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Sample records for cosmic ray detection

  1. Radar Detection of Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Myers, Isaac

    2012-03-01

    Progress in the study of high energy cosmic ray physics is limited by low flux. In order to collect substantial statistics above 10^19 eV, the two largest ground arrays currently in operation cover 800 km^2 (Telescope Array, Utah) and 3000 km^2 (Auger Observatory, Argentina). The logistics and cost of an order-of-magnitude increase in ground array aperture is prohibitive. In the literature, radar detection experiments have been proposed but substantial results have not been reported. We have deployed a low-power (1500 W) bistatic radar facility overlapping the Telescope Array (TA) in Delta, Utah. Data acquisition systems for the radar receivers were developed in parallel. This system has taught us a great deal, but our current focus is building and deploying a 40 kW transmitter and new high-gain transmitting antenna. Theoretical simulations of CR air shower scattering of radar show that coincidences with the ground array should be detected with this new system. An FCC license for the new transmitter/antenna has been obtained. Systems monitoring and data logging systems, as well as a new, intelligent self-triggered DAQ continue to be developed. We hope to deploy the self-triggered DAQ during the first few months of 2012 and complete the transmitte

  2. Research Concerning Detection of Cosmic Rays

    NASA Astrophysics Data System (ADS)

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

    2010-02-01

    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. )

  3. Detecting EHE Cosmic Rays Using Cherenkov Light

    NASA Astrophysics Data System (ADS)

    Bergman, Douglas

    2011-04-01

    Cherenkov light has been used to detect gamma rays in the TeV energy range using an imaging technique and cosmic rays in the PeV energy range using a non-imaging technique. We would like to extend the use of the non-imaging technique up to nearly 1 EeV. At these energies the technique can be used in conjunction with fluorescence detection of cosmic rays, allowing for hybrid reconstruction of shower geometries and cross calibration of energy scales. We envision using an array of Cherenkov detectors as part of the Telescope Array (TA) Low Energy extension (TALE), extending the energy range of the detector down to the Knee of the cosmic ray energy spectrum.

  4. Radar detection of ultra high energy cosmic rays

    NASA Astrophysics Data System (ADS)

    Myers, Isaac J.

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

  5. Student Projects in Cosmic Ray Detection

    ERIC Educational Resources Information Center

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

    2009-01-01

    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…

  6. Student Projects in Cosmic Ray Detection

    ERIC Educational Resources Information Center

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

    2009-01-01

    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

  7. The Renaissance of Radio Detection of Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Huege, Tim

    2014-10-01

    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.

  8. Cosmic Ray Inspection and Passive Tomography for SNM Detection

    SciTech Connect

    Armitage, John; Oakham, Gerald; Bryman, Douglas; Cousins, Thomas; Noeel, Scott; Gallant, Grant; Jason, Andrew; Jonkmans, Guy; Stocki, Trevor J.; Waller, David

    2009-12-02

    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.

  9. Field Programmable Gate Arrays—Detecting Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Dasgupta, S.; Cussans, D.

    2015-07-01

    Field Programmable Gate Arrays (FPGAs) are finding extensive application in instrumentation for particle physics experiments. A table-top framework is developed using FPGA-based hardware to detect the coincidence of signals produced by cosmic rays in multiple detectors. The rates of the detector signals and coincidence output are also measured. The logic is programmed inside an FPGA mounted on a Xilinx evaluation board. Control and data readout are carried out using IPbus, a gigabit Ethernet-based protocol developed as part of upgrading the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) . The framework is appropriate for introducing students to FPGA-based instrumentation and providing them with a practical experience of working with such hardware.

  10. Detection of cosmic ray tracks using scintillating fibers and position sensitive multi-anode photomultipliers

    SciTech Connect

    Atac, M.; Streets, J.; Wilcer, N.

    1998-02-01

    This experiment demonstrates detection of cosmic ray tracks by using Scintillating fiber planes and multi-anode photomultipliers (MA-PMTs). In a laboratory like this, cosmic rays provide a natural source of high-energy charged particles which can be detected with high efficiency and with nanosecond time resolution.

  11. ESA's Integral detects closest cosmic gamma-ray burst

    NASA Astrophysics Data System (ADS)

    2004-08-01

    5 August 2004 A gamma-ray burst detected by ESA's Integral gamma-ray observatory on 3 December 2003 has been thoroughly studied for months by an armada of space and ground-based observatories. Astronomers have now concluded that this event, called GRB 031203, is the closest cosmic gamma-ray burst on record, but also the faintest. This also suggests that an entire population of sub-energetic gamma-ray bursts has so far gone unnoticed... Gamma ray burst model hi-res Size hi-res: 22 KB Credits: CXC/M. Weiss Artist impression of a low-energy gamma-ray burst This illustration describes a model for a gamma-ray burst, like the one detected by Integral on 3 December 2003 (GRB 031203). A jet of high-energy particles from a rapidly rotating black hole interacts with surrounding matter. Observations with Integral on 3 December 2003 and data on its afterglow, collected afterwards with XMM-Newton, Chandra and the Very Large Array telescope, show that GRB 031203 radiated only a fraction of the energy of normal gamma-ray bursts. Like supernovae, gamma-ray bursts are thought to be produced by the collapse of the core of a massive star. However, while the process leading to supernovae is relatively well understood, astronomers still do not know what happens when a core collapses to form a black hole. The discovery of 'under-energetic' gamma-ray bursts, like GRB 031203, should provide valuable clues as to links between supernovae, black holes and gamma-ray bursts. Lo-res JPG (22 Kb) Hi-res TIFF (5800 Kb) Cosmic gamma-ray bursts (GRBs) are flashes of gamma rays that can last from less than a second to a few minutes and occur at random positions in the sky. A large fraction of them is thought to result when a black hole is created from a dying star in a distant galaxy. Astronomers believe that a hot disc surrounding the black hole, made of gas and matter falling onto it, somehow emits an energetic beam parallel to the axis of rotation. According to the simplest picture, all GRBs should emit similar amounts of gamma-ray energy. The fraction of it detected at Earth should then depend on the 'width' (opening angle) and orientation of the beam as well as on the distance. The energy received should be larger when the beam is narrow or points towards us and smaller when the beam is broad or points away from us. New data collected with ESA's high energy observatories, Integral and XMM-Newton, now show that this picture is not so clear-cut and that the amount of energy emitted by GRBs can vary significantly. "The idea that all GRBs spit out the same amount of gamma rays, or that they are 'standard candles' as we call them, is simply ruled out by the new data," said Dr Sergey Sazonov, from the Space Research Institute of the Russian Academy of Sciences, Moscow (Russia) and the Max-Planck Institute for Astrophysics, Garching near Munich (Germany). Sazonov and an international team of researchers studied the GRB detected by Integral on 3 December 2003 and given the code-name of GRB 031203. Within a record 18 seconds of the burst, the Integral Burst Alert System had pinpointed the approximate position of GRB 031203 in the sky and sent the information to a network of observatories around the world. A few hours later one of them, ESA's XMM-Newton, determined a much more precise position for GRB 031203 and detected a rapidly fading X-ray source, which was subsequently seen by radio and optical telescopes on the ground. This wealth of data allowed astronomers to determine that GRB 031203 went off in a galaxy less than 1300 million light years away, making it the closest GRB ever observed. Even so, the way in which GRB 031203 dimmed with time and the distribution of its energy were not different from those of distant GRBs. Then, scientists started to realise that the concept of the 'standard candle' may not hold. "Being so close should make GRB 031203 appear very bright, but the amount of gamma-rays measured by Integral is about one thousand times less than what we would normally expect from a GRB," Sazonov said. A burst of gamma rays observed in 1998 in a closer galaxy appeared even fainter, about one hundred times less bright than GRB 031203. Astronomers, however, could not conclusively tell whether that was a genuine GRB because the bulk of its energy was emitted mostly as X-rays instead of gamma-rays. The work of Sazonov's team on GRB 031203 now suggests that intrinsically fainter GRBs can indeed exist. A team of US astronomers, coordinated by Alicia Soderberg from the California Institute of Technology, Pasadena (USA), studied the 'afterglow' of GRB 031203 and gave further support to this conclusion. The afterglow, emitted when a GRB's blastwave shocks the diffuse medium around it, can last weeks or months and progressively fades away. Using NASA's Chandra X-ray Observatory, Soderberg and her team saw that the X-ray brightness of the afterglow was about one thousand times fainter than that of typical distant GRBs. The team's observations with the Very Large Array telescope of the National Radio Astronomy Observatory in Socorro (USA) also revealed a source dimmer than usual. Sazonov and Soderberg explain that their teams looked carefully for signs that GRB 031203 could be tilted in such a way that most of its energy would escape Integral's detection. However, as Sazonov said, "the fact that most of the energy that we see is emitted in the gamma-ray domain, rather than in the X-rays, means that we are seeing the beam nearly on axis." It is, therefore, unlikely that much of its energy output can go unnoticed. This discovery suggests the existence of a new population of GRBs much closer but also dimmer than the majority of those known so far, which are very energetic but distant. Objects of this type may also be very numerous and thus produce more frequent bursts. The bulk of this population has so far escaped our attention because it lies at the limit of detection with past and present instruments. Integral, however, may be just sensitive enough to reveal a few more of them in the years to come. These could be just the tip of the iceberg and future gamma-ray observatories, such as the planned NASA's Swift mission, should be able to extend this search to a much larger volume of the Universe and find many more sub-energetic GRBs. Notes for editors The results of this investigation are presented in two articles that have appeared in today's issue of the scientific journal Nature. One of them, by S. Sazonov, A. Lutovinov and R. Sunyaev, is entitled "An apparently normal gamma-ray burst with unusually low luminosity". The other, entitled "The sub-energetic GRB 031203 as a cosmic analogue to GRB 980425", is signed by A. Soderberg, S. Kulkarni, E. Berger, D. Fox, M. Sako, D. Frail, A. Gal-Yam, D. Moon, S. Cenko, S. Yost, M. Phillips, E. Persson, W. Freedman, P. Wyatt, R. Jayawardhana and D. Paulson. The original announcement of the Integral detection of GRB 031203 was made by D. Goetz, S. Mereghetti, M. Beck, J. Borkowski and N. Mowlavi, via the Circular Service of the GRB Co-ordinates Network. More about Integral The International Gamma Ray Astrophysics Laboratory (Integral) is the first space observatory that can simultaneously observe celestial objects in gamma rays, X-rays and visible light. Integral was launched on a Russian Proton rocket on 17 October 2002 into a highly elliptical orbit around Earth. Its principal targets include regions of the galaxy where chemical elements are being produced and compact objects, such as black holes. For more information about Integral please see: http://www.esa.int/esaSC/spk.html More about XMM-Newton ESA's XMM-Newton can detect more X-ray sources than any previous satellite and is helping to solve many cosmic mysteries of the violent Universe, from black holes to the formation of galaxies. It was launched on 10 December 1999, using an Ariane-5 rocket, from French Guiana. It is expected to return data for a decade. XMM-Newton's high-tech design uses over 170 wafer-thin cylindrical mirrors spread over three telescopes. Its orbit takes it almost a third of the way to the Moon, so that astronomers can enjoy long, uninterrupted views of celestial objects. For more information about XMM-Newton please see: http://www.esa.int/esaSC/spk.html More about Chandra NASA's Marshall Space Flight Center, Huntsville, Alabama, manages the Chandra programme for the Office of Space Science, NASA Headquarters, Washington DC, USA. Northrop Grumman of Redondo Beach, California, formerly TRW Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Massachusetts. For more information about Chandra please see: http://chandra.harvard.edu/about More about the Very Large Array The Very Large Array (VLA) is a research facility of the United States National Science Foundation. With 27 dish antennas, each 25 metres in diameter, working together as a single imaging instrument, it is the most versatile and most widely used radio telescope in the world. Dedicated in 1980, the VLA has been used by thousands of scientists and has contributed valuable new information to nearly every specialty within astronomy. In 1997, the VLA made the first-ever detection of a gamma-ray burst afterglow at radio wavelengths, and has been at the forefront of gamma-ray burst afterglow research since.

  12. Hoping to indirectly detect Dark Matter with cosmic rays

    NASA Astrophysics Data System (ADS)

    Cirelli, Marco

    2010-11-01

    Dark Matter constitutes more that 80% of the total amount of matter in the Universe, yet almost nothing is known about its nature. A powerful investigation technique is that of searching for the products of annihilations of Dark Matter particles in the galactic halo, on top of the ordinary cosmic rays. Recent data from the PAMELA and FERMI satellites and a number of balloon experiment have reported unexpected excesses in the measured fluxes of cosmic rays. Are these the first direct evidences for Dark Matter? If yes, which DM models and candidates can explain these anomalies (in terms of annihilations) and what do they imply for future searches? What are the constraints from gamma rays measurements and cosmology? [Report number: Saclay T-10/098, CERN-PH-TH/2010-183].

  13. FPGA Based Wavelet Trigger in Radio Detection of Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Szadkowski, Zbigniew; Szadkowska, Anna

    2014-12-01

    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.

  14. Exploring results of the possibility on detecting cosmic ray particles by acoustic way

    NASA Technical Reports Server (NTRS)

    Jiang, Y.; Yuan, Y.; Li, Y.; Chen, D.; Zheng, R.; Song, J.

    1985-01-01

    It has been demonstrated experimentally and theoretically that high energy particles produce detectable sounds in water. However, no one has been able to detect an acoustic signal generated by a high energy cosmic ray particle in water. Results show that transient ultrasonic signals in a large lake or reservoir are fairly complex and that the transient signals under water may arise mainly from sound radiation from microbubbles. This field is not explored in detail. Perhaps, the sounds created by cosmic ray particles hide in these ultrasonic signals. In order to develop the technique of acoustic detection, it is most important to make a thorough investigation of these ultrasonic signals in water.

  15. Application of thermoluminescence for detection of cascade shower 2: Detection of cosmic ray cascade shower at Mount Fuji

    NASA Technical Reports Server (NTRS)

    Akashi, M.; Kawaguchi, S.; Watanabe, Z.; Misaki, A.; Niwa, M.; Okamoto, Y.; Fujinaga, T.; Ichimura, M.; Shibata, T.; Dake, S.

    1985-01-01

    The results of a thermoluminescence (TL) chamber exposed at Mt. Fuji during Aug. '83 - Aug. '84 are reported. The TL signal induced by cosmic ray shower is detected and compared with the spot darkness of X-ray film exposed at the same time.

  16. Radio detection of cosmic ray air showers in the digital era

    NASA Astrophysics Data System (ADS)

    Huege, Tim

    2016-03-01

    In 1965 it was discovered that cosmic ray air showers emit impulsive radio signals at frequencies below 100 MHz. After a period of intense research in the 1960s and 1970s, however, interest in the detection technique faded almost completely. With the availability of powerful digital signal processing techniques, new attempts at measuring cosmic ray air showers via their radio emission were started at the beginning of the new millennium. Starting with modest, small-scale digital prototype setups, the field has evolved, matured and grown very significantly in the past decade. Today's second-generation digital radio detection experiments consist of up to hundreds of radio antennas or cover areas of up to 17 km2. We understand the physics of the radio emission in extensive air showers in detail and have developed analysis strategies to accurately derive from radio signals parameters which are related to the astrophysics of the primary cosmic ray particles, in particular their energy, arrival direction and estimators for their mass. In parallel to these successes, limitations inherent in the physics of the radio signals have also become increasingly clear. In this article, we review the progress of the past decade and the current state of the field, discuss the current paradigm of the radio emission physics and present the experimental evidence supporting it. Finally, we discuss the potential for future applications of the radio detection technique to advance the field of cosmic ray physics.

  17. Detection techniques of radio emission from ultra high energy cosmic rays

    NASA Astrophysics Data System (ADS)

    Morris, Chad M.

    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.

  18. Cosmic Ray Physics at a Community College: Assembly, Detection and Measurement

    NASA Astrophysics Data System (ADS)

    Fan, Sewan; Davis, Scott; Osornio, Leo; Haag, Brooke

    2012-03-01

    During an in-depth eight week summer research program at Hartnell Community College in Salinas, CA, we constructed two complementary experimental systems to measure cosmic rays. One system used NIM electronic modules configured for coincidence measurement. To detect the comic rays, two photomultiplier tubes each coupled to plastic scintillator paddles were assembled. The other system was build from a circuit board designed by the LBL Cosmic Ray Project. Extensive prototype and diagnosis for this board were done prior to final soldering of the parts. The dependence of the cosmic ray flux on the separation between scintillator paddles was measured and showed reasonable agreement with the accepted value. The flux dependence on the square of the cosine of the polar angle was also tested, and our result showed closely the expected cosine behavior using the NIM setup. As for the LBL Lab circuit board, it was difficult to obtain reliable coincidence counts for large polar angles probably due to the lack of an adjustable discriminator control. This was compensated for by operating the detectors at a lower high voltage which reduced the random counts, without affecting signals. This strategy gave a more reliable cosmic ray flux result using the Berkeley Lab circuit board.

  19. Detection of high energy cosmic rays with the resonant gravitational wave detectors NAUTILUS and EXPLORER

    NASA Astrophysics Data System (ADS)

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

    2008-11-01

    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 expected values 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 ˜670 K, corresponding to ˜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.

  20. Origin of cosmic rays

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1975-01-01

    Based on recent observations of the galactic gas and gamma ray distributions, the galactic cosmic ray distribution is deduced. This distribution is identical to that of supernova remnants (within experimental error), strongly supporting the hypothesis that most observed cosmic rays are produced by supernovas in our own galaxy. The average age of the cosmic ray sources is suggested, from the character of their distribution, to be about 30 million years.

  1. Detection and imaging of atmospheric radio flashes from cosmic ray air showers.

    PubMed

    Falcke, H; Apel, W D; Badea, A F; Bähren, L; Bekk, K; Bercuci, A; Bertaina, M; Biermann, P L; Blümer, J; Bozdog, H; Brancus, I M; Buitink, S; Brüggemann, M; Buchholz, P; Butcher, H; Chiavassa, A; Daumiller, K; de Bruyn, A G; de Vos, C M; Di Pierro, F; Doll, P; Engel, R; Gemmeke, H; Ghia, P L; Glasstetter, R; Grupen, C; Haungs, A; Heck, D; Hörandel, J R; Horneffer, A; Huege, T; Kampert, K-H; Kant, G W; Klein, U; Kolotaev, Y; Koopman, Y; Krömer, O; Kuijpers, J; Lafebre, S; Maier, G; Mathes, H J; Mayer, H J; Milke, J; Mitrica, B; Morello, C; Navarra, G; Nehls, S; Nigl, A; Obenland, R; Oehlschläger, J; Ostapchenko, S; Over, S; Pepping, H J; Petcu, M; Petrovic, J; Plewnia, S; Rebel, H; Risse, A; Roth, M; Schieler, H; Schoonderbeek, G; Sima, O; Stümpert, M; Toma, G; Trinchero, G C; Ulrich, H; Valchierotti, S; van Buren, J; van Cappellen, W; Walkowiak, W; Weindl, A; Wijnholds, S; Wochele, J; Zabierowski, J; Zensus, J A; Zimmermann, D

    2005-05-19

    The nature of ultrahigh-energy cosmic rays (UHECRs) at energies >10(20) eV remains a mystery. They are likely to be of extragalactic origin, but should be absorbed within approximately 50 Mpc through interactions with the cosmic microwave background. As there are no sufficiently powerful accelerators within this distance from the Galaxy, explanations for UHECRs range from unusual astrophysical sources to exotic string physics. Also unclear is whether UHECRs consist of protons, heavy nuclei, neutrinos or gamma-rays. To resolve these questions, larger detectors with higher duty cycles and which combine multiple detection techniques are needed. Radio emission from UHECRs, on the other hand, is unaffected by attenuation, has a high duty cycle, gives calorimetric measurements and provides high directional accuracy. Here we report the detection of radio flashes from cosmic-ray air showers using low-cost digital radio receivers. We show that the radiation can be understood in terms of the geosynchrotron effect. Our results show that it should be possible to determine the nature and composition of UHECRs with combined radio and particle detectors, and to detect the ultrahigh-energy neutrinos expected from flavour mixing. PMID:15902250

  2. LAT Perspectives in Detection of High Energy Cosmic Ray Electrons

    SciTech Connect

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

    2007-11-13

    The LAT science objectives and capabilities in the detection of high energy electrons in the energy range from 20 GeV to {approx}1.5 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. It is expected to collect {approx} ten million of electrons with the energy above 20 GeV for one year of observation. Precise spectrum reconstruction with collected electron statistics opens the unique opportunity to investigate several important problems such as models of IC radiation, revealing the signatures of nearby sources such as high energy cutoff in the electron spectrum, testing the propagation model, and search for KKDM particles decay through their contribution to the electron spectrum.

  3. LAT Perspectives in Detection of High Energy Cosmic Ray Electrons

    SciTech Connect

    Moiseev, Alexander; Funk, Stefan

    2007-07-12

    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.

  4. LAT Perspectives in Detection of High Energy Cosmic Ray Electrons

    NASA Technical Reports Server (NTRS)

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

    2007-01-01

    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.

  5. Cosmic x ray physics

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

    The annual progress report on Cosmic X Ray Physics for the period 1 Jan. to 31 Dec. 1990 is presented. Topics studied include: soft x ray background, new sounding rocket payload: x ray calorimeter, and theoretical studies.

  6. Cosmic x ray physics

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

    The annual progress report on Cosmic X Ray Physics is presented. Topics studied include: the soft x ray background, proportional counter and filter calibrations, the new sounding rocket payload: X Ray Calorimeter, and theoretical studies.

  7. Cosmic Ray Experiments and the Implications for Indirect Detection of Dark Matter

    NASA Technical Reports Server (NTRS)

    Mitchell, John W.; Ormes, Jonathan F.; Streitmatter, Robert E.

    2013-01-01

    Detection of cosmic-ray antiprotons was first reported by Golden et al. in 1979 and their existence was firmly established by the BESS and IMAX collaborations in the early 1990s. Increasingly precise measurements of the antiproton spectrum, most recently from BESS-Polar and PAMELA, have made it an important tool for investigating cosmic-ray transport in the galaxy and heliosphere and for constraining dark-matter models. The history of antiproton measurements will be briefly reviewed. The current status will be discussed, focusing on the results of BESS-Polar II and their implications for the possibility of antiprotons from primordial black hole evaporation. The current results of the BESS-Polar II antihelium search are also presented.

  8. Cosmic Rays in Thunderstorms

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

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

  9. Cosmic ray isotopes

    NASA Technical Reports Server (NTRS)

    Stone, E. C.

    1973-01-01

    The isotopic composition of cosmic rays is studied in order to develop the relationship between cosmic rays and stellar processes. Cross section and model calculations are reported on isotopes of H, He, Be, Al and Fe. Satellite instrument measuring techniques separate only the isotopes of the lighter elements.

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

    SciTech Connect

    Richard Maurer

    2008-09-18

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

  11. Cosmic-ray astrochemistry.

    PubMed

    Indriolo, Nick; McCall, Benjamin J

    2013-10-01

    Gas-phase chemistry in the interstellar medium is driven by fast ion-molecule reactions. This, of course, demands a mechanism for ionization, and cosmic rays are the ideal candidate as they can operate throughout the majority of both diffuse and dense interstellar clouds. Aside from driving interstellar chemistry via ionization, cosmic rays also interact with the interstellar medium in ways that heat the ambient gas, produce gamma rays, and produce light element isotopes. In this paper we review the observables generated by cosmic-ray interactions with the interstellar medium, focusing primarily on the relevance to astrochemistry. PMID:23812538

  12. The MIDAS telescope for microwave detection of ultra-high energy cosmic rays

    NASA Astrophysics Data System (ADS)

    Alvarez-Muñiz, J.; Amaral Soares, E.; Berlin, A.; Bogdan, M.; Boháčová, M.; Bonifazi, C.; Carvalho, W. R.; de Mello Neto, J. R. T.; Facal San Luis, P.; Genat, J. F.; Hollon, N.; Mills, E.; Monasor, M.; Privitera, P.; Ramos de Castro, A.; Reyes, L. C.; Richardson, M.; Rouille d'Orfeuil, B.; Santos, E. M.; Wayne, S.; Williams, C.; Zas, E.; Zhou, J.

    2013-08-01

    We present the design, implementation and data taking performance of the MIcrowave Detection of Air Showers (MIDAS) experiment, a large field of view imaging telescope designed to detect microwave radiation from extensive air showers induced by ultra-high energy cosmic rays. This novel technique may bring a tenfold increase in detector duty cycle when compared to the standard fluorescence technique based on detection of ultraviolet photons. The MIDAS telescope consists of a 4.5 m diameter dish with a 53-pixel receiver camera, instrumented with feed horns operating in the commercial extended C-Band (3.4-4.2 GHz). A self-trigger capability is implemented in the digital electronics. The main objectives of this first prototype of the MIDAS telescope - to validate the telescope design, and to demonstrate a large detector duty cycle - were successfully accomplished in a dedicated data taking run at the University of Chicago campus prior to installation at the Pierre Auger Observatory.

  13. Cosmic rays and grain alignment

    NASA Astrophysics Data System (ADS)

    Lazarian, A.; Roberge, W. G.

    1997-06-01

    The recent detection of interstellar polarization in the solid CO feature near 4.67mum shows that CO-mantled grains can be aligned in cold molecular clouds. These observations conflict with a theory of grain alignment which attributes the polarization in molecular clouds to the effects of cosmic rays: according to this theory, oblate spheroidal grains with H_2O- and CO_2-dominated ice mantles are spun up to suprathermal energies by molecular evaporation from cosmic ray impact sites, but spin-up does not occur for CO-mantled grains. Motivated by this conflict, we re-examine the effects of cosmic rays on the alignment of icy grains. We show that the systematic torques produced by cosmic rays are insufficient to cause suprathermal spin. In principle, the random torques due to cosmic rays can enhance the efficiency of Davis-Greenstein alignment by raising the grain rotational temperature. However, a significant enhancement would require cosmic ray fluxes 6-7 orders of magnitude larger than the flux in a typical cold cloud.

  14. Eleventh European Cosmic Ray Symposium

    NASA Astrophysics Data System (ADS)

    1988-08-01

    The biannual Symposium includes all aspects of cosmic ray research. The scientific program was organized under three main headings: cosmic rays in the heliosphere, cosmic rays in the interstellar and extragalactic space, and properties of high-energy interactions as studied by cosmic rays. Selected short communications out of 114 contributed papers were indexed separately for the INIS database.

  15. Cosmic Rays and Climate

    NASA Astrophysics Data System (ADS)

    Kirkby, J.

    2005-12-01

    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.

  16. Cosmic rays in astrospheres

    NASA Astrophysics Data System (ADS)

    Scherer, K.; van der Schyff, A.; Bomans, D. J.; Ferreira, S. E. S.; Fichtner, H.; Kleimann, J.; Strauss, R. D.; Weis, K.; Wiengarten, T.; Wodzinski, T.

    2015-04-01

    Context. 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. Aims: We study the cosmic ray flux in and around λ Cephei as an example for an astrosphere. The large-scale plasma flow is modeled hydrodynamically with radiative cooling. Methods: We study 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. Results: 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 the observer. Conclusions: Small-scale cosmic ray anisotropies can naturally be explained by the modulation of cosmic ray spectra in huge stellar wind cavities.

  17. Detection of ultra-high energy cosmic ray showers with a single-pixel fluorescence telescope

    NASA Astrophysics Data System (ADS)

    Fujii, T.; Malacari, M.; Bertaina, M.; Casolino, M.; Dawson, B.; Horvath, P.; Hrabovsky, M.; Jiang, J.; Mandat, D.; Matalon, A.; Matthews, J. N.; Motloch, P.; Palatka, M.; Pech, M.; Privitera, P.; Schovanek, P.; Takizawa, Y.; Thomas, S. B.; Travnicek, P.; Yamazaki, K.

    2016-02-01

    We present a concept for large-area, low-cost detection of ultra-high energy cosmic rays (UHECRs) with a Fluorescence detector Array of Single-pixel Telescopes (FAST), addressing the requirements for the next generation of UHECR experiments. In the FAST design, a large field of view is covered by a few pixels at the focal plane of a mirror or Fresnel lens. We report first results of a FAST prototype installed at the Telescope Array site, consisting of a single 200 mm photomultiplier tube at the focal plane of a 1 m2 Fresnel lens system taken from the prototype of the JEM-EUSO experiment. The FAST prototype took data for 19 nights, demonstrating remarkable operational stability. We detected laser shots at distances of several kilometers as well as 16 highly significant UHECR shower candidates.

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

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

    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.

  19. Large doppler shift in radar detection of ultra-high energy cosmic rays.

    SciTech Connect

    Underwood, D. G.; High Energy Physics

    2008-01-01

    Radar detection of cosmic ray air showers has been discussed for 60 years, but never clearly observed. The topic was reexamined by Gorham in 2001 and some serious simulations were done by Takai, who also initiated the Mariachi project utilizing commercial television transmissions as a signal source. The air showers from ultra-high energy cosmic rays are expected to generate a plasma with plasma frequency in the high VHF region. One factor limiting the received signal strength is the short ion recombination time in air at low altitude. However, a major factor which has not been the center of attention so far is the possible large Doppler shifts for non-specular reflection, and the soft transition between specular and diffuse for small objects and short time scales. We discuss recent work on receivers, and simulations of the Doppler shift. These simulations assume a very short ion recombination time in the lower atmosphere, and use an extremely simple mathematical model. A central feature of our simulations is large Doppler shift from non-moving material.

  20. Detection of the cosmic γ-ray horizon from multiwavelength observations of blazars

    SciTech Connect

    Dominguez, A.; Finke, J. D.; Prada, F.; Primack, J. R.; Kitaura, F. S.; Siana, B.; Paneque, D.

    2013-05-24

    The first statistically significant detection of the cosmic γ-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) γ-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 γ-ray observations of cosmological blazars and γ-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 γ-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. The comparison provides an estimate of the optical depth of the EBL, which allows 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.

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

    NASA Technical Reports Server (NTRS)

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

    1975-01-01

    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.

  2. Cosmic Ray Dosimetry

    NASA Astrophysics Data System (ADS)

    Si Belkhir, F.; Attallah, R.

    2010-10-01

    Radiation levels at aircraft cruising altitudes are twenty times higher than at sea level. Thus, on average, a typical airline pilot receives a larger annual radiation dose than some one working in nuclear industry. The main source of this radiation is from galactic cosmic radiation, high energy particles generated by exploding stars within our own galaxy. In this work we study cosmic rays dosimetry at various aviation altitudes using the PARMA model.

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

    PubMed

    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; Jóhannesson, G; Johnson, A S; Kamae, T; Katagiri, H; Kataoka, J; Kerr, M; Knödlseder, 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; Rainò, S; Rando, R; Razzano, M; Reposeur, T; Ritz, S; Parkinson, P M Saz; Sgrò, 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

    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

  4. Scintillator Cosmic Ray Super Telescope

    NASA Astrophysics Data System (ADS)

    González, L. X.; Valdés-Galicia, J. F.; Matsubara, Y.; Nagai, Y.; Itow, Y.; Sako, T.; López, D.; Mitsuka, G.; Munakata, K.; Kato, C.; Yasue, S.; Kosai, M.; Tsurusashi, M.; Nakamo, Y.; Shibata, S.; Takamaru, H.; Kojima, H.; Tsuchiya, H.; Watanabe, K.; Koi, T.; Fragoso, E.; Hurtado, A.; Musalem, O.

    2013-04-01

    The Scintillator Cosmic Ray Super Telescope (SciCRST) is a new experiment to detect solar neutrons, and also it is expected to work as a muon and cosmic ray detector. The SciCRST consist of 14,848 plastic scintillator bars, and it will be installed at the top of Sierra Negra volcano, Mexico, 4580 m.a.s.l. We use a prototype, called as miniSciBar, to test the hardware and software of the final experiment. In this paper, we present the status and details of the experiment, and results of the prototype.

  5. Modulation of solar cosmic rays

    NASA Technical Reports Server (NTRS)

    Fisk, L. A.

    1973-01-01

    Consideration is given to whether the modulation of low energy solar cosmic ray nuclei between the sun and earth can be so extreme that the fluxes observed at 1 AU imply (1) that the cosmic ray energy density in the solar atmosphere is comparable to the thermal energy density, and/or (2) that the cosmic ray intensity is sufficient in the solar atmosphere to produce detectable fluxes of secondary particles such as low energy positrons. It was found that such large modulation is compatible with observations, provided that the modulation occurrence is confined within a solar envelope lying within approximately 0.2 to 0.3 AU of the sun. There is, however, no compelling observational evidence to require that the modulation is this large.

  6. On the Possibility of Radar Detection of Ultra-high Energy Cosmic Ray- and Neutrino-induced Air Showers

    NASA Technical Reports Server (NTRS)

    Gorham, P.

    1999-01-01

    We show that cosmic rays air showers resulting from primaries with energies above 10(sup 19) eV should be straightforward to detect with radar ranging techniques, where the radar echoes are produced by scattering from the column of ionized air produced by the shower.

  7. Future use of silicon photomultipliers for the fluorescence detection of ultra-high-energy cosmic rays

    NASA Astrophysics Data System (ADS)

    Stephan, Maurice; Hebbeker, Thomas; Lauscher, Markus; Meurer, Christine; Niggemann, Tim; Schumacher, Johannes

    2011-10-01

    A sophisticated technique to measure extensive air showers initiated by ultra-high-energy cosmic rays is by means of fluorescence telescopes. Secondary particles of the air shower excite nitrogen molecules of the atmosphere, which emit fluorescence light when they de-excite. Due to their high photon detection efficiency (PDE) silicon photomultipliers (SiPMs) promise to increase the sensitivity of todays fluorescence telescopes which use photomultiplier tubes - for example the fluorescence detector of the Pierre Auger Observatory. On the other hand drawbacks like a small sensitive area, a strong temperature dependency and a high noise rate have to be managed. We present plans for a prototype fluorescence telescope using SiPMs and a special light collecting optical system of Winston cones to increase the sensitive area. In this context we made measurements of the relative PDE of SiPMs depending on the incident angle of light. The results agree with calculations based on the Fresnel equations. Furthermore, measurements of the brightness of the night sky are presented since this photon flux is the main background to the fluorescence signals of the extensive air showers. To compensate the temperature dependency of the SiPM, frontend electronics make use of temperature sensors and microcontrollers to directly adjust the bias-voltage according to the thermal conditions. To reduce the noise rate we study the coincidence of several SiPMs signals triggered by cosmic ray events. By summing up these signals the SiPMs will constitute a single pixel of the fluorescence telescope.

  8. K-alpha X-rays from cosmic ray oxygen. [Detection and calculation of equilibrium charge fractions

    NASA Technical Reports Server (NTRS)

    Pravdo, S. H.; Boldt, E. A.

    1975-01-01

    Equilibrium charge fractions are calculated for subrelativistic cosmic ray oxygen ions in the interstellar medium. These are used to determine the expected flux of K-alpha rays arising from atomic processes for a number of different postulated interstellar oxygen spectra. Relating these results to the diffuse X-ray background measured at the appropriate energy level suggests an observable line feature. If the flux of low energy cosmic ray oxygen is sufficiently large, K-alpha X-ray line emission from these nuclei will comprise a significant fraction of the total diffuse flux at approximately 0.6 keV. A satellite borne detector with a resolution greater than 30 percent could observe this feature if the subrelativistic interstellar cosmic ray oxygen spectrum is as large as certain theoretical estimates expressed in the text.

  9. Cosmic gamma rays

    NASA Astrophysics Data System (ADS)

    Wolfendale, A. W.

    The composition and implications of gamma rays observed by satellites are discussed. SAS II and COS B data from the direction of the Crab and Vela pulsars, 3C273, and the molecular cloud in the vicinity of Rho Oph are examined. It is noted that the 2-3 deg resolution of the detectors demands the consideration that cosmic ray electrons interacting with the interstellar medium could invalidate any positive definition of a particular source. Mechanisms of cosmic ray production by interstellar clouds are reviewed, and evidence is cited for a possible galactic source of some of the emissions. Observations of a 100 MeV flux coming from the direction of 2CGl95 + 04, through a relatively uncluttered region, does suggest a discrete source. Extragalactic rays possibly originate in the galactic halo. Models of equal X ray flux from all directions, with some enhancement from directions containing galaxies, seem to correspond with observations.

  10. Detection of low energy antinuclei in galactic cosmic rays The CRAC experiment

    NASA Astrophysics Data System (ADS)

    Goret, P.

    Antiproton measurements in Galactic Cosmic Rays (GCR) have been recently performed. The p-bar/p ratio measured at several GeV is found to be significantly larger than expected from secondary production in the standard leaky box model. Several scenarios have been proposed to remove the discrepancy. A critical test of these models is the p-bar/p ratio at energies below 1 GeV. The purpose of the CRAC (Cosmic Ray Antimatter Calorimeter) experiment is to measure the p-bar/p ratio in the 200-450 MeV energy range with a highly effective background rejection.

  11. On Cosmic Ray Propagation

    NASA Astrophysics Data System (ADS)

    Medvedev, Mikhail

    2014-10-01

    Cosmic ray propagation is diffusive because of pitch angle scattering by waves. We demonstrate that if the high-amplitude magnetic turbulence with δB / B ~ 1 is present on top of the mean field gradient, the diffusion becomes asymmetric. As an example, we solve this diffusion problem in one dimension analytically with a Markov chain analysis. The cosmic ray density markedly differs from the standard diffusion prediction. The equation for the continuous limit is also derived, which shows limitations of the convection-diffusion equation. We also explore how the difference of the diffusion coefficient for positively and negatively charged species may affect their distribution throughout the system (e.g., galaxy, heliosphere). The result is mostly relevant to low energy particles. The implications of the results are discussed. The results are mostly relevant to fairly low-energy cosmic rays. However, they are general enough to be applicable to any particle transport, not just cosmic rays. Supported by Grant DOE Grant DE-FG02-07ER54940 and NSF Grant AST-1209665.

  12. Galactic cosmic rays and nucleosynthesis

    SciTech Connect

    Kiener, Juergen

    2010-03-01

    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.

  13. Special Relativity in the School Laboratory: A Simple Apparatus for Cosmic-Ray Muon Detection

    ERIC Educational Resources Information Center

    Singh, P.; Hedgeland, H.

    2015-01-01

    We use apparatus based on two Geiger-Mller tubes, a simple electronic circuit and a Raspberry Pi computer to illustrate relativistic time dilation affecting cosmic-ray muons travelling through the atmosphere to the Earth's surface. The experiment we describe lends itself to both classroom demonstration to accompany the topic of special relativity

  14. Special Relativity in the School Laboratory: A Simple Apparatus for Cosmic-Ray Muon Detection

    ERIC Educational Resources Information Center

    Singh, P.; Hedgeland, H.

    2015-01-01

    We use apparatus based on two Geiger-Müller tubes, a simple electronic circuit and a Raspberry Pi computer to illustrate relativistic time dilation affecting cosmic-ray muons travelling through the atmosphere to the Earth's surface. The experiment we describe lends itself to both classroom demonstration to accompany the topic of special relativity…

  15. Detection of High Energy Cosmic Ray with the Advanced Thin Ionization Calorimeter (ATIC)

    NASA Technical Reports Server (NTRS)

    Fazely, Ali R.

    2003-01-01

    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 Gemmate (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 gamma-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.

  16. Cosmic rays and hadronic interactions

    NASA Astrophysics Data System (ADS)

    Lipari, Paolo

    2015-08-01

    The study of cosmic rays, and more in general of the "high energy universe" is at the moment a vibrant field that, thanks to the observations by several innovative detectors for relativistic charged particles, gamma-rays, and neutrinos continue to generate surprising and exciting results. The progress in the field is rapid but many fundamental problems remain open. There is an intimate relation between the study of the high energy universe and the study of the properties of hadronic interactions. High energy cosmic rays can only be studied detecting the showers they generate in the atmosphere, and for the interpretation of the data one needs an accurate modeling of the collisions between hadrons. Also the study of cosmic rays inside their sources and in the Galaxy requires a precise description of hadronic interactions. A program of experimental studies at the LHC and at lower energy, designed to address the most pressing problems, could significantly reduce the existing uncertainties and is very desirable. Such an experimental program would also have a strong intrinsic scientific interest, allowing the broadening and deepening of our understanding of Quantum Chromo Dynamics in the non-perturbative regime, the least understood sector of the Standard Model of particle physics. It should also be noted that the cosmic ray spectrum extends to particles with energy E ˜ 1020 eV, or a nucleon-nucleon c.m. energy √s ≃ 430 TeV, 30 times higher than the current LHC energy. Cosmic ray experiments therefore offer the possibility to perform studies on the properties of hadronic interactions that are impossible at accelerators.

  17. Origin of cosmic rays

    NASA Astrophysics Data System (ADS)

    Drury, Luke O.'C.

    2012-12-01

    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.

  18. Detection of High Energy Cosmic Rays with Advanced Thin Ionization Calorimeter, ATIC

    NASA Technical Reports Server (NTRS)

    Adams, J. H.; Ahn, E. J.; Ahn, H. S.; Bashindzhagyan, G.; Case, G.; Chang, J.; Christl, M.; Ellison, S.; Fazely, A. R.; Ganel, O.

    2002-01-01

    The author presents preliminary results of the first flight of the Advanced Thin Ionization Calorimeter (ATIC). ATIC is a multiple, long duration balloon flight, investigation for the study 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 pads capable of charge identification of 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'.

  19. Cosmic Rays Across the Universe

    NASA Astrophysics Data System (ADS)

    Gould Zweibel, Ellen

    2016-01-01

    Cosmic rays play an important role in the dynamics, energetics, and chemisry of gas inside and outside galaxies. It has long been recognized that gamma ray astronomy is a powerful probe of cosmic ray acceleration and propagation, and that gamma ray data, combined with other observations of cosmic rays and of the host medium and with modeling, can provide an integrated picture of cosmic rays and their environments. I will discuss the plasma physics underlying this picture, where it has been successful, and where issues remain.

  20. Special relativity in the school laboratory: a simple apparatus for cosmic-ray muon detection

    NASA Astrophysics Data System (ADS)

    Singh, P.; Hedgeland, H.

    2015-05-01

    We use apparatus based on two Geiger-Müller tubes, a simple electronic circuit and a Raspberry Pi computer to illustrate relativistic time dilation affecting cosmic-ray muons travelling through the atmosphere to the Earth’s surface. The experiment we describe lends itself to both classroom demonstration to accompany the topic of special relativity and to extended investigations for more inquisitive students.

  1. The AMY experiment to measure GHz radiation for Ultra-High Energy Cosmic Ray detection

    NASA Astrophysics Data System (ADS)

    Alvarez-Muniz, J.; Bohacova, M.; Cataldi, G.; Coluccia, M. R.; Creti, P.; De Mitri, I.; Di Giulio, C.; Engel, R.; Facal San Luis, P.; Iarlori, M.; Martello, D.; Monasor, M.; Perrone, L.; Petrera, S.; Privitera, P.; Riegel, M.; Rizi, V.; Rodriguez Fernandez, G.; Salamida, F.; Salina, G.; Settimo, M.; Smida, R.; Verzi, V.; Werner, F.; Williams, C.

    2013-02-01

    The Air Microwave Yield (AMY) project aims to measure the emission in the GHz regime from test-beam induced air-shower. The experiment is using the Beam Test Facility (BTF) of the Frascati INFN National Laboratories in Italy. The final purpose is to characterize a process to be used in a next generation of ultra-high energy cosmic rays (UHECRs) detectors. We describe the experimental apparatus and the first test performed in November 2011.

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

    NASA Technical Reports Server (NTRS)

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

    2014-01-01

    High energy cosmic rays constantly bombard the lunar regolith, producing (via nuclear evaporation) 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, and by ice deposits in permanently shadowed polar craters. Here we investigate an analogous phenomenon with high energy ((is) approximately 100 MeV) lunar albedo protons.

  3. Nineteenth International Cosmic Ray Conference. OG Sessions, Volume 3

    NASA Technical Reports Server (NTRS)

    Jones, F. C. (Compiler)

    1985-01-01

    Papers submitted for presentation at the 19th International Cosmic Ray Conference are compiled. This volume addresses cosmic ray sources and acceleration, interstellar propagation and nuclear interactions, and detection techniques and instrumentation.

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

    ERIC Educational Resources Information Center

    Friedlander, Michael

    1990-01-01

    Discussed are balloons and electroscopes, understanding cosmic rays, cosmic ray paths, isotopes and cosmic-ray travel, sources of cosmic rays, and accelerating cosmic rays. Some of the history of the discovery and study of cosmic rays is presented. (CW)

  5. Space science: Cosmic rays beyond the knees

    NASA Astrophysics Data System (ADS)

    Taylor, Andrew M.

    2016-03-01

    The development of a radio technique for detecting cosmic rays casts fresh light on the origins of some of these accelerated particles, and suggests that they might have travelled much farther than was previously thought. See Letter p.70

  6. Concept and Analysis of a Satellite for Space-Based Radio Detection of Ultra-High Energy Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Romero-Wolf, Andrew; Gorham, P.; Booth, J.; Chen, P.; Duren, R. M.; Liewer, K.; Nam, J.; Saltzberg, D.; Schoorlemmer, H.; Wissel, S.; Zairfian, P.

    2014-01-01

    We present a concept for on-orbit radio detection of ultra-high energy cosmic rays (UHECRs) that has the potential to provide collection rates of ~100 events per year for energies above 10^20 eV. The synoptic wideband orbiting radio detector (SWORD) mission's high event statistics at these energies combined with the pointing capabilities of a space-borne antenna array could enable charged particle astronomy. The detector concept is based on ANITA's successful detection UHECRs where the geosynchrotron radio signal produced by the extended air shower is reflected off the Earth's surface and detected in flight.

  7. Antiprotons in cosmic rays

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

    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.

  8. Detection of solar cosmic rays with the Mexico City neutron monitor

    NASA Astrophysics Data System (ADS)

    Vargas-Cardenas, B.; Valdes-Galicia, J. F.

    2013-05-01

    We performed a search for unreported solar cosmic ray signals on the full database of the Mexico City neutron monitor from 1989 to 2012 and present a detailed analysis of the time series corresponding to GLE 54, where we found a statistically significative increment matching the onset time of the event, thus providing evidence of acceleration of >10 GeV particles by eruptive phenomena in the solar atmosphere. We also present an estimate of the rigidity spectrum of those particles based on the registers of other American sector neutron monitors.

  9. The Origin of Cosmic Rays

    ScienceCinema

    Blasi, Pasquale [INAF/Arcetri-Italy and Fermilab, Italy

    2010-01-08

    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.

  10. JUPITER AS A GIANT COSMIC RAY DETECTOR

    SciTech Connect

    Rimmer, P. B.; Stark, C. R.; Helling, Ch.

    2014-06-01

    We explore the feasibility of using the atmosphere of Jupiter to detect ultra-high-energy cosmic rays (UHECRs). The large surface area of Jupiter allows us to probe cosmic rays of higher energies than previously accessible. Cosmic ray extensive air showers in Jupiter's atmosphere could in principle be detected by the Large Area Telescope (LAT) on the Fermi observatory. In order to be observed, these air showers would need to be oriented toward the Earth, and would need to occur sufficiently high in the atmosphere that the gamma rays can penetrate. We demonstrate that, under these assumptions, Jupiter provides an effective cosmic ray ''detector'' area of 3.3 × 10{sup 7} km{sup 2}. We predict that Fermi-LAT should be able to detect events of energy >10{sup 21} eV with fluence 10{sup –7} erg cm{sup –2} at a rate of about one per month. The observed number of air showers may provide an indirect measure of the flux of cosmic rays ≳ 10{sup 20} eV. Extensive air showers also produce a synchrotron signature that may be measurable by Atacama Large Millimeter/submillimeter Array (ALMA). Simultaneous observations of Jupiter with ALMA and Fermi-LAT could be used to provide broad constraints on the energies of the initiating cosmic rays.

  11. Cosmic ray propagation and containment

    NASA Technical Reports Server (NTRS)

    Parker, E. N.

    1976-01-01

    The cosmic rays, an active gaseous component of the disk of the galaxy, are considered along with their propagation and containment as a part of the general dynamics of the disk. The sources of cosmic rays are a matter of speculation. The disk is inflated by the cosmic ray gas pressure comparable to the magnetic pressure, but the rate of inflation is unknown. The time spent by the individual cosmic ray particles in the disk is inversely proportional to the cosmic ray production rate. It is evident from the decay of Be(1c) that the cosmic rays circulate through a volume of space perhaps ten times the thickness of the gaseous disk, suggesting a magnetic halo extending out approximately 1 kpc from either face of the disk. The cosmic rays may be responsible for the halo by inflating the magnetic fields of the disk. Extension of the fields to 1 kpc would imply a high production rate and short life of cosmic rays in the dense gaseous disk of the galaxy.

  12. Testing Galactic Cosmic Ray Models

    NASA Technical Reports Server (NTRS)

    Adams, James H., Jr.

    2009-01-01

    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.

  13. Testing Galactic Cosmic Ray Models

    NASA Technical Reports Server (NTRS)

    Adams, James H., Jr.

    2010-01-01

    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.

  14. Superbubbles and Local Cosmic Rays

    NASA Technical Reports Server (NTRS)

    Streitmatter, Robert E.; Jones, Frank C.

    2005-01-01

    We consider the possibility that distinctive features of the local cosmic ray spectra and composition are influenced by the Solar system being embedded within the cavity of an ancient superbubble. Shifts in the measured cosmic ray composition between 10(exp 11) and 10(exp 20) eV as well as the "knee" and "second knee" may be understood in this picture.

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

    NASA Astrophysics Data System (ADS)

    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

    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 2σ 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.

  16. Solar Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Miroshnichenko, Leonty I.

    2001-05-01

    The book summarizes the results of solar cosmic-ray (SCR) investigations since 1942. The present monograph, unlike the reviews published earlier, treats the problem in self-contained form, in all its associations - from fundamental astrophysical aspects to geophysical and astronautical applications. It includes a large amount of new data, accumulated during the last two or three decades of space research. As a result of the `information burst' in space physics, there are a lot of new interesting theoretical concepts, models, and ideas that deserve attention. The author gives an extensive bibliography which covers incompartially the main achievements and failures in this field. The book will be helpful for a wide audience of space physicists and it will be relevant to graduate and postgraduate courses.

  17. COSMIC-RAY TRANSPORT AND ANISOTROPIES

    SciTech Connect

    Biermann, Peter L.; Becker Tjus, Julia; Mandelartz, Matthias; Seo, Eun-Suk

    2013-05-10

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

  18. Detection of transient ELF emission caused by the extremely intense cosmic gamma-ray flare of 27 December 2004

    NASA Astrophysics Data System (ADS)

    Tanaka, Y. T.; Hayakawa, M.; Hobara, Y.; Nickolaenko, A. P.; Yamashita, K.; Sato, M.; Takahashi, Y.; Terasawa, T.; Takahashi, T.

    2011-04-01

    We report on the first clear detection of transient Extremely-Low-Frequency (ELF) signal caused by an extremely intense cosmic gamma-ray flare. On 2004 December 27, the brightest gamma-ray flare ever recorded was observed by numerous satellites. A transient ELF emission observed at Moshiri and Onagawa in Japan exactly coincided with the peak time of the flare, and its wide pulse width of ˜40 ms disfavors the possibility of lightning origin. Furthermore, the two horizontal components of ELF magnetic field data recorded at Esrange in Sweden showed clear transient Schumann resonance waveforms. The source direction determined by the Lissajous method roughly corresponds to the subflare point. The chance probability that a sprite occurs within 30 ms of the peak flare time is ˜0.025%, which again clearly excludes the sprite origin. Thus, a bright cosmic gamma-ray flare is a new source of transient ELF radio signals observed on the Earth, although the emission mechanism needs to be clarified in future.

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

    NASA Astrophysics Data System (ADS)

    Khanin, Alexander; Mortlock, Daniel J.

    2014-10-01

    Cosmic rays are protons and atomic nuclei that flow into our Solar system and reach the Earth with energies of up to 1021 eV. The sources of ultrahigh energy cosmic rays (UHECRs) with E ? 1019 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 analysing the self-clustering of points on the sphere, which we apply to the UHECR arrival directions. The analysis is based on a multistep 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, 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 data set of this size. Data sets of several hundred UHECRs would be sufficient to detect clustering in the AGN model. Samples of this magnitude are expected to be produced by future experiments, such as the Japanese Experiment Module Extreme Universe Space Observatory.

  20. Searches for anisotropies in the arrival directions of the highest energy cosmic rays detected by the Pierre Auger Observatory

    DOE PAGESBeta

    Aab, Alexander

    2015-05-01

    We analyze the distribution of arrival directions of ultra-high-energy cosmic rays recorded at the Pierre Auger Observatory in 10 years of operation. The data set, about three times larger than that used in earlier studies, includes arrival directions with zenith angles up to 80°, thus covering from -90° to +45° in declination. After updating the fraction of events correlating with the active galactic nuclei (AGNs) in the Véron-Cetty and Véron catalog, we subject the arrival directions of the data with energies in excess of 40 EeV to different tests for anisotropy. We search for localized excess fluxes, self-clustering of event directions at angular scales up to 30°, and different threshold energies between 40 and 80 EeV. We then look for correlations of cosmic rays with celestial structures both in the Galaxy (the Galactic Center and Galactic Plane) and in the local universe (the Super-Galactic Plane). We also examine their correlation with different populations of nearby extragalactic objects: galaxies in the 2MRS catalog, AGNs detected by Swift-BAT, radio galaxies with jets, and the Centaurus A (Cen A) galaxy. None of the tests show statistically significant evidence of anisotropy. As a result, the strongest departures from isotropy (post-trial probabilitymore » $$\\sim 1.4$$%) are obtained for cosmic rays with $$E\\gt 58$$ EeV in rather large windows around Swift AGNs closer than 130 Mpc and brighter than 1044 erg s-1 (18° radius), and around the direction of Cen A (15° radius).« less

  1. Searches for anisotropies in the arrival directions of the highest energy cosmic rays detected by the Pierre Auger Observatory

    SciTech Connect

    Aab, Alexander

    2015-05-01

    We analyze the distribution of arrival directions of ultra-high-energy cosmic rays recorded at the Pierre Auger Observatory in 10 years of operation. The data set, about three times larger than that used in earlier studies, includes arrival directions with zenith angles up to 80°, thus covering from -90° to +45° in declination. After updating the fraction of events correlating with the active galactic nuclei (AGNs) in the Véron-Cetty and Véron catalog, we subject the arrival directions of the data with energies in excess of 40 EeV to different tests for anisotropy. We search for localized excess fluxes, self-clustering of event directions at angular scales up to 30°, and different threshold energies between 40 and 80 EeV. We then look for correlations of cosmic rays with celestial structures both in the Galaxy (the Galactic Center and Galactic Plane) and in the local universe (the Super-Galactic Plane). We also examine their correlation with different populations of nearby extragalactic objects: galaxies in the 2MRS catalog, AGNs detected by Swift-BAT, radio galaxies with jets, and the Centaurus A (Cen A) galaxy. None of the tests show statistically significant evidence of anisotropy. As a result, the strongest departures from isotropy (post-trial probability $\\sim 1.4$%) are obtained for cosmic rays with $E\\gt 58$ EeV in rather large windows around Swift AGNs closer than 130 Mpc and brighter than 1044 erg s-1 (18° radius), and around the direction of Cen A (15° radius).

  2. Searches for Anisotropies in the Arrival Directions of the Highest Energy Cosmic Rays Detected by the Pierre Auger Observatory

    NASA Astrophysics Data System (ADS)

    Aab, A.; Abreu, P.; Aglietta, M.; Ahn, E. J.; Samarai, I. Al; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Aramo, C.; Aranda, V. M.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Awal, N.; Badescu, A. M.; Barber, K. B.; Bäuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertaina, M. E.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blaess, S. G.; Blanco, M.; Bleve, C.; Blümer, H.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Bridgeman, A.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Buitink, S.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Candusso, M.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Chavez, A. G.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Coleman, A.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cooper, M. J.; Cordier, A.; Coutu, S.; Covault, C. E.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; de Jong, S. J.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Di Matteo, A.; Diaz, J. C.; Díaz Castro, M. L.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dorofeev, A.; Dorosti Hasankiadeh, Q.; Dova, M. T.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fernandes, M.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipčič, A.; Fox, B. D.; Fratu, O.; Freire, M. M.; Fröhlich, U.; Fuchs, B.; Fujii, T.; Gaior, R.; García, B.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gate, F.; Gemmeke, H.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Glaser, C.; Glass, H.; Gómez Berisso, M.; Gómez Vitale, P. F.; Gonçalves, P.; Gonzalez, J. G.; González, N.; Gookin, B.; Gordon, J.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guarino, F.; Guedes, G. P.; Hampel, M. R.; Hansen, P.; Harari, D.; Harrison, T. A.; Hartmann, S.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huber, D.; Huege, T.; Insolia, A.; Isar, P. G.; Jandt, I.; Jansen, S.; Jarne, C.; Josebachuili, M.; Kääpä, A.; Kambeitz, O.; Kampert, K. H.; Kasper, P.; Katkov, I.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kunka, N.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Malacari, M.; Maldera, S.; Mallamaci, M.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Mariş, I. C.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martínez Bravo, O.; Martraire, D.; Masías Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Meissner, R.; Melissas, M.; Melo, D.; Menshikov, A.; Messina, S.; Meyhandan, R.; Mićanović, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morello, C.; Mostafá, M.; Moura, C. A.; Muller, M. A.; Müller, G.; Müller, S.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nguyen, P. H.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nožka, L.; Ochilo, L.; Oikonomou, F.; Olinto, A.; Oliveira, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Papenbreer, P.; Parente, G.; Parra, A.; Paul, T.; Pech, M.; Pȩkala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Petermann, E.; Peters, C.; Petrera, S.; Petrov, Y.; Phuntsok, J.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porcelli, A.; Porowski, C.; Prado, R. R.; Privitera, P.; Prouza, M.; Purrello, V.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rizi, V.; Rodrigues de Carvalho, W.; Rodriguez Fernandez, G.; Rodriguez Rojo, J.; Rodríguez-Frías, M. D.; Rogozin, D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Roulet, E.; Rovero, A. C.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Saleh, A.; Salesa Greus, F.; Salina, G.; Sánchez, F.; Sanchez-Lucas, P.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarmento, R.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, D.; Scholten, O.; Schoorlemmer, H.; Schovánek, P.; Schröder, F. G.; Schulz, A.; Schulz, J.; Schumacher, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Sima, O.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Squartini, R.; Srivastava, Y. N.; Stanič, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Taborda, O. A.; Tapia, A.; Tepe, A.; Theodoro, V. M.; Timmermans, C.; Todero Peixoto, C. J.; Toma, G.; Tomankova, L.; Tomé, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Travnicek, P.; Trovato, E.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van Bodegom, P.; van den Berg, A. M.; van Velzen, S.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Varner, G.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Vicha, J.; Videla, M.; Villase ñor, L.; Vlcek, B.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Widom, A.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Williams, C.; Winchen, T.; Wittkowski, D.; Wundheiler, B.; Wykes, S.; Yamamoto, T.; Yapici, T.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.; Zuccarello, F.; Pierre Auger Collaboration

    2015-05-01

    We analyze the distribution of arrival directions of ultra-high-energy cosmic rays recorded at the Pierre Auger Observatory in 10 years of operation. The data set, about three times larger than that used in earlier studies, includes arrival directions with zenith angles up to 80°, thus covering from -90{}^\\circ to +45{}^\\circ in declination. After updating the fraction of events correlating with the active galactic nuclei (AGNs) in the Véron-Cetty and Véron catalog, we subject the arrival directions of the data with energies in excess of 40 EeV to different tests for anisotropy. We search for localized excess fluxes, self-clustering of event directions at angular scales up to 30°, and different threshold energies between 40 and 80 EeV. We then look for correlations of cosmic rays with celestial structures both in the Galaxy (the Galactic Center and Galactic Plane) and in the local universe (the Super-Galactic Plane). We also examine their correlation with different populations of nearby extragalactic objects: galaxies in the 2MRS catalog, AGNs detected by Swift-BAT, radio galaxies with jets, and the Centaurus A (Cen A) galaxy. None of the tests show statistically significant evidence of anisotropy. The strongest departures from isotropy (post-trial probability ˜ 1.4%) are obtained for cosmic rays with E\\gt 58 EeV in rather large windows around Swift AGNs closer than 130 Mpc and brighter than 1044 erg s-1 (18° radius), and around the direction of Cen A (15° radius).

  3. Searches for anisotropies in the arrival directions of the highest energy cosmic rays detected by the Pierre Auger Observatory

    SciTech Connect

    Aab, Alexander

    2015-05-01

    We analyze the distribution of arrival directions of ultra-high-energy cosmic rays recorded at the Pierre Auger Observatory in 10 years of operation. The data set, about three times larger than that used in earlier studies, includes arrival directions with zenith angles up to 80, thus covering from -90 to +45 in declination. After updating the fraction of events correlating with the active galactic nuclei (AGNs) in the Vron-Cetty and Vron catalog, we subject the arrival directions of the data with energies in excess of 40 EeV to different tests for anisotropy. We search for localized excess fluxes, self-clustering of event directions at angular scales up to 30, and different threshold energies between 40 and 80 EeV. We then look for correlations of cosmic rays with celestial structures both in the Galaxy (the Galactic Center and Galactic Plane) and in the local universe (the Super-Galactic Plane). We also examine their correlation with different populations of nearby extragalactic objects: galaxies in the 2MRS catalog, AGNs detected by Swift-BAT, radio galaxies with jets, and the Centaurus A (Cen A) galaxy. None of the tests show statistically significant evidence of anisotropy. As a result, the strongest departures from isotropy (post-trial probability $\\sim 1.4$%) are obtained for cosmic rays with $E\\gt 58$ EeV in rather large windows around Swift AGNs closer than 130 Mpc and brighter than 1044 erg s-1 (18 radius), and around the direction of Cen A (15 radius).

  4. Cosmic ray studies at CERN

    SciTech Connect

    Fernandez T, Arturo

    2006-09-25

    The use of the sophisticated and large underground detectors at CERN for cosmic ray studies has been considered by several groups, e.g. UA1, LEP and LHC detectors. They offer the opportunity to provide large sensitivity area with magnetic analysis which allow a precise determination of the direction of cosmic ray muons as well as their momentum up to the order of some TeV. The aim of this article is to review the observation of high energy cosmic ray muons using precise spectrometers at CERN, mainly LEP detectors as well as the possibility of improve those measurements with LHC apparatus, giving special emphasis to the ACORDE-ALICE cosmic ray physics program.

  5. Cosmic rays, clouds, and climate.

    PubMed

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

    2002-11-29

    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, who accept them as reliable, suggest that the correlation may be caused by other physical phenomena with decadal periods or by a response to volcanic activity or El Niño. Nevertheless, the observation has raised the intriguing possibility that a cosmic ray-cloud interaction may help explain how a relatively small change in solar output can produce much larger changes in Earth's climate. Physical mechanisms have been proposed to explain how cosmic rays could affect clouds, but they need to be investigated further if the observation is to become more than just another correlation among geophysical variables. PMID:12459578

  6. Protostars: Forges of cosmic rays?

    NASA Astrophysics Data System (ADS)

    Padovani, M.; Marcowith, A.; Hennebelle, P.; Ferrière, K.

    2016-04-01

    Context. Galactic cosmic rays are particles presumably accelerated in supernova remnant shocks that propagate in the interstellar medium up to the densest parts of molecular clouds, losing energy and their ionisation efficiency because of the presence of magnetic fields and collisions with molecular hydrogen. Recent observations hint at high levels of ionisation and at the presence of synchrotron emission in protostellar systems, which leads to an apparent contradiction. Aims: We want to explain the origin of these cosmic rays accelerated within young protostars as suggested by observations. Methods: Our modelling consists of a set of conditions that has to be satisfied in order to have an efficient cosmic-ray acceleration through diffusive shock acceleration. We analyse three main acceleration sites (shocks in accretion flows, along the jets, and on protostellar surfaces), then we follow the propagation of these particles through the protostellar system up to the hot spot region. Results: We find that jet shocks can be strong accelerators of cosmic-ray protons, which can be boosted up to relativistic energies. Other promising acceleration sites are protostellar surfaces, where shocks caused by impacting material during the collapse phase are strong enough to accelerate cosmic-ray protons. In contrast, accretion flow shocks are too weak to efficiently accelerate cosmic rays. Though cosmic-ray electrons are weakly accelerated, they can gain a strong boost to relativistic energies through re-acceleration in successive shocks. Conclusions: We suggest a mechanism able to accelerate both cosmic-ray protons and electrons through the diffusive shock acceleration mechanism, which can be used to explain the high ionisation rate and the synchrotron emission observed towards protostellar sources. The existence of an internal source of energetic particles can have a strong and unforeseen impact on the ionisation of the protostellar disc, on the star and planet formation processes, and on the formation of pre-biotic molecules.

  7. Search for Anisotropies in Cosmic-ray Positrons Detected By the PAMELA Experiment

    NASA Astrophysics Data System (ADS)

    Adriani, O.; Barbarino, G. C.; Bazilevskaya, G. A.; Bellotti, R.; Boezio, M.; Bogomolov, E. A.; Bongi, M.; Bonvicini, V.; Bottai, S.; Bruno, A.; Cafagna, F.; Campana, D.; Carlson, P.; Casolino, M.; Castellini, G.; De Donato, C.; De Santis, C.; De Simone, N.; Di Felice, V.; Formato, V.; Galper, A. M.; Giaccari, U.; Karelin, A. V.; Koldashov, S. V.; Koldobskiy, S.; Krutkov, S. Y.; Kvashnin, A. N.; Leonov, A.; Malakhov, V.; Marcelli, L.; Martucci, M.; Mayorov, A. G.; Menn, W.; Mergé, M.; Mikhailov, V. V.; Mocchiutti, E.; Monaco, A.; Mori, N.; Munini, R.; Osteria, G.; Palma, F.; Panico, B.; Papini, P.; Pearce, M.; Picozza, P.; Ricci, M.; Ricciarini, S. B.; Sarkar, R.; Scotti, V.; Simon, M.; Sparvoli, R.; Spillantini, P.; Stozhkov, Y. I.; Vacchi, A.; Vannuccini, E.; Vasilyev, G. I.; Voronov, S. A.; Yurkin, Y. T.; Zampa, G.; Zampa, N.

    2015-09-01

    The Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) detector was launched on board the Russian Resurs-DK1 satellite on 2006 June 15. The data collected during the first four years have been used to search for large-scale anisotropies in the arrival directions of cosmic ray positrons. The PAMELA experiment allows for a full sky investigation, with sensitivity to global anisotropies in any angular window of the celestial sphere. Data samples of positrons in the rigidity range of 10 GV ≤slant R ≤slant 200 GV were analyzed. This article discusses the method and the results of the search for possible local sources through the analysis of anisotropy in positron data compared to the proton background. The resulting distributions of arrival directions are found to be isotropic. Starting from the angular power spectrum, a dipole anisotropy upper limit of δ = 0.076 at the 95% confidence level is determined. An additional search is carried out around the Sun. No evidence of an excess correlated with that direction was found.

  8. Galactic Cosmic Rays: From Earth to Sources

    NASA Technical Reports Server (NTRS)

    Brandt, Theresa J.

    2012-01-01

    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.

  9. Cosmic-Ray Observations with HAWC30

    NASA Astrophysics Data System (ADS)

    Fiorino, Daniel

    2013-04-01

    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.

  10. Detection of high energy cosmic rays with the resonant gravitational wave detectors NAUTILUS and EXPLORER and comparison with the direct measurements with an aluminum superconductive bar

    NASA Astrophysics Data System (ADS)

    Ronga, F.; ROG Collaboration; RAP Collaboration

    2009-05-01

    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 largest event detected up to now has an energy in the first longitudinal mode of ˜ 670 K corresponding to ˜ 360 TeV in the bar.

  11. Perspective of monochromatic gamma-ray line detection with the High Energy cosmic-Radiation Detection (HERD) facility onboard China's space station

    NASA Astrophysics Data System (ADS)

    Huang, Xiaoyuan; Lamperstorfer, Anna S.; Tsai, Yue-Lin Sming; Xu, Ming; Yuan, Qiang; Chang, Jin; Dong, Yong-Wei; Hu, Bing-Liang; Lü, Jun-Guang; Wang, Le; Wu, Bo-Bing; Zhang, Shuang-Nan

    2016-05-01

    HERD is the High Energy cosmic-Radiation Detection instrument proposed to operate onboard China's space station in the 2020s. It is designed to detect energetic cosmic ray nuclei, leptons and photons with a high energy resolution (∼1% for electrons and photons and 20% for nuclei) and a large geometry factor (>3 m2 sr for electrons and diffuse photons and > [2]m2 sr for nuclei). In this work we discuss the capability of HERD to detect monochromatic γ-ray lines, based on simulations of the detector performance. It is shown that HERD will be one of the most sensitive instruments for monochromatic γ-ray searches at energies between ∼ 10 to a few hundred GeV. Above hundreds of GeV, Cherenkov telescopes will be more sensitive due to their large effective area. As a specific example, we show that a good portion of the parameter space of a supersymmetric dark matter model can be probed with HERD.

  12. Investigation of primary cosmic rays at the Moon's surface

    SciTech Connect

    Kalmykov, N. N. Konstantinov, A. A.; Muhamedshin, R. A.; Podorozhniy, D. M.; Sveshnikova, L. G.; Turundaevskiy, A. N.; Tkachev, L. G.; Chubenko, A. P.; Vasilyev, O. A.

    2013-01-15

    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).

  13. Gamma ray line production from cosmic ray spallation reactions

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    The gamma ray line intensities due to cosmic ray spallation reactions in clouds, the galactic disk and accreting binary pulsars are calculated. With the most favorable plausible assumptions, only a few lines may be detectable to the level of 0.0000001 per sq. cm per sec. The intensities are compared with those generated in nuclear excitation reactions.

  14. Monopole annihilation and highest energy cosmic rays

    SciTech Connect

    Bhattacharjee, P. Indian Institute of Astrophysics, Sarjapur Road, Koramangala, Bangalore 560 034 ); Sigl, G. NASA/Fermilab Astrophysics Center, Fermi National Accelerator Laboratory, Batavia, Illinois 60510-0500 )

    1995-04-15

    Cosmic rays with energies exceeding 10[sup 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 the literature. In this paper we study the possibility of producing the highest energy cosmic rays through a process that involves the 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.

  15. Catching Cosmic Rays with a DSLR

    ERIC Educational Resources Information Center

    Sibbernsen, Kendra

    2010-01-01

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

  16. Catching Cosmic Rays with a DSLR

    ERIC Educational Resources Information Center

    Sibbernsen, Kendra

    2010-01-01

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

  17. Cosmic Rays and Global Warming

    SciTech Connect

    Sloan, T.; Wolfendale, A. W.

    2008-01-24

    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.

  18. Nonlinear Cosmic Ray Diffusion Theories

    NASA Astrophysics Data System (ADS)

    Shalchi, Andreas

    Within cosmic ray transport theory, we investigate the interaction between energetic charged particles like electrons, protons, or heavy ions and astrophysical plasmas such as the solar wind or the interstellar medium. These particles interact with a background magnetic field B 0 and with turbulent electric and magnetic fields ýE and ýB, and they therefore experience scattering parallel and perpendicular to B 0. In this introductory chapter, general properties of cosmic rays are discussed, as well as the unperturbed motion of the particles. Furthermore, the physics of parallel and perpendicular scattering is investigated. At the end of this chapter, we consider observed mean free paths of cosmic rays in the heliosphere and in the interstel- lar medium. One aim of this book is to demonstrate that a nonlinear description of particle transport is necessary to reproduce these measurements.

  19. Efficacy of Cosmic Ray Shields

    NASA Astrophysics Data System (ADS)

    Rhodes, Nicholas

    2015-10-01

    This research involved testing various types of shielding with a self-constructed Berkeley style cosmic ray detector, in order to evaluate the materials of each type of shielding's effectiveness at blocking cosmic rays and the cost- and size-efficiency of the shields as well. The detector was constructed, then tested for functionality and reliability. Following confirmation, the detector was then used at three different locations to observe it altitude or atmospheric conditions had any effect on the effectiveness of certain shields. Multiple types of shielding were tested with the detector, including combinations of several shields, primarily aluminum, high-iron steel, polyethylene plastic, water, lead, and a lead-alternative radiation shield utilized in radiology. These tests regarding both the base effectiveness and the overall efficiency of shields is designed to support future space exploratory missions where the risk of exposure to possibly lethal amounts of cosmic rays for crew and the damage caused to unshielded electronics are of serious concern.

  20. Asymmetric diffusion of cosmic rays

    NASA Astrophysics Data System (ADS)

    Medvedev, Mikhail V.; Medvedev, Viktor V.

    2015-09-01

    Cosmic ray propagation is diffusive because of pitch angle scattering by waves. We demonstrate that if the high-amplitude magnetohydrodynamic turbulence with B ˜/˜1 is present on top of the mean field gradient, the diffusion becomes asymmetric. As an example, we consider the vertical transport of cosmic rays in our Galaxy propagating away from a point-like source. We solve this diffusion problem analytically using a one-dimensional Markov chain analysis. We obtained that the cosmic ray density markedly differs from the standard diffusion prediction and has a sizable effect on their distribution throughout the galaxy. The equation for the continuous limit is also derived, which shows limitations of the convection-diffusion equation.

  1. Compact cosmic ray detector for unattended atmospheric ionization monitoring

    SciTech Connect

    Aplin, K. L.; Harrison, R. G.

    2010-12-15

    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.

  2. Aligned interactions in cosmic rays

    SciTech Connect

    Kempa, J.

    2015-12-15

    The first clean Centauro was found in cosmic rays years many ago at Mt Chacaltaya experiment. Since that time, many people have tried to find this type of interaction, both in cosmic rays and at accelerators. But no one has found a clean cases of this type of interaction.It happened finally in the last exposure of emulsion at Mt Chacaltaya where the second clean Centauro has been found. The experimental data for both the Centauros and STRANA will be presented and discussed in this paper. We also present our comments to the intriguing question of the existence of a type of nuclear interactions at high energy with alignment.

  3. Cosmic rays at fluid discontinuities

    NASA Technical Reports Server (NTRS)

    Jokipii, J. R.; Kota, J.; Morfill, G.

    1989-01-01

    Cosmic-ray transport near discontinuities in the background fluid velocity is considered. Matching conditions for the cosmic-ray distribution are derived for both shear and compressive (shock) discontinuities, keeping terms to second order in the ratio of fluid speed to energetic-particle speed. Acceleration is found at shear discontinuities, which is not present in the first-order theory, and a modification of the matching condition at shocks. If there is no particle source concentrated at a shock, the new condition reduces to that obtained from first-order theory. Monte Carlo simulations show good agreement with the theory.

  4. Aligned interactions in cosmic rays

    NASA Astrophysics Data System (ADS)

    Kempa, J.

    2015-12-01

    The first clean Centauro was found in cosmic rays years many ago at Mt Chacaltaya experiment. Since that time, many people have tried to find this type of interaction, both in cosmic rays and at accelerators. But no one has found a clean cases of this type of interaction.It happened finally in the last exposure of emulsion at Mt Chacaltaya where the second clean Centauro has been found. The experimental data for both the Centauros and STRANA will be presented and discussed in this paper. We also present our comments to the intriguing question of the existence of a type of nuclear interactions at high energy with alignment.

  5. Fun Times with Cosmic Rays

    NASA Technical Reports Server (NTRS)

    Wanjek, Christopher

    2003-01-01

    Who would have thought cosmic rays could be so hip? Although discovered 90 years ago on death-defying manned balloon flights hip even by twenty-first-century extremesport standards cosmic rays quickly lost popularity as way-cool telescopes were finding way-too-cool phenomena across the electromagnetic spectrum. Yet cosmic rays are back in vogue, boasting their own set of superlatives. Scientists are tracking them down with new resolve from the Arctic to Antarctica and even on the high western plains of Argentina. Theorists, too, now see cosmic rays as harbingers of funky physics. Cosmic rays are atomic and subatomic particles - the fastest moving bits of matter in the universe and the only sample of matter we have from outside the solar system (with the exception of interstellar dust grains). Lower-energy cosmic rays come from the Sun. Mid-energy particles come from stellar explosions - either spewed directly from the star like shrapnel, or perhaps accelerated to nearly the speed of light by shock waves. The highest-energy cosmic rays, whose unequivocal existence remains one of astronomy's greatest mysteries, clock in at a staggering 10(exp 19) to 10(exp 22) electron volts. This is the energy carried in a baseball pitch; seeing as how there are as many atomic particles in a baseball as there are baseballs in the Moon, that s one powerful toss. No simple stellar explosion could produce them. At a recent conference in Albuquerque, scientists presented the first observational evidence of a possible origin for the highest-energy variety. A team led by Elihu Boldt at NASA s Goddard Space Flight Center found that five of these very rare cosmic rays (there are only a few dozen confirmed events) come from the direction of four 'retired' quasar host galaxies just above the arm of the Big Dipper, all visible with backyard telescopes: NGC 3610, NGC 3613, NGC 4589, and NGC 5322. These galaxies are billions of years past their glory days as the brightest beacons in the universe. Yet they still harbor central, supermassive black holes, which could generate energetic particles if they are spinning.

  6. Cosmic Ray Anisotropy with KASCADE

    NASA Astrophysics Data System (ADS)

    Maier, G.; Antoni, T.; Apel, W. D.; Badea, F.; Bekk, K.; Bercuci, A.; Blmer, H.; Bozdog, H.; Brancus, I. M.; Bttner, C.; Chilingarian, A.; Daumiller, K.; Doll, P.; Engel, R.; Engler, J.; Feler, F.; Gils, H. J.; Glasstetter, R.; Haungs, A.; Heck, D.; Hrandel, J. R.; Iwan, A.; Kampert, K. H.; Klages, H. O.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mller, M.; Obenland, R.; Oehlschlger, J.; Ostapchenko, S.; Petcu, M.; Rebel, H.; Risse, M.; Schatz, G.; Schieler, H.; Scholz, J.; Thouw, T.; Ulrich, H.; van Buren, J.; Vardanyan, A.; Weindl, A.; Wochele, J.; Zabierowski, J.

    2003-07-01

    The anisotropy of cosmic rays with energies in the region of the knee in the energy spectrum is investigated in three different persp ectives based on the arrival directions of about 150 Mio. extensive air showers measured by KASCADE. The different analyses are a harmonic analysis of the right ascension distribution and a point source search of showers above 0.5 PeV as well as an auto correlation analysis of showers above 100 PeV. All three analyses agree inside the statistical limits with an isotropic distribution of the arrival directions of cosmic rays.

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  8. The microphysics and macrophysics of cosmic rays

    SciTech Connect

    Zweibel, Ellen G.

    2013-05-15

    This review paper commemorates a century of cosmic ray research, with emphasis on the plasma physics aspects. Cosmic rays comprise only ∼10{sup −9} of interstellar particles by number, but collectively their energy density is about equal to that of the thermal particles. They are confined by the Galactic magnetic field and well scattered by small scale magnetic fluctuations, which couple them to the local rest frame of the thermal fluid. Scattering isotropizes the cosmic rays and allows them to exchange momentum and energy with the background medium. I will review a theory for how the fluctuations which scatter the cosmic rays can be generated by the cosmic rays themselves through a microinstability excited by their streaming. A quasilinear treatment of the cosmic ray–wave interaction then leads to a fluid model of cosmic rays with both advection and diffusion by the background medium and momentum and energy deposition by the cosmic rays. This fluid model admits cosmic ray modified shocks, large scale cosmic ray driven instabilities, cosmic ray heating of the thermal gas, and cosmic ray driven galactic winds. If the fluctuations were extrinsic turbulence driven by some other mechanism, the cosmic ray background coupling would be entirely different. Which picture holds depends largely on the nature of turbulence in the background medium.

  9. Evaluation of Galactic Cosmic Ray Models

    NASA Technical Reports Server (NTRS)

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

    2009-01-01

    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.

  10. Final Report for NA-22/DTRA Cosmic Ray Project

    SciTech Connect

    Wurtz, Ron E.; Chapline, George F.; Glenn, Andrew M.; Nakae, Les F.; Pawelczak, Iwona A.; Sheets, Steven A.

    2015-07-21

    The primary objective of this project was to better understand the time-correlations between the muons and neutrons produced as a result of high energy primary cosmic ray particles hitting the atmosphere, and investigate whether these time correlations might be useful in connection with the detection of special nuclear materials. During the course of this project we did observe weak correlations between secondary cosmic ray muons and cosmic ray induced fast neutrons. We also observed strong correlations between tertiary neutrons produced in a Pb pile by secondary cosmic rays and minimum ionizing particles produced in association with the tertiary neutrons.

  11. The Cosmic Ray Electron Excess

    NASA Technical Reports Server (NTRS)

    Chang, J.; Adams, J. H.; Ahn, H. S.; Bashindzhagyan, G. L.; Christl, M.; Ganel, O.; Guzik, T. G.; Isbert, J.; Kim, K. C.; Kuznetsov, E. N.; 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

    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.

  12. Cosmic rays and hadronic interactions

    SciTech Connect

    Lipari, Paolo

    2013-03-25

    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.

  13. X-ray Observations of Cosmic Ray Acceleration

    NASA Technical Reports Server (NTRS)

    Petre, Robert

    2012-01-01

    Since the discovery of cosmic rays, detection of their sources has remained elusive. A major breakthrough has come through the identification of synchrotron X-rays from the shocks of supernova remnants through imaging and spectroscopic observations by the most recent generation of X-ray observatories. This radiation is most likely produced by electrons accelerated to relativistic energy, and thus has offered the first, albeit indirect, observational evidence that diffusive shock acceleration in supernova remnants produces cosmic rays to TeV energies, possibly as high as the "knee" in the cosmic ray spectrum. X-ray observations have provided information about the maximum energy to which these shOCks accelerate electrons, as well as indirect evidence of proton acceleration. Shock morphologies measured in X-rays have indicated that a substantial fraction of the shock energy can be diverted into particle acceleration. This presentation will summarize what we have learned about cosmic ray acceleration from X-ray observations of supernova remnants over the past two decades.

  14. Detectors for Cosmic Rays on Ground and in Space

    SciTech Connect

    Tajima, Hiroyasu; /SLAC

    2007-09-10

    The origin of the cosmic rays has been a great mystery since they were discovered by Victor Hess in 1912. AGASA's observation of ultra-high-energy cosmic-rays (UHECR) possibly beyond the GZK (Greisen, Zatsepin and Kuzmin) cutoff stimulated the field in great deal. In addition, Kamiokande's detection of neutrinos from SN1987A and the H.E.S.S.'s detection of TeV gamma-rays from supernova remnants demonstrated the viability of neutrino and TeV gamma-ray astronomy for cosmic-ray research. A new generation of currently-operating or soon-to-be-operating detectors for charged particles, gamma-rays and neutrinos from cosmos will get us even closer to understanding the nature and origin of cosmic rays. Detectors for UHECRs, gamma rays and neutrinos are of particular importance in order to study the origins of cosmic rays since these particles are free from the deflection due to magnetic fields. Detectors for antiparticles and gamma rays would be useful to detect cosmic rays originated from the decay of the dark matter in the Universe. I will review these cosmic-ray detectors with particular attention on the differences of ground-based, balloon-borne and satellite-borne detectors.

  15. Research in cosmic and gamma ray astrophysics

    NASA Technical Reports Server (NTRS)

    Stone, Edward C.; Mewaldt, Richard A.; Prince, Thomas A.

    1992-01-01

    Discussed here is research in cosmic ray and gamma ray astrophysics at the Space Radiation Laboratory (SRL) of the California Institute of Technology. The primary activities discussed involve the development of new instrumentation and techniques for future space flight. In many cases these instrumentation developments were tested in balloon flight instruments designed to conduct new investigations in cosmic ray and gamma ray astrophysics. The results of these investigations are briefly summarized. Specific topics include a quantitative investigation of the solar modulation of cosmic ray protons and helium nuclei, a study of cosmic ray positron and electron spectra in interplanetary and interstellar space, the solar modulation of cosmic rays, an investigation of techniques for the measurement and interpretation of cosmic ray isotopic abundances, and a balloon measurement of the isotopic composition of galactic cosmic ray boron, carbon, and nitrogen.

  16. Detection of OH+ in Translucent Interstellar Clouds: New Electronic Transitions and Probing the Primary Cosmic Ray Ionization Rate

    NASA Astrophysics Data System (ADS)

    Zhao, D.; Galazutdinov, G. A.; Linnartz, H.; Krełowski, J.

    2015-06-01

    We present the detection of rotationally resolved electronic transitions in the OH+ A3Π-X3Σ- (0, 0) and (1, 0) bands toward CD-32 4348, HD 63804, HD 78344, and HD 80077. These four translucent clouds have been studied in a recent Very Large Telescope/Ultraviolet and Visual Echelle Spectrograph observational run. In total, seven absorption features of OH+ are detected, and six of them are identified here for the first time, providing a precise tool to trace OH+ in translucent interstellar clouds. An improved set of line positions and oscillator strengths is compiled to support our data interpretation. A dedicated analysis of the observed features in individual targets yields an accurate determination of OH+ column densities. The results are applied to estimate the primary cosmic ray ionization rate in the investigated translucent clouds, which yields a typical value of ˜1.0 × 10-16 s-1. In addition, following this work, two of the new interstellar features recently reported by Bhatt & Cami, at ˜3572.65 and 3346.96 Å, can be identified as OH+ absorption lines now. Based on observations collected at the European Organisation for Astronomical Research in the southern hemisphere, Chile, under program 092.C-0019(A).

  17. Nineteenth International Cosmic Ray Conference. SH Sessions, Volume 5

    NASA Technical Reports Server (NTRS)

    Jones, F. C. (Compiler)

    1985-01-01

    Papers submitted for presentation at the 19th International Cosmic Ray Conference are compiled. This volume contains papers addressing cosmic ray gradients in the heliosphere; siderial, diurnal, and long term modulations; geomagnetic and atmospheric effects; cosmogenic nuclides; solar neutrinos; and detection techniques.

  18. Cosmic X ray physics

    NASA Astrophysics Data System (ADS)

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

    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.

  19. Cosmic x ray physics

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

    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.

  20. Cosmic rays from binary neutron stars

    NASA Astrophysics Data System (ADS)

    Kundt, W.

    1983-02-01

    The acceleration mechanism of cosmic rays is discussed. Parker's (1965, 1979) suggestion that buoyant reordering of magnetic flux tubes is the dominant transport mechanism of cosmic rays out of the galactic disk is reinforced. Arguments that the cosmic ray sources are located inside the molecular cloud layer are presented, and the shock accretion model as the primary mechanism of cosmic ray acceleration is argued against. A model of cosmic ray acceleration is presented in which the ionic component of the rays is injected by young binary neutron stars whose rotating magnetospheres act like grindstones in the wind of their companion. The model appears versatile enough to be consistent with the observed abundance anomalies. While pulsars are probably not the dominant source of cosmic ray nuclei, they may be the dominant source of cosmic ray electrons and positrons above about 30 GeV.

  1. Early history of cosmic ray studies

    NASA Astrophysics Data System (ADS)

    Sekido, Y.; Elliot, H.

    1985-07-01

    The early years of cosmic ray research are reviewed from a historical perspective. Consideration is given to: the balloon measurements of the cosmic ray background carried out by V.F. Hess in 1912; the early measurements of cosmic ray intensity as a function of latitude; and the discovery of the positron and the mesotron in the 1930s. The impact of various technologies (particle accelerators, satellites, and space probes) and the pace of discovery in the field of cosmic ray studies is examined in detail. Black and white photographs of the major contributors to cosmic ray studies over the last 70 years are provided.

  2. 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)

    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

    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*.

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

    NASA Astrophysics Data System (ADS)

    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, William W.

    2014-03-01

    We report the first detection of high-energy X-ray (E > 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 ~50 keV during a NuSTAR Galactic center monitoring campaign. The featureless power-law spectrum with a photon index ? ? 2.3 confirms a non-thermal emission mechanism. The observed flux in the 3-79 keV band is FX = (2.0 0.1) 10-12 erg cm-2 s-1, corresponding to an unabsorbed X-ray luminosity LX = (2.6 0.8) 1034 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 ~100 kyr) with low surface brightness and radii up to ~30 pc or MCs illuminated by cosmic rays (CRs) from CR accelerators such as SNRs or Sgr A*.

  4. Characterising CCDs with cosmic rays

    DOE PAGESBeta

    Fisher-Levine, M.; Nomerotski, A.

    2015-08-06

    The properties of cosmic ray muons make them a useful probe for measuring the properties of thick, fully depleted CCD sensors. The known energy deposition per unit length allows measurement of the gain of the sensor's amplifiers, whilst the straightness of the tracks allows for a crude assessment of the static lateral electric fields at the sensor's edges. The small volume in which the muons deposit their energy allows measurement of the contribution to the PSF from the diffusion of charge as it drifts across the sensor. In this work we present a validation of the cosmic ray gain measurementmore » technique by comparing with radioisotope gain measurments, and calculate the charge diffusion coefficient for prototype LSST sensors.« less

  5. Characterising CCDs with cosmic rays

    SciTech Connect

    Fisher-Levine, M.; Nomerotski, A.

    2015-08-06

    The properties of cosmic ray muons make them a useful probe for measuring the properties of thick, fully depleted CCD sensors. The known energy deposition per unit length allows measurement of the gain of the sensor's amplifiers, whilst the straightness of the tracks allows for a crude assessment of the static lateral electric fields at the sensor's edges. The small volume in which the muons deposit their energy allows measurement of the contribution to the PSF from the diffusion of charge as it drifts across the sensor. In this work we present a validation of the cosmic ray gain measurement technique by comparing with radioisotope gain measurments, and calculate the charge diffusion coefficient for prototype LSST sensors.

  6. The discovery of cosmic rays

    NASA Astrophysics Data System (ADS)

    Carlson, Per; de Angelis, Alessandro

    2011-04-01

    The work leading to the discovery of cosmic rays by Victor Hess on August 7, 1912 is reviewed. In particular the almost forgotten work of the Italian Dominico Pacini in 1909-10 is described. Hess was awarded the Nobel Prize in Physics 1936, shared with Carl Anderson for the discovery of the positron. The reason for the long delay is discussed as well as the nominations and discussions put forward in the Nobel Committee's report to the Royal Swedish Academy of Sciences.

  7. Note on the detection of high energy primary cosmic gamma rays by air shower observation

    NASA Technical Reports Server (NTRS)

    Kasahara, K.; Torii, S.; Yuda, T.

    1985-01-01

    A mountain altitude experiment is planned at Mt. Norikura in Japan to search for point sources of astrophysical high-energy gamma rays in the 10 to the 15th power eV range. The advantages of mountain level observation of IR showers is stressed, especially in the case of high-energy gamma primaries from Cygnus X3 and other similar point sources.

  8. Secondary antiprotons - A valuable cosmic-ray probe

    NASA Technical Reports Server (NTRS)

    Steigman, G.

    1977-01-01

    Even in the absence of antiprotons in the primary cosmic rays, a flux of secondary antiprotons will be produced in collisions between cosmic rays and interstellar gas. The predicted antiproton fraction increases with increasing cosmic-ray confinement, so that observations of antiprotons will provide a probe of models of cosmic-ray confinement. It is shown that the expected antiproton fraction (for energies of at least about 10 GeV) ranges between 0.00023 for the 'leaky box' model and 0.0018 for the 'closed box' model. In addition, attention is called to the fact that a detection of cosmic-ray antiprotons at or above a level of 0.0002 will provide a valuable lower limit to the antiproton lifetime.

  9. Evolution of Intracluster Cosmic Rays and Gamma-Ray Emission

    NASA Astrophysics Data System (ADS)

    Tsubaki, Shin-Ya; Kitayama, Tetsu; Sato, Katsuhiko

    2003-07-01

    The effect of merger history of clusters of galaxies on intra-cluster cosmic rays (ICCRs) is investigated. Though the effect of merger shock, which is responsible for (in-situ) acceleration of ICCRs, is ignored here, the effect of evolution is important for ICCRs and induced gamma-rays. Taking star formation history into account, we find 1) the gamma-ray flux from a cluster of galaxies is consistent with EGRET observation, and the detection by the GLAST is possible, and 2) the contribution of clusters of galaxies to the diffuse gamma-ray background is not so large, with reasonable parameter range.

  10. Cosmic-ray detector blasts off on space shuttle

    NASA Astrophysics Data System (ADS)

    Johnston, Hamish

    2011-06-01

    An instrument for detecting cosmic rays - and possibly even dark matter - has finally been lifted into orbit on board the Space Shuttle Endeavour and installed on the International Space Station (ISS).

  11. Study of multi-muon bundles in cosmic ray showers detected with the DELPHI detector at LEP

    NASA Astrophysics Data System (ADS)

    Delphi Collaboration; Abreu, P.; Adam, W.; Adzic, P.; Albrecht, T.; Alemany-Fernandez, R.; Allmendinger, T.; Allport, P. P.; Amaldi, U.; Amapane, N.; Amato, S.; Anashkin, E.; Andreazza, A.; Andringa, S.; Anjos, N.; Antilogus, P.; Apel, W.-D.; Arnoud, Y.; Ask, S.; Asman, B.; Augustinus, A.; Baillon, P.; Ballestrero, A.; Bambade, P.; Barbier, R.; Bardin, D.; Barker, G. J.; Baroncelli, A.; Battaglia, M.; Baubillier, M.; Becks, K.-H.; Begalli, M.; Behrmann, A.; Ben-Haim, E.; Benekos, N.; Benvenuti, A.; Berat, C.; Berggren, M.; Bertrand, D.; Besancon, M.; Besson, N.; Bloch, D.; Blom, M.; Bluj, M.; Bonesini, M.; Boonekamp, M.; Booth, P. S. L.; Borisov, G.; Botner, O.; Bouquet, B.; Bowcock, T. J. V.; Boyko, I.; Bracko, M.; Brenner, R.; Brodet, E.; Bruckman, P.; Brunet, J. M.; Buschbeck, B.; Buschmann, P.; Calvi, M.; Camporesi, T.; Canale, V.; Carena, F.; Castro, N.; Cavallo, F.; Chapkin, M.; Charpentier, Ph.; Checchia, P.; Chierici, R.; Chliapnikov, P.; Chudoba, J.; Chung, S. U.; Cieslik, K.; Collins, P.; Contri, R.; Cosme, G.; Cossutti, F.; Costa, M. J.; Crennell, D.; Cuevas, J.; D'Hondt, J.; da Silva, T.; da Silva, W.; Della Ricca, G.; de Angelis, A.; de Boer, W.; de Clercq, C.; de Lotto, B.; de Maria, N.; de Min, A.; de Paula, L.; di Ciaccio, L.; di Simone, A.; Doroba, K.; Drees, J.; Eigen, G.; Ekelof, T.; Ellert, M.; Elsing, M.; Espirito Santo, M. C.; Fanourakis, G.; Fassouliotis, D.; Feindt, M.; Fernandez, J.; Ferrer, A.; Ferro, F.; Flagmeyer, U.; Foeth, H.; Fokitis, E.; Fulda-Quenzer, F.; Fuster, J.; Gandelman, M.; Garcia, C.; Gavillet, Ph.; Gazis, E.; Gokieli, R.; Golob, B.; Gomez-Ceballos, G.; Goncalves, P.; Graziani, E.; Grosdidier, G.; Grzelak, K.; Guy, J.; Haag, C.; Hallgren, A.; Hamacher, K.; Hamilton, K.; Haug, S.; Hauler, F.; Hedberg, V.; Hennecke, M.; Herr, H.; Hoffman, J.; Holmgren, S.-O.; Holt, P. J.; Houlden, M. A.; Jackson, J. N.; Jarlskog, G.; Jarry, P.; Jeans, D.; Johansson, E. K.; Jonsson, P.; Joram, C.; Jungermann, L.; Kapusta, F.; Katsanevas, S.; Katsoufis, E.; Kernel, G.; Kersevan, B. P.; Kerzel, U.; King, B. T.; Kjaer, N. J.; Kluit, P.; Kokkinias, P.; Kourkoumelis, C.; Kouznetsov, O.; Krumstein, Z.; Kucharczyk, M.; Lamsa, J.; Leder, G.; Ledroit, F.; Leinonen, L.; Leitner, R.; Lemonne, J.; Lepeltier, V.; Lesiak, T.; Liebig, W.; Liko, D.; Lipniacka, A.; Lopes, J. H.; Lopez, J. M.; Loukas, D.; Lutz, P.; Lyons, L.; MacNaughton, J.; Malek, A.; Maltezos, S.; Mandl, F.; Marco, J.; Marco, R.; Marechal, B.; Margoni, M.; Marin, J.-C.; Mariotti, C.; Markou, A.; Martinez-Rivero, C.; Masik, J.; Mastroyiannopoulos, N.; Matorras, F.; Matteuzzi, C.; Mazzucato, F.; Mazzucato, M.; McNulty, R.; Meroni, C.; Migliore, E.; Mitaroff, W.; Mjoernmark, U.; Moa, T.; Moch, M.; Moenig, K.; Monge, R.; Montenegro, J.; Moraes, D.; Moreno, S.; Morettini, P.; Mueller, U.; Muenich, K.; Mulders, M.; Mundim, L.; Murray, W.; Muryn, B.; Myatt, G.; Myklebust, T.; Nassiakou, M.; Navarria, F.; Nawrocki, K.; Nicolaidou, R.; Nikolenko, M.; Oblakowska-Mucha, A.; Obraztsov, V.; Olshevski, A.; Onofre, A.; Orava, R.; Osterberg, K.; Ouraou, A.; Oyanguren, A.; Paganoni, M.; Paiano, S.; Palacios, J. P.; Palka, H.; Papadopoulou, Th. D.; Pape, L.; Parkes, C.; Parodi, F.; Parzefall, U.; Passeri, A.; Passon, O.; Peralta, L.; Perepelitsa, V.; Perrotta, A.; Petrolini, A.; Piedra, J.; Pieri, L.; Pierre, F.; Pimenta, M.; Piotto, E.; Podobnik, T.; Poireau, V.; Pol, M. E.; Polok, G.; Pozdniakov, V.; Pukhaeva, N.; Pullia, A.; Rames, J.; Read, A.; Rebecchi, P.; Rehn, J.; Reid, D.; Reinhardt, R.; Renton, P.; Richard, F.; Ridky, J.; Rivero, M.; Rodriguez, D.; Romero, A.; Ronchese, P.; Roudeau, P.; Rovelli, T.; Ruhlmann-Kleider, V.; Ryabtchikov, D.; Sadovsky, A.; Salmi, L.; Salt, J.; Sander, C.; Savoy-Navarro, A.; Schwickerath, U.; Sekulin, R.; Shellard, R. C.; Siebel, M.; Sisakian, A.; Smadja, G.; Smirnova, O.; Sokolov, A.; Sopczak, A.; Sosnowski, R.; Spassov, T.; Stanitzki, M.; Stocchi, A.; Strauss, J.; Stugu, B.; Szczekowski, M.; Szeptycka, M.; Szumlak, T.; Tabarelli, T.; Taffard, A. C.; Tegenfeldt, F.; Timmermans, J.; Tkatchev, L.; Tobin, M.; Todorovova, S.; Tome, B.; Tonazzo, A.; Tortosa, P.; Travnicek, P.; Treille, D.; Tristram, G.; Trochimczuk, M.; Troncon, C.; Turluer, M.-L.; Tyapkin, I. A.; Tyapkin, P.; Tzamarias, S.; Uvarov, V.; Valenti, G.; van Dam, P.; van Eldik, J.; van Remortel, N.; van Vulpen, I.; Vegni, G.; Veloso, F.; Venus, W.; Verdier, P.; Verzi, V.; Vilanova, D.; Vitale, L.; Vrba, V.; Wahlen, H.; Washbrook, A. J.; Weiser, C.; Wicke, D.; Wickens, J.; Wilkinson, G.; Winter, M.; Witek, M.; Yushchenko, O.; Zalewska, A.; Zalewski, P.; Zavrtanik, D.; Zhuravlov, V.; Zimin, N. I.; Zintchenko, A.; Zupan, M.

    2007-11-01

    The DELPHI detector at LEP has been used to measure multi-muon bundles originating from cosmic ray interactions with air. The cosmic events were recorded in “parasitic mode” between individual e+e- interactions and the total live time of this data taking is equivalent to 1.6 × 106 s. The DELPHI apparatus is located about 100 m underground and the 84 metres rock overburden imposes a cutoff of about 52 GeV/c on muon momenta. The data from the large volume Hadron Calorimeter allowed the muon multiplicity of 54,201 events to be reconstructed. The resulting muon multiplicity distribution is compared with the prediction of the Monte Carlo simulation based on CORSIKA/QGSJET01. The model fails to describe the abundance of high multiplicity events. The impact of QGSJET internal parameters on the results is also studied.

  12. SOLAR SYSTEM OBJECTS AS COSMIC RAYS DETECTORS

    SciTech Connect

    Privitera, P.; Motloch, P.

    2014-08-10

    In a recent Letter, Jupiter is presented as an efficient detector for Ultra-High Energy Cosmic Rays (UHECRs), through measurement by an Earth-orbiting satellite of gamma rays from UHECRs showers produced in Jupiter's atmosphere. We show that this result is incorrect, due to erroneous assumptions on the angular distribution of shower particles. We evaluated other solar system objects as potential targets for UHECRs detection, and found that the proposed technique is either not viable or not competitive with traditional ground-based UHECRs detectors.

  13. Earth's magnetic field as a radiator to detect cosmic ray electrons of energy greater than 10 to the 12th eV

    NASA Technical Reports Server (NTRS)

    Balasubrahmanyan, V. K.; Stephens, S. A.

    1983-01-01

    Synchrotron emission by a high-energy electron in the geomagnetic field and its dependence upon different arrival directions over Palestine, Texas, where major balloon-borne experiments are being conducted, is studied. The dependence of detector response on the arrival direction of electron, the different criteria which are adopted to identify an electron event, the area of the detector, and the energy of the electron are discussed. An omnidirectional circular detector is used to examine whether it is possible to determine the energy of an electron without knowing its arrival direction. The collecting power of a detector is estimated as a function of the energy of electrons for different detector areas with different selection criteria, and this information is used to calculate the event rates expected by folding in the energy spectrum of cosmic ray electrons to show the viability of detecting cosmic ray electrons at energies greater than a few TeV.

  14. High-energy X-ray detection of G359.89–0.08 (SGR A–E): Magnetic flux tube emission powered by cosmic rays?

    SciTech Connect

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

    2014-03-20

    We report the first detection of high-energy X-ray (E > 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 ∼50 keV during a NuSTAR Galactic center monitoring campaign. The featureless power-law spectrum with a photon index Γ ≈ 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{sup –12} erg cm{sup –2} s{sup –1}, corresponding to an unabsorbed X-ray luminosity L{sub X} = (2.6 ± 0.8) × 10{sup 34} erg s{sup –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 ∼100 kyr) with low surface brightness and radii up to ∼30 pc or MCs illuminated by cosmic rays (CRs) from CR accelerators such as SNRs or Sgr A*.

  15. Cloud chamber visualization of primary cosmic rays

    SciTech Connect

    Earl, James A.

    2013-02-07

    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.

  16. Solar modulation of galactic cosmic rays

    NASA Technical Reports Server (NTRS)

    Fisk, L. A.

    1980-01-01

    The current theory for the solar modulation of galactic cosmic rays is reviewed briefly. The four basic mechanisms which are important for modulation-diffusion, effects associated with the large-scale magnetic field, convection, and energy change - are discussed in simple terms. The equation which describes cosmic-ray behavior in the heliosphere is presented and some sample solutions are considered. It is pointed out that, although the basic mechanisms which describe the cosmic-ray behavior are understood, the actual cause of the variation in the cosmic-ray flux over the solar cycle, or over longer intervals, is beyond current comprehension.

  17. Cosmic Ray Acceleration in Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Blasi, P.

    2011-06-01

    We review the main observational and theoretical facts about acceleration of Galactic cosmic rays in supernova remnants, discussing the arguments in favor and against a connection between cosmic rays and supernova remnants, the so-called supernova remnant paradigm for the origin of Galactic cosmic rays. Recent developments in the modeling of the mechanism of diffusive shock acceleration are discussed, with emphasis on the role of 1) magnetic field amplification, 2) acceleration of nuclei heavier than hydrogen, 3) presence of neutrals in the circumstellar environment. The status of the supernova-cosmic ray connection in the time of Fermi-LAT and Cherenkov telescopes is also discussed.

  18. High-energy cosmic ray interactions

    SciTech Connect

    Engel, Ralph; Orellana, Mariana; Reynoso, Matias M.; Vila, Gabriela S.

    2009-04-30

    Research into hadronic interactions and high-energy cosmic rays are closely related. On one hand--due to the indirect observation of cosmic rays through air showers--the understanding of hadronic multiparticle production is needed for deriving the flux and composition of cosmic rays at high energy. On the other hand the highest energy particles from the universe allow us to study the characteristics of hadronic interactions at energies far beyond the reach of terrestrial accelerators. This is the summary of three introductory lectures on our current understanding of hadronic interactions of cosmic rays.

  19. Propagation of cosmic rays in the galaxy

    NASA Technical Reports Server (NTRS)

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

    1974-01-01

    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.

  20. Accretion Disks and Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Fowler, Ken

    2014-10-01

    We model accretion disks as Faraday disks with current and mass flows perpendicular to 2D mean field flux surfaces. We model jets produced by accretion disks as weakly-unstable current flows. We model cosmic ray acceleration arising from jet kink modes producing a runaway ion beam that finally accelerates itself by cyclotron resonance. All of these processes can be unified by an Ohm's Law in which Spitzer resistivity is replaced by a generalized hyper-resisitivity, ultimately yielding several predictions in rough agreement with observations.

  1. Cosmic Rays in the Heliosphere

    NASA Astrophysics Data System (ADS)

    Potgieter, M. S.

    The international heliospheric year (IHY) has the purpose to promote research on the Sun-Heliosphere system outward to the local interstellar medium - the new frontier. This includes fostering international scientific cooperation in the study of heliophysical phenomena now and in the future. Part of this process is to communicate research done on the heliosphere, especially to the scientific community in Africa. A short review is given of the numerical modeling of the heliosphere, and of the modulation of cosmic rays and how these particles are used to probe the heliosphere to understand its basic features. Projects of both a theoretical and numerical nature are proposed for the IHY.

  2. A balloon-borne ionization spectrometer with very large aperture for the detection of high energy cosmic rays

    NASA Technical Reports Server (NTRS)

    Atallah, K.; Modlinger, A.; Schmidt, W. K. H.; Cleghorn, T. F.

    1975-01-01

    A balloon experiment which was used to determine the chemical composition of very high-energy cosmic rays up to and beyond 100 GeV/nucleon is described. The detector had a geometric factor of 1 sq m sr and a total weight on the balloon of 2100 kg. The apparatus consisted of an ionization spectrometer, spark chambers, and plastic scintillation and Cherenkov counters. It was calibrated at CERN up to 24 GeV/c protons and at DESY up to 7 GeV/c electrons. In October 1972 it was flown successfully on a stratospheric balloon.

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

    NASA Technical Reports Server (NTRS)

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

    1975-01-01

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

  4. Cosmic Ray Energetics and Mass (CREAM)

    NASA Technical Reports Server (NTRS)

    Coutu, Stephane

    2005-01-01

    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.

  5. Launch in Orbit of NINA detector for cosmic ray study

    NASA Astrophysics Data System (ADS)

    Marco, Casolino

    The apparatus NINA, on board the Russian satellite Resurs-O1 n.4, is in orbit since July 10th, 1998. Its scientific scope is to study the low energy component of cosmic ray nuclei. The polar orbit of the satellite allows the telescope to detect particles of different nature during its revolution: galactic cosmic rays, solar energetic particles, trapped and untrapped anomalous cosmic rays. We report here about the launch phase and present some preliminary results obtained with the first months of life in space of the detector.

  6. Geomagnetically trapped anomalous cosmic rays

    SciTech Connect

    Selesnick, R.S.; Cummings, A.C.; Cummings, J.R.

    1995-06-01

    Since its launch in July 1992, the polar-orbiting satellite SAMPEX has been collecting data on geomagnetically trapped heavy ions, predominantly O, N, and Ne, at energies {ge}15 MeV/nucleon and in a narrow L shell range L = 2. Their location, elemental composition, energy spectra, pitch angle distribution, and time variations all support the theory that these particles originated as singly ionized interplanetary anomalous cosmic rays that were stripped of electrons in the Earth`s upper atmosphere and subsequently trapped. The O are observed primarily at pitch angles outside the atmospheric loss cones, consistent with a trapped population, and their distribution there is nearly isotropic. The abundances relative to O of the N, possible Ne, and especially C are lower than the corresponding interplanetary values, which may be indicative of the trapping efficiencies. The distributions of trapped N, O, and Ne in energy and L shell suggest that most of the ions observed at the SAMPEX altitude of {approximately}600 km are not fully stripped when initially trapped. A comparison of the trapped intensity with the much lower interplanetary intensity of anomalous cosmic rays provides model-dependent estimates of the product of the trapping probability and the average trapped particle lifetime against ionization losses in the residual atmosphere for particles that mirror near the SAMPEX altitude. 36 refs., 13 figs., 1 tab.

  7. Cosmic rays and space weather

    NASA Astrophysics Data System (ADS)

    Dorman, L. I.

    2003-04-01

    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.

  8. Antiprotons from thick cosmic-ray sources

    NASA Astrophysics Data System (ADS)

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

    1985-06-01

    The authors examine the possibility of explaining the cosmic-ray antiproton flux observed by adding thick cosmic-ray sources to the thin sources of the standard leaky-box model. They show that in this model, if all cosmic rays issue from these sources, the mean thick-source grammage needed to account for the observed antiproton flux is only ≡7.5 g cm-2. However, thick sources will overproduce secondary cosmic-ray nuclei such as lithium, beryllium, boron if their grammage is less than ≡30 g cm-2. With this grammage, the fraction of cosmic rays coming from thick sources is ≡25%. The amounts of other thick-source products predicted by the model are also evaluated: deuterons, helium 3, interstellar lithium, beryllium and boron, positrons, gamma-rays and neutrinos.

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  10. Cosmic-ray propagation and containment

    NASA Technical Reports Server (NTRS)

    Parker, E. N.

    1977-01-01

    The cosmic rays are an active gaseous component of the disk of the galaxy, and their propagation and containment is a part of the general dynamics of the disk. The sources of cosmic rays are a matter of speculation. The disk is inflated by the cosmic-ray gas pressure, P, comparable to the magnetic pressure B super 2/ 8 pi, but the rate of inflation is unknown. The time spent by the individual cosmic-ray particles in the disk is inversely proportional to the cosmic-ray production rate and may be anything from 100,000 to more than 10 million years. It is evident from the decay of Be(10) that the cosmic rays circulate through a volume of space perhaps ten times the thickness of the gaseous disk, suggesting a magnetic halo extending out approximately 1 kpc from either face of the disk. The cosmic rays may be responsible for the halo by inflating the magnetic fields of the disk. Extension of the fields to 1 kpc would imply a high production rate and short life of cosmic rays in the dense gaseous disk of the galaxy.

  11. Early history of cosmic rays at Chicago

    NASA Astrophysics Data System (ADS)

    Yodh, Gaurang B.

    2013-02-01

    Cosmic ray studies at the University of Chicago were started by Arthur Compton during the late 1920s. The high points of cosmic ray studies at Chicago under Compton and Marcel Schein are the focus of this report, which summarizes the research done at Chicago up to the end of World War II.

  12. Origin of Galactic Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Blasi, Pasquale

    2013-06-01

    The origin of the bulk of cosmic rays (CRs) observed at Earth is the topic of a century long investigation, paved with successes and failures. From the energetic point of view, supernova remnants (SNRs) remain the most plausible sources of CRs up to rigidity ˜106-107 GV. This confidence somehow resulted in the construction of a paradigm, the so-called SNR paradigm: CRs are accelerated through diffusive shock acceleration in SNRs and propagate diffusively in the Galaxy in an energy dependent way. Qualitative confirmation of the SNR acceleration scenario has recently been provided by gamma ray and X-ray observations. Diffusive propagation in the Galaxy is probed observationally through measurement of the secondary to primary nuclei flux ratios (such as B/C). There are however some weak points in the paradigm, which suggest that we are probably missing some physical ingredients in our models. The theory of diffusive shock acceleration at SNR shocks predicts spectra of accelerated particles which are systematically too hard compared with the ones inferred from gamma ray observations. Moreover, hard injection spectra indirectly imply a steep energy dependence of the diffusion coefficient in the Galaxy, which in turn leads to anisotropy larger than the observed one. Moreover recent measurements of the flux of nuclei suggest that the spectra have a break at rigidity ˜200 GV, which does not sit well with the common wisdom in acceleration and propagation. In this paper I will review these new developments and suggest some possible implications.

  13. Research in cosmic and gamma ray astrophysics

    NASA Technical Reports Server (NTRS)

    Stone, E. C.; Davis, L., Jr.; Mewaldt, R. A.; Prince, T. A.

    1989-01-01

    Research activities in cosmic rays, gamma rays, and astrophysical plasmas are covered. The activities are divided into sections and described, followed by a bibliography. The astrophysical aspects of cosmic rays, gamma rays, and of the radiation and electromagnetic field environment of the Earth and other planets are investigated. These investigations are performed by means of energetic particle and photon detector systems flown on spacecraft and balloons.

  14. Cosmic-Ray Modulation Equations

    NASA Astrophysics Data System (ADS)

    Moraal, H.

    2013-06-01

    The temporal variation of the cosmic-ray intensity in the heliosphere is called cosmic-ray modulation. The main periodicity is the response to the 11-year solar activity cycle. Other variations include a 27-day solar rotation variation, a diurnal variation, and irregular variations such as Forbush decreases. General awareness of the importance of this cosmic-ray modulation has greatly increased in the last two decades, mainly in communities studying cosmogenic nuclides, upper atmospheric physics and climate, helio-climatology, and space weather, where corrections need to be made for these modulation effects. Parameterized descriptions of the modulation are even used in archeology and in planning the flight paths of commercial passenger jets. The qualitative, physical part of the modulation is generally well-understood in these communities. The mathematical formalism that is most often used to quantify it is the so-called Force-Field approach, but the origins of this approach are somewhat obscure and it is not always used correct. This is mainly because the theory was developed over more than 40 years, and all its aspects are not collated in a single document. This paper contains a formal mathematical description intended for these wider communities. It consists of four parts: (1) a description of the relations between four indicators of "energy", namely energy, speed, momentum and rigidity, (2) the various ways of how to count particles, (3) the description of particle motion with transport equations, and (4) the solution of such equations, and what these solutions mean. Part (4) was previously described in Caballero-Lopez and Moraal (J. Geophys. Res, 109: A05105, doi: 10.1029/2003JA010358, 2004). Therefore, the details are not all repeated here. The style of this paper is not to be rigorous. It rather tries to capture the relevant tools to do modulation studies, to show how seemingly unrelated results are, in fact, related to one another, and to point out the historical context of some of the results. The paper adds no new knowledge. The summary contains advice on how to use the theory most effectively.

  15. Propagation of cosmic rays in the Galaxy

    NASA Technical Reports Server (NTRS)

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

    1975-01-01

    The galactic model of cosmic ray confinement is assumed in an in-depth theoretical investigation of cosmic ray propagation in the Galaxy, with consideration also given to the interpretation of observed data. The necessary data concerning the interstellar medium are summarized in order to form a basis for the theoretical formulation of the propagation of cosmic rays, which are assumed to be in a state of equilibrium and homogeneously distributed in the residence volume. The interaction of cosmic rays with the attenuated gases, weak magnetic fields, and radiation fields of the interstellar medium is examined. Many of these interactions lead to the production of radiations ranging the entire electromagnetic spectrum. The possible roles played by cosmic rays in some aspects of galactic dynamics such as the hydrostatic equilibrium of interstellar gas, gravitational instability and formation of clouds, and heating of interstellar gas, are also studied.

  16. High energy physics in cosmic rays

    SciTech Connect

    Jones, Lawrence W.

    2013-02-07

    In the first half-century of cosmic ray physics, the primary research focus was on elementary particles; the positron, pi-mesons, mu-mesons, and hyperons were discovered in cosmic rays. Much of this research was carried out at mountain elevations; Pic du Midi in the Pyrenees, Mt. Chacaltaya in Bolivia, and Mt. Evans/Echo Lake in Colorado, among other sites. In the 1960s, claims of the observation of free quarks, and satellite measurements of a significant rise in p-p cross sections, plus the delay in initiating accelerator construction programs for energies above 100 GeV, motivated the Michigan-Wisconsin group to undertake a serious cosmic 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.

  17. Anisotropy and corotation of galactic cosmic rays.

    PubMed

    Amenomori, M; Ayabe, S; Bi, X J; Chen, D; Cui, S W; Danzengluobu; Ding, L K; Ding, X H; Feng, C F; Feng, Zhaoyang; Feng, Z Y; Gao, X Y; Geng, Q X; Guo, H W; He, H H; He, M; Hibino, K; Hotta, N; Hu, Haibing; Hu, H B; Huang, J; Huang, Q; Jia, H Y; Kajino, F; Kasahara, K; Katayose, Y; Kato, C; Kawata, K; Labaciren; Le, G M; Li, A F; Li, J Y; Lou, Y-Q; Lu, H; Lu, S L; Meng, X R; Mizutani, K; Mu, J; Munakata, K; Nagai, A; Nanjo, H; Nishizawa, M; Ohnishi, M; Ohta, I; Onuma, H; Ouchi, T; Ozawa, S; Ren, J R; Saito, T; Saito, T Y; Sakata, M; Sako, T K; Sasaki, T; Shibata, M; Shiomi, A; Shirai, T; Sugimoto, H; Takita, M; Tan, Y H; Tateyama, N; Torii, S; Tsuchiya, H; Udo, S; Wang, B; Wang, H; Wang, X; Wang, Y G; Wu, H R; Xue, L; Yamamoto, Y; Yan, C T; Yang, X C; Yasue, S; Ye, Z H; Yu, G C; Yuan, A F; Yuda, T; Zhang, H M; Zhang, J L; Zhang, N J; Zhang, X Y; Zhang, Y; Zhang, Yi; Zhaxisangzhu; Zhou, X X

    2006-10-20

    The intensity of Galactic cosmic rays is nearly isotropic because of the influence of magnetic fields in the Milky Way. Here, we present two-dimensional high-precision anisotropy measurement for energies from a few to several hundred teraelectronvolts (TeV), using the large data sample of the Tibet Air Shower Arrays. Besides revealing finer details of the known anisotropies, a new component of Galactic cosmic ray anisotropy in sidereal time is uncovered around the Cygnus region direction. For cosmic-ray energies up to a few hundred TeV, all components of anisotropies fade away, showing a corotation of Galactic cosmic rays with the local Galactic magnetic environment. These results have broad implications for a comprehensive understanding of cosmic rays, supernovae, magnetic fields, and heliospheric and Galactic dynamic environments. PMID:17053141

  18. Cosmic Connections:. from Cosmic Rays to Gamma Rays, Cosmic Backgrounds and Magnetic Fields

    NASA Astrophysics Data System (ADS)

    Kusenko, Alexander

    2013-12-01

    Combined data from gamma-ray telescopes and cosmic-ray detectors have produced some new surprising insights regarding intergalactic and galactic magnetic fields, as well as extragalactic background light. We review some recent advances, including a theory explaining the hard spectra of distant blazars and the measurements of intergalactic magnetic fields based on the spectra of distant sources. Furthermore, we discuss the possible contribution of transient galactic sources, such as past gamma-ray bursts and hypernova explosions in the Milky Way, to the observed ux of ultrahigh-energy cosmicrays nuclei. The need for a holistic treatment of gamma rays, cosmic rays, and magnetic fields serves as a unifying theme for these seemingly unrelated phenomena.

  19. Cosmic rays: a review for astrobiologists.

    PubMed

    Ferrari, Franco; Szuszkiewicz, Ewa

    2009-05-01

    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

  20. Gamma Rays, Cosmic Rays, and Extinct Radioactivity in Molecular Clouds

    NASA Astrophysics Data System (ADS)

    Clayton, Donald D.; Jin, Liping

    1995-10-01

    We investigate causal connection between two astonishingly big numbers: the very large 26Al concentration (5 × 10-5 of 27Al) in the early solar system and the very large nuclear excitation rate in Orion clouds. We present three separate pictures attributing 26Al within the early solar system and other molecular cloud cores to special cosmic-ray irradiation of those cloud cores. These pictures reinterpret the large 26Al/27Al ratio found in the early solar accretion disk, and seem not to be relevant to the present interstellar 1.5 Msun of 26Al. These three pictures of cosmic-ray irradiation of molecular clouds accounting for their high 26Al content are: 1. High flux of low-energy cosmic ray 0, Na, Mg, and Si nuclei stopping in the clouds with partial conversion to 26Al by nuclear interactions while they stop (Clayton 1994); 2. Stopping of low-energy galactic cosmic rays, which are known (at 100 MeV nucleon-1) to carry the very large activity 26Al/27Al = 0.1 and which we argue to be absorbed by cloud cores; 3. Stopping of newly synthesized particles accelerated from local ejecta of supernovae and W-R star winds, which carry activities as great as 26Al/27Al = 0.01 from those events. In these pictures the cosmic rays may be very different in origin than the galactic cosmic rays. At low energy they are injected into clouds and stopped in the cloud cores. We normalize our expectations for massive clouds to the inelastic nuclear excitation rates of 12C*(4.43 MeV) and 16O*(6.13 MeV) gamma rays emerging from the clouds in Orion (Bloemen et al. 1994). Picture 1 is plagued by very large power requirements if the accelerated particles are predominantly hydrogen. Nonetheless, we show that several other extinct radioactivity concentrations that accompanied 26Al in the early solar system would be coproduced by ordinary cosmic-ray composition. Our most promising construction of picture 1 appears to be anomalous acceleration of 16O ions (as known from the solar wind) to several MeV nucleon-1, resulting in both 4.43 and 6.13 MeV gamma ray lines and 12C(16O, pn)26Al in the clouds. Those ions ease the risk of producing too much 53Mn, which plagues each picture unless proton bombardment is suppressed by the acceleration mechanism. We confirm that overabundance of 9Be in solar matter also plagues irradiations producing 26Al within it unless those energies are less than about 10 MeV nucleon-1. We motivate each of these pictures by advancing a magnetized raisin-pudding model of molecular clouds and their embedded cores. The model suggests that both the nuclear interactions and the stopping of the ions occur preferentially within the dense cores of molecular clouds, which causes those cores to accumulate larger 26Al/27Al ratios than does the bulk of the molecular clouds. We argue that cosmic rays from OB associations drive the turbulence within molecular clouds near them. It is possible that these processes, rather than fresh radioactivity ejected from stars, cause star-forming regions to contain several of the extinct radioactivities near levels found in the early solar system. A new chapter in the relationship of OB associations and cosmic rays to the origins of solar systems has been opened by the COMPTEL detection.

  1. SLAC Cosmic Ray Telescope Facility

    SciTech Connect

    Va'vra, J.

    2010-02-15

    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.

  2. The Voyager Cosmic Ray Experiment

    NASA Technical Reports Server (NTRS)

    Stilwell, D. E.; Davis, W. D.; Joyce, R. M.; Mcdonald, F. B.; Trainor, J. H.; Althouse, W. E.; Cummings, A. C.; Garrard, T. L.; Stone, E. C.; Vogt, R. E.

    1979-01-01

    The Voyager Cosmic Ray Experiment includes seven dE/dx-E telescopes to measure the energy and charge of particles with atomic numbers from 1 to 26 in the energy range 1-500 MeV/nucleon and to measure electron energy in the range from 3 to 110 MeV. Isotopic composition of hydrogen through sulfur in the range up to 75 Mev/nucleon can also be resolved. The electronic systems include a dual-gain, charge sensitive preamplifier, 4096-channel pulse height analyzers for three parameter analysis of selected events, and an event type readout polling scheme to maximize the use of available telemetry space and to enhance the occurrence of rare events in the data. Details of the detector, electronic and mechanical design are presented.

  3. Galactic and solar cosmic rays - Variations and origin

    NASA Astrophysics Data System (ADS)

    Belov, A. V.; Blokh, Ia. L.; Gushchina, R. T.; Dorman, I. V.; Dorman, L. I.

    Past and current research efforts at IZMIRAN (the Soviet Institute for the Study of Terrestrial Magnetism, the Ionosphere, and the Propagation of Radio Waves) on galactic and solar cosmic rays is reviewed. Particular attention is given to investigations of penumbra effects manifested in cosmic rays, long-term cosmic-ray variations, cosmic-ray anisotropy, cosmic-ray fluctuations, the possible relationship between cosmic-ray variations and atmospheric ozone, the stellar anisotropy of cosmic rays, and cosmic-ray propagation in the interstellar medium.

  4. Explaining TeV Cosmic-Ray Anisotropies with Non-diffusive Cosmic-Ray Propagation

    NASA Astrophysics Data System (ADS)

    Harding, J. Patrick; Fryer, Chris L.; Mendel, Susan

    2016-05-01

    Constraining the behavior of cosmic ray data observed at Earth requires a precise understanding of how the cosmic rays propagate in the interstellar medium. The interstellar medium is not homogeneous; although turbulent magnetic fields dominate over large scales, small coherent regions of magnetic field exist on scales relevant to particle propagation in the nearby Galaxy. Guided propagation through a coherent field is significantly different from random particle diffusion and could be the explanation of spatial anisotropies in the observed cosmic rays. We present a Monte Carlo code to propagate cosmic particle through realistic magnetic field structures. We discuss the details of the model as well as some preliminary studies which indicate that coherent magnetic structures are important effects in local cosmic-ray propagation, increasing the flux of cosmic rays by over two orders of magnitude at anisotropic locations on the sky. The features induced by coherent magnetic structure could be the cause of the observed TeV cosmic-ray anisotropy.

  5. Cosmic-ray exposure ages of chondrules

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

    If chondrules were exposed to cosmic rays prior to meteorite compaction, they should retain an excess of cosmogenic noble gases. Beyersdorf-Kuis et al. showed that such excesses can be detected provided that the chemical composition of each individual chondrule is precisely known. However, their study was limited to a few samples as they had to be irradiated in a nuclear reactor for instrumental neutron activation analysis. We developed a novel analytical protocol that combines the measurements of He and Ne isotopic concentrations with a fast method to correct for differences in chemical composition using micro X-ray computed tomography. Our main idea is to combine noble gas, nuclear track, and petrography data for numerous chondrules to understand the precompaction exposure history of the chondrite parent bodies. Here, we report our results for a total of 77 chondrules and four matrix samples from NWA 8276 (L3.00), NWA 8007 (L3.2), and Bjurböle (L/LL4). All chondrules from the same meteorite have within uncertainty identical 21Ne exposure ages, and all chondrules from Bjurböle have within uncertainty identical 3He exposure ages. However, most chondrules from NWA 8276 and a few from NWA 8007 show small but resolvable differences in 3He exposure age that we attribute to matrix contamination and/or gas loss. The finding that none of the chondrules has noble gas excesses is consistent with the uniform track density found for each meteorite. We conclude that the studied chondrules did not experience a precompaction exposure longer than a few Ma assuming present-day flux of galactic cosmic rays. A majority of chondrules from L and LL chondrites thus rapidly accreted and/or was efficiently shielded from cosmic rays in the solar nebula.

  6. 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)

    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

    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.

  7. Cosmic gamma rays from quasars

    NASA Technical Reports Server (NTRS)

    Lau, M. M.; Young, E. C. M.

    1985-01-01

    The diffuse gamma radiation consists of the galactic and extragalactic components. The latter component is of special interest on account of its cosmological significance. Following the method recently proposed to estimate the gamma ray flux from galaxy clusters, and the detection of gamma rays from the quasars 3C273, the data base of the SAS II satellite was used to estimate the contribution from quasars to the extragalactic gamma ray flux. It is shown that quasars as a whole are significant gamma ray contributors, the average gamma ray flux per quasar in the energy range 35 MeV to 100 Mev being (1.3 + or - 0.9) x .00001 cm(-2)s(-1)sr(-1).

  8. EDITORIAL: Focus on High Energy Cosmic Rays FOCUS ON HIGH ENERGY COSMIC RAYS

    NASA Astrophysics Data System (ADS)

    Teshima, Masahiro; Watson, Alan A.

    2009-06-01

    The topic of high-energy cosmic rays has recently attracted significant attention. While the AGASA and HiRes Observatories have closed after many years of successful operation, the Pierre Auger Observatory began taking data in January 2004 and the first results have been reported. Plans for the next generation of instruments are in hand: funding is now being sought for the northern phase of the Auger Observatory and plans for a space detector, JEM-EUSO, to be launched in 2013-14 are well advanced with the long-term target of a dedicated satellite for the 2020s. It therefore seemed an appropriate time to make a collection of outstanding and original research articles from the leading experimental groups and from some of the theorists who seek to interpret the hard-won data and to speculate on the origin of the highest energy cosmic rays. This focus issue in New Journal of Physics on the topic of high energy cosmic rays, contains a comprehensive account of the work of the Yakutsk group (A A Ivanov, S P Knurenko and I Ye Sleptsov) who have used Cerenkov radiation produced by shower particles in the air to provide the basis for energy calibration. This technique contrasts with that of detecting fluorescence radiation from space that is proposed for the JEM-EUSO instrument to be placed on the International Space Station in 2013, described by Y Takahashi. Supplementing this is an article by A Santangelo and A Petrolini describing the scientific goals, requirements and main instrument features of the Super Extreme Universe Space Observatory mission (S-EUSO). The use of fluorescence light to measure energies was the key component of the HiRes instrument and is also used extensively by the Pierre Auger Collaboration so an article, by F Arqueros, F Blanco and J Rosado, summarizing the properties of fluorescence emission, still not fully understood, is timely. M Nagano, one of the architects of the AGASA Observatory, has provided an overview of the experimental situation with regard to the energy spectrum of the highest energy cosmic rays. The remaining contributions are of a more theoretical nature and discuss propagation (T Stanev), the time structure of multi-messenger signals (G H W Sigl), ultra-high energy cosmic ray production near black holes (A Yu Neronov, D V Semikoz and I I Tkachev), production in jets associated with black holes (C D Dermer, S Razzaque, J Finke and A Atoyan) and emission from a specific object, Cen A (M Kachelriess, S S Ostapchenko and R Tomas). Additionally the potential of high energy cosmic rays to give information about features of hadronic interactions, specifically the cross-section for p-air collisions, is discussed in the paper by R Ulrich et al. We thank all our authors most sincerely for their efforts and Tim Smith and his editorial team for their hard work. We believe that this collection of articles will be of great value to workers in the field: further contributions to this focus issue will be published during the course of 2009. Focus on High Energy Cosmic Rays Contents The cosmic ray energy spectrum as measured using the Pierre Auger Observatory Giorgio Matthiae The northern site of the Pierre Auger Observatory Johannes Blümer and the Pierre Auger Collaboration Searching for new physics with ultrahigh energy cosmic rays Floyd W Stecker and Sean T Scully On the measurement of the proton-air cross section using air shower data R Ulrich, J Blümer, R Engel, F Schüssler and M Unger High energy radiation from Centaurus A M Kachelrieß, S Ostapchenko and R Tomàs Ultra-high-energy cosmic rays from black hole jets of radio galaxies C D Dermer, S Razzaque, J D Finke and A Atoyan Ultra-high energy cosmic ray production in the polar cap regions of black hole magnetospheres A Yu Neronov, D V Semikoz and I I Tkachev Time structure and multi-messenger signatures of ultra-high energy cosmic ray sources Günter Sigl Propagation of ultrahigh-energy cosmic rays Todor Stanev Search for the end of the energy spectrum of primary cosmic rays M Nagano Analysis of the fluorescence emission from atmospheric nitrogen by electron excitation, and its application to fluorescence telescopes F Arqueros, F Blanco and J Rosado Observing ultra-high-energy cosmic particles from space: S-EUSO, the Super-Extreme Universe Space Observatory Mission A Santangelo and A Petrolini The JEM-EUSO mission Yoshiyuki Takahashi and the JEM-EUSO Collaboration Measuring extensive air showers with Cherenkov light detectors of the Yakutsk array: the energy spectrum of cosmic rays A A Ivanov, S P Knurenko and I Ye Sleptsov

  9. A theory of cosmic rays

    NASA Astrophysics Data System (ADS)

    Dar, Arnon; de Rújula, A.

    2008-09-01

    We present a theory of non-solar cosmic rays (CRs) in which the bulk of their observed flux is due to a single type of CR source at all energies. The total luminosity of the Galaxy, the broken power-law spectra with their observed slopes, the position of the ‘knee(s)’ and ‘ankle’, and the CR composition and its variation with energy are all predicted in terms of very simple and completely ‘standard’ physics. The source of CRs is extremely ‘economical’: it has only one parameter to be fitted to the ensemble of all of the mentioned data. All other inputs are ‘priors’, that is, theoretical or observational items of information independent of the properties of the source of CRs, and chosen to lie in their pre-established ranges. The theory is part of a ‘unified view of high-energy astrophysics’ — based on the ‘Cannonball’ model of the relativistic ejecta of accreting black holes and neutron stars. The model has been extremely successful in predicting all the novel properties of Gamma Ray Bursts recently observed with the help of the Swift satellite. If correct, this model is only lacking a satisfactory theoretical understanding of the ‘cannon’ that emits the cannonballs in catastrophic processes of accretion.

  10. Gamma-ray astronomy and the origin of cosmic rays

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1978-01-01

    Recent observations of cosmic gamma radiation are reviewed. It is shown that this radiation consists of an extragalactic background as well as a bright band of galactic radiation lying in the plane of the Milky Way and produced primarily by cosmic-ray collisions with interstellar gas atoms. The galactic gamma radiation is divided into a near component apparently associated with Gould's belt and a far component originating about 15,000 light years away and narrowly confined to the galactic plane. A Great Galactic Ring is identified which is 35,000 light years in diameter and in which most galactic cosmic rays are produced and supernovae and pulsars are concentrated. The physical mechanisms responsible for the production of most of the cosmic gamma rays in the Galaxy are examined, and the origin of galactic cosmic rays is considered. It is concluded that the cosmic rays are produced either in supernova explosions or in the pulsars they leave behind

  11. Optical and Ionization Basic Cosmic Ray Detector

    NASA Astrophysics Data System (ADS)

    Felix, Julian; Andrade, Diego A.; Araujo, Aurora C.; Arceo, Luis; Cervantes, Carlos A.; Molina, Jorge A.; Palacios, Luz R.

    2014-03-01

    There are drift tubes, operating in the Geiger mode, to detect ionization radiation and there are Cerenkov radiation detectors based on photomultiplier tubes. Here is the design, the construction, the operation and the characterization of a hybrid detector that combines both a drift tube and a Cerenkov detector, used mainly so far to detect cosmic rays. The basic cell is a structural Aluminum 101.6 cm-long, 2.54 cm X 2.54 cm-cross section, 0.1 cm-thick tube, interiorly polished to mirror and slightly covered with TiCO2, and filed with air, and Methane-Ar at different concentrations. There is a coaxial 1 mil Tungsten wire Au-coated at +700 to +1200 Volts electronically instrumented to read out in both ends; and there is in each end of the Aluminum tube a S10362-11-100U Hamamatsu avalanche photodiode electronically instrumented to be read out simultaneously with the Tungsten wire signal. This report is about the technical operation and construction details, the characterization results and potential applications of this hybrid device as a cosmic ray detector element. CONACYT, Mexico.

  12. Superdiffusion of cosmic rays: Implications for cosmic ray acceleration

    SciTech Connect

    Lazarian, A.; Yan, Huirong

    2014-03-20

    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 and 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 {sup 3} for freely streaming CRs. The dependence changes to x {sup 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.

  13. Galactic cosmic ray flux simulation and prediction.

    PubMed

    Nymmik, R A; Panasyuk, M I; Suslov, A A

    1996-01-01

    A dynamic galactic cosmic ray model is proposed to quantitatively describe the z=1-28 ions and electrons of E=10-10(5) MeV/nucleon and their particle flux variations around the Earth's orbit and beyond the Earth's magnetosphere due to diverse large-scale variations of solar activity factors. The variations of large-scale heliospheric magnetic fields and the galactic cosmic ray flux variation time delays relative to solar activity variations are simulated. The lag characteristics and sunspot number predictions having been determined in detail, the model can be used to predict galactic cosmic ray flux levels. PMID:11540366

  14. Cosmic ray propagation in the local superbubble

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    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.

  15. Cosmic ray propagation in the local superbubble

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    It is suggested that a ring of HI gas lying in the galactic plane is part of a supershell which formed some 3 x 10 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.

  16. The isotopic composition of cosmic ray chlorine

    NASA Technical Reports Server (NTRS)

    Wiedenbeck, M. E.

    1985-01-01

    The isotopic composition of galactic cosmic ray chlorine (approx. = 225 MeV/amu) has been studied using the high energy cosmic ray experiment on the International Sun Earth Explorer 3 (ISEE-3) spacecraft. The abundances of 35C1 and 37C1 are found to be consistent with the secondary production expected from a propagation model developed to account for both light and subiron secondaries. An upper limit on the abundance of the radioactive isotope 36C1 (halflife approx. = 0.3 Myr) is used to set a lower limit on the confinement time of cosmic rays of approximately 1 Myr.

  17. Cosmic Rays Variations and Human Physiological State

    NASA Astrophysics Data System (ADS)

    Dimitrova, S.

    2009-12-01

    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.

  18. Solar modulation. [of galactic cosmic rays

    NASA Technical Reports Server (NTRS)

    Fisk, L. A.

    1974-01-01

    The important aspects of solar modulation of galactic cosmic rays are outlined. The conditions in the interplanetary medium that affect the modulation are summarized, and equations are developed to describe the behavior of cosmic rays in the solar system, including the effects of diffusion, convection, and energy loss due to adiabatic deceleration in the expanding solar wind. The particle diffusion coefficient is determined from the power spectra of interplanetary magnetic field irregularities. After some solutions for the modulation equations have been derived, the probable forms of the unmodulated cosmic ray spectra are discussed. Other topics include solar cycle variations, energy loss effects, anisotrophies, and gradients.

  19. The Astrophysics of Galactic Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Diehl, R.; Kallenbach, R.; Parizot, E.; Von Steiger, R.

    2001-10-01

    Observations of cosmic rays and their related radio to gamma-ray signatures are surveyed and discussed critically, and compared to theoretical models of the cosmic-ray origin and propagation. The analogous heliospheric processes are included as a well-studied case of the principal physical processes of energetic particle acceleration and propagation. Reinforcements, or conflicts, in the interpretations of cosmic-ray spectral and compositional characteristics arise when cosmic-ray source and propagation models are confronted with astronomical information about the Galaxy as a whole and from potential source sites, i.e., supernova remnants or regions with high massive-star density. This volume represents the outcome of two workshops held at ISSI. In this chapter we summarize the introductory papers presented below, and include insights from the workshop discussions.

  20. Galactic gamma rays and the cosmic-ray halo problem

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.; Jones, F. C.

    1977-01-01

    Detailed models of diffused halos of various sizes are considered. In such models, the scale perpendicular to the plane has a strong effect in determining the distribution of cosmic rays. Radial distributions were calculated for cylindrical coordinate models. The implied gamma-ray longitude distributions were then calculated and compared with the SAS-2 data. Assuming the sources to be supernova remnants or pulsars, only cosmic-ray nucleon halo models with an upper limit scale height of about 3 kpc provide a good fit to the gamma ray data. Consideration of the gamma-ray latitude data gives a half thickness of 2 + or - 2 kpc for the cosmic ray electron halo.

  1. DISTINGUISHING SPONTANEOUS FISSION NEUTRONS FROM COSMIC-RAY BACKGROUND.

    SciTech Connect

    FORMAN,L.

    2004-08-02

    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.

  2. Consistency of cosmic-ray source abudances with explosive nucleosynthesis

    NASA Technical Reports Server (NTRS)

    Kozlovsky, B.; Ramaty, R.

    1973-01-01

    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.

  3. A Simplified Model for the Acceleration of Cosmic Ray Particles

    ERIC Educational Resources Information Center

    Gron, Oyvind

    2010-01-01

    Two important questions concerning cosmic rays are: Why are electrons in the cosmic rays less efficiently accelerated than nuclei? How are particles accelerated to great energies in ultra-high energy cosmic rays? In order to answer these questions we construct a simple model of the acceleration of a charged particle in the cosmic ray. It is not

  4. A Simplified Model for the Acceleration of Cosmic Ray Particles

    ERIC Educational Resources Information Center

    Gron, Oyvind

    2010-01-01

    Two important questions concerning cosmic rays are: Why are electrons in the cosmic rays less efficiently accelerated than nuclei? How are particles accelerated to great energies in ultra-high energy cosmic rays? In order to answer these questions we construct a simple model of the acceleration of a charged particle in the cosmic ray. It is not…

  5. Relativistic transport theory for cosmic-rays

    NASA Technical Reports Server (NTRS)

    Webb, G. M.

    1985-01-01

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

  6. Cosmic ray antimatter and baryon symmetric cosmology

    NASA Technical Reports Server (NTRS)

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

    1982-01-01

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

  7. ULTRA-HIGH-ENERGY Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Westerhoff, Stefan

    2006-01-01

    One of the most striking astrophysical phenomena today is the existence of cosmic ray particles with energies in excess of 1020 eV. While their presence has been confirmed by a number of experiments, it is not clear where and how these particles are accelerated to these energies and how they travel astronomical distances without substantial energy loss. We are entering an exciting new era in cosmic ray physics, with instruments now producing data of unprecedented quality and quantity to tackle the many open questions. This paper reviews the current experimental status of cosmic ray physics and summarizes recent results on the energy spectrum and arrival directions of ultra-high-energy cosmic rays.

  8. Temporal Variation in Cosmic Ray Muon Flux

    NASA Astrophysics Data System (ADS)

    Stroberg, Steven; Evans, Kalya; Lyles-Goldblum, Bethany; Swanberg, Erik; Norman, Eric

    2008-10-01

    Plastic scintillator detectors are often used in homeland security applications that look for high energy photons, such as active interrogation of cargo containers. In these applications, the background due to cosmic ray muons is assumed to be constant. However, there appears to be potentially significant variation in the muon flux over time. The muon flux was measured over a period of several months using two plastic scintillator detectors (122x61x15 cm and 30x30x10 cm). The data from these detectors were compared to data from cosmic ray neutron detectors in Kiel, Calgary, Moscow, Thule and Beijing collected during the same time period. The response function of the two detectors was also compared with a model developed in MCNPX code using the CRY simulated cosmic ray background. Preliminary data suggest that the temporal variation in muons is significantly greater than that of the cosmic ray neutrons.

  9. Cosmic ray transport near the heliopause

    NASA Astrophysics Data System (ADS)

    Strauss, R. D.; Fichtner, H.; Potgieter, M. S.; le Roux, J. A.; Luo, X.

    2015-09-01

    In this paper we summarize our modelling efforts for cosmic rays near the heliopause, and discuss whether galactic cosmic ray modulation beyond the heliopause is possible and present an explanation for the anisotropic nature of the observed cosmic ray intensities in the very local interstellar medium. We show that (i) modulation beyond the heliopause is possible, but highly dependent on the assumed parameters (most notable, the perpendicular diffusion coefficient). Treating the heliopause as a tangential discontinuity, significantly damps this modulation effect and leads to modelled results that are similar to Voyager 1 observations. (ii) By choosing an appropriate functional form of the perpendicular diffusion coefficient on the pitch-angle level, we are able to account for the anisotropic behaviour observed for both galactic and anomalous cosmic rays in the local interstellar medium.

  10. COSMIC-RAY HELIUM HARDENING

    SciTech Connect

    Ohira, Yutaka; Ioka, Kunihito

    2011-03-01

    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.

  11. Apollo 17 lunar surface cosmic ray detector

    NASA Technical Reports Server (NTRS)

    Walker, R. M.

    1974-01-01

    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.

  12. Chaotic Properties of High Energy Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Ticona, A.; Ticona, R.; Martinic, N.; Poma, I.; Gutierrez, R.; Calle, R.; Rodriguez, E.

    2006-04-01

    Using the dimension of correlation analysis, we study the time series intervals of the high-energy cosmic ray data, obtained in the mount of Chacaltaya, in the experiment S.Y.S. Some of the analyzed groups present a fractal dimension close to 3. This fractal dimension seems to show that the transport system of cosmic ray would be chaotic under some circumstances. Results show that only data of charged particles present this fractal property.

  13. The Lateral Trigger Probability function for the ultra-high energy cosmic ray showers detected by the Pierre Auger Observatory

    SciTech Connect

    Abreu, P.; Aglietta, M.; Ahn, E.J.; Albuquerque, I.F.M.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Alvarez Castillo, J.; Alvarez-Muniz, J.; Ambrosio, M.; /INFN, Naples /Naples U. /Nijmegen U., IMAPP

    2011-01-01

    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{sup 17} and 10{sup 19} eV and zenith angles up to 65{sup o}. 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.

  14. Autocorrelation Analysis Combined with a Wavelet Transform Method to Detect and Remove Cosmic Rays in a Single Raman Spectrum.

    PubMed

    Maury, Augusto; Revilla, Reynier I

    2015-08-01

    Cosmic rays (CRs) occasionally affect charge-coupled device (CCD) detectors, introducing large spikes with very narrow bandwidth in the spectrum. These CR features can distort the chemical information expressed by the spectra. Consequently, we propose here an algorithm to identify and remove significant spikes in a single Raman spectrum. An autocorrelation analysis is first carried out to accentuate the CRs feature as outliers. Subsequently, with an adequate selection of the threshold, a discrete wavelet transform filter is used to identify CR spikes. Identified data points are then replaced by interpolated values using the weighted-average interpolation technique. This approach only modifies the data in a close vicinity of the CRs. Additionally, robust wavelet transform parameters are proposed (a desirable property for automation) after optimizing them with the application of the method in a great number of spectra. However, this algorithm, as well as all the single-spectrum analysis procedures, is limited to the cases in which CRs have much narrower bandwidth than the Raman bands. This might not be the case when low-resolution Raman instruments are used. PMID:26163458

  15. Cosmic ray acceleration in young supernova remnants

    NASA Astrophysics Data System (ADS)

    Schure, K. M.; Bell, A. R.

    2013-10-01

    We investigate the appearance of magnetic field amplification resulting from a cosmic ray escape current in the context of supernova remnant shock waves. The current is inversely proportional to the maximum energy of cosmic rays, and is a strong function of the shock velocity. Depending on the evolution of the shock wave, which is drastically different for different circumstellar environments, the maximum energy of cosmic rays as required to generate enough current to trigger the non-resonant hybrid instability that confines the cosmic rays follows a different evolution and reaches different values. We find that the best candidates to accelerate cosmic rays to few PeV energies are young remnants in a dense environment, such as a red supergiant wind, as may be applicable to Cassiopeia A. We also find that for a typical background magnetic field strength of 5 ?G the instability is quenched in about 1000 years, making SN1006 just at the border of candidates for cosmic ray acceleration to high energies.

  16. Cosmic ray produced isotopes in terrestrial systems.

    NASA Astrophysics Data System (ADS)

    Lal, D.

    1998-12-01

    Continuing improvements in the sensitivity of measurement of cosmic ray produced isotopes in environmental samples have progressively broadened the scope of their applications to characterise and quantify a wide variety of processes in Earth and planetary sciences. In this article, the author concentrates on the new developments in the field of nuclear geophysics, based on isotopic changes produced by cosmic rays in the terrestrial systems. This field, which is best described as cosmic ray geophysics, has roots with the discovery of cosmogenic 14C on the Earth by Willard Libby in 1948, and grew rapidly at first, but slowed down during the '60s and '70s. In the '80s, there was a renaissance in cosmic ray produced isotope studies, thanks mainly to the developments of the accelerator mass spectrometry technique capable of measuring minute amounts of radioactivity in terrestrial samples. This technological advance has considerably enhanced the applications of cosmic ray produced isotopes and today one finds them being used to address diverse problems in Earth and planetary sciences. The author discusses the present scope of the field of cosmic ray geophysics with an emphasis on geomorphology. It is stressed that this is the decade in which this field, which has been studied passionately by geographers, geomorphologists and geochemists for more than five decades, has at its service nuclear methods to introduce numeric time controls in the range of centuries to millions of years.

  17. Reminiscences of cosmic ray research in Mexico

    NASA Astrophysics Data System (ADS)

    Pérez-Peraza, Jorge

    2009-11-01

    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 Mérida, 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.

  18. Gamma-rays from cosmic ray interactions in supernova shells

    NASA Technical Reports Server (NTRS)

    Harding, A. K.; Mastichiadis, A.; Protheroe, R. J.; Szabo, A. P.

    1991-01-01

    A model is presented for the transport and interaction of cosmic rays accelerated by a pulsar and confined inside an expanding supernova remnant. Assuming that protons are accelerated at the reverse shock in the confined pulsar wind and convected into the shell via the Rayleigh-Taylor instability, the diffusion and interaction of these protons in the expanding envelope is modeled. The resulting gamma-ray flux is lower than previous estimates due primarily to the inclusion of proton adiabatic losses in the expanding pulsar wind. Energy-dependent diffusion causes the higher energy gamma-ray light curves to decay faster than those at lower energy. The predicted flux from SN1987A, for proton luminosity less than 10 exp 40 erg/s, is below the present detector sensitivities at both GeV and TeV energies, although supernovae occurring within the Galaxy may be detectable.

  19. Spiral arms as cosmic ray source distributions

    NASA Astrophysics Data System (ADS)

    Werner, M.; Kissmann, R.; Strong, A. W.; Reimer, O.

    2015-04-01

    The Milky Way is a spiral galaxy with (or without) a bar-like central structure. There is evidence that the distribution of suspected cosmic ray sources, such as supernova remnants, are associated with the spiral arm structure of galaxies. It is yet not clearly understood what effect such a cosmic ray source distribution has on the particle transport in our Galaxy. We investigate and measure how the propagation of Galactic cosmic rays is affected by a cosmic ray source distribution associated with spiral arm structures. We use the PICARD code to perform high-resolution 3D simulations of electrons and protons in galactic propagation scenarios that include four-arm and two-arm logarithmic spiral cosmic ray source distributions with and without a central bar structure as well as the spiral arm configuration of the NE2001 model for the distribution of free electrons in the Milky Way. Results of these simulation are compared to an axisymmetric radial source distribution. Also, effects on the cosmic ray flux and spectra due to different positions of the Earth relative to the spiral structure are studied. We find that high energy electrons are strongly confined to their sources and the obtained spectra largely depend on the Earth's position relative to the spiral arms. Similar finding have been obtained for low energy protons and electrons albeit at smaller magnitude. We find that even fractional contributions of a spiral arm component to the total cosmic ray source distribution influences the spectra on the Earth. This is apparent when compared to an axisymmetric radial source distribution as well as with respect to the Earth's position relative to the spiral arm structure. We demonstrate that the presence of a Galactic bar manifests itself as an overall excess of low energy electrons at the Earth. Using a spiral arm geometry as a cosmic ray source distributions offers a genuine new quality of modeling and is used to explain features in cosmic ray spectra at the Earth that are else-wise attributed to other propagation effects. We show that realistic cosmic ray propagation scenarios have to acknowledge non-axisymmetric source distributions.

  20. Contributions to the 19th International Cosmic Ray Conference

    NASA Technical Reports Server (NTRS)

    1985-01-01

    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.

  1. CTA and cosmic-ray diffusion in molecular clouds

    NASA Astrophysics Data System (ADS)

    Pedaletti, G.; Torres, D. F.; Gabici, S.; de Oa Wilhelmi, E.; Mazin, D.; Stamatescu, V.

    2012-12-01

    Molecular clouds act as primary targets for cosmic-ray interactions and are expected to shine in gamma-rays as a by-product of these interactions. Indeed several detected gamma-ray sources both in HE and VHE gamma-rays (HE: 100 MeV < E < 100 GeV; VHE: E > 100 GeV) have been directly or indirectly associated with molecular clouds. Information on the local diffusion coefficient and the local cosmic-ray population can be deduced from the observed gamma-ray signals. In this work we concentrate on the capability of the forthcoming Cherenkov Telescope Array Observatory (CTA) to provide such measurements. We investigate the expected emission from clouds hosting an accelerator, exploring the parameter space for different modes of acceleration, age of the source, cloud density profile, and cosmic ray diffusion coefficient. We present some of the most interesting cases for CTA regarding this science topic. The simulated gamma-ray fluxes depend strongly on the input parameters. In some cases, from CTA data it will be possible to constrain both the properties of the accelerator and the propagation mode of cosmic rays in the cloud.

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

    SciTech Connect

    Cowsik, R.; Burch, B.

    2010-07-15

    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.

  3. Large scale distribution of ultra high energy cosmic rays detected at the Pierre Auger Observatory with zenith angles up to 80

    SciTech Connect

    Aab, Alexander

    2015-03-30

    In this study, we present the results of an analysis of the large angular scale distribution of the arrival directions of cosmic rays with energy above 4 EeV detected at the Pierre Auger Observatory including for the first time events with zenith angle between 60 and 80. We perform two Rayleigh analyses, one in the right ascension and one in the azimuth angle distributions, that are sensitive to modulations in right ascension and declination, respectively. The largest departure from isotropy appears in the $E\\gt 8$ EeV energy bin, with an amplitude for the first harmonic in right ascension $r_{1}^{\\alpha }=(4.4\\pm 1.0)\\times {{10}^{-2}}$, that has a chance probability $P(\\geqslant r_{1}^{\\alpha })=6.4\\times {{10}^{-5}}$, reinforcing the hint previously reported with vertical events alone.

  4. Large scale distribution of ultra high energy cosmic rays detected at the Pierre Auger Observatory with zenith angles up to 80°

    DOE PAGESBeta

    Aab, Alexander

    2015-03-30

    In this study, we present the results of an analysis of the large angular scale distribution of the arrival directions of cosmic rays with energy above 4 EeV detected at the Pierre Auger Observatory including for the first time events with zenith angle between 60° and 80°. We perform two Rayleigh analyses, one in the right ascension and one in the azimuth angle distributions, that are sensitive to modulations in right ascension and declination, respectively. The largest departure from isotropy appears in themore » $$E\\gt 8$$ EeV energy bin, with an amplitude for the first harmonic in right ascension $$r_{1}^{\\alpha }=(4.4\\pm 1.0)\\times {{10}^{-2}}$$, that has a chance probability $$P(\\geqslant r_{1}^{\\alpha })=6.4\\times {{10}^{-5}}$$, reinforcing the hint previously reported with vertical events alone.« less

  5. Large Scale Distribution of Ultra High Energy Cosmic Rays Detected at the Pierre Auger Observatory with Zenith Angles up to 80°

    NASA Astrophysics Data System (ADS)

    Aab, A.; Abreu, P.; Aglietta, M.; Ahn, E. J.; Samarai, I. Al; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Aramo, C.; Aranda, V. M.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Awal, N.; Badescu, A. M.; Barber, K. B.; Bäuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertaina, M. E.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blaess, S. G.; Blanco, M.; Bleve, C.; Blümer, H.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Bridgeman, A.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Buitink, S.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Candusso, M.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Chavez, A. G.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Coleman, A.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cooper, M. J.; Cordier, A.; Coutu, S.; Covault, C. E.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; de Jong, S. J.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Di Matteo, A.; Diaz, J. C.; Díaz Castro, M. L.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dorofeev, A.; Dorosti Hasankiadeh, Q.; Dova, M. T.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fernandes, M.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipčič, A.; Fox, B. D.; Fratu, O.; Freire, M. M.; Fröhlich, U.; Fuchs, B.; Fujii, T.; Gaior, R.; García, B.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gate, F.; Gemmeke, H.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Glaser, C.; Glass, H.; Gómez Berisso, M.; Gómez Vitale, P. F.; Gonçalves, P.; Gonzalez, J. G.; González, N.; Gookin, B.; Gordon, J.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guarino, F.; Guedes, G. P.; Hampel, M. R.; Hansen, P.; Harari, D.; Harrison, T. A.; Hartmann, S.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huber, D.; Huege, T.; Insolia, A.; Isar, P. G.; Jandt, I.; Jansen, S.; Jarne, C.; Josebachuili, M.; Kääpä, A.; Kambeitz, O.; Kampert, K. H.; Kasper, P.; Katkov, I.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kunka, N.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Malacari, M.; Maldera, S.; Mallamaci, M.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Mariş, I. C.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martínez Bravo, O.; Martraire, D.; Masías Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Meissner, R.; Melissas, M.; Melo, D.; Menshikov, A.; Messina, S.; Meyhandan, R.; Mićanović, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morello, C.; Mostafá, M.; Moura, C. A.; Muller, M. A.; Müller, G.; Müller, S.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nguyen, P. H.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nožka, L.; Ochilo, L.; Oikonomou, F.; Olinto, A.; Oliveira, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Papenbreer, P.; Parente, G.; Parra, A.; Paul, T.; Pech, M.; Pȩkala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Petermann, E.; Peters, C.; Petrera, S.; Petrov, Y.; Phuntsok, J.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porcelli, A.; Porowski, C.; Prado, R. R.; Privitera, P.; Prouza, M.; Purrello, V.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rizi, V.; Rodrigues de Carvalho, W.; Rodriguez Fernandez, G.; Rodriguez Rojo, J.; Rodríguez-Frías, M. D.; Rogozin, D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Roulet, E.; Rovero, A. C.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Saleh, A.; Salesa Greus, F.; Salina, G.; Sánchez, F.; Sanchez-Lucas, P.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarmento, R.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, D.; Scholten, O.; Schoorlemmer, H.; Schovánek, P.; Schröder, F. G.; Schulz, A.; Schulz, J.; Schumacher, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Sima, O.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Squartini, R.; Srivastava, Y. N.; Stanič, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Taborda, O. A.; Tapia, A.; Tepe, A.; Theodoro, V. M.; Timmermans, C.; Todero Peixoto, C. J.; Toma, G.; Tomankova, L.; Tomé, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Travnicek, P.; Trovato, E.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van Bodegom, P.; van den Berg, A. M.; van Velzen, S.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Varner, G.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Vicha, J.; Videla, M.; Villaseñor, L.; Vlcek, B.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Widom, A.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Williams, C.; Winchen, T.; Wittkowski, D.; Wundheiler, B.; Wykes, S.; Yamamoto, T.; Yapici, T.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.; Zuccarello, F.

    2015-04-01

    We present the results of an analysis of the large angular scale distribution of the arrival directions of cosmic rays with energy above 4 EeV detected at the Pierre Auger Observatory including for the first time events with zenith angle between 60° and 80°. We perform two Rayleigh analyses, one in the right ascension and one in the azimuth angle distributions, that are sensitive to modulations in right ascension and declination, respectively. The largest departure from isotropy appears in the E\\gt 8 EeV energy bin, with an amplitude for the first harmonic in right ascension r1α =(4.4+/- 1.0)× {{10}-2}, that has a chance probability P(≥slant r1α )=6.4× {{10}-5}, reinforcing the hint previously reported with vertical events alone.

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

    NASA Astrophysics Data System (ADS)

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

    2011-06-01

    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.

  7. Large scale distribution of ultra high energy cosmic rays detected at the Pierre Auger Observatory with zenith angles up to 80°

    SciTech Connect

    Aab, Alexander

    2015-03-30

    In this study, we present the results of an analysis of the large angular scale distribution of the arrival directions of cosmic rays with energy above 4 EeV detected at the Pierre Auger Observatory including for the first time events with zenith angle between 60° and 80°. We perform two Rayleigh analyses, one in the right ascension and one in the azimuth angle distributions, that are sensitive to modulations in right ascension and declination, respectively. The largest departure from isotropy appears in the $E\\gt 8$ EeV energy bin, with an amplitude for the first harmonic in right ascension $r_{1}^{\\alpha }=(4.4\\pm 1.0)\\times {{10}^{-2}}$, that has a chance probability $P(\\geqslant r_{1}^{\\alpha })=6.4\\times {{10}^{-5}}$, reinforcing the hint previously reported with vertical events alone.

  8. Measurement of the cosmic ray spectrum above 4×1018 eV using inclined events detected with the Pierre Auger Observatory

    DOE PAGESBeta

    Aab, Alexander

    2015-08-26

    A measurement of the cosmic-ray spectrum for energies exceeding 4×1018 eV is presented, which is based on the analysis of showers with zenith angles greater than 60° detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above 5.3×1018 eV, the ``ankle'', the flux can be described by a power law E–γ with index γ=2.70 ± 0.02 (stat) ± 0.1 (sys) followed by a smooth suppression region. For the energy (Es) at which the spectral flux has fallen to one-half of its extrapolated value inmore » the absence of suppression, we find Es=(5.12±0.25 (stat)+1.0–1.2 (sys))×1019 eV.« less

  9. Gev-Tev Galactic Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Lavalle, Julien

    2015-03-01

    This short review aims at presenting the way we currently understand, model, and constrain the transport of cosmic rays in the GeV-TeV energy domain. This is a research field per se, but is also an important tool e.g. to improve our understanding of the cosmic-ray sources, of the diffuse non-thermal Galactic emissions (from radio wavelengths to gamma-rays), or in searches for dark matter annihilation signals. This review is mostly dedicated to particle physicists or more generally to non-experts.

  10. Cosmic ray propagation in interstellar space

    NASA Astrophysics Data System (ADS)

    Farahat, Ashraf Mohamed Samir

    2005-06-01

    The astrophysics of cosmic rays is a very broad field of research, concerned with questions like where and how cosmic rays are accelerated, how they propagate and interact with the interstellar medium. In recent years a huge number of studies have been devoted to cosmic rays and to questions related to them as new and accurate observational data become available. Many models have been developed and have succeeded in reproducing observational data of many kinds related to cosmic rays using realistic astrophysical parameters; however many problems can't be addressed using these models such as inhomogeneities and small scale structure in the interstellar space. With this incentive we developed a new numerical model to describe the cosmic rays interactions and propagation in the galaxy and to handle many limitations of previously developed models. Our model depends on using the time backward Markov Stochastic solution of the general diffusion transport equation developed by Zhang [1999]; however we extend the solution to solve a group of diffusion transport equations, each representing a particular element or isotope in the cosmic ray nuclei. The new technique fits the observational data for several elemental and isotopic abundance ratios over a wide energy range. The new method is not only helpful in addressing the effects of the low and high density regions in the interstellar space on the elemental and isotopic ratio but also on the determination of the contribution of individual nuclei and galactic locations to the production of certain cosmic ray nuclei. The Markov Stochastic method was also used to calculate cosmic rays propagation within a halo diffusion model. The energy dependent path-length probability distribution (PLD) is combined with a weighted slab model to determine the production of secondary cosmic ray nuclei. This combination allows the seamless incorporation of the low density Local Bubble surrounding the solar system. While the effect of the Local Bubble on the primary to secondary abundance ratios of stable nuclei is minimal, the effect on unstable short lived isotopes is significant. This study also pointed out that many modulation models describe the modulation level using a single number called the modulation parameter; however using the same modulation parameter with different selected models doesn't usually result in the same level modulation. This means that the modulation parameter is a model.

  11. Cosmic Ray Nuclei (CRN) detector investigation

    NASA Technical Reports Server (NTRS)

    Meyer, Peter; Muller, Dietrich; Lheureux, Jacques; Swordy, Simon

    1991-01-01

    The Cosmic Ray Nuclei (CRN) detector was designed to measure elemental composition and energy spectra of cosmic radiation nuclei ranging from lithium to iron. CRN was flown as part of Spacelab 2 in 1985, and consisted of three basic components: a gas Cerenkov counter, a transition radiation detector, and plastic scintillators. The results of the experiment indicate that the relative abundance of elements in this range, traveling at near relativistic velocities, is similar to those reported at lower energy.

  12. THE INTERACTION OF COSMIC RAYS WITH DIFFUSE CLOUDS

    SciTech Connect

    Everett, John E.; Zweibel, Ellen G.

    2011-10-01

    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}).

  13. Cosmic Ray Interactions in Shielding Materials

    SciTech Connect

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

    2011-09-08

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

  14. Ultra heavy cosmic ray experiment (A0178)

    NASA Technical Reports Server (NTRS)

    Thompson, A.; Osullivan, D.; Bosch, J.; Keegan, R.; Wenzel, K. P.; Jansen, F.; Domingo, C.

    1992-01-01

    The Ultra Heavy Cosmic Ray Experiment (UHCRE) is based on a modular array of 192 side viewing solid state nuclear track detector stacks. These stacks were mounted in sets of four in 48 pressure vessels using 16 peripheral LDEF trays. The geometry factor for high energy cosmic ray nuclei, allowing for Earth shadowing, was 30 sq m sr, giving a total exposure factor of 170 sq m sr y at an orbital inclination of 28.4 degs. Scanning results indicate that about 3000 cosmic ray nuclei in the charge region with Z greater than 65 were collected. This sample is more than ten times the current world data in the field (taken to be the data set from the HEAO-3 mission plus that from the Ariel-6 mission) and is sufficient to provide the world's first statistically significant sample of actinide cosmic rays. Results are presented including a sample of ultra heavy cosmic ray nuclei, analysis of pre-flight and post-flight calibration events and details of track response in the context of detector temperature history. The integrated effect of all temperature and age related latent track variations cause a maximum charge shift of + or - 0.8e for uranium and + or - 0.6e for the platinum-lead group. Astrophysical implications of the UHCRE charge spectrum are discussed.

  15. Supernova Remnants, Cosmic Rays, and GLAST

    SciTech Connect

    Reynolds, Steve

    2006-02-13

    The shock waves of supernova remnants (SNRs) are the traditional sources of Galactic cosmic rays, at least up to about 3000 TeV (the 'knee' energy in the cosmic-ray spectrum). In the last decade or so, X-ray observations have confirmed in a few SNRs the presence of synchrotron-X-ray-emitting electrons with energies of order 100 TeV. TeV photons from SNRs have been observed with ground-based air Cerenkov telescopes as well, but it is still unclear whether they are due to hadronic processes (inelastic p-p scattering of cosmic-ray protons from thermal gas, with secondary neutral pions decaying to gamma rays), or to leptonic processes (inverse-Compton upscattering of cosmic microwave background photons, or bremsstrahlung). The spatial structure of synchrotron X-rays as observed with the Chandra X-ray Observatory suggests the remarkable possibility that magnetic fields are amplified by orders of magnitude in strong shock waves. The electron spectra inferred from X-rays reach 100 TeV, but at that energy are cutting off steeply, well below the 'knee' energy. Are the cutoff processes due only to radiative losses so that ion spectra might continue unsteepened? Can we confirm the presence of energetic ions in SNRs at all? Are typical SNRs capable of supplying the pool of Galactic cosmic rays? Is strong magnetic-field amplification a property of strong astrophysical shocks in general? These major questions require the next generation of observational tools. I shall outline the theoretical and observational framework of particle acceleration to high energies in SNRs, and shall describe how GLAST will advance this field.

  16. Supernova Remnants, Cosmic Rays, and GLAST

    SciTech Connect

    Reynolds, Steve

    2006-02-13

    The shock waves of supernova remnants (SNRs) are the traditional sources of Galactic cosmic rays, at least up to about 3000 TeV (the "knee" energy in the cosmic-ray spectrum). In the last decade or so, X-ray observations have confirmed in a few SNRs the presence of synchrotron-X-ray-emitting electrons with energies of order 100 TeV. TeV photons from SNRs have been observed with ground-based air Cerenkov telescopes as well, but it is still unclear whether they are due to hadronic processes (inelastic p-p scattering of cosmic-ray protons from thermal gas, with secondary neutral pions decaying to gamma rays), or to leptonic processes (inverse-Compton upscattering of cosmic microwave background photons, or bremsstrahlung). The spatial structure of synchrotron X-rays as observed with the Chandra X-ray Observatory suggests the remarkable possibility that magnetic fields are amplified by orders of magnitude in strong shock waves. The electron spectra inferred from X-rays reach 100 TeV, but at that energy are cutting off steeply, well below the "knee" energy. Are the cutoff processes due only to radiative losses so that ion spectra might continue unsteepened? Can we confirm the presence of energetic ions in SNRs at all? Are typical SNRs capable of supplying the pool of Galactic cosmic rays? Is strong magnetic-field amplification a property of strong astrophysical shocks in general? These major questions require the next generation of observational tools. I shall outline the theoretical and observational framework of particle acceleration to high energies in SNRs, and shall describe how GLAST will advance this field.

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

    NASA Technical Reports Server (NTRS)

    Moiseev, Alexander

    2011-01-01

    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,

  18. COSMIC RAY BACKGROUND ANALYSIS FOR A CARGO CONTAINER COUNTER.

    SciTech Connect

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

    2001-01-01

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

  19. Cosmic ray sun shadow in Soudan 2 underground muon flux.

    SciTech Connect

    Allison, W. W. M.; Alner, G. J.; Ayres, D. S.; Barrett, W. L.; Bode, C.; Fields, T. H.; Goodman, M. C.; Joffe-Minor, T.; Price, L. E.; Seidlein, R.; Soudan 2 Collaboration; Thron, J. L.

    1999-06-23

    The absorption of cosmic rays by the sun produces a shadow at the earth. The angular offset and broadening of the shadow are determined by the magnitude and structure of the interplanetary magnetic field (IPMF) in the inner solar system. The authors report the first measurement of the solar cosmic ray shadow by detection of deep underground muon flux in observations made during the entire ten-year interval 1989 to 1998. The sun shadow varies significantly during this time, with a 3.3{sigma} shadow observed during the years 1995 to 1998.

  20. Searching for ultra-high energy cosmic rays with smartphones

    NASA Astrophysics Data System (ADS)

    Whiteson, Daniel; Mulhearn, Michael; Shimmin, Chase; Cranmer, Kyle; Brodie, Kyle; Burns, Dustin

    2016-06-01

    We propose a novel approach for observing cosmic rays at ultra-high energy (>1018 eV) by repurposing the existing network of smartphones as a ground detector array. Extensive air showers generated by cosmic rays produce muons and high-energy photons, which can be detected by the CMOS sensors of smartphone cameras. The small size and low efficiency of each sensor is compensated by the large number of active phones. We show that if user adoption targets are met, such a network will have significant observing power at the highest energies.

  1. Gamma ray bursts and extreme energy cosmic rays

    SciTech Connect

    Scarsi, Livio

    1998-06-15

    Extreme Energy Cosmic Ray particles (EECR) with E>10{sup 20} eV arriving on Earth with very low flux ({approx}1 particle/Km{sup 2}-1000yr) require for their investigation very large detecting areas, exceeding values of 1000 km{sup 2} sr. Projects with these dimensions are now being proposed: Ground Arrays ('Auger' with 2x3500 km{sup 2} sr) or exploiting the Earth Atmosphere as seen from space ('AIR WATCH' and OWL,'' with effective area reaching 1 million km{sup 2} sr). In this last case, by using as a target the 10{sup 13} tons of air viewed, also the high energy neutrino flux can be investigated conveniently. Gamma Rays Bursts are suggested as a possible source for EECR and the associated High Energy neutrino flux.

  2. Nineteenth International Cosmic Ray Conference. HE Sessions, Volume 8

    NASA Technical Reports Server (NTRS)

    Jones, F. C. (Compiler)

    1985-01-01

    Papers submitted for presentation at the 19th International Cosmic Ray Conference are compiled. The present volume contains papers addressing high energy interactions and related phenomena. Specific topic areas include muons, neutrinos, magnetic monopoles, nucleon decay, searches for new particles, and acoustic and thermoluminescence detection techniques.

  3. Precision measurement of cosmic-Ray antiproton spectrum

    PubMed

    Orito; Maeno; Matsunaga; Abe; Anraku; Asaoka; Fujikawa; Imori; Ishino; Makida; Matsui; Matsumoto; Mitchell; Mitsui; Moiseev; Motoki; Nishimura; Nozaki; Ormes; Saeki; Sanuki; Sasaki; Seo; Shikaze; Sonoda; Streitmatter

    2000-02-01

    The energy spectrum of cosmic-ray antiprotons ( &pmacr;'s) has been measured in the range 0.18-3.56 GeV, based on 458 &pmacr;'s collected by BESS in a recent solar-minimum period. We have detected for the first time a characteristic peak at 2 GeV of &pmacr;'s originating from cosmic-ray interactions with the interstellar gas. The peak spectrum is reproduced by theoretical calculations, implying that the propagation models are basically correct and that different cosmic-ray species undergo a universal propagation. Future BESS data with still higher statistics will allow us to study the solar modulation and the propagation in detail and to search for primary &pmacr; components. PMID:11017448

  4. Cosmogenic neutrinos and ultra-high energy cosmic ray models

    NASA Astrophysics Data System (ADS)

    Aloisio, R.; Boncioli, D.; di Matteo, A.; Grillo, A. F.; Petrera, S.; Salamida, F.

    2015-10-01

    We use an updated version of SimProp, a Monte Carlo simulation scheme for the propagation of ultra-high energy cosmic rays, to compute cosmogenic neutrino fluxes expected on Earth in various scenarios. These fluxes are compared with the newly detected IceCube events at PeV energies and with recent experimental limits at EeV energies of the Pierre Auger Observatory. This comparison allows us to draw some interesting conclusions about the source models for ultra-high energy cosmic rays. We will show how the available experimental observations are almost at the level of constraining such models, mainly in terms of the injected chemical composition and cosmological evolution of sources. The results presented here will also be important in the evaluation of the discovery capabilities of the future planned ultra-high energy cosmic ray and neutrino observatories.

  5. Integral Neutron Multiplicity Measurements from Cosmic Ray Interactions in Lead

    SciTech Connect

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

    2006-07-11

    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)

  6. One century of cosmic rays - A particle physicist's view

    NASA Astrophysics Data System (ADS)

    Sutton, Christine

    2015-12-01

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

  7. Cosmic Ray-Air Shower Measurement from Space

    NASA Technical Reports Server (NTRS)

    Takahashi, Yoshiyuki

    1997-01-01

    A feasibility study has been initiated to observe from space the highest energy cosmic rays above 1021 eV. A satellite observatory concept, the Maximum-energy Auger (Air)-Shower Satellite (MASS), is recently renamed as the Orbital Wide-angle Collector (OWL) by taking its unique feature of using a very wide field-of-view (FOV) optics. A huge array of imaging devices (about 10(exp 6) pixels) is required to detect and record fluorescent light profiles of cosmic ray cascades in the atmosphere. The FOV of MASS could extend to as large as about 60 in. diameter, which views (500 - 1000 km) of earth's surface and more than 300 - 1000 cosmic ray events per year could be observed above 1020 eV. From far above the atmosphere, the MASS/OWL satellite should be capable of observing events at all angles including near horizontal tracks, and would have considerable aperture for high energy photon and neutrino observation. With a large aperture and the spatial and temporal resolution, MASS could determine the energy spectrum, the mass composition, and arrival anisotropy of cosmic rays from 1020 eV to 1022 eV; a region hitherto not explored by ground-based detectors such as the Fly's Eye and air-shower arrays. MASS/OWL's ability to identify cosmic neutrinos and gamma rays may help providing evidence for the theory which attributes the above cut-off cosmic ray flux to the decay of topological defects. Very wide FOV optics system of MASS/OWL with a large array of imaging devices is applicable to observe other atmospheric phenomena including upper atmospheric lightning. The wide FOV MASS optics being developed can also improve ground-based gamma-ray observatories by allowing simultaneous observation of many gamma ray sources located at different constellations.

  8. Does electromagnetic radiation accelerate galactic cosmic rays

    NASA Technical Reports Server (NTRS)

    Eichler, D.

    1977-01-01

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

  9. He-3 in galactic cosmic rays

    NASA Astrophysics Data System (ADS)

    Mewaldt, R. A.

    1986-12-01

    Cosmic-ray 3He/4He observations, including a new measurement at ≡65 MeV per nucleon from ISEE 3, are compared with interstellar propagation and solar modulation calculations in an effort to understand the origin of cosmic-ray He nuclei. The author surveys spacecraft and balloon observations of the 3He/4He ratio and finds improved consistency among measurements in the ≡50 - 300 MeV per nucleon energy range when a previously neglected contribution from atmospheric secondary 3He is taken into account. These low-energy observations imply a mean escape length of 6 - 8 g cm-2 in the standard "leaky box" model for cosmic-ray propagation in the galaxy. The data show no evidence for an excess of low-energy 3He such as that reported at higher energies.

  10. Anomalous isotopic composition of cosmic rays

    SciTech Connect

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

    1980-06-20

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

  11. PARSEC: PARametrized Simulation Engine for Cosmic rays

    NASA Astrophysics Data System (ADS)

    Bretz, Hans-Peter; Erdmann, Martin; Schiffer, Peter; Walz, David; Winchen, Tobias

    2015-02-01

    PARSEC (PARametrized Simulation Engine for Cosmic rays) is a simulation engine for fast generation of ultra-high energy cosmic ray data based on parameterizations of common assumptions of UHECR origin and propagation. Implemented are deflections in unstructured turbulent extragalactic fields, energy losses for protons due to photo-pion production and electron-pair production, as well as effects from the expansion of the universe. Additionally, a simple model to estimate propagation effects from iron nuclei is included. Deflections in the Galactic magnetic field are included using a matrix approach with precalculated lenses generated from backtracked cosmic rays. The PARSEC program is based on object oriented programming paradigms enabling users to extend the implemented models and is steerable with a graphical user interface.

  12. He-3 in galactic cosmic rays

    SciTech Connect

    Mewaldt, R.A.

    1986-12-01

    Cosmic-ray He-3/He-4 observations, including a new measurement around 65 MeV per nucleon from ISEE-3, are compared with interstellar propagation and solar modulation calculations in an effort to understand the origin of cosmic-ray He nuclei. A survey of spacecraft and balloon observations of the He-3/He-4 ratio shows improved consistency among measurements in the 50-300 MeV per nucleon energy range when a previously neglected contribution from atmospheric secondary He-3 is taken into account. These low-energy observations imply a mean escape length of 6-8 g/sq cm in the standard leaky box model for cosmic-ray propagation in the Galaxy, a value consistent with that derived from studies of heavier nuclei. No evidence is found for an excess of low-energy He-3 such as that reported at high energies. 42 references.

  13. Cosmic-ray streaming and anisotropies

    NASA Technical Reports Server (NTRS)

    Forman, M. A.; Gleeson, L. J.

    1975-01-01

    The paper is concerned with the differential current densities and anisotropies that exist in the interplanetary cosmic-ray gas, and in particular with a correct formulation and simple interpretation of the momentum equation that describes these on a local basis. Two examples of the use of this equation in the interpretation of previous data are given. It is demonstrated that in interplanetary space, the electric-field drifts and convective flow parallel to the magnetic field of cosmic-ray particles combine as a simple convective flow with the solar wind, and that there exist diffusive currents and transverse gradient drift currents. Thus direct reference to the interplanetary electric-field drifts is eliminated, and the study of steady-state and transient cosmic-ray anisotropies is both more systematic and simpler.

  14. The HEAO-3 Cosmic Ray Isotope spectrometer

    NASA Technical Reports Server (NTRS)

    Bouffard, M.; Engelmann, J. J.; Koch, L.; Soutoul, A.; Lund, N.; Peters, B.; Rasmussen, I. L.

    1982-01-01

    This paper describes the Cosmic Ray Isotope instrument launched aboard the HEAO-3 satellite on September 20, 1979. The primary purpose of the experiment is to measure the isotopic composition of cosmic ray nuclei from Be-7 to Fe-58 over the energy range 0.5 to 7 GeV/nucleon. In addition charge spectra will be measured between beryllium and tin over the energy range 0.5 to 25 GeV/nucleon. The charge and isotope abundances measured by the experiment provide essential information needed to further our understanding of the origin and propagation of high energy cosmic rays. The instrument consists of 5 Cerenkov counters, a 4 element neon flash tube hodoscope and a time-of-flight system. The determination of charge and energy for each particle is based on the multiple Cerenkov technique and the mass determination will be based upon a statistical analysis of particle trajectories in the geomagnetic field.

  15. Positron Abundance in Galactic Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Clem, John M.; Evenson, Paul A.

    2002-03-01

    On 2000 August 25 from Lynn Lake, Manitoba, we conducted a balloon flight of the LEE/AESOP (Low Energy Electrons/Anti-Electron Sub Orbital Payload) payload to measure the spectrum of cosmic-ray electrons (resolved into negatrons and positrons) from 500 MeV to 3 GeV. Analysis of the data from that flight reveals a significant decrease in the cosmic-ray positron abundance from a level that remained relatively stable throughout the decade of the 1990s. Errors on the new determination are comparatively large due to the low particle fluxes at solar maximum. Nevertheless, the magnitude of the effect is consistent with predictions based on the assumption that cosmic-ray modulation effects with 22 yr periodicity are related simply and directly to charge sign and large-scale structure of the magnetic field embedded in the solar wind.

  16. The LDEF ultra heavy cosmic ray experiment

    NASA Technical Reports Server (NTRS)

    Osullivan, D.; Thompson, A.; Bosch, J.; Keegan, R.; Wenzel, K.-P.; Smit, A.; Domingo, C.

    1992-01-01

    The LDEF Ultra Heavy Cosmic Ray Experiment (UHCRE) used 16 side viewing LDEF trays giving a total geometry factor for high energy cosmic rays of 30 sq m sr. The total exposure factor was 170 sq m sr y. The experiment is based on a modular array of 192 solid state nuclear track detector stacks, mounted in sets of four in 48 pressure vessels. The extended duration of the LDEF mission has resulted in a greatly enhanced potential scientific yield from the UHCRE. Initial scanning results indicate that at least 1800 cosmic ray nuclei with Z greater than 65 were collected, including the world's first statistically significant sample of actinides. Post flight work to date and the current status of the experiment are reviewed.

  17. The LDEF ultra heavy cosmic ray experiment

    NASA Technical Reports Server (NTRS)

    Osullivan, D.; Thompson, A.; Bosch, J.; Keegan, R.; Wenzel, K.-P.; Smit, A.; Domingo, C.

    1991-01-01

    The Long Duration Exposure Facility (LDEF) Ultra Heavy Cosmic Ray Experiment (UHCRE) used 16 side viewing LDEF trays giving a total geometry factor for high energy cosmic rays of 30 sq m sr. The total exposure factor was 170 sq m sr y. The experiment is based on a modular array of 192 solid state nuclear track detector stacks, mounted in sets of 4 pressure vessels (3 experiment tray). The extended duration of the LDEF mission has resulted in a greatly enhanced potential scientific yield from the UHCRE. Initial scanning results indicate that at least 2000 cosmic ray nuclei with Z greater than 65 were collected, including the world's first statistically significant sample of actinides. Postflight work to date and the current status of the experiment are reviewed. Provisional results from analysis of preflight and postflight calibrations are presented.

  18. Progenitor model of cosmic ray knee

    NASA Astrophysics Data System (ADS)

    Bijay, Biplab; Bhadra, Arunava

    2016-01-01

    The primary energy spectrum of cosmic rays exhibits a knee at about 3 PeV where a change in the spectral index occurs. Despite many efforts, the origin of such a feature in the spectrum is not satisfactorily solved yet. Here it is proposed that the steepening of the spectrum beyond the knee may be a consequence of the mass distribution of the progenitor of the cosmic ray source. The proposed speculative model can account for all the major observed features of cosmic rays without invoking any fine tuning to match flux or spectra at any energy point. The prediction of the proposed model regarding the primary composition scenario beyond the knee is quite different from most of the prevailing models of the knee, and thereby can be discriminated from precise experimental measurement of the primary composition.

  19. Cosmic strings and ultra-high energy cosmic rays

    NASA Technical Reports Server (NTRS)

    Bhattacharjee, Pijushpani

    1989-01-01

    The flux is calculated of ultrahigh energy protons due to the process of cusp evaporation from cosmic string loops. For the standard value of the dimensionless cosmic string parameter epsilon is identical to G(sub mu) approx. = 10(exp -6), the flux is several orders of magnitude below the observed cosmic ray flux of ultrahigh energy protons. However, the flux at any energy initially increases as the value of epsilon is decreased. This at first suggests that there may be a lower limit on the value of epsilon, which would imply a lower limit on the temperature of a cosmic string forming phase transition in the early universe. However, the calculation shows that this is not the case -- the particle flux at any energy reaches its highest value at epsilon approx. = 10(exp -15) and it then decreases for further decrease of the value of epsilon. This is due to the fact that for too small values of epsilon (less than 10(exp -15)), the energy loss of the loops through the cusp evaporation process itself (rather than gravitational energy loss of the loops) becomes the dominant factor that controls the behavior of the number density of the loops at the relevant times of emission of the particles. The highest flux at any energy remains at least four orders of magnitude below the observed flux. There is thus no lower limit on epsilon.

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

    SciTech Connect

    Altamirano, A.; Navarra, G.

    2009-04-30

    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.

  1. The origin of galactic cosmic rays

    NASA Astrophysics Data System (ADS)

    Blasi, Pasquale

    2013-11-01

    One century ago Viktor Hess carried out several balloon flights that led him to conclude that the penetrating radiation responsible for the discharge of electroscopes was of extraterrestrial origin. One century from the discovery of this phenomenon seems to be a good time to stop and think about what we have understood about Cosmic Rays. The aim of this review is to illustrate the ideas that have been and are being explored in order to account for the observable quantities related to cosmic rays and to summarize the numerous new pieces of observation that are becoming available. In fact, despite the possible impression that development in this field is somewhat slow, the rate of new discoveries in the last decade or so has been impressive, and mainly driven by beautiful pieces of observation. At the same time scientists in this field have been able to propose new, fascinating ways to investigate particle acceleration inside the sources, making use of multifrequency observations that range from the radio, to the optical, to X-rays and gamma rays. These ideas can now be confronted with data. I will mostly focus on supernova remnants as the most plausible sources of Galactic cosmic rays, and I will review the main aspects of the modern theory of diffusive particle acceleration at supernova remnant shocks, with special attention for the dynamical reaction of accelerated particles on the shock and the phenomenon of magnetic field amplification at the shock. Cosmic-ray escape from the sources is discussed as a necessary step to determine the spectrum of cosmic rays at the Earth. The discussion of these theoretical ideas will always proceed parallel to an account of the data being collected especially in X-ray and gamma-ray astronomy. In the end of this review I will also discuss the phenomenon of cosmic-ray acceleration at shocks propagating in partially ionized media and the implications of this phenomenon in terms of width of the Balmer line emission. This field of research has recently experienced a remarkable growth, in that Hα lines have been found to bear information on the cosmic-ray acceleration efficiency of supernova shocks.

  2. Research in particles and fields. [cosmic rays, gamma rays, and cosmic plasma

    NASA Technical Reports Server (NTRS)

    Stone, E. C.; Buffington, A.; Davis, L., Jr.; Prince, T. A.; Vogt, R. E.

    1984-01-01

    Research activities in cosmic rays, gamma rays, and astrophysical plasmas are reviewed. Energetic particle and photon detector systems flown on spacecraft and balloons were used to carry out the investigations. Specific instruments mentioned are: the high energy isotope spectrometer telescope, the electron/isotope spectrometer, the heavy isotope spectrometer telescope, and magnetometers. Solar flares, planetary magnetospheres, element abundance, the isotopic composition of low energy cosmic rays, and heavy nuclei are among the topics receiving research attention.

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  4. Detecting ultra-high energy cosmic rays from space with unprecedented acceptance: objectives and design of the JEM-EUSO mission

    NASA Astrophysics Data System (ADS)

    Casolino, M.; Adams, J. H.; Bertaina, M. E.; Christl, M. J.; Ebisuzaki, T.; Gorodetzky, P.; Hachisu, Y.; Kajino, F.; Kawasaki, Y.; Medina-Tanco, G.; Miyamoto, H.; Ohomori, H.; Parizot, E.; Park, I.; Picozza, P.; Sakaki, N.; Santangelo, A.; Shinozaki, K.; Takizawa, Y.; Tsuno, K.; JEM-EUSO Collaboration

    2011-10-01

    The Extreme Universe Space Observatory on the Japanese Experiment Module (JEM-EUSO) of the International Space Station (ISS) is the first mission that will study from space Ultra High-Energy Cosmic Rays (UHECR). JEM-EUSO will observe Extensive Air Showers (EAS) produced by UHECRs traversing the Earth's atmosphere from above. For each event, the detector will make accurate measurements of the energy, arrival direction and nature of the primary particle using a target volume far greater than what is achievable from ground. The corresponding increase in statistics will help to clarify the origin and sources of UHECRs as well as the environment traversed during production and propagation. Possibly this will bring new light onto particle physics mechanisms operating at energies well beyond those achievable by man-made accelerators. The spectrum of scientific goals of the JEM-EUSO mission includes as exploratory objectives the detection of high-energy gamma rays and neutrinos, the study of cosmic magnetic fields, and tests of relativity and quantum gravity effects at extreme energies. In parallel JEM-EUSO will systematically perform observation of the surface of the Earth in the infra-red and ultra-violet ranges, studying also atmospheric phenomena (Transient Luminous Effects). The apparatus is a 2 t detector using Fresnel-based optics to focus the UV-light from EAS on a focal surface composed of about 6 000~multianode photomultipliers for a total of ~3 · 105 channels. A multi-layer parallel architecture has been devised to handle the data flow and select valid triggers, reducing it to a rate compatible with downlink constraints. Each processing level filters the event with increasingly complex algorithms using ASICs, FPGAs and DSPs in this order to reject spurious triggers and reduce the data rate.

  5. Galactic cosmic ray antiprotons and supersymmetry

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.; Walsh, T.; Rudaz, S.

    1985-01-01

    The physics of the annihilation of photinos is considered as a function of mass in detail, in order to obtain the energy spectra of the cosmic ray antiprotons produced under the assumption that photinos make up the missing mass in the galactic halo. The modulated spectrum is at 1 a.w. with the cosmic ray antiprotons data. A very intriguing fit is obtained to all of the present antiprotons up to 13.4 GeV data for similar to 15 GeV. A cutoff is predicted in the antiprotons spectrum at E = photino mass above which only a small flux from secondary production should remain.

  6. Isotopic composition of heavy cosmic rays

    NASA Technical Reports Server (NTRS)

    Maehl, R. C.; Isreal, M. H.; Klarmann, J.

    1973-01-01

    The mean isotopic composition was measured of even-charge cosmic ray elements with 14 equal to or less than 26 near 0.8 GeV/N using a balloon-borne ionization-chamber/Cerenkov-counter detector system. The experimental method makes use of the geomagnetic field as a magnetic spectrometer. Results indicate that the most abundant isotopes at the cosmic ray source are Si-28, S-32, and Ca-40, like the solar system; but Fe-54, unlike the solar system.

  7. Search for antimatter in primary cosmic rays.

    NASA Technical Reports Server (NTRS)

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

    1972-01-01

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

  8. The isotopic composition of cosmic ray calcium

    NASA Technical Reports Server (NTRS)

    Krombel, K. E.; Wiedenbeck, M. E.

    1985-01-01

    Data from the high energy cosmic ray experiment on the international sun earth explorer 3 (ISEE-3) spacecraft have been used to study the isotopic composition of cosmic ray calcium at an energy of approx. 260 MeV/amu. The arriving calcium is found to consist of (32 + or - 6)%. A propagation model consistent with both the light and the subiron secondary element abundances was used for the interpretation of the observed calcium composition. The measured 42Ca+43Ca+44Ca abundance is consistent with the calculated secondary production, while the 40Ca abundance implies a source ratio of 40Ca/Fe = (7.0 + or - 1.7)%.

  9. Time variation of galactic cosmic rays

    NASA Technical Reports Server (NTRS)

    Evenson, Paul

    1988-01-01

    Time variations in the flux of galactic cosmic rays are the result of changing conditions in the solar wind. Maximum cosmic ray fluxes, which occur when solar activity is at a minimum, are well defined. Reductions from this maximum level are typically systematic and predictable but on occasion are rapid and unexpected. Models relating the flux level at lower energy to that at neutron monitor energy are typically accurate to 20 percent of the total excursion at that energy. Other models, relating flux to observables such as sunspot number, flare frequency, and current sheet tilt are phenomenological but nevertheless can be quite accurate.

  10. Cosmic rays near the heliospheric current sheet

    NASA Technical Reports Server (NTRS)

    Kota, J.; Jokipii, J. R.

    1982-01-01

    A discussion of full, three-dimensional model simulations of the solar modulation of galactic cosmic rays, including drift, is presented. Particular emphasis is on the variation of the cosmic-ray intensity near the heliospheric current sheet. It is shown that the model quite naturally produces a negative gradient away from a wavy current sheet as seen by an observer on the earth. It is concluded that recent observations of Newkirk and Lockwood (1981) are not in conflict with these model results, and hence are consistent with modulation models in which drift plays an important role.

  11. Heliosphere Dimension and Cosmic Ray Modulation

    NASA Astrophysics Data System (ADS)

    Bobik, P.; Boschini, M. J.; Consolandi, C.; Della Torre, S.; Gervasi, M.; Grandi, D.; Kudela, K.; Noventa, F.; Pensotti, S.; Rancoita, P. G.; Rozza, D.

    2012-08-01

    The differential intensities of Cosmic Rays at Earth were calculated using a 2D stochastic Montecarlo diffusion code and compared with observation data. We evaluated the effect of stretched and compressed heliospheres on the Cosmic Ray intensities at the Earth. This was studied introducing a dependence of the diffusion parameter on the heliospherical size. Then, we found that the optimum value of the heliospherical radius better accounting for experimental data. We also found that the obtained values depends on solar activity. Our results are compatible with Voyager observations and with models of heliospherical size modulation.

  12. Gamma-ray astronomy and cosmic ray origin problem

    NASA Astrophysics Data System (ADS)

    Berezhko, E.

    The purpose of this talk is to review some recent work on the model for the origin of the bulk of Galactic cosmic rays (CRs), namely that they are produced by diffusive shock acceleration in shock waves associated with supernova remnants (SNRs). This is currently the modern theory for the origin of Galactic CRs. Selfconsistent nonlinear theory of CR acceleration in SNRs developed during the last decade explains the main characteristics of the observed CR spectrum at least up to the knee energy. Direct information about CR population in young Galactic SNRs obtained from the properties of the nonthermal radiation is analysed. Electron CR component is visible ia a wide range of radiation, which they produce in SNRs, from radio to gamma-ray emission, whereas in the case of nuclear CR component gamma-rays detection is the only possibility to see it. If this nuclear component is strongly enhanced inside SNRs then through inelastic nuclear collisions, leading to pion production and subsequent decay, gamma-rays will be produced at the detectable level. It is argued that the existing data confirm very efficient acceleration of nuclear CRs in SNRs with the efficiency consistent with the requirements for the Galactic CR energy budget and that the theory is not only able to describe the CR dynamics and acceleration in SNRs, but that it constitutes in addition a reliable method to quantitatively determine the effective (strongly amplified) SNR magnetic field strength which is produced in the acceleration process.

  13. Cosmic ray albedo gamma rays from the quiet sun

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

    We estimate the flux of gamma-rays that result from collisions of high energy galactic cosmic rays with the solar atmosphere. An important aspect of our model is the propagation of cosmic rays through the magnetic fields of the inner solar systems. We use diffusion to model propagation down to the bottom of the corona. Below the corona we trace particle orbits through the photospheric fields to determine the location of cosmic ray interactions in the solar atmosphere and evolve the resultant cascades. For our nominal choice of parameters, we predict an integrated flux of gamma rays (at 1 AU) of F(E(sub gamma) greater than 100 MeV) approximately = 5 x 10(exp -8)/sq cm sec. This can be an order of magnitude above the galactic background and should be observable by the Energetic Gamma Ray experiment telescope (EGRET).

  14. Research in cosmic and gamma ray astrophysics: Cosmic physics portion

    NASA Technical Reports Server (NTRS)

    Stone, Edward C.; Mewaldt, Richard A.; Schindler, Stephen

    1993-01-01

    Research in particle astrophysics at the Space Radiation Laboratory (SRL) of the California Institute of Technology is supported under NASA Grant NAGW-1919. A three-year proposal for continuation of support was submitted a year ago and put into effect 1 October 1992. This report is the combined progress report and continuation application called for under the Federal Demonstration Project. Gamma-ray Astrophysics at SRL is separately supported under NAGW-1919 and will be separately summarized and proposed. This report will document progress and plans for our particle spectroscopy activities and for related data analysis, calibration, and community service activities. A bibliography and a budget will be attached as appendices. The Caltech SRL research program includes a heavy emphasis on elemental and isotopic spectroscopy of energetic particles in the cosmic radiation; in solar, interplanetary, and anomalous 'cosmic' radiation; and in planetary magnetospheres as discussed.

  15. Microphysics of Cosmic Ray Driven Plasma Instabilities

    NASA Astrophysics Data System (ADS)

    Bykov, A. M.; Brandenburg, A.; Malkov, M. A.; Osipov, S. M.

    Energetic nonthermal particles (cosmic rays, CRs) are accelerated in supernova remnants, relativistic jets and other astrophysical objects. The CR energy density is typically comparable with that of the thermal components and magnetic fields. In this review we discuss mechanisms of magnetic field amplification due to instabilities induced by CRs. We derive CR kinetic and magnetohydrodynamic equations that govern cosmic plasma systems comprising the thermal background plasma, comic rays and fluctuating magnetic fields to study CR-driven instabilities. Both resonant and non-resonant instabilities are reviewed, including the Bell short-wavelength instability, and the firehose instability. Special attention is paid to the longwavelength instabilities driven by the CR current and pressure gradient. The helicity production by the CR current-driven instabilities is discussed in connection with the dynamo mechanisms of cosmic magnetic field amplification.

  16. Microphysics of Cosmic Ray Driven Plasma Instabilities

    NASA Astrophysics Data System (ADS)

    Bykov, A. M.; Brandenburg, A.; Malkov, M. A.; Osipov, S. M.

    2013-10-01

    Energetic nonthermal particles (cosmic rays, CRs) are accelerated in supernova remnants, relativistic jets and other astrophysical objects. The CR energy density is typically comparable with that of the thermal components and magnetic fields. In this review we discuss mechanisms of magnetic field amplification due to instabilities induced by CRs. We derive CR kinetic and magnetohydrodynamic equations that govern cosmic plasma systems comprising the thermal background plasma, comic rays and fluctuating magnetic fields to study CR-driven instabilities. Both resonant and non-resonant instabilities are reviewed, including the Bell short-wavelength instability, and the firehose instability. Special attention is paid to the longwavelength instabilities driven by the CR current and pressure gradient. The helicity production by the CR current-driven instabilities is discussed in connection with the dynamo mechanisms of cosmic magnetic field amplification.

  17. The Heliosphere and Galactic Cosmic Rays - Duration: 39 seconds.

    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...

  18. The Isotopic Composition of Cosmic-Ray Iron and Nickel

    NASA Technical Reports Server (NTRS)

    Wiedenbeck, M.; Binns, W.; Christian, E.; Cummings, A.; George, J.; Hink, P.; Klarmann, J.; Leske, R.; Lijowski, M.; Mewaldt, R.; Stone, E.; Rosenvinge, T. von

    2000-01-01

    Observations from the Cosmic Ray Isotope Spectrometer (CRIS) on ACE have been used to derive contraints on the locations, physical conditions, and time scales for cosmic-ray acceleration and transport.

  19. The Mystery of Ultra-High Energy Cosmic Rays

    SciTech Connect

    Olinto, Angela V.

    2006-07-11

    Cosmic rays with energies well above 1019 eV are messengers of an unknown extremely high-energy universe. The current state and future prospects of ultra high energy cosmic ray physics are briefly reviewed.

  20. Propagation of Cosmic Rays and Diffuse Galactic Gamma Rays

    NASA Technical Reports Server (NTRS)

    Moskalenko, Igor V.

    2004-01-01

    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.

  1. Numerical likelihood analysis of cosmic ray anisotropies

    SciTech Connect

    Carlos Hojvat et al.

    2003-07-02

    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.

  2. Cosmic Ray Origin, Acceleration and Propagation

    NASA Technical Reports Server (NTRS)

    Baring, Matthew G.

    2000-01-01

    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.

  3. Believability of signals from cosmic ray sources

    SciTech Connect

    Goodman, M.

    1990-11-01

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

  4. Cosmic Ray Transport in the Distant Heliosheath

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

    The character of energetic particle transport in the distant heliosheath and especially in the vicinity of the heliopause could be quite distinct from the other regions of the heliosphere. The magnetic field structure is dominated by a tightly wrapped oscillating heliospheric current sheet which is transported to higher latitudes by the nonradial heliosheath flows. Both Voyagers have, or are expected to enter a region dominated by the sectored field formed during the preceding solar maximum. As the plasma flow slows down on approach to the heliopause, the distance between the folds of the current sheet decreases to the point where it becomes comparable to the cyclotron radius of an energetic ion, such as a galactic cosmic ray. Then, a charged particle can effectively drift across a stack of magnetic sectors with a speed comparable with the particle s velocity. Cosmic rays should also be able to efficiently diffuse across the mean magnetic field if the distance between sector boundaries varies. The region of the heliopause could thus be much more permeable to cosmic rays than was previously thought. This new transport proposed mechanism could explain the very high intensities (approaching the model interstellar values) of galactic cosmic rays measured by Voyager 1 during 2010-2011.

  5. Actinides and the sources of cosmic rays

    NASA Astrophysics Data System (ADS)

    Pfeiffer, B.; Kratz, K.-L.; Lingenfelter, R. E.; Higdon, J. C.

    2004-02-01

    The abundances of the actinide elements in the cosmic rays can provide critical constraints on the major sites of their acceleration. Using recent calculations of the r-process yields in core-collapse supernovae (SNe), we have determined the actinide abundances averaged over various assumed time intervals for their supernovae generation and their cosmic-ray acceleration. Using standard Galactic chemical evolution models, we have also determined the expected actinide abundances in the present interstellar medium. From these two components, we have calculated the U/Th and other actinide abundances expected in the SN-active cores of superbubbles, as a function of their ages and mean metallicity. We calculate the expected actinide abundances in cosmic-rays accelerated by Galactic SNe. We find that the current measurements of actinide/Pt-group and preliminary estimates of the UPuCM/Th ratio in cosmic rays are all consistent with the expected values if superbubble cores have mean metallicities of around three times solar. Future measurements of the abundance ratios will help to solve these questions. First results of experiments performed on the MIR space station (ECCO) and with balloon flights (TIGER) are promising.

  6. A database of charged cosmic rays

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

    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

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

    NASA Astrophysics Data System (ADS)

    Moharana, Reetanjali; Razzaque, Soebur

    2015-08-01

    Cosmic neutrino events detected by the IceCube Neutrino Observatory with energy 0gtrsim 3 TeV have poor angular resolutions to reveal their origin. Ultrahigh-energy cosmic rays (UHECRs), with better angular resolutions at 0>6 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 0>= 10 EeV UHECR arrival directions at confidence level ? 90%. The strength of the correlation decreases with decreasing UHECR energy and no correlation exists at energy 0~ 6 EeV . A search in astrophysical databases within 3o of the arrival directions of UHECRs with energy 0>= 10 EeV, that are correlated with the IceCube cosmic neutrinos, resulted in 18 sources from the Swift-BAT X-ray catalog with redshift z<= 0.06. We also found 3 objects in the Khr catalog of radio sources using the same criteria. The sources are dominantly Seyfert galaxies with Cygnus A being the most prominent member. We calculate the required neutrino and UHECR fluxes to produce the observed correlated events, and estimate the corresponding neutrino luminosity (25 TeV-2.2 PeV) and cosmic-ray luminosity (500 TeV-180 EeV), assuming the sources are the ones we found in the Swift-BAT and Khr catalogs. We compare these luminosities with the X-ray luminosity of the corresponding sources and discuss possibilities of accelerating protons to 0gtrsim 10 EeV and produce neutrinos in these sources.

  8. Cosmic rays from primordial black holes

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

    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.

  9. Galactic winds driven by cosmic rays

    NASA Technical Reports Server (NTRS)

    Ipavich, F. M.

    1975-01-01

    Cosmic rays traveling through a magnetized plasma with mean velocity greater than the Alfven speed can become coupled to the plasma by the emission of magnetohydrodynamic waves. Using a time-independent, spherically symmetric, hydrodynamic treatment, we show that cosmic rays escaping from a galaxy can carry along thermal gas and produce a 'galactic wind'. Solutions indicate that a typical galaxy can lose mass at a rate of about 1 to 10 million solar masses per year and energy at a rate of about 10 to the 40th to 10 to the 42nd ergs per sec. The possible role of galactic winds in radio and X-ray sources is explored. A model is proposed to explain the X-ray emission observed from clusters of galaxies.

  10. Validation of Cosmic Ray Ionization Model CORIMIA applied for solar energetic particles and Anomalous Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Asenovski, S.; Velinov, P.; Mateev, L.

    2016-02-01

    Based on the electromagnetic interaction between the cosmic ray (CR) and the atmospheric neutral constituents, CORIMIA (COsmic Ray Ionization Model) gives an estimation of the dynamical ionization condition of the lower ionosphere and middle atmosphere (about 30-120 km). Galactic Cosmic Rays (GCR), modified by solar wind and later by geomagnetic and atmospheric cut offs, produce ionization in the entire atmosphere. In this paper we show the GCR ionization in periods of solar minimum and maximum. Despite the considerably lower energies than GCR, Anomalous Cosmic Rays (ACR) contribute to the ionization state mostly over the polar regions and as we present here this contribution is comparable with those of GCR. Solar energetic particles (SEP), which differ vastly from one another for different solar events, can be responsible for significant ionization over the high latitude regions. Here we compare flows of SEP caused by two of the most powerful solar proton events at February 23, 1956 and January 20, 2005.

  11. Lithium Nucleosynthesis in Cosmology and Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Fields, B. D.

    2001-08-01

    Big bang nucleosynthesis (BBN) describes the production of the light elements 1 H, 2 H, 3 He, 4 He, and 7 Li in the early universe. BBN theory, together with light element observations, provides the best measure for now of the cosmic baryon content. The observed primordial Li abundance is determined from ancient, metal-poor (extreme Population II) stars. However, the Li abundance measured in these stars also contains contributions from Galactic cosmic ray nucleosynthesis, predominantly via α + alpha →6,7 Li. This Galactic component should lead to a small but nonzero slope in Li vs. Fe (or O), and such a trend has now been observed. It is shown that the cosmic-ray Li component can be determined in a model-independent, empirical manner. Subtracting this component leads to a more accurate estimate of the primordial Li abundance. This refinement improves the BBN estimate of the cosmic baryon density, which will soon be independently and strongly tested by measurements of anisotropy in the cosmic microwave background radiation.

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

    NASA Technical Reports Server (NTRS)

    Barghouty, A. F.

    2009-01-01

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

  13. Re-evaluation of cosmic ray cutoff terminology

    NASA Technical Reports Server (NTRS)

    Cooke, D. J.; Humble, J. E.; Shea, M. A.; Smart, D. F.; Lund, N.; Rasmussen, I. L.; Byrnak, B.; Goret, P.; Petrou, N.

    1985-01-01

    The study of cosmic ray access to locations inside the geomagnetic field has evolved in a manner that has led to some misunderstanding and misapplication of the terminology originally developed to describe particle access. This paper presents what is believed to be a useful set of definitions for cosmic ray cutoff terminology for use in theoretical and experimental cosmic ray studies.

  14. Introduction to the study of cosmic rays and their interaction with the terrestrial atmosphere

    NASA Astrophysics Data System (ADS)

    Schuch, Luiz Alexandre

    A broad survey is presented on the origin and composition of cosmic rays, its modulation associated with solar activity, its interaction with the Earth's magnetic field and atmosphere and its energy spectrum at sea level. Special attention is given to detection systems and to the effects of cosmic rays on material and live beings, especially man.

  15. Cosmic ray propagation with CRPropa 3

    NASA Astrophysics Data System (ADS)

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

    2015-05-01

    Solving the question of the origin of ultra-high energy cosmic rays (UHECRs) requires the development of detailed simulation tools in order to interpret the experimental data and draw conclusions on the UHECR universe. CRPropa is a public Monte Carlo code for the galactic and extragalactic propagation of cosmic ray nuclei above ∼ 1017 eV, as well as their photon and neutrino secondaries. In this contribution the new algorithms and features of CRPropa 3, the next major release, are presented. CRPropa 3 introduces time-dependent scenarios to include cosmic evolution in the presence of cosmic ray deflections in magnetic fields. The usage of high resolution magnetic fields is facilitated by shared memory parallelism, modulated fields and fields with heterogeneous resolution. Galactic propagation is enabled through the implementation of galactic magnetic field models, as well as an efficient forward propagation technique through transformation matrices. To make use of the large Python ecosystem in astrophysics CRPropa 3 can be steered and extended in Python.

  16. Gamma-ray astronomy and the origin of cosmic rays

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1978-01-01

    New surveys of galactic gamma ray emission together with millimeter wave radio surveys indicated that cosmic rays were produced as the result of supernova explosions in our galaxy with the most intense production occurring in a Great Galactic Ring about 35,000 light years in diameter where supernova remnants and pulsars were concentrated.

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

    ERIC Educational Resources Information Center

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

    2001-01-01

    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…

  18. Cosmic rays and the Monogem supernova remnant

    NASA Astrophysics Data System (ADS)

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

    2004-10-01

    Recent findings indicate that the Monogem Ring and the associated pulsar PSR B0656 + 14 may be the `Single Source' responsible for the formation of the sharp knee in the cosmic ray energy spectrum at 3 PeV. The energy spectrum of cosmic rays expected for the Monogem Ring supernova remnant (SNR) from our SNR acceleration model [J. Phys. G: Nucl. Part. Phys. 27 (2001) 941] has been published by us elsewhere [J. Phys. G: Nucl. Part. Phys. 29 (2003) 709] . In this paper we go on to estimate the contribution of the pulsar B0656 + 14 to the cosmic rays in the PeV region. We conclude that although the pulsar can contribute to the formation of the knee, it cannot be the dominant source of it and an SNR is still needed. We also examine the possibility of the pulsar giving the peak of the extensive air shower (EAS) intensity observed from the region inside the Monogem Ring [ApJ Lett. 597 (2003) L129]. The estimates of the gamma-ray flux produced by cosmic ray particles from this pulsar indicate that it can be the source of the observed peak, if the particles were confined within the SNR during a considerable fraction of its total age. The flux of gamma quanta at PeV energies has a high sensitivity to the duration of the confinement. The estimates of this time and of the following diffusion of cosmic rays from the confinement volume turn out to be in remarkable agreement with the time needed for these cosmic rays to propagate to the solar system and to form the observed knee in the cosmic ray energy spectrum. Other possible mechanisms for the production of particles which could give rise to the observed narrow peak in the EAS intensity were also examined. Electrons scattered on the microwave background or on X-rays, emitted by SNR, cannot be responsible for the gamma-quanta in the peak. Neutrons produced in PP-collisions or released from the disintegration of accelerated nuclei seem to be also unable to create the peak since they cannot give the observed flux. If the experimental EAS results concerning a point-like source are confirmed, they can be important, since they will give evidence for the acceleration of protons or heavier nuclei by the pulsar; they will give evidence for the existence of a confinement mechanism in SNR; they will confirm that cosmic rays produced by the Monogem Ring SNR and associated pulsar B0656 + 14 were released recently giving rise to the formation of the sharp knee and the observed narrow peak in the EAS intensity; they will give strong support for the Monogem Ring SNR and the associated pulsar B0656 + 14 being identified as the Single Source proposed in our Single Source Model of the knee. examined mechanism are made.

  19. Cosmic X-ray physics

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

    The analysis of the beryllium-filtered data from Flight 17.020 was completed. The data base provided by the Wisconsin diffuse X-ray sky survey is being analyzed by correlating the B and C band emission with individual velocity components of neutral hydrogen. Work on a solid state detector to be used in high resolution spectroscopy of diffuse or extend X-ray sources is continuing. A series of 21 cm observations was completed. A paper on the effects of process parameter variation on the reflectivity of sputter-deposited tungsten-carvon multilayers was published.

  20. Nuclear composition of solar cosmic rays

    NASA Technical Reports Server (NTRS)

    Hovestadt, D.

    1974-01-01

    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.

  1. Terrestrial effects of high energy cosmic rays

    NASA Astrophysics Data System (ADS)

    Atri, Dimitra

    On geological timescales, the Earth is likely to be exposed to higher than the usual flux of high energy cosmic rays (HECRs) from astrophysical sources such as nearby supernovae, gamma ray bursts or by galactic shocks. These high-energy particles strike the Earth's atmosphere, initiating an extensive air shower. As the air shower propagates deeper, it ionizes the atmosphere by producing charged secondary particles and photons. Increased ionization leads to changes in atmospheric chemistry, resulting in ozone depletion. This increases the flux of solar UVB radiation at the surface, which is potentially harmful to living organisms. Increased ionization affects the global electrical circuit, which could enhance the low-altitude cloud formation rate. Secondary particles such as muons and thermal neutrons produced as a result of hadronic interactions of the primary cosmic rays with the atmosphere are able to reach the ground, enhancing the biological radiation dose. The muon flux dominates the radiation dose from cosmic rays causing damage to DNA and an increase in mutation rates and cancer, which can have serious biological implications for surface and sub-surface life. Using CORSIKA, we perform massive computer simulations and construct lookup tables for 10 GeV - 1 PeV primaries, which can be used to quantify these effects from enhanced cosmic ray exposure to any astrophysical source. These tables are freely available to the community and can be used for other studies. We use these tables to study the terrestrial implications of galactic shock generated by the infall of our galaxy toward the Virgo cluster. Increased radiation dose from muons could be a possible mechanism explaining the observed periodicity in biodiversity in paleobiology databases.

  2. Measurement of the cosmic ray spectrum above 4×1018 eV using inclined events detected with the Pierre Auger Observatory

    SciTech Connect

    Aab, Alexander

    2015-08-26

    A measurement of the cosmic-ray spectrum for energies exceeding 4×1018 eV is presented, which is based on the analysis of showers with zenith angles greater than 60° detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above 5.3×1018 eV, the ``ankle'', the flux can be described by a power law E–γ with index γ=2.70 ± 0.02 (stat) ± 0.1 (sys) followed by a smooth suppression region. For the energy (Es) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find Es=(5.12±0.25 (stat)+1.0–1.2 (sys))×1019 eV.

  3. Ninteenth International Cosmic Ray Conference. OG Sessions, Volume 1

    NASA Technical Reports Server (NTRS)

    Jones, F. C. (Compiler)

    1985-01-01

    Contributed papers addressing cosmic ray origin and galactic phenomena are compiled. The topic areas covered in this volume include gamma ray bursts, gamma rays from point sources, and diffuse gamma ray emission.

  4. The Cosmic Gamma-Ray Bursts

    NASA Astrophysics Data System (ADS)

    Djorgovski, S. G.; Frail, D. A.; Kulkarni, S. R.; Sari, R.; Bloom, J. S.; Galama, T. J.; Harrison, F. A.; Price, P. A.; Fox, D.; Reichart, D. E.; Yost, S.; Berger, E.; Diercks, A.; Goodrich, R.; Chaffee, F.

    2002-12-01

    Cosmic γ-ray bursts are one of the great frontiers of astrophysics today. They are a playground of relativists and observers alike. They may teach us about the death of stars and the birth of black holes, the physics in extreme conditions, and help us probe star formation in the distant and obscured universe. In this review we summarise some of the remarkable progress in this field over the past few years. While the nature of the GRB progenitors is still unsettled, it now appears likely that at least some bursts originate in explosions of very massive stars, or at least occur in or near the regions of massive star formation. The physics of the burst afterglows is reasonably well understood, and has been tested and confirmed very well by the observations. Bursts are found to be beamed, but with a broad range of jet opening angles; the mean γ-ray energies after the beaming corrections are ~ 1051 erg. Bursts are associated with faint ( ~ 25 mag) galaxies at cosmological redshifts, with ~ 1. The host galaxies span a range of luminosities and morphologies, but appear to be broadly typical for the normal, actively star-forming galaxy populations at comparable redshifts and magnitudes. Some of the challenges for the future include: the nature of the short bursts and possibly other types of bursts and transients; use of GRBs to probe the obscured star formation in the universe, and possibly as probes of the very early universe; and their detection as sources of high-energy particles and gravitational waves.

  5. Elemental technetium and promethium as cosmic-ray clocks

    NASA Technical Reports Server (NTRS)

    Drach, J.; Salamon, M. H.

    1987-01-01

    The possibility of using elemental Tc (Z = 43) and Pm (Z = 61) as clocks to measure the mean cosmic-ray confinement time in the Galaxy, tau(epsilon) is considered. For this purpose it is necessary to estimate the unknown beta(+) decay half-lives of several Tc and Pm isotopes; these estimates are obtained using beta-decay systematics. In the case of Tc it is possible to estimate the half-lives sufficiently well and show that this element can indeed be used as a cosmic-ray clock; in the case of Pm the half-lives are too uncertain to permit any conclusion. In order to make meaningful measurement of tau(epsilon) using elemental Tc, a comsic-ray detector must have a charge resolution less than about 0.25e in the region around Tc, and enough collecting power to detect a few hundred Tc nuclei.

  6. Elemental technetium and promethium as cosmic-ray clocks

    SciTech Connect

    Drach, J.; Salamon, M.H.

    1987-08-01

    The possibility of using elemental Tc (Z = 43) and Pm (Z = 61) as clocks to measure the mean cosmic-ray confinement time in the Galaxy, tau(epsilon) is considered. For this purpose it is necessary to estimate the unknown beta(+) decay half-lives of several Tc and Pm isotopes; these estimates are obtained using beta-decay systematics. In the case of Tc it is possible to estimate the half-lives sufficiently well and show that this element can indeed be used as a cosmic-ray clock; in the case of Pm the half-lives are too uncertain to permit any conclusion. In order to make meaningful measurement of tau(epsilon) using elemental Tc, a comsic-ray detector must have a charge resolution less than about 0.25e in the region around Tc, and enough collecting power to detect a few hundred Tc nuclei. 32 references.

  7. Determination and study of the cosmic-ray composition above 100 TeV

    SciTech Connect

    Sinnis, G.; Haines, T.J.; Hoffman, C.M.

    1998-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The goal of this project was to develop a new technique using ground-based measurements to determine the cosmic-ray composition at energies around 10{sup 15} eV (the knee in the cosmic-ray spectrum). Cosmic rays are high-energy nuclei that continuously bombard the earth. Though cosmic rays were first detected in the 1870s it wasn`t until 1915 that their cosmic origin was established. At present, the authors still do not know the source of cosmic rays. At energies above 50 TeV (1 TeV = 1 trillion electron-volts) they do not know the composition of the cosmic rays. At about 5 PeV (1PeV = 10{sup 15} eV) the cosmic ray spectrum steepens. Knowledge of the composition above and below this point can help determine the origin of cosmic rays.

  8. Antiprotons in cosmic rays and their implications

    NASA Technical Reports Server (NTRS)

    Stephens, S. A.

    1989-01-01

    A brief description of the experiments carried out so far to measure the energy spectrum of antiprotons is made and the reason for the excitement in this field of research is elucidated. The observed spectrum appears to be different form the other components of cosmic rays. Various physical processes by which antiprotons could be created are summarized. The equilibrium spectrum of antiprotons in the Galaxy, arising from each of these processes, is derived for different propagation models. It is shown that no single model can predict correctly the observed data over the entire energy region. However, the recent data at low energies suggest that the conventional models with large amount of matter traversal by cosmic rays, either in the source region or during propagation, can reproduce the data closely. The implications of these propagation models for other components are discussed and the need for more observations is emphasized.

  9. Search for Antihelium in the Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Golden, R. L.; Stochaj, S. J.; Stephens, S. A.; Moiseev, A. A.; Ormes, J. F.; Streitmatter, R. E.; Bowen, T.; Moats, A.; Lloyd-Evans, J.

    1997-04-01

    On 1987 August 22 a balloon flight was conducted using the Goddard Space Flight Center Low-Energy Antiproton configuration of the New Mexico State University balloon-borne magnet spectrometer. The launch site was Prince Albert, Saskatchewan, Canada. The balloon flew at an average atmospheric depth of 4.7 g cm-2 for more than 22 hr. During this period a sample of 4.2 × 104 helium nuclei was gathered. No antihelium candidates were found in this sample. The resultant upper limit for the ratio of antihelium to helium in cosmic rays over the rigidity interval from 1 to 25 GV/c is 9 × 10-5 at 95% confidence. This limit is below the predicted level, assuming equal matter and antimatter in the extragalactic cosmic rays.

  10. The Pierre Auger Cosmic Ray Observatory

    SciTech Connect

    Aab, Alexander

    2015-07-08

    The Pierre Auger Observatory, located on a vast, high plain in western Argentina, is the world's largest cosmic ray observatory. The objectives of the Observatory are to probe the origin and characteristics of cosmic rays above 1017 eV and study the interactions of these, the most energetic particles observed in nature. The Auger design features an array of 1660 water Cherenkov particle detector stations spread over 3000 km2 overlooked by 24 air fluorescence telescopes. Additionally, three high elevation fluorescence telescopes overlook a 23.5 km2, 61-detector infilled array with 750 m spacing. The Observatory has been in successful operation since completion in 2008 and has recorded data from an exposure exceeding 40,000 km2 sr yr. This paper describes the design and performance of the detectors, related subsystems and infrastructure that make up the Observatory.

  11. Galactic cosmic ray heavy primary secondary doses

    NASA Technical Reports Server (NTRS)

    Wilkinson, M. C.; Curtis, S. B.

    1972-01-01

    Results of a calculation which estimates the heavy primary secondary doses from cosmic ray interaction data are reported. The incident galactic cosmic ray heavy primary spectrum is represented as the sum of helium, nitrogen, magnesium, and iron components. The incident iron nuclei are allowed to fragment into lesser Z secondaries, which are assumed to travel in the same direction and start with the same energy per nucleon as the interacting primary. The total emergent particle energy spectra and dose are then presented for the galactic heavy primary spectrum incident on aluminum and tissue slabs. The importance of the fragmentation parameters assumed is also evaluated. The total dose from the heavy primaries and their secondaries is found to be reduced by only a factor of two in 20 g/sq cm of shielding.

  12. Radiative Energy Loss by Galactic Cosmic Rays

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    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.

  13. The Pierre Auger Cosmic Ray Observatory

    DOE PAGESBeta

    Aab, Alexander

    2015-07-08

    The Pierre Auger Observatory, located on a vast, high plain in western Argentina, is the world's largest cosmic ray observatory. The objectives of the Observatory are to probe the origin and characteristics of cosmic rays above 1017 eV and study the interactions of these, the most energetic particles observed in nature. The Auger design features an array of 1660 water Cherenkov particle detector stations spread over 3000 km2 overlooked by 24 air fluorescence telescopes. Additionally, three high elevation fluorescence telescopes overlook a 23.5 km2, 61-detector infilled array with 750 m spacing. The Observatory has been in successful operation since completionmore » in 2008 and has recorded data from an exposure exceeding 40,000 km2 sr yr. This paper describes the design and performance of the detectors, related subsystems and infrastructure that make up the Observatory.« less

  14. Cosmic Rays, Solar Activity and the Climate

    NASA Astrophysics Data System (ADS)

    Sloan, T.

    2013-02-01

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

  15. Cosmic Ray Electron Science with GLAST

    NASA Technical Reports Server (NTRS)

    Ormes, J. F.; Moiseev, Alexander

    2007-01-01

    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.

  16. Cosmic rays, solar activity and the climate

    NASA Astrophysics Data System (ADS)

    Sloan, T.; Wolfendale, A. W.

    2013-12-01

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

  17. New insights from cosmic gamma rays

    NASA Astrophysics Data System (ADS)

    Roland, Diehl

    2016-04-01

    The measurement of gamma rays from cosmic sources at ~MeV energies is one of the key tools for nuclear astrophysics, in its study of nuclear reactions and their impacts on objects and phenomena throughout the universe. Gamma rays trace nuclear processes most directly, as they originate from nuclear transitions following radioactive decays or high-energy collisions with excitation of nuclei. Additionally, the unique gamma-ray signature from the annihilation of positrons falls into this astronomical window and is discussed here: Cosmic positrons are often produced from β-decays, thus also of nuclear physics origins. The nuclear reactions leading to radioactive isotopes occur inside stars and stellar explosions, which therefore constitute the main objects of such studies. In recent years, both thermonuclear and core-collapse supernova radioactivities have been measured though 56Ni, 56Co, and 44Ti lines, and a beginning has thus been made to complement conventional supernova observations with such measurements of the prime energy sources of supernova light created in their deep interiors. The diffuse radioactive afterglow of massive-star nucleosynthesis in gamma rays is now being exploited towards astrophysical studies on how massive stars feed back their energy and ejecta into interstellar gas, as part of the cosmic cycle of matter through generations of stars enriching the interstellar gas and stars with metals. Large interstellar cavities and superbubbles have been recognised to be the dominating structures where new massive-star ejecta are injected, from 26Al gamma-ray spectroscopy. Also, constraints on the complex interiors of stars derive from the ratio of 60Fe/26Al gamma rays. Finally, the puzzling bulge-dominated intensity distribution of positron annihilation gamma rays is measured in greater detail, but still not understood; a recent microquasar flare provided evidence that such objects may be prime sources for positrons in interstellar space, rather than distributed nucleosynthesis. We also briefly discuss the status and prospects for astronomy with telescopes for the nuclear-radiation energy window.

  18. Recent cosmic-ray antiproton measurements and astrophysical implications

    NASA Technical Reports Server (NTRS)

    Buffington, A.; Schindler, S. M.

    1981-01-01

    Cosmic-ray antiprotons have been detected by a new balloon-borne experiment which covers the energy range between 130 and 320 MeV. Fourteen detected events yield a measured flux of 1.7 plus or minus 0.5 x 10 to the -4th antiprotons/sq m sr s MeV. The corresponding antiproton/proton ratio is 2.2 plus or minus 0.6 x 10 to the -4th, only slightly smaller than the ratio observed by other experiments at higher energies. The measured flux is significantly larger than predicted, and some cosmic-ray models which could explain this result are discussed.

  19. Measuring cosmic ray radio signals at the Pierre Auger Observatory

    NASA Astrophysics Data System (ADS)

    Dallier, Richard; Pierre Auger Collaboration

    2011-02-01

    The recent results of the LOPES and CODALEMA experiments open the door to a renewal of the radio technique for cosmic ray induced shower measurements. The demonstration has been done of its potential and performances at energies below 1018 eV, this upper limit being due to the small scale of the current experiments. A natural stage toward the improvement of the method is thus to install radio detectors in association with a large cosmic ray detector such as Auger. Besides surface and fluorescence detection, radio detection could be an alternative method, providing a complementary information. The Pierre Auger Collaboration has thus engaged a R&D effort which will lead to the installation of a radio engineering array covering 20 km2 on its southern site. Outline of the technique, results of the first phase of the tests and current plans for the future engineering array will be presented.

  20. Gamma rays from cosmic rays in supernova remnants

    NASA Astrophysics Data System (ADS)

    Dermer, C. D.; Powale, G.

    2013-05-01

    Context. Cosmic rays are thought to be accelerated at supernova remnant (SNR) shocks, but obtaining conclusive evidence for this hypothesis is difficult. Aims: New data from ground-based γ-ray telescopes and the Large Area Telescope on the Fermi Gamma-ray Space Telescope are used to test this hypothesis. A simple model for γ-ray production efficiency is compared with measured γ-ray luminosities of SNRs, and the GeV to TeV fluxes ratios of SNRs are examined for correlations with SNR ages. Methods: The supernova explosion is modeled as an expanding spherical shell of material that sweeps up matter from the surrounding interstellar medium (ISM). The accumulated kinetic energy of the shell, which provides the energy available for nonthermal particle acceleration, changes when matter is swept up from the ISM and the SNR shell decelerates. A fraction of this energy is assumed to be converted into the energy of cosmic-ray electrons or protons. Three different particle radiation processes - nuclear pion-production interactions, nonthermal electron bremsstrahlung, and Compton scattering - are considered. Results: The efficiencies for γ-ray production by these three processes are compared with γ-ray luminosities of SNRs. Our results suggest that SNRs become less γ-ray luminous at ≳104 yr, and are consistent with the hypothesis that supernova remnants accelerate cosmic rays with an efficiency of ≈10% for the dissipation of kinetic energy into nonthermal cosmic rays. Weak evidence for an increasing GeV to TeV flux ratio with SNR age is found.

  1. Search for cosmic-ray antimatter

    NASA Technical Reports Server (NTRS)

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

    1975-01-01

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

  2. Cosmic Ray Induced Bit-Flipping Experiment

    NASA Astrophysics Data System (ADS)

    Pu, Ge; Callaghan, Ed; Parsons, Matthew; Cribflex Team

    2015-04-01

    CRIBFLEX is a novel approach to mid-altitude observational particle physics intended to correlate the phenomena of semiconductor bit-flipping with cosmic ray activity. Here a weather balloon carries a Geiger counter and DRAM memory to various altitudes; the data collected will contribute to the development of memory device protection. We present current progress toward initial flight and data acquisition. This work is supported by the Society of Physics Students with funding from a Chapter Research Award.

  3. Rigidity Dependence of Cosmic Ray Modulation

    NASA Astrophysics Data System (ADS)

    Agarwal Mishra, Rekha; Mishra, Rajesh Kumar

    2012-07-01

    The various observed harmonics of the cosmic ray variation may be understood on a unified basis if the free space cosmic ray anisotropy is non-sinusoidal in form. The major objective of this paper is to study the first three harmonics of cosmic ray intensity on geo-magnetically quiet days over the period 1965-1990 for Deep River, Goose Bay and Tokyo neutron monitoring stations. The amplitude of first harmonic remains high for Deep River having low cutoff rigidity as compared to Tokyo neutron monitor having high cutoff rigidity on quiet days. The diurnal amplitude significantly decreases in 1987 at Deep River and in 1986 at Tokyo during solar activity minimum years. The diurnal time of maximum significantly shifts to an earlier time as compared to the corotational direction at both the stations having different cutoff rigidities. The time of maximum for first harmonic significantly shifts towards later hours and for second harmonic it shifts towards earlier hours at low cutoff rigidity station i.e. Deep River as compared to the high cut off rigidity station i.e. Tokyo on quiet days. The amplitude of second/third harmonics shows a good positive correlation with solar wind velocity, while the others (i.e. amplitude and phase) have no significant correlation on quiet days. The solar wind velocity significantly remains in the range 350 to 425 km/s i.e. being nearly average on quiet days. The amplitude and direction of the anisotropy on quiet days are weakly dependent on high-speed solar wind streams for these neutron monitoring stations of low and high cutoff rigidity threshold. Keywords: cosmic ray, cut off rigidity, quiet days, harmonics.

  4. Cosmic ray gradients in the outer heliosphere

    NASA Technical Reports Server (NTRS)

    Fillius, W.; Wake, B.; Ip, W.-H.; Axford, I.

    1983-01-01

    Launched in 1972 and 1973 respectively, the Pioneer 10 and 11 spacecraft are now probing the outer heliosphere on their final escape from the sun. The data in this paper extend for almost an entire solar cycle from launch to early 1983, when Pioneer 10 was at a heliocentric distance of 29 AU and Pioneer 11, 13 AU. The UCSD instruments on board were used to study the gradient, and to look at the time and spatial variations of the cosmic ray intensities.

  5. The highest energy cosmic rays: Observations

    NASA Astrophysics Data System (ADS)

    Sommers, Paul

    2013-02-01

    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.

  6. Sources of the ultraheavy cosmic rays

    NASA Technical Reports Server (NTRS)

    Margolis, S. H.; Blake, J. B.

    1985-01-01

    The suggestions that the source abundances of cosmic ray nuclei heavier then Fe differ significantly from Solar System abundances are not well supported by the data without assuming preferential acceleration. The Solar System abundances of Pb and Bi are split into r-, standard s-, and cyclic 8-process components; the apprarent deficiency of Pb seen in the HEAO-3 Heavy Nuclei Experiment data might indicate an absence of Pb from the recycling 8-process.

  7. Fluorescence Detection of Cosmic Ray Air Showers Between 1016.5 and 1018.5 eV with the Telescope Array Low Energy Extension (TALE)

    NASA Astrophysics Data System (ADS)

    Zundel, Zachary

    The Telescope Array (TA) Collaboration has completed construction of a low-energy extension to its Middle Drum telescope station. Ten new telescopes were added observing 32-59 degrees in elevation above the original telescopes. A graded array of scintillator detectors (SDs) with spacings of 400-600-1200 m is being installed in front of the telescope station. With these upgrades, the physics threshold will be lowered below 1016.5 eV. The TA Low Energy Extension (TALE) will explore the regime corresponding to the LHC center-of-mass energy. This is also the region where the transition from galactic to extra-galactic cosmic ray flux is suspected to occur. A brief overview of the physics is presented as well as a report on the progress toward measuring the cosmic ray spectrum between 1016.5 and 1018.5 eV.

  8. Cosmic X-ray physics

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

    The soft X-ray sky survey data are combined with the results from the UXT sounding rocket payload. Very strong constraints can then be placed on models of the origin of the soft diffuse background. Additional observational constraints force more complicated and realistic models. Significant progress was made in the extraction of more detailed spectral information from the UXT data set. Work was begun on a second generation proportional counter response model. The first flight of the sounding rocket will have a collimator to study the diffuse background.

  9. Erich Regener - a forgotten cosmic ray pioneer

    NASA Astrophysics Data System (ADS)

    Carlson, Per; Watson, Alan

    2013-04-01

    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.

  10. Ultra high-energy cosmic ray observations

    NASA Astrophysics Data System (ADS)

    Kampert, K.-H.

    2008-07-01

    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 Mérida, 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.

  11. Elemental technetium as a cosmic-ray clock

    NASA Technical Reports Server (NTRS)

    Drach, J.; Salamon, M. H.

    1985-01-01

    Several radioactive isotopes have been proposed as clocks for the study of the mean cosmic ray confinement time, T sub e. Measurements of Be-10 and Al-26 give a value for T sub e of about 10 Myr when one uses a leaky box cosmic ray propagation model. It is important to obtain additional measurements of T sub e from other radioactive isotopes in order to check whether the confinement is the same throughout the periodic table. The possible use of Tc (Z = 43) as a cosmic clock is investigated. Since all isotopes of Tc are radioactive, one might be able to group these isotopes and use the elemental abundance as a whole. The results of the calculations are somewhat inconclusive for two reasons. First, the beta + decay half lives of two of the Tc isotopes relevant to our calculation are not known. Second, the dependence of the Tc abundance on the mean confinement time is rather weak when one considers the number of events expected in 4 trays of plastic track detectors. However, a future, finite measurement of the Beta + half lives and the possible use of the entire collecting area of the HNC to detect Tc nuclei could make the use of Tc as a cosmic ray clock more attractive.

  12. Cosmic movement detection using image processing

    NASA Astrophysics Data System (ADS)

    Dhage, Sudhir N.; Mishra, Akassh A.; Patil, Rajesh

    2011-10-01

    Cosmic Movement Detection is concerned with the difficult task of taking the images of sky through high powered telescope or satellite transmitted images and performing image processing in order to discover new galaxies, stars and other cosmic objects or to describe already known galaxies, stars and other cosmic objects. Description meant to describe the type of cosmic object under consideration, whether it's already been recognized previously or not, whether it's moving close to Earth or moving away from Earth. It has several applications astrophysics, astronomy and astroscience. Automating this process to a computer requires the use of various image processing techniques. The method which the present paper describes is based on Doppler Effect of light i.e. red and blue shifting property. Several factors like poor illumination, noise disturbance, viewpoint-dependence, Climate factors, Transmission and Imaging conditions can affect the algorithm working. This paper reports an algorithm for Cosmic Movement Detection using image processing and Doppler Effect of light. The present paper suggests Cosmic Movement can be detected checking the color of the galaxy and it can help in determining whether it's moving towards Earth or its moving away.

  13. Acceleration of cosmic rays in Tycho's SNR.

    NASA Astrophysics Data System (ADS)

    Morlino, G.; Caprioli, D.

    We apply the non-linear diffusive shock acceleration theory in order to describe the properties of SN 1572 (G120.1+1.4, hereafter simply Tycho). By analyzing its multi-wavelength spectrum, we show how Tycho's forward shock (FS) is accelerating protons up to ˜ 500 TeV, channeling into cosmic rays more than 10 per cent of its kinetic energy. We find that the streaming instability induced by cosmic rays is consistent with all the observational evidences indicating a very efficient magnetic field amplification (up to ˜ 300 mu G), in particular the X-ray morphology of the remnant. We are able to explain the gamma-ray spectrum from the GeV up to the TeV band, recently measured respectively by Fermi-LAT and VERITAS, as due to pion decay produced in nuclear collisions by accelerated nuclei scattering against the background gas. We also show that emission due to the accelerated electrons does not play a relevant role in the observed gamma-ray spectrum.

  14. Cosmic Ray Positrons from Pulsars

    NASA Technical Reports Server (NTRS)

    Harding, Alice K.

    2010-01-01

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

  15. FAMOUS - A prototype silicon photomultiplier telescope for the fluorescence detection of ultra-high-energy cosmic rays

    NASA Astrophysics Data System (ADS)

    Stephan, Maurice; Assis, Pedro; Brogueira, Pedro; Ferreira, Miguel; Hebbeker, Thomas; Lauscher, Markus; Mendes, Luís; Meurer, Christine; Middendorf, Lukas; Pimenta, Mário; Schumacher, Johannes

    2013-06-01

    Due to their high photon detection efficiency, silicon photomultipliers (SiPMs) promise to increase the sensitivity of today's fluorescence telescopes which use photomultiplier tubes to detect light originating from extensive air showers. On the other hand, drawbacks like a small sensitive area, a strong temperature dependence, a high noise rate and a reduced dynamic range have to be managed. We present plans for FAMOUS, a prototype fluorescence telescope using SiPMs and a special light collecting optical system of Winston cones to increase the sensitive area. The prototype will make use of a Fresnel lens. For several different types of SiPMs we measured their characteristics. Moreover, we will present the R&D in compact modular electronics using photon counting techniques. An evaluation of the performance of the optical telescope design is performed by means of a full detector simulation.

  16. Measurements of the cosmic-ray Be/B ratio and the age of cosmic rays

    NASA Technical Reports Server (NTRS)

    Brown, J. W.; Stone, E. C.; Vogt, R. E.

    1974-01-01

    The ratio Be/B depends on whether the confinement time of cosmic rays in the Galaxy is long or short compared to the radioactive half-life of Be-10. We report observations of this ratio which were obtained with a dE/dx-Cerenkov detector launched into a polar orbit on OGO-6 as part of the Caltech Solar and Galactic Cosmic Ray Experiment. Be/B ratios were determined for various rigidity thresholds up to 15 GV. We find no statistically significant rigidity dependence of the ratio, which is 0.41 plus or minus 0.02 when averaged over all observed cutoffs. Additional calculations suggest that if the present fragmentation parameters are correct, then the lifetime of cosmic rays in the Galaxy is less then 10 m.y.

  17. Cosmic Ray and Tev Gamma Ray Generation by Quasar Remnants

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

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

  18. The intergalactic propagation of ultrahigh energy cosmic ray nuclei

    SciTech Connect

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

    2006-08-01

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

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

    SciTech Connect

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

    2007-05-08

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

  20. Novel approach to imaging by cosmic-ray muons

    NASA Astrophysics Data System (ADS)

    Bikit, Istvan; Mrdja, Dusan; Bikit, Kristina; Slivka, Jaroslav; Jovancevic, Nikola; Oláh, László; Hamar, Gergő; Varga, Dezső

    2016-03-01

    Cosmic-ray muons can be used for imaging of large structures, or high-density objects with high atomic number. The first task can be performed by measurement of muon absorption within very thick material layers, while the second approach is based on muon multiple scattering. However, the muon imaging of small structures with low atomic number and density was not yet solved appropriately. Here we show the first results of cosmic-ray muon imaging of small objects made of elements of low atomic number. This novel approach includes detection of secondary particles produced by muons, which were not used at all in previous muon imaging methods. Thus, the list of elements, as well as the range of dimensions of objects which can be imaged are significantly expanded.

  1. Ultrahigh-energy Cosmic Rays and Black Hole Mergers

    NASA Astrophysics Data System (ADS)

    Kotera, Kumiko; Silk, Joseph

    2016-06-01

    The recent detection of the gravitational-wave source GW150914 by the LIGO collaboration motivates a speculative source for the origin of ultrahigh-energy cosmic rays as a possible byproduct of the immense energies achieved in black hole (BH) mergers, provided that the BHs have spin, as seems inevitable, and there are relic magnetic fields and disk debris remaining from the formation of the BHs or from their accretion history. We argue that given the modest efficiency \\lt 0.01 required per event per unit of gravitational-wave energy release, merging BHs potentially provide an environment for accelerating cosmic rays to ultrahigh energies. The presence of tidally disrupted planetary or asteroidal debris could lead to associated fast radio bursts.

  2. KCDC — The KASCADE Cosmic-ray Data Centre

    NASA Astrophysics Data System (ADS)

    Haungs, A.; Blumer, J.; Fuchs, B.; Kang, D.; Schoo, S.; Wochele, D.; Wochele, J.; Apel, W. D.; Arteaga-Velázquez, J. C.; Bekk, K.; Bertaina, M.; Bozdog, H.; Brancus, I. M.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Fuhrmann, D.; Gherghel-Lascu, A.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Heck, D.; Hörandel, J. R.; Huber, D.; Huege, T.; Kampert, K. H.; Klages, H. O.; Link, K.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Oehlschläger, J.; Ostapchenko, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Zabierowski, J.

    2015-08-01

    KCDC, the ‘KASCADE Cosmic-ray Data Centre’, is a web portal, where data of astroparticle physics experiments will be made available for the interested public. The KASCADE experiment, financed by public money, was a large-area detector for the measurement of high-energy cosmic rays via the detection of air showers. KASCADE and its extension KASCADE-Grande stopped finally the active data acquisition of all its components including the radio EAS experiment LOPES end of 2012 after more than 20 years of data taking. In a first release, with KCDC we provide to the public the measured and reconstructed parameters of more than 160 million air showers. In addition, KCDC provides the conceptional design, how the data can be treated and processed so that they are also usable outside the community of experts in the research field. Detailed educational examples make a use also possible for high-school students and early stage researchers.

  3. The Cosmic ?-ray Background from supernovae

    NASA Astrophysics Data System (ADS)

    Watanabe, K.; Hartmann, D. H.; Leising, M. D.; The, L.-S.; Share, G. H.; Kinzer, R. L.

    1997-05-01

    The Cosmic ?-ray Background (CGB) near photon energies E?~1 MeV may be partly, or even completely, due to ?-ray production in supernovae. In particular, ?-ray line emission from the decay chain 56Ni-->56Co-->56Fe (847, 1238, 1770, 2599, 2030, 3250 keV) is the dominant source for the SN-induced CGB. Although iron synthesis occurs in all types of supernovae, SNIa contribute predominantly to the background mostly due to higher photon escape probabilities. Estimates of the global star formation history in the local universe yield a present-day rate density of ~=3.710-2 h3 Msolar Mpc-3 yr-1, but the star formation rate was about ten times higher at a redshift of order unity. The rate then decreases again, reaching the present-day value near redshifts ~=5. In addition to ?-rays from SNIa we also consider contributions to the CGB due to lines from SNII (such as 26Al at 1.8 MeV, 44Ti at 1.157 MeV, and 60Co at 1.17 & 1.33 MeV). The ?-ray spectrum of Model W10HMM (Pinto & Woosley [8]) was time integrated to derive a template spectrum for Type II supernovae. For SNIa we also included the ?-ray continuum, using the W7 model (Nomoto et al. [5]), integrated over 600 days, as template. We discuss the various contributions of supernovae to the CGB, and emphasize the value of ?-ray observations in the MeV range as a potential tool for studies of cosmic chemical evolution.

  4. Pierre Auger Enhancements: Transition from Galactic to Extragalactic Cosmic Ray Sources

    SciTech Connect

    Etchegoyen, A.; Melo, D.; Supanitsky, A. D.; Medina, M. C.

    2007-06-19

    The Pierre Auger Collaboration has decided to include detector enhancements in order to have unitary detection efficiencies down to 1017 eV in cosmic rays detection. These enhancements consist in high elevation telescopes and an infill area with both surface detectors and underground muon counters thus allowing a detailed study of the spectrum region where the cosmic rays sources are assumed to change from galactic to extragalactic origins.

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

    SciTech Connect

    Gelfand, Joseph D.; Castro, Daniel; Slane, Patrick O.; Temim, Tea; Hughes, John P.; Rakowski, Cara E-mail: cara.rakowski@gmail.com

    2013-11-10

    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 γ-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.

  6. Cosmic Ray Helium Intensities over the Solar Cycle from ACE

    NASA Technical Reports Server (NTRS)

    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

    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.

  7. Muon acceleration in cosmic-ray sources

    SciTech Connect

    Klein, Spencer R.; Mikkelsen, Rune E.; Becker Tjus, Julia

    2013-12-20

    Many models of ultra-high energy cosmic-ray production involve acceleration in linear accelerators located in gamma-ray bursts, magnetars, or other sources. These transient sources have short lifetimes, which necessitate very high accelerating gradients, up to 10{sup 13} keV cm{sup –1}. At gradients above 1.6 keV cm{sup –1}, muons produced by hadronic interactions undergo significant acceleration before they decay. This muon acceleration hardens the neutrino energy spectrum and greatly increases the high-energy neutrino flux. Using the IceCube high-energy diffuse neutrino flux limits, we set two-dimensional limits on the source opacity and matter density, as a function of accelerating gradient. These limits put strong constraints on different models of particle acceleration, particularly those based on plasma wake-field acceleration, and limit models for sources like gamma-ray bursts and magnetars.

  8. Gamma-ray bursters as sources of cosmic rays

    NASA Astrophysics Data System (ADS)

    Milgrom, Mordehai; Usov, Vladimir

    1996-04-01

    From the little we know of the physical conditions in ?-ray bursters, it seems that they are potentially effective in the acceleration of high-energy cosmic rays (CRs), especially if the bursters are at cosmological distances. We find that, with the observed statistics and fluxes of ?-ray bursts, cosmological bursters may be an important source of cosmic rays in two regions of the observed spectrum: (1) At the very-high-energy end ( E > 10 19 eV), where CRs must be of extragalactic origin. (2) Around and above the spectral feature that has been described as a bump and/or a knee, which occurs around 10 15 eV. The occasional bursters that occur inside the Galaxy about once in a few hundred thousand years if burst emission is isotropic; more often, if it is beamed could maintain the density of galactic cosmic rays at the observed level in this range. These two energy ranges might correspond to two typical CR energy scales characteristic of bursters: one pertinent to CR acceleration due to interaction of a magnetized-fireball front with an ambient medium; the other to acceleration in the fireball itself (e.g. shock acceleration).

  9. The isotopic composition of cosmic-ray calcium

    NASA Technical Reports Server (NTRS)

    Wiedenbeck, M. E.; George, J. S.; Binns, W. R.; Christian, E. R.; Cummings, A. C.; Davis, A. J.; Israel, M. H.; Leske, R. A.; Mewaldt, R. A.; Stone, E. C.; Rosenvinge, T. T. von

    2001-01-01

    We find that the relative abundance of cosmic ray calcium isotopes in the cosmic-ray source are very similar to those found in solar-system material, in spite of the fact that different types of stars are thought to be responsible for producing these two isotopes. This observation is consistent with the view that cosmic rays are derived from a mixed sample of interstellar matter.

  10. Cosmic-ray variations and the interplanetary sector structures.

    NASA Technical Reports Server (NTRS)

    Yoshida, S.; Akasofu, S.; Ogita, N.

    1971-01-01

    Fifteen passages of interplanetary sector structures that occurred between December 1967 and June 1968 are examined. A spherical harmonic analysis of cosmic ray intensity is performed to obtain cosmic ray intensity variations as a function of asymptotic latitude, longitude, and universal time. A clear north-south asymmetry of cosmic ray intensity, which depends on the sign of the interplanetary sector magnetic fields, is revealed.

  11. The ATLAS trigger - commissioning with cosmic rays

    NASA Astrophysics Data System (ADS)

    Boyd, J.

    2008-07-01

    The ATLAS detector at CERN's LHC will be exposed to proton-proton collisions from beams crossing at 40 MHz. At the design luminosity there are roughly 23 collisions per bunch crossing. ATLAS has designed a three-level trigger system to select potentially interesting events. The first-level trigger, implemented in custom-built electronics, reduces the incoming rate to less than 100 kHz with a total latency of less than 2.5μs. The next two trigger levels run in software on commercial PC farms. They reduce the output rate to 100-200 Hz. In preparation for collision data-taking which is scheduled to commence in May 2008, several cosmic-ray commissioning runs have been performed. Among the first sub-detectors available for commissioning runs are parts of the barrel muon detector including the RPC detectors that are used in the first-level trigger. Data have been taken with a full slice of the muon trigger and readout chain, from the detectors in one sector of the RPC system, to the second-level trigger algorithms and the data-acquisition system. The system is being prepared to include the inner-tracking detector in the readout and second-level trigger. We will present the status and results of these cosmic-ray based commissioning activities. This work will prove to be invaluable not only during the commissioning phase but also for cosmic-ray data-taking during the normal running for detector performance studies.

  12. Origin and propagation of galactic cosmic rays

    NASA Technical Reports Server (NTRS)

    Cesarsky, Catherine J.; Ormes, Jonathan F.

    1987-01-01

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

  13. Supernova--remnant origin of cosmic rays?

    PubMed

    Butt, Yousaf M; Torres, Diego F; Romero, Gustavo E; Dame, Thomas M; Combi, Jorge A

    2002-08-01

    It is thought that Galactic cosmic-ray nuclei are gradually accelerated to high energies (up to about 300 TeV per nucleon, where 1 TeV is 10(12) eV) in the expanding shock waves connected with the remnants of powerful supernova explosions. However, this conjecture has eluded direct observational confirmation since it was first proposed in 1953 (ref. 3). Enomoto et al. claim to have finally found definitive evidence that corroborates this model, proposing that very-high-energy, TeV-range, gamma-rays from the supernova remnant (SNR) RX J1713.7-3946 are due to the interactions of energetic nuclei in this region. Here we argue that their claim is not supported by the existing multiwavelength spectrum of this source. The search for the origin(s) of Galactic cosmic-ray nuclei may be closing in on the long-suspected supernova-remnant sources, but it is not yet over. PMID:12152068

  14. Radiation Hazard from Galactic Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Farahat, Ashraf

    2006-03-01

    Space radiation is a major hazard to astronauts in long-duration human space explosion. Astronauts are exposed to an enormous amount of radiation during their missions away from the Earth in outer space. Deep space is a rich environment of protons, gamma rays and cosmic rays. A healthy 40 years old man staying on Earth away from large doses of radiation stands a 20% chance of dying from cancer. If the same person travels into a 3- year Mars mission, the added risk should increase by 19%. This indicates that there is 39% chance of having cancer after he comes back to Earth. Female astronaut chances to get cancer is even almost double the above percentage. The greatest threat to astronauts en route to the red planet is galactic cosmic rays (GCR). GCRs penetrate through the skin of spaceships and people like tiny firearm bullets, breaking the strands of DNA molecules, damaging genes, and killing cells. Understanding the nature of the GCRs, their effect on biological cells, and their interactions with different shielding materials is the key point to shield against them in long space missions. In this paper we will present a model to evaluate the biological effects of GCRs and suggestion different ways to shield against them.

  15. A model for the proton spectrum and cosmic ray anisotropy

    NASA Technical Reports Server (NTRS)

    Xu, C.

    1985-01-01

    The problem of the origin of the cosmic rays is still uncertain. As a theory, it should explain the support of particles and energy, the mechanism of acceleration and propagation as well as some important features obtained directly from cosmic ray experiments, such as the power spectrum and the knee. There are two kinds of models for interpreting the knee of the cosmic ray spectrum. One is the leaky box model. Another model suggests that the cut-off rigidity of the main sources causes the knee. The present paper studies the spectrum and the anisotropy of cosmic rays in an isotropic diffuse model with explosive discrete sources in an infinite galaxy.

  16. Acoustic instability driven by cosmic-ray streaming

    NASA Astrophysics Data System (ADS)

    Begelman, Mitchell C.; Zweibel, Ellen G.

    1994-08-01

    We study the linear stability of compressional waves in a medium through which cosmic rays stream at the Alfven speed due to strong coupling with Alfven waves. Acoustic waves can be driven unstable by the cosmic-ray drift, provided that the streaming speed is sufficiently large compared to the thermal sound speed. Two effects can cause instability: (1) the heating of the thermal gas due to the damping of Alfven waves driven unstable by cosmic-ray streaming; and (2) phase shifts in the cosmic-ray pressure perturbation caused by the combination of cosmic-ray streaming and diffusion. The instability does not depend on the magnitude of the background cosmic-ray pressure gradient, and occurs whether or not cosmic-ray diffusion is important relative to streaming. When the cosmic-ray pressure is small compared to the gas pressure, or cosmic-ray diffusion is strong, the instability manifests itself as a weak overstability of slow magnetosonic waves. Larger cosmic-ray pressure gives rise to new hybrid modes, which can be strongly unstable in the limits of both weak and strong cosmic-ray diffusion and in the presence of thermal conduction. Parts of our analysis parallel earlier work by McKenzie & Webb (which were brought to our attention after this paper was accepted for publication), but our treatment of diffusive effects, thermal conduction, and nonlinearities represent significant extensions. Although the linear growth rate of instability is independent of the background cosmic-ray pressure gradient, the onset of nonlinear eff ects does depend on absolute value of DEL (vector differential operator) Pc. At the onset of nonlinearity the fractional amplitude of cosmic-ray pressure perturbations is delta PC/PC approximately (kL) -1 much less than 1, where k is the wavenumber and L is the pressure scale height of the unperturbed cosmic rays. We speculate that the instability may lead to a mode of cosmic-ray transport in which plateaus of uniform cosmic-ray pressure are separated by either laminar or turbulent jumps in which the thermal gas is subject to intense heating.

  17. Isotopic composition of cosmic-ray boron and nitrogen

    NASA Technical Reports Server (NTRS)

    Krombel, K. E.; Wiedenbeck, M. E.

    1988-01-01

    New measurements of the cosmic-ray boron and nitrogen isotopes at earth and of the elemental abundances of boron, carbon, nitrogen, and oxygen are presented. A region of mutually allowed values for the cosmic-ray nitrogen source ratios is determined, and the cosmic-ray escape mean free path is determined as a function of energy using a leaky box model for cosmic-ray propagation in the Galaxy. Relative to O-16, a N-15 source abundance consistent with solar system composition and a N-14 source abundance which is a factor of about three underabundant relative to the solar value are found.

  18. Cosmic-ray record in solar system matter

    SciTech Connect

    Reedy, R.C.; Arnold, J.R.; Lal, D.

    1983-01-14

    The energetic nuclei in cosmic rays interact with meteoroids, the moon, planets, and other solar system matter. The nucleides and heavy nuclei tracks produced by the cosmic-ray particles in these targets contain a wealth of information about the history of the objects and temporal ans spatial variations in the particle fluxes. Most lunar samples and many meteorites ahve complex histories of cosmic-ray exposure from erosion, gardening, fragmentation, orbital changes, and other processes. There appear to be variations in the past fluxes of solar particles, and possibly also galactic cosmic rays, on time scales of 10/sup 4/ to 10/sup 7/ years.

  19. Acoustic instability driven by cosmic-ray streaming

    NASA Technical Reports Server (NTRS)

    Begelman, Mitchell C.; Zweibel, Ellen G.

    1994-01-01

    We study the linear stability of compressional waves in a medium through which cosmic rays stream at the Alfven speed due to strong coupling with Alfven waves. Acoustic waves can be driven unstable by the cosmic-ray drift, provided that the streaming speed is sufficiently large compared to the thermal sound speed. Two effects can cause instability: (1) the heating of the thermal gas due to the damping of Alfven waves driven unstable by cosmic-ray streaming; and (2) phase shifts in the cosmic-ray pressure perturbation caused by the combination of cosmic-ray streaming and diffusion. The instability does not depend on the magnitude of the background cosmic-ray pressure gradient, and occurs whether or not cosmic-ray diffusion is important relative to streaming. When the cosmic-ray pressure is small compared to the gas pressure, or cosmic-ray diffusion is strong, the instability manifests itself as a weak overstability of slow magnetosonic waves. Larger cosmic-ray pressure gives rise to new hybrid modes, which can be strongly unstable in the limits of both weak and strong cosmic-ray diffusion and in the presence of thermal conduction. Parts of our analysis parallel earlier work by McKenzie & Webb (which were brought to our attention after this paper was accepted for publication), but our treatment of diffusive effects, thermal conduction, and nonlinearities represent significant extensions. Although the linear growth rate of instability is independent of the background cosmic-ray pressure gradient, the onset of nonlinear eff ects does depend on absolute value of DEL (vector differential operator) P(sub c). At the onset of nonlinearity the fractional amplitude of cosmic-ray pressure perturbations is delta P(sub C)/P(sub C) approximately (kL) (exp -1) much less than 1, where k is the wavenumber and L is the pressure scale height of the unperturbed cosmic rays. We speculate that the instability may lead to a mode of cosmic-ray transport in which plateaus of uniform cosmic-ray pressure are separated by either laminar or turbulent jumps in which the thermal gas is subject to intense heating.

  20. A cosmic-ray-mediated shock in the solar system

    NASA Technical Reports Server (NTRS)

    Eichler, D.

    1981-01-01

    It is pointed out that the flare-induced blast wave of Aug. 4, 1972, the most violent disturbance in the solar wind on record, produced cosmic rays with an efficiency of about 50%. Such a high efficiency is predicted by the self-regulating production model of cosmic-ray origin in shocks. Most interplanetary shocks, according to simple theoretical analysis, are not strong enough to produce cosmic rays efficiently. However, if shock strength is the key parameter governing efficiency, as present interplanetary data suggest, then shocks from supernova blasts, quasar outbursts, and other violent astrophysical phenomena should be extremely efficient sources of cosmic rays.

  1. High energy cosmic ray iron spectrum experiment

    NASA Technical Reports Server (NTRS)

    Arens, J. F.; Balasubrahmanyan, V. K.; Ormes, J. F.; Schmidt, W. K. H.; Simon, M.; Spiegelhauer, H.

    1978-01-01

    An instrument containing a gas Cerenkov counter and an iron ionization spectrometer was constructed in order to measure the cosmic-ray iron spectrum to 300 GeV/nucleon. Trajectories of particles were determined by entopistic or position-determining scintillator systems. The geometric factors with and without the gas Cerenkov counter were 0.3 and 0.6 sq m-ster, respectively. The instrument was successfully flown in June 1976 without the spectrometer and in October 1976 with the spectrometer from Palestine, Texas. The June flight yielded 14.5 h of data; the October flight, 25 h.

  2. Acceleration and propagation of solar cosmic rays

    NASA Astrophysics Data System (ADS)

    Podgorny, I. M.; Podgorny, A. I.

    2015-12-01

    Analysis of the solar cosmic ray measurements on the Geostationary Orbital Environmental Satellite (GOES) spacecraft indicated that the duration of solar flare relativistic proton large pulses is comparable with the solar wind propagation duration from the Sun to the Earth. The front of the proton flux from flares on the western solar disk approaches the Earth with a flight time along the Archimedean spiral magnetic field line of 15-20 min. The proton flux from eastern flares is registered in the Earth's orbit 3-5 h after the flare onset. These particles apparently propagate across IMF owing to diffusion.

  3. Turbulent heating in solar cosmic ray theory

    NASA Technical Reports Server (NTRS)

    Weatherall, J.

    1983-01-01

    The heating of minor ions in solar flares by wave-wave-particle interaction with Langmuir waves, or ion acoustic waves, can be described by a diffusion equation in velocity-space for the particle distribution function. The dependence of the heating on the ion charge and mass, and on the composition of the plasma, is examined in detail. It is found that the heating mechanisms proposed by Ibragimov and Kocharov cannot account for the enhanced abundances of heavy elements in the solar cosmic rays.

  4. Cosmic Ray Induced Bit-Flipping Experiment

    NASA Astrophysics Data System (ADS)

    Callaghan, Edward; Parsons, Matthew

    2015-04-01

    CRIBFLEX is a novel approach to mid-altitude observational particle physics intended to correlate the phenomena of semiconductor bit-flipping with cosmic ray activity. Here a weather balloon carries a Geiger counter and DRAM memory to various altitudes; the data collected will contribute to the development of memory device protection. We present current progress toward initial flight and data acquisition. This work is supported by the Society of Physics Students with funding from a Chapter Research Award. Supported by a Society of Physics Students Chapter Research Award.

  5. Correlation between cosmic rays and ozone depletion.

    PubMed

    Lu, Q-B

    2009-03-20

    This Letter reports reliable satellite data in the period of 1980-2007 covering two full 11-yr cosmic ray (CR) cycles, clearly showing the correlation between CRs and ozone depletion, especially the polar ozone loss (hole) over Antarctica. The results provide strong evidence of the physical mechanism that the CR-driven electron-induced reaction of halogenated molecules plays the dominant role in causing the ozone hole. Moreover, this mechanism predicts one of the severest ozone losses in 2008-2009 and probably another large hole around 2019-2020, according to the 11-yr CR cycle. PMID:19392251

  6. Galactic origin of cosmic rays I

    SciTech Connect

    Colgate, S.A.

    1981-01-01

    The theoretical basis for the supernova envelope shock origin of cosmic rays is reviewed. The theoretical explanation of the SN Type I light curve requires the ejection of a relativistic mass fraction. The criterion of the adiabatic decelleration by Alfven wave trapping neither applies in theory, when ..beta.. > 1, or practice, the Starfish high altitude nuclear explosion experiment. Arguments of delayed acceleration due to K-capture are not applicable to SN ejecta because a period of prompt recombination exists before subsequent stripping in propagation.

  7. 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.

  8. 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)

    Sagdeev, Roald

    1995-01-01

    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.

  9. Identification of Sources of Ultrahigh Energy Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Uryson, A. V.

    2001-08-01

    The arrival directions of extensive air showers with energies 4×1019detected by the AGASA, Yakutsk, Haverah Park, and Fly’s Eye arrays are analyzed in order to identify possible sources of cosmic rays with these energies. We searched for active galactic nuclei, radio galaxies, and X-ray pulsars within 3-error boxes around the shower-arrival directions and calculated the probabilities of objects being in the 3 error boxes by chance. These probabilities are small in the case of Seyfert galaxies with redshifts z<0.01 and BL Lac objects, corresponding to P>3σ (σ is the parameter of Gaussian distribution). The Seyfert galaxies are characterized by moderate luminosities (L<1046 erg/s) and weak radio and X-ray emission. We also analyzed gamma-ray emission at energies E>1014 eV recorded by the Bolivian and Tian Shan arrays. The source identifications suggest that the gamma rays could have been produced in interactions of cosmic rays with the microwave background radiation and subsequent electromagnetic cascades in intergalactic space. We estimate the strength of intergalactic magnetic fields outside galaxy clusters to be B≤8.7×10-10 G.

  10. Gamma-rays, cosmic rays, and galactic structure

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1976-01-01

    The relation of SAS-2 observations of galactic gamma-rays to the large scale distribution of cosmic rays and interstellar gas in the galaxy is reviewed. Starting with a discussion of production rates, the case for pion decay being the predominant production mechanism in the galactic disk above 100 MeV is reestablished, and it is also pointed out that Compton gamma-rays can be a significant source near l = 0. The concepts of four distinct galactic regions are defined, viz. the nebulodisk, ectodisk, radiodisk and exodisk. Bremsstrahlung and pion decay gamma-rays are associated with the first two (primarily the first) regions, and Compton gamma-rays and synchrotron radiation are associated with the latter two regions. On a large scale, the cosmic rays, interstellar gas (primarily H2 clouds in the inner galaxy) and gamma-ray emissivity all peak between 5 and 6 kpc from the galactic center. This correlation is related to correlation with other population I phenomena and is discussed in terms of the density wave concept of galactic structure.

  11. Lunar surface cosmic ray experiment S-152, Apollo 16

    NASA Technical Reports Server (NTRS)

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

    1973-01-01

    This investigation was directed at determining the energy spectra and abundances of low energy heavy cosmic rays (0.03 E or = 150 MeV/nucleon). The cosmic rays were detected using plastic and glass particle track detectors. Particles emitted during the 17 April 1972 solar flare dominated the spectra for energies below about 70 MeV/nucleon. Two conclusions emerge from the low energy data: (1) The differential energy spectra for solar particles vary rapidly for energies as low as 0.05 MeV/nucleon for iron-group nuclei. (2) The abundance ratio of heavy elements changes with energy at low energies; heavy elements are enhanced relative to higher elements increasingly as the energy decreases. Galactic particle fluxes recorded within the spacecraft are in agreement with those predicted taking into account solar modulation and spacecraft shielding. The composition of the nuclei at energies above 70 MeV/nucleon imply that these particles originate outside the solar system and hence are galactic cosmic rays.

  12. Ultra-High Energy Cosmic Rays: A Recap of the Discussions at the European Cosmic Ray Symposium 2014

    NASA Astrophysics Data System (ADS)

    Haungs, Andreas

    2015-08-01

    This contribution summarizes the talks, posters, and discussions of the ECRS 2014, held in Kiel, Germany - related to the research field of ultra-high energy cosmic rays (UHECR). Here, the definition of UHECR is cosmic rays with an energy above approximately 0.1 EeV, i.e. 1017 eV, and the corresponding sessions were named HECR-II. Recent experimental results, like the identified heavy knee in the cosmic ray energy spectrum or the hotspot in the arrival direction of cosmic rays with highest energy, will be shown and discussed in relation to the need and requirements of future experimental efforts.

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

    SciTech Connect

    Langeveld, Willy G.J.

    2003-08-25

    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.

  14. REal-time COsmic Ray Database (RECORD)

    NASA Astrophysics Data System (ADS)

    Usoskin, I.; Kozlov, Valery; Ksenofontov, Leonid, Kudela, Karel; Starodubtsev, Sergei; Turpanov, Alexey; Yanke, Victor

    2003-07-01

    In this paper we present a first distributed REal-time COsmic Ray Database (RECORD). The aim of the project is to develop a unified database with data from different neutron monitors collected together, in unified format and to provide a user with several commonly used data access methods. The database contains not only original cosmic ray data but also auxiliary data necessary for scientific data analysis. Currently the database includes Lomn.Stit, Moscow, Oulu; Tixie Bay, Yakutsk stations. The main database server is located in IKFIA SB RAS (Yakutsk) but there will be several mirrors of the database. The database and all its mirrors are up dated on the nearly real-time (1 hour) basis. The data access software includes WWW-interface, Perl scripts and C library, which may be linked to a user program. Most of frequently used functions are implemented to make it operable to users without SQL language knowledge. A draft of the data representation standard is suggested, based on common practice of neutron monitor community. The database engine is freely distributed open-sourced PostgreSQL server coupled with a set of replication to ols developed at Bio engineering division of the IRCCS E.Medea, Italy.

  15. High-energy cosmic ray intensity waves

    SciTech Connect

    Jacklyn, R.M.; Duldig, M.L.; Pomerantz, M.A.

    1987-08-01

    A new mode of galactic cosmic ray modulation has been observed. It manifests itself as waves of isotropic intensity variations of high-energy (--150 GeV) galactic cosmic rays. The wave periods are in synchronism with the alternating toward and away polarity states of the sectored interplanetary magnetic field. Since data with the requisite precision for observing the phenomenon first became available in 1982, isotropic intensity waves have occurred during the latter half of three successive years when the long-term modulation was maximum (1982) and recovering rapidly (1983 and 1984), but were not readily discernible in 1985, after the steady state intensity had recovered almost to the solar minimum level. The variational spectrum ..delta..j( p)/( j( p) = kp/sup ..gamma../ (where p is magnetic rigidity) is hard, with ..gamma..approx. =0. Although the largest Forbush decrease ever recorded occurred while the 1982 episode was in progress, isotropic intensity waves are not causally related to that effect. However, the isotropic intensity waves observed thus far are in phase in the southern hemisphere with much smaller concurrent variations of the north-south anisotropy. The new phenomenon bespeaks a difference, not yet identified, in the plasma regimes on opposite sides of the neutral sheet. Copyright American Geophysical Union 1987

  16. Modeling galactic cosmic rays at lunar orbit

    NASA Astrophysics Data System (ADS)

    Huang, Chia-Lin; Spence, Harlan; Kress, Brian; Shepherd, Simon

    High-energy particles such as galactic cosmic rays (GCRs) and solar energetic particles (SEPs) have sufficient kinetic energy to produce undesirable biological effects in astronauts as well as environmental effects on spacecraft electronic systems. In low Earth orbit, such radiation effects are minimized owing to the strong geomagnetic cutoff from Earth's internal magnetic field. However, the risks increase at higher altitudes wherever shielding magnetic fields are weak, including at lunar orbit. In order to prepare for future robotic and human exploration on the Moon, characterizing the lunar radiation environment is essential. Because GCRs and SEPs are charged particles with large gyroradii, their trajectories are governed by magnetic fields present on large size scales. For example, at lunar orbit, both the external interplanetary magnetic field and Earth's internally complex magnetosphere could alter the energetic particle flux. We combine an empirical magnetic field model of Earth's magnetosphere with a fullyrelativistic charged particle trajectory code to model the access of GCRs and SEPs to the lunar surface. We follow ions with energies above 10 MeV/nucleon starting from an isotropic spatial distribution in interplanetary space and calculate particle flux in the different regions of the solar wind-magnetosphere system through which the Moon orbits. Finally, we determine the extent of magnetospheric shielding at the Moon as a function of incident particle energy and lunar position. These simulation results will eventually be compared to data from NASA's Lunar Reconnaissance Orbiter "Cosmic Ray Telescope for the Effects of Radiation" instrument after its launch in late 2008.

  17. Atmospheric effects of stellar cosmic rays on Earth-like exoplanets orbiting M-dwarfs

    NASA Astrophysics Data System (ADS)

    Tabataba-Vakili, F.; Grenfell, J. L.; Grießmeier, J.-M.; Rauer, H.

    2016-01-01

    M-dwarf stars are generally considered favourable for rocky planet detection. However, such planets may be subject to extreme conditions due to possible high stellar activity. The goal of this work is to determine the potential effect of stellar cosmic rays on key atmospheric species of Earth-like planets orbiting in the habitable zone of M-dwarf stars and show corresponding changes in the planetary spectra. We build upon the cosmic rays model scheme of previous works, who considered cosmic ray induced NOx production, by adding further cosmic ray induced production mechanisms (e.g. for HOx) and introducing primary protons of a wider energy range (16 MeV-0.5 TeV). Previous studies suggested that planets in the habitable zone that are subject to strong flaring conditions have high atmospheric methane concentrations, while their ozone biosignature is completely destroyed. Our current study shows, however, that adding cosmic ray induced HOx production can cause a decrease in atmospheric methane abundance of up to 80%. Furthermore, the cosmic ray induced HOx molecules react with NOx to produce HNO3, which produces strong HNO3 signals in the theoretical spectra and reduces NOx-induced catalytic destruction of ozone so that more than 25% of the ozone column remains. Hence, an ozone signal remains visible in the theoretical spectrum (albeit with a weaker intensity) when incorporating the new cosmic ray induced NOx and HOx schemes, even for a constantly flaring M-star case. We also find that HNO3 levels may be high enough to be potentially detectable. Since ozone concentrations, which act as the key shield against harmful UV radiation, are affected by cosmic rays via NOx-induced catalytic destruction of ozone, the impact of stellar cosmic rays on surface UV fluxes is also studied.

  18. Effect of Cosmic-ray Shielding in Passive Neutron Coincidence Counting

    SciTech Connect

    Alvarez, E.; Wilkins, C.G.; Croft, S.; McElroy, R.D.; Mueller, W.F.; Philips, S.

    2006-07-01

    The minimum detectable Pu-240 effective mass for a passive neutron coincidence counter (PNCC) in a given measurement situation is ultimately set by the background neutron rate. Assuming that there is no significant source of neutron emission in the proximity of the system, the background rate is usually dominated by cosmic ray induced neutrons. In order to improve the detection limits overhead cosmic ray shielding should be considered. In this paper, we present results from an experimental assessment and calculations of the effect of overhead shielding on the cosmic ray induced neutron events. Background data were taken with a pair of active-well coincidence counters in different locations under different thicknesses and configurations of concrete to provide shielding from cosmic rays. Comparisons are made to historical performance data and to published work. These results will be useful when considering the location and shielding of PNCC systems. (authors)

  19. Ultrahigh Energy Cosmic Rays: Old Physics or New Physics?

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    2004-01-01

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

  20. Elemental composition and energy spectra of galactic cosmic rays

    NASA Technical Reports Server (NTRS)

    Mewaldt, R. A.

    1988-01-01

    A brief review is presented of the major features of the elemental composition and energy spectra of galactic cosmic rays. The requirements for phenomenological models of cosmic ray composition and energy spectra are discussed, and possible improvements to an existing model are suggested.

  1. Using the information of cosmic rays to predict influence epidemic

    NASA Astrophysics Data System (ADS)

    Yu, Z. D.

    1985-08-01

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

  2. Ninteenth International Cosmic Ray Conference. OG Sessions, Volume 2

    NASA Technical Reports Server (NTRS)

    Jones, F. C. (Compiler)

    1985-01-01

    Contributed papers addressing cosmic ray origin and galactic phenomena are compiled. Topic areas include the composition, spectra, and anisotropy of cosmic ray nuclei with energies and 1 TeV, isotopes, antiprotons and related subjects, and electrons, positrons, and measurements of synchrotron radiation.

  3. Elemental composition, isotopes, electrons and positrons in cosmic rays

    NASA Technical Reports Server (NTRS)

    Balasubrahmanyan, V. K.

    1979-01-01

    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.

  4. THE COSMIC-RAY INTENSITY NEAR THE ARCHEAN EARTH

    SciTech Connect

    Cohen, O.; Drake, J. J.; Kota, J.

    2012-11-20

    We employ three-dimensional state-of-the-art magnetohydrodynamic models of the early solar wind and heliosphere and a two-dimensional model for cosmic-ray transport to investigate the cosmic-ray spectrum and flux near the Archean Earth. We assess how sensitive the cosmic-ray spectrum is to changes in the sunspot placement and magnetic field strength, the large-scale dipole magnetic field strength, the wind ram pressure, and the Sun's rotation period. Overall, our results confirm earlier work that suggested the Archean Earth would have experienced a greatly reduced cosmic-ray flux than is the case today. The cosmic-ray reduction for the early Sun is mainly due to the shorter solar rotation period and tighter winding of the Parker spiral, and to the different surface distribution of the more active solar magnetic field. These effects lead to a global reduction of the cosmic-ray flux at 1 AU by up to two orders of magnitude or more. Variations in the sunspot magnetic field have more effect on the flux than variations in the dipole field component. The wind ram pressure affects the cosmic-ray flux through its influence on the size of the heliosphere via the pressure balance with the ambient interstellar medium. Variations in the interstellar medium pressure experienced by the solar system in orbit through the Galaxy could lead to order of magnitude changes in the cosmic-ray flux at Earth on timescales of a few million years.

  5. Charge 4/3 leptons in cosmic rays

    NASA Technical Reports Server (NTRS)

    Wada, T.; Yamashita, Y.; Imaeda, K.; Yamamoto, I.

    1985-01-01

    A cosmic ray counter telescope has been operated at zenith angles of 0, 40, 44, and 60 degs in order to look for charge 4/3 particles. A few million clean single cosmic rays of each zenith angle are analyzed.

  6. The Cosmic-Ray Intensity near the Archean Earth

    NASA Astrophysics Data System (ADS)

    Cohen, O.; Drake, J. J.; Kóta, J.

    2012-11-01

    We employ three-dimensional state-of-the-art magnetohydrodynamic models of the early solar wind and heliosphere and a two-dimensional model for cosmic-ray transport to investigate the cosmic-ray spectrum and flux near the Archean Earth. We assess how sensitive the cosmic-ray spectrum is to changes in the sunspot placement and magnetic field strength, the large-scale dipole magnetic field strength, the wind ram pressure, and the Sun's rotation period. Overall, our results confirm earlier work that suggested the Archean Earth would have experienced a greatly reduced cosmic-ray flux than is the case today. The cosmic-ray reduction for the early Sun is mainly due to the shorter solar rotation period and tighter winding of the Parker spiral, and to the different surface distribution of the more active solar magnetic field. These effects lead to a global reduction of the cosmic-ray flux at 1 AU by up to two orders of magnitude or more. Variations in the sunspot magnetic field have more effect on the flux than variations in the dipole field component. The wind ram pressure affects the cosmic-ray flux through its influence on the size of the heliosphere via the pressure balance with the ambient interstellar medium. Variations in the interstellar medium pressure experienced by the solar system in orbit through the Galaxy could lead to order of magnitude changes in the cosmic-ray flux at Earth on timescales of a few million years.

  7. Early developments: Particle physics aspects of cosmic rays

    NASA Astrophysics Data System (ADS)

    Grupen, Claus

    2014-01-01

    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 Λ's, Σ's, and Ξ'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.

  8. Ninteenth International Cosmic Ray Conference. SH Sessions, Volume 4

    NASA Technical Reports Server (NTRS)

    Jones, F. C. (Compiler)

    1985-01-01

    Papers submitted for presentation at the 19th International Cosmic Ray Conference are compiled. This volume covers solar and heliospheric phenomena, specifically, particle acceleration; cosmic ray compsotion, spectra, and anisotropy; propagation of solar and interplanetary energetic particles; solar-cycle modulation; and propagation of galactic particles in the heliosphere.

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

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

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

  10. Cosmic ray sampling of a clumpy interstellar medium

    SciTech Connect

    Boettcher, Erin; Zweibel, Ellen G.; Gallagher, J. S. III; Yoast-Hull, Tova M.

    2013-12-10

    How cosmic rays sample the multi-phase interstellar medium (ISM) in starburst galaxies has important implications for many science goals, including evaluating the cosmic ray calorimeter model for these systems, predicting their neutrino fluxes, and modeling their winds. Here, we use Monte Carlo simulations to study cosmic ray sampling of a simple, two-phase ISM under conditions similar to those of the prototypical starburst galaxy M82. The assumption that cosmic rays sample the mean density of the ISM in the starburst region is assessed over a multi-dimensional parameter space where we vary the number of molecular clouds, the galactic wind speed, the extent to which the magnetic field is tangled, and the cosmic ray injection mechanism. We evaluate the ratio of the emissivity from pion production in molecular clouds to the emissivity that would be observed if the cosmic rays sampled the mean density, and seek areas of parameter space where this ratio differs significantly from unity. The assumption that cosmic rays sample the mean density holds over much of parameter space; however, this assumption begins to break down for high cloud density, injection close to the clouds, and a very tangled magnetic field. We conclude by evaluating the extent to which our simulated starburst region behaves as a proton calorimeter and constructing the time-dependent spectrum of a burst of cosmic rays.

  11. Using the information of cosmic rays to predict influence epidemic

    NASA Technical Reports Server (NTRS)

    Yu, Z. D.

    1985-01-01

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

  12. Nineteenth International Cosmic Ray Conference. HE Sessions, Volume 7

    NASA Technical Reports Server (NTRS)

    Jones, F. C. (Compiler)

    1985-01-01

    Papers submitted for presentation at the 19th International Cosmic ray Conference are compiled. This volume contains papers which address various aspects of extensive air showers (EAS) produced by energetic particles and gamma rays.

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

    NASA Technical Reports Server (NTRS)

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

    1975-01-01

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

  14. Terrestrial Effects of High Energy Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Atri, Dimitra

    2011-01-01

    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.

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

    SciTech Connect

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

    2008-07-15

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

  16. Galactic cosmic rays on extrasolar Earth-like planets. I. Cosmic ray flux

    NASA Astrophysics Data System (ADS)

    Grießmeier, J.-M.; Tabataba-Vakili, F.; Stadelmann, A.; Grenfell, J. L.; Atri, D.

    2015-09-01

    Context. Theoretical arguments indicate that close-in terrestial exoplanets may have weak magnetic fields, especially in the case of planets more massive than Earth (super-Earths). Planetary magnetic fields, however, constitute one of the shielding layers that protect the planet against cosmic-ray particles. In particular, a weak magnetic field results in a high flux of Galactic cosmic rays that extends to the top of the planetary atmosphere. Aims: We wish to quantify the flux of Galactic cosmic rays to an exoplanetary atmosphere as a function of the particle energy and of the planetary magnetic moment. Methods: We numerically analyzed the propagation of Galactic cosmic-ray particles through planetary magnetospheres. We evaluated the efficiency of magnetospheric shielding as a function of the particle energy (in the range 16 MeV ≤ E ≤ 524 GeV) and as a function of the planetary magnetic field strength (in the range 0 M⊕ ≤ M ≤ 10 M⊕). Combined with the flux outside the planetary magnetosphere, this gives the cosmic-ray energy spectrum at the top of the planetary atmosphere as a function of the planetary magnetic moment. Results: We find that the particle flux to the planetary atmosphere can be increased by more than three orders of magnitude in the absence of a protecting magnetic field. For a weakly magnetized planet (ℳ = 0.05 ℳ⊕), only particles with energies below 512 MeV are at least partially shielded. For a planet with a magnetic moment similar to that of Earth, this limit increases to to 32 GeV, whereas for a strongly magnetized planet (ℳ = 10.0 ℳ⊕), partial shielding extends up to 200 GeV. Over the parameter range we studied, strong shielding does not occur for weakly magnetized planets. For a planet with a magnetic moment similar to that of Earth, particles with energies below 512 MeV are strongly shielded, and for strongly magnetized planets, this limit increases to 10 GeV. Conclusions: We find that magnetic shielding strongly controls the number of cosmic-ray particles reaching the planetary atmosphere. The implications of this increased particle flux are discussed in a companion article.

  17. Testing for uniformity of ultra-high energy cosmic ray arrival directions

    NASA Astrophysics Data System (ADS)

    Ivanov, A. A.

    2016-04-01

    Arrival directions of ultra-high energy cosmic rays (UHECRs) exhibit mainly an isotropic distribution with some small deviations in particular energy bins. In this paper, the Yakutsk array data are tested for circular uniformity of arrival directions in right ascension (RA) using two methods appropriate for the energy ranges below and above 1018 eV. No statistically significant deviation from uniformity is found in the arrival directions of cosmic rays (CRs) detected within the observation period 1974-2000.

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

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

    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.

  19. PREFACE: 24th European Cosmic Ray Symposium (ECRS)

    NASA Astrophysics Data System (ADS)

    2015-08-01

    The 24th European Cosmic Ray Symposium (ECRS) took place in Kiel, Germany, at the Christian-Albrechts-Universität zu Kiel from September 1 - 5, 2014, The first symposium was held in 1968 in Lodz, Poland (high energy, extensive air showers and astrophysical aspects) and in Bern (solar and heliospheric phenomena) and the two "strands" joined together in 1976 with the meeting in Leeds. The 24th ECRS covered a wide range of scientific issues divided into the following topics: HECR-I Primary cosmic rays I (experiments) HECR-II Primary cosmic rays II (theory) MN Cosmic ray muons and neutrinos GR GeV and TeV gamma astronomy SH Energetic particles in the heliosphere (solar and anomalous CRs and GCR modulation) GEO Cosmic rays and geophysics (energetic particles in the atmosphere and magnetosphere of the Earth) INS Future Instrumentation DM Dark Matter The organizers are very grateful to the Deutsche Forschungs Gemeinschaft for supporting the symposium.

  20. Transient cosmic ray increase associated with a geomagnetic storm

    NASA Technical Reports Server (NTRS)

    Kudo, S.; Wada, M.; Tanskanen, P.; Kodama, M.

    1985-01-01

    On the basis of worldwide network data of cosmic ray nucleonic components, the transient cosmic ray increase due to the depression of cosmic ray cutoff rigidity during a severe geomagnetic storm was investigated in terms of the longitudinal dependence. Multiple correlation analysis among isotropic and diurnal terms of cosmic ray intensity variations and Dst term of the geomagnetic field is applied to each of various station's data. It is shown that the amplitude of the transient cosmic ray increase associated with Dst depends on the local time of the station, and that its maximum phase is found in the evening sector. This fact is consistent with the theoretical estimation based on the azimuthally asymmetric ring current model for the magnetic DS field.

  1. Cosmic ray environment model for Earth orbit

    NASA Technical Reports Server (NTRS)

    Edmonds, L.

    1985-01-01

    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.

  2. Tevatron QCD for Cosmic-Rays

    SciTech Connect

    Sonnenschein, Lars; /RWTH Aachen U.

    2010-12-01

    The two multi-purpose experiments D0 and CDF are operated at the Tevatron collider, where proton anti-proton collisions take place at a centre of mass energy of 1.96 TeV in Run II. In the kinematic plane of Q{sup 2}-scale and (anti-)proton momentum fraction x, Tevatron jet measurements cover a wide range, with phase space regions in common and beyond the HERA ep-collider reach. The kinematic limit of the Auger experiment is given by a centre of mass energy of 100 TeV. Cosmic rays cover a large region of the kinematic phase space at low momenta x, corresponding to forward proton/diffractive physics and also at low scales, corresponding to the hadronization scale and the underlying event. Therefore of particular interest are exclusive and diffractive measurements as well as underlying event, double parton scattering and minimum bias measurements. The kinematic limit of the Tevatron corresponds to the PeV energy region below the knee of the differential cosmic particle flux energy distribution. The data discussed here are in general corrected for detector effects, such as efficiency and acceptance. Therefore they can be used directly for testing and improving existing event generators and any future calculations/models. Comparisons take place at the hadronic final state (particle level).

  3. Cosmic-ray physics with the milagro gamma-ray observatory

    SciTech Connect

    Sinnis, Gus

    2008-01-01

    The Milagro gamma-ray observatory is a water Cherenkov detector with an energy response between 100 GeV and 100 TeV. While the major scientific goals of Milagro were to detect and study cosmic sources of TeV gamma rays, Milagro has made measurements important to furthering our understanding of the cosmic radiation that pervades our Galaxy. Milagro has made the first measurement of the Galactic diffuse emission in the TeV energy band. In the Cygnus Region we measure a flux {approx}2.7 times that predicted by GALPROP. Milagro has also made measurements of the anisotropy of the arrival directions of the local cosmic radiation. On large scales the measurements made by Milagro agree with those previously reported by the Tibet AS{gamma} array. However, we have also discovered a time dependence to this anisotropy, perhaps due to solar modulation. On smaller scales, {approx}10 degrees, we have detected two regions of excess. These excesses have a spectrum that is inconsistent with the local cosmic-ray spectrum.

  4. Electron scattering effects in typical cosmic ray telescopes.

    NASA Technical Reports Server (NTRS)

    Lupton, J. E.; Stone, E. C.

    1972-01-01

    Laboratory measurements have been made of the response of two typical cosmic ray detector systems to electrons between 0.2 and 2.0 MeV. Working laboratory versions of each of these particle telescopes were exposed to the monoenergetic electron beam from a magnetic spectrometer. The results of pulse height and counting rate measurements indicate that electrons scattered from the anticoincidence cup comprise about 25% of the total number arriving at the top of the detector stack. In certain cases, the contribution of these scattered particles to the total number of electrons detected can reach 65%.

  5. PREFACE: 23rd European Cosmic Ray Symposium (and 32nd Russian Cosmic Ray Conference)

    NASA Astrophysics Data System (ADS)

    Erlykin, A. D.; Kokoulin, R. P.; Lidvansky, A. S.; Meroshnichenko, L. I.; Panasyuk, M. I.; Panov, A. D.; Wolfendale, A. W.

    2013-02-01

    The 23rd European Cosmic Ray Symposium (ECRS) took place in Moscow at the Lomonosov Moscow State University (3-7 July 2012), and was excellently organized by the Skobeltsyn Institute of Nuclear Physics of the Lomonosov Moscow State University, with the help of the Russian Academy of Sciences and the Council on the Complex Problem of Cosmic Rays of the Russian Academy of Sciences. The first symposia were held in 1968 in Lodz, Poland (high energy, extensive air showers and astrophysical aspects) and in Bern (solar and heliospheric phenomena) and the two 'strands' joined together in 1976 with the meeting in Leeds. Since then the symposia, which have been very successful, have covered all the major topics with some emphasis on European collaborations and on meeting the demands of young scientists. Initially, a driving force was the need to overcome the divisions caused by the 'Cold War' but the symposia continued even when that threat ceased and they have shown no sign of having outlived their usefulness. 2012 has been an important year in the history of cosmic ray studies, in that it marked the centenary of the discovery of enigmatic particles in the perilous balloon ascents of Victor Hess. A number of conferences have taken place in Western Europe during the year, but this one took place in Moscow as a tribute to the successful efforts of many former USSR and other Eastern European scientists in discovering the secrets of the subject, often under very difficult conditions. The symposium covers a wide range of scientific issues divided into the following topics: PCR-IPrimary cosmic rays I (E < 1015 eV) PCR-IIPrimary cosmic rays II (E > 1015 eV) MNCosmic ray muons and neutrinos GAGeV and TeV gamma astronomy SHEnergetic particles in the heliosphere (solar and anomalous CRs and GCR modulation) GEOCosmic rays and geophysics (energetic particles in the atmosphere and magnetosphere of the Earth) On a personal note, as I step down as co-founder and chairman of the International Advisory Committee, I should like to thank those very many colleagues and friends with whom I have had the pleasure of working over the past 45 years. These thanks are extended to the present organizers. The organizers are very grateful to the Russian Foundation of Basic Research and to the Dynasty non-profit foundation for financial support. Arnold Wolfendale

  6. Detection Prospects of the Cosmic Neutrino Background

    NASA Astrophysics Data System (ADS)

    Li, Yu-Feng

    The existence of the cosmic neutrino background (CνB) is a fundamental prediction of the standard Big Bang cosmology. Although current cosmological probes provide indirect observational evidence, the direct detection of the CνB in a laboratory experiment is a great challenge to the present experimental techniques. We discuss the future prospects for the direct detection of the CνB, with the emphasis on the method of captures on beta-decaying nuclei and the PTOLEMY project. Other possibilities using the electron-capture (EC) decaying nuclei, the annihilation of extremely high-energy cosmic neutrinos (EHECνs) at the Z-resonance, and the atomic de-excitation method are also discussed in this review.

  7. Detection prospects of the cosmic neutrino background

    NASA Astrophysics Data System (ADS)

    Li, Yu-Feng

    2015-04-01

    The existence of the cosmic neutrino background (CνB) is a fundamental prediction of the standard Big Bang cosmology. Although current cosmological probes provide indirect observational evidence, the direct detection of the CνB in a laboratory experiment is a great challenge to the present experimental techniques. We discuss the future prospects for the direct detection of the CνB, with the emphasis on the method of captures on beta-decaying nuclei and the PTOLEMY project. Other possibilities using the electron-capture (EC) decaying nuclei, the annihilation of extremely high-energy cosmic neutrinos (EHECνs) at the Z-resonance, and the atomic de-excitation method are also discussed in this review (talk given at the International Conference on Massive Neutrinos, Singapore, 9-13 February 2015).

  8. Directional clustering in highest energy cosmic rays

    SciTech Connect

    Goldberg, Haim; Weiler, Thomas J.

    2001-09-01

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

  9. Propagation and nucleosynthesis of ultraheavy cosmic rays

    NASA Technical Reports Server (NTRS)

    Giler, M.; Wibig, T.

    1985-01-01

    The observed fluxes of cosmic ray (C.R.) ultraheavy elements depend on their charge and mass spectrum at the sources and on the propagation effects, on the distribution of path lengths traversed by the particles on their way from the sources to the observation point. The effect of different path length distributions (p.l.d.) on the infered source abunances is analyzed. It seems that it is rather difficult to fit a reasonable p.l.d. so that the obtained source spectrum coincides with the Solar System (SS) abundances in more detail. It suggests that the nucleosynthesis conditions for c.r. nuclei may differ from that for SS matter. The nucleosynthesis of ultraheavy elements fitting its parameters to get the c.r. source abundances is calculated. It is shown that it is possible to get a very good agreement between the predicted and the observed source abundance.

  10. Cosmic-Ray Exposure Ages of Meteorites

    NASA Astrophysics Data System (ADS)

    Herzog, G. F.; Caffee, M. W.

    The concept 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. 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 their source region? How many distinct collisions on each parent body have created the known meteorites of each type? How often do parent bodies 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? This chapter touches on these questions as it examines the data. In recent years, CRE ages also have become important for interpreting small variations in the abundances of stable isotopes.

  11. TIROS-N Cosmic Ray study

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

    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.

  12. Galactic Cosmic Rays in the Outer Heliosphere

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

    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

  13. Cosmic Ray Variability and Galactic Dynamics

    NASA Astrophysics Data System (ADS)

    Medvedev, Mikhail

    2007-05-01

    The spectral analysis of fluctuations of biodiversity (Rohde & Muller, 2005) and the subsequent re-analysis of the diversity record, species origination and extinction rates, gene duplication, etc (Melott & Liebermann, 2007) indicate the presence of a 62$\\pm$3My cyclicity, for the last 500My. Medvedev & Melott (2006) proposed that the cyclicity may be related to the periodicity of the Solar motion with respect to the Galactic plane, which exhibits a 63My oscillation, and the inhomogeneous distribution of Cosmic Rays (CR) throughout the Milky Way, which may affect the biosphere by changing mutation rate, climate, food chain, etc. Here we present a model of CR propagation in the Galactic magnetic fields, in the presence of both the mean field gradient and the strong MHD turbulence in the interstellar medium. We explore the "magnetic shielding effect" as a function of CR energy and composition and estimate the resultant flux of mutagenic secondary muons at the Earth surface.

  14. Cosmic ray proton spectra at low rigidities

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

    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.

  15. Statistical reconstruction for cosmic ray muon tomography.

    PubMed

    Schultz, Larry J; Blanpied, Gary S; Borozdin, Konstantin N; Fraser, Andrew M; Hengartner, Nicolas W; Klimenko, Alexei V; Morris, Christopher L; Orum, Chris; Sossong, Michael J

    2007-08-01

    Highly penetrating cosmic ray muons constantly shower the earth at a rate of about 1 muon per cm2 per minute. We have developed a technique which exploits the multiple Coulomb scattering of these particles to perform nondestructive inspection without the use of artificial radiation. In prior work [1]-[3], we have described heuristic methods for processing muon data to create reconstructed images. In this paper, we present a maximum likelihood/expectation maximization tomographic reconstruction algorithm designed for the technique. This algorithm borrows much from techniques used in medical imaging, particularly emission tomography, but the statistics of muon scattering dictates differences. We describe the statistical model for multiple scattering, derive the reconstruction algorithm, and present simulated examples. We also propose methods to improve the robustness of the algorithm to experimental errors and events departing from the statistical model. PMID:17688203

  16. Cosmic ray decreases and magnetic clouds

    NASA Technical Reports Server (NTRS)

    Cane, H. V.

    1993-01-01

    A study has been made of energetic particle data, obtained from IMP 8, in conjunction with solar wind field and plasma data at the times of reported magnetic clouds. 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 postshock 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.

  17. Strong earthquakes, novae and cosmic ray environment

    NASA Technical Reports Server (NTRS)

    Yu, Z. D.

    1985-01-01

    Observations about the relationship between seismic activity and astronomical phenomena are discussed. First, after investigating the seismic data (magnitude 7.0 and over) with the method of superposed epochs it is found that world seismicity evidently increased after the occurring of novae with apparent magnitude brighter than 2.2. Second, a great many earthquakes of magnitude 7.0 and over occurred in the 13th month after two of the largest ground level solar cosmic ray events (GLEs). The causes of three high level phenomena of global seismic activity in 1918-1965 can be related to these, and it is suggested that according to the information of large GLE or bright nova predictions of the times of global intense seismic activity can be made.

  18. Estimates of cellular mutagenesis from cosmic rays

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Wilson, John W.

    1994-01-01

    A parametric track structure model is used to estimate the cross section as a function of particle velocity and charge for mutations at the hypoxanthine guanine phosphoribosyl transferase (HGPRT) locus in human fibroblast cell cultures. Experiments that report the fraction of mutations per surviving cell for human lung and skin fibroblast cells indicate small differences in the mutation cross section for these two cell lines when differences in inactivation rates between these cell lines are considered. Using models of cosmic ray transport, the mutation rate at the HGPRT locus is estimated for cell cultures in space flight and rates of about 2 to 10 x 10(exp -6) per year are found for typical spacecraft shielding. A discussion of how model assumptions may alter the predictions is also presented.

  19. Cosmic ray decreases and magnetic clouds

    SciTech Connect

    Cane, H.V. )

    1993-03-01

    A study has been made of energetic particle data, obtained from IMP 8, in conjunction with solar wind field and plasma data at the times of reported magnetic clouds. It is shown that magnetic clouds can cause a depression of the cosmic ray flux but high fields are required. A depression of 3% 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 postshock 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. 19 refs., 5 figs.

  20. Relativistic cosmic rays and corotating interaction regions

    SciTech Connect

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

    1981-09-01

    Analyses of relativistic galactic cosmic ray intensity variations have been conducted to determine the nature of the modulations that are related to the presence of corotating interaction regions (CIR) in interplanetary space. The corotating interaction regions have been identified from the plasma and field observations recorded by Pioneer 10 and 11 spacecrafts during the period 1972--1974. This investigation has established that the nucleonic intensity recorded at the polar stations Thule and McMurdo decreases as the streams associated with the CIR overtake the earth. However, this modulation occurs only for those CIR-associated streams in which a neutral sheet is imbedded. In contrast, geomagnetic storms are related to CIR streams with or without neutral sheets. Taken together, these results suggest that the ostensible effect of CIR'S on the intensity of high-energy particles is primarily a consequence of drifts related to neutral sheets, although diffusion effects cannot be ruled out at this stage.

  1. The anomalous component of cosmic rays

    NASA Technical Reports Server (NTRS)

    Jokipii, J. R.

    1990-01-01

    The paper discusses the nature of the anomalous component in the quiet-time cosmic-ray flux, which was observed first by Garcia-Munoz et al. (1973) and Hovestadt et al. (1973). Models of the anomalous component suggest that most of its observed properties, including the composition, time-dependence, energy spectrum, and spatial gradients, can be understood as a natural consequence of the acceleration of freshly-ionized interstellar neutral atoms at the termination shock of the solar wind. It is shown that the models reasonably agree with observations under the condition that the polar heliospheric magnetic field is modified to be larger and more transverse than its present models, as suggested by Jokipii and Kota (1989). The models suggest that the energy density of the anomalous component may modify the solar wind flow and shock if the shock is at a heliospheric distance which is significantly greater than 80-100 AU.

  2. The anomalous component of cosmic rays

    NASA Astrophysics Data System (ADS)

    Jokipii, J. R.

    The paper discusses the nature of the anomalous component in the quiet-time cosmic-ray flux, which was observed first by Garcia-Munoz et al. (1973) and Hovestadt et al. (1973). Models of the anomalous component suggest that most of its observed properties, including the composition, time-dependence, energy spectrum, and spatial gradients, can be understood as a natural consequence of the acceleration of freshly-ionized interstellar neutral atoms at the termination shock of the solar wind. It is shown that the models reasonably agree with observations under the condition that the polar heliospheric magnetic field is modified to be larger and more transverse than its present models, as suggested by Jokipii and Kota (1989). The models suggest that the energy density of the anomalous component may modify the solar wind flow and shock if the shock is at a heliospheric distance which is significantly greater than 80-100 AU.

  3. Fractality in high energy cosmic rays

    NASA Astrophysics Data System (ADS)

    Martinic, N. J.; Ticona, R.; Poma, I.; Osco, F.; Gutiérrez, R.

    2003-07-01

    Using EAS data from the EAS-EXC group (EAS plus hadronic calorimeter and nuclear emulsion-X chamber hybrid experiment) on Mount Chacaltaya during the 1990's the fractal properties of the energetic cosmic ray fluxes was investigated. A discrimination in the hadron content of the energetic primaries furnishes two different data samples, the total EAS fluxes and the hadron-less fluxes. The sidereal diurnal variation of the hadron-less EAS time variation shows values of 0.5% with a phase at about 2.29 hr sidereal time. With the help of the Crassberger Procaccia algorithm the fractal dimensions have been investigated of, on the one hand, the differences in arrival times of the hadron-less showers and on the other hand the EAS fluxes time series with an integration time of five min. The obtained fractal dimensions show inconclusive evidence of continuous chaotic component in the data samples investigated.

  4. Cosmic ray decreases and magnetic clouds

    NASA Technical Reports Server (NTRS)

    Cane, H. V.

    1992-01-01

    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.

  5. Cosmic ray propagation in galactic turbulence

    SciTech Connect

    Evoli, Carmelo; Yan, Huirong E-mail: hryan@pku.edu.cn

    2014-02-10

    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 and 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.

  6. ATIC Measurement of Cosmic Ray Heavy Ions

    NASA Astrophysics Data System (ADS)

    Guzik, T. G.; ATIC Collaboration

    2004-08-01

    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.

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

    NASA Technical Reports Server (NTRS)

    Wang, H. T.

    1973-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

    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.

  9. A new transition radiation detector for cosmic ray nuclei

    NASA Technical Reports Server (NTRS)

    Lheureux, J.; Meyer, P.; Muller, D.; Swordy, S.

    1981-01-01

    Test measurements on materials for transition radiation detectors at a low Lorentz factor are reported. The materials will be based on board Spacelab-2 for determining the composition and energy spectra of nuclear cosmic rays in the 1 TeV/nucleon range. The transition radiation detectors consist of a sandwich of radiator-photon detector combinations. The radiators emit X-rays and are composed of polyolefin fibers used with Xe filled multiwired proportional chamber (MWPC) detectors capable of detecting particle Lorentz factors of several hundred. The sizing of the detectors is outlined, noting the requirement of a thickness which provides a maximum ratio of transition radiation to total signal in the chambers. The fiber radiator-MWPC responses were tested at Fermilab and in an electron cyclotron. An increase in transition radiation detection was found as a square power law of Z, and the use of six radiator-MWPC on board the Spacelab-2 is outlined.

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

    NASA Astrophysics Data System (ADS)

    Mewaldt, Richard

    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.

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

    SciTech Connect

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

    2012-07-01

    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 μG. 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.

  12. The AGN Population and the Cosmic X-ray Background

    NASA Astrophysics Data System (ADS)

    Treister, Ezequiel; Urry, C. Meg; Schawinski, Kevin

    2015-08-01

    In order to fully understand galaxy formation we need to know when in the cosmic history are supermassive black holes (SMBHs) growing more intensively, in what type of galaxies this growth is happening and what fraction of these sources are invisible at most wavelengths due to obscuration. Active Galactic Nuclei (AGN) population synthesis models that can explain the spectral shape and intensity of the cosmic X-ray background (CXRB) indicate that most of the SMBH growth occurs in moderate-luminosity (Lx~1044 erg/s) sources (Seyfert-type AGN), at z~0.5-1 and in heavily obscured but Compton-thin, NH~1023 cm-2, systems.However, this is not the complete history, as a large fraction of black hole growth does not emit significantly in X-rays either due to obscuration, intrinsic low luminosities or large distances. Using a combination of X-ray stacking and multi wavelength selection techniques we constrain the amount of black hole accretion as a function of cosmic history, from z~0 to z~6. The integrated intensity at high energies indicates that a significant fraction of the total black hole growth, 22%, occurs in heavily-obscured systems that are not individually detected in even the deepest X-ray observations.We finally investigate the AGN triggering mechanism as a function of bolometric luminosity, finding evidence for a strong connection between significant black hole growth events and major galaxy mergers from z~0 to z~3, while less spectacular but longer accretion episodes are most likely due to other (stochastic) processes. AGN activity triggered by major galaxies is responsible for ~60% of the total black hole growth.

  13. Cosmic ray spectrum, composition, and anisotropy measured with IceCube

    NASA Astrophysics Data System (ADS)

    Tamburro, Alessio

    2014-04-01

    Analysis of cosmic ray surface data collected with the IceTop array of Cherenkov detectors at the South Pole provides an accurate measurement of the cosmic ray spectrum and its features in the "knee" region up to energies of about 1 EeV. IceTop is part of the IceCube Observatory that includes a deep-ice cubic kilometer detector that registers signals of penetrating muons and other particles. Surface and in-ice signals detected in coincidence provide clear insights into the nuclear composition of cosmic rays. IceCube already measured an increase of the average primary mass as a function of energy. We present preliminary results on both IceTop-only and coincident events analysis. Furthermore, we review the recent measurement of the cosmic ray anisotropy with IceCube.

  14. On the level of the cosmic ray sea flux

    SciTech Connect

    Casanova, S.; Aharonian, F. A.; Gabici, S.; Torii, K.; Fukui, Y.; Onishi, T.; Yamamoto, H.; Kawamura, A.

    2009-04-08

    The study of Galactic diffuse {gamma} radiation combined with the knowledge of the distribution of the molecular hydrogen in the Galaxy offers a unique tool to probe the cosmic ray flux in the Galaxy. A methodology to study the level of the cosmic ray 'sea' and to unveil target-accelerator systems in the Galaxy, which makes use of the data from the high resolution survey of the Galactic molecular clouds performed with the NANTEN telescope and of the data from {gamma}-ray instruments, has been developed. Some predictions concerning the level of the cosmic ray 'sea' and the {gamma}-ray emission close to cosmic ray sources for instruments such as Fermi and Cherenkov Telescope Array are presented.

  15. A search for microwave emission from cosmic ray air showers

    NASA Astrophysics Data System (ADS)

    Williams, Christopher Lee

    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.

  16. Plasma effects on extragalactic ultra-high-energy cosmic ray hadron beams in cosmic voids

    SciTech Connect

    Krakau, S.; Schlickeiser, R. E-mail: rsch@tp4.rub.de

    2014-07-01

    The linear instability of an ultrarelativistic hadron beam (Γ {sub b} ≈ 10{sup 6}) in the unmagnetized intergalactic medium (IGM) is investigated with respect to the excitation of collective electrostatic and aperiodic electromagnetic fluctuations. This analysis is important for the propagation of extragalactic ultrarelativistic cosmic rays (E > 10{sup 15} eV) from their distant sources to Earth. We calculate minimum instability growth times that are orders of magnitude shorter than the cosmic ray propagation time in the IGM. Due to nonlinear effects, especially the modulation instability, the cosmic ray beam stabilizes and can propagate with nearly no energy loss through the IGM.

  17. Gamma rays and the origin of Galactic Cosmic Rays

    NASA Astrophysics Data System (ADS)

    de Ona Wilhelmi, Emma

    2015-08-01

    Cosmic rays (CRs) are highly energetic nuclei (plus a small fraction of electrons) which fill the Galaxy and carry on average as much energy per unit volume as the energy density of starlight, the interstellar magnetic fields, or the kinetic energy density of interstellar gas. The CR spectrum extends as a featureless power-law up to ~2 PeV (the 'knee') and it is believed to be the result of acceleration of those CRs in Galactic Sources and later diffusion and convection in galactic magnetic fields. Those energetic CRs can interact with the surrounding medium via proton-proton collision resulting in secondary gamma-ray photons, observed from 100 MeV to a few tens of TeV. The results obtained by the current Cherenkov telescopes and gamma-ray satellites with the support of X-ray observations have discovered and identified more than 50 Galactic gamma-ray sources. Among them, the number of Supernova remnants (SNRs) and very-high-energy hard-spectrum sources (natural candidates to originate CRs) are steadily increasing. We expect to increase by a factor 10 at least this population of source with the future CTA experiment. I will review our current knowledge of Galactic gamma-ray sources and their connection with energetic CRs and the scientific prospects for CTA in this field. Those observations, together with a strong multi-wavelenght support from radio to hard X-rays, will finally allow us to establish the origin of the Galactic CRs.

  18. TeV Gamma Rays and Cosmic-Ray Acceleration in Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Buckley, James H.

    1998-04-01

    If supernova remnants (SNRs) are the site of cosmic-ray acceleration, the associated nuclear interactions should result in an observable flux of π^0-decay γ-rays for the nearest SNRs. Measurements of the TeV γ-ray flux from nearby, radio-bright SNRs have been made with the Whipple imaging air Cherenkov telescope but reveal no significant emission (Buckley et al. 1998). Three of these SNRs (IC443, γ-Cygni and W44) are spatially coincident with low-latitude unidentified sources detected with the Energetic Gamma-Ray Experiment Telescope (EGRET). If the EGRET γ-ray fluxes result from cosmic-ray interactions, then the EGRET and Whipple data are found to be collectively inconsistent with a cosmic-ray source spectrum flatter than ~ E-2.4. The Whipple upper limits for IC443 and γ-Cygni are also inconsistent with a priori predictions if these remnants are indeed expanding into regions where the average density of the interstellar medium is enhanced by the presence of molecular clouds. Recent observations of nonthermal X-rays in the limbs of a number of shell-type SNRs (including IC443, SN 1006 and Cassiopeia A) signify the presence of very high energy electrons (E>10 TeV) in the vicinity of SNR shells. More Recently, the CANGAROO atmospheric Cherenkov telescope has detected significant TeV emission from the remnant SN 1006 (Tanimori et al. 1998), but in this case the TeV emission most probably arises from inverse-Compton scattering by energetic electrons. Despite the growing body of evidence for shock acceleration of electrons in SNRs, there is still no direct evidence pointing to the source of cosmic ray nuclei and the data are beginning to require a modification of the simplest models of shock acceleration and energy dependent propagation of cosmic rays.

  19. Studies of the cosmic ray spectrum and large scale anisotropies with the KASCADE-Grande experiment

    NASA Astrophysics Data System (ADS)

    Chiavassa, A.; Apel, W. D.; Arteaga-Velázquez, J. C.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Cantoni, E.; Cossavella, F.; Curcio, C.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Fuchs, B.; Fuhrmann, D.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huber, D.; Huege, T.; Kampert, K.-H.; Kang, D.; Klages, H. O.; Link, K.; Łuczak, P.; Ludwig, M.; Mathes, H. J.; Mayer, H. J.; Melissas, M.; Milke, J.; Mitrica, B.; Morello, C.; Oehlschläger, J.; Ostapchenko, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schoo, S.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Zabierowski, J.

    2014-08-01

    KASCADE-Grande is an air shower observatory devoted to the detection of cosmic rays in the 1016 - 1018eV energy range. For each event the arrival direction, the total number of charged particles (Nch) and the total number of muons (Nμ), at detection level (i.e. 110 m a.s.l.), are measured. The detection of these observarbles, with high accuracy, allows the study of the primary spectrum, chemical composition and large scale anisotropies, that are the relevant informations to investigate the astrophysics of cosmic rays in this energy range. These studies are of main importance to deeply investigate the change of slope of the primary spectrum detected at ~ 4 × 1015 eV, also known as the knee, and to search for the transition from galactic to extra-galactic cosmic rays.

  20. Searching for New Physics with Ultrahigh Energy Cosmic Rays

    NASA Technical Reports Server (NTRS)

    Stecker, Floyd W.; Scully, Sean T.

    2009-01-01

    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.

  1. Searching for Cosmic Ray Radar Echos In TARA Data

    NASA Astrophysics Data System (ADS)

    Myers, Isaac

    2013-04-01

    The TARA (Telescope Array Radar) cosmic ray detector has been in operation for about a year and half. This bi-static CW radar detector was designed with the goal of detecting cosmic rays in coincidence with Telescope Array (TA). For the majority of its operation it has been in the TARA1.5 phase in which a 1.5 kW transmitter broadcasts from a single Yagi antenna across the TA surface detector array to our receiver station 50 km away. Our initial DAQ system has obtained millions of triggers utilizing a USRP2 PC controlled radio. During recent months, we have commissioned a 250 MHz sample rate detector with an intelligent self-triggering algorithm that can detect radar echo chirp signals below the noise. I will describe the stages of analysis used for comparing TARA radar triggers with TA data and present a synopsis of the analysis of the USRP2 data and preliminary results from the more advanced DAQ system.

  2. Cosmic-ray antimatter - A primary origin hypothesis

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

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

  3. Predicting the Cosmic-Ray Environment Near Earth

    NASA Technical Reports Server (NTRS)

    Edmonds, L.

    1986-01-01

    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.

  4. Cosmic Ray Anisotropy Near a CME-Driven Shock

    NASA Astrophysics Data System (ADS)

    Leerungnavarat, K.; Ruffolo, D.; Bieber, J. W.

    2002-05-01

    As a CME-driven shock approaches and passes earth, neutron monitors and muon detectors observe enhancements of the cosmic ray anisotropy. Precursor anisotropies are caused by the interaction of the cosmic rays with the shock and provide useful information for space weather forecasting with a lead time of several hours. We numerically simulate the distribution of particles in position and pitch angle, and predict how the cosmic ray pitch angle distribution near the shock depends on particle energy and shock geometry. This work was supported by NSF grant ATM-0000315 and the Thailand Research Fund.

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

    NASA Technical Reports Server (NTRS)

    Webb, G. M.

    1985-01-01

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

  6. Satellite measurements of the isotopic composition of galactic cosmic rays

    NASA Technical Reports Server (NTRS)

    Mewaldt, R. A.; Spalding, J. D.; Stone, E. C.; Vogt, R. E.

    1979-01-01

    The individual isotopes of galactic cosmic ray Ne, Mg, and Si at 100 MeV/nucleon were clearly resolved with an rms mass resolution of 0.20 amu. The results suggest the cosmic ray source is enriched in Ne-22, Mg-25, and Mg-26 when compared to the solar system. The ratio of (Mg-25)+(Mg-26) to Mg-24, which is approximately 0.49 compared to the solar system value of 0.27, suggest that the cosmic ray source and solar system material were synthesized under different conditions.

  7. Galactic Propagation of Cosmic Rays from Individual Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Nierstenhöfer, Nils; Graeser, Philipp; Schuppan, Florian; Tjus, Julia

    2015-08-01

    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.

  8. Exploring Cosmic X-ray Source Polarization

    NASA Technical Reports Server (NTRS)

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

    2008-01-01

    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.

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

    SciTech Connect

    Fornengo, N.; Vittino, A.; Maccione, L. E-mail: luca.maccione@lmu.de

    2014-04-01

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

  10. Cosmic ray decreases and shock structure: A multispacecraft study

    NASA Technical Reports Server (NTRS)

    Cane, H. V.; Richardson, I. G.; Von Rosenvinge, T. T.; Wibberenz, G.

    1994-01-01

    We examine greater than 60-MeV/amu ion data from three spacecraft (IMP 8 and Helios 1 and 2) at the time of a number of short term (less than 20-day duration) cosmic ray decreases (greater than 1 GeV) detected by ground-based neutron monitors in the years 1976 to 1979. The multispacecraft data allow us to investigate the structure of the modulation region and in particular the relative importance, as a function of location, of the shock and shock driver (ejecta) in causing the reduction in particle densities. Although the shocks contributing to cosmic ray decrease often have particle enhancements associated with them in the greater than 60-meV/amu data, this is not the case for three of the events discussed in this paper where a shock-associated decrease is also evident. Whereas the shock can cause an increase or decrease at low (i.e., less than neutron monitor) energies, the reduction of particle densities in the driver, if it is intercepted, is usually evident at all energies. Thus the overall shape of a decrease at greater than 60 MeV/amu depends primarily on whether the ejecta is intercepted. We find that the particle density inside ejecta increases with increasing radical distance from the Sun. In many of the events in this study, entry and exit of ejecta are accompanied by abrupt changes in the decrease and recovery rates which indicate that the effect of the ejecta is local. In contrast, the effect of the shock lasts many days after the shock has passed by and is evident at large angular distances from the longitude of the solar source, i.e., the effect of the shock is nonlocal. Within 1 AU there seems to be no radial dependence of the shock effect. One cosmic ray decrease seen at Earth, which had an unusual profile, can be understood if the median plane of the ejecta was inclined to the ecliptic.

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

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

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

  12. Galactic cosmic ray variations at the moon

    NASA Astrophysics Data System (ADS)

    Case, Anthony W.

    2011-05-01

    Galactic Cosmic Rays (GCR) are the predominant source of highly energetic particles in the inner heliosphere during solar quiet times. These particles are fully ionized atoms that are accelerated to near-relativistic speeds during events of extreme energy release throughout the Milky Way Galaxy and beyond. Some GCR particles eventually find their way to the outer edges of the heliosphere and a portion of those are able to propagate to 1 AU. GCR have sufficient energy to ionize atoms and molecules in the matter that they impact, causing radiation damage to both robotic and biologic materials. Understanding the flux and spectrum of GCR is of great importance to future robotic and human explorers venturing beyond low-Earth orbit. In this dissertation, we use the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) instrument along with modeling efforts to study a variety of phenomena that can influence the energetic particle flux in the near-Moon environment, including Interplanetary Coronal Mass Ejections (ICMEs), Corotating Interaction Regions (CIRs) and the Earth's magnetotail. As part of this study, the CRaTER instrument and its calibration are discussed in detail. A new model is developed to better predict the transit times of Interplanetary Coronal Mass Ejections and the associated drops in GCR flux called Forbush decreases. This model could provide a more accurate estimate of an ICME's arrival time within hours of ejection from the Sun. An important model discrepancy is resolved by using the CRaTER instrument to measure GCR while the Moon is in the Earth's magnetotail. Previous studies that predicted shielding of GCR by the magnetotail are disproven; we find no evidence for a drop in GCR, intensity as a result of passage through the magnetotail. We use the CRaTER instrument to investigate step-like durable decreases in GCR flux with time. We find that these decreases occurred when CIRs convected past the observing spacecraft shortly after solar minimum, presumably caused by the more effective shielding provided by the outward propagating magnetic structures. A change in the proton linear energy transfer spectrum is observed in conjunction with the GCR flux decrease.

  13. The ?-ray and neutrino background and cosmic chemical evolution

    NASA Astrophysics Data System (ADS)

    Hartmann, D. H.; Watanabe, K.; Leising, M. D.; The, L.-S.; Woosley, S. E.

    1997-05-01

    The global star formation history of the universe and the associated supernova rate are now reasonably well known. Core collapse supernovae are copious sources of neutrinos, and produce an integrated neutrino flux at Earth of ~10 neutrinos/cm2 s for each flavor. While terrestrial and extraterrestrial neutrino backgrounds exceed the supernova flux below ~15 MeV and above ~40 MeV, in the intermediate band the neutrino background from Type II/Ib supernovae may be detectable. Similarly, Type Ia supernovae produce the bulk of the extragalactic ?-ray background in the MeV range, while blazars dominate at higher energies and Seyfert galaxies at lower energies. The ?-ray and neutrino background probe cosmic chemical evolution.

  14. Neutrino flavor ratios modified by cosmic-ray secondary acceleration

    NASA Astrophysics Data System (ADS)

    Kawanaka, Norita; Ioka, Kunihito

    2015-10-01

    Acceleration of π 's and μ 's modifies the flavor ratio at Earth (at astrophysical sources) of neutrinos produced by π decay, νe∶νμ∶ντ , from 1 ∶1 ∶1 (1 ∶2 ∶0 ) to 1 ∶1.8 ∶1.8 (0 ∶1 ∶0 ) at high energy, because π 's decay more than μ 's during secondary acceleration. The neutrino spectrum accompanies a flat excess, differently from the case of energy losses. With the flavor spectra, we can probe time scales of cosmic-ray acceleration and shock dynamics. We obtain general solutions of convection-diffusion equations and apply them to gamma-ray bursts, which may have the flavor modification at around PeV-EeV detectable by IceCube and next-generation experiments.

  15. Peculiar high energy cosmic ray stratospheric event reveals a heavy primary origin particle above the knee region of the cosmic ray spectrum

    SciTech Connect

    Kopenkin, V.; Fujimoto, Y.

    2005-01-15

    We wish to put forward an explanation for a peculiar cosmic ray event with energy {sigma}E{sub {gamma}}{>=}2x10{sup 15} eV detected in 1975 by the balloon borne emulsion chamber experiment performed in the stratosphere, at the altitude {>=}30 km above sea level. For almost 30 years the event has been described as unusual, invoking new exotic mechanisms or models. In our opinion there is no need for an extraordinary explanation. Contrary to the widespread belief, the event gives us an example of 'unrecognized standard physics'. At the same time this event revealed a variety of features which are of considerable interest for cosmic rays, nuclear physics, and astrophysics. Here we show that the observed family is most likely to be a result of a heavy nucleus interaction with an air nucleus. In this case a primary particle would originally have been in the energy region above 'the knee' of the cosmic ray spectrum.

  16. Development of High Resolution Solid-State Track Detector for Ultra Heavy Cosmic Ray Observation

    NASA Astrophysics Data System (ADS)

    Kodaira, S.; Doke, T.; Hareyama, M.; Hasebe, N.; Ota, S.; Sakurai, K.; Sato, M.; Yasuda, N.; Nakamura, S.; Kamei, T.; Tawara, H.; Ogura, K.

    The observation of trans-iron nuclei in galactic cosmic rays (Z?30) requires a high performance cosmic ray detector telescope with a very large exposure area because of their extremely low fluxes. It is realized by the use of solid-state track detector of CR-39, which has an advantage of easy extension of exposure area. The verification of mass and nuclear charge identifications with CR-39 solid-state track detector newly developed for the observation of heavy cosmic ray particles has been made using Fe ions from NIRS-HIMAC. Mass and charge resolutions for Fe nuclei are found to be ~0.22 amu and 0.22 cu in rms, respectively. Moreover, it is necessary to raise the Z/??detection threshold in order to suppress background tracks produced by galactic cosmic rays with Z/?<30. The new track detectors of copolymers of CR-39 and DAP (diallyl phthalate) have been developed and verified their performances. From the point of view of stability for the cosmic ray exposure environment such as temperature and vacuum in space, newly BP-1 glass detector with high sensitivity is also currently under development. The combination of such solid-state track detector with the high speed scanning system enables us to realize a large-scaled observation for trans-iron galactic cosmic rays.

  17. The Origin of Cosmic Rays: What can GLAST Say?

    NASA Technical Reports Server (NTRS)

    Ormes, Jonathan F.; Digel, Seith; Moskalenko, Igor V.; Moiseev, Alexander; Williamson, Roger

    2000-01-01

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

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

    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...

  19. The Determination of the Muon Magnetic Moment from Cosmic Rays

    ERIC Educational Resources Information Center

    Amsler, C.

    1974-01-01

    Describes an experiment suited for use in an advanced laboratory course in particle physics. The magnetic moment of cosmic ray muons which have some polarization is determined with an error of about five percent. (Author/GS)

  20. An Empirical Model for Determination of the Cosmic Ray Spectra

    NASA Astrophysics Data System (ADS)

    Buchvarova, M.; Velinov, P.

    2006-12-01

    The high-energy charged particles entering the Earth's environment from interplanetary space have the significant effect on the space weather. We propose an improved model, which generalizes the differential D(E) and integral D(>E) spectra of galactic (GCR) and anomalous cosmic ray (ACR) protons and heavier elements during the 11-year solar cycle. The model takes into account the cosmic ray (CR) modulation by the solar wind and numerous solar and heliospheric events during different levels of solar activity. Modulated energy spectrum of galactic cosmic rays is compared with force field approximation. The difference is in the order of 1.5 %. The model solutions are compared with IMAX-92, CAPRICE-94 and AMS-98 measurements. This computed analytical model gives practical possibility for investigation of experimental data from measurements of galactic cosmic rays and their anomalous component. The obtained parameters are used for determination the profiles of the ionization in the ionosphere and middle atmosphere.

  1. Nonlinear Transport of Cosmic Rays in Turbulent Magnetic Field

    NASA Astrophysics Data System (ADS)

    Yan, H.; Xu, S.

    2014-09-01

    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.

  2. Galactic cosmic rays and N2 dissociation on Titan

    NASA Astrophysics Data System (ADS)

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

    1983-07-01

    The electromagnetic and particle cascade resulting from the absorption of galactic cosmic rays in the atmosphere of Titan is shown to be an important mechanism for driving the photochemistry at pressures of 1 to 50 mbar in the atmosphere. In particular, the cosmic ray cascade dissociates N2, a process necessary for the synthesis of nitrogen organics such as HCN. The important interactions of the cosmic ray cascade with the atmosphere are discussed. The N2 excitation and dissociation rates and the ionization rates of the principal atmospheric consituents are computed for a Titan model atmosphere that is consistent with Voyager 1 observations. It is suggested that HCN may be formed efficiently in the lower atmosphere through the photodissociation of methylamine. It is also argued that models of nitrogen and hydrocarbon photochemistry in the lower atmosphere of Titan should include the absorption of galactic cosmic rays as an important energy source.

  3. Cosmic-Ray Effects of Propagating Shocks Including the Heliosheath

    NASA Astrophysics Data System (ADS)

    Jokipii, J. R.; Kota, J.

    2001-08-01

    It has been known for a long time (Jokipii, et al, 1993) that the e~@ects of tt he heliosphere on cosmic rays extends beyond the termination shock and into the heliosheath. The inclusion of the region beyond the termination shock into models of modulation is still relatively recent. The previously-published model resultshave all been for a stationary system. We have modi~Aed our two-dimensional heliosperic cosmic-ray simulation code to be time dependent and to include a propagating shock wave which propagates out from the Sun and into the Heliosheath. The code follows the time variation of the intensity of both galacticand anomalous cosmic rays as the shock propagates past the point of observation and beyond. The results from the model simulations will be compared with recent observational results suggesting e~@ects of the heliosheath on galacticc and anomalous cosmic rays.

  4. A Search for Antimatter in the Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Greene, Nathaniel R.

    1997-01-01

    This work concerns the study of the composition of cosmic rays with two balloon-borne instruments, SMILI (Superconducting Magnetic Instrument for Light Isotopes), and MAGPIE (MAGnetic Passive Isotope Experiment). The principal result of this thesis is a new upper limit on the fraction of antihelium in the cosmic rays. This result, based on a sample of 16,000 helium events, limits the amount of antimatter that can be present in our Galaxy. Also presented are new data analysis techniques that have been developed to determine the masses of the light cosmic ray nuclei (lithium, beryllium, and boron) with unprecedented precision. In addition, this thesis contains a description of the analysis of nuclear tracks in the detectors of MAGPIE, a prototype apparatus flown from Antarctica to explore novel techniques for improved measurements of cosmic ray composition.

  5. Refractory nuclides in the cosmic-ray source

    NASA Technical Reports Server (NTRS)

    Wiedenbeck, M. E.; Binns, W. R.; Cummings, A. C.; Davis, A. J.; Nolfo, G. de; George, J. S.; Israel, M. H.; Labrador, A. W.; Leske, R. A.; Mewaldt, R. A.; Stone, E. C.; Rosenvinge, T. T. von

    2003-01-01

    New observations of the abundances and energy spectra of the isotopes of Mg, Al, and Si from ACE/CRIS are used to extend our previous results on the composition of refractory nuclides in cosmic-ray source material.

  6. Cosmic rays and the birth of particle physics

    NASA Astrophysics Data System (ADS)

    Friedlander, Michael

    2013-02-01

    Twenty years after the discovery of cosmic rays, the methods of research and resulting discoveries were dramatically changed by the introduction of experimental methods that made visible the passage of individual particles. Between 1932 and 1955, tracks of cosmic rays were found in cloud chambers and special photographic emulsions. From measurements of the ionization produced along these tracks, the mass, charge and energy of a single relativistic particle could be determined. The dynamics of decays and collisions could be analyzed. Positrons and then electron-positron pairs were discovered, followed by muons and pions and then the inhabitants of the 'particle zoo'. Fundamental concepts were challenged. From the mid- 1950s, larger accelerators began to produce many of the 'new' particles, displacing cosmic rays from their prime role in particle studies. But without the initial discoveries in cosmic rays, there might well not be the modern industrial-scale particle physics research.

  7. Cosmic-ray exposure records and origins of meteorites

    NASA Technical Reports Server (NTRS)

    Reedy, R. C.

    1985-01-01

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

  8. Thunderstorms, cosmic rays, and solar-lunar influences

    SciTech Connect

    Lethbridge, M.D.

    1990-08-20

    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.

  9. MDAC solar cosmic ray experiment on OGO-6

    NASA Technical Reports Server (NTRS)

    Masley, A. J.

    1973-01-01

    The instrumentation of the OGO-F solar cosmic ray experiment is described and results of data obtained during the satellite lifetime from launch on June 5, 1969, through September, 1970, and discussed.

  10. Explosions of massive stars with magnetic winds: cosmic ray acceleration

    NASA Astrophysics Data System (ADS)

    Stanev, T.

    We follow the consequences of cosmic ray acceleration in supernova remnants from the explosions of massive stars in the pre-supernova stellar winds. The theory for such acceleration predicts that in small fraction of the remnants - its polar caps - cosmic rays will be accelerated on a flat spectrum and will dominate the highest energies. This has been observed in the spectra of different cosmic ray nuclei. The same theory predicts cosmic ray electron spectra having E-3 slope up to 1,000 GeV and higher positron to electron ratio above 10 GeV. These relatively flat electron spectra may explain the WMAP haze in the vicinity of the galactic center.

  11. Cosmic Rays and Their Radiative Processes in Numerical Cosmology

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

    A cosmological hydrodynamic code is described, which includes a routine to compute cosmic ray acceleration and transport in a simplified way. The routine was designed to follow explicitly diffusive, acceleration at shocks, and second-order Fermi acceleration and adiabatic loss in smooth flows. Synchrotron cooling of the electron population can also be followed. The updated code is intended to be used to study the properties of nonthermal synchrotron emission and inverse Compton scattering from electron cosmic rays in clusters of galaxies, in addition to the properties of thermal bremsstrahlung emission from hot gas. The results of a test simulation using a grid of 128 (exp 3) cells are presented, where cosmic rays and magnetic field have been treated passively and synchrotron cooling of cosmic ray electrons has not been included.

  12. Influence of magnetic clouds on cosmic ray intensity variations

    NASA Technical Reports Server (NTRS)

    BADRUDDIN; Yadav, R. S.; Yadav, N. R.; Agrawal, S. P.

    1985-01-01

    Neutron monitor data has been analyzed to study the nature of galactic cosmic ray transient modulation associated with three types of interplanetary magnetic clouds - clouds associated with shocks, stream interfaces and cold magnetic enhancements.

  13. UNDERSTANDING TeV-BAND COSMIC-RAY ANISOTROPY

    SciTech Connect

    Pohl, Martin; Eichler, David E-mail: eichler@bgu.ac.il

    2013-03-20

    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.

  14. Cosmic Rays Variation Before Changes in Sun-Earth Environment

    NASA Astrophysics Data System (ADS)

    Mukherjee, S.

    2011-12-01

    Influence of cosmic rays variations on the Sun-Earth Environment has been observed before the changes in the atmospheric temperature, outbreak of influenza, cyclone, earthquake and tsunami. It has been recorded by Sun Observatory Heleospheric Observatory (SOHO) satellite data. Before the earthquake and tsunami the planetary indices (Kp) and Electron flux (E-flux) shows sudden changes followed by the atmospheric perturbations including very high temperature rise to sudden fall resulting snowfall in high altitude and rainfall in tropical areas. The active fault zones shows sudden faulting after the sudden drop in cosmic ray intensity and rise in Kp and E-flux. Besides the geo-environment the extraterrestrial influence on outbreak of H1N1 influenza has also been recorded based on the Mexico Cosmic ray data and its correlation with SOHO records. Distant stars have the potential to influence the heliophysical parameters by showering cosmic rays.

  15. Cosmic ray scattering in compressible turbulence

    NASA Astrophysics Data System (ADS)

    Lazarian, A.; Beresnyak, A.

    2006-12-01

    We study the scattering of low-energy cosmic rays (CRs) in a turbulent, compressive magnetohydrodynamic (MHD) fluid. We show that compressible MHD modes - fast or slow waves with wavelengths smaller than CR mean free paths induce cyclotron instability in CRs. The instability feeds the new small-scale Alfvénic wave component with wavevectors mostly along magnetic field, which is not a part of the MHD turbulence cascade. This new component gives feedback on the instability through decreasing the CR mean free path. We show that the ambient turbulence fully suppresses the instability at large scales, while wave steepening constrains the amplitude of the waves at small scales. We provide the energy spectrum of the plane-parallel Alfvénic component and calculate mean free paths of CRs as a function of their energy. We find that for the typical parameters of turbulence in the interstellar medium and in the intercluster medium the new Alfvénic component provides the scattering of the low-energy CRs that exceeds the direct resonance scattering by MHD modes. This solves the problem of insufficient scattering of low-energy CRs in the turbulent interstellar or intracluster medium that was reported in the literature.

  16. Drift Kinetic Theory and Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Webb, G. M.; Le Roux, J. A.; Zank, G. P.

    2009-11-01

    Starting from the Vlasov or Boltzmann equation for cosmic rays in a random and regular magnetic field, we introduce guiding center coordinates and transform the velocity to a frame moving at the electric field drift velocity. The resultant equation is written in terms of the parallel and perpendicular momentum and gyro-phase of the particle, and describes spatial particle transport in guiding center coordinates. Using the drift ordering in which the gyro-scale and gyro-period are assumed short compared to the background flow length and time scales, and averaging over the gyro-phase gives the drift kinetic equation in which the adiabatic moment and total particle energy in the inertial frame are used to describe the momentum and energy of the particle. If the parallel electric field is small, the adiabatic moment of the particles is conserved to lowest order in the drift ordering. The resultant drift kinetic equation properly takes into account the energy changes of the particles due to drifts along the electric field, and betatron acceleration, but contains only the lowest order approximation for the guiding center drift velocity to describe the spatial advection of the particles. A further transformation of variables, in which the particle momentum and pitch angle are specified in the local fluid frame, gives the focussed transport equation derived by Skilling [1] to describe particle transport in a moving plasma medium, such as the solar wind. The connections to previous derivations of the Skilling's pitch angle focussed transport equation are discussed.

  17. A Cosmic Ray Telescope For Educational Purposes

    SciTech Connect

    Voulgaris, G.; Kazanas, S.; Chamilothoris, I.

    2010-01-21

    Cosmic ray detectors are widely used, for educational purposes, in order to motivate students to the physics of elementary particles and astrophysics. Using a 'telescope' of scintillation counters, the directional characteristics, diurnal variation, correlation with solar activity, can be determined, and conclusions about the composition, origin and interaction of elementary particles with the magnetic field of earth can be inferred. A telescope was built from two rectangular scintillator panels with dimensions: 91.6x1.9x3.7 cm{sup 3}. The scintillators are placed on top of each other, separated by a fixed distance of 34.6 cm. They are supported by a wooden frame which can be rotated around a horizontal axis. Direction is determined by the coincidence of the signals of the two PMTs. Standard NIM modules are used for readout. This device is to be used in the undergraduate nuclear and particle physics laboratory. The design and construction of the telescope as well as some preliminary results are presented.

  18. Calibration of the Galactic Cosmic Ray Flux

    NASA Technical Reports Server (NTRS)

    Mathew, K. J.; Marti, K.

    2004-01-01

    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.

  19. Altitude variation of cosmic-ray neutrons.

    PubMed

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

    1987-11-01

    The altitude variation of the cosmic-ray neutron energy spectrum and the dose equivalent rate was measured at an average geomagnetic latitude of 24 degrees N by using the high-efficiency multi-sphere neutron spectrometer and neutron dose-equivalent counter developed by the authors. The data were obtained from a 2-h flight over Japan on 27 February 1985. The neutron energy spectra measured at sea level and at altitudes of 4,880 m and at 11,280 m were compared with the calculated spectra of O'Brien and with other experimental spectra, and they are in moderately good agreement with them. The dose equivalent rate increases according to a quadratic curve up to about 6,000 m and then increases linearly between 6,000 m and 11,280 m. The dependence of dose equivalent rates at sea level and at an altitude of 12,500 m on geomagnetic latitude also is given by referring to other experimental results. PMID:3667276

  20. Relativistic cosmic rays and corotating interaction regions

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

    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.

  1. The origin of galactic cosmic rays

    NASA Astrophysics Data System (ADS)

    Amato, Elena

    2014-05-01

    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.

  2. Solution to the cosmic ray anisotropy problem.

    PubMed

    Mertsch, Philipp; Funk, Stefan

    2015-01-16

    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

  3. Solution to the Cosmic Ray Anisotropy Problem

    NASA Astrophysics Data System (ADS)

    Mertsch, Philipp; Funk, Stefan

    2015-01-01

    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.

  4. Maximum entropy analysis of cosmic ray composition

    NASA Astrophysics Data System (ADS)

    Nosek, Dalibor; Ebr, Jan; Vícha, Jakub; Trávníček, Petr; Nosková, Jana

    2016-03-01

    We focus on the primary composition of cosmic rays with the highest energies that cause extensive air showers in the Earth's atmosphere. A way of examining the two lowest order moments of the sample distribution of the depth of shower maximum is presented. The aim is to show that useful information about the composition of the primary beam can be inferred with limited knowledge we have about processes underlying these observations. In order to describe how the moments of the depth of shower maximum depend on the type of primary particles and their energies, we utilize a superposition model. Using the principle of maximum entropy, we are able to determine what trends in the primary composition are consistent with the input data, while relying on a limited amount of information from shower physics. Some capabilities and limitations of the proposed method are discussed. In order to achieve a realistic description of the primary mass composition, we pay special attention to the choice of the parameters of the superposition model. We present two examples that demonstrate what consequences can be drawn for energy dependent changes in the primary composition.

  5. Cosmic Rays propagation in the Heliosphere

    NASA Astrophysics Data System (ADS)

    Bobik, P.; Boschini, M. J.; Consolandi, C.; Della Torre, S.; Gervasi, M.; Grandi, D.; Kudela, K.; Noventa, F.; Pensotti, S.; Rancoita, P. G.

    2012-08-01

    The cosmic rays modulation inside the heliosphere is well described by a transport equation introduced by Parker in 1958. We used the HelMed Monte Carlo code to reproduce the modulation effect in the inner heliosphere depending from solar activity and solar polarity. In this 2-D MonteCarlo approach we include a general treatment of the diffusion tensor that compound an enhancement of perpendicular diffusion coefficient at high solar latitude and a polar increased magnetic field. In our simulation we considered a heliosphere that changes the modulation parameter with the distance from the Earth, including periods prior to the one we intend to simulate. In this work we furthermore exploited the energy distribution of injected particles to the observed flux. We compared HelMed results with data of BESS-97, AMS-98, BESS-98, BESS-99, BESS-2000, BESS-2002 and PAMELA; this covering a period of 11 years and two solar polarity, these simulations are well in agreement with experimental data.

  6. Space Weather, Cosmic Rays, and Satellite Anomalies

    NASA Astrophysics Data System (ADS)

    Lev, Dorman

    Results are presented of the Satellite Anomaly Project, which aims to improve the methods of safeguarding satellites in the Earth’s 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 to be different for various orbits, and this should be taken into account when developing anomaly frequency models. The preliminary anomaly frequency models are presented.

  7. The escape model for Galactic cosmic rays

    NASA Astrophysics Data System (ADS)

    Giacinti, G.; Kachelrieß, M.; Semikoz, D. V.

    2015-08-01

    The escape model explains the cosmic ray (CR) knee by energy-dependent CR leakage from the Milky Way, with an excellent fit to all existing data. We test this model calculating the trajectories of individual CRs in the Galactic magnetic field. We find that the CR escape time τesc(E) exhibits a knee-like structure around E/Z = few × 1015 eV for small coherence lengths and strengths of the turbulent magnetic field. The resulting intensities for different groups of nuclei are consistent with the ones determined by KASCADE and KASCADE-Grande, using simple power-laws as injection spectra. The transition from Galactic to extragalactic CRs happens in this model at low energies and is terminated below ≈ 3 × 1018 eV. The intermediate energy region up to the ankle is populated by CRs accelerated in starburst galaxies. This model provides a good fit to ln(A) data, while the estimated CR dipole anisotropy is close to, or below, upper limits in the energy range 1017 - 1018 eV. The phase of the dipole is expected to change between 1 × 1017 and 3 × 1018 eV.

  8. Progress towards a measurement of the UHE cosmic ray electron flux using the CREST Instrument

    NASA Astrophysics Data System (ADS)

    Musser, Jim; Wakely, Scott; Coutu, Stephane; Geske, Matthew; Nutter, Scott; Tarle, Gregory; Park, Nahee; Schubnell, Michael; Gennaro, Joseph; Muller, Dietrich

    2012-07-01

    Electrons of energy beyond about 3 TeV have never been detected in the flux of cosmic rays at Earth despite strong evidence of their presence in a number of supernova remnants (e.g., SN 1006). The detection of high energy electrons at Earth would be extremely significant, yielding information about the spatial distribution of nearby cosmic ray sources. With the Cosmic Ray Electron Synchrotron Telescope (CREST), our collaboration has adopted a novel approach to the detection of electrons of energies between 2 and 50 TeV which results in a substantial increase in the acceptance and sensitivity of the apparatus relative to its physics size. The first LDB flight of the CREST detector took place in January 2012, with a float duration of approximately 10 days. In this paper we describe the flight performance of the instrument, and progress in the analysis of the data obtained in this flight.

  9. Ultra-High Energy Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Colon, Rafael Antonio; Moncada, Roberto; Guerra, Juan; Anchordoqui, Luis

    2016-01-01

    The search for the origin(s) of ultra-high energy (UHE) cosmic rays (CR) remains one of the cornerstones of high energy astrophysics. The previously proposed sources of acceleration for these UHECRs were gamma-ray bursts (GRB) and active galactic nuclei (AGN) due to their energetic activity and powerful jets. However, a problem arises between the acceleration method and the observed CR spectrum. The CRs from GRBs or AGN jets are assumed to undergo Fermi acceleration and a source injection spectrum proportional to E^-2 is expected. However, the most recent fits to the spectrum and nuclear composition suggest an injection spectrum proportional to E^-1. It is well known that such a hard spectrum is characteristic of unipolar induction of rotating compact objects. When this method is applied to the AGN cores, they prove to be much too luminous to accelerate CR nuclei without photodisintegrating, thus creating significant energy losses. Instead, here we re-examine the possibility of these particles being accelerated around the much less luminous quasar remnants, or dead quasars. We compare the interaction times of curvature radiation and photodisintegration, the two primary energy loss considerations with the acceleration time scale. We show that the energy losses at the source are not significant enough as to prevent these CRs from reaching the maximum observed energies. Using data from observatories in the northern and southern sky, the Telescope Array and the Pierre Auger Observatory respectively, two hotspots have been discerned which have some associated quasar remnants that help to motivate our study.

  10. Cosmic-ray Positrons from Millisecond Pulsars

    NASA Astrophysics Data System (ADS)

    Venter, C.; Kopp, A.; Harding, A. K.; Gonthier, P. L.; Büsching, I.

    2015-07-01

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

  11. Cosmic Ray Anomalies from the MSSM?

    SciTech Connect

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

    2011-08-11

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

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

    NASA Astrophysics Data System (ADS)

    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

    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 γ-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 γ-ray emission. Here we report the detection of >700-GeV γ-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.

  13. Cosmic Ray Ruggedness of Power Semiconductor Devices for Hybrid Vehicles

    NASA Astrophysics Data System (ADS)

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

    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.

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

    NASA Technical Reports Server (NTRS)

    Jokipii, J. R.; Kota, J.

    1985-01-01

    A quantitative comparison between theoretical predictions and observations of the intensity of galactic cosmic rays near the interplanetary current sheet is reported. Comparison of model calculations is made with a statistical analysis of observations of galactic cosmic rays at Earth and the simultaneous position of the current sheet. An ensemble of different current sheet inclinations is used, in order to make the analysis of the computations approximate the method used to analyses the data.

  15. Cosmic ray antimatter: Is it primary or secondary?

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

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

  16. Cosmic Ray Muons Timing in the ATLAS Detector

    SciTech Connect

    Meirose, Bernhard

    2009-12-17

    In this talk I discuss the use of calorimeter timing both for detector commissioning and in searches for new physics. In particular I present real and simulated cosmic ray muons data (2007) results for the ATLAS Tile Calorimeter system. The analysis shows that several detector errors such as imperfect calibrations can be uncovered. I also demonstrate the use of ATLAS Tile Calorimeter's excellent timing resolution in suppressing cosmic ray fake missing transverse energy (E{sub T}) in searches for supersymmetry.

  17. The effect of cosmic rays on thunderstorm electricity

    NASA Technical Reports Server (NTRS)

    Bragin, Y. A.

    1975-01-01

    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.

  18. First zonal harmonic component of cosmic ray neutron intensity

    NASA Technical Reports Server (NTRS)

    Takahashi, H.; Yahagi, N.; Chiba, T.

    1985-01-01

    Cosmic ray neutron data from the cosmic ray stations from the worldwide network in 1966, 1967 and 1969 are analyzed by means of the three dimensional analysis method by Nagashima. The variations of the north-south anisotropy, which is the first zonal harmonic component obtained from the analysis are studied. The result obtained confirms earlier findings. Relationship of the anisotropy to the interplanetary magnetic field sector polarity is also studied.

  19. Origin and composition of ultrahigh energy cosmic rays.

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1971-01-01

    Suggestion that, under certain circumstances, the absence of an apparent flattening of the ultrahigh energy cosmic ray spectrum at an energy level above 3 x 10 to the 18th power eV may have implications concerning the origin of ultrahigh energy cosmic rays (UECR). On the basis of the discussion presented, it seems that a heavy composition is indicated. It is therefore concluded that recent air-shower studies seem to indicate the resurrection of the galactic origin model.

  20. Detectors/Dosemeters of galactic and solar cosmic rays.

    PubMed

    Tommasino, L

    2004-01-01

    Different passive multidetector stacks have been developed at the Italian National Agency for Environmental Protection (ANPA-stack), which makes it possible to measure directly ionising radiations, low-energy and high-energy neutrons, and high-energy charged (HZE) particles. The stack consists of several types of passive devices, namely recoil-track and fission-track detectors, bubble detectors, thermoluminescence dosemeters and an electronic personal dosemeter. Most of these detectors have been used on earth for the assessment of the occupational exposure, or in outer space for cosmic ray physics and/or for the assessment of the dose received by astronauts. A great deal of efforts and new developments have been required to make these detectors useful for in-flight measurements. As outcome of these extensive efforts, different new detectors have been developed, which exploit some of the most successful principles of radiation detection, such as the use of avalanche processes to facilitate the registration of nuclear tracks and the use of coincidence-counting to increase the signal-to-noise ratio. On the basis of these new detectors, different systems (generally referred to as ANPA-stack) have been obtained, which have been successfully applied for a variety of different measurements of cosmic ray radiation fields and doses. PMID:15273355

  1. Development of Ultra High-Energy Cosmic Ray Research

    NASA Astrophysics Data System (ADS)

    Kampert, Karl-Heinz; Watson, Alan A.

    The discovery of extensive air showers by Rossi, Schmeiser, Bothe, Kolhörster and Auger at the end of the 1930s, facilitated by the coincidence technique of Bothe and Rossi, led to fundamental contributions in the field of cosmic ray physics and laid the foundation for high-energy particle physics. Soon after World War II a cosmic ray group at MIT in the USA pioneered detailed investigations of air shower phenomena and their experimental skill laid the foundation for many of the methods and much of the instrumentation used today. Soon interests focused to the highest energies requiring much larger detectors to be operated. The first detection of air fluorescence light by Japanese and US groups in the early 1970s marked an important experimental breakthrough towards this end as it allowed huge volumes of atmosphere to be monitored by optical telescopes. Radio observations of air showers, pioneered in the 1960s, are presently experiencing a renaissance and may revolutionise the field again. In the last 7 decades the research has seen many ups but also a few downs. However, the example of the Cygnus X-3 story demonstrated that even non-confirmable observations can have a huge impact by boosting new instrumentation to make discoveries and shape an entire scientific community.

  2. Industrial radiography with cosmic-ray muons: A progress report

    NASA Astrophysics Data System (ADS)

    Gilboy, W. B.; Jenneson, P. M.; Simons, S. J. R.; Stanley, S. J.; Rhodes, D.

    2007-09-01

    Cosmic-ray produced muons arrive at the surface of the earth with enormous energies ranging up to 1012 GeV. There have been sporadic attempts to exploit their extreme penetration through matter to probe the internal structures of very large objects, including an Egyptian pyramid and a volcano but their very low intensity per unit area ( ≈1 cm-2 per min) generally restricts the practicably attainable spatial resolution to large dimensions. Nevertheless the more intense low energy region of the muon spectrum has recently been shown to be capable of detecting high-Z objects with dimensions of the order of 10 cm hidden inside large transport containers in measurement times of minutes. These various developments have encouraged further studies of potential industrial uses of cosmic-ray muons in industrial applications. In order to gain maximum benefit from the low muon flux large area detectors are required and plastic scintillators offer useful advantages in size, cost and simplicity. Scintillator slabs up to 1 m2 square and 76.2 mm thick are undergoing testing for applications in the nuclear industry. The most direct approach employs photomultiplier tubes at each corner to measure the relative sizes of muon induced pulses to determine the location of each muon track passing through the scintillator. The performance of this technique is reported and its imaging potential is assessed.

  3. ROBAST: ROOT-based ray-tracing library for cosmic-ray telescopes

    NASA Astrophysics Data System (ADS)

    Okumura, Akira

    2016-03-01

    ROBAST (ROOT-based simulator for ray tracing) is a non-sequential ray-tracing simulation library developed for wide use in optical simulations of gamma-ray and cosmic-ray telescopes. The library is written in C++ and fully utilizes the geometry library of the ROOT analysis framework, and can build the complex optics geometries typically used in cosmic ray experiments and ground-based gamma-ray telescopes.

  4. The Quest for Cosmic Ray Protons in Galaxy Clusters

    NASA Astrophysics Data System (ADS)

    Pfrommer, C.; Enßlin, T. A.

    2004-12-01

    There have been many speculations about the presence of cosmic ray protons (CRps) in galaxy clusters over the past two decades. However, no direct evidence such as the characteristic γ-ray signature of decaying pions has been found so far. These pions would be a direct tracer of hadronic CRp interactions with the ambient thermal gas also yielding observable synchrotron and inverse Compton emission by additionally produced secondary electrons. The obvious question concerns the type of galaxy clusters most likely to yield a signal: Particularly suited sites should be cluster cooling cores due to their high gas and magnetic energy densities. We studied a nearby sample of clusters evincing cooling cores in order to place stringent limits on the cluster CRp population by using non-detections of EGRET. In this context, we examined the possibility of a hadronic origin of Coma-sized radio halos as well as radio mini-halos. Especially for mini-halos, strong clues are provided by the very plausible small amount of required CRp energy density and a matching radio profile. Introducing the hadronic minimum energy criterion, we show that the energetically favored CRp energy density is constrained to 2% ± 1% of the thermal energy density in Perseus. We also studied the CRp population within the cooling core region of Virgo using the TeV γ-ray detection of M 87 by HEGRA. Both the expected radial γ-ray profile and the required amount of CRp support this hadronic scenario.

  5. Ultra-heavy cosmic rays: Theoretical implications of recent observations

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

    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.

  6. SLOW DIFFUSION OF COSMIC RAYS AROUND A SUPERNOVA REMNANT

    SciTech Connect

    Fujita, Yutaka; Ohira, Yutaka; Takahara, Fumio

    2010-04-01

    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.

  7. Galactic cosmic-ray modulation near the heliopause

    SciTech Connect

    Guo, X.; Florinski, V.

    2014-09-20

    We investigate the modulation of galactic cosmic rays in the inner and outer heliosheaths using three-dimensional numerical simulations. The model is based on the Parker transport equation integrated using a stochastic phase-space trajectory method. Integration is performed on a plasma background obtained from a global three-dimensional magnetohydrodynamic simulations. Our results predict a negligible amount of modulation in the outer heliosheath because of weak scattering of cosmic ray ions owing to very low levels of magnetic fluctuation power at wavenumbers relevant to the transport of cosmic rays with MeV to GeV energies. This means that the heliopause may be treated as a Dirichlet-type boundary for the purpose of energetic particle modeling. We present models with and without drift velocity to facilitate comparison with papers published earlier. We also attempt to reproduce the sudden step-like increases of cosmic-ray intensity observed by Voyager 1 before its encounter with the heliopause. Our results indicate that very slow cross-field diffusion in the outer heliosheath could produce a large gradient of cosmic rays inside the heliospheric boundary. The resulting large gradient in cosmic-ray intensity near the heliopause qualitatively agrees with recent Voyager 1 observations.

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

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

    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.

  9. Common origin of the high energy astronomical gamma rays, neutrinos and cosmic ray positrons?

    NASA Astrophysics Data System (ADS)

    Dado, Shlomo; Dar, Arnon

    2016-03-01

    We show that the observed fluxes, spectra and sky distributions of the high energy astronomical neutrinos, gamma rays and cosmic ray positrons satisfy the simple relations expected from their common production in hadronic collisions in/near source of high energy cosmic rays with diffuse matter.

  10. Search for correlations between the arrival directions of IceCube neutrino events and ultrahigh-energy cosmic rays detected by the Pierre Auger Observatory and the Telescope Array

    DOE PAGESBeta

    Aartsen, M. G.

    2016-01-20

    This study presents the results of different searches for correlations between very high-energy neutrino candidates detected by IceCube and the highest-energy cosmic rays measured by the Pierre Auger Observatory and the Telescope Array. We first consider samples of cascade neutrino events and of high-energy neutrino-induced muon tracks, which provided evidence for a neutrino flux of astrophysical origin, and study their cross-correlation with the ultrahigh-energy cosmic ray (UHECR) samples as a function of angular separation. We also study their possible directional correlations using a likelihood method stacking the neutrino arrival directions and adopting different assumptions on the size of the UHECRmore » magnetic deflections. Finally, we perform another likelihood analysis stacking the UHECR directions and using a sample of through-going muon tracks optimized for neutrino point-source searches with sub-degree angular resolution. No indications of correlations at discovery level are obtained for any of the searches performed. The smallest of the p-values comes from the search for correlation between UHECRs with IceCube high-energy cascades, a result that should continue to be monitored.« less

  11. Search for correlations between the arrival directions of IceCube neutrino events and ultrahigh-energy cosmic rays detected by the Pierre Auger Observatory and the Telescope Array

    NASA Astrophysics Data System (ADS)

    IceCube Collaboration; Pierre Auger Collaboration; Telescope Array Collaboration

    2016-01-01

    This paper presents the results of different searches for correlations between very high-energy neutrino candidates detected by IceCube and the highest-energy cosmic rays measured by the Pierre Auger Observatory and the Telescope Array. We first consider samples of cascade neutrino events and of high-energy neutrino-induced muon tracks, which provided evidence for a neutrino flux of astrophysical origin, and study their cross-correlation with the ultrahigh-energy cosmic ray (UHECR) samples as a function of angular separation. We also study their possible directional correlations using a likelihood method stacking the neutrino arrival directions and adopting different assumptions on the size of the UHECR magnetic deflections. Finally, we perform another likelihood analysis stacking the UHECR directions and using a sample of through-going muon tracks optimized for neutrino point-source searches with sub-degree angular resolution. No indications of correlations at discovery level are obtained for any of the searches performed. The smallest of the p-values comes from the search for correlation between UHECRs with IceCube high-energy cascades, a result that should continue to be monitored.

  12. Separation of the electron and proton cosmic-ray components by means of a calorimeter in the PAMELA satellite-borne experiment for the case of particle detection within a large aperture

    SciTech Connect

    Karelin, A. V. Borisov, S. V.; Voronov, S. A.; Malakhov, V. V.

    2013-06-15

    The PAMELA satellite-borne experiment is designed to study cosmic rays over a broad energy range. The apparatus has been in near-Earth cosmic space from June 2006 to the present time. It is equipped with a magnetic spectrometer for determining the sign of the particle charge and rigidity. In solving some problems, however, information from the magnetic spectrometer becomes inaccessible, so that it is necessary to employ a calorimeter to separate the electron and nuclear cosmic-ray components. A procedure for separating these components for particles arriving off the magnetic-spectrometer aperture is considered.

  13. 100 years since the discovery of cosmic rays. A brief history

    NASA Astrophysics Data System (ADS)

    Chiavassa, Andrea

    2012-11-01

    With the words "Cosmic Rays" we mean particles impinging on the earth atmosphere. The existence of these particles was discovered in 1912, i.e. exactly 100 years ago, by the Austrian physicist Victor Hesss. In this contribution I will describe the steps that lead to such a discovery: from the electroscope measurements, showing their spontaneous discharge, to the correct explanation of this results with the existence of charged particles arriving from outside of the atmosphere. Then I will discuss the first steps of experimental particle physics, obtained with experiments performed detecting cosmic rays, that allowed important discoveries as the detection of antimatter and of new subatominc particles as muons and pions.

  14. Propagation of Cosmic Rays: Nuclear Physics in Cosmic-ray Studies

    NASA Technical Reports Server (NTRS)

    Moskalenko, Igor V.; Strong, Andrew W.; Mashnik, Stepan G.

    2004-01-01

    The nuclei fraction in cosmic rays (CR) far exceeds the fraction of other CR species, such as antiprotons, electrons, and positrons. Thus the majority of information obtained from CR studies is based on interpretation of isotopic abundances using CR propagation models where the nuclear data and isotopic production cross sections in p- and alpha-induced reactions are the key elements. This paper presents an introduction to the astrophysics of CR and diffuse gamma-rays and dimsses some of the puzzles that have emerged recently due to more precise data and improved propagation models. Merging with cosmology and particle physics, astrophysics of CR has become a very dynamic field with a large potential of breakthrough and discoveries in the near fume. Exploiting the data collected by the CR experiments to the fullest requires accurate nuclear cross sections.

  15. Propagation of Cosmic Rays: Nuclear Physics in Cosmic-Ray Studies

    SciTech Connect

    Moskalenko, Igor V.; Mashnik, Stepan G.

    2005-05-24

    The nuclei fraction in cosmic rays (CR) far exceeds the fraction of other CR species, such as antiprotons, electrons, and positrons. Thus the majority of information obtained from CR studies is based on interpretation of isotopic abundances using CR propagation models where the nuclear data and isotopic production cross sections in p- and {alpha}-induced reactions are the key elements. This paper presents an introduction to the astrophysics of CR and diffuse {gamma}-rays and discusses some of the puzzles that have emerged recently due to more precise data and improved propagation models. Merging with cosmology and particle physics, astrophysics of CR has become a very dynamic field with a large potential of breakthrough and discoveries in the near future. Exploiting the data collected by the CR experiments to the fullest requires accurate nuclear cross sections.

  16. PAMELA measurements of cosmic-ray proton and helium spectra.

    PubMed

    Adriani, O; Barbarino, G C; Bazilevskaya, G A; Bellotti, R; Boezio, M; Bogomolov, E A; Bonechi, L; Bongi, M; Bonvicini, V; Borisov, S; Bottai, S; Bruno, A; Cafagna, F; Campana, D; Carbone, R; Carlson, P; Casolino, M; Castellini, G; Consiglio, L; De Pascale, M P; De Santis, C; De Simone, N; Di Felice, V; Galper, A M; Gillard, W; Grishantseva, L; Jerse, G; Karelin, A V; Koldashov, S V; Krutkov, S Y; Kvashnin, A N; Leonov, A; Malakhov, V; Malvezzi, V; Marcelli, L; Mayorov, A G; Menn, W; Mikhailov, V V; Mocchiutti, E; Monaco, A; Mori, N; Nikonov, N; Osteria, G; Palma, F; Papini, P; Pearce, M; Picozza, P; Pizzolotto, C; Ricci, M; Ricciarini, S B; Rossetto, L; Sarkar, R; Simon, M; Sparvoli, R; Spillantini, P; Stozhkov, Y I; Vacchi, A; Vannuccini, E; Vasilyev, G; Voronov, S A; Yurkin, Y T; Wu, J; Zampa, G; Zampa, N; Zverev, V G

    2011-04-01

    Protons and helium nuclei are the most abundant components of the cosmic radiation. Precise measurements of their fluxes are needed to understand the acceleration and subsequent propagation of cosmic rays in our Galaxy. We report precision measurements of the proton and helium spectra in the rigidity range 1 gigavolt to 1.2 teravolts performed by the satellite-borne experiment PAMELA (payload for antimatter matter exploration and light-nuclei astrophysics). We find that the spectral shapes of these two species are different and cannot be described well by a single power law. These data challenge the current paradigm of cosmic-ray acceleration in supernova remnants followed by diffusive propagation in the Galaxy. More complex processes of acceleration and propagation of cosmic rays are required to explain the spectral structures observed in our data. PMID:21385721

  17. Cosmic-ray record in solar system matter

    NASA Technical Reports Server (NTRS)

    Reedy, R. C.; Arnold, J. R.; Lal, D.

    1983-01-01

    The interaction of galactic cosmic rays (GCR) and solar cosmic rays (SCR) with bodies in the solar system is discussed, and what the record of that interaction reveals about the history of the solar system is considered. The influence of the energy, charge, and mass of the particles on the interaction is addressed, showing long-term average fluxes of solar protons, predicted production rates for heavy-nuclei tracks and various radionuclides as a function of depth in lunar rock, and integral fluxes of protons emitted by solar flares. The variation of the earth's magnetic field, the gardening of the lunar surface, and the source of meteorites and cosmic dust are studied using the cosmic ray record. The time variation of GCR, SCR, and VH and VVH nuclei is discussed for both the short and the long term.

  18. Cosmic Ray Studies with the Fermi Gamma-ray Space Telescope Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Thompson, D. J.; Baldini, L.; Uchiyama, Y.

    2011-01-01

    The Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope provides both direct and indirect measurements of Galactic cosmic rays (CR). The LAT high-statistics observations of the 7 GeV - 1 TcV electron plus positron spectrum and limits on spatial anisotropy constrain models for this cosmic-ray component. On a Galactic scale, the LAT observations indicate that cosmic-ray sources may be more plentiful in the outer Galaxy than expected or that the scale height of the cosmic-ray diffusive halo is larger than conventional models. Production of cosmic rays in supernova remnants (SNR) is supported by the LAT gamma-ray studies of several of these, both young SNR and those interacting with molecular clouds.

  19. Cosmic Ray Studies with the Fermi Gamma-ray Space Telescope Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Thompson, David J.; Baldini, L.; Uchiyama, Y.

    2012-01-01

    The Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope provides both direct and indirect measurements of galactic cosmic rays (CR). The LAT high-statistics observations of the 7 GeV - 1 TeV electron plus positron spectrum and limits on spatial anisotropy constrain models for this cosmic-ray component. On a galactic scale, the LAT observations indicate that cosmic-ray sources may be more plentiful in the outer Galaxy than expected or that the scale height of the cosmic-ray diffusive halo is larger than conventional models. Production of cosmic rays in supernova remnants (SNR) is supported by the LAT gamma-ray studies of several of these, both young SNR and those interacting with molecular clouds.

  20. Ionization and heating by X-rays and cosmic rays

    NASA Astrophysics Data System (ADS)

    Güdel, Manuel

    2015-09-01

    High-energy radiation from the central T Tauri and protostars plays an important role in shaping protoplanetary disks and influences their evolution. Such radiation, in particular X-rays and extreme-ultraviolet (EUV) radiation, is predominantly generated in unstable stellar magnetic fields (e.g., the stellar corona), but also in accretion hot spots. Even jets may produce X-ray emission. Cosmic rays, i.e., high-energy particles either from the interstellar space or from the star itself, are of crucial importance. Both highenergy photons and particles ionize disk gas and lead to heating. Ionization and heating subsequently drive chemical networks, and the products of these processes are accessible through observations of molecular line emission. Furthermore, ionization supports the magnetorotational instability and therefore drives disk accretion, while heating of the disk surface layers induces photoevaporative flows. Both processes are crucial for the dispersal of protoplanetary disks and therefore critical for the time scales of planet formation. This chapter introduces the basic physics of ionization and heating starting from a quantum mechanical viewpoint, then discusses relevant processes in astrophysical gases and their applications to protoplanetary disks, and finally summarizes some properties of the most important high-energy sources for protoplanetary disks. 14th Lecture from Summer School "Protoplanetary Disks: Theory and Modelling Meet Observations"