sources of CRs.

Becker, Julia K.; Schuppan, Florian [Ruhr-Universitaet Bochum, Fakultaet fuer Physik and Astronomie, Theoretische Physik IV, D-44780 Bochum (Germany); Black, John H.; Mohammadtaher Safarzadeh, E-mail: julia@tp4.rub.de [Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, SE-439 92 Onsala (Sweden)

2011-10-01

272

Ultra-high energy cosmic rays  

NASA Astrophysics Data System (ADS)

Experimental efforts to reveal the nature and origin of cosmic rays with energy above 1018 eV led to several important steps forward in recent years. The existence of a suppression of the flux above 41019 eV has been confirmed. It occurs at the energy threshold for pion-production in proton collisions with the cosmic microwave background, as anticipated almost fifty years ago. The flux measurements alone are however insufficient to confidently establish whether the suppression is due to energy loss effects along propagation over cosmological distances, or else because the sources reach their maximum acceleration power. There are indications obtained with the Pierre Auger Observatory of a trend from a light towards a heavier composition as the energy increases. There is some tension between these indications and those from the HiRes and Telescope Array experiments, which are compatible with a pure proton composition. This is a most important issue to be settled in the near future. At present there is no statistically significant evidence for anisotropy in the distribution of arrival directions at the highest energies that could favor one specific astrophysical scenario for cosmic ray origin over another. There are hints for a large scale pattern in the distribution of arrival directions that need to be confirmed with independent data. In this paper we summarize recent measurements of the energy spectrum of cosmic rays with the highest energies, the evidence for their composition, and the searches for anisotropies in the distribution of their arrival directions.

Harari, Diego

2014-09-01

273

Angular correlation of cosmic neutrinos with ultrahigh-energy cosmic rays and implications for their sources  

E-print Network

Cosmic neutrino events detected by the IceCube Neutrino Observatory with energy $\\gtrsim 30$ TeV have poor angular resolutions to reveal their origin. Ultrahigh-energy cosmic rays (UHECRs), with better angular resolutions at $>60$ EeV energies, can be used to check if the same astrophysical sources are responsible for producing both neutrinos and UHECRs. We test this hypothesis, with statistical methods which emphasize invariant quantities, by using data from the Pierre Auger Observatory, Telescope Array and past cosmic-ray experiments. We find that the arrival directions of the cosmic neutrinos are correlated with $\\ge 100$ EeV UHECR arrival directions at confidence level $\\approx 93\\%$. The strength of the correlation decreases with decreasing UHECR energy and no correlation exists at energy $\\sim 60$ EeV. A search in astrophysical databases within $3^\\circ$ of the arrival directions of UHECRs with energy $\\ge 100$ EeV, that are correlated with the IceCube cosmic neutrinos, resulted in 18 sources from the S...

Moharana, Reetanjali

2015-01-01

274

Neutrinos associated with cosmic rays of top-down origin  

NASA Astrophysics Data System (ADS)

Top-down models of cosmic rays produce more neutrinos than photons and more photons than protons. In these models, we reevaluate the fluxes of neutrinos associated with the highest energy cosmic rays in light of mounting evidence that they are protons and not gamma rays. While proton dominance at EeV energies can possibly be achieved by efficient absorption of the dominant high-energy photon flux on universal and galactic photon and magnetic background fields, we show that the associated neutrino flux is inevitably increased to a level where it might be within reach of operating experiments such as AMANDA II, RICE and AGASA. In future neutrino telescopes, tens to a hundred, rather than a few neutrinos per kilometer squared per year, may be detected above 100 TeV.

Barbot, C.; Drees, M.; Halzen, F.; Hooper, D.

2003-02-01

275

Cosmic-ray Exposure Ages of Meteorites  

NASA Astrophysics Data System (ADS)

The classic idea of a cosmic-ray exposure (CRE) age for a meteorite is based on a simple but useful picture of meteorite evolution, the one-stage irradiation model. The precursor rock starts out on a parent body, buried under a mantle of material many meters thick that screens out cosmic rays. At a time ti, a collision excavates a precursor rock - a "meteoroid." The newly liberated meteoroid, now fully exposed to cosmic rays, orbits the Sun until a time tf, when it strikes the Earth, where the overlying blanket of air (and possibly of water or ice) again shuts out almost all cosmic rays (cf. Masarik and Reedy, 1995). The quantity tf-ti is called the CRE age, t. To obtain the CRE age of a meteorite, we measure the concentrations in it of one or more cosmogenic nuclides (Table 1), which are nuclides that cosmic rays produce by inducing nuclear reactions. Many shorter-lived radionuclides excluded from Table 1 such as 22Na (t1/2=2.6 yr) and 60Co (t1/2=5.27 yr) can also furnish valuable information, but can be measured only in meteorites that fell within the last few half-lives of those nuclides (see, e.g., Leya et al. (2001) and references therein). Table 1. Cosmogenic nuclides used for calculating exposure ages NuclideHalf-lifea (Myr) Radionuclides 14C0.005730 59Ni0.076 41Ca0.1034 81Kr0.229 36Cl0.301 26Al0.717 10Be1.51 53Mn3.74 129I15.7 Stable nuclides 3He 21Ne 38Ar 83Kr 126Xe a http://www2.bnl.gov/ton. CRE ages have implications for several interrelated questions. From how many different parent bodies do meteorites come? How well do meteorites represent the population of the asteroid belt? How many distinct collisions on each parent body have created the known meteorites of each type? How often do asteroids collide? How big and how energetic were the collisions that produced meteoroids? What factors control the CRE age of a meteorite and how do meteoroid orbits evolve through time? We will touch on these questions below as we examine the data.By 1975, the CRE ages of hundreds of meteorites had been estimated from noble gas measurements. Histograms of the CRE age distributions pointed to several important observations.(i) The CRE ages of meteorites increase in the order stones detection limits for cosmogenic nuclides and

Herzog, G. F.

2003-12-01

276

The Effect of Cosmic Ray Diffusion on the Parker Instability  

E-print Network

The Parker instability, which has been considered as a process governing the structure of the interstellar medium, is induced by the buoyancy of magnetic field and cosmic rays. In previous studies, while the magnetic field has been fully incorporated in the context of isothermal magnetohydrodynamics, cosmic rays have been normally treated with the simplifying assumption of infinite diffusion along magnetic field lines but no diffusion across them. The cosmic ray diffusion is, however, finite. In this work, we take into account fully the diffusion process of cosmic rays in a linear stability analysis of the Parker instability. Cosmic rays are described with the diffusion-convection equation. With realistic values of cosmic ray diffusion coefficients expected in the interstellar medium, we show that the result of previous studies with the simplifying assumption on cosmic ray diffusion applies well. Finiteness of parallel diffusion decreases the growth rate of the Parker instability, while the relatively smaller...

Ryu, D; Hong, S S; Jones, T W; Ryu, Dongsu; Kim, Jongsoo; Hong, Seung Soo

2003-01-01

277

The elemental and isotopic composition of galactic cosmic rays  

NASA Technical Reports Server (NTRS)

Galactic cosmic rays represent samples of matter from areas outside the solar system. New information regarding the elemental composition of cosmic rays has been obtained in connection with the French-Danish experiment on HEA0-3 and recent balloon experiments. The energy dependence of the source composition is considered along with a comparison of cosmic ray and solar system abundances, and the N-14 source abundance. Attention is given to cosmic ray clocks and the Mn-54 problem, advances concerning cross section measurements, and cosmic ray isotopes. The considered new observations suggest that cosmic ray elemental abundance differences from the solar system continue to be ordered by atomic parameters such as first ionization potential, at least up through Z equals 40. The isotopic composition of the cosmic ray source is found to be unlike that of the solar system.

Mewaldt, R. A.

1982-01-01

278

Simulation of Cosmic Ray neutrinos Interactions in Water  

E-print Network

The program CORSIKA, usually used to simulate extensive cosmic ray air showers, has been adapted to a water medium in order to study the acoustic detection of ultra high energy neutrinos. Showers in water from incident protons and from neutrinos have been generated and their properties are described. The results obtained from CORSIKA are compared to those from other available simulation programs such as Geant4.

T. Sloan

2006-10-09

279

Further observations of geomagnetically forbidden cosmic ray nuclei  

NASA Technical Reports Server (NTRS)

Cosmic-ray particles with kinetic energies well below cutoff values were detected during a high-altitude balloon flight at 41 deg N geomagnetic latitude. These particles had kinetic energies up to 400 MeV/amu and charges in the range from 6 to 30. They are probably reentrant albedo particles and are of interest primarily because they can be confused with fast ultraheavy primary particles in some experiments.

Friedlander, M. W.; Hoppe, M.

1977-01-01

280

Cosmic rays studied with a hybrid high school detector array  

E-print Network

The LORUN/NAHSA system is a pathfinder for hybrid cosmic ray research combined with education and outreach in the field of astro-particle physics. Particle detectors and radio antennae were mainly setup by students and placed on public buildings. After fully digital data acquisition, coincidence detections were selected. Three candidate events confirmed a working prototype, which can be multiplied to extend further particle detector arrays on high schools.

A. Nigl; C. Timmermans; P. Schellart; J. Kuijpers; H. Falcke; A. Horneffer; C. M. de Vos; Y. Koopman; H. J. Pepping; G. Schoonderbeek

2008-09-16

281

Nuclear composition of solar cosmic rays  

NASA Technical Reports Server (NTRS)

Experimental observations of the elemental and isotopic composition of solar flare particles are discussed. Sources and characteristics of particle-emitting solar flare events are reviewed, and techniques for separating particle species are briefly described. Data are presented for the elemental composition of the solar atmosphere, and the possibility of determining the solar helium abundance from solar cosmic-ray observations is explored. The main experimental determinations of heavy element abundances at energies greater and less than 10 MeV/nucleon are summarized, and techniques for measuring the ionic charge composition of solar cosmic rays are outlined. Models explaining heavy element enhancements are described along with processes leading to gamma-ray emission during solar flare events. Observations of the rare isotopes of hydrogen and helium during solar flare events are noted, and a lower atmospheric limit is derived for nuclear reactions leading to positron decay. The possibility of investigating low-energy solar cosmic rays by measuring the relative abundances of different elements is evaluated.

Hovestadt, D.

1974-01-01

282

Time correlation of cosmic-ray-induced neutrons and gamma rays at sea level  

E-print Network

Time correlation of cosmic-ray-induced neutrons and gamma rays at sea level G. Miloshevsky n , A November 2013 Keywords: Cosmic rays Multiplicity Coincidence Correlation Poisson distribution Feynman-Y statistic a b s t r a c t The neutrons and gamma rays produced by cosmic ray interactions in spallation

Harilal, S. S.

283

Terrestrial effects of high energy cosmic rays  

NASA Astrophysics Data System (ADS)

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.

Atri, Dimitra

284

Ultra-high energy cosmic rays: Observational results  

NASA Astrophysics Data System (ADS)

The study of ultra-high energy cosmic rays has experienced a jump in statistics as well as improved instrumentation. The number of detected cosmic rays has increased by more than a factor of ten over the past decade, and measurements are checked using multiple detection techniques. The energy spectrum clearly has a spectral hardening known as "the ankle" and also a "GZK-like" downturn above 1019.5 eV. Evidence of trans-GZK arrival directions correlating with AGNs and/or the large-scale matter distribution within the GZK sphere has not been confirmed so far. More data are needed to verify and understand that anisotropy. A search for neutron fluxes from discrete sources in the Galaxy has yielded no detection, and the neutron flux upper limits constrain models for EeV proton production. Additional constraint has come from measuring the first harmonic in right ascension of the cosmic ray arrival directions, which has yielded upper limits below 2% at energies up to 2 EeV.

Sommers, Paul

2012-12-01

285

Ultrahigh Energy Cosmic Rays: Old Physics or New Physics?  

NASA Astrophysics Data System (ADS)

We consider the advantages of and the problems associated with hypotheses to explain the origin of ultrahigh energy cosmic rays (UHECR: E > 10 EeV) and the trans-GZK cosmic rays (TGZK: E > 100 EeV) both through old physics (acceleration in cosmic sources) and new physics (new particles, topological defects, fat neutrino cross sections, Lorentz invariance violation).

Stecker, F. W.

2004-11-01

286

Cosmic-ray knee and flux of secondaries from interactions of cosmic rays with dark matter  

E-print Network

We discuss possible implications of a large interaction cross section between cosmic rays and dark matter particles due to new physics at the TeV scale. In particular, in models with extra dimensions and a low fundamental scale of gravity the cross section grows very fast at transplanckian energies. We argue that the knee observed in the cosmic ray flux could be caused by such interactions. We show that this hypothesis implies a well defined flux of secondary gamma rays that seems consistent with MILAGRO observations.

Manuel Masip; Iacopo Mastromatteo

2009-04-06

287

Cosmic rays & Neutrinos Historical development  

E-print Network

| Perm in hairdressing Deutsch The Neutrino Wolfgang Pauli's name is inseparable from his pioneering. The starting point for Pauli was the continuous energy spectrum of beta rays, which could not be interpreted conservation, which Pauli could not accept because the principle of the conservation of energy had proved

Gaisser, Thomas K.

288

High-energy Neutrino Astronomy: The Cosmic Ray Connection  

E-print Network

This is a review of neutrino astronomy anchored to the observational fact that Nature accelerates protons and photons to energies in excess of $10^{20}$ and $10^{13}$ eV, respectively. Although the discovery of cosmic rays dates back close to a century, we do not know how and where they are accelerated. Basic elementary-particle physics dictates a universal upper limit on their energy of $5\\times10^{19}$ eV, the so-called Greisen-Kuzmin-Zatsepin cutoff; however, particles in excess of this energy have been observed by all experiments, adding one more puzzle to the cosmic ray mystery. Mystery is fertile ground for progress: we will review the facts as well as the speculations about the sources including gamma ray bursts, blazars and top-down scenarios. The important conclusion is that, independently of the specific blueprint of the source, it takes a kilometer-scale neutrino observatory to detect the neutrino beam associated with the highest energy cosmic rays and gamma rays. We also briefly review the ongoing efforts to commission such instrumentation.

Francis Halzen; Dan Hooper

2002-07-08

289

Quantum Black Holes from Cosmic Rays  

E-print Network

We investigate the possibility for cosmic ray experiments to discover non-thermal small black holes with masses in the TeV range. Such black holes would result due to the impact between ultra high energy cosmic rays or neutrinos with nuclei from the upper atmosphere and decay instantaneously. They could be produced copiously if the Planck scale is in the few TeV region. As their masses are close to the Planck scale, these holes would typically decay into two particles emitted back-to-back. Depending on the angles between the emitted particles with respect to the center of mass direction of motion, it is possible for the simultaneous showers to be measured by the detectors.

Xavier Calmet; Lauretiu Ioan Caramete; Octavian Micu

2012-11-19

290

The Pierre Auger Cosmic Ray Observatory  

E-print Network

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 $10^{17}$ eV and to 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. In addition, three high elevation fluorescence telescopes overlook a 23.5 km$^2$, 61 detector infill array. The Observatory has been in successful operation 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 Auger Observatory.

,

2015-01-01

291

Cosmic Ray Electron Science with GLAST  

NASA Technical Reports Server (NTRS)

Cosmic ray electrons at high energy carry information about their sources, their definition in local magnetic fields and their interactions with the photon fields through which they travel. The spectrum of the particles is affected by inverse Compton losses and synchrotron losses, the rates of which are proportional to the square of the particle's energy making the spectra very steep. However, GLAST will be able to make unique and very high statistics measurements of electrons from approx. 20 to approx. 700 GeV that will allow us to search for anisotropies in anival direction and spectral features associated with some dark matter candidates. Complementary information on electrons of still higher energy will be required to see effects of possible individual cosmic ray sources.

Ormes, J. F.; Moiseev, Alexander

2007-01-01

292

Radiative Energy Loss by Galactic Cosmic Rays  

NASA Technical Reports Server (NTRS)

Interactions between galactic cosmic rays and matter are a primary focus of the NASA radiation problem. The electromagnetic forces involved are for the most part well documented. Building on previous research, this study investigated the relative importance of the weak forces that occur when a cosmic ray impinges on different types of materials. For the familiar electromagnetic case, it is known that energy lost in the form of radiation is more significant than that lost via contact collisions the rate at which the energy is lost is also well understood. Similar results were derived for the weak force case. It was found that radiation is also the dominant mode of energy loss in weak force interactions and that weak force effects are indeed relatively weak compared to electromagnetic effects.

Ahern, Sean C.; Norbury, John W.; Tripathi, R. K.

2002-01-01

293

The highest energy cosmic rays: Observations  

NASA Astrophysics Data System (ADS)

Observations of cosmic ray air showers with energies above 0.1 EeV (1017 eV) are key to understanding where the highest energy cosmic rays originate, how they acquire their energy, what types of particles they are, and also the nature of their ultra-high-energy hadronic interactions at the top of the atmosphere. Prominent features of the energy spectrum have now been established, although some difference remains in energy normalization between results from different observatories. A distinct ankle is present near 4 EeV, and a GZK-like downturn is evident above about 30 EeV. Well above that GZK threshold, there have been tantalizing indications of clustering of arrival directions and correlation with catalogs of local matter, but no anisotropy has been independently confirmed so far at any energy above 0.1 EeV. With 99% confidence, the dipole anisotropy is less than 2% for energies just below 1 EeV, as measured in right ascension from the southern hemisphere. Moreover, no discrete source of neutral particles has been discovered and astrophysically interesting upper limits have been derived. Although the present upper limits on the diffuse intensities of photons and neutrinos do not constrain typical models of GZK production, they have eliminated most top-down models in which cosmic rays originate through the annihilation or decay of supermassive particles. The vast majority of cosmic rays must be protons and other charged nuclei. Data from different observatories have led to inconsistent inferences about the relative abundances of primary mass groups and the dependence of the composition on energy. The effective proton-air interaction cross section has been measured at EeV energies and is in agreement with conventional extrapolations obtained from measurements at collider energies.

Sommers, Paul

2013-02-01

294

Phenomenology of cosmic ray air showers  

E-print Network

The properties of cosmic rays with energies above 1PeV have to be deduced from the spacetime structure and particle content of the air showers which they initiate. In this review, a summary of the phenomenology of these giant air showers is presented. We describe the hadronic interaction models used to extrapolate results from collider data to ultra high energies, an also the main electromagnetic processes that govern the longitudinal shower evolution as well as the lateral spread of particles.

M. T. Dova

2005-05-30

295

Altitude variation of cosmic-ray neutrons  

Microsoft Academic Search

The altitude variation of the cosmic-ray neutron energy spectrum and the dose equivalent rate was measured at an average geomagnetic latitude of 24 degrees N by using the high-efficiency multi-sphere neutron spectrometer and neutron dose-equivalent counter developed by the authors. The data were obtained from a 2-h flight over Japan on 27 February 1985. The neutron energy spectra measured at

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

1987-01-01

296

The Universe Viewed in Gamma-Rays 1 Galactic Diffuse Gamma-ray Spectrum from Cosmic-ray In-  

E-print Network

The Universe Viewed in Gamma-Rays 1 Galactic Diffuse Gamma-ray Spectrum from Cosmic-ray In- teractions with Gas Clouds Michiko OHISHI and Masaki MORI Institute for Cosmic Ray Research, University, Australia Abstract Gamma-ray spectra from cosmic-ray proton and electron interactions with gas clouds have

Mori, Masaki

297

Cosmic rays in the heliosphere: Observations  

NASA Astrophysics Data System (ADS)

This contribution to the 100th commemoration of the discovery of cosmic rays (6-8 August, 2012 in Bad Saarow, Germany) is about observations of those cosmic rays that are sensitive to the structure and the dynamics of the heliosphere. This places them in the energy range of 107-1010 eV. For higher energies the heliosphere becomes transparent; below this energy range the particles become strictly locked into the solar wind. Rather than give a strict chronological development, the paper is divided into distinct topics. It starts with the Pioneer/Voyager missions to the outer edges of the heliosphere, because the most recent observations indicate that a distinct boundary of the heliosphere might have been reached at the time of the meeting. Thereafter, the Ulysses mission is described as a unique one because it is still the only spacecraft that has explored the heliosphere at very high latitudes. Next, anomalous cosmic rays, discovered in 1972-1974, constitute a separate component that is ideally suited to study the acceleration and transport of energetic particles in the heliosphere. At this point the history and development of ground-based observations is discussed, with its unique contribution to supply a stable, long-term record. The last topic is about solar energetic particles with energies up to ?1010 eV.

Moraal, Harm

2014-01-01

298

Cosmic ray ionization of the Jovian atmosphere  

NASA Technical Reports Server (NTRS)

An approximate form of the Boltzmann equation has been used to obtain local ionization rates due to the absorption of galactic cosmic rays in the Jovian atmosphere. It is shown that the muon flux component of the cosmic-ray-induced cascade may be especially important in ionizing the atmosphere at levels where the total number density exceeds 10 to the 19th per cu cm (well below the ionospheric layers produced by solar EUV). A model containing both positive and negative ion reactions has been employed to compute electron and ion number densities. Peak electron number densities of the order of 1000 per cu cm may be expected even at relatively low magnetic latitudes. The dominant positive ions are NH4(+) and CnHm(+) cluster ions, with n at least 2; it is suggested that the absorption of galactic cosmic-ray energy at such relatively high pressures in the Jovian atmosphere (M about 10 to the 18th to 10 to the 20th per cu cm) and the subsequent chemical reactions may be instrumental in the local formation of complex hydrocarbons.

Capone, L. A.; Dubach, J.; Whitten, R. C.; Prasad, S. S.

1979-01-01

299

Time-dependent cosmic ray modulation  

NASA Astrophysics Data System (ADS)

Time-dependent cosmic ray modulation is calculated over multiple solar cycles using our well established two-dimensional time-dependent modulation model. Results are compared to Voyager 1, Ulysses and IMP cosmic ray observations to establish compatibility. A time-dependence in the diffusion and drift coefficients, implicitly contained in recent expressions derived by Teufel and Schlickeiser (2002), Shalchi et al. (2004), Minnie et al. (2007), Engelbrecht (2008), is incorporated into the cosmic ray modulation model. This results in calculations which are compatible with spacecraft observations on a global scale over consecutive solar cycles. This approach compares well to the successful compound approach of Ferreira and Potgieter (2004). For both these approaches the magnetic field magnitude, variance of the field and current sheet tilt angle values observed at Earth are transported time-dependently into the outer heliosphere. However, when results are compared to observations for extreme solar maximum, the computed step-like modulation is not as pronounced as observed. This indicates that some additional merging of these structures into more pronounced modulation barriers along the way is needed.

Manuel, R.; Ferreira, S. E. S.; Potgieter, M. S.; Strauss, R. D.; Engelbrecht, N. E.

2011-05-01

300

Modulation of low-energy cosmic rays  

NASA Technical Reports Server (NTRS)

The relation between the diffusion coefficient of cosmic rays in the solar wind and the power spectrum of interplanetary magnetic field fluctuations, established in recent theories, is tested directly for low energy protons (below 80 MeV). In addition, an attempt is made to determine whether the particles are scattered by magnetic field discontinuities or by fluctuations between discontinuities. Predictions of a perturbation solution of the Fokker-Planck equation are compared with observations of the cosmic ray radial gradient. It is found that at energies between 40 and 80 MeV, galactic cosmic ray protons respond to changes in the predicted diffusion coefficients (i.e., the relationship under consideration holds at these low energies). The relation between changes in the proton flux and modulation parameters is best when the contribution of discontinuities is subtracted, which means that scattering is caused by fluctuations between discontinuities. There appears to be no distinct relation between changes in the modulation parameters and changes in the intensity of 20 to 40 MeV protons.

Sari, J. W.

1975-01-01

301

Cosmic rays from trans-relativistic supernovae  

E-print Network

We derive constraints that must be satisfied by the sources of ~10^{15} to ~10^{18} eV cosmic rays, under the assumption that the sources are Galactic. We show that while these constraints are not satisfied by ordinary supernovae (SNe), which are believed to be the sources of deposit a large fraction, f_R>10^{-2}, of their kinetic energy in mildly relativistic, \\gamma\\beta>1, ejecta. The high velocity ejecta enable particle acceleration to ~10^{18} eV, and the large value of f_R (compared to f_R~10^{-7} for ordinary SNe) ensures that if TRSNe produce the observed ~10^{18} eV cosmic ray flux, they do not overproduce the flux at lower energies. This, combined with the estimated rate and energy production of TRSNe, imply that Galactic TRSNe may be the sources of cosmic rays with energies up to ~10^{18}eV .

R. Budnik; B. Katz; A. MacFadyen; E. Waxman

2007-05-01

302

Cosmic ray anisotropies near the heliopause  

NASA Astrophysics Data System (ADS)

Context. The Voyager 1 spacecraft became the first man-made probe to cross the heliopause into the local interstellar medium and measure the galactic environment, including charged particle intensities, in situ. Aims: We qualitatively explain the observed anisotropies of galactic and anomalous cosmic rays in the interstellar medium. Methods: A pitch-angle-dependent numerical model was constructed and applied to the study of both heliospheric (anomalous cosmic rays and termination shock particles) and galactic cosmic rays near the heliopause region. Results: In accordance with the observations, the model is able to reproduce the observed anisotropic nature of both particle populations. In the interstellar medium, the heliospheric particle distribution shows a peak at pitch angles near 90, while for galactic particles, their distribution shows a deficiency at these pitch-angle values. Conclusions: The observed anisotropies are related to the pitch-angle dependence of the perpendicular diffusion coefficient, and if this dependence is chosen appropriately, the anisotropies observed by Voyager 1 can be explained naturally.

Strauss, R. D.; Fichtner, H.

2014-12-01

303

Ultra high-energy cosmic ray observations  

NASA Astrophysics Data System (ADS)

The year 2007 has furnished us with outstanding results about the origin of the most energetic cosmic rays: a flux suppression as expected from the GZK-effect has been observed in the data of the HiRes and Auger experiments and correlations between the positions of nearby AGN and the arrival directions of trans-GZK events have been observed by the Pierre Auger Observatory. The latter finding marks the beginning of ultra high-energy cosmic ray astronomy and is considered a major breakthrough starting to shed first light onto the sources of the most extreme particles in nature. This report summarizes those observations and includes other major advances of the field, mostly presented at the 30th International Cosmic Ray Conference held in Mrida, Mexico, in July 2007. With increasing statistics becoming available from current and even terminated experiments, systematic differences amongst different experiments and techniques can be studied in detail which is hoped to improve our understanding of experimental techniques and their limitations.

Kampert, K.-H.

2008-07-01

304

Erich Regener - a forgotten cosmic ray pioneer  

NASA Astrophysics Data System (ADS)

In the 1930s the German physicist Erich Regener (1881-1955), did important work on the measurement of the rate production of ionisation in the atmosphere and deep under-water. He discovered, along with one of his students, Georg Pfotzer, the altitude at which the production of ionisation in the atmosphere reaches a maximum, often and misleadingly called the Pfotzer maximum. He was one of the first to estimate the energy density of cosmic rays, an estimate used by Baade and Zwicky to postulate that supernovae might be the source of cosmic rays. Yet Regener's name is little known largely because he was forced to take early retirement by the National Socialists in 1937 as his wife had Jewish ancestors. In this paper we review his work on cosmic rays and the subsequent influence that he had on the subject through his son, his son-in-law, his grandson and his students. He was nominated for the Nobel Prize in Physics by Schroedinger in 1938. He died in 1955 at the age of 73.

Carlson, Per; Watson, Alan

2013-04-01

305

SUPERNOVA REMNANT KES 17: AN EFFICIENT COSMIC RAY ACCELERATOR INSIDE A MOLECULAR CLOUD  

SciTech Connect

The supernova remnant Kes 17 (SNR G304.6+0.1) is one of a few but growing number of remnants detected across the electromagnetic spectrum. In this paper, we analyze recent radio, X-ray, and ?-ray observations of this object, determining that efficient cosmic ray acceleration is required to explain its broadband non-thermal spectrum. These observations also suggest that Kes 17 is expanding inside a molecular cloud, though our determination of its age depends on whether thermal conduction or clump evaporation is primarily responsible for its center-filled thermal X-ray morphology. Evidence for efficient cosmic ray acceleration in Kes 17 supports recent theoretical work concluding that the strong magnetic field, turbulence, and clumpy nature of molecular clouds enhance cosmic ray production in supernova remnants. While additional observations are needed to confirm this interpretation, further study of Kes 17 is important for understanding how cosmic rays are accelerated in supernova remnants.

Gelfand, Joseph D. [NYU Abu Dhabi, P.O. Box 903, New York, NY 10276 (United States); Castro, Daniel [MIT Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Avenue 37-241, Cambridge, MA 02139 (United States); Slane, Patrick O. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Temim, Tea [Observational Cosmology Lab, Code 665, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Hughes, John P. [Department of Physics and Astronomy Rutgers University 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Rakowski, Cara, E-mail: jg168@cosmo.nyu.edu, E-mail: cara.rakowski@gmail.com [United States Patent and Trademark Office, 600 Dulany Street, Alexandria, VA (United States)

2013-11-10

306

29th International Cosmic Ray Conference Pune (2005) 00, 101-104 Front End Electronics for Calorimetry in Space  

E-print Network

29th International Cosmic Ray Conference Pune (2005) 00, 101-104 Front End Electronics) and will record several billions cosmic rays per year of operation. The ECAL frond-end read-out was designed topological trigger for the detection of gamma-ray showers. It will be described in detail with the main

Boyer, Edmond

307

Cosmic Ray and Tev Gamma Ray Generation by Quasar Remnants  

NASA Technical Reports Server (NTRS)

Results from new broadband (radio to X-ray) high-resolution imaging studies of the dormant quasar remnant cores of nearby giant elliptical galaxies are now shown to permit the harboring of compact dynamos capable of generating the highest energy cosmic ray particles and associated curvature radiation of TeV photons. Confirmation would imply a global inflow of interstellar gas all the way to the accretion powered supermassive black hole at the center of the host galaxy.

Boldt, Elihu; Loewenstein, Michael; White, Nicholas E. (Technical Monitor)

2000-01-01

308

[gamma]-ray signatures from ordinary cosmic strings  

SciTech Connect

We calculate the flux of ultrahigh-energy photons from individual ordinary (i.e., nonsuperconducting) cosmic strings and compare the results with the sensitivity of current and proposed TeV and EeV telescopes. Our calculations give only upper limits for the [gamma]-ray flux, since the source of the photons, jets from particle production at cusps, may be weakened by back-reaction effects. For the usual cosmic distribution of strings, the predicted bursts from strings with the value of mass per unit length associated with galaxy formation or light strings may just be detectable. A diffuse [gamma]-ray background from light strings may also be seen by the Fly's Eye detector at above 7[times]10[sup 10] GeV.

MacGibbon, J.H. (Code 665, NASA/Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States)); Brandenberger, R.H. (Department of Physics, Brown University, Providence, Rhode Island 02912 (United States))

1993-03-15

309

Ground detectors for the study of cosmic ray showers  

NASA Astrophysics Data System (ADS)

We describe the work that we have done over the last decade to design and construct instruments to measure properties of cosmic rays in Mexico. We describe the detection of decaying and crossing muons in a water Cherenkov detector and discuss an application of these results to calibrate water Cherenkov detectors. We also describe a technique to separate isolated isolated muons and electrons in water Cherenkov detector. Next we describe the design and performance of a hybrid extensive air shower detector array built on the Campus of the University of Puebla (19N, 90W, 800 g/cm2) to measure the energy, arrival direction and composition of primary cosmic rays with energies around 1 PeV.

Salazar, H.; Villasenor, L.

2008-06-01

310

The Solar and Cosmic-Ray Synodic Periodicity (1969 1998)  

NASA Astrophysics Data System (ADS)

The synodic recurrence of the Mt. Wilson plage index (MPSI) and the Calgary cosmic ray (CR) intensity is investigated, using the wavelet power spectra in the range of 18 38 days, during the last three solar cycles. The unique temporal coincidence between the quasi synodic MPSI and the CR periods is detected in 1978 1982 (the 21st solar cycle). In the 22nd cycle there is a very strong MPSI synodic recurrence, from 1989.5 to 1990.5, but it is absent in the CR data. In 1992.5 1993.5 the MPSI and CR recurrence phenomenon is in good accordance with the solar wind speed and cosmic ray modulation as measured during the first Ulysses passage around the Sun. The Gnevyshev gap is present in the 27-day recurrence of CR, in agreement with Kudela et al. (1999).

Antalov, A.; Kudela, K.; Rybk, J.

2001-05-01

311

Statistical properties of the time histories of cosmic gamma-ray bursts detected by the BATSE experiment of the Compton gamma-ray observatory  

NASA Technical Reports Server (NTRS)

The main scientific objectives of the project were: (1) Calculation of average time history for different subsets of BATSE gamma-ray bursts; (2) Comparison of averaged parameters and averaged time history for different Burst And Transient Source Experiments (BASTE) Gamma Ray Bursts (GRB's) sets; (3) Comparison of results obtained with BATSE data with those obtained with APEX experiment at PHOBOS mission; and (4) Use the results of (1)-(3) to compare current models of gamma-ray bursts sources.

Sagdeev, Roald

1995-01-01

312

Cosmic Ray Positrons from Pulsars  

NASA Technical Reports Server (NTRS)

Pulsars are potential Galactic sources of positrons through pair cascades in their magnetospheres. There are, however, many uncertainties in establishing their contribution to the local primary positron flux. Among these are the local density of pulsars, the cascade pair multiplicities that determine the injection rate of positrons from the pulsar, the acceleration of the injected particles by the pulsar wind termination shock, their rate of escape from the pulsar wind nebula, and their propagation through the interstellar medium. I will discuss these issues in the context of what we are learning from the new Fermi pulsar detections and discoveries.

Harding, Alice K.

2010-01-01

313

Wide field-of-view Cherenkov telescope for the detection of cosmic rays in coincidence with the surface detectors of the extensive air shower array  

E-print Network

The Yakutsk array group is developing the wide FOV Cherenkov telescope to be operated in coincidence with the surface detectors of the extensive air shower array. Currently, the engineering prototype of the reflecting telescope with the front-end electronics is designed and assembled to demonstrate the feasibility of a conceived instrument. The status and specifications of the prototype telescope are presented, as well as the modernization program of the Cherenkov light detectors subset of the array measuring ultra-high energy cosmic rays.

Ivanov, A A; Krasilnikov, A D; Petrov, Z E; Pravdin, M I; Sleptsov, I Ye; Timofeev, L V

2014-01-01

314

Wide field-of-view Cherenkov telescope for the detection of cosmic rays in coincidence with the Yakutsk extensive air shower array  

NASA Astrophysics Data System (ADS)

The Yakutsk array group is developing a wide field-of-view Cherenkov telescope to be operated in coincidence with the surface detectors of the extensive air shower array. Currently, the engineering prototype of the reflecting telescope with the front-end electronics is designed, assembled, and tested to demonstrate the feasibility of the conceived instrument. The status and specifications of the prototype telescope are presented, as well as the modernization program of the already existing Cherenkov light detectors subset of the array measuring ultra-high energy cosmic rays.

Ivanov, A. A.; Knurenko, S. P.; Krasilnikov, A. D.; Petrov, Z. E.; Pravdin, M. I.; Sleptsov, I. Ye.; Timofeev, L. V.

2015-02-01

315

Cosmic Ray Helium Intensities over the Solar Cycle from ACE  

NASA Technical Reports Server (NTRS)

Observations of cosmic-ray helium energy spectra provide important constraints on cosmic ray origin and propagation. However, helium intensities measured at Earth are affected by solar modulation, especially below several GeV/nucleon. Observations of helium intensities over a solar cycle are important for understanding how solar modulation affects galactic cosmic ray intensities and for separating the contributions of anomalous and galactic cosmic rays. The Cosmic Ray Isotope Spectrometer (CRIS) on ACE has been measuring cosmic ray isotopes, including helium, since 1997 with high statistical precision. We present helium elemental intensities between approx. 10 to approx. 100 MeV/nucleon from the Solar Isotope Spectrometer (SIS) and CRIS observations over a solar cycle and compare these results with the observations from other satellite and balloon-borne instruments, and with GCR transport and solar modulation models.

DeNolfo, G. A.; Yanasak, N. E.; Binns, W. R.; Cohen, C. M. S.; Cummings, A. C.; Davis, A. J.; George, J. S.; Hink. P. L.; Israel, M. H.; Lave, K.; Leske, R. A.; Mewaldt, R. A.; Moskalenko, I. V.; Ogliore, R.; Stone, E. C.; Von Rosenvinge, T. T.; Wiedenback, M. E.

2007-01-01

316

PeV neutrinos from intergalactic interactions of cosmic rays emitted by active galactic nuclei.  

PubMed

The observed very high energy spectra of distant blazars are well described by secondary gamma rays produced in line-of-sight interactions of cosmic rays with background photons. In the absence of the cosmic-ray contribution, one would not expect to observe very hard spectra from distant sources, but the cosmic ray interactions generate very high energy gamma rays relatively close to the observer, and they are not attenuated significantly. The same interactions of cosmic rays are expected to produce a flux of neutrinos with energies peaked around 1PeV. We show that the diffuse isotropic neutrino background from many distant sources can be consistent with the neutrino events recently detected by the IceCube experiment. We also find that the flux from any individual nearby source is insufficient to account for these events. The narrow spectrum around 1PeV implies that some active galactic nuclei can accelerate protons to EeV energies. PMID:23931348

Kalashev, Oleg E; Kusenko, Alexander; Essey, Warren

2013-07-26

317

Cosmic ray constraints on singlino-like dark matter candidates  

E-print Network

Recent results from direct detection experiments (Dama, CoGeNT), though subject to debate, seem to point toward a low mass (few GeV) dark matter (DM) particle. However, low mass DM candidates are not easily achieved in the MSSM nor NMSSM. As shown by some authors, singlet extensions of the MSSM can lead to GeV mass neutralinos and satisfy relic abundance constraints. We propose here to extract indirect detection constraints on these models in a generic way from cosmic-ray anti-proton measurements (PAMELA data)

Timur Delahaye; David Cerdeo; Julien Lavalle

2011-06-10

318

WMAP, Planck, cosmic rays and unconventional cosmologies  

E-print Network

The claim by Gurzadyan et al. that the cosmological sky is a weakly random one where "the random perturbation is a minor component of mostly regular signal" has given rise to a series of useful exchanges. The possibility that the Cosmic Microwave Background radiation (CMB) data present trends in this direction would have strong implications for unconventional cosmologies. Similarly, data on ultra-high energy cosmic rays may contain signatures from new Physics generated beyond the Planck scale. It therefore seems legitimate, from a phenomenological point of view, to consider pre-Big Bang cosmologies as well as patterns where standard particles would not be the ultimate constituents of matter and the presently admitted principles of Physics would not necessarily be the fundamental ones. We discuss here prospects for some noncyclic, nonstandard cosmologies.

Luis Gonzalez-Mestres

2011-10-27

319

Superheavy dark matter and ultrahigh energy cosmic rays  

E-print Network

The phase of inflationary expansion in the early universe produces superheavy relics in a mass window between 10^{12} GeV and 10^{14} GeV. Decay or annihilation of these superheavy relics can explain the observed ultrahigh energy cosmic rays beyond the Greisen-Zatsepin-Kuzmin cutoff. We emphasize that the pattern of cosmic ray arrival directions with energies beyond 20 EeV will decide between the different proposals for the origin of ultrahigh energy cosmic rays.

R. Dick; K. M. Hopp; K. E. Wunderle

2005-08-01

320

A search for Extragalactic Sources of Ultrahigh-Energy Cosmic Rays  

E-print Network

Possible extragalactic sources of cosmic rays at energies above 4*10^{19} eV detected with the Yakutsk array are sought. Correlation of the shower arrival directions with objects from Veron's catalog that are located closer than 100 Mpc from the Earth confirms the observations at the Pierre Auger observatory, as well as the Greisen-Zatsepin-Kuzmin effect on ultrahigh-energy cosmic rays. The detailed analysis of the data reveals the classes of objects belonging to the active galactic nuclei that are probable sources of ultrahigh-energy cosmic rays.

A. A. Ivanov; for the Yakutsk array group

2008-03-05

321

CRAnE: A JAS-based Data Acquisition System for Cosmic Rays  

SciTech Connect

Cosmic Ray Analysis Environment (CRAnE) is a software tool designed to collect and plot data from a cosmic ray telescope (CRT) connected to a computer serial port. As a plug-in to Java Analysis Studio (JAS), CRAnE provides visual displays of incoming cosmic ray rates as they are detected. In an effort to make the program user-friendly, it operates through a graphical user interface. This paper describes the features of CRAnE and includes installation and operation instructions in the appended user's manual.

Langeveld, Willy G.J.

2003-08-25

322

The contribution of cosmic rays to global warming  

NASA Astrophysics Data System (ADS)

A search has been made for a contribution of the changing cosmic ray intensity to the global warming observed in the last century. The cosmic ray intensity shows a strong 11 year cycle due to solar modulation and the overall rate has decreased since 1900. These changes in cosmic ray intensity are compared to those of the mean global surface temperature to attempt to quantify any link between the two. It is shown that, if such a link exists, the changing cosmic ray intensity contributes less than 8% to the increase in the mean global surface temperature observed since 1900.

Sloan, T.; Wolfendale, A. W.

2011-10-01

323

Integral Neutron Multiplicity Measurements from Cosmic Ray Interactions in Lead  

NASA Astrophysics Data System (ADS)

Sixty element ^3He neutron multiplicity detector systems were designed, constructed and tested for use in cosmic ray experiments with a 30-cm cube lead target (306 kg). A series of measurements were performed for the cosmic ray configuration at ground level (3 meters water equivalent, mwe), in the St. Petersburg metro tunnel (185 mwe), and in the Pyh"asalmi mine in Finland (583 and 1185 mwe). Anomalous coincidence events with charged cosmic ray particles at sea level produced events with 100-120 neutrons due possibly to the total disintegration of the Pb nucleus. These events were also detected at 185 mwe, but the particles causing such disintegration are currently unidentified. A two layer 4?charged particle coincidence/anticoincidence system has been built and integrated into the system to help identify the charge of the originating particle events. Designs for a modular 100-cm cube lead target (11.35 mt) will be presented as well as examples of preliminary data from the various measurements and a discuss of future plans for underground experiments including possible searches for Weakly Interacting Massive Particles (WIMP, dark matter).

Ward, Thomas; Rimsky-Korsakov, Alexander; Kudryashev, Nikolai; Beller, Denis

2008-10-01

324

Lunar surface cosmic ray experiment S-152, Apollo 16  

NASA Technical Reports Server (NTRS)

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.

Fleischer, R. L.; Hart, H. R., Jr.; Carter, M.; Comostock, G. M.; Renshaw, A.; Woods, R. T.

1973-01-01

325

Transition from Galactic to extragalactic cosmic rays and cosmic ray anisotropy  

NASA Astrophysics Data System (ADS)

This talk based on results of ref. [1], where we constrain the energy at which the transition from Galactic to extragalactic cosmic rays occurs by computing the anisotropy at Earth of cosmic rays emitted by Galactic sources. Since the diffusion approximation starts to loose its validity for E/Z ? 10(16-17) eV, we propagate individual cosmic rays using Galactic magnetic field models and taking into account both their regular and turbulent components. The turbulent field is generated on a nested grid which allows spatial resolution down to fractions of a parsec. If the primary composition is mostly light or intermediate around E 1018 eV, the transition at the ankle is ruled out, except in the unlikely case of an extreme Galactic magnetic field with strength >10 ?G. Therefore, the fast rising proton contribution suggested by KASCADE-Grande data between 1017 eV and 1018 eV should be of extragalactic origin. In case heavy nuclei dominate the flux at E > 1018 eV, the transition energy can be close to the ankle, if Galactic cosmic rays are produced by sufficiently frequent transients as e.g. magnetars.

Giacinti, G.; Kachelrie, M.; Semikoz, D. V.; Sigl, G.

2013-06-01

326

High-Energy Cosmic Ray Event Data from the Pierre Auger Cosmic Ray Observatory  

DOE Data Explorer

The Pierre Auger Cosmic Ray Observatory in Mendoza, Argentina is the result of an international collaboration funded by 15 countries and many different organizations. Its mission is to capture high-energy cosmic ray events or air showers for research into their origin and nature. The Pierre Auger Collaboration agreed to make 1% of its data available to the public. The Public Event Explorer is a search tool that allows users to browse or search for and display figures and data plots of events collected since 2004. The repository is updated daily, and, as of June, 2014, makes more than 35,000 events publicly available. The energy of a cosmic ray is measured in Exa electron volts or EeV. These event displays can be browsed in order of their energy level from 0.1 to 41.1 EeV. Each event has an individual identification number.

The event displays provide station data, cosmic ray incoming direction, various energy measurements, plots, vector-based images, and an ASCII data file.

327

28th International Cosmic Ray Conference 4041 Long-Term Cosmic Ray Intensities: Physical Reconstruc-  

E-print Network

on the interplanetary magnetic field strength B because of a stronger scattering of cosmic ray particles in an enhanced magnetic field [19],[26]. On the other hand, the open solar magnetic flux is by definition proportional. (2000) have recently calculated the open solar magnetic flux for the last 400 years from sunspot data

Usoskin, Ilya G.

328

Underground cosmic-ray experiment EMMA  

NASA Astrophysics Data System (ADS)

EMMA (Experiment with MultiMuon Array) is a new approach to study the composition of cosmic rays at the knee region (1 - 10 PeV). The array will measure the multiplicity and lateral distribution of the high-energy muon component of an air shower and its arrival direction on an event-by-event basis. The array operates in the Pyhsalmi Mine, Finland, at a depth of 75 metres (or 210 m.w.e) corresponding to the cut-off energy of approximately 50 GeV for vertical muons. The data recording with a partial array has started and preliminary results of the first test runs are presented.

Kuusiniemi, P.; Bezrukov, L.; Enqvist, T.; Fynbo, H.; Inzhechik, L.; Joutsenvaara, J.; Kalliokoski, T.; Loo, K.; Lubsandorzhiev, B.; Monto, T.; Petkov, V.; Rih, T.; Sarkamo, J.; Slupecki, M.; Trzaska, W. H.; Virkajrvi, A.

2013-02-01

329

Fine structure in cosmic ray spectra  

NASA Astrophysics Data System (ADS)

The case is made for there being more 'structure' in the cosmic ray energy spectra than just the well-known knee at several PeV and the ankle at several EeV. Specifically, there seems to be a 'dip' or 'kink' at about 100 GeV/nucleon, a possible 'bump' at about 10 TeV, an 'iron peak' at 60 PeV and the possibility of further structure before the ankle is reached. The significance of the structures will be assessed.

Wolfendale, A. W.; Erlykin, A. D.

2013-02-01

330

The source abundances of galactic cosmic rays  

NASA Technical Reports Server (NTRS)

The galactic cosmic ray source abundances have been determined from two complete datasets, one at low and the other at high energy. For both exponential and truncated exponential pathlength distributions (PLD), the two sets of source abundances show significant differences for the primary elements, i.e., the Fe/O ratio. An energy dependent PLD reduces but does not eliminate the discrepancy, and this may indicate an energy dependence in the source composition. New source abundances for Na, P, Cl, Ca, and Mn are derived.

Dwyer, R. D.; Garcia-Munoz, M.; Guzik, T. G.; Meyer, P.; Simpson, J. A.; Wefel, J. P.

1982-01-01

331

Nonextensive thermal sources of cosmic rays?  

E-print Network

The energy spectrum of cosmic rays (CR) exhibits power-like behavior with a very characteristic "knee" structure. We consider a possibility that such a spectrum could be generated by some specific nonstatistical temperature fluctuations in the source of CR with the "knee" structure reflecting an abrupt change of the pattern of such fluctuations. This would result in a generalized nonextensive statistical model for the production of CR. The possible physical mechanisms leading to these effects are discussed together with the resulting chemical composition of the CR, which follows the experimentally observed abundance of nuclei.

Grzegorz Wilk; Zbigniew Wlodarczyk

2009-04-03

332

The Cosmic-Ray Isotope Spectrometer for the Advanced Composition Explorer  

Microsoft Academic Search

The Cosmic-Ray Isotope Spectrometer is designed to cover the highest decade of the Advanced Composition Explorer's energy\\u000a interval, from ?50 to ?500 MeV nucl?1, with isotopic resolution for elements from Z?2 to Z?30. The nuclei detected in this\\u000a energy interval are predominantly cosmic rays originating in our Galaxy. This sample of galactic matter can be used to investigate\\u000a the nucleosynthesis

E. C. Stone; C. M. S. Cohen; W. R. Cook; A. C. Cummings; B. Gauld; B. Kecman; R. A. Leske; R. A. Mewaldt; M. R. Thayer; B. L. Dougherty; R. L. Grumm; B. D. Milliken; R. G. Radocinski; M. E. Wiedenbeck; E. R. Christian; S. Shuman; H. Trexel; T. T. von Rosenvinge; W. R. Binns; D. J. Crary; P. Dowkontt; J. Epstein; P. L. Hink; J. Klarmann; M. Lijowski; M. A. Olevitch

1998-01-01

333

32ND INTERNATIONAL COSMIC RAY CONFERENCE, BEIJING 2011 Numerical model of cosmic ray induced ionization in the atmosphere CRAC:CRII  

E-print Network

32ND INTERNATIONAL COSMIC RAY CONFERENCE, BEIJING 2011 Numerical model of cosmic ray induced.Peterersburg, Russia 3 St. Petersburg State University, Russia ilya.usoskin@oulu.fi Abstract: Cosmic rays form the main cascade initiated by cosmic rays in the atmosphere. Here we present a new version of the CRAC:CRII model

Usoskin, Ilya G.

334

Cosmic Ray Nuclei in the Fermi-LAT ACD  

NASA Astrophysics Data System (ADS)

The Anti-Coincidence Detector (ACD) of the Fermi Large Area Telescope (LAT) serves to identify charged particles, which cross the LAT at a rate orders of magnitude higher than that of the gamma-ray signal. We have developed a method that uses cosmic-ray nuclei, Z > 3, as a calibration source to improve charge resolution of the light deposit measurement in the ACD at high light levels. Improving the charge resolution of the ACD gives the LAT an additional tool for cosmic-ray nuclei charge discrimination and therefore enhances the LAT's capability for analysis of cosmic-ray nuclei. In this analysis, we are able to distinguish eight cosmic-ray nuclei: boron, carbon, nitrogen, oxygen, neon, magnesium, silicon and iron in the LAT ACD's data. We present the results of our method, and demonstrate improved charge resolution for cosmic-ray nuclei in the ACD.

Green, David; Hays, E. A.; Brandt, T. J.

2014-01-01

335

Anomalous Cosmic Ray Production in the Heliosheath Jacob Chamoun, Prof. James F. Drake, Dr. Marc Swisdak  

E-print Network

Anomalous Cosmic Ray Production in the Heliosheath Jacob Chamoun, Prof. James F. Drake, Dr. Marc Swisdak Introduction · Anomalous cosmic rays (ACRs) are the highest energy cosmic rays produced within

Anlage, Steven

336

Extragalactic cosmic rays and their signatures  

E-print Network

The signatures of UHE proton propagation through CMB are pair-production dip and GZK cutoff. The visible manifestations of these spectral features are ankle, beginning of GZK cutoff in the differential spectrum and E_{1/2} in integral spectrum. Observed in all experiments, the ankle is usually interpreted as transition from galactic to extragalactic cosmic rays. Using the mass composition measured by HiRes, Telescope Array (TA) and Auger detectors at energy (1-3) EeV, calculated anisotropy of galactic cosmic rays at these energies, and the elongation curves we strongly argue against the interpretation of the ankle given above. The transition must occur at lower energy, most probably at the second knee as the dip model predicts. The other prediction of this model, the shape of the dip, is well confirmed by HiRes, TA, AGASA and Yakutsk detectors, and, after recalibration of energies, by Auger detector. Predicted beginning of GZK cutoff and E_{1/2} agree well with HiRes and TA data. However, directly measured ma...

Berezinsky, V

2014-01-01

337

Cosmic Rays in Clusters of Galaxies  

E-print Network

We argue that clusters of galaxies have an intergalactic medium, which is permeated by strong magnetic fields and also has a contribution of pressure from cosmic rays. These two components of total pressure are probably highly time dependent, and range probably between 1/10 of the gas pressure up to equipartition between gas pressure and the sum of the two other components. Radio galaxies are likely to provide the main source for both magnetic fields and cosmic rays. In this concept it becomes easy to understand the occasional mismatch between the total mass inferred from the assumption of hydrostatic equilibrium derived purely from gas, and the total mass derived from lensing data. We also suggest that the structure and topology of the magnetic field may be highly inhomogeneous - at least over a certain range of scales, and may contain long twisted filaments of strong magnetic fields, as on the Sun. The analogy with the interstellar medium may be fruitful to explore further, where we do not know where magnet...

Biermann, P L; Kang, H; Lee, H; Ryu, D; Biermann, Peter L.; En{\\ss}lin, Torsten A.; Kang, Hyesung; Lee, Hyesook; Ryu, Dongsu

2002-01-01

338

X-ray Production By Cosmic Muons  

NASA Astrophysics Data System (ADS)

Muons have a small cross section for interactions and high energy, so they are very penetrating and give the significant contribution to the gamma spectra of Ge detectors, even in deep underground laboratories. One of the muon interaction effects with material is X-rays production. Having in mind that gold is often used as a detectors component, in this paper the production of X-rays in gold sample is analyzed by using an coincidence system based on plastic scintillation detector and Ge detector. The Au disc-shaped sample with mass of 40.6 g, radius 3.34 cm and 0.06 cm thickness was inside 12 cm thick lead shield of extended range HPGe detector. The plastic detector of 0.5 0.5 0.05 m dimensions was placed above the lead shield at the distance of 32 cm from detector endcap. The producing rate of K? rays per Au mass unit from coincidence gamma spectrum is determined as R ~7.1 10-4 g-1s-1. Taking in account the measured muon flux of ?=54 s-1m-2, the muon cross section ?K?~ 43 Barn, for Au K? X-rays production is calculated. Also, the cross sections of X-ray production by cosmic muons in lead and tungsten are measured. Unexpectedly, the results obtained did not reveal Z dependence in the Z= 74-82 region.

Mrdja, D.; Bikit, I.; Ani?in, I.; Veskovi?, M.; Forkapi?, S.

2007-04-01

339

Ultrahigh Energy Cosmic Rays: Old Physics or New Physics?  

NASA Technical Reports Server (NTRS)

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).

Stecker, F. W.

2004-01-01

340

Cosmic ray particle dosimetry and trajectory tracing. [cosmic ray track analysis for Apollo 17 BIOCORE  

NASA Technical Reports Server (NTRS)

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.

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

1975-01-01

341

Direct Measurements, Acceleration and Propagation of Cosmic Rays  

E-print Network

This paper summarizes highlights of the OG1 session of the 30th International Cosmic Ray Conference, held in Merida (Yucatan, Mexico). The subsessions (OG1.1, OG1.2, OG1.3, OG1.4 and OG1.5) summarized here were mainly devoted to direct measurements, acceleration and propagation of cosmic rays.

Pasquale Blasi

2008-01-29

342

Elemental composition, isotopes, electrons and positrons in cosmic rays  

NASA Technical Reports Server (NTRS)

Papers presented at the 16th International Cosmic Ray Conference, Kyoto, Japan, dealing with the composition of cosmic rays are reviewed. Particular interest is given to data having bearing on nucleosynthesis sites, supernovae, gamma-process, comparison with solar system composition, multiplicity of sources, and the energy dependence of composition.

Balasubrahmanyan, V. K.

1979-01-01

343

Very High Energy Cosmic Rays and Their Interactions  

E-print Network

The investigation of high energy cosmic rays and their interactions is a very active field of research. This article summarizes the progress made during the last years as reflected by the contributions to the XIII International Symposium on Very High Energy Cosmic Ray Interactions held in Pylos, Greece.

Ralph Engel

2005-04-15

344

Early developments: Particle physics aspects of cosmic rays  

NASA Astrophysics Data System (ADS)

Cosmic rays is the birthplace of elementary particle physics. The 1936 Nobel prize was shared between Victor Hess and Carl Anderson. Anderson discovered the positron in a cloud chamber. The positron was predicted by Dirac several years earlier. In subsequent cloud chamber investigations Anderson and Neddermeyer saw the muon, which for some time was considered to be a candidate for the Yukawa particle responsible for nuclear binding. Measurements with nuclear emulsions by Lattes, Powell, Occhialini and Muirhead clarified the situation by the discovery of the charged pions in cosmic rays. The cloud chamber continued to be a powerful instrument in cosmic ray studies. Rochester and Butler found V's, which turned out to be shortlived neutral kaons decaying into a pair of charged pions. Also ?'s, ?'s, and ?'s were found in cosmic rays. But after that accelerators and storage rings took over. The unexpected renaissance of cosmic rays started with the search for solar neutrinos and the observation of the supernova 1987A. Cosmic ray neutrino results were best explained by the assumption of neutrino oscillations opening a view beyond the standard model of elementary particles. After 100 years of cosmic ray research we are again at the beginning of a new era, and cosmic rays may contribute to solve the many open questions, like dark matter and dark energy, by providing energies well beyond those of accelerators.

Grupen, Claus

2014-01-01

345

WORLD-WIDE COSMIC-RAY VARIATIONS, 19371952  

Microsoft Academic Search

Annual means from continuous registration of cosmic-ray ionizktion at four stations from 1937 to 1952 show a variation of nearly four per cent, which is similar at all stations and which is negatively correlated with sunspot numbers. This variation in cosmic-ray intensity is quite similar for the annual means of all days, international magnetic quiet days, and international magnetic disturbed

Scott E. Forbush

1954-01-01

346

The acceleration of cosmic rays by shock waves  

Microsoft Academic Search

The direct transfer of energy to cosmic rays from supersonic motions of the background medium via shock waves, by means of an efficient first order Fermi mechanism, is considered. The acceleration of cosmic rays by shock waves is most effective in the dilute and hot, 1,000,000-K component of the interstellar medium. There is no limit to the energy that can

W. I. Axford

1981-01-01

347

The effect of sea level cosmic rays on electronic devices  

Microsoft Academic Search

The evaluation of the effects of cosmic rays on computer memories and its application to typical memory devices will be discussed. Conclusions indicate that cosmic ray nucleons and muons could have a significant effect on the next generation of computer memory circuitry. Error rates increase rapidly with altitude, offering the potential of accelerated testing to make electronic equipment less sensitive

J. Ziegler; W. Lanford

1980-01-01

348

Cosmic-ray electron signatures of dark matter Martin Pohl*  

E-print Network

Cosmic-ray electron signatures of dark matter Martin Pohl* Department of Physics and Astronomy) There is evidence for an excess in cosmic-ray electrons at about 500 GeVenergy, that may be related to dark-matter spectrum, similar to that observed. On the other hand, if electron production by dark matter

Pohl, Martin Karl Wilhelm

349

Using the information of cosmic rays to predict influence epidemic  

Microsoft Academic Search

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

Z. D. Yu

1985-01-01

350

On-board detection and removal of cosmic ray and solar energetic particle signatures for the Solar Orbiter-METIS coronagraph  

NASA Astrophysics Data System (ADS)

METIS is part of the science payload of Solar Orbiter. It is a coronagraph designed to obtain images of the outer solar corona both in the visible 580-640 nm band and in the UV, in a narrow band centered around the hydrogen Lyman-? line. We describe the main features of the procedures to remove signatures due to cosmic rays (CRs) and to solar energetic particles (SEPs) comparing them with alternatives in other contexts and in other solar coronagraphic missions. Our analysis starts from a realistic assessment of the radiation environment where the instrument is expected to operate, which is characteristic of the interplanetary space of the inner solar system, but quite unusual for most solar missions.

Andretta, V.; Bemporad, A.; Focardi, M.; Grimani, C.; Landini, F.; Pancrazzi, M.; Sasso, C.; Spadaro, D.; Straus, T.; Uslenghi, M. C.; Antonucci, E.; Fineschi, S.; Naletto, G.; Nicolini, G.; Nicolosi, P.; Romoli, M.

2014-07-01

351

A search for correlations of TeV gamma-rays with ultra-high energy cosmic rays  

E-print Network

A search was conducted for TeV gamma-rays emitted from the direction of the ultra-high energy cosmic ray detected by the Fly's Eye Experiment with E ~ 3 x 10**20 eV. No enhancement was found at a level of 10**-10 gamma/cm**2-sec for E>350 GeV. This upper limit is consistent with theoretical estimates based on topological defects as sources of UHE cosmic rays. An upper limit was also set for the flux of TeV gamma rays from 3C147, the most prominent AGN in the error box.

C. W. Akerlof; S. Biller; P. Boyle; J. Buckley; D. A. Carter-Lewis; M. Catanese; M. F. Cawley; V. Connaughton; D. J. Fegan; J. Finley; J. Gaidos; A. M. Hillas; F. Krennrich; R. C. Lamb; R. Lessard; J. McEnery; G. Mohanty; N. A. Porter; J. Quinn; A. Rodgers; H. J. Rose; F. Samuelson; M. S. Schubnell; G. Sembroski; R. Srinivasan; T. C. Weekes; J. Zweerink; .

1997-06-12

352

A search for point sources of cosmic-ray muons using the MACRO detector  

SciTech Connect

A search is described for small-scale anisotropies in the cosmic-ray muon flux above 1 TeV, using the Monopole Astrophysics and Cosmic Ray Observatory (MACRO). From February 28 to May 30, 1989, MACRO detector collected data during its maiden run. Using these data, a search of the entire sky visible to MACRO was performed in an effort to find a small-scale flux of cosmic-ray muons. Results indicate that no small-scale anisotropies in the cosmic-ray muon flux exist {ge} 5.8 {times} 10{sup {minus}12} cm{sup {minus}2}s{sup {minus}1} down to 3 {times} 10{sup {minus}3} sr. Periodic effects in the muon flux were searched for in two cases: Cygnus X-3 and Hercules X-1. These two x-ray eclipsing binary stars were detected in TeV and PeV {gamma}-rays by air-shower experiments. Observations suggests that other high-energy particles, such as cosmic-ray primaries, may be produced in x-ray binary stars. Cygnus X-4 in particular may be a source of cosmic-ray primary particles. By observing muons presumably produced by atmospheric interactions, it may be possible to determine if systems such as Cygnus X-3 are indeed cosmic-ray accelerators. Two experiments claim to have observed time dependent muon excesses pointing back to Cygnus X-3. These findings suggest that no periodic flux of cosmic-ray muons from Cygnus X-3 or Hercules X-1 exists to {ge} 3 {times} 10{sup {minus}12} cm{sup {minus}2}s{sup {minus}1} over the time period of MACRO's maiden run.

Petrakis, J.P.

1990-01-01

353

30TH INTERNATIONAL COSMIC RAY CONFERENCE PoGOLite: a balloon-borne soft gamma-ray polarimeter  

E-print Network

30TH INTERNATIONAL COSMIC RAY CONFERENCE PoGOLite: a balloon-borne soft gamma-ray polarimeter M can detect 10% polarization of a 200 mCrab source in one 6 hour balloon observation. In flight in the strongly magnetized neutron star surface, respectively. Future goals include a long duration balloon flight

Haviland, David

354

Non-thermal radiation from molecular clouds illuminated by cosmic rays from nearby supernova remnants  

E-print Network

Molecular clouds are expected to emit non-thermal radiation due to cosmic ray interactions in the dense magnetized gas. Such emission is amplified if a cloud is located close to an accelerator of cosmic rays and if cosmic rays can leave the accelerator and diffusively reach the cloud. We consider the situation in which a molecular cloud is located in the proximity of a supernova remnant which is accelerating cosmic rays and gradually releasing them into the interstellar medium. We calculate the multiwavelength spectrum from radio to gamma rays which emerges from the cloud as the result of cosmic ray interactions. The total energy output is dominated by the gamma ray emission, which can exceed the emission from other bands by an order of magnitude or more. This suggests that some of the unidentified TeV sources detected so far, with no obvious or very weak counterpart in other wavelengths, might be associated with clouds illuminated by cosmic rays coming from a nearby source.

Stefano Gabici; Sabrina Casanova; Felix A. Aharonian

2008-09-30

355

The cosmic ray luminosity of the nearby active galactic nuclei  

E-print Network

The pointing directions of extensive air showers observed at the Pierre Auger Observatory were fitted within 3.1 degree with positions of the nearby active galactic nuclei from the Veron-Cetty and P. Veron catalog. The cosmic ray luminosity of the active galactic nuclei which happened to be a source of the particular cosmic ray event constitutes a fraction ~0.0001 of the optical one if only cosmic ray particles with energies above 60 EeV are produced. If produced cosmic ray particles have a spectrum dE/E^3 up to ~100 GeV then the cosmic ray luminosity would be much higher than the optical one of the active galactic nuclei.

L. G. Dedenko; D. A. Podgrudkov; T. M. Roganova; G. F. Fedorova

2008-04-29

356

Terrestrial Effects of High Energy Cosmic Rays  

NASA Astrophysics Data System (ADS)

On geological timescales, the Earth is likely to be exposed to an increased 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. Increased ionization could lead to changes in atmospheric chemistry, resulting in ozone depletion. This could increase the flux of solar UVB radiation at the surface, which is potentially harmful to living organisms. Increased ionization affects the global electrical circuit can could possibly enhance the low-altitude cloud formation rate. Secondary particles such as muons and thermal neutrons produced as a result of nuclear interactions are able to reach the ground, enhancing the biological radiation dose. The muon flux dominates radiation dose from cosmic rays causing DNA damage and increase in the mutation rates, which can have serious biological implications for terrestrial and sub-terrestrial life. This radiation dose is an important constraint on the habitability of a planet. Using CORSIKA, we perform massive computer simulations and construct lookup tables from 10 GeV - 1 PeV primaries (1 PeV - 0.1 ZeV in progress), which can be used to quantify these effects. These tables are freely available to the community and can be used for other studies, not necessarily relevant to Astrobiology. We use these tables to study the terrestrial implications of galactic shock generated by the infall of our galaxy toward the Virgo cluster. This could be a possible mechanism explaining the observed periodicity in biodiversity in paleobiology databases.

Atri, Dimitra

2011-01-01

357

The isotopic composition of cosmic-ray beryllium and its implication for the cosmic ray's age  

NASA Technical Reports Server (NTRS)

We report a new measurement of the cosmic-ray isotopic composition of beryllium in the low-energy range from 35 to 113 MeV per nucleon. This measurement was made using the High Energy Telescope of the CRS experiment on the Voyager 1 and 2 spacecraft during the time period from 1977 to 1991. In this overall time period of 14 years the average solar modulation level was about 500 MV. The cosmic-ray beryllium isotopes were completely separated with an average mass resolution sigma of 0.185 amu. The isotope fractions of Be-7, Be-9, and Be-10 obtained are 52.4 +/- 2.9%, 43.3 +/- 3.7%, and 4.3 +/- 1.5%, respectively. The measured cosmic-ray abundances of Be-7 and Be-9 are found to be in agreement with calculations based on standard Leaky-Box model for the interstellar propagation of cosmic-ray nuclei using the recent cross sections of the New Mexico-Saclay collaboration. From our observed ratio Be-10/Be = 4.3 +/- 1.5% we deduce an average interstellar density of about 0.28 (+0.14, -0.11) atoms/cu cm, and acosmic-ray lifetime for escape of 27 (+19, -9) x 10(exp 6) years. The surviving fraction of Be-10 is found to be 0.19 +/- 0.07. Modifications to the conclusions of the Leaky-Box model when a diffusion + convection halo model for propagation is used are also considered.

Lukasiak, A.; Ferrando, P.; Mcdonald, F. B.; Webber, W. R.

1994-01-01

358

Clusters of Galaxies Shock Waves and Cosmic Rays  

E-print Network

Recent observations of galaxy clusters in radio and X-ray indicate that cosmic rays and magnetic fields may be energetically important in the intracluster medium. According to the estimates based on theses observational studies, the combined pressure of these two components of the intracluster medium may range between $10% \\sim 100 %$ of gas pressure, although their total energy is probably time dependent. Hence, these non-thermal components may have influenced the formation and evolution of cosmic structures, and may provide unique and vital diagnostic information through various radiations emitted via their interactions with surrounding matter and cosmic background photons. We suggest that shock waves associated with cosmic structures, along with individual sources such as active galactic nuclei and radio galaxies, supply the cosmic rays and magnetic fields to the intracluster medium and to surrounding large scale structures. In order to study 1) the properties of cosmic shock waves emerging during the larg...

Ryu, D; Ryu, Dongsu; Kang, Hyesung

2002-01-01

359

Transition from galactic to extragalactic cosmic rays  

NASA Astrophysics Data System (ADS)

The study of the transition between galactic and extragalactic cosmic rays can shed more light on the end of the galactic cosmic rays spectrum and the beginning of the extragalactic one. Three models of transition are discussed: ankle, dip and mixed composition models. All these models describe the transition as an intersection of a steep galactic component with a flat extragalactic one. Severe bounds on these models are provided by the Standard Model of galactic cosmic rays according to which the maximum acceleration energy for Iron nuclei is of the order of EFemax?11017eV. In the ankle model the transition is assumed at the ankle, a flat feature in the all particle spectrum which observationally starts at energy Ea(3-4)1018eV. This model needs a new high energy galactic component with maximum energy about two orders of magnitude above that of the Standard Model. The origin of such component is discussed. As observations are concerned there are two signatures of the transition: change of energy spectra and mass composition. In all models a heavy galactic component is changed at the transition to a lighter or proton component. As a result the ankle model predicts a galactic Iron component at E<51018eV, while both HiRes and Auger data show that at (2-5)1018eV primaries are protons, or at least light nuclei. In the dip model the transition occurs at the second knee observed at energy (4-7)1017eV and is characterized by a sharp change of mass composition from galactic Iron to extragalactic protons. The ankle in this model appears automatically as a part of the e+e- pair-production dip. The mixed composition model describes transition at E31018eV with mass composition changing from the galactic Iron to extragalactic mixed composition of different nuclei. In most mixed composition models the spectrum is proton-dominated and it better fits HiRes than Auger data. The latter show a steadily heavier mass composition with increasing energy, and we discuss the models which explain it.

Aloisio, R.; Berezinsky, V.; Gazizov, A.

2012-12-01

360

Cosmic ray environment model for Earth orbit  

NASA Technical Reports Server (NTRS)

A set of computer codes, which include the effects of the Earth's magnetic field, used to predict the cosmic ray environment (atomic numbers 1 through 28) for a spacecraft in a near-Earth orbit is described. A simple transport analysis is used to approximate the environment at the center of a spherical shield of arbitrary thickness. The final output is in a form (a Heinrich Curve) which has immediate applications for single event upset rate predictions. The codes will culate the time average environment for an arbitrary number (fractional or whole) of circular orbits. The computer codes were run for some selected orbits and the results, which can be useful for quick estimates of single event upset rates, are given. The codes were listed in the language HPL, which is appropriate or a Hewlett Packard 9825B desk top computer. Extensive documentation of the codes is available from COSMIC, except where explanations have been deferred to references where extensive documentation can be found. Some qualitative aspects of the effects of mass and magnetic shielding are also discussed.

Edmonds, L.

1985-01-01

361

Cosmic ray simulator: A versatile apparatus for quantitative studies on the interaction of cosmic rays with frozen solids by on line and in sift  

E-print Network

Cosmic ray simulator: A versatile apparatus for quantitative studies on the interaction of cosmic) The cosmic ray simulator consists of a 50 L'cylindrical stainless steel chamber. A rotable cold finger milled spectrometer (FTIR) in an absorption-reflection mode at 62.5". For the first time, a cosmic ray simulator

Kaiser, Ralf I.

362

A search for microwave emission from cosmic ray air showers  

NASA Astrophysics Data System (ADS)

At the highest energies, the sources of cosmic rays should be among the most powerful extragalactic accelerators. Large observatories have revealed a flux suppression above a few 1019 eV, similar to the expected effect of the interaction of ultrahigh energy cosmic rays (UHECR) with the cosmic microwave background. The Pierre Auger Observatory has measured the largest sample of cosmic ray induced extensive air showers (EAS) at the highest energies leading to a precise measurement of the energy spectrum, hints of spatial anisotropy, and a surprising change in the chemical composition at the highest energies. To answer the question of the origin of UHECRs a larger sample of high quality data will be required to reach a statistically significant result. One of the possible techniques suggested to achieve this much larger data sample, in a cost effective way, is ultra-wide field of view microwave telescopes which would operate in an analogous way to the already successful fluorescence detection (FD) technique. Detecting EAS in microwaves could be done with 100% duty cycle and essentially no atmospheric effects. This presents many advantages over the FD which has a 10% duty cycle and requires extensive atmospheric monitoring for calibration. We have pursued both prototype detector designs and improved laboratory measurements, the results of which are reported herein, and published in (Alvarez-Muniz et al., 2013; Alvarez-Muniz et al., 2012a; Williams et al., 2013; Alvarez-Muniz et al., 2013). The Microwave Detection of Air Showers (MIDAS) experiment is the first ultra-wide field of view imaging telescope deployed to detect isotropic microwave emission from EAS. With 61 days of livetime data operating on the University of Chicago campus we were able to set new limits on isotropic microwave emission from extensive air showers. The new limits rule out current laboratory air plasma measurements (Gorham et al., 2008) by more than five sigma. The MIDAS experiment continues to take data installed in Argentina, operating in coincidence with the Pierre Auger Observatory. Using the first 70 days of livetime data combined with a sample of EAS events from the Auger surface detector we are able to set a preliminary limit which is even more stringent than that set with the Chicago data set. Test beam efforts performed at Argonne National Lab, The Microwave Air Yield Beam Experiment (MAYBE), have successfully measured a microwave signal which exhibits linear scaling with energy deposit in a frequency range of 1 GHz to 15 GHz. This measurement has produced strong upper limits on the isotropic emission of microwaves from air plasmas.

Williams, Christopher Lee

363

Detection of gamma rays from a starburst galaxy.  

PubMed

Starburst galaxies exhibit in their central regions a highly increased rate of supernovae, the remnants of which are thought to accelerate energetic cosmic rays up to energies of approximately 10(15) electron volts. We report the detection of gamma rays--tracers of such cosmic rays--from the starburst galaxy NGC 253 using the High Energy Stereoscopic System (H.E.S.S.) array of imaging atmospheric Cherenkov telescopes. The gamma-ray flux above 220 billion electron volts is F = (5.5 +/- 1.0(stat) +/- 2.8(sys)) x 10(-13) cm(-2) s(-1), implying a cosmic-ray density about three orders of magnitude larger than that in the center of the Milky Way. The fraction of cosmic-ray energy channeled into gamma rays in this starburst environment is five times as large as that in our Galaxy. PMID:19779150

Acero, F; Aharonian, F; Akhperjanian, A G; Anton, G; Barres de Almeida, U; Bazer-Bachi, A R; Becherini, Y; Behera, B; Bernlhr, K; Bochow, A; Boisson, C; Bolmont, J; Borrel, V; Brucker, J; Brun, F; Brun, P; Bhler, R; Bulik, T; Bsching, I; Boutelier, T; Chadwick, P M; Charbonnier, A; Chaves, R C G; Cheesebrough, A; Chounet, L-M; Clapson, A C; Coignet, G; Dalton, M; Daniel, M K; Davids, I D; Degrange, B; Deil, C; Dickinson, H J; Djannati-Ata, A; Domainko, W; Drury, L O'C; Dubois, F; Dubus, G; Dyks, J; Dyrda, M; Egberts, K; Emmanoulopoulos, D; Espigat, P; Farnier, C; Fegan, S; Feinstein, F; Fiasson, A; Frster, A; Fontaine, G; Fssling, M; Gabici, S; Gallant, Y A; Grard, L; Gerbig, D; Giebels, B; Glicenstein, J F; Glck, B; Goret, P; Gring, D; Hauser, D; Hauser, M; Heinz, S; Heinzelmann, G; Henri, G; Hermann, G; Hinton, J A; Hoffmann, A; Hofmann, W; Hofverberg, P; Hoppe, S; Horns, D; Jacholkowska, A; de Jager, O C; Jahn, C; Jung, I; Katarzy?ski, K; Katz, U; Kaufmann, S; Kerschhaggl, M; Khangulyan, D; Khlifi, B; Keogh, D; Klochkov, D; Klu?niak, W; Kneiske, T; Komin, Nu; Kosack, K; Kossakowski, R; Lamanna, G; Lenain, J-P; Lohse, T; Marandon, V; Martineau-Huynh, O; Marcowith, A; Masbou, J; Maurin, D; McComb, T J L; Medina, M C; Mhault, J; Moderski, R; Moulin, E; Naumann-Godo, M; de Naurois, M; Nedbal, D; Nekrassov, D; Nicholas, B; Niemiec, J; Nolan, S J; Ohm, S; Olive, J-F; de Oa Wilhelmi, E; Orford, K J; Ostrowski, M; Panter, M; Paz Arribas, M; Pedaletti, G; Pelletier, G; Petrucci, P-O; Pita, S; Phlhofer, G; Punch, M; Quirrenbach, A; Raubenheimer, B C; Raue, M; Rayner, S M; Reimer, O; Renaud, M; Rieger, F; Ripken, J; Rob, L; Rosier-Lees, S; Rowell, G; Rudak, B; Rulten, C B; Ruppel, J; Sahakian, V; Santangelo, A; Schlickeiser, R; Schck, F M; Schwanke, U; Schwarzburg, S; Schwemmer, S; Shalchi, A; Sikora, M; Skilton, J L; Sol, H; Stawarz, ?; Steenkamp, R; Stegmann, C; Stinzing, F; Superina, G; Szostek, A; Tam, P H; Tavernet, J-P; Terrier, R; Tibolla, O; Tluczykont, M; van Eldik, C; Vasileiadis, G; Venter, C; Venter, L; Vialle, J P; Vincent, P; Vivier, M; Vlk, H J; Volpe, F; Wagner, S J; Ward, M; Zdziarski, A A; Zech, A

2009-11-20

364

Detection of Gamma Rays from a Starburst Galaxy  

NASA Astrophysics Data System (ADS)

Starburst galaxies exhibit in their central regions a highly increased rate of supernovae, the remnants of which are thought to accelerate energetic cosmic rays up to energies of ~1015 electron volts. We report the detection of gamma raystracers of such cosmic raysfrom the starburst galaxy NGC 253 using the High Energy Stereoscopic System (H.E.S.S.) array of imaging atmospheric Cherenkov telescopes. The gamma-ray flux above 220 billion electron volts is F = (5.5 1.0stat 2.8sys) 10-13 cm-2 s-1, implying a cosmic-ray density about three orders of magnitude larger than that in the center of the Milky Way. The fraction of cosmic-ray energy channeled into gamma rays in this starburst environment is five times as large as that in our Galaxy.

Acero, F.; Aharonian, F.; Akhperjanian, A. G.; Anton, G.; Barres de Almeida, U.; Bazer-Bachi, A. R.; Becherini, Y.; Behera, B.; Bernlhr, K.; Bochow, A.; Boisson, C.; Bolmont, J.; Borrel, V.; Brucker, J.; Brun, F.; Brun, P.; Bhler, R.; Bulik, T.; Bsching, I.; Boutelier, T.; Chadwick, P. M.; Charbonnier, A.; Chaves, R. C. G.; Cheesebrough, A.; Chounet, L.-M.; Clapson, A. C.; Coignet, G.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; Dickinson, H. J.; Djannati-Ata, A.; Domainko, W.; Drury, L. O.'C.; Dubois, F.; Dubus, G.; Dyks, J.; Dyrda, M.; Egberts, K.; Emmanoulopoulos, D.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fiasson, A.; Frster, A.; Fontaine, G.; Fling, M.; Gabici, S.; Gallant, Y. A.; Grard, L.; Gerbig, D.; Giebels, B.; Glicenstein, J. F.; Glck, B.; Goret, P.; Gring, D.; Hauser, D.; Hauser, M.; Heinz, S.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hinton, J. A.; Hoffmann, A.; Hofmann, W.; Hofverberg, P.; Hoppe, S.; Horns, D.; Jacholkowska, A.; de Jager, O. C.; Jahn, C.; Jung, I.; Katarzy?ski, K.; Katz, U.; Kaufmann, S.; Kerschhaggl, M.; Khangulyan, D.; Khlifi, B.; Keogh, D.; Klochkov, D.; Klu?niak, W.; Kneiske, T.; Komin, Nu.; Kosack, K.; Kossakowski, R.; Lamanna, G.; Lenain, J.-P.; Lohse, T.; Marandon, V.; Martineau-Huynh, O.; Marcowith, A.; Masbou, J.; Maurin, D.; McComb, T. J. L.; Medina, M. C.; Mhault, J.; Moderski, R.; Moulin, E.; Naumann-Godo, M.; de Naurois, M.; Nedbal, D.; Nekrassov, D.; Nicholas, B.; Niemiec, J.; Nolan, S. J.; Ohm, S.; Olive, J.-F.; Wilhelmi, E. de Oa; Orford, K. J.; Ostrowski, M.; Panter, M.; Arribas, M. Paz; Pedaletti, G.; Pelletier, G.; Petrucci, P.-O.; Pita, S.; Phlhofer, G.; Punch, M.; Quirrenbach, A.; Raubenheimer, B. C.; Raue, M.; Rayner, S. M.; Reimer, O.; Renaud, M.; Rieger, F.; Ripken, J.; Rob, L.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Ruppel, J.; Sahakian, V.; Santangelo, A.; Schlickeiser, R.; Schck, F. M.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Shalchi, A.; Sikora, M.; Skilton, J. L.; Sol, H.; Stawarz, ?.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Superina, G.; Szostek, A.; Tam, P. H.; Tavernet, J.-P.; Terrier, R.; Tibolla, O.; Tluczykont, M.; van Eldik, C.; Vasileiadis, G.; Venter, C.; Venter, L.; Vialle, J. P.; Vincent, P.; Vivier, M.; Vlk, H. J.; Volpe, F.; Wagner, S. J.; Ward, M.; Zdziarski, A. A.; Zech, A.

2009-11-01

365

Evidence for the Superbubble Origin of Galactic Cosmic Rays  

NASA Astrophysics Data System (ADS)

Measurements of the isotopic and elemental abundances of galactic cosmic rays from the Cosmic Ray Isotope Spectrometer (CRIS) aboard the NASA-ACE spacecraft, and elemental abundances from the balloon-borne Trans-Iron Galactic Element Recorder (TIGER) provide strong evidence that a large fraction of galactic cosmic rays originate and are accelerated in associations of massive stars (OB associations) and their associated superbubbles. Neon and iron isotopic abundances point to a superbubble origin in which the galactic cosmic rays (GCRs) come from material that is roughly a 20%-80% mix of OB association material and ordinary interstellar medium material (ISM). This assumption that GCRs come from such a mix instead of ordinary ISM results in greatly improved ordering of volatile and refractory GCR elemental abundances when plotted versus atomic mass. This strengthens the OB association-superbubble connection with cosmic ray origin. More recently, the LAT instrument aboard the Fermi spacecraft has identified distributed emission of gamma-rays from a "cocoon" identified with the Cygnus-X superbubble, indicating the acceleration of cosmic rays in the superbubble. These measurements and the implications for the OB-association/superbubble origin of galactic cosmic rays will be discussed. Principal funding for this research was from NASA under grants NNG05WC04G and NAG5-12929.

Binns, W.

2012-12-01

366

Low-energy cosmic ray protons from nuclear interactions of cosmic rays with the interstellar medium.  

NASA Technical Reports Server (NTRS)

The intensity of low-energy (less than 100 MeV) protons from nuclear interactions of higher-energy (above 100 MeV) cosmic rays with the interstellar medium is calculated. The resultant intensity in the 10- to 100-MeV range is larger by a factor of 3-5 than the observed proton intensity near earth. The calculated intensity from nuclear interactions constitutes a lower limit on the actual proton intensity in interstellar space.

Wang, H. T.

1973-01-01

367

Cosmic ray drift, shock wave acceleration, and the anomalous component of cosmic rays  

Microsoft Academic Search

A model of the anomalous component of the quiet-time cosmic ray flux is presented in which ex--interstellar neutral particles are accelerated continuously in the polar regions of the solar-wind termination shock and then drift into the equatorial regions of the inner heliosphere. The observed solar-cycle variations, radial gradient, and apparent latitude gradient of the anomalous component are a natural consequence

M. E. Pesses; J. R. Jokipii; D. Eichler

1981-01-01

368

Cosmic ray drift, shock wave acceleration and the anomalous component of cosmic rays  

NASA Technical Reports Server (NTRS)

A model of the anomalous component of the quiet-time cosmic ray flux is presented in which ex-interstellar neutral particles are accelerated continuously in the polar regions of the solar-wind termination shock, and then drift into the equatorial regions of the inner heliosphere. The observed solar-cycle variations, radial gradient, and apparent latitude gradient of the anomalous component are a natural consequence of this model.

Pesses, M. E.; Jokipii, J. R.; Eichler, D.

1981-01-01

369

Can Chandra resolve the remaining cosmic X-ray background?  

E-print Network

The deepest extragalactic X-ray observation, the 2 Ms Chandra Deep Field North (CDF-N), resolves ~80% of the total extragalactic cosmic X-ray background (CXB) in the 1-2 keV band. Recent work has shown that 70% of the remaining CXB flux is associated with sources detected by the Hubble Space Telescope (HST). This paper uses the existing CDF-N data to constrain the X-ray flux distribution of these X-ray undetected HST sources, by comparing the number of 0.5-2 keV X-ray counts at the HST positions to those expected for model flux distributions. In the simple case where all the undetected HST X-ray sources have the same 0.5-2 keV flux, the data are best fit by 1.5-3 counts per source in 2 Ms, compared to a detection limit (at 10% completeness) of 9 counts. Assuming a more realistic power-law logN-logS distribution [N(>S) S^-alpha], the data favor a relatively steep flux distribution, with alpha=1.1^+0.5_-0.3 (limits are 99% confidence). This slope is very similar to that previously found for faint normal and starburst galaxies in the CDF-N. These results suggest deeper Chandra observations will detect a new population of faint X-ray sources, but extremely deep exposures are needed to resolve the remainder of the soft CXB. In the most optimistic scenario, when the HST sources have the flattest allowed flux distribution and all the sources without HST counterparts are detected, observations 5 times more sensitive than the existing ones would resolve at most ~60% of the remaining soft CXB.

Ryan C. Hickox; Maxim Markevitch

2007-11-27

370

Cosmic Ray Propagation in Galactic Turbulence  

NASA Astrophysics Data System (ADS)

We revisit propagation of galactic cosmic rays (CRs) in light of recent advances in CR diffusion theory in realistic interstellar turbulence. We use a tested model of turbulence in which it has been shown that fast modes dominate scattering of CRs. As a result, propagation becomes inhomogeneous and environment dependent. By adopting the formalism of the nonlinear theory developed by Yan & Lazarian, we calculate the diffusion of CRs self-consistently from first principles. We assume a two-phase model for the Galaxy to account for different damping mechanisms of the fast modes, and we find that the energy dependence of the diffusion coefficient is mainly affected by medium properties. We show that it gives a correct framework to interpret some of the recent CR puzzles.

Evoli, Carmelo; Yan, Huirong

2014-02-01

371

The origin of galactic cosmic rays  

E-print Network

Initial discovery of CRs dates back to a century ago (1912). Their identification as particles rather than radiation dates to about 20 years later and in 20 more years also the first suggestion that they were associated with SNRs was in place. The basic mechanism behind their acceleration was suggested almost 40 years ago. Much work has been done since then to the aim of proving that both the acceleration mechanism and site are well understood, but no definite proof has been obtained: in spite of impressive progress of both theory and observations, the evidence in support of the commonly accepted interpretation is only circumstantial. In the following I will try to make the point on where we stand in terms of how our theories confront with data: I will review recent progress on the subject and try to point to avenues to pursue in order to gather new proofs, if not smoking gun evidence of the origin of Galactic Cosmic Rays.

Amato, Elena

2014-01-01

372

ATLAS RPC certification with cosmic rays  

NASA Astrophysics Data System (ADS)

Almost one-third of the 1116 resistive plate chamber (RPC) units installed in the ATLAS experiment was tested and certified at the Lecce Cosmic Ray Testing Facility. About half of these units belong to the same chamber typology named barrel outer small (BOS). This large and nearly homogeneous sample allowed to perform an extensive study of the detector behavior and characteristics. The intrinsic spread of the chamber parameters was extracted after correction for known pressure and temperature effects. A residual dependence on pressure and temperature has been found and empirically corrected. The distribution of gas gap and panel efficiencies, cluster sizes (CSs), single rates and dark currents versus the applied threshold and high voltage was measured. An optimal working point was defined for each gas volume and the distribution of all relevant parameters was studied at the average working point for different voltage threshold. This work shows that the single unit BOS ATLAS RPC meets the experiment requirements.

Bianco, M.; Chiodini, G.; Gorini, E.; Grancagnolo, F.; Perrino, R.; Primavera, M.; Spagnolo, S.

2009-05-01

373

TIROS-N Cosmic Ray study  

NASA Technical Reports Server (NTRS)

An experimental and analytical study was performed on the impact of galactic cosmic rays on the TIROS-N satellite memory in orbit. Comparisons were made of systems equipped with the Harris HMI-6508 1 x 1024 CMOS/bulk RAM and the RCA CDP-1821 1 x 1024 bit CMOS/SOS RAM. Based upon the experimental results, estimated bit error rates were determined. These were at least 8.0 bit errors/day for a 300 kilobit memory with the HMI-6508 and .014 bit errors/day with the CDF-1821. It was also estimated that the HMI-6508 latchup rate in orbit is at least two orders of magnitude less than the bit error rates; the CDP-1821 will not latchup.

Blandford, J. T., Jr.; Pickel, J. C.

1980-01-01

374

Cosmic Ray Acceleration at Relativistic Shocks  

E-print Network

Theoretical studies of cosmic ray particle acceleration in the first-order Fermi process at relativistic shocks are reviewed. At the beginning we discuss the acceleration processes acting at mildly relativistic shock waves. An essential role of oblique field configurations and field perturbations in forming the particle energy spectrum and changing the acceleration time scale is discussed. Then, we report on attempts to consider particle acceleration at ultra-relativistic shocks, often yielding an asymptotic spectral index sigma = 2.2 at large shock Lorentz factors. We explain why this result is limited to the cases of highly turbulent conditions near shocks. We conclude that our present knowledge of the acceleration processes acting at relativistic shocks is insufficient to allow for realistic modelling of the real shocks. The present review is a modified, extended and updated version of Ostrowski (1999).

Michal Ostrowski

2003-10-29

375

Galactic Cosmic Rays in the Outer Heliosphere  

NASA Technical Reports Server (NTRS)

We report a next generation model of galactic cosmic ray (GCR) transport in the three dimensional heliosphere. Our model is based on an accurate three-dimensional representation of the heliospheric interface. This representation is obtained by taking into account the interaction between partially ionized, magnetized plasma flows of the solar wind and the local interstellar medium. Our model reveals that after entering the heliosphere GCRs are stored in the heliosheath for several years. The preferred GCR entry locations are near the nose of the heliopause and at high latitudes. Low-energy (hundreds of MeV) galactic ions observed in the heliosheath have spent, on average, a longer time in the solar wind than those observed in the inner heliosphere, which would explain their cooled-off spectra at these energies. We also discuss radial gradients in the heliosheath and the implications for future Voyager observations

Florinski, V.; Washimi, H.; Pogorelov, N. V.; Adams, J. H.

2010-01-01

376

Cosmic Ray Compaction of Porous Interstellar Ices  

NASA Astrophysics Data System (ADS)

We studied the compaction of microporous vapor-deposited ice films under irradiation with different ions in the 80-400 keV energy range. We found that porosity decreases exponentially with irradiation fluence, with a mean compaction area per ion that scales linearly with the stopping power of the projectile S above a threshold St=4 eV -1. The experiments roughly follow a universal dependence of ion-induced compaction with restricted dose (eV molecule-1). This behavior can be used to extrapolate our results to conditions of the interstellar medium. Relating our results to ionization rates of interstellar H2, we estimate that porous ice mantles on grains in dense molecular clouds are compacted by cosmic rays in ~10-50 million years.

Raut, U.; Fam, M.; Loeffler, M. J.; Baragiola, R. A.

2008-11-01

377

Cosmic ray decreases and magnetic clouds  

NASA Technical Reports Server (NTRS)

Energetic particle data, obtained from IMP 8, in conjunction with solar wind field and plasma data at the times of reported magnetic clouds was studied. It is shown that magnetic clouds can cause a depression of the cosmic ray flux but high fields are required. A depression of 3 percent in a neutron monitor requires a field of about 25 nT. Such high fields are found only in a subset of coronal ejecta. The principal cause for Forbush decreases associated with energetic shocks is probably turbulence in the post-shock region although some shocks will be followed by an ejecta with a high field. Each event is different. The lower energy particles can help in identifying the dominant processes in individual events.

Cane, H. V.

1992-01-01

378

Early Cosmic Ray Research with Balloons  

NASA Astrophysics Data System (ADS)

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

Walter, Michael

2013-06-01

379

Transport and acceleration of anomalous cosmic rays  

NASA Astrophysics Data System (ADS)

Anomalous cosmic rays are produced from interstellar pickup ions by heliospheric plasma processes. The solar wind termination shock was believed to be the source of these high-energy ions before the Voyagers' shock encounter. Because ACR spectra were observed to be modulated at the shock, several different acceleration cites and mechanisms were proposed. These included termination shock locations not visited by the Voyagers, the inner helioshgeath, and regions near the heliopause. I will review and compare the current generation of ACR transport models, including an update on the Huntsville model. A need to accommodate a physically realistic geometry of the termination shock and heliosheath for ACR modeling is emphasized. I also discuss recent ACR flux decreases as a sign of Voyager's proximity to the heliopause.

Florinski, Vladimir; Senanayake, Udara

2012-07-01

380

Cosmic ray proton spectra at low rigidities  

NASA Technical Reports Server (NTRS)

The cosmic ray proton rigidity spectra have been investigated with data collected in the Low Energy Antiproton (LEAP) balloon flight experiment flown from Prince Albert, Canada in 1987. The LEAP apparatus was designed to measure antiprotons using a superconducting magnet spectrometer with ancillary scintillator, time-of-flight, and liquid Cherenkov detectors. After reaching float altitude the balloon drifted south and west to higher geomagnetic cutoffs. The effect of the changing geomagnetic cutoff on the observed spectra was observed during analysis of the proton data along the balloon trajectory. This is the first measurement of the primary and splash albedo spectra over a wide rigidity range (few hundred MV to about 100 GV) with a single instrument.

Seo, E. S.; Ormes, J. F.; Streitmatter, R. E.; Lloyd-Evans, J.; Jones, W. V.

1990-01-01

381

Cosmic Rays: The Second Knee and Beyond  

E-print Network

We conduct a review of experimental results on Ultra-High Energy Cosmic Rays (UHECR's) including measurements of the features of the spectrum, the composition of the primary particle flux and the search for anisotropy in event arrival direction. We find that while there is a general consensus on the features in the spectrum -- the Second Knee, the Ankle, and (to a lesser extent) the GZK Cutoff -- there is little consensus on the composition of the primaries that accompany these features. This lack of consensus on the composition makes interpretation of the agreed upon features problematic. There is also little direct evidence about potential sources of UHECRs, as early reports of arrival direction anisotropies have not been confirmed in independent measurements.

Douglas R Bergman; John W. Belz

2007-04-27

382

30TH INTERNATIONAL COSMIC RAY CONFERENCE Gamma-ray albedo of the moon  

E-print Network

30TH INTERNATIONAL COSMIC RAY CONFERENCE Gamma-ray albedo of the moon I. V. MOSKALENKO1,2 , T. A@stanford.edu Abstract: We use the GEANT4 Monte Carlo framework to calculate the -ray albedo of the Moon due to interactions of cosmic ray (CR) nuclei with moon rock. Our calculation of the albedo spectrum agrees

Moskalenko, Igor V.

383

Pulsar Wind Nebulae and Cosmic Rays: A Bedtime Story  

E-print Network

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

,

2014-01-01

384

Extragalactic cosmic rays and their signatures  

E-print Network

The signatures of UHE proton propagation through CMB are pair-production dip and GZK cutoff. The visible manifestations of these spectral features are ankle, beginning of GZK cutoff in the differential spectrum and E_{1/2} in integral spectrum. Observed in all experiments, the ankle is usually interpreted as transition from galactic to extragalactic cosmic rays. Using the mass composition measured by HiRes, Telescope Array (TA) and Auger detectors at energy (1-3) EeV, calculated anisotropy of galactic cosmic rays at these energies, and the elongation curves we strongly argue against the interpretation of the ankle given above. The transition must occur at lower energy, most probably at the second knee as the dip model predicts. The other prediction of this model, the shape of the dip, is well confirmed by HiRes, TA, AGASA and Yakutsk detectors, and, after recalibration of energies, by Auger detector. Predicted beginning of GZK cutoff and E_{1/2} agree well with HiRes and TA data. However, directly measured mass composition remains a puzzle. While HiRes and TA detectors observe the proton-dominated mass composition, as required by the dip model, the data of Auger detector strongly evidence for nuclei mass composition becoming steadily heavier at energy higher than 4 EeV and reaching Iron at energy about 35 EeV. The Auger-based scenario is consistent with another interpretation of the ankle at energy E_a=4 EeV as transition from extragalactic protons to extragalactic nuclei. The heavy- nuclei dominance at higher energies may be provided by low-energy of acceleration for protons E_{max} \\sim 4 EeV and rigidity-dependent E_{max}^A =Z E_{max}$ for nuclei. The highest energy suppression may be explained as nuclei-destroying cutoff.

V. Berezinsky

2013-04-20

385

Extragalactic cosmic rays and their signatures  

NASA Astrophysics Data System (ADS)

The signatures of UHE proton propagation through CMB radiation are pair-production dip and GZK cutoff. The visible manifestations of these two spectral features are ankle, which is intrinsic part of the dip, beginning of GZK cutoff in the differential spectrum and E in integral spectrum. Observed practically in all experiments since 1963, the ankle is usually interpreted as a feature caused by transition from galactic to extragalactic cosmic rays. Using the mass composition measured by HiRes, Telescope Array and Auger detectors at energy (1-3) EeV, calculated anisotropy of galactic cosmic rays at these energies, and the elongation curves we strongly argue against the interpretation of the ankle given above. The transition must occur at lower energy, most probably at the second knee as the dip model predicts. The other prediction of the dip model, the shape of the dip, is well confirmed by HiRes, Telescope Array (TA), AGASA and Yakutsk detectors, and, after recalibration of energies, by Auger detector. Predicted beginning of GZK cutoff and E agree well with HiRes and TA data. However, directly measured mass composition remains a puzzle. While HiRes and TA detectors observe the proton-dominated mass composition, as required by the dip model, the data of Auger detector strongly evidence for nuclei mass composition becoming progressively heavier at energy higher than 4 EeV and reaching Iron at energy about 35 EeV. The Auger-based scenario is consistent with another interpretation of the ankle at energy Ea?4 EeV as transition from extragalactic protons to extragalactic nuclei. The heavy-nuclei dominance at higher energies may be provided by low-energy of acceleration for protons Epmax?4 EeV and rigidity-dependent EAmax=ZEpmax for nuclei. The highest energy suppression may be explained as nuclei-photodisintegration cutoff.

Berezinsky, V.

2014-01-01

386

Cosmic Ray Statistics using LabVIEW  

NSDL National Science Digital Library

Counting statistics of cosmic rays is explored using a LabVIEW based computer program on a computer connected to a National Instruments data acquisition unit. The program collects the interval times between successive coincident pulses from a stack of plastic scintillator detectors. Analysis of the data set allows students to see the distribution of N-pulse intervals for various values of N; this is the Erlang distribution. With N = 1, the Erlang distribution is exponential with a characteristic time equal to mean count interval t. When N is increased, the distribution becomes peaked at Nt with a fractional width proportional to 1/?N. This is an instance of the central limit theorem. Students may also examine the data set according to the distribution of numbers of pulses recorded for a series of fixed-length intervals, which for random pulses follows the Poisson distribution. Again, as the length of the interval increases, the distribution conforms to the central limit theorem: it becomes normal with a well-defined mean and width, both related to mean and width of the underlying distribution. The software also allows students to simulate pulse-intervals that follow a uniform distribution (e.g., any real number between 0 and 1 has equal probability) or a Gaussian one. In these cases, one can see that the counts per fixed interval length do not follow the Poisson distribution, although all types become normal at longer intervals or greater numbers of pulses per interval length. This serves to drive home the point that cosmic ray counts are truly a Poisson process and also to illustrate the significant power of the central limit theorem that regardless of the underlying probability distribution function, when N becomes large the distribution becomes normal with a well-defined mean and width. Presented at the 2013 AAPT Summer Meeting in Portland, Oregon. W36: Advanced Labs Workshop

Pengra, David B.

2013-10-02

387

ATIC Measurement of Cosmic Ray Heavy Ions  

NASA Astrophysics Data System (ADS)

The Advanced Thin Ionization Calorimeter (ATIC), a Long Duration Balloon (LDB) experiment, is designed to measure the charge composition (for Z from 1 to 28) and energy spectra of primary cosmic rays in the region of total energy from 100 GeV to near 100 TeV. The instrument is built around a fully active, Bismuth Germanate (BGO) ionization calorimeter to measure the energy deposited by the cascades formed by particles interacting in a thick carbon target. A highly segmented silicon matrix, located above the target, provides good incident charge resolution plus rejection of the "backscattered" particles from the interaction. Trajectory reconstruction is based on the cascade profile in the BGO calorimeter, plus information from the three scintillator hodoscope layers in the target section above it. The hodoscope planes also provide the primary event trigger to initiate the detector readout, another measure of the incident particle charge and an indicator of the interaction point in the carbon material. The scientific payload weighs 1,540 kg and consumes 300 Watts of power supplied by a 580 Watt solar array system. The instrument was launched from McMurdo, Antarctica on 29 December 2002 and was carried to an altitude of 37 km above Antarctica by a 850,000 m3 helium filled balloon for one circumnavigation of the continent yielding about 19 days of data. The subsequent data analysis resulted in element identification up to the Iron peak. Monte Carlo simulations were used to convert energy deposition measurements to primary energy. Here we discuss and interpret the preliminary energy spectra for the abundant cosmic ray elements and compare them with results from other experiments.

Guzik, T. G.; ATIC Collaboration

2004-08-01

388

Cosmic ray anisotropy as signature for the transition from galactic to extragalactic cosmic rays  

NASA Astrophysics Data System (ADS)

We constrain the energy at which the transition from Galactic to extragalactic cosmic rays occurs by computing the anisotropy at Earth of cosmic rays emitted by Galactic sources. Since the diffusion approximation starts to loose its validity for E/Zgtrsim1016-17 eV, we propagate individual cosmic rays using Galactic magnetic field models and taking into account both their regular and turbulent components. The turbulent field is generated on a nested grid which allows spatial resolution down to fractions of a parsec. Assuming sufficiently frequent Galactic CR sources, the dipole amplitude computed for a mostly light or intermediate primary composition exceeds the dipole bounds measured by the Auger collaboration around E ? 1018 eV. Therefore, a transition at the ankle or above would require a heavy composition or a rather extreme Galactic magnetic field with strength gtrsim10 ?G. Moreover, the fast rising proton contribution suggested by KASCADE-Grande data between 1017 eV and 1018 eV should be of extragalactic origin. In case heavy nuclei dominate the flux at Egtrsim1018 eV, the transition energy can be close to the ankle, if Galactic CRs are produced by sufficiently frequent transients as e.g. magnetars.

Giacinti, G.; Kachelrie, M.; Semikoz, D. V.; Sigl, G.

2012-07-01

389

Galactic Cosmic Ray Composition Beyond the Fe-Group and the Origin of Cosmic Rays  

NASA Astrophysics Data System (ADS)

We review the present status of cosmic ray composition measurements in the middle third of the periodic table using data from three sources. The Advanced Composition Explorer (ACE) has now completed more than 16 years in orbit and its Cosmic Ray Isotope Spectrometer (CRIS) has now collected more than 200 nuclei with Z = 31-40, somewhat more than were recorded in two earlier balloon flights by the Trans-Iron Galactic Element Recorder (TIGER). Both of these data sets provide individual element resolution and they agree well. Combining the two data sets we find a mass-dependent ordering of both refractory and volatile elements when compared with massive star outflow and supernova ejecta mixed with normal interstellar material. Refractory elements are preferentially accelerated by a factor of ~4. These data support an OB-association origin of galactic cosmic rays. Finally, we take a first look at new composition data from Super-TIGER, which has achieved both improved charge resolution and collecting power with a single record-breaking 55-day balloon flight.

Mewaldt, Richard

390

Cosmic ray anisotropy as signature for the transition from galactic to extragalactic cosmic rays  

SciTech Connect

We constrain the energy at which the transition from Galactic to extragalactic cosmic rays occurs by computing the anisotropy at Earth of cosmic rays emitted by Galactic sources. Since the diffusion approximation starts to loose its validity for E/Z?>10{sup 16?17} eV, we propagate individual cosmic rays using Galactic magnetic field models and taking into account both their regular and turbulent components. The turbulent field is generated on a nested grid which allows spatial resolution down to fractions of a parsec. Assuming sufficiently frequent Galactic CR sources, the dipole amplitude computed for a mostly light or intermediate primary composition exceeds the dipole bounds measured by the Auger collaboration around E ? 10{sup 18} eV. Therefore, a transition at the ankle or above would require a heavy composition or a rather extreme Galactic magnetic field with strength ?>10 ?G. Moreover, the fast rising proton contribution suggested by KASCADE-Grande data between 10{sup 17} eV and 10{sup 18} eV should be of extragalactic origin. In case heavy nuclei dominate the flux at E?>10{sup 18} eV, the transition energy can be close to the ankle, if Galactic CRs are produced by sufficiently frequent transients as e.g. magnetars.

Giacinti, G.; Kachelrie, M. [Institutt for fysikk, NTNU, Trondheim (Norway); Semikoz, D.V. [AstroParticle and Cosmology (APC), Paris (France); Sigl, G. [II. Institut fr Theoretische Physik, Universitt Hamburg, Hamburg (Germany)

2012-07-01

391

PREFACE: Cosmic Ray Anisotropy Workshop 2013 (CRA2013)  

NASA Astrophysics Data System (ADS)

In the search for the origin of cosmic rays in our galaxy, various observations are combined as pieces of a complex puzzle to account for the variability of the galactic sources and their local environments, as well as of the properties of the interstellar medium in which cosmic particles propagate. In this puzzle, multi-wavelength observations aim to pinpoint the properties of cosmic-ray sources, based on electromagnetic and neutrino emissions associated with hadronic acceleration processes. The detailed study of the energy spectrum and composition of cosmic rays on Earth, on the other hand, aims to probe the combined and interwoven effects of injection, by acceleration processes, and propagation in the interstellar medium. The observation of arrival directions of cosmic rays on Earth, in addition, potentially provides valuable information on the distribution of the closest and more recent active galactic sources as well as on the properties of the local interstellar magnetic field. The quasi-isotropic distribution of galactic cosmic rays tells the global story of their journey from their sources. The turbulent magnetized galactic medium sufficiently scrambles the arrival directions of cosmic rays on Earth so that their main injection direction is concealed. On the other hand, the observations of a small but significant energy-dependent anisotropy are starting to provide clues on how cosmic rays propagate throughout the local interstellar medium. Anisotropy observations have been used to study diffusion properties of GeV cosmic rays inside the termination shock of the heliosphere and their dependencies on solar cycles. At TeV energy, cosmic rays are sensitive to larger-scale magnetic structures, such as the turbulent boundary between the heliosphere and the local interstellar medium or its elongated tail. At higher energy, it is expected that the interstellar magnetic field within the particle mean free path has major contributions to their arrival directions on Earth. In this workshop, we addressed the potential use of high-energy cosmic-ray anisotropy observations as a probe into the properties of particle transport in astrophysical magnetized plasmas, such as the heliosphere and the local interstellar medium. Along with experts from the fields of astronomy, astrophysics, plasma physics, heliospheric physics and interstellar medium, we discussed how each field can contribute to the understanding of cosmic-ray propagation in our local interstellar magnetic field. This will represent another piece in the search for cosmic-ray sources in the galaxy.

2014-08-01

392

Cosmic Ray Signatures from Decaying Gravitino Dark Matter  

E-print Network

We study the charged cosmic rays arising from the slow decay of gravitino dark matter within supersymmetric scenarios with trilinear R-parity violation. It is shown that operators of the LLE type can very well account for the recent anomalies in cosmic ray electron and positron data reported by PAMELA, ATIC and Fermi LAT, without violating any other bounds. This scenario will soon be tested by the Fermi LAT data on diffuse gamma ray emission.

N. -E. Bomark; S. Lola; P. Osland; A. R. Raklev

2009-11-18

393

Cosmic Ray production of Beryllium and Boron at high redshift  

E-print Network

Recently, new observations of Li6 in Pop II stars of the galactic halo have shown a surprisingly high abundance of this isotope, about a thousand times higher than its predicted primordial value. In previous papers, a cosmological model for the cosmic ray-induced production of this isotope in the IGM has been developed to explain the observed abundance at low metallicity. In this paper, given this constraint on the Li6, we calculate the non-thermal evolution with redshift of D, Be, and B in the IGM. In addition to cosmological cosmic ray interactions in the IGM, we include additional processes driven by SN explosions: neutrino spallation and a low energy component in the structures ejected by outflows to the IGM. We take into account CNO CRs impinging on the intergalactic gas. Although subdominant in the galactic disk, this process is shown to produce the bulk of Be and B in the IGM, due to the differential metal enrichment between structures (where CRs originate) and the IGM. We also consider the resulting extragalactic gamma-ray background which we find to be well below existing data. The computation is performed in the framework of hierarchical structure formation considering several star formation histories including Pop III stars. We find that D production is negligible and that a potentially detectable Be and B plateau is produced by these processes at the time of the formation of the Galaxy (z ~ 3).

Emmanuel Rollinde; David Maurin; Elisabeth Vangioni; Keith A. Olive; Susumu Inoue

2007-07-13

394

Searching for New Physics with Ultrahigh Energy Cosmic Rays  

NASA Technical Reports Server (NTRS)

Ultrahigh energy cosmic rays that produce giant extensive showers of charged particles and photons when they interact in the Earth's atmosphere provide a unique tool to search for new physics. Of particular interest is the possibility of detecting a very small violation of Lorentz invariance such as may be related to the structure of space-time near the Planck scale of approximately 10 (exp -35) m. We discuss here the possible signature of Lorentz invariance violation on the spectrum of ultrahigh energy cosmic rays as compared with present observations of giant air showers. We also discuss the possibilities of using more sensitive detection techniques to improve searches for Lorentz invariance violation in the future. Using the latest data from the Pierre Auger Observatory, we derive a best fit to the LIV parameter of 3 .0 + 1.5 - 3:0 x 10 (exp -23) ,corresponding to an upper limit of 4.5 x 10-23 at a proton Lorentz factor of approximately 2 x 10(exp 11) . This result has fundamental implications for quantum gravity models.

Stecker, Floyd W.; Scully, Sean T.

2009-01-01

395

Low-Energy Cosmic-Ray Events Associated with Solar Flares  

Microsoft Academic Search

As a result of the IGY riometer program, it has been found that the measure- ment of ionospheric absorption in arctic regions is a sensitive method of detecting low-energy cosmic rays associated with solar flares. The normal morphology of these events is described, and details are given of the 24 such events that have been detected in the period from

George C. Reid; Harold Leinbach

1959-01-01

396

Change in cosmic-ray spectrum through the production of electron-positron pairs (analytical approach)  

SciTech Connect

We consider the change in primordial cosmic-ray spectrum through the production of electron-positron pairs in collisions with cosmic microwave background radiation photons. We suggest using these results to estimate the distances to cosmic-ray sources.

Vlasov, V. P., E-mail: vlasov@nfi.kiae.ru; Trubnikov, B. A., E-mail: batrub@nfi.kiae.r [Russian Research Center Kurchatov Institute (Russian Federation)

2009-12-15

397

Relationship between the Neutron Time Delay Distribution and the Rigidity Spectrum of Primary Cosmic Rays  

NASA Astrophysics Data System (ADS)

Neutron monitors are the premier instruments for precisely tracking time variations in the galactic cosmic ray flux at GeV-range energies above the geomagnetic cutoff at the location of measurement. Recently, a new capability has been developed to record and analyze the neutron time delay distribution (related to neutron multiplicity) to infer variations in the cosmic ray spectrum as well. In particular, we can determine the leader fraction L, defined as the fraction of neutrons that did not follow a previous neutron detection in the same tube from the same nuclear interaction, from time delay histograms. By analyzing data taken during 1995-2007 by a ship-borne neutron monitor latitude survey we confirm a strong dependence of L on the geomagnetic cutoff. We have also developed Monte Carlo simulations of cosmic ray interactions in the atmosphere and in a neutron monitor, and trace cosmic ray trajectories through Earth's magnetic field to model how the cosmic ray spectrum is suppressed at low rigidity at a given geographic location. The simulation results show a variation of L with geomagnetic cutoff as observed by the latitude survey, confirming that these changes in L can reasonably be attributed to changes in the cosmic ray spectrum.

Mangeard, Pierre-Simon; Bieber, John W.; Duldig, Marcus L.; Humble, John E.; Pyle, Roger; Evenson, Paul; Ruffolo, David; Saiz, Alejandro; Nuntiyakul, Waraporn

398

Galactic Propagation of Cosmic Rays from Individual Supernova Remnants  

E-print Network

It is widely believed that supernova remnants are the best candidate sources for the observed cosmic ray flux up to the knee, i.e. up to ~PeV energies. Indeed, the gamma-ray spectra of some supernova remnants can be well explained by assuming the decay of neutral pions which are created in hadronic interactions. Therefore, fitting the corresponding gamma spectra allows us to derive the spectra of cosmic rays at the source which are locally injected into our Galaxy. Using these spectra as a starting point, we propagate the cosmic rays through the Galaxy using the publicly available GALPROP code. Here, we will present first results on the contribution of those SNRs to the total cosmic ray flux and discuss implications.

Nierstenhoefer, Nils; Schuppan, Florian; Tjus, Julia Becker

2015-01-01

399

Predicting the Cosmic-Ray Environment Near Earth  

NASA Technical Reports Server (NTRS)

Package of computer programs developed to predict cosmic-ray environment for spacecraft in orbit near Earth. Single cosmic-ray particle deposits enough electrical charge on sensitive area of individual circuit to change bit state. Single-event upsets may not cause permanent damage but upset functioning devices. Used to predict upset rate for space mission. Also calculates time-average cosmic-ray environment for multiple circular orbits, fragments of trajectories, and isolated points. Package written in HPL for interactive execution and implemented on HP 9825B desktop computer.

Edmonds, L.

1986-01-01

400

Cosmic-ray antimatter - A primary origin hypothesis  

NASA Technical Reports Server (NTRS)

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

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

1983-01-01

401

Cosmic-ray acceleration at stellar wind terminal shocks  

NASA Technical Reports Server (NTRS)

Steady-state spherically symmetric analytic solutions of the cosmic-ray transport equations, applicable to the problem of acceleration of cosmic rays at the terminal shock to a stellar wind, are studied. The spectra, graidents, and flow patterns of particles modulated and accelerated by the stellar wind and shock are investigated by means of monoenergetic-source solutions at finite radius, as well as solutions with monoenergetic and power-law galactic spectra. On the basis of calculations given, early-type stars could supply a significant fraction of the 3 x 10 to the 40th ergs/sec required by galactic cosmic rays.

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

1985-01-01

402

Calculations of cosmic-ray helium transport in shielding materials  

NASA Technical Reports Server (NTRS)

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.

Cucinotta, Francis A.

1993-01-01

403

Solar Variability, Cosmic Rays and Climate: What's up? The topic of possible relations between solar and cosmic  

E-print Network

Preface Solar Variability, Cosmic Rays and Climate: What's up? The topic of possible relations between solar and cosmic ray variability on one hand, and Earth's climate on the other hand, is quite in Space Research topical issue on Solar Variability, Cosmic Rays and Climate presents a collection

Usoskin, Ilya G.

404

A connection between star formation activity and cosmic rays in the starburst galaxy M82  

NASA Astrophysics Data System (ADS)

Although Galactic cosmic rays (protons and nuclei) are widely believed to be mainly accelerated by the winds and supernovae of massive stars, definitive evidence of this origin remains elusive nearly a century after their discovery. The active regions of starburst galaxies have exceptionally high rates of star formation, and their large size-more than 50 times the diameter of similar Galactic regions-uniquely enables reliable calorimetric measurements of their potentially high cosmic-ray density. The cosmic rays produced in the formation, life and death of massive stars in these regions are expected to produce diffuse ?-ray emission through interactions with interstellar gas and radiation. M82, the prototype small starburst galaxy, is predicted to be the brightest starburst galaxy in terms of ?-ray emission. Here we report the detection of >700-GeV ?-rays from M82. From these data we determine a cosmic-ray density of 250eVcm-3 in the starburst core, which is about 500 times the average Galactic density. This links cosmic-ray acceleration to star formation activity, and suggests that supernovae and massive-star winds are the dominant accelerators.

VERITAS Collaboration; Acciari, V. A.; Aliu, E.; Arlen, T.; Aune, T.; Bautista, M.; Beilicke, M.; Benbow, W.; Boltuch, D.; Bradbury, S. M.; Buckley, J. H.; Bugaev, V.; Byrum, K.; Cannon, A.; Celik, O.; Cesarini, A.; Chow, Y. C.; Ciupik, L.; Cogan, P.; Colin, P.; Cui, W.; Dickherber, R.; Duke, C.; Fegan, S. J.; Finley, J. P.; Finnegan, G.; Fortin, P.; Fortson, L.; Furniss, A.; Galante, N.; Gall, D.; Gibbs, K.; Gillanders, G. H.; Godambe, S.; Grube, J.; Guenette, R.; Gyuk, G.; Hanna, D.; Holder, J.; Horan, D.; Hui, C. M.; Humensky, T. B.; Imran, A.; Kaaret, P.; Karlsson, N.; Kertzman, M.; Kieda, D.; Kildea, J.; Konopelko, A.; Krawczynski, H.; Krennrich, F.; Lang, M. J.; Lebohec, S.; Maier, G.; McArthur, S.; McCann, A.; McCutcheon, M.; Millis, J.; Moriarty, P.; Mukherjee, R.; Nagai, T.; Ong, R. A.; Otte, A. N.; Pandel, D.; Perkins, J. S.; Pizlo, F.; Pohl, M.; Quinn, J.; Ragan, K.; Reyes, L. C.; Reynolds, P. T.; Roache, E.; Rose, H. J.; Schroedter, M.; Sembroski, G. H.; Smith, A. W.; Steele, D.; Swordy, S. P.; Theiling, M.; Thibadeau, S.; Varlotta, A.; Vassiliev, V. V.; Vincent, S.; Wagner, R. G.; Wakely, S. P.; Ward, J. E.; Weekes, T. C.; Weinstein, A.; Weisgarber, T.; Williams, D. A.; Wissel, S.; Wood, M.; Zitzer, B.

2009-12-01

405

Detectability of the first cosmic explosions  

NASA Astrophysics Data System (ADS)

We present a fully self-consistent simulation of a synthetic survey of the furthermost cosmic explosions. The appearance of the first generation of stars (Population III) in the Universe represents a critical point during cosmic evolution, signalling the end of the dark ages, a period of absence of light sources. Despite their importance, there is no confirmed detection of Population III stars so far. A fraction of these primordial stars are expected to die as pair-instability supernovae (PISNe), and should be bright enough to be observed up to a few hundred million years after the big bang. While the quest for Population III stars continues, detailed theoretical models and computer simulations serve as a testbed for their observability. With the upcoming near-infrared missions, estimates of the feasibility of detecting PISNe are not only timely but imperative. To address this problem, we combine state-of-the-art cosmological and radiative simulations into a complete and self-consistent framework, which includes detailed features of the observational process. We show that a dedicated observational strategy using ? 8 per cent of the total allocation time of the James Webb Space Telescope mission can provide us with up to 9-15 detectable PISNe per year.

de Souza, R. S.; Ishida, E. E. O.; Johnson, J. L.; Whalen, D. J.; Mesinger, A.

2013-12-01

406

Prospects for Detecting a Cosmic Bulk Flow  

NASA Astrophysics Data System (ADS)

The ?CDM model is based upon a homogeneous, isotropic space-time leading to uniform expansion with random peculiar velocities caused by local gravitation perturbations. The Cosmic Microwave Background (CMB) radiation evidences a significant dipole moment in the frame of the Local Group. This motion is usually explained with the Local Group's motion relative to the background Hubble expansion. An alternative explanation, however, is that the dipole moment is the result of horizon-scale curvature remaining from the birth of space-time, possibly a result of quantum entanglement with another universe. This would appear as a single velocity (a bulk flow) added to all points in space. These two explanations differ observationally on cosmic distance scales (z > 0.1). There have been many differing attempts to detect a bulk flow, many with no detectable bulk flow but some with a bulk flow velocity as large as 1000 km/s. Here we report on a technique based upon minimizing the scatter around the expected cosine distribution of the Hubble redshift residuals with respect to angular distance on the sky. That is, the algorithm searches for a directional dependence of Hubble residuals. We find results consistent with most other bulk flow detections at z < 0.05, i.e. a bulk flow velocity of ~300 km/s pointed at (l, b) = (280, 29) in galactic coordinates. Simulations were run to analyze whether a bulk flow can be detected at higher redshifts, z < 0.3. For detecting a bulk flow velocity of <1,000 km/s at such distances one would need distance modulus errors from Type Ia Supernovae to be ~0.01, whereas the current error (~0.2.) is more than an order of magnitude too large for the detection of bulk flow beyond z~0.05.

Rose, Benjamin; Garnavich, Peter M.; Mathews, Grant James

2015-01-01

407

Computations of cosmic ray propagation in the Earth's atmosphere, towards a GLE analysis  

E-print Network

Computations of cosmic ray propagation in the Earth's atmosphere, towards a GLE analysis A Mishev 1 measurements. In this study a simulation of cosmic ray atmospheric cascade is carried out with PLANETOCOSMICS. Introduction The Earth is constantly hit by high energy particles - cosmic ray. The primary cosmic ray (CR

Usoskin, Ilya G.

408

The Cosmic-ray Spectrum: from the knee to the T K Gaisser  

E-print Network

The Cosmic-ray Spectrum: from the knee to the ankle T K Gaisser Bartol Research Institute the question, "Where is the transition from cosmic rays of galactic origin to extra-galactic cosmic-rays?" I It is a commonplace, nearly a century after the discovery of cosmic rays, that their origin remains a mystery

409

Exploring Cosmic X-ray Source Polarization  

NASA Technical Reports Server (NTRS)

Cosmic X-ray sources are expected to be polarized, either because of their asymmetry and the role of scattering in their emission or the role of magnetic fields. Polarization at other wavelengths has been useful. X-ray polarization will provide a new handle on black hole parameters, in particular the spin, on accretion flows and outflows, on neutron star spin orientations and emission mechanisms, on the quantum mechanical effects of super-strong magnetic fields of magnetars, and on the structure of supernovae shocks. The proposed Gravity and Extreme Magnetism SMEX (GEMS) will use high efficiency polarimeters behind thin foil mirrors. The statistical sensitivity and control of systematics will allow measurement of polarization fractions as small as 1% from many galactic and extragalactic sources. Targets which should be polarized at the level that GEMS can easily measure include stellar black holes, Seyfert galaxies and quasars, blazars, rotation-powered and accretion-powered pulsars, magnetars, shell supernova remnants and pulsar wind nebulae. The polarimeters are Time Projection Chambers that allow reconstruction of images of photoelectron tracks for 2-10 keV Xrays. They can be deep without sacrificing modulation. These polarimeters do not image the sky, but the telescope point spread function and detector collimation allow structure to be resolved at the 10 arcmin level. Rotation of the spacecraft is not needed for the signal measurement in the Time Projection Chambers, but provides for measurement and correction of systematic errors. It also allows a small Bragg reflection soft X-ray experiment to be included that can be used for isolated neutron stars and blazars.

Swank, Jean Hebb; Jahodal, K.; Kallman, T. R.; Kaaret, P.

2008-01-01

410

The History of Cosmic Ray Studies after Hess  

NASA Astrophysics Data System (ADS)

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

Grupen, Claus

2013-06-01

411

Cosmic String Detection via Microlensing of Stars  

E-print Network

Cosmic superstrings are produced towards the end of the brane inflation. If the string tension is low enough, loops tend to be relatively long-lived. The resultant string network is expected to contain many loops which are smaller than typical Galactic scales. Cosmic expansion damps the center of mass motion of the loops which then cluster like cold dark matter. Loops will lens stars within the galaxy and local group. We explore microlensing of stars as a tool to detect and to characterize some of the fundamental string and string network properties, including the dimensionless string tension $G \\mu/c^2$ and the density of string loops within the Galaxy. As $G \\mu \\to 0$ the intrinsic microlensing rate diverges as $1/\\sqrt{G \\mu}$ but experimental detection will be limited by shortness of the lensing timescale and/or smallness of the bending angle which each vary $\\propto G \\mu$. We find that detection is feasible for a range of tensions. As an illustration, the planned optical astrometric survey mission, Gaia, should be able to detect numerous microlensing events for string networks with tensions $10^{-10} \\simless G \\mu \\simless 10^{-6}$. A null result for optical microlensing implies $G \\mu \\simless 10^{-10}$. If lensing of a given source is observed it will repeat because the internal motions of the loop are relativistic but the center of mass motion may be much smaller, of order the halo velocity. This distinctive hallmark $\\sim 1000$ repetitions, suggests a useful method for confirmation of a potential lensing detection.

David F. Chernoff; S. -H. Henry Tye

2007-09-09

412

EMMAa new underground cosmic-ray experiment  

NASA Astrophysics Data System (ADS)

An experiment observing underground muons originating from cosmic-ray air showers is under preparation in the Pyhsalmi mine, Finland. The aim is to cover an area of about 200 300 m2, and the detector setup is capable of measuring the muon multiplicity and their lateral distribution. The detector is placed at a depth of about 85 m (corresponding about 240 m w.e.), which gives a threshold energy of muons of about 45 GeV. The detection of the multimuon events is motivated by partly unknown composition of the primary cosmic rays in the energy region of 1015 1016 eV, i.e., the knee region. In addition, by measuring only the higher energy muons of the air shower, the lowest energy muons being filtered out by the rock overburden, the data is sensitive also to the studies of the upper parts of the air shower. The experiment will be constructed mainly using drift chambers used previously in LEP detectors at CERN, but it can also be expanded using plastic scintillator detectors. The prototype detector is expected to be running in the beginning of 2006, and the full-size detector by the end of 2007.

Enqvist, T.; Fhr, V.; Joutsenvaara, J.; Kernen, P.; Kuusiniemi, P.; Laitala, H.; Lehtola, M.; Mattila, A.; Narkilahti, J.; Nurmenniemi, S.; Peltoniemi, J.; Remes, H.; Rih, T.; Shen, C.; Reponen, M.; Sarkamo, J.; Vaittinen, M.; Zhang, Z.; Jmsn, T.; Ding, L.; Zhu, Q.; Roos, M.; Dzaparova, I.; Karpov, S.; Kurenya, A.; Petkov, V.; Yanin, A.; Fynbo, H.

2007-01-01

413

Scintillation Light from Cosmic-Ray Muons in Liquid Argon  

E-print Network

This paper reports the results of the first experiment to directly measure the properties of the scintillation light generated by minimum ionizing cosmic-ray muons in liquid argon. Scintillation light from these muons is of value to studies of weakly-interacting particles in neutrino experiments and dark matter searches, as well as for particle identification. The experiment was carried out at the TallBo facility at Fermilab using prototype light guides and electronics developed for the Long-Baseline Neutrino Experiment. Analysis of the time-resolved structure of the scintillation light from cosmic-ray muons gives $\\langle \\tau_{\\text{T}}\\rangle = 1.43 \\pm 0.04~\\text{(stat.)} \\pm 0.007~\\text{(sys.)}~\\mu$s for the triplet light decay time constant. The ratio of singlet to triplet light measured using surface-coated light guides is $R = 0.39 \\pm 0.01~\\text{(stat.)} \\pm 0.008~\\text{(sys.)}$. There is some evidence that this value is not consistent with $R$ for minimum ionizing electrons. However, the value for $R$ measured here clearly differs significantly from $R$ found for heavily ionizing particles like alphas. Furthermore, there is no apparent difference in $R$ measured using light guides coated with TPB versus bis-MSB, adding additional evidence that bis-MSB is a promising alternative to TPB for detecting scintillation light in liquid argon.

Denver Whittington; Stuart Mufson

2014-08-08

414

A local recent supernova - Evidence from X-rays, Al-26 radioactivity and cosmic rays  

NASA Technical Reports Server (NTRS)

Possible ways in which cosmic rays could have been contaminated by a local recent supernova are discussed, and ways in which this contamination may be affecting interpretation of Al-26 gamma radiation and locally observed cosmic rays as samples of the average Galactic distribution are considered. Mass spectra of cosmic rays are examined to see whether there is enrichment by a population arising from supernova preacceleration. The reinterpretation of the anomalous component in terms of a local supernova model is addressed.

Clayton, Donald D.; Cox, Donald P.; Michel, Curtis F.

1986-01-01

415

Nonlinear Transport of Cosmic Rays in Turbulent Magnetic Field  

NASA Astrophysics Data System (ADS)

Recent advances in both the MHD turbulence theory and cosmic ray observations call for revisions in the paradigm of cosmic ray transport. We use the models of magnetohydrodynamic turbulence that were tested in numerical simulations, in which turbulence is injected at large scale and cascades to small scales. We shall present the nonlinear results for cosmic ray transport, in particular, the cross field transport of CRs. We demonstrate that the concept of cosmic ray subdiffusion in general does not apply and the perpendicular motion is well described by normal diffusion with M A4 dependence. Moreover, on scales less than the injection scale of turbulence, CRs' transport becomes super-diffusive. Quantitative predictions for both the normal diffusion on large scale and super diffusion on small scale are confirmed with recent numerical simulations. Implication for shock acceleration is briefly discussed.

Yan, H.; Xu, S.

2014-09-01

416

Supernova envelope shock origin of cosmic rays: a review  

SciTech Connect

The hydrodynamic shock origin of cosmic rays in the envelope of a Type I presupernova star is reviewed. The possibility of accelerating ultrahigh energy particles to greater than or equal to 10/sup 18/ eV is unique to the shock mechanism and currently no other suggested galactic or extragalactic site is likely. In this paper a review of the work leading to a renewed commitment to the origin of cosmic rays in the shock ejected envelope of supernova is given. The degree to which this interpretation applies to the origin of all cosmic rays is certainly uncertain and does not exclude the possibility of a fraction of the lower energy cosmic rays being accelerated in collisionless plasma shocks in the interstellar medium. 45 references, 3 figures.

Colgate, S.A.

1984-01-01

417

Cosmic Rays and Their Radiative Processes in Numerical Cosmology  

E-print Network

A cosmological hydrodynamic code is described, which includes a routine tocompute cosmic ray acceleration and transport in a simplified way. The routinewas designed to follow explicitly diffusive acceleration at shocks, andsecond-order Fermi acceleration and adiabatic loss in smooth flows. Synchrotroncooling of the electron population can also be followed. The updated code isintended to be used to study the properties of nonthermal synchrotron emissionand inverse Compton scattering from electron cosmic rays in clusters ofgalaxies, in addition to the properties of thermal bremsstrahlung emission fromhot gas. The results of a test simulation using a grid of $128^3$ cells arepresented, where cosmic rays and magnetic field have been treated passively andsynchrotron cooling of cosmic ray electrons has not been included.

Ryu, D; Jones, T W; Kang, H; Ryu, Dongsu; Miniati, Francesco; Jones, Tom W.; Kang, Hyesung

1999-01-01

418

Highest-Energy Cosmic Rays and Hilbertian Repulsive Effect  

E-print Network

We point out that an important portion of the high energy of the cosmic rays from extragalactic sources can be attributed to a Hilbertian repulsive effect, which is a consequence of Einstein equations without cosmological term.

Angelo Loinger; Tiziana Marsico

2007-12-22

419

Hydrodynamical constraints on cosmic-ray acceleration in relativistic shocks  

NASA Technical Reports Server (NTRS)

A two-fluid hydrodynamical model governing the transport of cosmic rays in a relativistically moving background plasma is developed. The equations are used to discuss the time asymptotic structure of a relativistic, plane-parallel shock wave significantly modified by first-order Fermi acceleration of cosmic rays. The model allows for an anisotropic cosmic-ray pressure tensor with pressure components parallel and perpendicular to the shock normal. It is surmised that the well-known energy threshold problem for diffusive shock acceleration that downstream particles have a large enough velocity to overtake the shock and subsequently scatter in the upstream medium before returning to the downstream medium may be expressed hydrodynamically by the condition V less than V(cr), where V is the fluid velocity relative to the shock and V(cr) is the relativistic cosmic-ray sound speed. Astrophysical implications of the results are briefly discussed.

Webb, G. M.

1987-01-01

420

Heavy quark production in ultra high energy cosmic ray interactions  

NASA Astrophysics Data System (ADS)

In this paper we present a comprehensive study of the heavy quark production in ultra high energy cosmic ray interactions in the atmosphere considering that the primary cosmic ray can be either a photon, neutrino or a proton. The analysis is performed using a unified framework - the dipole formalism - and the saturation effects, associated to the physical process of parton recombination, are taken into account. We demonstrate that the contribution of heavy quarks for cosmic ray interactions is in general non-negligible and can be dominant depending of the process considered. Moreover, our results indicate that new dynamical mechanisms should be included in order to obtain reliable predictions for the heavy quark production in pp collisions at ultra high cosmic ray energies.

Gonalves, V. P.; Gratieri, D. R.

2015-02-01

421

Thunderstorms, cosmic rays, and solar-lunar influences  

SciTech Connect

A study of cosmic rays and thunderstorm frequency has shown a decrease in thunderstorms at the time of high cosmic rays and an increase in thunderstorms 2-4 days later. This was done by superposed epoch analysis of thunderstorms over the eastern two thirds of the United States for 1957-1976. When data for spring and fall months were used, the minimum deepened. When high cosmic rays near full and new moon for these months were key days, the minimum deepened again and was significant at less than the 0.01% level. It is believed that when the Sun, Earth, and Moon are aligned, particulate matter in the lower stratosphere is modulated and acted upon by cosmic rays, bringing about an immediate decrease in thunderstorms.

Lethbridge, M.D.

1990-08-20

422

The cosmic ray muon energy spectum via ?erenkov radiation  

E-print Network

In this thesis, I designed and constructed a basic Cerenkov detector to measure the energy spectrum of cosmic ray muons for use in the graduate experimental physics courses, 8.811/2. The apparatus consists of a light-tight ...

Quintero, Eric Antonio

2010-01-01

423

The Determination of the Muon Magnetic Moment from Cosmic Rays  

ERIC Educational Resources Information Center

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)

Amsler, C.

1974-01-01

424

Heliosphere Changes Affect Cosmic Ray Penetration - Duration: 0:18.  

NASA Video Gallery

The changes in the size of our solar system??s boundaries also cause changes to the galactic cosmic rays that enter the solar system. Although these boundaries do a good job of deflecting the majo...

425

Separation of the geomagnetic variation of cosmic rays  

NASA Astrophysics Data System (ADS)

The contributions of geomagnetic variations and complex variations in cosmic ray intensities to measured variations in the neutron component of cosmic ray flux are separated by a study of normalized neutron intensities recorded at three stations with different cut-off rigidities. The correlation between Dst variations and temporal variations in normalized intensity differences is calculated for stations with rigidities of 0.0, 4.0 and 13 GV during the large magnetic storm (300 nT) of March 5-13, 1970. Results show the increase in cosmic ray intensities observed during the storm to be due to a decrease in cosmic ray cut-off rigidities. The maximum Dst decrease of 280 nT is found to lead to a 3.2 percent variation in the intensity difference between Dallas and Churchill stations, and a 4.2 percent variation in the difference between Chacataya and Churchill, in agreement with theoretical calculations.

Zhumabaev, B. T.; Kozin, I. D.

426

Cosmic ray scintillations. II - General theory of interplanetary scintillations  

NASA Technical Reports Server (NTRS)

The motion of charged particles in a stochastic magnetic field with nonzero mean is considered via a generalized quasi-linear expansion of Liouville's equation. The general result is an equation relating cosmic ray scintillations to magnetic fluctuations and to cosmic ray gradients. The resonant interaction between particles and the random magnetic field is considered in detail, and the effect of nonlinear terms in the equations is considered. The nonlinear terms are important in damping out initial conditions and in determining conditions near cyclotron resonances. The application of the theory to the propagation of cosmic rays during quiet times in interplanetary space is considered. It is concluded that cosmic ray scintillations in interplanetary space may provide useful information about interplanetary particles and fields and also about nonlinear plasma interactions.

Owens, A. J.

1974-01-01

427

UNDERSTANDING TeV-BAND COSMIC-RAY ANISOTROPY  

SciTech Connect

We investigate the temporal and spectral correlations between flux and anisotropy fluctuations of TeV-band cosmic rays in light of recent data taken with IceCube. We find that for a conventional distribution of cosmic-ray sources, the dipole anisotropy is higher than observed, even if source discreteness is taken into account. Moreover, even for a shallow distribution of galactic cosmic-ray sources and a reacceleration model, fluctuations arising from source discreteness provide a probability only of the order of 10% that the cosmic-ray anisotropy limits of the recent IceCube analysis are met. This probability estimate is nearly independent of the exact choice of source rate, but generous for a large halo size. The location of the intensity maximum far from the Galactic Center is naturally reproduced.

Pohl, Martin [DESY, D-15738 Zeuthen (Germany)] [DESY, D-15738 Zeuthen (Germany); Eichler, David, E-mail: pohlmadq@gmail.com, E-mail: eichler@bgu.ac.il [Physics Department, Ben-Gurion University, Be'er-Sheva 84105 (Israel)] [Physics Department, Ben-Gurion University, Be'er-Sheva 84105 (Israel)

2013-03-20

428

A high-resolution study of ultra-heavy cosmic-ray nuclei (A0178)  

NASA Technical Reports Server (NTRS)

The main objective of the experiment is a detailed study of the charge spectra of ultraheavy cosmic-ray nuclei from zinc (Z = 30) to uranium (Z = 92) and beyond using solid-state track detectors. Special emphasis will be placed on the relative abundances in the region Z or - 65, which is thought to be dominated by r-process nucleosynthesis. Subsidiary objectives include the study of the cosmic-ray transiron spectrum a search for the postulated long-lived superheavy (SH) nuclei (Z or = 110), such as (110) SH294, in the contemporary cosmic radiation. The motivation behind the search for super-heavy nuclei is based on predicted half-lives that are short compared to the age of the Earth but long compared to the age of cosmic rays. The detection of such nuclei would have far-reaching consequences for nuclear structure theory. The sample of ultraheavy nuclei obtained in this experiment will provide unique opportunities for many tests concerning element nucleosynthesis, cosmic-ray acceleration, and cosmic-ray propagation.

Osullivan, D.; Thompson, A.; Oceallaigh, C.; Domingo, V.; Wenzel, K. P.

1984-01-01

429

Gamma-Ray, Cosmic Ray and Neutrino Tests of Lorentz Invariance and Quantum Gravity Models  

NASA Technical Reports Server (NTRS)

High-energy astrophysics observations provide the best possibilities to detect a very small violation of Lorentz invariance such as may be related to the structure of space-time near the Planck scale of approximately 10(exp -35) m. I will discuss here the possible signatures of Lorentz invariance violation (LIV) from observations of the spectra, polarization, and timing of gamma-rays from active galactic nuclei and gamma-ray bursts. Other sensitive tests are provided by observations of the spectra of ultrahigh energy cosmic rays and neutrinos. Using the latest data from the Pierre Auger Observatory one can already derive an upper limit of 4.5 x 10(exp -23) to the amount of LIV of at a proton Lorentz factor of approximately 2 x 10(exp 11). This result has fundamental implications for quantum gravity models. I will also discuss the possibilities of using more sensitive space based detection techniques to improve searches for LIV in the future.

Stecker, Floyd

2011-01-01

430

Consistency of cosmic-ray source abundances with explosive nucleosynthesis  

NASA Technical Reports Server (NTRS)

Certain results regarding the ratio of cosmic-ray sources (CRS) and Solar System abundances are the same as those obtained from explosive nucleosynthesis. Such a model is consistent with the fact that in the Solar System Mg, Si, and Fe are believed to be produced by explosive nucleosynthesis, whereas C and O are mainly products of other processes. The model considered explains the carbon-to-oxygen ratio in the cosmic rays.

Kozlovsky, B.; Ramaty, R.

1973-01-01

431

Cosmic Ray Ruggedness of Power Semiconductor Devices for Hybrid Vehicles  

NASA Astrophysics Data System (ADS)

Power semiconductors that are used under high voltage conditions in hybrid vehicles (HVs) are required to have a high destruction tolerance against cosmic rays as well as to meet conventional quality standards. In this paper, the failure mechanism for single event burnouts (SEB) induced by cosmic rays in insulated gate bipolar transistors (IGBTs) was investigated. Device destruction tolerance can be greatly improved by adopting an optimized device design that greatly suppresses parasitic thyristor action.

Nishida, Shuichi; Shoji, Tomoyuki; Ohnishi, Toyokazu; Fujikawa, Touma; Nose, Noboru; Ishiko, Masayasu; Hamada, Kimimori

432

Cosmic ray driven outflows from high-redshift galaxies  

Microsoft Academic Search

We study winds in high-redshift galaxies driven by a relativistic cosmic ray (proton) component in addition to the hot thermal gas component. Cosmic rays (CRs) are likely to be efficiently generated in supernova shocks inside galaxies. We obtain solutions of such CR-driven free winds in a gravitational potential of the Navarro-Frenk-White form, relevant to galaxies. CRs naturally provide the extra

Saumyadip Samui; Kandaswamy Subramanian; Raghunathan Srianand

2010-01-01

433

A benchmark for galactic cosmic ray transport codes  

NASA Technical Reports Server (NTRS)

A nontrivial analytic benchmark solution for galactic cosmic ray transport is presented for use in transport code validation. Computational accuracy for a previously-developed cosmic ray transport code is established to within one percent by comparison with this exact benchmark. Hence, solution accuracy for the transport problem is mainly limited by inaccuracies in the input spectra, input interaction databases, and the use of a straight ahead/velocity-conserving approximation.

Wilson, John W.; Townsend, Lawrence W.

1987-01-01

434

Transport of cosmic rays in the heliosphere: Theory and models  

NASA Astrophysics Data System (ADS)

A complete, self-consistent description of cosmic ray transport in the heliosphere remains a pipe-dream. Recent progress towards such an ultimate modulation model has, however, indeed been made. More complex transport models have been implemented where traditionally independent models have been coupled in order to present a more realistic description of heliospheric modulation (for example, coupling a cosmic ray transport model with a MHD modeled heliospheric environment). Results from such hybridized models will be presented and critically evaluated.

Strauss, Du Toit; Ferreira, Stefan; Potgieter, Marius

435

Observations of Ultra-High Energy Cosmic Rays  

E-print Network

The status of measurements of the arrival directions, mass composition and energy spectrum of cosmic rays above 3 x 10^18 eV (3 EeV) is reviewed using reports presented at the 29th International Cosmic Ray Conference held in Pune, India, in August 2005. The paper is based on a plenary talk given at the TAUP2005 meeting in Zaragoza, 10 - 14 September 2005.

A A Watson

2005-11-29

436

High energy cosmic rays from AGN and the GZK cutoff  

E-print Network

Based on a model for the emission of high energy cosmic rays from AGN (Active Galactic Nuclei) that has been proposed by the author, he reviews the status of the GZK cutoff and the correlation of high energy cosmic ray sources with AGN locations in the existing data. The determination of mass for the incident particles seems to be a key factor, and a suggestion for doing that has been made in this article.

Yukio Tomozawa

2008-02-20

437

Cosmic ray antimatter: is it primary or secondary  

SciTech Connect

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

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

1981-04-01

438

Cosmogenic neutrinos from cosmic ray interactions with extragalactic infrared photons  

SciTech Connect

We discuss the production of cosmogenic neutrinos on extragalactic infrared photons in a model of its cosmological evolution. The relative importance of these infrared photons as a target for proton interactions is significant, especially in the case of steep injection spectra of the ultrahigh energy cosmic rays. For an E{sup -2.5} cosmic ray injection spectrum, for example, the event rate of neutrinos of energy above 1 PeV is more than doubled.

Stanev, Todor; De Marco, Daniel; Malkan, M.A.; Stecker, F.W. [Bartol Research Institute, University of Delaware, Newark, Delaware 19716 (United States); Department of Physics and Astronomy, University of California, Los Angeles, California 90095 (United States); NASA Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States)

2006-02-15

439

Cosmic ray antimatter: Is it primary or secondary?  

NASA Technical Reports Server (NTRS)

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

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

1981-01-01

440

The effect of cosmic rays on thunderstorm electricity  

NASA Technical Reports Server (NTRS)

The inflow of charges of small ions, formed by cosmic rays, into thunderstorm cells is estimated on the basis of rocket measurements of ionic concentrations below 90 km. Out of the two processes that form the thunderstorm charge (generation and separation of charges), the former is supposed to be caused by cosmic rays, and the nature of separation is assumed to be the same as in other thunderstorm theories.

Bragin, Y. A.

1975-01-01

441

Benchmark for galactic cosmic-ray transport codes  

SciTech Connect

A nontrivial analytic benchmark solution for galactic cosmic ray transport is presented for use in transport code validation. Computational accuracy for a previously-developed cosmic ray transport code is established to within one percent by comparison with this exact benchmark. Hence, solution accuracy for the transport problem is mainly limited by inaccuracies in the input spectra, input interaction databases, and the use of a straight ahead/velocity-conserving approximation. 9 references.

Wilson, J.W.; Townsend, L.W.

1988-01-01

442

DE-EXCITATION NUCLEAR GAMMA-RAY LINE EMISSION FROM LOW-ENERGY COSMIC RAYS IN THE INNER GALAXY  

SciTech Connect

Recent observations of high ionization rates of molecular hydrogen in diffuse interstellar clouds point to a distinct low-energy cosmic-ray component. Supposing that this component is made of nuclei, two models for the origin of such particles are explored and low-energy cosmic-ray spectra are calculated, which, added to the standard cosmic-ray spectra, produce the observed ionization rates. The clearest evidence of the presence of such low-energy nuclei between a few MeV nucleon{sup -1} and several hundred MeV nucleon{sup -1} in the interstellar medium would be a detection of nuclear {gamma}-ray line emission in the range E {sub {gamma}} {approx} 0.1-10 MeV, which is strongly produced in their collisions with the interstellar gas and dust. Using a recent {gamma}-ray cross section compilation for nuclear collisions, {gamma}-ray line emission spectra are calculated alongside the high-energy {gamma}-ray emission due to {pi}{sup 0} decay, the latter providing normalization of the absolute fluxes by comparison with Fermi-LAT observations of the diffuse emission above E {sub {gamma}} = 0.1 GeV. Our predicted fluxes of strong nuclear {gamma}-ray lines from the inner Galaxy are well below the detection sensitivities of the International Gamma-Ray Astrophysics Laboratory, but a detection, especially of the 4.4 MeV line, seems possible with new-generation {gamma}-ray telescopes based on available technology. We also predict strong {gamma}-ray continuum emission in the 1-8 MeV range, which, in a large part of our model space for low-energy cosmic rays, considerably exceeds the estimated instrument sensitivities of future telescopes.

Benhabiles-Mezhoud, H.; Kiener, J.; Tatischeff, V. [Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse, CNRS-IN2P3 and Universite Paris-Sud, F-91405 Orsay Campus (France)] [Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse, CNRS-IN2P3 and Universite Paris-Sud, F-91405 Orsay Campus (France); Strong, A. W., E-mail: Jurgen.Kiener@csnsm.in2p3.fr [Max-Planck Institut fuer extraterrestrische Physik, D-85748 Garching (Germany)

2013-02-15

443

SLOW DIFFUSION OF COSMIC RAYS AROUND A SUPERNOVA REMNANT  

SciTech Connect

We study the escape of cosmic-ray protons accelerated at a supernova remnant (SNR). We are interested in their propagation in the interstellar medium (ISM) after they leave the shock neighborhood where they are accelerated, but when they are still near the SNR with their energy density higher than that in the average ISM. Using Monte Carlo simulations, we found that the cosmic rays with energies of {approx}< TeV excite Alfven waves around the SNR on a scale of the SNR itself if the ISM is highly ionized. Thus, even if the cosmic rays can leave the shock, scattering by the waves prevents them from moving further away from the SNR. The cosmic rays form a slowly expanding cosmic-ray bubble, and they spend a long time around the SNR. This means that the cosmic rays cannot actually escape from the SNR until a fairly late stage of the SNR evolution. This is consistent with some results of Fermi and H.E.S.S. observations.

Fujita, Yutaka; Ohira, Yutaka; Takahara, Fumio [Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043 (Japan)

2010-04-01

444

Ultra-heavy cosmic rays: Theoretical implications of recent observations  

NASA Technical Reports Server (NTRS)

Extreme ultraheavy cosmic ray observations (Z greater or equal 70) are compared with r-process models. A detailed cosmic ray propagation calculation is used to transform the calculated source distributions to those observed at the earth. The r-process production abundances are calculated using different mass formulae and beta-rate formulae; an empirical estimate based on the observed solar system abundances is used also. There is the continued strong indication of an r-process dominance in the extreme ultra-heavy cosmic rays. However it is shown that the observed high actinide/Pt ratio in the cosmic rays cannot be fit with the same r-process calculation which also fits the solar system material. This result suggests that the cosmic rays probably undergo some preferential acceleration in addition to the apparent general enrichment in heavy (r-process) material. As estimate also is made of the expected relative abundance of superheavy elements in the cosmic rays if the anomalous heavy xenon in carbonaceous chondrites is due to a fissioning superheavy element.

Blake, J. B.; Hainebach, K. L.; Schramm, D. N.; Anglin, J. D.

1977-01-01

445

The origin of galactic cosmic rays  

NASA Astrophysics Data System (ADS)

Initial discovery of Cosmic Rays (CRs) dates back to a century ago (1912). Their identification as particles rather than radiation dates to about 20 years later and in 20 more years also the first suggestion that they were associated with SNRs was in place. The basic mechanism behind their acceleration was suggested almost 40 years ago. Much work has been done since then with regard to the aim of proving that both the acceleration mechanism and site are well-understood, but no definite proof has been obtained: in spite of impressive progress of both theory and observations, the evidence in support of the commonly accepted interpretation is only circumstantial. In the following, I will try to make the point on where we stand in terms of how our theories confront with data. I will review recent progress on the subject and try pointing the avenues to pursue in order to gather new proofs, if not a smoking gun evidence of the origin of Galactic CRs.

Amato, Elena

2014-05-01

446

Propagation of cosmic rays into diffuse clouds  

E-print Network

We study the capability of low-energy cosmic rays (CR) to penetrate into diffuse clouds when they move from the hot ionized plasma to a cool cloud embedded in that plasma. The spectrum of CR inside a cloud can be remarkably different from the the one present in the hot interstellar medium because when CRs pass through a dense cloud of matter, they suffer energy losses due to ionization and nuclear interactions. Hence there is a net flux of CRs towards the cloud that can excite Alfv\\'en waves. In turn, self-excited Alfv\\'en waves enhances the diffusion of CRs near the edge of the cloud, forcing CRs to spend more time in this layer and increasing the amount of energy losses. The final effect is that the flux of CR entering into the cloud is strongly suppressed below an energy threshold whose value depends on ambient parameters. For the first time we use the full kinetic theory to describe this problem, coupling CRs and Alfv\\'en waves through the streaming instability, and including the damping of the waves due ...

Morlino, Giovanni

2014-01-01

447

Solution to the cosmic ray anisotropy problem.  

PubMed

In the standard diffusive picture for transport of cosmic rays (CRs), a gradient in the CR density induces a typically small, dipolar anisotropy in their arrival directions. This is being widely advertised as a tool for finding nearby sources. However, the predicted dipole amplitude at TeV and PeV energies exceeds the measured one by almost 2 orders of magnitude. Here, we critically examine the validity of this prediction, which is based on averaging over an ensemble of turbulent magnetic fields. We focus on (1)the deviations of the dipole in a particular random realization from the ensemble average, and (2)the possibility of a misalignment between the regular magnetic field and the CR gradient. We find that if the field direction and the gradient direction are close to ?90, the dipole amplitude is considerably suppressed and can be reconciled with observations, which sheds light on a long-standing problem. Furthermore, we show that the dipole direction in general does not coincide with the gradient direction, thus hampering the search for nearby sources. PMID:25635539

Mertsch, Philipp; Funk, Stefan

2015-01-16

448

Cosmic ray transport in MHD turbulence  

E-print Network

Numerical simulations shed light onto earlier not trackable problem of magnetohydrodynamic (MHD) turbulence. They allowed to test the predictions of different models and choose the correct ones. Inevitably, this progress calls for revisions in the picture of cosmic ray (CR) transport. It also shed light on the problems with the present day numerical modeling of CR. In this paper we focus on the analytical way of describing CR propagation and scattering, which should be used in synergy with the numerical studies. In particular, we use recently established scaling laws for MHD modes to obtain the transport properties for CRs. We include nonlinear effects arising from large scale trapping, to remove the 90 degree divergence. We determine how the efficiency of the scattering and CR mean free path depend on the characteristics of ionized media, e.g. plasma $\\beta$, Coulomb collisional mean free path. Implications for particle transport in interstellar medium and solar corona are discussed. We also examine the perpendicular transport of CRs. Perpendicular transport depends on the comparison of parallel mean free path and the injection scale of the turbulence, as well as the Alfv\\'enic Mach number. Normal turbulence does not allow subdiffusion unless there are slab waves. The critical scale below which subdiffusion applies is provided. These results can be used to compare with the numerical calculations, provided that these calculations use the structure of magnetic field which is consistent with the numerical studies of MHD turbulence.

Huirong Yan; A. Lazarian

2007-12-23

449

Solution to the Cosmic Ray Anisotropy Problem  

NASA Astrophysics Data System (ADS)

In the standard diffusive picture for transport of cosmic rays (CRs), a gradient in the CR density induces a typically small, dipolar anisotropy in their arrival directions. This is being widely advertised as a tool for finding nearby sources. However, the predicted dipole amplitude at TeV and PeV energies exceeds the measured one by almost 2 orders of magnitude. Here, we critically examine the validity of this prediction, which is based on averaging over an ensemble of turbulent magnetic fields. We focus on (1) the deviations of the dipole in a particular random realization from the ensemble average, and (2) the possibility of a misalignment between the regular magnetic field and the CR gradient. We find that if the field direction and the gradient direction are close to 90 , the dipole amplitude is considerably suppressed and can be reconciled with observations, which sheds light on a long-standing problem. Furthermore, we show that the dipole direction in general does not coincide with the gradient direction, thus hampering the search for nearby sources.

Mertsch, Philipp; Funk, Stefan

2015-01-01

450

Cosmic ray spectrum from diffusive shock acceleration  

NASA Astrophysics Data System (ADS)

It is now well established that cosmic rays (CRs) are accelerated at collisionless shocks through diffusive shock acceleration. However, some key physical processes, such as thermal leakage injection, self-excitation and dissipation of waves, and resonant scatterings of particles by those waves are nonlinear and not fully understood yet. Hence it is not possible to make precise quantitative predictions for the particle spectrum accelerated at shocks from first principles. If the fraction of particles injected into the CR population is smaller than 10-4, the CR acceleration efficiency is low and so the test-particle solutions are justified. At moderately strong shocks ( M 0?5) with higher injection fractions, the shock structure is significantly modified by nonlinear feedback of CRs. According to time-dependent kinetic simulations of CR modified shocks, the precursor and subshock transition approach a time-asymptotic state, and then evolve in an approximately self-similar fashion, depending only on the similarity variable, x/( u s t). During this self-similar stage, the CR spectrum at the subshock maintains a characteristic form as it evolves: the sum of two power-laws with the slopes determined by the subshock and total compression ratios, along with an exponential cutoff at the highest accelerated momentum.

Kang, Hyesung; Ryu, Dongsu

2011-11-01

451

Relativistic cosmic rays and corotating interaction regions  

NASA Technical Reports Server (NTRS)

The relationships between relativistic galactic cosmic ray intensity variations and corotating interaction regions (CIRs) are examined. Times of CIRs overtaking the earth as indicated by Pioneer 10 and 11 plasma and field observations are compared with nucleonic intensities recorded at the Thule and McMurdo polar stations in a superposed epoch analysis, with the centers of the CIR as zero days. Results indicate a decrease in intensity around the zero days, as well as a maximum around the ninth day and a general upward trend from days -13 to 13. Further examination reveals the observed features to be present only for those CIR- associated streams in which a neutral sheet is embedded. In contrast, superposed epoch analysis of the geomagnetic Ap index with respect to CIR epochs reveals CIRs both with and without neutral sheets to produce geomagnetic storms, although the peak increase in Ap index is greater for neutral-sheet-associated CIRs. Results suggest that the CIRs modulate high-energy particle intensities by means of drifts related to neutral sheets, although diffusion effects cannot yet be ruled out.

Duggal, S. P.; Pomerantz, M. A.; Tsao, C. H.; Tsurutani, B. T.; Smith, E. J.

1981-01-01

452

Comments on cosmic ray research in Brazil  

NASA Astrophysics Data System (ADS)

Cosmic Rays (CR) have been studied since their discovery by Victor Hess in the years 1911-1913. Interestingly, research in Physics in Brazil started with experiments on CR. Bernhard Gross (INT/Rio), Gleb Wataghin and Giuseppe Occhialini (USP) carried out their investigations on CR in Brazil in the 30's. Franz X. Roser worked with V. Hess (Nobel Prize, 1936) and Cesar Lattes collaborated with Cecil Powell (Nobel Prize, 1950). Nowadays, most of CR research in Brazil is conducted by the Pierre Auger Project. Nevertheless, there is an enormous lack of information on the effects of CR in matter, particularly in organic and biological materials, which motivates measurements of relevant physicochemical data, such as parameters of crystalline structure modifications, sputtering yields and cross sections for inducing associative or dissociative processes of atoms, molecules and molecular fragments. A fascinating question about CR is whether they are/were one of the agents responsible for the transformation of inorganic into organic material, synthesizing pre-biotic molecules in the whole Universe. The physicochemical effects of CR analogues in condensed gases, analyzed by Mass Spectrometry and Infrared Spectroscopy - subject of our own work on CR - are discussed at the end of this article.

da Silveira, Enio F.

2013-05-01

453

Development of cosmic ray hardened power MOSFET's  

NASA Astrophysics Data System (ADS)

Developmental power DMOS (double-diffused metal-oxide-semiconductor) FETs were thoroughly characterized in a simulated cosmic-ray environment using heavy ions at the Brookhaven National Laboratory's tandem Van de Graaff accelerator facility. The primary failure mode encountered on FETs in this environment was susceptibility to single-event burnout. Burnout of the power DMOS FET was catastrophic. Another failure mode was single-event gate rupture. Although gate rupture is not as severe as burnout, its long-term effects are not known. Single-event gate rupture causes performance degradation due to increased gate leakage current. An increase in current can pose serious problems for applications that cannot compensate for the added performance degradation. Long-term reliability of the gate oxide may be affected, resulting in premature device failure. Numerous processing lots were fabricated to verify experimentally that each failure mode could be successfully minimized. Test results have shown that an n-channel, 150-V DMOS FET survived exposures to ions with linear energy transfers up to 80 MeV-sq cm/mg. Hardening approaches are discussed, including their advantages and disadvantages in relation to the FET's performance.

Titus, Jeffrey L.; Jamiolkowski, Linda S.; Wheatley, C. Frank

1989-12-01

454

Calibration of the Galactic Cosmic Ray Flux  

NASA Technical Reports Server (NTRS)

We report first Xe data on the cross-calibration of I-129-Xe-129(sub n) ages with conventional CRE ages, a method which is expected to provide information on the long-term constancy of the galactic cosmic ray (GCR) flux. We studied isotopic signatures of Xe released in stepwise heating, decomposition and melting of troilites in the Cape York iron meteorite to identify isotopic shifts in Xe-129 and Xe-131 due to neutron capture in Te-128 and Te-130. We also resolve components due to extinct 129I, spallation and fission Xe. There has recently been much speculation on the constancy of GCR over long time scales, as may be inferred from iron meteorites. If GCRs originate from supernova events, this provides the basis for postulating increased fluxes at locations with higher than average densities of supernovae, specifically in OB-associations. The solar system at present appears to be inside a local bubble between spiral arms and may experience an increased GCR flux.

Mathew, K. J.; Marti, K.

2004-01-01

455

Space Weather, Cosmic Rays, and Satellite Anomalies  

NASA Astrophysics Data System (ADS)

Results are presented of the Satellite Anomaly Project, which aims to improve the methods of safeguarding satellites in the Earths magnetosphere from the negative effects of the space environment. Anomaly data from the USSR and Russian Kosmos series satellites in the period 1971-1999 are combined into one database, together with similar information on other spacecraft. This database contains, beyond the anomaly information, various characteristics of space weather: geomagnetic activity indices (Ap, AE and Dst), fluxes and fluencies of electrons and protons at different energies, high energy cosmic ray variations and other solar, interplanetary and solar wind data. A comparative analysis of the distribution of each of these parameters relative to satellite anomalies was carried out for the total number of anomalies (about 6000 events), and separately for high altitude orbit satellites ( 5000 events) and low altitude (about 800 events). No relation was found between low and high altitude satellite anomalies. Daily numbers of satellite anomalies, averaged by a superposed epoch method around sudden storm commencements and proton event onsets for high (>1500 km) and low (<1500 km) altitude orbits revealed a big difference in behavior. Satellites were divided into several groups according to their orbital characteristics (altitude and inclination). The relation of satellite anomalies to the environmental parameters was found t