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Sample records for cosmic ray isotope

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Isotopic Composition of Cosmic Rays:. Results from the Cosmic Ray Isotope Spectrometer on the Ace Spacecraft

    NASA Astrophysics Data System (ADS)

    Israel, M. H.

    Over the past seven years the Cosmic Ray Isotope Spectrometer (CRIS) on the ACE spacecraft has returned data with an unprecedented combination of excellent mass resolution and high statistics, describing the isotopic composition of elements from lithium through nickel in the energy interval ~ 50 to 500 MeV/nucleon. These data have demonstrated: * The time between nucleosynthesis and acceleration of the cosmic-ray nuclei is at least 105 years. The supernova in which nucleosynthesis takes place is thus not the same supernova that accelerates a heavy nucleus to cosmic-ray energy. * The mean confinement time of cosmic rays in the Galaxy is 15 Myr. * The isotopic composition of the cosmic-ray source is remarkably similar to that of solar system. The deviations that are observed, particularly at 22Ne and 58Fe, are consistent with a model in which the cosmic-ray source is OB associations in which the interstellar medium has solar-system composition enriched by roughly 20% admixture of ejecta from Wolf-Rayet stars and supernovae. * Cosmic-ray secondaries that decay only by electron capture provide direct evidence for energy loss of cosmic rays as they penetrate the solar system. This invited overview paper at ECRS 19 was largely the same as an invited paper presented a month earlier at the 8th Nuclei in the Cosmos Conference in Vancouver. The proceedings of that conference will be published shortly by Elsevier as a special edition of Nuclear Physics A. For further summary of results from CRIS, the reader is referred to URL <> and links on that page to CRIS and to Science News.

  8. A large area experiment to determine cosmic ray isotopic abundances

    NASA Technical Reports Server (NTRS)

    Mauger, B. G.; Balasubrahmanyan, V. K.; Ormes, J. F.; Streitmatter, R. E.; Heinrich, W.; Simon, M.; Tittel, H. O.

    1983-01-01

    Measurements of the isotopic composition of cosmic rays have shown that the cosmic ray isotope ratios, Ne-22/Ne-20 and (Mg-25 + Mg-26)/Mg-24, exceed the solar abundance ratios by factors of 2.7 and 1.8, respectively. There are several processes which could be responsible for the observed excess of neutron-rich isotopes. The considered models imply neutron enrichment in the case of other, less abundant species, and a measurement of the involved isotopic abundances could provide a basis for the determination of the dominating processes occurring in cosmic ray sources. However, an experiment utilizing special equipment is necessary to conduct the required measurements. Such an experiment, the Aluminum Isotopic Composition Experiment (Alice), is being designed in a joint effort involving NASA and a West German university. Alice uses a Cherenkov-range technique to determine the isotopic composition of elements from oxygen through argon.

  9. 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.

  10. 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.

  11. Regolith history from cosmic-ray-produced isotopes

    NASA Technical Reports Server (NTRS)

    Fireman, E. L.

    1974-01-01

    A statistical model is given for soil development relating meteoroid impacts on the moon to cosmic-ray-produced isotopes in the soil. By means of this model, the average lunar mass loss rate during the past 1.4 aeons is determined to be 170g/sq cm aeon and the soil mixing rate to be approximately 200 cm/aeon from the gadolinium isotope data for the Apollo 15 and 16 drill stems. The isotope data also restrict the time variation of the meteoroid flux during the past 1.4 aeons.

  12. The elemental and isotopic composition of galactic cosmic ray nuclei

    NASA Technical Reports Server (NTRS)

    Mewaldt, R. A.

    1983-01-01

    A directly accessible sample of matter which originates outside the solar system is provided by galactic cosmic rays. The present investigation is primarily concerned with progress related to questions raised regarding the similarity or difference between solar system matter and matter coming from outside the solar system. The investigation takes into account U.S. contributions to this topic over the period from 1979 to 1982. The cosmic ray (CR) abundances of all the elements from H to Ni (atomic number Z=1 to 28) have now been measured. Cosmic ray source (CRS) and solar system (SS) elemental compositions are listed in a table, and the ratio of CRS to SS abundance for 21 elements is shown in a graph. There is now clear evidence from CR isotope studies that the nucleosynthesis of CRS material has differed from that of SS material.

  13. Isotopic anomalies in the galactic cosmic-ray source

    NASA Technical Reports Server (NTRS)

    Wiedenbeck, M. E.; Greiner, D. E.

    1981-01-01

    Observations of the isotopic compositions of oxygen, neon and magnesium nuclei in galactic cosmic rays are presented and discussed in terms of nucleosynthesis at the galactic cosmic ray source. The observations, made with a charged-particle telescope carried aboard ISEE-3, show enhancements in the Ne-22/Ne-20, Mg-25/Mg-24 and Mg-26/Mg-24 ratios with respect to solar system abundances by factors of 4.1, 1.6 and 1.6, respectively. The data thus demonstrate that the galactic cosmic ray source is compositionally distinct from the solar system, and also rule out the models of Woolsey and Weaver (in press) for the synthesis of excess Ne-22 and a model of normal star formation, evolution and mass loss in a region enriched in metals.

  14. The isotopes of neon in the galactic cosmic rays

    NASA Technical Reports Server (NTRS)

    Garcia-Munoz, M.; Simpson, J. A.; Wefel, J. P.

    1979-01-01

    The paper examines the results obtained by the University of Chicago instrument on board the IMP 7 satellite used to measure the abundances of Ne-20 and Ne-22 in the galactic cosmic rays during 1973-1977, over the general energy range of 60-230 MeV per nucleon. It is reported that the instrument shows a mass resolution of 0.7 amu(sigma) which was confirmed by calibrating a backup instrument at the LBL Bevalac with separated beams of neon isotopes. Through the use of standard solar modulation and cosmic-ray propagation models, the cosmic-ray source ratio inferred is Ne-22/Ne-20 = 0.38 = or -0.07 which is significantly greater than the present solar system ratio. It is concluded that propagation effects or cross-section uncertainties cannot account for such a large abundance of Ne-22, and thus this measurement provides evidence that the cosmic rays come from a source region where the Ne-22 abundance is substantially greater than in solar system material.

  15. Time variations of cosmic-ray helium isotopes

    NASA Astrophysics Data System (ADS)

    Picot-Clemente, Nicolas

    2013-04-01

    The Balloon-born Experiment with Superconducting magnet Spectrometer (BESS) is a Japan-U.S. program that carried out 11 successful flights from 1993 to 2007. The BESS instrument includes various particle detectors, such as plastic scintillator hodoscopes and a central jet-type drift chamber surrounded by a superconducting solenoid magnet. Measurements provided by these detectors allow precise identification of cosmic-ray helium isotopes. The long-duration flight of the BESS-Polar I instrument, about 8.5 days over Antarctica in 2004, allows measurements of time variations of isotope fluxes for the first time. The time variation of the helium isotope flux is presented for rigidities from 1.2 GV to 2.5 GV, and the results are compared with previously reported proton data and neutron monitor data.

  16. The isotopic composition of iron-group cosmic rays

    NASA Technical Reports Server (NTRS)

    Leske, Richard A.; Milliken, Barrett; Wiedenbeck, Mark E.

    1992-01-01

    Measurements are reported of the relative abundances of Mn, Fe, Co, and Ni isotopes in Galactic cosmic rays with energies of about 325 MeV per nucleon. The observed limit (Mn-54)/(Mn-53) of less than 0.25 is significantly less than the value of about 0.8-0.9 expected if Mn-54 were stable, indicating that most of the Mn-54 produced during cosmic-ray propagation in the Galaxy has undergone radioactive decay. Relative source abundances of iron and nickel isotopes, and in particular the ratio (Fe-54)/(Fe-56) = 0.046 +/- 0.020, are generally consistent with solar system values. One exception is the source ratio (Ni-60)/(Ni-58) for which an enhancement by a factor of 2.8 +/- 1.0 over the solar value is found. The isotope (Co-59) is found to make up a sizable fraction of the observed Co, indicating a time delay more than about 100,000 yr between nucleosynthesis and acceleration if this nuclide is synthesized as (Cu-59) or (Ni-59).

  17. Study of Cosmic Ray H and He Isotopes

    NASA Astrophysics Data System (ADS)

    Picot-Clemente, Nicolas

    This proposal requests a support for analysis and interpretation of H and He isotope data from the last Antarctic balloon flight of the Balloon-borne Experiment with a Superconducting Spectrometer (BESS-Polar II). The isotopes 2H and 3He in the cosmic radiation are mainly secondary products from the p-p and p-4He interactions of primary cosmic rays in the interstellar medium. Other reactions such as 4He - 4He and p-(Z>3) contribute to a lesser extent to the production of 2H and 3He, as well as antiprotons. In the past most isotope measurements have been limited by statistics and mass resolution. BESS-Polar II flew for 24.5 days over Antarctica in 2007-2008. It recorded 4.7 billion events, about 5 times events collected with the prior BESS-Polar I. The BESS-Polar II data offer a unique opportunity to identify and precisely measure H and He isotopes over a wide rigidity range, 0.5 GV to 4 GV. The BESS instrument has many outstanding hardware features, which enable precise measurements of cosmic-ray H, He, and their isotopes, in addition to antiparticles. Its long-duration-balloon flight drastically reduced statistical uncertainties, and it provides the most precise measurements of H and He isotope fluxes and secondary-to-primary ratios. The unprecedented precision of BESSPolar II measurements together with other cosmic-ray data, can strongly constrain propagation models and their parameters. It also facilitates a sensitive study of cosmicray time variations, which contribute to our understanding of local conditions in the Heliosphere as well as modeling of particle fluxes and plasma conditions in the nearEarth environment. The long duration of the BESS-Polar II flight and stability of its detectors enable the study of transient time variations of hydrogen and helium isotope fluxes. Measurements of 2H and 3He isotopes along with their main parents 1H and 4He provide important information on both the Galactic and heliospheric propagation of cosmic rays, as well as a

  18. The isotopic composition of iron-group galactic cosmic rays

    NASA Technical Reports Server (NTRS)

    Wiedenbeck, M. E.; Leske, R. A.

    1995-01-01

    Results from studies of the isotopic composition of iron group elements in the galactic cosmic radiation are reviewed, emphasizing recently reported measurements from the ISEE-3 spacecraft. The observed isotope distributions for the elements Ti through Mn are in good agreement with those expected for a propagated solar-like source composition, with the possible exception of an enhanced abundance of Ti-50. It is found that a significant fraction of the radioactive secondary nuclide Mn-54 has decayed, indicating a confinement time of iron group cosmic rays in the galaxy of at least 2 Myr. The source ratio Fe-54/Fe-56 is found to be consistent with the solar value, but the ratio Ni-60/Ni-58 is greater than solar by a factor of 2.8+/-1.0. The measured abundance of Co-59 is significantly greater than the calculated secondary contribution, suggesting that this nuclide has been produced in the source regions by the electron capture decay of Ni-59 and implying a time delay between nucleosynthesis and acceleration approximately greater than 10(exp 5) yr.

  19. Cosmic rays interaction with comets and its impact on cometary isotopic and chemical composition

    NASA Astrophysics Data System (ADS)

    Gronoff, G.; Maggiolo, R.; Mertens, C. J.; Airapetian, V.; De Keyser, J.; Cessateur, G.; Dhooghe, F.; Gunell, H.

    2015-12-01

    Comets contain the most pristine material in the solar system. However, since their formation ~4.5 Gy ago, they have been altered by cosmic rays. The galactic and solar cosmic rays have a broad spectrum of energies and interact with the cometary surface and subsurface. While low energy cosmic rays interact only with the cometary surface, the most energetic cosmic rays deposit significant amount of energy down to tens of meters. This interaction can modify the isotopic ratio in cometary ices and create secondary compounds through radiolysis. We perform a theoretical analysis of the effect of cosmic rays on cometary material. We modeled the energy deposition of cosmic ray as a function of depth using a Geant4 applicationmodified to take into account the isotope creation process. We analyze the consequences of the energy deposition on the isotopic and chemical composition of cometary ices and discuss their implication on the interpretation of cometary observations.

  20. 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.

  1. New Measurements of the Li, Be, and B Isotopes as a Test of Cosmic Ray Transport Models

    NASA Technical Reports Server (NTRS)

    deNolfo, Georgia A.; Yanasak, N. E.; Binns, W. R.; Cummings, A. C.; Davis, A. J.; George, J. S.; Hink, P. L.; Israel, M. H.; Leske, R. A.; Mewaldt, R. A.

    2003-01-01

    Precise measurements of predominantly secondary cosmic-ray Li, Be, and B together with current well-measured production cross-sections for these isotopes help to improve our understanding of galactic cosmic ray propagation models. The Cosmic Ray Isotope Spectrometer (CRIS) on ACE has been measuring isotopic composition of cosmic rays since 1997 with high statistical precision. We present the isotopic abundances from CRIS and discuss these observations in the context of cosmic-ray transport models and previous cosmic-ray measurements.

  2. A review and interpretation of recent cosmic ray beryllium isotope measurements

    NASA Technical Reports Server (NTRS)

    Buffington, A.

    1978-01-01

    Beryllium-10 is of interest for cosmic ray propagation, because its radioactive decay half-life is well matched to the expected cosmic ray age. Recent beryllium isotope measurements from satellites and balloon covered an energy range from about 30 to 300 MeV/nucleon. At the lowest energies, most of the Be-10 is absent, indicating a cosmic ray lifetime of order 2 x 10 to the 7th power years and the rather low average density of 0.2 atoms/cc traversed by the cosmic rays. At higher energies, a greater propagation of Be-10 is observed, indicating a somewhat shorter lifetime. These experiments will be reviewed and then compared with a new experiment covering from 100 to 1000 MeV/nucleon. Although improved experiments will be necessary to realize the full potential of cosmic ray beryllium isotope measurements, these first results are already disclosing interesting and unexpected facts about cosmic ray acceleration and propagation.

  3. High resolution measurements of galactic cosmic-ray neon, magnesium, and silicon isotopes

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

    High-resolution measurements of the abundances of individual isotopes of neon, magnesium and silicon in galactic cosmic rays are reported. The Caltech Heavy Isotope Spectrometer Telescope on board the ISEE 3 spacecraft was used to obtain measurements in the range 30 to 180 MeV/n at an rms mass resolution of 0.20 amu. Results indicate excesses of Ne-22 as well as Mg-25 and Mg-26 in galactic cosmic rays with respect to their solar system abundances. Calculations of the effects of interstellar propagation and solar modulation on cosmic-ray isotope abundances also imply an Mg-25 + Mg-26 cosmic ray source fraction significantly greater than the solar system fraction, and it is suggested that the cosmic ray source material and solar system material were synthesized under different conditions.

  4. The isotopic composition of neon and magnesium in the low energy cosmic rays

    NASA Technical Reports Server (NTRS)

    Garcia-Munoz, M.; Simpson, J. A.; Wefel, J. P.

    1980-01-01

    The ratios Ne-22/Ne-20 and Mg-26/Mg-24 were measured in galactic cosmic rays by the IMP-7 satellite in the 60 to 230 MeV/nucleon range. The neon cosmic ray source ratio Ne-22/Ne-20 is about 0.38, which is much larger than the current solar system relationship; the Mg data agrees with the solar system isotopic ratio of 0.14 at the cosmic ray source. The Ne and Mg source ratios are explained by supernova models, and become a new constraint which should be satisfied by any model of cosmic ray origin.

  5. Isotopes of cosmic ray elements from neon to nickel

    NASA Technical Reports Server (NTRS)

    Waddington, C. J.; Freier, P. S.; Fickle, R. K.; Brewster, N. R.

    1981-01-01

    Results obtained from a balloon exposure of a cosmic ray detector flown in 1977 are reported. The charge resolution ranged from 0.19 to 0.21 charge units between neon and nickel and the mass resolution for nuclei stopped in the emulsions ranged from 0.40 to 0.70 amu for A between 20 and 60 amu. This was enough to correctly identify almost all nuclei, but not to uniquely resolve neighboring mass peaks. Both Ne and Mg show evidence for neutron enrichment relative to the solar system abundance. Si and S are consistent with solar abundances, while Ar has no significant source abundances. P, Cl and K have essentially no primary component and the isotopic distribution observed is quite consistent with that expected from propagation. An excess of Ca-44 at the source is shown, indicating high metallicity in the source. The abundance of Fe-58 is nine percent or less, and Ni shows a one-to-one ratio for Ni-58 to 60, implying intermediate metallicity.

  6. 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)

  7. 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)

  8. Experiments to study cosmic ray isotopic composition up to sub 40 Zr

    SciTech Connect

    Milliken, B. )

    1990-03-20

    Instruments being currently developed for balloon-borne cosmic ray isotopic composition measurements should lead to instruments with the precise mass resolution and large geometry factor needed to study isotopes in the range 30{le}{ital Z}{le}40 with long duration exposure on a polar orbiting platform or on the moon.

  9. BESS-Polar II Hydrogen and Helium Isotope Measurements to Constrain Cosmic-Ray Propagation Models

    NASA Astrophysics Data System (ADS)

    Picot-Clemente, Nicolas; BESS-Polar Collaboration

    2017-01-01

    The Balloon-borne Experiment with Superconducting Spectrometer BESS-Polar II flew over Antarctica for 24.5 days from December 2007 through January 2008, during the 23rd solar cycle minimum. The instrument is made of complementary particle detectors which allow to precisely measure the charge, velocity and rigidity of incoming cosmic rays. It can accurately separate cosmic-ray hydrogen and helium isotopes from 0.2 to 1.5 GeV/nucleon. Flux and secondary-to-primary ratios of these particles can bring important information to better understand the cosmic-ray propagation history in the Galaxy. BESS-Polar II provides the most precise isotope measurements to date between 0.2 and 1.5 GeV/nucleon. These data will be reported and constraints on cosmic-ray propagation models, using the GALPROP program, will be discussed.

  10. The isotopic composition of galactic cosmic-ray lithium, beryllium, and boron

    NASA Technical Reports Server (NTRS)

    Garcia-Munoz, M.; Mason, G. M.; Simpson, J. A.

    1975-01-01

    The isotopes of cosmic-ray Li, Be, and B near 100 MeV per nucleon have been measured with cosmic-ray telescopes on board the IMP-7 and IMP-8 satellites during 1973 and 1974. The measured isotopic abundances provide a stringent test for models of interstellar propagation and solar modulation. It is found that the isotopic abundances can be explained using a steady-state interstellar propagation model with a 5-g/sq cm leakage mean free path. These results, taken along with Be-10 abundance measurements, indicate a longer lifetime for cosmic rays than that predicted by the usual assumption of an average interstellar density of 1 to 3 atoms per cu cm.

  11. The charge and isotopic composition of Z = 6-14 cosmic ray nuclei at their source

    NASA Technical Reports Server (NTRS)

    Webber, W. R.

    1982-01-01

    Using data from a cosmic ray charge-isotope telescope flown on balloons, both the charge and isotopic composition are determined of Z = 6-14 cosmic ray nuclei. A low abundance for the elements N and Ne in the cosmic ray source relative to solar cosmic rays is observed. For the isotopes, a cosmic ray source ratio Ne-22/Ne-20 is found that is 3.52 plus or minus 0.67 times the solar ratio, this enhancement being due in part to an enhancement of Ne-22 and in part to an underabundance of Ne-20. Also observed are possible enhancements of the Mg-26/Mg-24 ratio, which is 1.40 plus or minus 0.24 times the solar t ratio, and the C-13/C-12 ratio, which is 2.90 plus or minus 0.93 times the solar ratio. For Ne, the underabundance of this element, coupled with the overabundnace of the isotope Ne-22, is seen as providing an important new clue to the nucleosynthesis processes producing these differences.

  12. Isotopic Composition of Light Nuclei in Cosmic Rays: Results from AMS-01

    NASA Astrophysics Data System (ADS)

    Aguilar, M.; Alcaraz, J.; Allaby, J.; Alpat, B.; Ambrosi, G.; Anderhub, H.; Ao, L.; Arefiev, A.; Arruda, L.; Azzarello, P.; Basile, M.; Barao, F.; Barreira, G.; Bartoloni, A.; Battiston, R.; Becker, R.; Becker, U.; Bellagamba, L.; Berdugo, J.; Berges, P.; Bertucci, B.; Biland, A.; Bindi, V.; Boella, G.; Boschini, M.; Bourquin, M.; Bruni, G.; Buénerd, M.; Burger, J. D.; Burger, W. J.; Cai, X. D.; Cannarsa, P.; Capell, M.; Casadei, D.; Casaus, J.; Castellini, G.; Cernuda, I.; Chang, Y. H.; Chen, H. F.; Chen, H. S.; Chen, Z. G.; Chernoplekov, N. A.; Chiueh, T. H.; Choi, Y. Y.; Cindolo, F.; Commichau, V.; Contin, A.; Cortina-Gil, E.; Crespo, D.; Cristinziani, M.; Dai, T. S.; dela Guia, C.; Delgado, C.; Di Falco, S.; Djambazov, L.; D'Antone, I.; Dong, Z. R.; Duranti, M.; Engelberg, J.; Eppling, F. J.; Eronen, T.; Extermann, P.; Favier, J.; Fiandrini, E.; Fisher, P. H.; Flügge, G.; Fouque, N.; Galaktionov, Y.; Gervasi, M.; Giovacchini, F.; Giusti, P.; Grandi, D.; Grimm, O.; Gu, W. Q.; Haino, S.; Hangarter, K.; Hasan, A.; Hermel, V.; Hofer, H.; Hungerford, W.; Ionica, M.; Jongmanns, M.; Karlamaa, K.; Karpinski, W.; Kenney, G.; Kim, D. H.; Kim, G. N.; Kim, K. S.; Kirn, T.; Klimentov, A.; Kossakowski, R.; Kounine, A.; Koutsenko, V.; Kraeber, M.; Laborie, G.; Laitinen, T.; Lamanna, G.; Laurenti, G.; Lebedev, A.; Lechanoine-Leluc, C.; Lee, M. W.; Lee, S. C.; Levi, G.; Lin, C. H.; Liu, H. T.; Lu, G.; Lu, Y. S.; Lübelsmeyer, K.; Luckey, D.; Lustermann, W.; Maña, C.; Margotti, A.; Mayet, F.; McNeil, R. R.; Menichelli, M.; Mihul, A.; Mujunen, A.; Natale, S.; Oliva, A.; Palmonari, F.; Paniccia, M.; Park, H. B.; Park, W. H.; Pauluzzi, M.; Pauss, F.; Pereira, R.; Perrin, E.; Pevsner, A.; Pilo, F.; Pimenta, M.; Plyaskin, V.; Pojidaev, V.; Pohl, M.; Produit, N.; Quadrani, L.; Rancoita, P. G.; Rapin, D.; Ren, D.; Ren, Z.; Ribordy, M.; Riihonen, E.; Ritakari, J.; Ro, S.; Roeser, U.; Sagdeev, R.; Santos, D.; Sartorelli, G.; Saouter, P.; Sbarra, C.; Schael, S.; Schultz von Dratzig, A.; Schwering, G.; Seo, E. S.; Shin, J. W.; Shoumilov, E.; Shoutko, V.; Siedenburg, T.; Siedling, R.; Son, D.; Song, T.; Spada, F. R.; Spinella, F.; Steuer, M.; Sun, G. S.; Suter, H.; Tang, X. W.; Ting, Samuel C. C.; Ting, S. M.; Tomassetti, N.; Tornikoski, M.; Torsti, J.; Trümper, J.; Ulbricht, J.; Urpo, S.; Valtonen, E.; Vandenhirtz, J.; Velikhov, E.; Verlaat, B.; Vetlitsky, I.; Vezzu, F.; Vialle, J. P.; Viertel, G.; Vité, D.; Von Gunten, H.; Waldmeier Wicki, S.; Wallraff, W.; Wang, J. Z.; Wiik, K.; Williams, C.; Wu, S. X.; Xia, P. C.; Xu, S.; Xu, Z. Z.; Yan, J. L.; Yan, L. G.; Yang, C. G.; Yang, J.; Yang, M.; Ye, S. W.; Zhang, H. Y.; Zhang, Z. P.; Zhao, D. X.; Zhou, F.; Zhou, Y.; Zhu, G. Y.; Zhu, W. Z.; Zhuang, H. L.; Zichichi, A.; Zimmermann, B.; Zuccon, P.

    2011-08-01

    The variety of isotopes in cosmic rays allows us to study different aspects of the processes that cosmic rays undergo between the time they are produced and the time of their arrival in the heliosphere. In this paper, we present measurements of the isotopic ratios 2H/4He, 3He/4He, 6Li/7Li, 7Be/(9Be+10Be), and 10B/11B in the range 0.2-1.4 GeV of kinetic energy per nucleon. The measurements are based on the data collected by the Alpha Magnetic Spectrometer, AMS-01, during the STS-91 flight in 1998 June.

  13. The abundance of the radioactive isotope Al-26 in galactic cosmic rays

    NASA Technical Reports Server (NTRS)

    Wiedenbeck, M. E.

    1983-01-01

    Satellite observations of the isotopic composition of aluminum in low energy cosmic rays (E/M = 200 MeV/amu) have been used to determine the abundance of the unstable isotope Al-26 (T1/2 = 0.87 Myr). The observed abundance ratio, Al-26/Al-27 = 0.036 (+0.037, -0.022), is in good agreement with previous balloon observations and yields a cosmic ray confinement time consistent with values based on the abundance of Be-10.

  14. The isotopic composition of galactic cosmic ray lithium, beryllium and boron

    NASA Technical Reports Server (NTRS)

    Garcia-Munoz, M.; Mason, G. M.; Simpson, J. A.

    1978-01-01

    The isotopic composition of galactic-cosmic-ray Li, Be, and B has been measured near 100 MeV/nucleon by using the University of Chicago IMP 7 and IMP 8 cosmic-ray telescopes during 1973-1975. The measured abundances allow detailed checks of models of interstellar propagation and solar modulation to be made and conclusions to be drawn concerning the spectral forms at the source and the minimum solar modulation level. For example, comparing these results with local interstellar spectra calculated by using a 'leaky box' model, it is found that if solar modulation is ignored, there is no unique leakage mean free path consistent with all the observations. However, by taking account of a sizable level of residual solar modulation, excellent agreement is obtained between the calculated and measured abundances. Thus, these isotopic abundances confirm the old hypothesis that cosmic-ray Li, Be, and B are produced as secondaries in interstellar space.

  15. MEASUREMENTS OF COSMIC-RAY HYDROGEN AND HELIUM ISOTOPES WITH THE PAMELA EXPERIMENT

    SciTech Connect

    Adriani, O.; Bongi, M.; Barbarino, G. C.; Bazilevskaya, G. A.; Bellotti, R.; Bruno, A.; Boezio, M.; Bonvicini, V.; Formato, V.; Bogomolov, E. A.; Bottai, S.; Cafagna, F.; Campana, D.; Carlson, P.; Casolino, M.; Santis, C. De; Castellini, G.; Donato, C. De; Simone, N. De; Felice, V. Di; and others

    2016-02-10

    The cosmic-ray hydrogen and helium ({sup 1}H, {sup 2}H, {sup 3}He, {sup 4}He) isotopic composition has been measured with the satellite-borne experiment PAMELA, which was launched into low-Earth orbit on board the Resurs-DK1 satellite on 2006 June 15. The rare isotopes {sup 2}H and {sup 3}He in cosmic rays are believed to originate mainly from the interaction of high-energy protons and helium with the galactic interstellar medium. The isotopic composition was measured between 100 and 1100 MeV/n for hydrogen and between 100 and 1400 MeV/n for helium isotopes using two different detector systems over the 23rd solar minimum from 2006 July to 2007 December.

  16. Measurements of Cosmic-Ray Hydrogen and Helium Isotopes with 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.; Karelin, A. V.; Koldashov, S. V.; Koldobskiy, S.; Krutkov, S. Y.; Kvashnin, A. N.; Leonov, A.; Malakhov, V.; Marcelli, L.; Martucci, M.; Mayorov, A. G.; Menn, W.; Mergè, M.; Mikhailov, V. V.; Mocchiutti, E.; Monaco, A.; Mori, N.; Munini, R.; Osteria, G.; Palma, F.; Panico, B.; Papini, P.; Pearce, M.; Picozza, P.; Ricci, M.; Ricciarini, S. B.; Sarkar, R.; Scotti, V.; Simon, M.; Sparvoli, R.; Spillantini, P.; Stozhkov, Y. I.; Vacchi, A.; Vannuccini, E.; Vasilyev, G.; Voronov, S. A.; Yurkin, Y. T.; Zampa, G.; Zampa, N.

    2016-02-01

    The cosmic-ray hydrogen and helium (1H, 2H, 3He, 4He) isotopic composition has been measured with the satellite-borne experiment PAMELA, which was launched into low-Earth orbit on board the Resurs-DK1 satellite on 2006 June 15. The rare isotopes 2H and 3He in cosmic rays are believed to originate mainly from the interaction of high-energy protons and helium with the galactic interstellar medium. The isotopic composition was measured between 100 and 1100 MeV/n for hydrogen and between 100 and 1400 MeV/n for helium isotopes using two different detector systems over the 23rd solar minimum from 2006 July to 2007 December.

  17. An investigation of techniques for the measurement and interpretation of cosmic ray isotopic abundances. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Wiedenbeck, M. E.

    1977-01-01

    An instrument, the Caltech High Energy Isotope Spectrometer Telescope was developed to measure isotopic abundances of cosmic ray nuclei by employing an energy loss - residual energy technique. A detailed analysis was made of the mass resolution capabilities of this instrument. A formalism, based on the leaky box model of cosmic ray propagation, was developed for obtaining isotopic abundance ratios at the cosmic ray sources from abundances measured in local interstellar space for elements having three or more stable isotopes, one of which is believed to be absent at the cosmic ray sources. It was shown that the dominant sources of uncertainty in the derived source ratios are uncorrelated errors in the fragmentation cross sections and statistical uncertainties in measuring local interstellar abundances. These results were applied to estimate the extent to which uncertainties must be reduced in order to distinguish between cosmic ray production in a solar-like environment and in various environments with greater neutron enrichments.

  18. Constraints on Galactic Cosmic-Ray Origins from Elemental and Isotopic Composition Measurements

    NASA Technical Reports Server (NTRS)

    Binns, W. R.; Christian, E. R.; Cummings, A. C.; deNolfo, G. A.; Israel, M. H.; Leske, R. A.; Mewaldt, R. A,; Stone, E. C.; vonRosevinge, T. T.; Wiedenbeck, M. E.

    2013-01-01

    The most recent measurements by the Cosmic Ray Isotope Spectrometer (CRIS) aboard the Advanced Composition Explorer (ACE) satellite of ultra-heavy cosmic ray isotopic and elemental abundances will be presented. A range of isotope and element ratios, most importantly Ne-22/Ne-20, Fe-58/Fe-56, and Ga-31/Ge -32 show that the composition is consistent with source material that is a mix of approx 80% ISM (with Solar System abundances) and 20% outflow/ejecta from massive stars. In addition, our data show that the ordering of refractory and volatile elements with atomic mass is greatly improved when compared to an approx 80%/20% mix rather than pure ISM, that the refractory and volatile elements have similar slopes, and that refractory elements are preferentially accelerated by a factor of approx 4. We conclude that these data are consistent with an OB association origin of GCRs.

  19. Observation of the 60Fe Nucleosynthesis-Clock Isotope in Galactic Cosmic Rays

    NASA Technical Reports Server (NTRS)

    Binns, W. R.; Israel, M. H.; Christian, E. R.; Cummings, A. C.; de Nolfo, G. A.; Lave, K. A.; Leske, R. A.; Mewaldt, R. A.; Stone, E. C.; von Rosenvinge, T. T.

    2016-01-01

    Iron-60 (60Fe) is a radioactive isotope in cosmic rays that serves as a clock to infer an upper limit on the time between nucleosynthesis and acceleration. We have used the ACE-CRIS instrument to collect 3.55 105 iron nuclei, with energies 195 to 500 megaelectron volts per nucleon, of which we identify 15 60Fe nuclei. The 60Fe56Fe source ratio is (7.5 2.9) 105. The detection of supernova-produced 60Fe in cosmic rays implies that the time required for acceleration and transport to Earth does not greatly exceed the 60Fe half-life of 2.6 million years and that the 60Fe source distance does not greatly exceed the distance cosmic rays can diffuse over this time, 1 kiloparsec. A natural place for 60Fe origin is in nearby clusters of massive stars.

  20. Observation of the 60Fe nucleosynthesis-clock isotope in galactic cosmic rays

    NASA Astrophysics Data System (ADS)

    Binns, W. R.; Israel, M. H.; Christian, E. R.; Cummings, A. C.; de Nolfo, G. A.; Lave, K. A.; Leske, R. A.; Mewaldt, R. A.; Stone, E. C.; von Rosenvinge, T. T.; Wiedenbeck, M. E.

    2016-05-01

    Iron-60 (60Fe) is a radioactive isotope in cosmic rays that serves as a clock to infer an upper limit on the time between nucleosynthesis and acceleration. We have used the ACE-CRIS instrument to collect 3.55 × 105 iron nuclei, with energies ~195 to ~500 mega-electron volts per nucleon, of which we identify 15 60Fe nuclei. The 60Fe/56Fe source ratio is (7.5 ± 2.9) × 10-5. The detection of supernova-produced 60Fe in cosmic rays implies that the time required for acceleration and transport to Earth does not greatly exceed the 60Fe half-life of 2.6 million years and that the 60Fe source distance does not greatly exceed the distance cosmic rays can diffuse over this time, ⪍1 kiloparsec. A natural place for 60Fe origin is in nearby clusters of massive stars.

  1. Observation of the 60Fe Nucleosynthesis-Clock Isotope in Galactic Cosmic Rays

    NASA Technical Reports Server (NTRS)

    Binns, W. R.; Israel, M. H.; Christian, E. R.; Cummings, A. C.; de Nolfo, G. A.; Lave, K. A.; Leske, R. A.; Mewaldt, R. A.; Stone, E. C.; von Rosenvinge, T. T.

    2016-01-01

    Iron-60 (60Fe) is a radioactive isotope in cosmic rays that serves as a clock to infer an upper limit on the time between nucleosynthesis and acceleration. We have used the ACE-CRIS instrument to collect 3.55 105 iron nuclei, with energies 195 to 500 megaelectron volts per nucleon, of which we identify 15 60Fe nuclei. The 60Fe56Fe source ratio is (7.5 2.9) 105. The detection of supernova-produced 60Fe in cosmic rays implies that the time required for acceleration and transport to Earth does not greatly exceed the 60Fe half-life of 2.6 million years and that the 60Fe source distance does not greatly exceed the distance cosmic rays can diffuse over this time, 1 kiloparsec. A natural place for 60Fe origin is in nearby clusters of massive stars.

  2. Measurements of hydrogen and helium isotopes in Galactic cosmic rays from 1978 through 1984

    NASA Technical Reports Server (NTRS)

    Kroeger, R.

    1986-01-01

    The propagation of light cosmic rays is examined using measurements of the relative abundances of the isotopes H-1, H-2 and He-3 and He-4 made with the ISEE 3 instrumentation. It is believed that cosmic ray particles experience spallation in traveling through the interstellar medium, thereby producing the isotopes examined in the present study. The isotopic ratios are therefore expected to yield data on outward migrating particles, which lose energy while moving toward extragalactic space, i.e., the 'leaky box approximation'. The energy ranges covered are 26-138 MeV/nucleon for H-1 and He-4, 24-89 MeV/nucleon for H-2 and 43-146 MeV/nucleon for He-3. Solar activity ranged from minimum to maximum over the observational period. Details of the experimental strategies, instrumentation features and calibration techniques employed with the particle detectors are provided. Histograms were geneated of the energies attributable to each particle track and mass ratios of the various isotopes were calculated over the measured energy ranges. Account was taken of errors introduced by solar modulation, and an escape path length of 5.6-7.8 g/sq cm was estimated for particle propagation through the Galaxy. The projected path length agrees with previous estimates based on data from heavier cosmic ray nuclei.

  3. Observations of the Li, Be, and B isotopes and Constraints on Cosmic-ray Propagation

    SciTech Connect

    de Nolfo, Georgia A.; Moskalenko, I.V.; Binns, W.R.; Christian, E.R.; Cummings, A.C.; Davis, A.J.; George, J.S.; Hink, P.L.; Israel, M.H.; Leske, R.A.; Lijowski, M.; Mewaldt, R.A.; Stone, E.C.; Strong, A.W.; von Rosenvinge, T.T.; Wiedenbeck, M.E.; Yanasak, N.E.; /NASA, Goddard /Stanford U., HEPL /Washington U., St. Louis /NASA, Headquarters /Caltech, SRL /Aerospace Corp. /Garching, Max Planck Inst., MPE /Caltech, JPL

    2006-11-15

    The abundance of Li, Be, and B isotopes in galactic cosmic rays (GCR) between E=50-200 MeV/nucleon has been observed by the Cosmic Ray Isotope Spectrometer (CRIS) on NASA's ACE mission since 1997 with high statistical accuracy. Precise observations of Li, Be, B can be used to constrain GCR propagation models. We find that a diffusive reacceleration model with parameters that best match CRIS results (e.g. B/C, Li/C, etc) are also consistent with other GCR observations. A {approx}15-20% overproduction of Li and Be in the model predictions is attributed to uncertainties in the production cross-section data. The latter becomes a significant limitation to the study of rare GCR species that are generated predominantly via spallation.

  4. Observations of the Li, Be, and B Isotopes and Constraints on Cosmic-ray Propagation

    NASA Technical Reports Server (NTRS)

    deNolfo, G. A.; Moskalenko, I. V.; Binns, W. R.; Christian, E. R.; Cummings, A. C.; Davis, A. J.; George, J. S.; Hink, P. L.; Israel, M. H.; Leske, R. A.; hide

    2007-01-01

    The abundance of Li, Be, and B isotopes in galactic cosmic rays (GCR) between E=50-200 MeV/nucleon has been observed by the Cosmic Ray Isotope Spectrometer (CRIS) on NASA's ACE mission since 1997 with high statistical accuracy. Precise observations of Li, Be, B can be used to constrain GCR propagation models. We find that a diffusive reacceleration model with parameters that best match CRIS results (e.g. B/C, Li/C, etc) are also consistent with other GCR observations. A approx. 15-20% overproduction of Li and Be in the model predictions is attributed to uncertainties in the production cross-section data. The latter becomes a significant limitation to the study of rare GCR species that are generated predominantly via spallation.

  5. The charge and isotopic composition of Z equals 7-16 cosmic ray nuclei at their source

    NASA Technical Reports Server (NTRS)

    Webber, W. R.

    1981-01-01

    Using the combined data from our 1976 and 1977 balloon flights, the charge and isotopic composition of Z equals 7-16 cosmic ray nuclei have been determined. A low abundance of both N and Ne in the cosmic ray source relative to solar cosmic rays is observed. However, the cosmic ray source ratio, Ne-22/Ne is 2.75 plus or minus 0.42 times the solar ratio. A possible enhancement of the Mg-26/Mg ratio, which is 1.29 plus or minus 0.14 times the solar ratio is also observed.

  6. Cosmic-ray astrochemistry.

    PubMed

    Indriolo, Nick; McCall, Benjamin J

    2013-10-07

    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.

  7. A measurement of the isotopic composition of galactic cosmic ray carbon, nitrogen and oxygen

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

    The paper reports the results of an investigation of the isotopic composition of galactic cosmic ray carbon, nitrogen and oxygen (80-230 MeV/amu) made using the U.C. Berkeley HKH instrument aboard the ISEE-3 spacecraft. The combination of high mass resolution and a large statistical sample makes possible a precise determination of the relative isotopic abundances for these elements. In local interplanetary space the following values are found: C-13/C = 0.067 + or - 0.008, N-15/N = 0.54 + or - 0.03, O-17/O less than 0.027, and O-18/O - 0.019 + or - 0.003.

  8. MAST - A mass spectrometer telescope for studies of the isotopic composition of solar, anomalous, and galactic cosmic ray nuclei

    NASA Technical Reports Server (NTRS)

    Cook, Walter R.; Cummings, Alan C.; Cummings, Jay R.; Garrard, Thomas L.; Kecman, Branislav; Mewaldt, Richard A.; Selesnick, Richard S.; Stone, Edward C.; Von Rosenvinge, T. T.

    1993-01-01

    The Mass Spectrometer Telescope (MAST) on SAMPEX is designed to provide high resolution measurements of the isotopic composition of energetic nuclei from He to Ni (Z = 2 to 28) over the energy range from about 10 to several hundred MeV/nuc. During large solar flares MAST will measure the isotopic abundances of solar energetic particles to determine directly the composition of the solar corona, while during solar quiet times MAST will study the isotopic composition of galactic cosmic rays. In addition, MAST will measure the isotopic composition of both interplanetary and trapped fluxes of anomalous cosmic rays, believed to be a sample of the nearby interstellar medium.

  9. Observations of hydrogen and helium isotopes in solar cosmic rays. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Hurford, G. J.

    1974-01-01

    The isotopic composition of hydrogen and helium in solar cosmic rays provides a means of studying solar flare particle acceleration mechanisms since the enhanced relative abundance of rare isotopes, such as H-2, H-3, and He-3, is due to their production by inelastic nuclear collisions in the solar atmosphere during the flare. Electron isotope spectrometer on an IMP spacecraft was used to measure this isotopic composition. The response of the dE/dx-E particle telescope is discussed, and alpha particle channeling in thin detectors is identified as an important background source affecting measurement of low values of (He-3/He-4). The flare-averaged results obtained for the period October, 1972 November, 1973 are given.

  10. Observation of the 60Fe Nucleosynthesis-Clock Isotope in Galactic Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Binns, W. R.; Israel, M. H.; Christian, E. R.; Cummings, A. C.; de Nolfo, G. A.; Lave, K. A.; Leske, R. A.; Mewaldt, R. A.; Stone, E. C.; von Rosenvinge, T. T.; Wiedenbeck, M. E.

    2017-01-01

    We have measured the abundance of 60Fe, a radioactive isotope in cosmic rays that serves as a clock to infer an upper limit on the time between nucleosynthesis in supernovae and cosmic ray acceleration. The ACE-CRIS instrument has collected 3.55 ×105 iron nuclei from which we have resolved 15 60Fe nuclei. From this a 60Fe/56Fe source ratio of (7.5 +/-2.9) ×10-5 is obtained. The detection of supernova-produced 60Fe in cosmic rays implies that the time required for acceleration and transport to Earth does not greatly exceed the 60Fe half-life of 2.6 Myr and that the 60Fe source distance does not greatly exceed the distance cosmic rays can diffuse over this time, < 1 kpc. A natural place for 60Fe origin is in nearby clusters of massive stars. This research is supported by NASA under Grant # NNX13AH66G.

  11. Isotope selective photodissociation of N2 by the interstellar radiation field and cosmic rays

    NASA Astrophysics Data System (ADS)

    Heays, Alan N.; Visser, Ruud; Gredel, Roland; Ubachs, Wim; Lewis, Brenton R.; Gibson, Stephen T.; van Dishoeck, Ewine F.

    2014-02-01

    Context. Photodissociation of 14N2 and 14N 15N occurs in interstellar clouds, circumstellar envelopes, protoplanetary discs, and other environments due to ultraviolet radiation originating from stellar sources and the presence of cosmic rays. This source of N atoms initiates the formation of more complex N-bearing species and may influence their isotopic composition. Aims: We study the photodissociation rates of 14N 15N by ultraviolet continuum radiation and both isotopologues in a field of cosmic ray induced photons. To determine the effect of these on the isotopic composition of more complex molecules. Methods: High-resolution theoretical photodissociation cross sections of N2 are used from an accurate and comprehensive quantum-mechanical model of the molecule based on laboratory experiments. A similarly high-resolution spectrum of H2 emission following interactions with cosmic rays has been constructed. The spectroscopic data are used to calculate photodissociation rates which are then input into isotopically differentiated chemical models, describing an interstellar cloud and a protoplanetary disc. Results: The photodissociation rate of 14N 15N in a Draine field assuming 30 K excitation is 1.73 × 10-10 s-1, within 4% of the rate for 14N2, and the rate due to cosmic ray induced photons assuming an H2 ionisation rate of ζ = 10-16 s-1 is about 10-15 s-1, with up to a factor of 10 difference between isotopologues. Shielding functions for 14N15N by 14N2, H2, and H are presented. Incorporating these into an interstellar cloud model, an enhancement of the atomic 15N/14N ratio over the elemental value is obtained due to the self-shielding of external radiation at an extinction of about 1.5 mag. This effect is larger where assumed grain growth has reduced the opacity of dust to ultraviolet radiation. The transfer of photolytic isotopic fractionation of N and N2 to other molecules is demonstrated to be significant in a protoplanetary disc model with grain growth, and

  12. 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.

  13. The elemental and isotopic composition of quiet time low energy cosmic rays

    NASA Technical Reports Server (NTRS)

    Smith, B.; Mcdonald, F. B.

    1983-01-01

    Isotopic abundances during several periods of solar quiet times are derived from multidimensional analysis of double dE/dX modes made with two 150 micron dE detectors and a 3000 micron stopping E detector. The spectra of the low-energy cosmic rays suggest that all the primary species of elements exhibit flux enhancements. The flux increases of 5-12 MeV/N for C, Mg, Si, and Fe are different from the anomalous components and may result from solar contamination of the quiet time data or from interplanetary acceleration processes. They may be anomalous components (ACR), although to a lesser extent than He, N, O, and Ne. The isotopic data indicate that the ACR component is predominantly N-14, O-16, and Ne-20. The isotopic compositions require that the ACRs have traversed a very limited amount of material, suggesting a local origin for them.

  14. MEASUREMENT OF THE ISOTOPIC COMPOSITION OF HYDROGEN AND HELIUM NUCLEI IN COSMIC RAYS WITH THE PAMELA EXPERIMENT

    SciTech Connect

    Adriani, O.; Bongi, M.; Barbarino, G. C.; Bazilevskaya, G. A.; Bellotti, R.; Bruno, A.; Boezio, M.; Bonvicini, V.; Carbone, R.; Bogomolov, E. A.; Borisov, S.; Casolino, M.; De Pascale, M. P.; Bottai, S.; Cafagna, F.; Campana, D.; Carlson, P.; Castellini, G.; Danilchenko, I. A.; De Santis, C.; and others

    2013-06-10

    The satellite-borne experiment PAMELA has been used to make new measurements of cosmic ray H and He isotopes. The isotopic composition was measured between 100 and 600 MeV/n for hydrogen and between 100 and 900 MeV/n for helium isotopes over the 23rd solar minimum from 2006 July to 2007 December. The energy spectrum of these components carries fundamental information regarding the propagation of cosmic rays in the galaxy which are competitive with those obtained from other secondary to primary measurements such as B/C.

  15. Evolution of the Cerenkov x total-energy telescope for isotopic analysis of cosmic rays

    NASA Technical Reports Server (NTRS)

    Webber, W. R.; Simpson, G. A.; Lezniak, J. A.; Kish, J. C.

    1978-01-01

    This paper discusses the evolution of the Cerenkov x total energy technique for isotopic analysis of cosmic rays as developed by the University of New Hampshire. This technique is generally restricted to particles with Z greater than 6, and the best mass resolution is achieved over a relatively narrow energy range just above the Cerenkov threshold. State-of-the-art mass resolution is now 0.3-0.4 AMU throughout the charge range z = 8-28 and over an energy range varying from about 40 MeV/n at lower Z to about 200 MeV/n for Fe.

  16. Cosmic Rays below 1 GeV/nucleon: Results from 19 Years of Observations with the Cosmic Ray Isotope Spectrometer on ACE

    NASA Astrophysics Data System (ADS)

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

    2017-01-01

    The Cosmic Ray Isotope Spectrometer (CRIS) instrument on NASA's Advanced Composition Explorer mission has been making high-precision measurements of cosmic-ray elemental and isotopic composition and energy spectra below 1 GeV/nucleon since August 1997. The long period of data collection, now in its 20th year, and the large geometrical acceptance ( 250 cm2sr) have made it possible to study very rare species, including including some primary radionuclides and a number of stable elements with Z >28. Using measurements of elemental spectra on time scales as short as a month, CRIS has been tracking the level of solar modulation over nearly two full solar cycles, including the lowest level encountered since the start of the space age. The energy range covered by these spectra is being extended using new techniques for measuring nuclides that penetrate beyond the sensitive volume of the CRIS instrument and by utilizing complementary data obtained from the Solar Isotope Spectrometer (SIS), also on ACE. A summary of the most significant cosmic-ray results from ACE will be presented and future prospects will be discussed.

  17. Observation of the ⁶⁰Fe nucleosynthesis-clock isotope in galactic cosmic rays.

    PubMed

    Binns, W R; Israel, M H; Christian, E R; Cummings, A C; de Nolfo, G A; Lave, K A; Leske, R A; Mewaldt, R A; Stone, E C; von Rosenvinge, T T; Wiedenbeck, M E

    2016-05-06

    Iron-60 ((60)Fe) is a radioactive isotope in cosmic rays that serves as a clock to infer an upper limit on the time between nucleosynthesis and acceleration. We have used the ACE-CRIS instrument to collect 3.55 × 10(5) iron nuclei, with energies ~195 to ~500 mega-electron volts per nucleon, of which we identify 15 (60)Fe nuclei. The (60)Fe/(56)Fe source ratio is (7.5 ± 2.9) × 10(-5) The detection of supernova-produced (60)Fe in cosmic rays implies that the time required for acceleration and transport to Earth does not greatly exceed the (60)Fe half-life of 2.6 million years and that the (60)Fe source distance does not greatly exceed the distance cosmic rays can diffuse over this time, ⪍1 kiloparsec. A natural place for (60)Fe origin is in nearby clusters of massive stars. Copyright © 2016, American Association for the Advancement of Science.

  18. Nitrogen isotopes in lunar soils as a measure of cosmic-ray exposure and regolith history

    NASA Technical Reports Server (NTRS)

    Becker, R. H.; Clayton, R. N.

    1977-01-01

    Previous studies have shown that the bulk of the nitrogen in soils has been implanted by the solar wind, that the N-15/N-14 ratio of the implanted nitrogen has apparently increased with time, and that both soils and rocks contain a nitrogen component greatly enriched in N-15, relative to natural abundance ratios, due to cosmic-ray spallation. An investigation was, therefore, conducted to test the feasibility of using spallation-produced N-15 for determining cosmic-ray exposure ages. Samples from several depths in the Apollo 15 deep drill core were analyzed. The data obtained have also been evaluated with regard to possible models for the prior history of the material now in the Apollo 15 core. In addition, analyses have been performed of several other soil samples considered for various reasons to be of particular interest, such as orange soil 74220 and its companion 74240, Apollo 16 drill core sample 60002, and the apparently peculiar fillet soil 67461. Wherever possible, analyses were carried out by step-wise heating rather than by total pyrolysis. On the basis of the results of the investigation it is concluded that nitrogen isotope ratio determinations provide a usable method for determining cosmic-ray exposures for soils.

  19. Nitrogen isotopes in lunar soils as a measure of cosmic-ray exposure and regolith history

    NASA Technical Reports Server (NTRS)

    Becker, R. H.; Clayton, R. N.

    1977-01-01

    Previous studies have shown that the bulk of the nitrogen in soils has been implanted by the solar wind, that the N-15/N-14 ratio of the implanted nitrogen has apparently increased with time, and that both soils and rocks contain a nitrogen component greatly enriched in N-15, relative to natural abundance ratios, due to cosmic-ray spallation. An investigation was, therefore, conducted to test the feasibility of using spallation-produced N-15 for determining cosmic-ray exposure ages. Samples from several depths in the Apollo 15 deep drill core were analyzed. The data obtained have also been evaluated with regard to possible models for the prior history of the material now in the Apollo 15 core. In addition, analyses have been performed of several other soil samples considered for various reasons to be of particular interest, such as orange soil 74220 and its companion 74240, Apollo 16 drill core sample 60002, and the apparently peculiar fillet soil 67461. Wherever possible, analyses were carried out by step-wise heating rather than by total pyrolysis. On the basis of the results of the investigation it is concluded that nitrogen isotope ratio determinations provide a usable method for determining cosmic-ray exposures for soils.

  20. Isotopic composition of cosmic ray nitrogen at 1.5 GeV/amu

    NASA Technical Reports Server (NTRS)

    Dwyer, R.; Meyer, P.

    1975-01-01

    For any location, the earth's magnetic field acts as a filter for incoming cosmic rays, allowing only particles above a certain rigidity. The relative isotopic composition of abundant elements can be measured with a detector sensitive to the velocity of particles in the penumbra of the earth's magnetic field. In this paper, the nitrogen velocity spectrum is compared with that of carbon plus oxygen as a reference, since in this case Z-dependent effects are minimal. The form of the energy spectrum of carbon, nitrogen, and oxygen, needed for proper correction, was measured in the same experiment. The results were obtained using a scintillator-Cerenkov counter telescope with a geometric factor of 0.25 sq in sr, flown twice on high-altitude balloons from Palestine, Texas, obtaining an exposure factor of 20 sq m sr hr. Results are presented on the isotopic composition of nitrogen at about 1.5GeV/amu.

  1. A Search for Heavy Hydrogen Isotopes in Cosmic-Ray Atmospheric Albedo With SAMPEX/PET

    NASA Astrophysics Data System (ADS)

    Looper, M. D.; Blake, J. B.; Mewaldt, R. A.

    2008-12-01

    Bidoli et al. (2003) reported observations of large abundances of deuterium and tritium relative to hydrogen below a few tens of MeV/nuc among the secondary particles escaping the atmosphere after the impact of primary cosmic rays. The SAMPEX satellite spent much of 1996-1998 spinning at 1 RPM, and since late 2007 it has been back in 1 RPM spin mode again; thus its sensors spend half their time looking downward, allowing atmospheric albedo particles to be observed directly. With the Proton/Electron Telescope (PET), hydrogen isotopes are measured in the energy range from about 18 MeV/nuc to 60 to 500 MeV/nuc depending on species. We have previously used PET to measure deuterium and tritium among the Earth's geomagnetically-trapped particle population; we will report here on the results of a search for these isotopes among atmospheric albedo during solar-activity minimum conditions.

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

    NASA Astrophysics Data System (ADS)

    Formato, V.; 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.; Carbone, R.; Carlson, P.; Casolino, M.; Castellini, G.; De Donato, C.; De Pascale, M. P.; De Santis, C.; De Simone, N.; Di Felice, V.; Galper, A. M.; Karelin, A. V.; Koldashov, S. V.; Koldobskiy, S.; Krutkov, Y.; Kvashnin, A. N.; Leonov, A.; Malakhov, V.; Marcelli, L.; Martucci, M.; Mayorov, A. G.; Menn, W.; Mergè, M.; Mikhailov, V. V.; Mocchiutti, E.; Monaco, A.; Mori, N.; Munini, R.; Osteria, G.; Palma, F.; Papini, P.; Pearce, M.; Picozza, P.; Pizzolotto, C.; Ricci, M.; Ricciarini, S. B.; Sarkar, R.; Simon, M.; Scotti, V.; Sparvoli, R.; Spillantini, P.; Stozhkov, Y. I.; Vacchi, A.; Vannuccini, E.; Vasilyev, G.; Voronov, S. A.; Yurkin, Y. T.; Zampa, G.; Zampa, N.; Zverev, V. G.

    2014-04-01

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

  3. Physics of the Isotopic Dependence of Galactic Cosmic Ray Fluence Behind Shielding

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Saganti, Premkumar B.; Hu, Xiao-Dong; Kim, Myung-Hee Y.; Cleghorn, Timothy F.; Wilson, John W.; Tripathi, Ram K.; Zeitlin, Cary J.

    2003-01-01

    For over 25 years, NASA has supported the development of space radiation transport models for shielding applications. The NASA space radiation transport model now predicts dose and dose equivalent in Earth and Mars orbit to an accuracy of plus or minus 20%. However, because larger errors may occur in particle fluence predictions, there is interest in further assessments and improvements in NASA's space radiation transport model. In this paper, we consider the effects of the isotopic composition of the primary galactic cosmic rays (GCR) and the isotopic dependence of nuclear fragmentation cross-sections on the solution to transport models used for shielding studies. Satellite measurements are used to describe the isotopic composition of the GCR. Using NASA's quantum multiple-scattering theory of nuclear fragmentation (QMSFRG) and high-charge and energy (HZETRN) transport code, we study the effect of the isotopic dependence of the primary GCR composition and secondary nuclei on shielding calculations. The QMSFRG is shown to accurately describe the iso-spin dependence of nuclear fragmentation. The principal finding of this study is that large errors (plus or minus 100%) will occur in the mass-fluence spectra when comparing transport models that use a complete isotope grid (approximately 170 ions) to ones that use a reduced isotope grid, for example the 59 ion-grid used in the HZETRN code in the past, however less significant errors (less than 20%) occur in the elemental-fluence spectra. Because a complete isotope grid is readily handled on small computer workstations and is needed for several applications studying GCR propagation and scattering, it is recommended that they be used for future GCR studies.

  4. Alteration of the Carbon and Nitrogen Isotopic Composition in the Martian Surface Rocks Due to Cosmic Ray Exposure

    NASA Technical Reports Server (NTRS)

    Pavlov, A. A.; Pavlov, A. K.; Ostryakov, V. M.; Vasilyev, G. I.; Mahaffy, P.; Steele, A.

    2014-01-01

    C-13/C-12 and N-15/N-14 isotopic ratios are pivotal for our understanding of the Martian carbon cycle, history of the Martian atmospheric escape, and origin of the organic compounds on Mars. Here we demonstrate that the carbon and nitrogen isotopic composition of the surface rocks on Mars can be significantly altered by the continuous exposure of Martian surface to cosmic rays. Cosmic rays can effectively produce C-13 and N-15 isotopes via spallation nuclear reactions on oxygen atoms in various Martian rocks. We calculate that in the top meter of the Martian rocks, the rates of production of both C-13 and N-15 due to galactic cosmic rays (GCRs) exposure can vary within 1.5-6 atoms/cm3/s depending on rocks' depth and chemical composition. We also find that the average solar cosmic rays can produce carbon and nitrogen isotopes at a rate comparable to GCRs in the top 5-10 cm of the Martian rocks. We demonstrate that if the total carbon content in a surface Martian rock is <10 ppm, then the "light," potentially "biological" C-13/C-12 ratio would be effectively erased by cosmic rays over 3.5 billion years of exposure. We found that for the rocks with relatively short exposure ages (e.g., 100 million years), cosmogenic changes in N-15/N-14 ratio are still very significant. We also show that a short exposure to cosmic rays of Allan Hills 84001 while on Mars can explain its high-temperature heavy nitrogen isotopic composition (N-15/N-14). Applications to Martian meteorites and the current Mars Science Laboratory mission are discussed.

  5. Alteration of the carbon and nitrogen isotopic composition in the Martian surface rocks due to cosmic ray exposure

    NASA Astrophysics Data System (ADS)

    Pavlov, A. A.; Pavlov, A. K.; Ostryakov, V. M.; Vasilyev, G. I.; Mahaffy, P.; Steele, A.

    2014-06-01

    13C/12C and 15N/14N isotopic ratios are pivotal for our understanding of the Martian carbon cycle, history of the Martian atmospheric escape, and origin of the organic compounds on Mars. Here we demonstrate that the carbon and nitrogen isotopic composition of the surface rocks on Mars can be significantly altered by the continuous exposure of Martian surface to cosmic rays. Cosmic rays can effectively produce 13C and 15N isotopes via spallation nuclear reactions on oxygen atoms in various Martian rocks. We calculate that in the top meter of the Martian rocks, the rates of production of both 13C and 15N due to galactic cosmic rays (GCRs) exposure can vary within 1.5-6 atoms/cm3/s depending on rocks' depth and chemical composition. We also find that the average solar cosmic rays can produce carbon and nitrogen isotopes at a rate comparable to GCRs in the top 5-10 cm of the Martian rocks. We demonstrate that if the total carbon content in a surface Martian rock is <10 ppm, then the "light," potentially "biological" 13C/12C ratio would be effectively erased by cosmic rays over 3.5 billion years of exposure. We found that for the rocks with relatively short exposure ages (e.g., 100 million years), cosmogenic changes in 15N/14N ratio are still very significant. We also show that a short exposure to cosmic rays of Allan Hills 84001 while on Mars can explain its high-temperature heavy nitrogen isotopic composition (15N/14N). Applications to Martian meteorites and the current Mars Science Laboratory mission are discussed.

  6. Alteration of the Carbon and Nitrogen Isotopic Composition in the Martian Surface Rocks Due to Cosmic Ray Exposure

    NASA Technical Reports Server (NTRS)

    Pavlov, A. A.; Pavlov, A. K.; Ostryakov, V. M.; Vasilyev, G. I.; Mahaffy, P.; Steele, A.

    2014-01-01

    C-13/C-12 and N-15/N-14 isotopic ratios are pivotal for our understanding of the Martian carbon cycle, history of the Martian atmospheric escape, and origin of the organic compounds on Mars. Here we demonstrate that the carbon and nitrogen isotopic composition of the surface rocks on Mars can be significantly altered by the continuous exposure of Martian surface to cosmic rays. Cosmic rays can effectively produce C-13 and N-15 isotopes via spallation nuclear reactions on oxygen atoms in various Martian rocks. We calculate that in the top meter of the Martian rocks, the rates of production of both C-13 and N-15 due to galactic cosmic rays (GCRs) exposure can vary within 1.5-6 atoms/cm3/s depending on rocks' depth and chemical composition. We also find that the average solar cosmic rays can produce carbon and nitrogen isotopes at a rate comparable to GCRs in the top 5-10 cm of the Martian rocks. We demonstrate that if the total carbon content in a surface Martian rock is <10 ppm, then the "light," potentially "biological" C-13/C-12 ratio would be effectively erased by cosmic rays over 3.5 billion years of exposure. We found that for the rocks with relatively short exposure ages (e.g., 100 million years), cosmogenic changes in N-15/N-14 ratio are still very significant. We also show that a short exposure to cosmic rays of Allan Hills 84001 while on Mars can explain its high-temperature heavy nitrogen isotopic composition (N-15/N-14). Applications to Martian meteorites and the current Mars Science Laboratory mission are discussed.

  7. A balloon measurement of the isotopic composition of galactic cosmic ray iron

    SciTech Connect

    Grove, J.E.

    1989-01-01

    The isotopic composition of galactic cosmic ray iron in the energy interval of approximately 1550 to 2200 MeV/nucleon was measured using a balloon-borne mass spectrometer. The instrument was flown from Palestine, Texas, in May 1984 for greater than 35 hours at an atmospheric depth of approximately 6 g/sq cm. Masses were derived by the Cerenkov-Energy technique. The Cerenkov counter employed a silica aerogel radiator with an index of refraction n = 1.1. Particle energies were measured in a stack of NaI(Tl) scintillators, which also provided particle trajectories. A detailed discussion of the sources of mass uncertainty is presented, including an analytic model of the contribution from fluctuations in the Cerenkov yield from knock-on electrons. The achieved mass resolution is approximately 0.65 amu, which is consistent with the theoretical estimate. An Fe-54/Fe-56 abundance ratio of 0.14(sup +0.18)(sub -0.11) and an 84 percent confidence upper limit of Fe-58/Fe-56 is less than or = to 0.07 at the top of the atmosphere is reported. Combining the data with those of precious measurements of the composition of iron at lower energies, and using a model of the galactic propagation, cosmic-ray source abundance ratios of Fe-54/Fe-56 = 0.064(sup +0.032)(sub -0.027) and Fe-58/F3-56 is less than or = to 0.062 were derived. These values are consistent with the composition of solar system iron and place restrictions on the conditions under which cosmic-ray iron is synthesized.

  8. Study of cosmic-ray H and He isotopes at 23 AU

    NASA Technical Reports Server (NTRS)

    Seo, E. S.; Mcdonald, F. B.; Lal, N.; Webber, W. R.

    1994-01-01

    We have measured the spectra of H and He isotopes during the 1987 solar minimum with the cosmic-ray detector system (CRS) on the Voyager 2 spacecraft. By carrying out the measurement near solar minimum and at large heliospheric distances, the effects of solar modulations were reduced. In particular, the adiabatic energy losses were smaller, and these results from 23 AU over the solar minimum period of cycle 21 represent observations at energies not accessible from previous measurements near 1 AU. The modulated spectra with the diffusion coefficient constant k(sub 0) = 3.15 x 10(exp 22) sq cm/s (which corresponds to a solar modulation parameter of 360 MV at 23 AU and 500 MV at 1 AU) agree well with both our data at 23 AU and the previous solar minimum measurements at 1 AU. The measured H-1 and H-2 spectra are both consistent with the calculated spectra, using standard Galactic and heliospheric propagation models without invoking an anomalous hydrogen component. With the fixed modulation parameter of 360 MV, the mean pathlengths, source spectra, and cross sections were varied to study the effects of different input parameters on the spectra and relative abundances. At this stage of our work, we have not found any strong evidence from the low-energy H-2 and He-3 data that H-1 and He-4 should have a different propagation history, or different types of source spectra from the heavier cosmic-ray nuclei.

  9. Time Variations of Cosmic-Ray Helium Isotopes with BESS-Polar I

    NASA Technical Reports Server (NTRS)

    Abe, K.; Fuke, H.; Haino, S.; Hams, T.; Hasegawa, M.; Horikoshi, A.; Itazaki, A.; Kim, K. C.; Kumazawa, T.; Kusumoto, A.; hide

    2013-01-01

    The Balloon-borne Experiment with a Superconducting Spectrometer (BESS) is configured with a solenoidal superconducting magnet and a suite of precision particle detectors, including time-of-flight hodoscopes based on plastic scintillators, a silica-aerogel Cherenkov detector, and a high resolution tracking system with a central jet-type drift chamber. The charges of incident particles are determined from energy losses in the scintillators. Their magnetic rigidities (momentum/charge) are measured by reconstructing each particle trajectory in the magnetic field, and their velocities are obtained by using the time-of-flight system. Together, these measurements can accurately identify helium isotopes among the incoming cosmic-ray helium nuclei up to energies in the GeV per nucleon region. The BESS-Polar I instrument flew for 8.5 days over Antarctica from December 13th to December 21st, 2004. Its long-duration flight and large geometric acceptance allow the time variations of isotopic fluxes to be studied for the first time. The time variations of helium isotope fluxes are presented here for rigidities from 1.2 to 2.5 GV and results are compared to previously reported proton data and neutron monitor data.

  10. Time Variations of Cosmic-Ray Helium Isotopes with Bess-Polar I

    NASA Technical Reports Server (NTRS)

    Abe, K.; Fuke, H.; Haino, S.; Hams, T.; Hasegawa, M.; Horikoshi, A.; Itazaki, A.; Kim, K. C.; Kumazawa, T.; Kusumoto, A.; hide

    2013-01-01

    The Balloon-borne Experiment with a Superconducting Spectrometer (BESS) is configured with a solenoidal superconducting magnet and a suite of precision particle detectors, including time-of-flight hodoscopes based on plastic scintillators, a silica-aerogel Cherenkov detector, and a high resolution tracking system with a central jet-type drift chamber. The charges of incident particles are determined from energy losses in the scintillators. Their magnetic rigidities (momentum charge) are measured by reconstructing each particle trajectory in the magnetic field, and their velocities are obtained by using the time-of-flight system. Together, these measurements can accurately identify helium isotopes among the incoming cosmic-ray helium nuclei up to energies in the GeV per nucleon region. The BESS-Polar I instrument flew for 8.5 days over Antarctica from December 13th to December 21st, 2004. Its long-duration flight and large geometric acceptance allow the time variations of isotopic fluxes to be studied for the first time. The time variations of helium isotope fluxes are presented here for rigidities from 1.2 to 2.5 GV and results are compared to previously reported proton data and neutron monitor data.

  11. Time variations of cosmic-ray helium isotopes with BESS-Polar I

    NASA Astrophysics Data System (ADS)

    Abe, K.; Fuke, H.; Haino, S.; Hams, T.; Hasegawa, M.; Horikoshi, A.; Itazaki, A.; Kim, K. C.; Kumazawa, T.; Kusumoto, A.; Lee, M. H.; Makida, Y.; Matsuda, S.; Matsukawa, Y.; Matsumoto, K.; Mitchell, J. W.; Moiseev, A. A.; Nishimura, J.; Nozaki, M.; Orito, R.; Ormes, J. F.; Picot-Clémente, N.; Sakai, K.; Sasaki, M.; Seo, E. S.; Shikaze, Y.; Shinoda, R.; Streitmatter, R. E.; Suzuki, J.; Takasugi, Y.; Takeuchi, K.; Tanaka, K.; Thakur, N.; Yamagami, T.; Yamamoto, A.; Yoshida, T.; Yoshimura, K.

    2014-05-01

    The Balloon-borne Experiment with a Superconducting Spectrometer (BESS) is configured with a solenoidal superconducting magnet and a suite of precision particle detectors, including time-of-flight hodoscopes based on plastic scintillators, a silica-aerogel Cherenkov detector, and a high resolution tracking system with a central jet-type drift chamber. The charges of incident particles are determined from energy losses in the scintillators. Their magnetic rigidities (momentum/charge) are measured by reconstructing each particle trajectory in the magnetic field, and their velocities are obtained by using the time-of-flight system. Together, these measurements can accurately identify helium isotopes among the incoming cosmic-ray helium nuclei up to energies in the GeV per nucleon region. The BESS-Polar I instrument flew for 8.5 days over Antarctica from December 13th to December 21st, 2004. Its long-duration flight and large geometric acceptance allow the time variations of isotopic fluxes to be studied for the first time. The time variations of helium isotope fluxes are presented here for rigidities from 1.2 to 2.5 GV and results are compared to previously reported proton data and neutron monitor data.

  12. A chart of cosmic ray isotopes. [showing radioactive decay, abundance and nucleosynthesis

    NASA Technical Reports Server (NTRS)

    Waddington, C. J.

    1975-01-01

    A chart has been prepared that lists some of the properties relevant to cosmic ray studies of all the significant nuclides between lithium and nickel. On this chart there are shown all the possible decays that might be of interest in the unique conditions experienced by cosmic ray nuclei, various abundance figures and the probable nucleosynthesis processes of origin.

  13. Cosmic Ray Exposure Modification of the Molybdenum Isotopic Composition of Iron Meteorites

    NASA Astrophysics Data System (ADS)

    Worsham, E. A.; Bermingham, K. R.; Walker, R. J.

    2015-12-01

    Accurate grouping of meteorites that represent specific planetary bodies is paramount to understanding early planetary processes, such as accretion and differentiation. Most iron meteorite groups represent the cores of differentiated planetesimals, and therefore hold insights into the timing and mechanisms of core formation and crystallization. Molybdenum isotopic compositions have been shown to vary between meteorite groups due to nucleosynthetic heterogeneities, and, thus, can be used as a genetic tracer [1]. Where isotopic differences can be resolved among iron meteorites purported to be from the same group, it is possible to reject genetic linkages. However, implicit in the use of Mo as a genetic tracer is the assumption of intra-group homogeneity, which does not hold true for Os isotopes, for example [2]. High neutron fluence due to cosmic ray exposure (CRE) has been shown to modify Os isotopic compositions [2]. We report deviations of 95Mo, normalized to 98Mo/96Mo to correct for instrumental mass bias, between iron meteorites of the same group. For instance, in group IVB, Tlacotepec has a 95Mo/96Mo ratio that is ~30 ppm lower than that of most other IVB iron meteorites. Molybdenum-95 is correlated with 189Os and 190Os in each of the three iron meteorite groups examined here, indicating that Mo isotopes are also modified by CRE. Because 95Mo has the largest neutron capture cross section and resonance integral of the Mo isotopes, the likely nuclear reaction is: 95Mo(n,γ)96Mo. The correlation between 95Mo and 189Os or 190Os can be used to correct the Mo isotopes to a pre-exposure composition, as has been done for W isotopes [e.g., 3]. The pre-exposure 95Mo for the IAB complex, IVB, and IIIAB iron meteorite groups is calculated as the y-intercept of each of the slopes defined by the correlation of 95Mo with 189Os. [1] Dauphas et al. (2002) Astrophys. J. 565, 640-644. [2] Walker (2012) EPSL 351-352, 36-44. [3] Wittig et al. (2013) EPSL 361, 152-161.

  14. Isotopic composition of low energy beryllium in the galactic cosmic rays

    NASA Technical Reports Server (NTRS)

    Garcia-Munoz, M.; Mason, G. M.; Simpson, J. A.

    1974-01-01

    The multielement charged-particle telescope on the IMP-5 satellite obtained data essentially continuously for more than three years in the interplanetary medium under stable instrument conditions which have made it possible to separate the H, He, and Be isotopes in the galactic cosmic radiation using the technique of double dE/dx vs residual E and particle range measurements. Special emphasis is placed on demonstrating that in the energy range from 50 to 150 MeV/nucleon the instrument clearly resolved Be-7 vs Be-9. A detailed analysis of approximately 100 Be events collected over the mission lifetime yields the ratios (Be-7/Be) = 0.50 plus or minus 0.07, (Be-9/Be) = 0.41 plus or minus 0.10, and (Be-10/Be) = 0.09 plus or minus 0.10. These results are consistent with current models of galactic cosmic ray propagation after taking account of the effects of solar modulation.

  15. A determination of the resolution capabilities of a cosmic ray isotope spectrometer

    NASA Astrophysics Data System (ADS)

    Davis, Andrew Jessop

    1993-01-01

    Despite advances made in determining the composition of galactic Cosmic Rays (CR), their origin is still uncertain, as is the exact mechanism for their acceleration to high energies. The relative abundances of CR iron-group isotopes are an important probe of the nature of the sources of CR, and thus constrain theories of the nucleosynthesis of matter occurring there. The time-delay between the nucleosynthesis of CR source material and its acceleration to high energies can also be measured using CR isotope abundances. The Scintillating Optical Fiber Isotope Experiment (SOFIE) is a Cerenkov-dE/dx-range experiment designed to study the isotopic composition of heavy CR aboard a high-altitude balloon. The first flight of SOFIE, in 1988, did not provide scientific data because of problems with newly developed detectors. This thesis describes improvements that have been made in the design of the instrument which enable it to achieve the high resolution required to resolve heavy isotopes in the CR. Also described is a new study which predicts the mass resolution of the instrument at silicon and iron, and the results of an accelerator calibration which verifies the functionality of the instrument and the mass resolution predictions. The low abundance of iron-group isotopes in the CR makes their measurement especially difficult. SOFIE uses new detectors incorporating scintillating optical fiber technology to measure charged particle trajectories, and to image their tracks in the range detector. These detectors make it possible to combine high resolution and high collecting power in the same instrument. In December, 1990, we calibrated SOFIE at the LBL Bevalac heavy ion accelerator. An analysis of the calibration data is presented, including charge resolution, resolution and efficiency of the trajectory detectors, and mass resolution at silicon and iron. We find the mass resolution to be approximately 0.25 amu at silicon and approximately 0.4 amu at iron. These results are

  16. A measurement of cosmic-ray beryllium isotopes from 200 to 1500 MeV per nucleon

    NASA Technical Reports Server (NTRS)

    Buffington, A.; Orth, C. D.; Mast, T. S.

    1978-01-01

    A balloon-borne superconducting magnetic spectrometer was used in the measurement of cosmic-ray isotopic abundances from lithium through oxygen in the energy range 200-1500 MeV per nucleon. Except for Be-7 all isotopic composition is essentially energy-independent. Be-10 is nearly absent, indicating a mean cosmic-ray age of 6(-3, +10) x 10 to the 6th years. Above about 500 MeV per nucleon, Be-7 drops dramatically in abundance relative to Be-9 and C. By 1500 MeV per nucleon, the relative abundance of Be-7 has become one-half of its lower-energy value. Since Be-7 is the only isotope measured which decays by electron capture, this result is interpreted as indicating that higher-energy Be-7 had an appreciable probability of not being stripped of all its electrons before entering interstellar space where electron pickup is negligible.

  17. Galactic cosmic ray composition

    NASA Technical Reports Server (NTRS)

    Meyer, J. P.

    1986-01-01

    An assessment is given of the galactic cosmic ray source (GCRS) elemental composition and its correlation with first ionization potential. The isotopic composition of heavy nuclei; spallation cross sections; energy spectra of primary nuclei; electrons; positrons; local galactic reference abundances; comparison of solar energetic particles and solar coronal compositions; the hydrogen; lead; nitrogen; helium; and germanium deficiency problems; and the excess of elements are among the topics covered.

  18. Energy Spectrum Measurements of Cosmic-Ray Hydrogen and Helium Isotopes with the BESS-Polar II Instrument

    NASA Astrophysics Data System (ADS)

    Picot-Clemente, Nicolas

    2014-03-01

    The Balloon-Borne Experiment with a Superconducting Spectrometer (BESS-Polar II) flew successfully over Antarctica during 24.5 days in December 2007 through January 2008 during a period of minimum solar activity. The long duration of the flight, and the good stability of the detectors, improved by a factor of 5 the number of cosmic-ray events previously recorded with BESS-Polar I, reaching about 4.7 billion collected particles. Energy spectrum of cosmic-ray hydrogen and helium isotopes have been measured with the instrument from 0.2 to about 1.5 GeV/n, with unprecedented accuracy. These new flux and ratio measurements provide important information to better understand the propagation history of cosmic rays in the Galaxy. The results obtained with the BESS-Polar II instrument will be presented and compared with different propagation models.

  19. Geochronology and monitoring of cosmic rays for accumulating cosmogenic isotopes 53Mn and 10Be in terrestrial rocks

    NASA Astrophysics Data System (ADS)

    Yants, V. E.; Lebedev, S. G.; Sobolevsky, N. M.

    2017-09-01

    The paper is devoted to discussing the method of measuring the accumulation of radioactive isotopes 53Mn (with a half-life T = 3.7 million years) and 10Be ( T = 2.5 million years) in iron-bearing rocks. Knowledge of the dynamics of the accumulation of these isotopes would allow us to estimate the variations in the intensity of cosmic rays, periods of glaciations and geological changes, as well as climatic processes on the Earth in retrospect of 0.1-10 million years. For an operative study of a large number of samples, it has been proposed to use a low-cost neutron activation method with the implementation of the 53Mn( n, γ)54Mn reaction in a slow neutron reactor. As has been shown, using the 10Be isotope together with 53Mn makes it possible to simultaneously determine both the cosmic-ray fluxes and the shielding time of the corresponding region from cosmic radiation. To obtain the reliable data on cosmic rays, it has been proposed to study rock samples from the lunar surface.

  20. Evidence from Voyager and ISEE-3 spacecraft. Data for the decay of secondary K-electron capture isotopes during the propagation of cosmic rays in the Galaxy

    NASA Astrophysics Data System (ADS)

    Soutoul, A.; Legrain, R.; Lukasiak, A.; McDonald, F. B.; Webber, W. R.

    1998-08-01

    New data from the cosmic ray experiment on the Voyager spacecraft confirms and extends earlier data from a similar experiment on the ISEE-3 spacecraft which indicates the possibility of the decay of certain K-capture isotopes during the interstellar propagation of galactic cosmic rays. These cosmic ray measurements, along with the cross section measurements, indicate that ~ 25% of the K-capture isotopes (51Cr and (49V produced as secondaries have decayed at interstellar energy of ~ 400 MeV/nuc. This suggests a possible interstellar energy gain ~ 100 MeV/nuc out of the current interstellar energy ~ 500 MeV/nuc. This measurement suggests that the study of the K-capture isotopes may now have reached a level that will soon provide definitive information on the amount of re-acceleration that may occur during cosmic-ray propagation after an initial acceleration in the cosmic ray sources.

  1. Are Scaling Models for Production of Cosmogenic Nuclides Isotope Specific? - Implications from Secondary Cosmic Ray Neutron Spectra Measurements

    NASA Astrophysics Data System (ADS)

    Wilcken, K.

    2015-12-01

    A necessary requirement in studies using in-situ cosmogenic isotopes is to convert the measured isotope concentrations to exposure ages or geomorphic process rates. This involves using an accepted reference production rate, derived experimentally at a calibration site that has independent age control, and applying scaling factors for latitude and altitude in order to calculate a site-specific production rate. Throughout the development of the in-situ cosmogenic dating method, although reference production rates are necessarily nuclide specific, the scaling factors were not. The first atmospheric scaling model by Lal and Peters [1967] and others that followed, were based on the principle that as the cosmic ray particle flux attenuates with depth, the energy spectrum of nucleons of energy below 400 MeV becomes invariant at atmospheric depths greater than 200 g/cm2(altitude < 12 km). Hence scaling factors would thus be isotope independent resulting in production rate ratios of different isotopes to be invariant as a function of altitude. However, recent models by Argento et al. [2012, 2015] and Lifton et al. [2014] suggest that the energy spectrum is not invariant and scaling factors should in fact be isotope specific. The essential feature of the new models is that the focus is on generating the energy spectrum of cosmic-ray nucleons that is then converted into scaling factors with known cross sections. To benchmark the new scaling models I have collated secondary cosmic-ray neutron spectra measurements from the last 20 years and utilised these to calculate site-specific production rates. When using both ground-based and airborne neutron spectra measurements, the result follows the general trend predicted by the new models requiring isotope specific scaling. In contrast, using only the ground-based measurements, which range from sea-level to ~4000 m in altitude, no evidence for isotope specific scaling is apparent.

  2. 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.

  3. The source charge and isotopic abundances of cosmic rays with Z = 9-16 - A study using new fragmentation cross sections

    NASA Technical Reports Server (NTRS)

    Webber, W. R.; Gupta, M.; Soutoul, A.; Ferrando, P.

    1990-01-01

    The cosmic ray source charge and isotopic abundances for charges with Z = 9-16 are reexamined using newly measured fragmentation cross sections in a standard Galactic propagation model. Compared with earlier studies, the cosmic-ray data are now consistent with no excess of Si-29 and Si-30 in the source relative to the solar coronal abundances. The excess of Mg-25 and Mg-26 is now about 1 sigma or less relative to solar coronal isotopic abundances, leaving Ne-22 as the only clearly established neutron-rich isotopic excess in the cosmic ray source. Better estimates of the source abundances of elements obtained using the new cross sections permit the conclusion that high first ionization potential (FIP) elements have a wide spread of compositional differences in the cosmic-ray source relative to solar coronal abundances, whereas elements with a low FIP have a composition similar to the solar corona.

  4. A Cerenkov - Delta E/Delta X experiment for measuring cosmic-ray isotopes from neon through iron

    NASA Technical Reports Server (NTRS)

    Buffington, A.; Lau, K.; Schindler, S. M.; Stone, E. C.; Laursen, S.; Rasmussen, I. L.

    1983-01-01

    Cosmic-ray isotope masses are measured in a balloon-borne cosmic-ray experiment. Two Cerenkov counters and an NaI scintillator stack are used to determine changes in energy and in the Lorentz factor for a traversing or stopping particle. The mass is defined at the ratio of the change in energy to the change in the Lorentz factor. For incident elements from neon through iron, mass resolution better than 0.3 a.m.u. is expected, with incident Lorentz gammas ranging from 2.4 to 3.1, depending on the element. The mass resolution is approximately 0.2 a.m.u., measured for Mn-55 ions having an incident Lorentz factor of 2.75.

  5. High-resolution observations of the isotopic composition of carbon and silicon in the galactic cosmic rays

    NASA Technical Reports Server (NTRS)

    Wiedenbeck, M. E.; Greiner, D. E.

    1981-01-01

    High resolution satellite observations of the galactic cosmic rays (approximately 100-300 MeV/amu) have yielded determinations of near-earth isotopic compositions, which are presented: (C-13)/(C-12) = 0.070 + or - 0.006; (Si-29)/(Si-28) = 0.109(+0.024, -0.014); and (Si-30)/(Si-28) = 0.084(+0.020, -0.014). Using a standard propagation model, source values greater than solar are derived for each of these ratios. The (C-13) excess may be the result of cross section uncertainties, but the (Si-29) and (Si-30) appear to reflect real differences between the galactic cosmic-ray source and the solar system.

  6. 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.

  7. Cosmic ray isotope measurements with a new Cerenkov X total energy telescope

    NASA Technical Reports Server (NTRS)

    Webber, W. R.; Kish, J. C.; Schrier, D. A.

    1985-01-01

    Measurements of the isotopic composition of cosmic nuclei with Z = 7-20 are reported. These measurements were made with a new version of a Cerenkov x total E telescope. Path length and uniformity corrections are made to all counters to a RMS level 1%. Since the Cerenkov counter is crucial to mass measurements using the C x E technique - special care was taken to optimize the resolution of the 2.4 cm thick Pilot 425 Cerenkov counter. This counter exhibited a beta = 1 muon equivalent LED resolution of 24%, corresponding to a total of 90 p.e. collected at the 1st dynodes of the photomultiplier tubes.

  8. Energy Spectrum and Time Variations of Cosmic-Ray Hydrogen and Helium Isotopes with BESS-Polar II

    NASA Astrophysics Data System (ADS)

    Picot-Clemente, Nicolas

    The Balloon-Borne Experiment with a Superconducting Spectrometer (BESS-Polar II) flew successfully over Antarctica for 24.5 days in December 2007 through January 2008 during a period of minimum solar activity. BESS-Polar II is configured with a solenoidal superconducting magnet and a suite of precision particle detectors. It can accurately identify hydrogen and helium isotopes among the incoming cosmic-ray nuclei with energies from 0.2 up to about 1.5 GeV/n. The long duration of the flight, and the good stability of the detectors increased the number of cosmic-ray events previously recorded with BESS-Polar I by a factor of 5, reaching about 4.7 billion collected particles. This allows to study and measure energy spectrum and time variations of hydrogen and helium isotope fluxes with unprecedented precision. The isotope flux and ratio measurements with BESS-Polar II will be presented and compared to various propagation models. The time variations will also be presented along with the corresponding solar activity during the data taking period.

  9. 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.

  10. 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.

  11. A study of galactic cosmic ray propagation models based on the isotopic composition of the elements lithium, beryllium and boron

    NASA Technical Reports Server (NTRS)

    Hinshaw, G. F.; Wiedenbeck, M. E.; Greiner, D. E.

    1982-01-01

    A good test for a cosmic ray propagation model is its ability to predict the abundances of the light secondary nuclei lithium, beryllium, and boron. By using measured isotopic abundances of lithium, beryllium, and boron, Garcia-Munoz et al. (1979) were able to place limits on three important parameters of a leaky box propagation model. The considered parameters include the source spectral parameter, the leakage mean free path, and the characteristic adiabatic energy loss due to solar modulation. The present investigation is concerned with a critical evaluation of the information which can be deduced about these parameters from isotopic composition alone, taking into account the effects of uncertainties in the spallation cross section data.

  12. A study of galactic cosmic ray propagation models based on the isotopic composition of the elements lithium, beryllium and boron

    NASA Technical Reports Server (NTRS)

    Hinshaw, G. F.; Wiedenbeck, M. E.; Greiner, D. E.

    1982-01-01

    A good test for a cosmic ray propagation model is its ability to predict the abundances of the light secondary nuclei lithium, beryllium, and boron. By using measured isotopic abundances of lithium, beryllium, and boron, Garcia-Munoz et al. (1979) were able to place limits on three important parameters of a leaky box propagation model. The considered parameters include the source spectral parameter, the leakage mean free path, and the characteristic adiabatic energy loss due to solar modulation. The present investigation is concerned with a critical evaluation of the information which can be deduced about these parameters from isotopic composition alone, taking into account the effects of uncertainties in the spallation cross section data.

  13. A balloon measurement of the isotopic composition of galactic cosmic ray boron, carbon and nitrogen. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Zumberge, J. F.

    1981-01-01

    The isotopic compositions of galactic cosmic ray boron, carbon, and nitrogen were measured at energies near 300 MeV amu, using a balloon-borne instrument at an atmospheric depth of approximately 5 g/sq cm. The calibrations of the detectors comprising the instrument are described. The saturation properties of the cesium iodide scintillators used for measurement of particle energy are studied in the context of analyzing the data for mass. The achieved rms mass resolution varies from approximately 0.3 amu at boron to approximately 0.5 amu at nitrogen, consistent with a theoretical analysis of the contributing factors. Corrected for detector interactions and the effects of the residual atmosphere the results are B-10/B=0.33 (+0.17, -0.11), C-13/C=0.06 (+0.13, -0.11), and N-15/N=0.42 (+0.19, -0.17). A model of galactic propagation and solar modulation is described. Assuming a cosmic ray source composition of solar-like isotopic abundances, the model predicts abundances near Earth consistent with the measurements.

  14. Isotopic Evidence for Multi-stage Cosmic-ray Exposure Histories of Lunar Meteorites: Long Residence on the Moon and Short Transition to the Earth

    NASA Astrophysics Data System (ADS)

    Hidaka, Hiroshi; Sakuma, Keisuke; Nishiizumi, Kunihiko; Yoneda, Shigekazu

    2017-06-01

    It is known that most lunar meteorites have complicated cosmic-ray exposure experiences on the Moon and in space. In this study, cosmic-ray irradiation histories of six lunar meteorites, Dhofar 489, Northwest Africa 032 (NWA 032), NWA 479, NWA 482, NWA 2995, and NWA 5000, were characterized from neutron-captured isotopic shifts of Sm and Gd, and from the abundances of long-lived cosmogenic radionuclides like 10Be, 26Al, 36Cl, and 41Ca. Sm and Gd isotopic data of all of six meteorites show significant isotopic shifts of 149Sm-150Sm and 157Gd-158Gd caused by accumulation of neutron capture reactions due to cosmic-ray irradiation, corresponding to the neutron fluences of (1.3-9.6) × 1016 n cm-2. In particular, very large Sm and Gd isotopic shifts of NWA 482 are over those of a lunar regolith 70002, having the largest isotopic shifts among the Apollo regolith samples, corresponding to cosmic-ray exposure duration over 800 million years in the lunar surface (2π irradiation). Meanwhile, the concentrations of cosmogenic radionuclides for individual six meteorites show the short irradiation time less than one million years as their bodies in space (4π irradiation). Our data also support the results of previous studies, revealing that most of lunar meteorites have long exposure ages at shallow depths on the Moon and short transit times from the Moon to the Earth.

  15. 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.

  16. Deuterium and He-3 in cosmic rays

    NASA Technical Reports Server (NTRS)

    Stephens, S. A.

    1989-01-01

    Observation of a large flux of antiprotons in cosmic rays prompted many to postulate new ideas relating to the origin and propagation of cosmic rays in the Galaxy, within the framework of the secondary hypothesis. Under this hypothesis, cosmic rays traverse a large amount of matter either in the source region or in the interstellar space. As a result, large amounts of deuterium and He-3 are also produced as a consequence of spallation of helium and heavier nuclei. In this paper, the spectra of these isotopes are derived, using various models for the propagation of cosmic rays and compare with the existing observations.

  17. The cosmic ray and solar flare isotope experiments in the CRRES, NOAA-I and Ulysses'' satellites

    SciTech Connect

    Garcia-Munoz, M. )

    1990-03-20

    The ONR-604 instrument has been designed to measure the energy spectra and the isotopic composition at 1 AU of the elements Hydrogen to Nickel in the energy range 40--500 MeV/n and will be carried by the Combined Release and Radiation Effects Satellite (CRRES) to be launched July, 1990 in a highly eccentric orbit between a low perigee and a synchronous orbit point. It will measure galactic cosmic rays, solar energetic particles, and trapped and pseudo-trapped particles in the Earth magnetosphere. Also at 1 AU, the Energetic Heavy Ion Composition (EHIC) instrument, designed to study mainly the elemental and isotopic composition of solar energetic particles over the charge range H to Ni, in the energy range 0.5 to 200 MeV/n, will be placed in a Sun-synchronous circular polar orbit of 833 or 870 km altitude by a NOAA-I satellite scheduled to be launched late 1990 or early 1991. The University of Chicago High Energy Telescope (HET) experiment which is part of the COSPIN consortium on the Ulysses'' mission will measure the energy spectra and the isotopic composition of the elments Hydrogen to Nickel in the energy interval 20--450 MeV/n in the heliosphere, both the ecliptic plane and at high heliographic latitudes in an orbit around the Sun that will have an aphelion near a Jupiter orbit point and a perhelion of about 1.4 AU. It will be launched October 1990.

  18. First measurement of radioactive isotope production through cosmic-ray muon spallation in Super-Kamiokande IV

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Abe, K.; Haga, Y.; Hayato, Y.; Ikeda, M.; Iyogi, K.; Kameda, J.; Kishimoto, Y.; Miura, M.; Moriyama, S.; Nakahata, M.; Nakajima, T.; Nakano, Y.; Nakayama, S.; Orii, A.; Sekiya, H.; Shiozawa, M.; Takeda, A.; Tanaka, H.; Tomura, T.; Wendell, R. A.; Irvine, T.; Kajita, T.; Kametani, I.; Kaneyuki, K.; Nishimura, Y.; Richard, E.; Okumura, K.; Labarga, L.; Fernandez, P.; Gustafson, J.; Kachulis, C.; Kearns, E.; Raaf, J. L.; Stone, J. L.; Sulak, L. R.; Berkman, S.; Nantais, C. M.; Tanaka, H. A.; Tobayama, S.; Goldhaber, M.; Carminati, G.; Griskevich, N. J.; Kropp, W. R.; Mine, S.; Renshaw, A.; Smy, M. B.; Sobel, H. W.; Takhistov, V.; Weatherly, P.; Ganezer, K. S.; Hartfiel, B. L.; Hill, J.; Hong, N.; Kim, J. Y.; Lim, I. T.; Himmel, A.; Li, Z.; Scholberg, K.; Walter, C. W.; Wongjirad, T.; Ishizuka, T.; Tasaka, S.; Jang, J. S.; Learned, J. G.; Matsuno, S.; Smith, S. N.; Friend, M.; Hasegawa, T.; Ishida, T.; Ishii, T.; Kobayashi, T.; Nakadaira, T.; Nakamura, K.; Oyama, Y.; Sakashita, K.; Sekiguchi, T.; Tsukamoto, T.; Suzuki, A. T.; Takeuchi, Y.; Yano, T.; Hirota, S.; Huang, K.; Ieki, K.; Kikawa, T.; Minamino, A.; Nakaya, T.; Suzuki, K.; Takahashi, S.; Fukuda, Y.; Choi, K.; Itow, Y.; Suzuki, T.; Mijakowski, P.; Frankiewicz, K.; Hignight, J.; Imber, J.; Jung, C. K.; Li, X.; Palomino, J. L.; Wilking, M. J.; Yanagisawa, C.; Ishino, H.; Kayano, T.; Kibayashi, A.; Koshio, Y.; Mori, T.; Sakuda, M.; Kuno, Y.; Tacik, R.; Kim, S. B.; Okazawa, H.; Choi, Y.; Nishijima, K.; Koshiba, M.; Suda, Y.; Totsuka, Y.; Yokoyama, M.; Bronner, C.; Hartz, M.; Martens, K.; Marti, Ll.; Suzuki, Y.; Vagins, M. R.; Martin, J. F.; de Perio, P.; Konaka, A.; Chen, S.; Wilkes, R. J.; Super-Kamiokande Collaboration

    2016-01-01

    Cosmic-ray-muon spallation-induced radioactive isotopes with β decays are one of the major backgrounds for solar, reactor, and supernova relic neutrino experiments. Unlike in scintillator, production yields for cosmogenic backgrounds in water have not been exclusively measured before, yet they are becoming more and more important in next generation neutrino experiments designed to search for rare signals. We have analyzed the low-energy trigger data collected at Super-Kamiokande IV in order to determine the production rates of 12B, 12N, 16N, 11Be, 9Li, 8He, 9C, 8Li, 8B, and 15C. These rates were extracted from fits to time differences between parent muons and subsequent daughter β 's by fixing the known isotope lifetimes. Since >9Li can fake an inverse-beta-decay reaction chain via a β +n cascade decay, producing an irreducible background with detected energy up to a dozen MeV, a dedicated study is needed for evaluating its impact on future measurements; the application of a neutron tagging technique using correlated triggers was found to improve this 9Li measurement. The measured yields were generally found to be comparable with theoretical calculations, except the cases of the isotopes 9Li / 8B and 9Li.

  19. Cosmic Ray Astronomy

    NASA Technical Reports Server (NTRS)

    Wu, S. T.

    2000-01-01

    The cosmic ray division participation in the cooperative agreement was activated in the second year. The scientific goals will be analysis of cosmic ray data from the Japanese-American Cooperative Emulsion Experiments (JACEE). Measurements of primary cosmic rays in the JACEE emulsion chambers will be made to derive for each detected particle the deposited energy in the chamber and the primary charge (atomic number). The data will be corrected to the primary flux above the atmosphere, and the composition and energy spectra will be derived. The spectra of the individual elements will be interpreted in context with the supernova shock and other models of cosmic ray acceleration. Additional information is contained in the original extended abstract.

  20. Production of the cosmogenic isotopes 3H, 7Be, 10Be, and 36Cl in the Earth's atmosphere by solar and galactic cosmic rays

    NASA Astrophysics Data System (ADS)

    Webber, W. R.; Higbie, P. R.; McCracken, K. G.

    2007-10-01

    In a follow-up study to the earlier work of Webber and Higbie (2003) on 10Be production in the Earth's atmosphere by cosmic rays, we have calculated the atmospheric production of the cosmogenic isotopes 3H, 7Be, 10Be, and 36Cl using the FLUKA Monte Carlo code. This new calculation of atmospheric yields of these isotopes is based on 107 vertically incident protons at each of 24 logarithmically spaced energies from 10 MeV to 10 GeV, 102 times the number used in the earlier calculation, along with the latest cross sections. This permits a study of the production due to solar cosmic rays as well as galactic cosmic rays at lower energies where isotope production is a very sensitive function of energy. Solar cosmic ray spectra are reevaluated for all of the major events occurring since 1956. In terms of yearly production of 10Be, only the February 1956 solar event makes a major contribution. For 36Cl these yearly SCR production contributions are 2-5 times larger depending on the solar cosmic ray energy spectra. We have determined the yearly production of 10Be, 36Cl, and other cosmogenic isotopes above 65° geomagnetic latitude for the time period 1940-2006 covering six solar 11-year (a) cycles. The average peak-to-peak 11-a amplitude of this yearly production is 1.77. The effects of latitudinal mixing alter these direct polar production values considerably, giving an average peak-to-peak 11-a amplitude of 1.48 for the global average production.

  1. Cosmic-ray exposure histories of Martian meteorites studied from neutron capture reactions of Sm and Gd isotopes

    NASA Astrophysics Data System (ADS)

    Hidaka, Hiroshi; Yoneda, Shigekazu; Nishiizumi, Kunihiko

    2009-11-01

    The isotopic compositions of Sm and Gd in twelve Martian meteorites, ALH 77005, ALH 84001, DaG 735, Dhofar 019, EET 79001, Lafayette, Los Angeles, Nakhla, SaU 005, Y 000593, Y 000749 and Zagami, were determined to quantify the neutron capture records of individual meteorite specimens. Seven of these twelve samples, ALH 84001, Y 000749, DaG 735, Dhofar 019, EET 79001, SaU 005 and Zagami, showed significant isotopic shifts of 150Sm/ 149Sm and/or 158Gd/ 157Gd corresponding to neutron fluences of (0.7-3.4) × 10 15 n cm - 2 . Among these seven meteorites, the neutron fluences of ALH 84001, Y 000749, and Dhofar 019 apparently correlated with their cosmic-ray exposure ages, indicating that most of the irradiation took place while the meteoroids were small bodies in space after the ejection from Mars. However, our results suggest an accumulation of their inherited irradiation occurred on Mars. On the other hand, the exposure histories of the other four meteorites (basaltic shergottites), DaG 735, EET 79001, SaU 005, and Zagami, cannot be explained as single- or multistage irradiations in space, or as a single irradiation on the Martian surface. The mixing between basaltic lava with a significantly irradiated Martian regolith is a reasonable interpretation of the excess neutron capture records observed in these four basaltic shergottites.

  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. Experiments to study cosmic ray isotopic composition up to Zr-40

    NASA Technical Reports Server (NTRS)

    Milliken, Barrett

    1990-01-01

    An overview is presented of instruments and techniques being developed with improved mass resolution and large geometry factor for the study of isotopes. The Advanced Composition Explorer and the Large-Isotope Spectrometer for Astromag are presented as two experiment systems that can reduce statistical uncertainty for the iron isotopes to a small percentage. The instruments are capable of studying isotopes with values of Z of 30-40 by means of orbiting or lunar-based platforms when used for long-duration exposure.

  4. Supernova and cosmic rays

    NASA Technical Reports Server (NTRS)

    Wefel, J. P.

    1981-01-01

    A general overview of supernova astronomy is presented, followed by a discussion of the relationship between SN and galactic cosmic rays. Pre-supernova evolution is traced to core collapse, explosion, and mass ejection. The two types of SN light curves are discussed in terms of their causes, and the different nucleosynthetic processes inside SNs are reviewed. Physical events in SN remnants are discussed. The three main connections between cosmic rays and SNs, the energy requirement, the acceleration mechanism, and the detailed composition of CR, are detailed.

  5. 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.

  6. Cosmic ray antiprotons from nearby cosmic accelerators

    NASA Astrophysics Data System (ADS)

    Joshi, Jagdish C.; Gupta, Nayantara

    2015-05-01

    The antiproton flux measured by PAMELA experiment might have originated from Galactic sources of cosmic rays. These antiprotons are expected to be produced in the interactions of cosmic ray protons and nuclei with cold protons. Gamma rays are also produced in similar interactions inside some of the cosmic accelerators. We consider a few nearby supernova remnants observed by Fermi LAT. Many of them are associated with molecular clouds. Gamma rays have been detected from these sources which most likely originate in decay of neutral pions produced in hadronic interactions. The observed gamma ray fluxes from these SNRs are used to find out their contributions to the observed diffuse cosmic ray antiproton flux near the earth.

  7. The Effects of Galatic Cosmic Ray Irradiation on Palladium Isotopes in Iron Meteorites

    NASA Astrophysics Data System (ADS)

    Ek, M.; Hunt, A. C.; Schönbächler, M.

    2015-07-01

    New Pd isotope data of IAB, IIAB, IVA and IVB iron meteorites are presented. Preliminary results suggest correlated variations in 104Pd and the more established Pt dosimeter as well as the absence of nucleosynthetic anomalies in IAB meteorites.

  8. 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.

  9. Cosmic Rays at Earth

    NASA Astrophysics Data System (ADS)

    Grieder, P. K. F.

    In 1912 Victor Franz Hess made the revolutionary discovery that ionizing radiation is incident upon the Earth from outer space. He showed with ground-based and balloon-borne detectors that the intensity of the radiation did not change significantly between day and night. Consequently, the sun could not be regarded as the sources of this radiation and the question of its origin remained unanswered. Today, almost one hundred years later the question of the origin of the cosmic radiation still remains a mystery. Hess' discovery has given an enormous impetus to large areas of science, in particular to physics, and has played a major role in the formation of our current understanding of universal evolution. For example, the development of new fields of research such as elementary particle physics, modern astrophysics and cosmology are direct consequences of this discovery. Over the years the field of cosmic ray research has evolved in various directions: Firstly, the field of particle physics that was initiated by the discovery of many so-called elementary particles in the cosmic radiation. There is a strong trend from the accelerator physics community to reenter the field of cosmic ray physics, now under the name of astroparticle physics. Secondly, an important branch of cosmic ray physics that has rapidly evolved in conjunction with space exploration concerns the low energy portion of the cosmic ray spectrum. Thirdly, the branch of research that is concerned with the origin, acceleration and propagation of the cosmic radiation represents a great challenge for astrophysics, astronomy and cosmology. Presently very popular fields of research have rapidly evolved, such as high-energy gamma ray and neutrino astronomy. In addition, high-energy neutrino astronomy may soon initiate as a likely spin-off neutrino tomography of the Earth and thus open a unique new branch of geophysical research of the interior of the Earth. Finally, of considerable interest are the biological

  10. Measurement of the Galactic Cosmic Ray Antiproton Flux from 0.25 GEV to 3.11 GEV with the Isotope Matter Antimatter Experiment (IMAX)

    NASA Astrophysics Data System (ADS)

    Labrador, Allan Wayne

    1997-07-01

    The galactic cosmic ray proton and antiproton abundances were measured with the Isotope Matter Antimatter Experiment (IMAX), a balloon-borne magnet spectrometer. IMAX flew from Lynn Lake, Manitoba, Canada on July 16, 1992. Particles detected by IMAX were identified via the Cherenkov-Rigidity and TOF-Rigidity techniques, with measured mass resolution <=0.2 amu for Z = 1 particles. Previous cosmic ray antiproton experiments reported more antiprotons than expected from high energy cosmic ray interactions with the interstellar medium. IMAX data analysis yielded 124405 protons and 3 antiprotons in the energy range 0.19-0.97 GeV at the instrument, 140617 protons and 8 antiprotons at 0.97-2.58 GeV, and 22524 protons and 5 antiprotons at 2.58-3.08 GeV. These measurements are a statistical improvement over previous measurements, and they demonstrate improved separation of antiprotons from protons, electrons, and other cosmic ray species. When corrected for instrumental and atmospheric background and losses, the ratios at the top of the atmosphere are p/p = 3.21 (+3.49, -1.97)× 10-5 in the energy range 0.25-1.00 GeV, p/p = 5.38 (+3.48, -2.45)× 10-5 at 1.00-2.61 GeV, and p/p = 2.05 (+1.79, -1.15)× 10-4 at 2.61-3.11 GeV. The corresponding antiproton intensities are 2.3 (+2.5, -1.4)× 10-2 (m2 s sr GeV)-1, 2.1 (+1.4, -1.0)× 10-2 (m2 s sr GeV)-1, and 4.3 (+3.7, -2.4)× 10-2 (m2 s sr GeV)-1. The IMAX antiproton fluxes and antiproton/proton ratios are compared with recent Standard Leaky Box Model (SLBM) calculations, in which cosmic ray antiprotons arise solely from high energy cosmic ray interactions with the interstellar medium. Solar modulation effects are also calculated, showing that the antiproton/proton ratio can vary by an order of magnitude over the solar cycle. The IMAX antiproton measurements are consistent with recent calculations of the SLBM and solar modulation. No evidence is found in the IMAX data for excess antiprotons arising from exotic sources. Furthermore

  11. 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)

  12. Spaced-based Cosmic Ray Astrophysics

    NASA Astrophysics Data System (ADS)

    Seo, Eun-Suk

    2016-03-01

    The bulk of cosmic ray data has been obtained with great success by balloon-borne instruments, particularly with NASA's long duration flights over Antarctica. More recently, PAMELA on a Russian Satellite and AMS-02 on the International Space Station (ISS) started providing exciting measurements of particles and anti-particles with unprecedented precision upto TeV energies. In order to address open questions in cosmic ray astrophysics, future missions require spaceflight exposures for rare species, such as isotopes, ultra-heavy elements, and high (the ``knee'' and above) energies. Isotopic composition measurements up to about 10 GeV/nucleon that are critical for understanding interstellar propagation and origin of the elements are still to be accomplished. The cosmic ray composition in the knee (PeV) region holds a key to understanding the origin of cosmic rays. Just last year, the JAXA-led CALET ISS mission, and the DAMPE Chinese Satellite were launched. NASA's ISS-CREAM completed its final verification at GSFC, and was delivered to KSC to await launch on SpaceX. In addition, a EUSO-like mission for ultrahigh energy cosmic rays and an HNX-like mission for ultraheavy nuclei could accomplish a vision for a cosmic ray observatory in space. Strong support of NASA's Explorer Program category of payloads would be needed for completion of these missions over the next decade.

  13. Interstellar propagation and the isotopic composition of hydrogen in the galactic cosmic rays

    NASA Technical Reports Server (NTRS)

    Beatty, J. J.

    1985-01-01

    Preliminary results of a study of the propagation of the quartet of stable isotopes of hydrogen and helium are reported. A mean pathlength of 7.5 + or - 0.5 g/sq cms at approximately 300 MeV/nucleon is required to explain the low energy deuterium spectrum. This pathlength is consistent with pathlengths derived from the elements with Z 2, but is a (He-3/He-4) measurement of Jordan and P. Meyer (1984). The propagation calculations reported here incorporate the preliminary results of an updated nuclear interaction cross section survey covering the period since the review by J. P. Meyer (1972).

  14. 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.

  15. 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.; hide

    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.

  16. Dark cosmic rays

    DOE PAGES

    Hu, Ping-Kai; Kusenko, Alexander; Takhistov, Volodymyr

    2017-02-22

    If dark matter particles have an electric charge, as in models of millicharged dark matter, such particles should be accelerated in the same astrophysical accelerators that produce ordinary cosmic rays, and their spectra should have a predictable rigidity dependence. Depending on the charge, the resulting “dark cosmic rays” can be detected as muon-like or neutrino-like events in Super-Kamiokande, IceCube, and other detectors. We present new limits and propose several new analyses, in particular, for the Super-Kamiokande experiment, which can probe a previously unexplored portion of the millicharged dark matter parameter space. Here, most of our results are fairly general andmore » apply to a broad class of dark matter models.« less

  17. 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.

  18. Cosmic ray driven Galactic winds

    NASA Astrophysics Data System (ADS)

    Recchia, S.; Blasi, P.; Morlino, G.

    2016-11-01

    The escape of cosmic rays from the Galaxy leads to a gradient in the cosmic ray pressure that acts as a force on the background plasma, in the direction opposite to the gravitational pull. If this force is large enough to win against gravity, a wind can be launched that removes gas from the Galaxy, thereby regulating several physical processes, including star formation. The dynamics of these cosmic ray driven winds is intrinsically non-linear in that the spectrum of cosmic rays determines the characteristics of the wind (velocity, pressure, magnetic field) and in turn the wind dynamics affects the cosmic ray spectrum. Moreover, the gradient of the cosmic ray distribution function causes excitation of Alfvén waves, that in turn determines the scattering properties of cosmic rays, namely their diffusive transport. These effects all feed into each other so that what we see at the Earth is the result of these non-linear effects. Here, we investigate the launch and evolution of such winds, and we determine the implications for the spectrum of cosmic rays by solving together the hydrodynamical equations for the wind and the transport equation for cosmic rays under the action of self-generated diffusion and advection with the wind and the self-excited Alfvén waves.

  19. The Origin of Cosmic Rays

    ScienceCinema

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

    2016-07-12

    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.

  20. Dispersion of the ratios of cosmogenic isotopes of noble gases in chondrites of different cosmic-ray exposure ages

    NASA Technical Reports Server (NTRS)

    Alexeev, V. A.

    1993-01-01

    The dispersion of ratios of (He-3/Ne-21)c and (Ne-22/Ne-21)c depending on the cosmic-ray exposure ages of meteorites is analyzed. The dispersion is increased as age decreases. This effect may be stipulated by presence of a more significant portion of meteorites of small preatmospheric sizes among meteorites of small radiation ages in comparison to meteorites of higher exposure age.

  1. Isotopic measurements of the cosmic ray nuclei at 1.7 GeV/n and 0.5 GeV/n

    NASA Technical Reports Server (NTRS)

    Juliusson, E.

    1975-01-01

    Results are presented on the mean isotopic composition of cosmic ray nuclei, or the average neutron excess for the elements Be to Si. At 1.7 GeV/nucleon they have been obtained by comparing the abundances measured above a rigidity threshold at Palestine, Texas, with abundances measured above an equivalent velocity threshold at Cape Girardeau Missouri. At 0.5 GeV/nucleon the results are obtained by analysing the variation in the chemical composition with energy in the energy region around the geomagnetic cut-off.

  2. Propagation of heavy cosmic-ray nuclei

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    Techniques for modeling the propagation of heavy cosmic-ray nuclei, and the required atomic and nuclear data, are assembled in this paper. Emphasis is on understanding nuclear composition in the charge range Z = 3-83. Details of the application of 'matrix methods' above a few hundred MeV/nucleon, a new treatment of electron capture decay, and a new table of cosmic ray-stable isotopes are presented. Computation of nuclear fragmentation cross sections, stopping power, and electron stripping and attachment are briefly reviewed.

  3. 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.

  4. 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.

  5. 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.

  6. Cosmic Ray Neutron Flux Measurements

    NASA Astrophysics Data System (ADS)

    Dayananda, Mathes

    2009-11-01

    Cosmic rays are high-energetic particles originating from outer space that bombard the upper atmosphere of the Earth. Almost 90% of cosmic ray particles consist of protons, electrons and heavy ions. When these particles hit the Earth's atmosphere, cascade of secondary particles are formed. The most abundant particles reach to the surface of the Earth are muons, electrons and neutrons. In recent years many research groups are looking into potential applications of the effects of cosmic ray radiation at the surface of the Earth [1, 2]. At Georgia State University we are working on a long-term measurement of cosmic ray flux distribution. This study includes the simultaneous measurement of cosmic ray muons, neutrons and gamma particles at the Earth surface in downtown Atlanta. The initial effort is focusing on the correlation studies of the cosmic ray particle flux distribution and the atmospheric weather conditions. In this presentation, I will talk about the development of a cosmic ray detector using liquid scintillator and the preliminary results. [4pt] [1] K.Borozdin, G.Hogan, C.Morris, W.Priedhorsky, A.Saunders, L.Shultz, M.Teasdale, ``Radiographic imaging with cosmic-ray muons'', Nature, Vol.422, p.277, Mar.2003[0pt] [2] Svensmark Henrik, Physical Review 81, 3, (1998)

  7. Cosmic Rays and Experiment CZELTA

    SciTech Connect

    Smolek, Karel; Nyklicek, Michal

    2007-11-26

    This paper gives a review of the physics of cosmic rays with emphasis on the methods of detection and study. A summary is given of the Czech project CZELTA which is part of a multinational program to study cosmic rays with energies above 10{sup 14} eV.

  8. Cosmic ray hazards in the solar system.

    NASA Technical Reports Server (NTRS)

    Milford, S. N.

    1965-01-01

    Cosmic ray hazards in solar system considered from measurements of cosmic ray energy and charge spectra near Earth and in interplanetary space near Earth, together with interaction of cosmic rays with Moon surface

  9. Cosmic Ray Physics at CERN

    NASA Astrophysics Data System (ADS)

    Fernandéz, A.; Gámez, E.; López, R.; Román, S.; Zepeda, A.

    2003-06-01

    In recent decades, cosmic ray air showers initiated by high-energy proton or nucleus collisions in the atmosphere have been studied with large area experiments on the surface of the Earth or with muon measurements deep underground. In principle, these cosmic ray experiments explore two completely different realms of physics, particle astrophysics and particle interaction physics, which are, however, intimately related by the interpretation of the data. In this paper we briefly review the cosmic ray physics activities developed at CERN in the last years. In particular we present some results from a small underground cosmic ray experiment and we discuss the capabilities of ALICE to detect high multiplicity muon events arising from cosmic ray air showers and some other astroparticle phenomena.

  10. 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.

  11. 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.

  12. Cosmic Ray Scattering Radiography

    NASA Astrophysics Data System (ADS)

    Morris, C. L.

    2015-12-01

    Cosmic ray muons are ubiquitous, are highly penetrating, and can be used to measure material densities by either measuring the stopping rate or by measuring the scattering of transmitted muons. The Los Alamos team has studied scattering radiography for a number of applications. Some results will be shown of scattering imaging for a range of practical applications, and estimates will be made of the utility of scattering radiography for nondestructive assessments of large structures and for geological surveying. Results of imaging the core of the Toshiba Nuclear Critical Assembly (NCA) Reactor in Kawasaki, Japan and simulations of imaging the damaged cores of the Fukushima nuclear reactors will be presented. Below is an image made using muons of a core configuration for the NCA reactor.

  13. New Constraints on Cosmic-Ray Propagation Models using Hydrogen and Helium Isotope Measurements from the BESS-Polar II Experiment

    NASA Astrophysics Data System (ADS)

    Picot-Clemente, Nicolas; BESS-Polar Collaboration

    2016-03-01

    Deuterium 2 H and Helium 3 3He cosmic rays are mainly secondary particles produced by the spallation of Helium 4 nuclei (4He), or by the fusion of Hydrogen 1 H , after interacting in the interstellar medium during their propagation. As for the well-known Boron-to-Carbon ratio B/C, the secondary-to-primary ratios of 2 H/1 H , 2 H/4He and 3He/4He bring essential information to better understand the propagation of cosmic rays in the Galaxy. BESS-Polar II is a balloon-borne experiment that flew over Antarctica during the 23rd solar cycle minimum in December 2007 through January 2008 for 24.5 days. The instrument is a superconducting magnet spectrometer made of multiple particle detectors capable of precisely separating hydrogen and helium isotopes from 0.2 GeV/nucleon to 1.5 GeV/nucleon. The latest isotope measurements from BESS-Polar II, which are the most precise to date, will be presented and compared to other experiments. The GALPROP program will be used to emphasize the new constraints that these results bring on propagation models and parameters.

  14. The isotopic composition of cosmic-ray helium from 123 to 279 MeV per nucleon - A new measurement and analysis

    NASA Technical Reports Server (NTRS)

    Leech, H. W.; Ogallagher, J. J.

    1978-01-01

    A description is given of an experiment which was designed to measure the spectra and composition of cosmic-ray hydrogen and helium isotopes in the interval 120-280 MeV per nucleon to compare with the recent values observed at low energies and also with the only earlier measurement in this high-energy regime. The results presented were obtained during a high-altitude balloon flight from Thompson, Manitoba, in 1973 August. This flight occurred during the period in which the presence of the anomalous component in the helium spectrum became apparent, and provides the opportunity of determining whether this component extends to higher energies than those studied by satellite experiments. The results place an upper limit on the flux of 'anomalous' He-4 (which appeared at low energy in 1972) of at most 15% in the energy range of this experiment, and combined with the low-energy observations of the Chicago group, show an energy dependence of the average ratio of the helium isotopes in the modulated cosmic rays which is difficult to reconcile with current modulation models.

  15. Cosmic Ray Propagation and Acceleration

    NASA Technical Reports Server (NTRS)

    Moskalenko, Igor V.

    2003-01-01

    Theoretical views on particle acceleration in astrophysical sources and propagation of cosmic rays (CR) depend very much on the quality of the data, which become increasingly accurate each year and therefore more constraining. On the other hand, direct measurements of CR are possible in only one location on the outskirts of the Milky Way and present only a snapshot of very dynamic processes. The theoretical papers presented during the conference offer exciting insights into the physics of cosmic accelerators and processes which underlie the measured abundances and spectra of CR species. This paper is based on a rapporteur talk given at the 28th International Cosmic Ray Conference held on July 31-August 7, 2003 at Tsukuba. It covers the sessions OG 1.3 Cosmic ray propagation, OG 1.4 Acceleration of cosmic rays, and a part of HE 1.2 Theory and simulations (including origins of the knee).

  16. Cosmic Rays. Citations from the NTIS data base

    NASA Astrophysics Data System (ADS)

    Carrigan, B.

    1980-04-01

    Measurement techniques, isotopic composition, distribution, intensity, anisotropy, and sources of cosmic rays are covered in the citations. This updated bibliography contains 75 abstracts, 22 of which are new entries to the previous edition.

  17. 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.

  18. Cosmic rays in the heliosphere

    NASA Technical Reports Server (NTRS)

    Webber, William R.

    1987-01-01

    The different types of cosmic ray particles and their role in the heliosphere are briefly described. The rates of various energetic particles were examined as a function of time and used to derive various differential energy gradients. The Pioneer and Voyager cosmic ray observations throughout the heliosphere are indeed giving a perspective on the three-dimensional character and size of the heliosphere. Most clearly the observations are emphasizing the role that transient variations in the outer heliosphere, and most likely the heliospheric boundary shock, play in the 11 year solar cycle modulation of cosmic rays.

  19. Cosmic Rays and Particle Physics

    NASA Astrophysics Data System (ADS)

    Gaisser, Thomas K.; Engel, Ralph; Resconi, Elisa

    2016-06-01

    Preface to the first edition; Preface to the second edition; 1. Cosmic rays; 2. Cosmic ray data; 3. Particle physics; 4. Hadronic interactions and accelerator data; 5. Cascade equations; 6. Atmospheric muons and neutrinos; 7. Neutrino masses and oscillations; 8. Muons and neutrinos underground; 9. Cosmic rays in the Galaxy; 10. Extragalactic propagation of cosmic rays; 11. Astrophysical - rays and neutrinos; 12. Acceleration; 13. Supernovae in the Milky Way; 14. Astrophysical accelerators and beam dumps; 15. Electromagnetic cascades; 16. Extensive air showers; 17. Very high energy cosmic rays; 18. Neutrino astronomy; A.1. Units, constants and definitions; A.2. References to flux measurements; A.3. Particle flux, density, and interaction cross section; A.4. Fundamentals of scattering theory; A.5. Regge amplitude; A.6. Glauber model of nuclear cross sections; A.7. Earth's atmosphere; A.8. Longitudinal development of air showers; A.9. Secondary positrons and electrons; A.10. Liouville's theorem and cosmic ray propagation; A.11. Cosmology and distances measures; A.12. The Hillas splitting algorithm; References; Index.

  20. High energy cosmic ray composition

    NASA Astrophysics Data System (ADS)

    Seo, E. S.

    Cosmic rays are understood to result from energetic processes in the galaxy, probably from supernova explosions. However, cosmic ray energies extend several orders of magnitude beyond the limit thought possible for supernova blast waves. Over the past decade several ground-based and space-based investigations were initiated to look for evidence of a limit to supernova acceleration in the cosmic-ray chemical composition at high energies. These high-energy measurements are difficult because of the very low particle fluxes in the most interesting regions. The space-based detectors must be large enough to collect adequate statistics, yet stay within the weight limit for space flight. Innovative approaches now promise high quality measurements over an energy range that was not previously possible. The current status of high energy cosmic-ray composition measurements and planned future missions are discussed in this paper.

  1. Protostars: Forges of cosmic rays?

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

    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

  2. A new analysis of cosmic ray isotopes at 3 GeV/n from HEA03-C2 data

    NASA Technical Reports Server (NTRS)

    Ferrando, P.; Goret, P.; Koch-Miramond, L.; Petrou, N.; Soutoul, A.

    1985-01-01

    Results of mean masses of cosmic rays at energy about 3 GeV/n, for Ne, Al, Mg, Si, S, Ca, and Fe, derived from high energy astronomy observatory 3 data collected by the Danish-French experiment C2 on board (HEAO-3) are presented. A method based upon comparison between observed transmission function and a predicted one computed from a geomagnetic field model was used. Enhancement factors of 2.9 + or - .7 for 22Ne/20Ne, 2.1 + or - .4 for (25Mg+26Mg)/24Mg, and 1.6 + or - .8 for (29Si+30Si)/28Si at GCRS when compared to LG were found.

  3. Cosmic ray interactions in the ground: Temporal variations in cosmic ray intensities and geophysical studies

    NASA Technical Reports Server (NTRS)

    Lal, D.

    1986-01-01

    Temporal variations in cosmic ray intensity have been deduced from observations of products of interactions of cosmic ray particles in the Moon, meteorites, and the Earth. Of particular interest is a comparison between the information based on Earth and that based on other samples. Differences are expected at least due to: (1) differences in the extent of cosmic ray modulation, and (2) changes in the geomagnetic dipole field. Any information on the global changes in the terrestrial cosmic ray intensity is therefore of importance. In this paper a possible technique for detecting changes in cosmic ray intensity is presented. The method involves human intervention and is applicable for the past 10,000 yrs. Studies of changes over longer periods of time are possible if supplementary data on age and history of the sample are available using other methods. Also discussed are the possibilities of studying certain geophysical processes, e.g., erosion, weathering, tectonic events based on studies of certain cosmic ray-produced isotopes for the past several million years.

  4. Evidence for the Superbubble Origin of Galactic Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Binns, W.

    2012-12-01

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

  5. 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.

  6. International Cosmic Ray Conference, 17th, Paris, France, July 13-25, 1981, Conference Papers. Volume 2

    NASA Astrophysics Data System (ADS)

    Topics discussed include gamma ray line emission from the galactic plane, cosmic-ray elemental and isotopic compositions, the spectra, composition, and anisotropies of cosmic rays above 1000 GeV, and the analysis of galactic cosmic-ray propagation models. Particular attention is given to the characteristics of low-energy galactic cosmic-rays in interstellar space, cosmic ray sources and acceleration, and observations of secular variations and cosmogenic nuclei. Consideration is also given to nucleosynthesis of light and by-passed isotopes in the solar system matter, fluctuations in the cosmic microwave background, and the magnetic monopole pair and its observation in cosmic rays.

  7. 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.

  8. Cosmic rays: Space Weather Perspective

    NASA Astrophysics Data System (ADS)

    Agarwal Mishra, Rekha; Mishra, Rajesh Kumar

    The concept of Space Weather was launched before a decade to describe the short-term variations in the different form of solar ac-tivity and their effect in the near Earth environ-ment. Space weather affects the Earth's atmos-phere in many ways and through various phe-nomena. Among them, geomagnetic storms and the variability of the galactic cosmic ray flux be-long to the most important ones as for the lower atmosphere. We have performed superposed ep-och analysis using hourly neutron monitor data for three different neutron-monitoring stations of different cut off rigidity as a measure of cosmic ray intensity. In the present study for superposed epoch analysis the time of occurrence of CMEs are defined as key time (zero or epoch hour/day). It is noteworthy that the use of cosmic ray data in space weather research plays a key role for its prediction. We have studied the cosmic ray, geo-magnetic and interplanetary plasma/field data to understand the physical mechanism responsible for Forbush decrease and geomagnetic storm that can be used as a signature to forecast space weather. Keywords: Space weather, cosmic ray, geomag-netic storm, forbush decrease

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. People Interview: Cosmic rays uncover universe theories

    NASA Astrophysics Data System (ADS)

    2012-07-01

    INTERVIEW Cosmic rays uncover universe theories David Smith talks to Paula Chadwick about why she is fascinated by cosmic and gamma rays, and how this is the year that their profile is going to be raised

  19. The Heliosphere and Galactic Cosmic Rays

    NASA Image and Video Library

    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...

  20. 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.; hide

    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.

  1. 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.

  2. Cosmology, Relativity and Cosmic Rays

    NASA Astrophysics Data System (ADS)

    López, Rebeca; Martínez, Humberto; Zepeda, Arnulfo

    2009-04-01

    This is a short review of the evolution of ideas and concepts about the Universe. It is based on the introductory talk given on the 25 of July 2008 within the Third School on Cosmic Rays and Astrophysics held in Arequipa, Peru.

  3. Cosmic-Ray Detectors With Interdigitated Electrodes

    NASA Technical Reports Server (NTRS)

    Cunningham, Thomas J.; Mazed, Mohammed; Holtzman, Melinda J.; Fossum, Eric R.

    1995-01-01

    Detectors measure both positions of incidence and energies of incident charged particles. Stack of detector wafers intercept cosmic ray. Measure positions of incidence to determine cosmic-ray trajectory and charge generated within them (proportional to cosmic-ray energy dissipated within them). Interdigital electrode pattern repeated over many rows and columns on tops of detector wafers in stack. Electrode pattern defines pixels within which points of incidence of incident cosmic rays located.

  4. Implications of new measurements of O-16 + p + C-12,13, N-14,15 for the abundances of C, N isotopes at the cosmic ray source

    NASA Technical Reports Server (NTRS)

    Guzik, T. G.; Wefel, J. P.; Crawford, H. J.; Greiner, D. E.; Lindstrom, P. J.; Schimmerling, W.; Symons, T. J. M.

    1985-01-01

    The fragmentation of a 225 MeV/n O-16 beam was investigated at the Bevalac. Preliminary cross sections for mass = 13, 14, 15 fragments are used to constrain the nuclear excitation functions employed in galactic propagation calculations. Comparison to cosmic ray isotonic data at low energies shows that in the cosmic ray source C-13/C approximately 2% and N-14/0=3-6%. No source abundance of N-15 is required with the current experimental results.

  5. 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.

  6. 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

  7. About cosmic gamma ray lines

    NASA Astrophysics Data System (ADS)

    Diehl, Roland

    2017-06-01

    Gamma ray lines from cosmic sources convey the action of nuclear reactions in cosmic sites and their impacts on astrophysical objects. Gamma rays at characteristic energies result from nuclear transitions following radioactive decays or high-energy collisions with excitation of nuclei. The gamma-ray line from the annihilation of positrons at 511 keV falls into the same energy window, although of different origin. We present here the concepts of cosmic gamma ray spectrometry and the corresponding instruments and missions, followed by a discussion of recent results and the challenges and open issues for the future. Among the lessons learned are the diffuse radioactive afterglow of massive-star nucleosynthesis in 26Al and 60Fe gamma rays, which is now being exploited towards the cycle of matter driven by massive stars and their supernovae; large interstellar cavities and superbubbles have been recognised to be of key importance here. Also, constraints on the complex processes making stars explode as either thermonuclear or core-collapse supernovae are being illuminated by gamma-ray lines, in this case from shortlived radioactivities from 56Ni and 44Ti decays. In particular, the three-dimensionality and asphericities that have recently been recognised as important are enlightened in different ways through such gamma-ray line spectroscopy. Finally, the distribution of positron annihilation gamma ray emission with its puzzling bulge-dominated intensity disctribution is measured through spatially-resolved spectra, which indicate that annihilation conditions may differ in different parts of our Galaxy. But it is now understood that a variety of sources may feed positrons into the interstellar medium, and their characteristics largely get lost during slowing down and propagation of positrons before annihilation; a recent microquasar flare was caught as an opportunity to see positrons annihilate at a source.

  8. Propagation of Secondary Antiprotons and Cosmic Rays in the Galaxy

    NASA Technical Reports Server (NTRS)

    Moskalenko, I. V.; Strong, A. W.; Mashnik, S. G.; Ormes, J. F.; Jones, F. C.

    2002-01-01

    Recent more accurate antiproton data obtained by the BESS team during the last solar minimum pose a challenge to conventional propagation models of cosmic rays. In particular, the diffusive reacceleration model, which matches well key secondary/primary isotope ratios in cosmic rays, fails to reproduce the secondary antiproton spectrum. Tuning both secondary/primary isotope ratios and antiprotons is possible, but requires artificial breaks in the diffusion coefficient and the injection spectrum of primaries. We will discuss some possibilities to overcome these difficulties in the propagation models. We will present new results of our calculation of CR propagation in the Galaxy using the GALPROP code.

  9. Cosmic Ray Observatories for Space Weather Studies.

    NASA Astrophysics Data System (ADS)

    González, Xavier

    2016-07-01

    The Mexican Space Weather Service (SCiESMEX) was created in October 2014. Some observatories measure data for the service at different frequencies and particles. Two cosmic ray observatories detect the particle variations attributed to solar emissions, and are an important source of information for the SCiESMEX. The Mexico City Cosmic Ray Observatory consists of a neutron monitor (6-NM-64) and a muon telescope, that detect the hadronic and hard component of the secondary cosmic rays in the atmosphere. It has been in continous operation since 1990. The Sierra Negra Cosmic Ray Observatory consists of a solar neutron telescope and the scintillator cosmic ray telescope. These telescopes can detect the neutrons, generated in solar flares and the hadronic and hard components of the secondary cosmic rays. It has been in continous operation since 2004. We present the two observatories and the capability to detect variations in the cosmic rays, generated by the emissions of the solar activity.

  10. Nuclear Physics in Space: What We Can Learn From Cosmic Rays

    NASA Technical Reports Server (NTRS)

    Moskalenko, Igor V.

    2004-01-01

    Studies and discoveries in cosmic-ray physics and generally in Astrophysics provide a fertile ground for research in many areas of Particle Physics and Cosmology, such as the search for dark matter, antimatter, new particles, and exotic physics, studies of the nucleosynthesis, origin of Galactic and extragalactic gamma-ray diffuse emission, formation of the large scale structure of the universe etc. In several years new missions are planned for cosmic-ray experiments, which will tremendously increase the quality and accuracy of cosmic-ray data. On the other hand, direct measurements of cosmic rays are possible in only one location on the outskirts of the Milky Way galaxy and present only a snapshot of very dynamic processes. It has been recently realized that direct information about the fluxes and spectra of cosmic rays in distant locations is provided by the Galactic diffuse gamma-rays, therefore, complementing the local cosmic-ray studies. A wealth of information is also contained in the isotopic abundances of cosmic rays, therefore, accurate evaluation of the isotopic production cross sections is of primary importance for Astrophysics of cosmic rays, studies of the galactic chemical evolution, and Cosmology. In this talk, I will show new results obtained with GALPROP, the most advanced numerical model for cosmic-ray propagation, which includes in a self-consistent way all cosmic-ray species (stable and long-lived radioactive isotopes from H to Ni, antiprotons, positrons and electrons, gamma rays and synchrotron radiation), and all relevant processes and reactions.

  11. Nuclear Physics in Space: What We Can Learn From Cosmic Rays

    NASA Technical Reports Server (NTRS)

    Moskalenko, Igor V.

    2004-01-01

    Studies and discoveries in cosmic-ray physics and generally in Astrophysics provide a fertile ground for research in many areas of Particle Physics and Cosmology, such as the search for dark matter, antimatter, new particles, and exotic physics, studies of the nucleosynthesis, origin of Galactic and extragalactic gamma-ray diffuse emission, formation of the large scale structure of the universe etc. In several years new missions are planned for cosmic-ray experiments, which will tremendously increase the quality and accuracy of cosmic-ray data. On the other hand, direct measurements of cosmic rays are possible in only one location on the outskirts of the Milky Way galaxy and present only a snapshot of very dynamic processes. It has been recently realized that direct information about the fluxes and spectra of cosmic rays in distant locations is provided by the Galactic diffuse gamma-rays, therefore, complementing the local cosmic-ray studies. A wealth of information is also contained in the isotopic abundances of cosmic rays, therefore, accurate evaluation of the isotopic production cross sections is of primary importance for Astrophysics of cosmic rays, studies of the galactic chemical evolution, and Cosmology. In this talk, I will show new results obtained with GALPROP, the most advanced numerical model for cosmic-ray propagation, which includes in a self-consistent way all cosmic-ray species (stable and long-lived radioactive isotopes from H to Ni, antiprotons, positrons and electrons, gamma rays and synchrotron radiation), and all relevant processes and reactions.

  12. Characterising CCDs with cosmic rays

    DOE PAGES

    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

  13. 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.

  14. Distributed reacceleration of cosmic rays

    NASA Technical Reports Server (NTRS)

    Wandel, Amri; Eichler, David; Letaw, John R.; Silberberg, Rein; Tsao, C. H.

    1985-01-01

    A model is developed in which cosmic rays, in addition to their initial acceleration by a strong shock, are continuously reaccelerated while propagating through the Galaxy. The equations describing this acceleration scheme are solved analytically and numerically. Solutions for the spectra of primary and secondary cosmic rays are given in a closed analytic form, allowing a rapid search in parameter space for viable propagation models with distributed reeacceleration included. The observed boron-to-carbon ratio can be reproduced by the reacceleration theory over a range of escape parameters, some of them quite different from the standard leaky-box model. It is also shown that even a very modest amount of reacceleration by strong shocks causes the boron-to-carbon ratio to level off at sufficiently high energies.

  15. Cosmic Ray research in Armenia

    NASA Astrophysics Data System (ADS)

    Chilingarian, A.; Mirzoyan, R.; Zazyan, M.

    2009-11-01

    Cosmic Ray research on Mt. Aragats began in 1934 with the measurements of East-West anisotropy by the group from Leningrad Physics-Technical Institute and Norair Kocharian from Yerevan State University. Stimulated by the results of their experiments in 1942 Artem and Abraham Alikhanyan brothers organized a scientific expedition to Aragats. Since that time physicists were studying Cosmic Ray fluxes on Mt. Aragats with various particle detectors: mass spectrometers, calorimeters, transition radiation detectors, and huge particle detector arrays detecting protons and nuclei accelerated in most violent explosions in Galaxy. Latest activities at Mt. Aragats include Space Weather research with networks of particle detectors located in Armenia and abroad, and detectors of Space Education center in Yerevan.

  16. Cosmic Ray Energetics And Mass

    NASA Astrophysics Data System (ADS)

    Seo, Eun-Suk

    2014-08-01

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

  17. The isotopic composition of cosmic rays with 5 is less than or equal to z which is less than or equal to 26

    NASA Technical Reports Server (NTRS)

    Fisher, A. J.; Hagan, F. A.; Maehl, R. C.; Ormes, J. F.; Arens, J. F.

    1975-01-01

    Results obtained from a high altitude balloon flight from Thompson, Canada in August, 1973 are reported. The instrument consisted of a spark chamber, a Lucite Gerenkov counter and thirteen layers of scintillators. For heavy particles the Cerenkov-range method of analysis was used to determine the mass of particles energetic enough to produce a Cerenkov signal and then stop in the layered scintillators. The data appear to be consistent with current cosmic-ray propagation models. Using a simple exponential path length propagation model this data is extrapolated to the cosmic-ray source and some implications of the data are discussed as to the nature of the source.

  18. Cosmic Rays Help Drive Galactic Winds

    NASA Astrophysics Data System (ADS)

    Everett, John; Zweibel, Ellen; Schiller, Quintin; Hu, Kaiqi

    Cosmic rays deposit both momentum and energy into thermal gas when magnetic fields are present (Wentzel, 1968; Kulsrud Pearce, 1969). Since we observe evidence of magnetic fields, cosmic-rays, and hot gas in galactic disks, it is plausible that cosmic rays may add momentum and energy to gas, and therefore help drive galactic-scale outflows. Building on past work by Breitschwerdt, Zirakashvili, Ptuskin, and others, our group investigates "hybrid" galactic winds driven by cosmic-ray and thermal-gas pressure. We have found that such a wind can fit mid-latitude Galactic X-ray emission observed by ROSAT towards the center of the Galaxy, and also (with some physically motivated modifications) fits radio-synchrotron survey data. We are now building estimates of the gamma-ray emission for this wind. So far, we also find that the parameters of such a wind are plausible for the conditions of the central Milky Way. More generally, we illustrate how cosmic-ray driving may increase the prevalance of galactic winds. For this talk, I will review the hydrodynamics of cosmic rays, including the work of other groups on cosmic-ray driven winds. I will highlight how cosmic ray pressure can help drive Galactic winds, how such a wind may work in our Galaxy, and include estimates of the impact of cosmic-ray diffusivity and the driving of cool clouds (observed within extragalactic winds and important to constrain wind velocities) within such a wind.

  19. 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.

  20. The University of California Iron Isotope Experiment. [cosmic ray nuclear resolution using balloon-borne particle telescope

    NASA Technical Reports Server (NTRS)

    Ahlen, S. P.; Cartwright, B. G.; Crawford, H.; Price, P. B.; Tarle, G.

    1975-01-01

    We suggest a novel technique for resolving neighboring isotopes of iron-group nuclei with abundance ratios as great as 20:1 over the energy range from about 360 to about 550 MeV/nucleon. The determination of mass is based on the proportionality between mass and range and the negligible magnitude of range straggling. A balloon-borne experiment based on this technique is described which uses active electronic counters to measure particle speed, trajectory, and charge, and a passive polycarbonate plastic stack to measure range.

  1. Cosmic-ray exposure ages of chondrules

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

    If chondrules were exposed to cosmic rays prior to meteorite compaction, they should retain an excess of cosmogenic noble gases. Beyersdorf-Kuis et al. (2015) 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.

  2. Galactic cosmic ray composition and energy spectra

    NASA Technical Reports Server (NTRS)

    Mewaldt, R. A.

    1994-01-01

    Galactic cosmic ray nuclei represent a significant risk to long-duration spaceflight outside the magnetosphere. We review briefly existing measurements of the composition and energy spectra of heavy cosmic ray nuclei, pointing out which species and energy ranges are most critical to assessing cosmic ray risks for spaceflight. Key data sets are identified and a table of cosmic ray abundances is presented for elements from H to Ni (Z = 1 to 28). Because of the 22-year nature of the solar modulation cycle, data from the approaching 1998 solar minimum is especially important to reducing uncertainties in the cosmic ray radiation hazard. It is recommended that efforts to model this hazard take advantage of approaches that have been developed to model the astrophysical aspects of cosmic rays.

  3. International Cosmic Ray Conference, 13th, University of Denver, Denver, Colo., August 17-30, 1973, Proceedings. Volume 5

    NASA Technical Reports Server (NTRS)

    1974-01-01

    An X-ray observation of the Norma-Lupus region, charge and isotope measurements of heavy cosmic ray nuclei and their role in the determination of cosmic ray age, and the possibility of a contribution to primary cosmic ray spectra from pulsars are among the topics covered in papers concerned with some of the results of recent cosmic ray research. Other topics covered include multiple scattering of charged particles in magnetic fields, absorption of primary cosmic rays in the atmosphere, and phase lag effects on cosmic ray modulation during a recent solar cycle. Individual items are announced in this issue.

  4. International Cosmic Ray Conference, 13th, University of Denver, Denver, Colo., August 17-30, 1973, Proceedings. Volume 5

    NASA Technical Reports Server (NTRS)

    1974-01-01

    An X-ray observation of the Norma-Lupus region, charge and isotope measurements of heavy cosmic ray nuclei and their role in the determination of cosmic ray age, and the possibility of a contribution to primary cosmic ray spectra from pulsars are among the topics covered in papers concerned with some of the results of recent cosmic ray research. Other topics covered include multiple scattering of charged particles in magnetic fields, absorption of primary cosmic rays in the atmosphere, and phase lag effects on cosmic ray modulation during a recent solar cycle. Individual items are announced in this issue.

  5. Underground measurements on secondary cosmic rays

    NASA Technical Reports Server (NTRS)

    Wilson, C. W.; Fenton, A. G.; Fenton, K. B.

    1985-01-01

    Measurements made at the Poatina cosmic ray station (41.8 S 149.9 E, 347 m.w.e.) from August 1983 to July 1984 are summarized. The cosmic ray primary particles responsible for events detected at the station have a median primary energy of 1.2 TeV. The motivation for part of this work came from the reported detection of narrow angle anisotropies in the arrival direction of cosmic rays.

  6. 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.

  7. The Cosmic Ray Leptons Puzzle

    NASA Astrophysics Data System (ADS)

    Brun, P.; Bertone, G.; Cirelli, M.; Moulin, E.

    2009-11-01

    Recent measurements of cosmic ray electrons and positrons by PAMELA, ATIC, Fermi and HESS have revealed interesting excesses and features in the GeV-TeV range. Many possible explanations have been suggested, invoking one or more nearby primary sources such as pulsars and supernova remnants, or dark matter. Based on the output of the TANGO in PARIS --Testing Astroparticle with the New GeV/TeV Observations in Positrons And electRons : Identifying the Sources-- workshop held in Paris in May 2009, we review here the latest experimental results and we discuss some virtues and drawbacks of the many theoretical interpretations proposed so far.

  8. 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.

  9. Cosmic ray modulation and the heliosphere

    NASA Astrophysics Data System (ADS)

    Exarhos, G.; Moussas, X.

    2001-08-01

    We reproduce the long term temporal variations of galactic cosmic ray intensity applying a semi-empirical 1-D diffusion-convection model. We use a shell-like model in which each magnetized shell modulates the cosmic ray intensity during its travel from the Sun to the heliospheric boundary. The cosmic ray intensity at the Earth's orbit is the result of the successive dynamic influence of all shells between the Earth and the heliospheric boundary. Our results are in very good agreement with ground-based observations from Climax and Huancayo cosmic ray stations.

  10. A Journey Through Researches on Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Bhattacharya, R.; Roy, M.; Barman, P.; Mukherjee, C. D.

    2013-04-01

    Cosmic ray causes hazards to microelectronic circuits. Presence of charged particles in the atmosphere was first noticed by Coloumb in 1785. But cosmic ray was discovered by Victor Hess in 1912. However new era of particle physics was started with the invention of neutron monitor in 1948 by John A. Simpson. New information regarding the energy spectrum, anisotropy, latitudinal, longitudinal and daily variation of cosmic ray has added the scientific yield one by one from the analysis of the data of different monitors over the globe. This paper is a brief account of the striking events of cosmic ray which may be the background of future researchers.

  11. Cosmic X-ray physics

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    A progress report of research activities carried out in the area of cosmic X-ray physics is presented. The Diffuse X-ray Spectrometer DXS which has been flown twice as a rocket payload is described. The observation times proved to be too small for meaningful X-ray data to be obtained. Data collection and reduction activities from the Ultra-Soft X-ray background (UXT) instrument are described. UXT consists of three mechanically-collimated X-ray gas proportional counters with window/filter combinations which allow measurements in three energy bands, Be (80-110 eV), B (90-187 eV), and O (e84-532 eV). The Be band measurements provide an important constraint on local absorption of X-rays from the hot component of the local interstellar medium. Work has also continued on the development of a calorimetric detector for high-resolution spectroscopy in the 0.1 keV - 8keV energy range.

  12. 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.

  13. 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.

  14. 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.

  15. Solar Modulation of Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Potgieter, Marius S.

    2013-06-01

    This is an overview of the solar modulation of cosmic rays in the heliosphere. It is a broad topic with numerous intriguing aspects so that a research framework has to be chosen to concentrate on. The review focuses on the basic paradigms and departure points without presenting advanced theoretical or observational details for which there exists a large number of comprehensive reviews. Instead, emphasis is placed on numerical modeling which has played an increasingly significant role as computational resources have become more abundant. A main theme is the progress that has been made over the years. The emphasis is on the global features of CR modulation and on the causes of the observed 11-year and 22-year cycles and charge-sign dependent modulation. Illustrative examples of some of the theoretical and observational milestones are presented, without attempting to review all details or every contribution made in this field of research. Controversial aspects are discussed where appropriate, with accompanying challenges and future prospects. The year 2012 was the centennial celebration of the discovery of cosmic rays so that several general reviews were dedicated to historical aspects so that such developments are briefly presented only in a few cases.

  16. 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.

  17. Cosmic ray composition investigations using ICE/ISEE-3

    NASA Technical Reports Server (NTRS)

    Wiedenbeck, Mark E.

    1992-01-01

    The analysis of data from the high energy cosmic experiment on ISEE-3 and associated modeling and interpretation activities are discussed. The ISEE-3 payload included two instruments capable of measuring the composition of heavy cosmic rays. The designs of these two instruments incorporated innovations which made it possible, for the first time, to measure isotopic as well as the chemical composition for a wide range of elements. As the result of the demonstrations by these two instruments of the capability to resolve individual cosmic ray isotopes, a new generation of detectors was developed using very similar designs, but having improved reliability and increased sensitive area. The composition measurements which were obtained from the ISEE-3 experiment are summarized.

  18. 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

  19. Cosmic rays in star-forming galaxies

    NASA Astrophysics Data System (ADS)

    Porter, Troy

    2013-02-01

    Cosmic rays fill up the entire volume of galaxies, providing an important source of heating and ionization of the interstellar medium, and may play a significant role in the regulation of star formation and evolution of galaxies. Diffuse emissions from radio to highenergy gamma rays (< 100 MeV) arising from various interactions between cosmic rays and the interstellar medium, interstellar radiation field, and magnetic field, are currently the best way to trace the intensities and spectra of cosmic rays in the Milky Way and other galaxies. In this talk, I will give an overview of the observations of the cosmic-ray induced emissions from our own and other galaxies, in particular, results from the Fermi-LAT and Imaging Air Cerenkov telescopes. I will also talk about what can be deduced about the cosmic-ray origin and propagation from these observations.

  20. 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.

  1. Nonresonant Alfven waves driven by cosmic rays

    SciTech Connect

    Melrose, Don

    2005-08-01

    Nonresonant growth of Alfven waves due to streaming cosmic rays is considered, emphasizing the relation between resonant and nonresonant growth and the polarization of the growing waves. The suggested application of this mechanism to the scattering of higher energy cosmic rays in diffusive shock acceleration is discussed critically.

  2. Cosmic-ray detectors on the Moon

    NASA Technical Reports Server (NTRS)

    Linsley, John

    1988-01-01

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

  3. Progress in Astrophysics of Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Moskalenko, Igor

    2017-01-01

    I will review recent progress in Astrophysics of Cosmic Rays and new challenges. I will discuss measurements that have to be done to address these challenges and to further advance our understanding of the phenomenon of cosmic rays, mechanisms of their acceleration and interactions with interstellar medium. Partial support from NASA Grant No. NNX13AC47G is greatly acknowledged.

  4. History of cosmic ray research in Finland

    NASA Astrophysics Data System (ADS)

    Usoskin, I. G.; Valtonen, E.; Vainio, R.; Tanskanen, P. J.; Aurela, A. M.

    2009-11-01

    The history of cosmic ray research in Finland can be traced back to the end of 1950s, when first ground-based cosmic ray measurements started in Turku. The first cosmic ray station was founded in Oulu in 1964 performing measurements of cosmic rays by a muon telescope, which was later complemented by a neutron monitor. Since the 1990s, several research centers and universities, such as The Finnish Meteorological Institute, Helsinki University of Technology, University of Oulu, University of Turku and University of Helsinki have been involved in space science projects, such as SOHO, AMS, Cluster, Cassini, BepiColombo, etc. At the same time, ground-based cosmic ray measurements have reached a new level, including a fully automatic on-line database in Oulu and a new muon measuring underground site in Pyhäsalmi. Research groups in Helsinki, Oulu and Turku have also extensive experience in theoretical investigations of different aspects of cosmic ray physics. Cosmic ray research has a 50-year long history in Finland, covering a wide range from basic long-running ground-based observations to high-technology space-borne instrumentation and sophisticated theoretical studies. Several generations of researchers have been involved in the study ensuring transfer of experience and building the recognized Finnish research school of cosmic ray studies.

  5. 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.

  6. 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.

  7. Cosmic Ray Removal in Fiber Spectroscopic Image

    NASA Astrophysics Data System (ADS)

    Bai, Zhongrui; Zhang, Haotong; Yuan, Hailong; Carlin, Jeffrey L.; Li, Guangwei; Lei, Yajuan; Dong, Yiqiao; Yang, Huiqin; Zhao, Yongheng; Cao, Zihuang

    2017-02-01

    Single-exposure spectra in large spectral surveys are valuable for time domain studies such as stellar variability, but there is no available method to eliminate cosmic rays for single-exposure, multi-fiber spectral images. In this paper, we describe a new method to detect and remove cosmic rays in multi-fiber spectroscopic single exposures. Through the use of two-dimensional profile fitting and a noise model that considers the position-dependent errors, we successfully detect as many as 80% of the cosmic rays and correct the cosmic ray polluted pixels to an average accuracy of 97.8%. Multiple tests and comparisons with both simulated data and real LAMOST data show that the method works properly in detection rate, false detection rate, and validity of cosmic ray correction.

  8. Investigation of Reacceleration on Cosmic Ray

    NASA Astrophysics Data System (ADS)

    Lu, Yuxi; Picot-Clemente, Nicolas; Seo, Eun-Suk

    2016-03-01

    Cosmic rays are high energy charged particles, originating from outer space, that travel at nearly the speed of light and strike the Earth from all directions. One century after the discovery of cosmic rays, their origin and propagation processes remain obscure. GALPROP is a numerical code for calculating the propagation of relativistic charged particles and the diffuse emissions produced during their propagation in the Galaxy. I performed a preliminary study using two different propagation models with the GALPROP code in order to reproduce latest cosmic-ray nuclei measurements. I analyzed multiple propagation parameters for each model, studied their effect on cosmic-ray spectra, optimized and tried a preliminary modification of the code to fit cosmic-ray data such as BESS-Polar, AMS, CREAM, etc.

  9. 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.

  10. Shielding against galactic cosmic rays

    NASA Technical Reports Server (NTRS)

    Schimmerling, W.; Wilson, J. W.; Nealy, J. E.; Thibeault, S. A.; Cucinotta, F. A.; Shinn, J. L.; Kim, M.; Kiefer, R.

    1996-01-01

    Ions of galactic origin are modified but not attenuated by the presence of shielding materials. Indeed, the number of particles and the absorbed energy behind most shield materials increases as a function of shield thickness. The modification of the galactic cosmic ray composition upon interaction with shielding is the only effective means of providing astronaut protection. This modification is intimately conntected with the shield transport porperties and is a strong function of shield composition. The systematic behavior of the shield properites in terms of microscopic energy absorption events will be discussed. The shield effectiveness is examined with respect to convectional protection practice and in terms of a biological endpoint: the efficiency for reduction of the probability of transformation of shielded C3H1OT1/2 mouse cells. The relative advantage of developing new shielding technologies is discussed in terms of a shield performance as related to biological effect and the resulting uncertainty in estimating astronaut risk.

  11. 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.

  12. A Cerenkov-delta E-Cerenkov detector for high energy cosmic ray isotopes and an accelerator study of Ar-40 and Fe-56 fragmentation. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Lau, K. H.

    1985-01-01

    A high energy cosmic ray detector--the High Energy Isotope Spectrometer Telescope (HEIST) is described. It is a large area (0.25 m(swp 2) SR) balloon borne isotope spectrometer designed to make high resolution measurements of isotopes in the element range from neon to nickel (10 Z 28) at energies of about 2 GeV/nucleon. HEIST determines the mass of individual nuclei by measuring both the change in the Lorentz factor (delta gamma) that results from traversing the NaI stack, and the energy loss (delta E) in the stack. Since the total energy of an isotope is given by E = (gamma M), the mass M can be determined by M = delta E/delta, gamma. The instrument is designed to achieve a typical mass resolution of 0.2 amu. The isotopic composition of the fragments from the breakup of high energy An-40 and Fe-56 nuclei are measured experimentally. Isotope yields are compared with calculated yields based on semi-empirical cross-section formulae.

  13. 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.

  14. Opportunities in cosmic-ray physics and astrophysics

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The Board on Physics and Astronomy of the National Research Council established the Committee on Cosmic-Ray Physics to prepare a review of the field that addresses both experimental and theoretical aspects of the origin of cosmic radiation from outside the heliosphere. The following recommendations are made: NASA should provide the opportunity to measure cosmic-ray electrons, positrons, ultraheavy nuclei, isotopes, and antiparticles in space; NASA, the National Science Foundation (NSF), and the Department of Energy (DOE) should facilitate direct and indirect measurement of the elemental composition to as high an energy as possible, for which the support of long-duration ballooning and hybrid ground arrays will be needed; NSF and DOE should support the new Fly's Eye and provide for U.S. participation in the big projects on the horizon, which include giant arrays, ground-based gamma-ray astronomy, and neutrino telescopes; and NASA, NSF, and DOE should support a strong program of relevant theoretical investigations.

  15. 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.

  16. 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.

  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. 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. Cosmic ray transport in astrophysical plasmas

    SciTech Connect

    Schlickeiser, R.

    2015-09-15

    Since the development of satellite space technology about 50 years ago the solar heliosphere is explored almost routinely by several spacecrafts carrying detectors for measuring the properties of the interplanetary medium including energetic charged particles (cosmic rays), solar wind particle densities, and electromagnetic fields. In 2012, the Voyager 1 spacecraft has even left what could be described as the heliospheric modulation region, as indicated by the sudden disappearance of low energy heliospheric cosmic ray particles. With the available in-situ measurements of interplanetary turbulent electromagnetic fields and of the momentum spectra of different cosmic ray species in different interplanetary environments, the heliosphere is the best cosmic laboratory to test our understanding of the transport and acceleration of cosmic rays in space plasmas. I review both the historical development and the current state of various cosmic ray transport equations. Similarities and differences to transport theories for terrestrial fusion plasmas are highlighted. Any progress in cosmic ray transport requires a detailed understanding of the electromagnetic turbulence that is responsible for the scattering and acceleration of these particles.

  20. Electron capture decay of cosmic rays: A model of the inhomogeneous interstellar medium

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    Traditional analyses of cosmic ray composition seek to identify the sources through a determination of a the isotopic abundances of these nuclei prior to acceleration. At the same time, it is both necessary and interesting to understand the nature of the medium through which cosmic rays pass before arriving at detectors. In fact, only within a model of the interstellar medium (ISM) sampled by cosmic rays can a refined estimate of source composition be made. An elaboration of the traditional model of the ISM used in studying cosmic ray propagation is explored. Inhomogeneity of the ISM is accomodated in this model. Within this model it is found that the abundances of some electron apture isotopes, are very sensitive to density inhomogeneities which might be expected in the ISM. These nuclei therefore measure the penetration of heavy cosmic rays into interstellar clouds.

  1. Cosmic ray measurements of light and medium nuclei using a new telescope

    NASA Technical Reports Server (NTRS)

    Preszler, A. M.; Kish, J. C.; Lezniak, J. A.; Simpson, G.; Webber, W. R.

    1975-01-01

    Three separate balloon flights provided with a new multielement cosmic ray telescope are used to collect data on the isotopic composition of cosmic rays of Z equals 3 to 10 in the energy range 150-450 MeV/nuc. The discussion covers Li, Be, B, C, N, and O. The data on Ne is a new finding that suggests a possible enhancement of Ne-22 in cosmic rays relative to the normally accepted universal abundances. Other data are presented which directly verify the expected geomagnetic cutoff effects on isotopes characterized by different charge-to-mass ratio.

  2. Unveiling the Origin of Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Olinto, Angela V.

    2015-04-01

    The origin of cosmic rays, relativistic particles that range from below GeVs to hundreds of EeVs, is a century old mystery. Extremely energetic phenomena occurring over a wide range of scales, from the Solar System to distant galaxies, are needed to explain the non-thermal particle spectrum that covers over 12 orders of magnitude. Space Missions are the most effective platforms to study the origin and history of these cosmic particles. Current missions probe particle acceleration and propagation in the Solar System and in our Galaxy. This year ISS-CREAM and CALET join AMS in establishing the International Space Station as the most active site for studying the origin of Galactic cosmic rays. These missions will study astrophysical cosmic ray accelerators as well as other possible sources of energetic particles such as dark matter annihilation or decay. In the future, the ISS may also be the site for studying extremely high-energy extragalactic cosmic rays with JEM-EUSO. We review recent results in the quest for unveiling the sources of energetic particles with balloons and space payloads and report on activities of the Cosmic ray Science Interest Group (CosmicSIG) under the Physics of the Cosmos Program Analysis Group (PhysPAG).

  3. 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.

  4. 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.

  5. Heliosphere Changes Affect Cosmic Ray Penetration

    NASA Image and Video Library

    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...

  6. Elemental advances of ultraheavy cosmic rays

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The elemental composition of the cosmic-ray source is different from that which has been generally taken as the composition of the solar system. No general enrichment of products of either r-process or s-process nucleosynthesis accounts for the differences over the entire range of ultraheavy (Z 30) elements; specific determination of nucleosynthetic contributions to the differences depends upon an understanding of the nature of any acceleration fractionation. Comparison between the cosmic-ray source abundances and the abundances of C1 and C2 chondritic meteorites suggests that differences between the cosmic-ray source and the standard (C1) solar system may not be due to acceleration fractionation of the cosmic rays, but rather to a fractionation of the C1 abundances with respect to the interstellar abundances.

  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. 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…

  9. 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…

  10. Gravitation, cosmology, and cosmic-ray physics

    SciTech Connect

    Not Available

    1986-01-01

    Gravitation, cosmology, and cosmic-ray physics are often regarded as subfields of astrophysics, as well as physics, because they are practiced by using physical techniques in an astronomical setting. Recent discoveries and opportunities of each field are discussed in this book. Experimental and theoretical work in gravitation, the current theoretical insight into cosmological questions, and new detectors for cosmic-ray physics are some of the topics covered.

  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. 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.

  13. 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.

  14. Development of the cosmic ray techniques

    NASA Technical Reports Server (NTRS)

    Rossi, B.

    1982-01-01

    It has been found that most advances of cosmic-ray physics have been directly related to the development of observational techniques. The history of observational techniques is discussed, taking into account ionization chambers, refinements applied to ionization chambers to make them suitable for an effective use in the study of cosmic radiation, the Wulf-type electrometer, the electrometer designed by Millikan and Neher, the Geiger-Mueller counter, the experiment of Bothe and Kolhoerster, the coincidence circuit, and a cosmic-ray 'telescope'. Attention is given to a magnetic lens for cosmic rays, a triangular arrangement of Geiger-Mueller counters used to demonstrate the production of a secondary radiation, a stereoscopic cloud-chamber photograph of showers, the cloud-chamber picture which provided the first evidence of the positive electron, and arrangements for studying photon components, mu-mesons, and air showers.

  15. Development of the cosmic ray techniques

    NASA Technical Reports Server (NTRS)

    Rossi, B.

    1982-01-01

    It has been found that most advances of cosmic-ray physics have been directly related to the development of observational techniques. The history of observational techniques is discussed, taking into account ionization chambers, refinements applied to ionization chambers to make them suitable for an effective use in the study of cosmic radiation, the Wulf-type electrometer, the electrometer designed by Millikan and Neher, the Geiger-Mueller counter, the experiment of Bothe and Kolhoerster, the coincidence circuit, and a cosmic-ray 'telescope'. Attention is given to a magnetic lens for cosmic rays, a triangular arrangement of Geiger-Mueller counters used to demonstrate the production of a secondary radiation, a stereoscopic cloud-chamber photograph of showers, the cloud-chamber picture which provided the first evidence of the positive electron, and arrangements for studying photon components, mu-mesons, and air showers.

  16. Development of the cosmic ray techniques

    NASA Astrophysics Data System (ADS)

    Rossi, B.

    1982-12-01

    It has been found that most advances of cosmic-ray physics have been directly related to the development of observational techniques. The history of observational techniques is discussed, taking into account ionization chambers, refinements applied to ionization chambers to make them suitable for an effective use in the study of cosmic radiation, the Wulf-type electrometer, the electrometer designed by Millikan and Neher, the Geiger-Mueller counter, the experiment of Bothe and Kolhoerster, the coincidence circuit, and a cosmic-ray 'telescope'. Attention is given to a magnetic lens for cosmic rays, a triangular arrangement of Geiger-Mueller counters used to demonstrate the production of a secondary radiation, a stereoscopic cloud-chamber photograph of showers, the cloud-chamber picture which provided the first evidence of the positive electron, and arrangements for studying photon components, mu-mesons, and air showers.

  17. TIGER: Progress in Determining the Sources of Galactic Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Israel, Martin

    2009-05-01

    The Trans-Iron Galactic Element Recorder (TIGER) is a 1-square-meter detector system composed of scintillators, Cherenkov detectors, and scintillating optical fibers, which gives excellent resolution of individual elements in the cosmic rays. With two high-altitude balloon flights over Antarctica, TIGER accumulated fifty days of data on the elemental composition of the rare galactic cosmic rays heavier than Ni, measuring the abundances of Cu, Zn, Ga, Ge, Se, and Sr, as well as the more abundant lighter elements. After accounting for fragmentation of cosmic rays as they propagate through the Galaxy and the atmosphere above the detector system, the source material appears to be a mixture of about 80% ``standard'' Solar-System composition and 20% ejecta from massive stars. This mixture supports a model of cosmic-ray origin in OB associations, as has previously been inferred from the isotopic composition of the more abundant elements, Ni and lighter. These TIGER data also support a cosmic-ray acceleration model in which elements present in interstellar grains are accelerated preferentially compared with those found in interstellar gas. This emerging model of cosmic-ray origin and acceleration will be further tested with a similar but much larger instrument that will give much better statistics, improve the precision of TIGER'S studies and allowing more rare elements to be studied; Super-TIGER development is beginning now, leading to its first balloon flight in December 2012. The TIGER investigation is a collaboration among scientists at Washington University in St. Louis, NASA Goddard Space Flight Center, California Institute of Technology, Jet Propulsion Laboratory, and University of Minnesota. Principal funding for this research was from NASA under grant NNG05WC04G. We also acknowledge the excellent work of the staff of the Columbia Scientific Balloon Facility, the NASA Balloon Program Office, and the NSF Office of Polar Programs.

  18. 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. )

  19. Polycyclic aromatic hydrocarbon processing by cosmic rays

    NASA Astrophysics Data System (ADS)

    Micelotta, E. R.; Jones, A. P.; Tielens, A. G. G. M.

    2011-02-01

    Context. Cosmic rays are present in almost all phases of the ISM. Polycyclic aromatic hydrocarbons (PAHs) and cosmic rays represent an abundant and ubiquitous component of the interstellar medium. However, the interaction between them has never before been fully investigated. Aims: To study the effects of cosmic ray ion (H, He, CNO and Fe-Co-Ni) and electron bombardment of PAHs in galactic and extragalactic environments. Methods: We calculate the nuclear and electronic interactions for collisions between PAHs and cosmic ray ions and electrons with energies between 5 MeV/nucleon and 10 GeV, above the threshold for carbon atom loss, in normal galaxies, starburst galaxies and cooling flow galaxy clusters. Results: The timescale for PAH destruction by cosmic ray ions depends on the electronic excitation energy E0 and on the amount of energy available for dissociation. Small PAHs are destroyed faster, with He and the CNO group being the more effective projectiles. For electron collisions, the lifetime is independent of the PAH size and varies with the threshold energy T0. Conclusions: Cosmic rays process the PAHs in diffuse clouds, where the destruction due to interstellar shocks is less efficient. In the hot gas filling galactic halos, outflows of starburst galaxies and intra-cluster medium, PAH destruction is dominated by collisions with thermal ions and electrons, but this mechanism is ineffective if the molecules are in denser cloudlets and isolated from the hot gas. Cosmic rays can access the denser clouds and together with X-rays will set the lifetime of those protected PAHs. This limits the use of PAHs as a "dye" for tracing the presence of cold entrained material.

  20. Diffuse Galactic gamma rays from shock-accelerated cosmic rays.

    PubMed

    Dermer, Charles D

    2012-08-31

    A shock-accelerated particle flux is proportional to p(-s), where p is the particle momentum, follows from simple theoretical considerations of cosmic-ray acceleration at nonrelativistic shocks followed by rigidity-dependent escape into the Galactic halo. A flux of shock-accelerated cosmic-ray protons with s≈2.8 provides an adequate fit to the Fermi Large Area Telescope γ-ray emission spectra of high-latitude and molecular cloud gas when uncertainties in nuclear production models are considered. A break in the spectrum of cosmic-ray protons claimed by Neronov, Semikoz, and Taylor [Phys. Rev. Lett. 108, 051105 (2012)] when fitting the γ-ray spectra of high-latitude molecular clouds is a consequence of using a cosmic-ray proton flux described by a power law in kinetic energy.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Cosmic-ray picture of the heliosphere

    NASA Technical Reports Server (NTRS)

    Venkatesan, D.

    1985-01-01

    The existing data base on the characteristics of the heliosphere is discussed. It is known that solar gravity is less than necessary to hold all the solar material, and therefore a supersonic solar wind exists. Skylab soft X-ray photographs revealed the existence of coronal holes, which evolve in an 11 yr cycle. It has been proposed that all but the highest energy cosmic rays detected on earth can be attributed to solar and heliospheric origins, a controversial view which requires further empirical and theoretical work on particle acceleration processes and regions of interaction of the solar wind with interplanetary plasma. It is possible that a warped solar current sheet stretches to interplanetary space and organizes the solar magnetic field and thereby guides cosmic rays. An inverse correlation has been identified between the sunspot cycle and cosmic ray intensity. The features and effects of solar flares, subsequent shock waves and high speed particle streams are also discussed.

  7. Cosmic ray records in Antarctic meteorites

    NASA Technical Reports Server (NTRS)

    Vogt, S.; Herpers, U.; Sarafin, R.; Signer, P.; Wieler, R.; Suter, M.; Woelfli, W.

    1986-01-01

    The cosmogenic radionuclides Be(10), Al(26), and Mn(53) and noble gases were determined in more than 28 meteorites from Antarctica by nuclear analytical techniques and static mass spectrometry, respectively. The summarized results are listed. The concentrations of Al(26) and Mn(53) are normalized to the repective main target elements and given in dpm/kg Si sub eq and dpm/kg Fe. The errors stated include statistical as well as systematical errors. For noble gas concentrations estimated errors are 5% and for isotopic ratios 1.5%. Cosmic ray exposure ages T sub 21 were calculated by the noble gas concentrations and the terrestrial residence time (T) on the basis of the spallogenic nuclide Al(26). The suggested pairing of the LL6 chondrite RKPA 80238 and RKPA 80248 and the eucrites ALHA 76005 and ALHA 79017 is confirmed not only by the noble gas data but also by the concentrations of the spallation produced radionuclides. Futhermore, ALHA 80122, clasified as an H6 chondrite, has a noble gas pattern which suggest that this meteorite belongs to the ALHA 80111 shower.

  8. Space weather prediction by cosmic rays

    NASA Astrophysics Data System (ADS)

    Mavromichalaki, H.; Souvatzoglou, G.; Sarlanis, C.; Mariatos, G.; Plainaki, C.; Gerontidou, M.; Belov, A.; Eroshenko, E.; Yanke, V.

    Relativistic (galactic and solar) cosmic rays (CR) registered by neutron monitors can play a useful key-role in space weather storms forecasting and in the specification of magnetic properties of coronal mass ejections (CMEs), shocks and ground level enhancements (GLEs). In order to produce a real-time prediction of space weather phenomena, only real-time data from a neutron monitor network should be employed. Recently in Athens cosmic-ray station a real-time data collection and acquisition system has been created in collaboration with the cosmic ray group of IZMIRAN. This system collects data in real-time mode from about 15 real-time cosmic ray stations by using the internet. The main server in Athens station collects 5-min and hourly cosmic ray data. The measurements of all stations are being processed automatically while converted into a suitable form, so as to be serviceably for forecasting purposes. All programs have been written in an expandable form, in order to upgrade the network of real-time neutron monitors with the biggest possible number of stations, easily. Programs which make use of these data for forecasting studies are already running in experimental mode. The increased number of NM stations operating in real time provides a good basis for using Neutron Monitor network as a tool of forecasting the arrival of the interplanetary disturbances at the Earth.

  9. 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.

  10. 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}).

  11. 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.

  12. 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.

  13. 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,

  14. A cosmic-ray age based on the abundance of Be-10

    NASA Technical Reports Server (NTRS)

    Wiedenbeck, M. E.; Greiner, D. E.

    1980-01-01

    The paper discusses a measurement of the isotopic composition of galactic cosmic-ray beryllium made with high resolution aboard the ISEE 3 spacecraft. The isotope fractions of Be-7, Be-9, and Be-10 were determined; the abundance of the radioactive isotope Be-10 is used to deduce the cosmic-ray confinement time of 8,400,000/yr and an interstellar gas density of 0.33 atoms/cu cm in the confinement volume. Errors in the propagation model parameters which result in comparable uncertainties are discussed.

  15. 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.

  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. 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.

  19. Galactic Cosmic Rays and the Light Elements

    NASA Astrophysics Data System (ADS)

    Parizot, Etienne

    2001-10-01

    The study of the light elements abundances in low metallicity stars offers a unique way to learn about the past content of our Galaxy in energetic particles (EPs). This study teaches us that either the light elements are not produced by cosmic rays interactions in the interstellar medium (ISM), as has been thought for 30 years, or the cosmic rays are not what one usually thinks they are, namely standard interstellar material accelerated by the shock waves generated by supernova explosions. In any case, we have to revise our understanding of the EPs in the Galaxy. Relying on the observational evidence about Li, Be and B Galactic evolution as well as about the distribution of massive stars, we show that most of the EPs responsible for the production of light elements must be accelerated inside superbubbles, as is probably the case for the standard Galactic cosmic rays as well.

  20. 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.

  1. Cosmic ray antiprotons at high energies

    NASA Astrophysics Data System (ADS)

    Winkler, Martin Wolfgang

    2017-02-01

    Cosmic ray antiprotons provide a powerful tool to probe dark matter annihilations in our galaxy. The sensitivity of this important channel is, however, diluted by sizable uncertainties in the secondary antiproton background. In this work, we improve the calculation of secondary antiproton production with a particular focus on the high energy regime. We employ the most recent collider data and identify a substantial increase of antiproton cross sections with energy. This increase is driven by the violation of Feynman scaling as well as by an enhanced strange hyperon production. The updated antiproton production cross sections are made publicly available for independent use in cosmic ray studies. In addition, we provide the correlation matrix of cross section uncertainties for the AMS-02 experiment. At high energies, the new cross sections improve the compatibility of the AMS-02 data with a pure secondary origin of antiprotons in cosmic rays.

  2. 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.

  3. Ion acceleration to cosmic ray energies

    NASA Technical Reports Server (NTRS)

    Lee, Martin A.

    1990-01-01

    The acceleration and transport environment of the outer heliosphere is described schematically. Acceleration occurs where the divergence of the solar-wind flow is negative, that is at shocks, and where second-order Fermi acceleration is possible in the solar-wind turbulence. Acceleration at the solar-wind termination shock is presented by reviewing the spherically-symmetric calculation of Webb et al. (1985). Reacceleration of galactic cosmic rays at the termination shock is not expected to be important in modifying the cosmic ray spectrum, but acceleration of ions injected at the shock up to energies not greater than 300 MeV/charge is expected to occur and to create the anomalous cosmic ray component. Acceleration of energetic particles by solar wind turbulence is expected to play almost no role in the outer heliosphere. The one exception is the energization of interstellar pickup ions beyond the threshold for acceleration at the quasi-perpendicular termination shock.

  4. Cosmic-ray physics at CERN

    NASA Astrophysics Data System (ADS)

    Rodríguez Cahuantzi, M.

    2017-06-01

    Accelerator experiments located underground are suitable for the study of atmospheric muons. The use of high-energy collider detectors for cosmic-ray physics was pioneered during the era of the Large Electron-Positron (LEP) collider at CERN by ALEPH, DELPHI and L3 collaborations. A development of these programs is possible at the Large Hadron Collider (LHC), where experiments like ALICE and CMS will operate for many years, with the possibility of recording a large amount of cosmic-ray data. In this proceedings, a review of the results obtained by LEP and LHC experiments is presented. This material was discussed along two sessions during the VI School on Cosmic-ray Physics and Astrophysics held at the Mesoamerican Center for Theoretical Physics (MCTP) located in Tuxtla Gutierrez, Chiapas, Mexico.

  5. Underground cosmic-ray experiment EMMA

    NASA Astrophysics Data System (ADS)

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

    2007-03-01

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

  6. Positrons and Antiprotons in Galactic Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Cowsik, R.

    2016-10-01

    I consider the impact of recent measurements of positron and antiproton spectra in cosmic rays on our understanding of the origins and propagation of cosmic rays, as well as on the annihilation and decay characteristics of particles of Galactic dark matter, from the perspective of current models postulating energy-dependent leakage of cosmic rays from the Galaxy and of the nested leaky-box model, in which the leakage from the Galaxy is independent of energy. The nested leaky-box model provides a straightforward and consistent explanation of the observed spectral intensities, and finds no compelling need for a contribution from the annihilation or decay of Galactic dark matter. Improved observations and modeling efforts are needed to probe the properties of dark matter deeply enough to be significant to particle physics and cosmology.

  7. Nuclear Physics Meets the Sources of the Ultra-High Energy Cosmic Rays.

    PubMed

    Boncioli, Denise; Fedynitch, Anatoli; Winter, Walter

    2017-07-07

    The determination of the injection composition of cosmic ray nuclei within astrophysical sources requires sufficiently accurate descriptions of the source physics and the propagation - apart from controlling astrophysical uncertainties. We therefore study the implications of nuclear data and models for cosmic ray astrophysics, which involves the photo-disintegration of nuclei up to iron in astrophysical environments. We demonstrate that the impact of nuclear model uncertainties is potentially larger in environments with non-thermal radiation fields than in the cosmic microwave background. We also study the impact of nuclear models on the nuclear cascade in a gamma-ray burst radiation field, simulated at a level of complexity comparable to the most precise cosmic ray propagation code. We conclude with an isotope chart describing which information is in principle necessary to describe nuclear interactions in cosmic ray sources and propagation.

  8. Monte Carlo Simulations of Cosmic Rays Hadronic Interactions

    SciTech Connect

    Aguayo Navarrete, Estanislao; Orrell, John L.; Kouzes, Richard T.

    2011-04-01

    This document describes the construction and results of the MaCoR software tool, developed to model the hadronic interactions of cosmic rays with different geometries of materials. The ubiquity of cosmic radiation in the environment results in the activation of stable isotopes, referred to as cosmogenic activities. The objective is to use this application in conjunction with a model of the MAJORANA DEMONSTRATOR components, from extraction to deployment, to evaluate cosmogenic activation of such components before and after deployment. The cosmic ray showers include several types of particles with a wide range of energy (MeV to GeV). It is infeasible to compute an exact result with a deterministic algorithm for this problem; Monte Carlo simulations are a more suitable approach to model cosmic ray hadronic interactions. In order to validate the results generated by the application, a test comparing experimental muon flux measurements and those predicted by the application is presented. The experimental and simulated results have a deviation of 3%.

  9. Review of the Second School on Cosmic Rays and Astrophysics

    NASA Astrophysics Data System (ADS)

    Martínez, Humberto

    2009-04-01

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

  10. Cosmic ray-driven winds in the Galactic environment and the cosmic ray spectrum

    NASA Astrophysics Data System (ADS)

    Recchia, S.; Blasi, P.; Morlino, G.

    2017-09-01

    Cosmic rays escaping the Galaxy exert a force on the interstellar medium directed away from the Galactic disc. If this force is larger than the gravitational pull due to the mass embedded in the Galaxy, then galactic winds may be launched. Such outflows may have important implications for the history of star formation of the host galaxy, and in turn affect in a crucial way the transport of cosmic rays, both due to advection with the wind and to the excitation of waves by the same cosmic rays, through streaming instability. The possibility to launch cosmic ray-induced winds and the properties of such winds depend on environmental conditions, such as the density and temperature of the plasma at the base of the wind and the gravitational potential, especially the one contributed by the dark matter halo. In this paper, we make a critical assessment of the possibility to launch cosmic ray-induced winds for a Milky Way-like galaxy and how the properties of the wind depend upon the conditions at the base of the wind. Special attention is devoted to the implications of different conditions for wind launching on the spectrum of cosmic rays observed at different locations in the disc of the galaxy. We also comment on how cosmic ray-induced winds compare with recent observations of Oxygen absorption lines in quasar spectra and emission lines from blank sky, as measured by XMM-Newton/EPIC-MOS.

  11. 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).

  12. 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.

  13. 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.

  14. Cosmic Rays: studies and measurements before 1912

    NASA Astrophysics Data System (ADS)

    De Angelis, Alessandro

    2013-06-01

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

  15. Cosmic Ray Mass Measurements with LOFAR

    NASA Astrophysics Data System (ADS)

    Buitink, Stijn; Bonardi, Antonio; Corstanje, Arthur; Enriquez, J. Emilio; Falcke, Heino; Hörandel, Jörg R.; Mitra, Pragati; Mulrey, Katie; Nelles, Anna; Rachen, Jörg Paul; Rossetto, Laura; Schellart, Pim; Scholten, Olaf; Thoudam, Satyendra; Trinh, Gia; ter Veen, Sander; Winchen, Tobias

    2017-03-01

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

  16. Cosmic-ray Muon Flux In Belgrade

    SciTech Connect

    Banjanac, R.; Dragic, A.; Jokovic, D.; Udovicic, V.; Puzovic, J.; Anicin, I.

    2007-04-23

    Two identical plastic scintillator detectors, of prismatic shape (50x23x5)cm similar to NE102, were used for continuous monitoring of cosmic-ray intensity. Muon {delta}E spectra have been taken at five minute intervals, simultaneously from the detector situated on the ground level and from the second one at the depth of 25 m.w.e in the low-level underground laboratory. Sum of all the spectra for the years 2002-2004 has been used to determine the cosmic-ray muon flux at the ground level and in the underground laboratory.

  17. 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.

  18. Explaining TeV cosmic-ray anisotropies with non-diffusive cosmic-ray propagation

    SciTech Connect

    Harding, James Patrick; Fryer, Chris Lee; Mendel, Susan Marie

    2016-05-11

    Constraining the behavior of cosmic ray data observed at Earth requires a precise understanding of how the cosmic rays propagate in the interstellar medium. The interstellar medium is not homogeneous; although turbulent magnetic fields dominate over large scales, small coherent regions of magnetic field exist on scales relevant to particle propagation in the nearby Galaxy. Guided propagation through a coherent field is significantly different from random particle diffusion and could be the explanation of spatial anisotropies in the observed cosmic rays. We present a Monte Carlo code to propagate cosmic particle through realistic magnetic field structures. We discuss the 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. Furthermore, the features induced by coherent magnetic structure could be the cause of the observed TeV cosmic-ray anisotropy.

  19. Explaining TeV cosmic-ray anisotropies with non-diffusive cosmic-ray propagation

    DOE PAGES

    Harding, James Patrick; Fryer, Chris Lee; Mendel, Susan Marie

    2016-05-11

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

  20. Explaining TeV cosmic-ray anisotropies with non-diffusive cosmic-ray propagation

    SciTech Connect

    Harding, James Patrick; Fryer, Chris Lee; Mendel, Susan Marie

    2016-05-11

    Constraining the behavior of cosmic ray data observed at Earth requires a precise understanding of how the cosmic rays propagate in the interstellar medium. The interstellar medium is not homogeneous; although turbulent magnetic fields dominate over large scales, small coherent regions of magnetic field exist on scales relevant to particle propagation in the nearby Galaxy. Guided propagation through a coherent field is significantly different from random particle diffusion and could be the explanation of spatial anisotropies in the observed cosmic rays. We present a Monte Carlo code to propagate cosmic particle through realistic magnetic field structures. We discuss the 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. Furthermore, the features induced by coherent magnetic structure could be the cause of the observed TeV cosmic-ray anisotropy.

  1. 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.

  2. Cosmic-ray-produced neon and helium in the summit lavas of Maui

    NASA Technical Reports Server (NTRS)

    Marti, K.; Craig, H.

    1987-01-01

    The identification of cosmic-ray-produced Ne-21c in addition to He-3c, components attributed to cosmic ray-induced spallation reactions, are reported in gases extracted by fusion of olivines and clinopyroxenes after vacuum-crushing. The observed (He-3/Ne-21)c ratios and the ratio of Ne-21c in olivine to that in clinopyroxene are consistent with an in situ origin of He-3c and Ne-21c by cosmic-ray spallation reactions. These components could be important for interpreting helium isotopic data in terrestrial reservoirs. Geophysical applications could include determinations of erosion rates and exposure histories of terrestrial rocks.

  3. Cosmic-ray-produced neon and helium in the summit lavas of Maui

    NASA Technical Reports Server (NTRS)

    Marti, K.; Craig, H.

    1987-01-01

    The identification of cosmic-ray-produced Ne-21c in addition to He-3c, components attributed to cosmic ray-induced spallation reactions, are reported in gases extracted by fusion of olivines and clinopyroxenes after vacuum-crushing. The observed (He-3/Ne-21)c ratios and the ratio of Ne-21c in olivine to that in clinopyroxene are consistent with an in situ origin of He-3c and Ne-21c by cosmic-ray spallation reactions. These components could be important for interpreting helium isotopic data in terrestrial reservoirs. Geophysical applications could include determinations of erosion rates and exposure histories of terrestrial rocks.

  4. 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.

  5. 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.

  6. 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.

  7. Post-launch data analysis for the cosmic ray isotope experiment ONR-604 in the Combined Release and Radiation Effects Satellite (CRRES)

    NASA Technical Reports Server (NTRS)

    Simpson, John A.; Garcia-Munoz, Moises

    1995-01-01

    Research was continued on the origins, acceleration mechanisms, and the propagation modes of the hierarchy of energetic charged particles found in a wide range of astrophysical settings, extending from the cosmic rays arriving from the depth of the galaxy to the energetic particles in the heliosphere and in the near earth environment. In particular this grant has been a vital support in the investigation of the particle radiations in the earth's magnetosphere. The ONR-604 instrument was launched in July 1990 aboard the CRRES spacecraft. The CRRES mission has been a joint program of NASA and the U.S. Air Force Space Test Program which has provided launch support and telemetry coverage. The spacecraft was placed into a low-inclination eccentric orbit with a period of approximately 10 hours, and thus measured charged particle fluxes in both interplanetary space and in the earth's trapped radiation. ONR-604 performed extremely well, both in interplanetary space and in the intense radiation belt environment. We were able to make detailed measurements of interplanetary fluxes and composition into L=4, or for more than 50% of the orbital period. Thus the experiment produced two valuable datasets, one set outside of L=4 for interplanetary studies, and one set inside of L=4 for radiation belt studies. The data returned by the University of Chicago ONR-604 instrument has been the base for 10 papers on magnetospheric and galactic energetic-particle research.

  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. Cosmic gamma-rays and cosmic nuclei above 1 TeV

    NASA Technical Reports Server (NTRS)

    Watson, A. A.

    1986-01-01

    Work on cosmic gamma rays and cosmic nuclei above I TeV is described and evaluated. The prospect that gamma ray astronomy above I TeV will give new insights into high energy cosmic ray origin within our galaxy is particularly bright.

  10. An alternative interpretation for cosmic ray peaks

    DOE PAGES

    Kim, Doojin; Park, Jong -Chul

    2015-10-03

    We propose an alternative mechanism based upon dark matter (DM) interpretation for anomalous peak signatures in cosmic ray measurements, assuming an extended dark sector with two DM species. This is contrasted with previous effort to explain various line-like cosmic-ray excesses in the context of DM models where the relevant DM candidate directly annihilates into Standard Model (SM) particles. The heavier DM is assumed to annihilate to an on-shell intermediate state. As the simplest choice, it decays directly into the lighter DM along with an unstable particle which in turn decays to a pair of SM states corresponding to the interestingmore » cosmic anomaly. We show that a sharp continuum energy peak can be readily generated under the proposed DM scenario, depending on dark sector particle mass spectra. Remarkably, such a peak is robustly identified as half the mass of the unstable particle. Furthermore, other underlying mass parameters are analytically related to the shape of energy spectrum. We apply this idea to the two well-known line excesses in the cosmic photon spectrum: 130 GeV γ-ray line and 3.5 keV X-ray line. As a result, each observed peak spectrum is well-reproduced by theoretical expectation predicated upon our suggested mechanism, and moreover, our resulting best fits provide rather improved χ2 values.« less

  11. 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.

  12. Searching for Dark Matter with Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Seo, Eun-Suk

    2015-04-01

    One of the most exciting possibilities in cosmic ray research is the potential to discover new phenomena. A number of elementary particles were discovered in cosmic rays before modern-day accelerators became available to study their detailed properties. Since the discovery of cosmic ray antiprotons in 1979 using a balloon-borne magnet spectrometer, a series of magnet spectrometers have been flown to search for the signature of dark matter annihilation in antiprotons and positrons. Being the same as particles except for their opposite charge sign, antiparticles are readily distinguished as they bend in opposite directions in the magnetic field. As long-duration balloon flights over Antarctica became available, not only antiproton to proton ratios but also measurements of antiproton energy spectra became possible. More recently, space missions are also providing precision measurements of electron and position energy spectra. With other measurements to constrain cosmic ray propagation models, these new measurements play key roles in constraining dark-matter models for understanding the nature of dark matter. Recent results, their implications, and outlook for the field will be presented.

  13. 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

  14. "Anomalous" Galactic Cosmic Rays from Astrospheres

    NASA Astrophysics Data System (ADS)

    Scherer, Klaus; Ferreira, Stefan; Becker, Julia; Bomans, Dominik; Weis, Kerstin

    2012-07-01

    One paradigm concerning galactic cosmic ray energy spectra is that they are created in violent events, like supernova explosions. Recently, we have demonstrated that Sun-like stars can contribute to the lower energy range of the cosmic ray proton spectrum, by creating so-called anomalous cosmic rays (ACRs). The seed population of the latter are the interstellar neutrals, which become ionized inside an astrosphere. The resulting `pick-up ions' are convcted across the astrospherical (stellar wind) termination shock and, because their velocity distribution differs from that of the shocked wind plasma, they will be accelerated to higher energies by shock and stochastic acceleration as well as adiabatic heating. All these acceleration processes depend strongly on the underlying plasma structure. We have developed and refined a selfconsistent hybrid code, i.e. a fluid description of the thermal species and a kinetic one for the energetic particles, and validated it using heliospheric in situ observations. Recently, we have applied our model to the astrospheres of hot stars ("interstellar bubbles"). Here, we will present first results of the production of "anomalous" cosmic rays in the vicinity of interstellar bubbles around hot stars.

  15. 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.

  16. A Cannonball Model of Cosmic Rays

    NASA Astrophysics Data System (ADS)

    de Rújula, A.

    2006-01-01

    I outline a Cannon Ball model of Cosmic Rays in which their distribution in the Galaxy, their total “luminosity”, the broken power-law spectra with their observed slopes, the position of the knee(s) and ankle(s), and the alleged variations of composition with energy are all explained in terms of simple and “standard” physics.

  17. 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.

  18. 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…

  19. Primary cosmic rays on the lunar surface

    NASA Technical Reports Server (NTRS)

    Vernov, S. N.; Lavrukhina, A. K.

    1977-01-01

    Results are reported for determination of the galactic cosmic ray flux during various time intervals in the 1965-1972 period, on the basis of data from the instruments of a spacecraft that made a soft landing on the lunar surface, and from the radioactivity of samples returned by the spacecraft. During minimum solar activity (the second half of 1965 and the beginning of 1966) I sub 0 (E greater than or equal to 30 percent MeV/nucleon) was determined to be 0.43 (plus or minus 10 percent). These values, within the error limits of the determinations, agree with the corresponding values of galactic cosmic ray intensities determined by stratospheric measurements. The mean flux of galactic cosmic rays over the past million years is equal to I (E greater or equal to 100 MeV/nucleon) + 0.28 (plus or minus 20 percent). This value agrees with the mean flux of modulated cosmic rays during the period of the nineteenth solar cycle. The mean flux of solar protons between 1965 and 1972 was 2.46.

  20. 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…

  1. Current Status of Astrophysics of Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Moskalenko, Igor

    2016-03-01

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

  2. High energy interactions of cosmic ray particles

    NASA Technical Reports Server (NTRS)

    Jones, L. W.

    1986-01-01

    The highlights of seven sessions of the Conference dealing with high energy interactions of cosmic rays are discussed. High energy cross section measurements; particle production-models of experiments; nuclei and nuclear matter; nucleus-nucleus collision; searches for magnetic monopoles; and studies of nucleon decay are covered.

  3. New aspects of heavy cosmic rays from calcium to nickel (Z = 20 to 28)

    NASA Technical Reports Server (NTRS)

    Mewaldt, Richard A.; Webber, W. R.

    1990-01-01

    Over the two year course of this grant a study was conducted to explore the implications of composition measurements of heavy cosmic rays made by the Third High Energy Astronomy Observatory (HEAO-3). To interpret these and other measurements this study combined for the first time new laboratory measurements of the fragmentation cross sections of heavy nuclei, a new semi-empirical cross section formula, and the latest in cosmic ray propagation and solar modulation models. These models were used to interpret abundance measurements from six recent satellite experiments, including, in particular, two from HEAO-3. The principal results of the study were: (1) an improved interpretation of the Mn-54 clock in cosmic rays, including predictions of the isotopic abundances of Mn for comparison with future isotope measurements; (2) the first realization of the effect of Mn-54 decay on studies of the source abundances of Fe isotopes; (3) improved source abundances of the elements Ar, Ca, Cr, Mn, Fe, and Ni in the cosmic ray source material; (4) an improved fit to the abundances of Fe secondaries in cosmic rays; and (5) additional evidence that supports the validity of the leaky-box model of cosmic ray propagation in the galaxy. This final report summarizes these new results, the new tools that were developed to obtain them, and presents a bibliography of talks and publications that resulted from this work.

  4. 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.

  5. Heliospheric Impact on Cosmic Rays Modulation

    NASA Astrophysics Data System (ADS)

    Tiwari, Bhupendra Kumar

    2016-07-01

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

  6. Impact of Cosmic Ray Transport on Galactic Winds

    NASA Astrophysics Data System (ADS)

    Farber, Ryan; Ruszkowski, Mateusz; Yang, Hsiang-Yi Karen; Gould Zweibel, Ellen

    2017-08-01

    Despite playing a fundamental role in galaxy evolution, the physical mechanisms responsible for driving galactic winds remain unclear. The role of cosmic rays generated by supernovae and young stars has very recently begun to receive significant attention due to the realization that cosmic rays can efficiently accelerate galactic winds. Microscopic cosmic ray transport processes are fundamental for determining the efficiency of cosmic ray wind driving. Previous studies focused on modeling of cosmic ray transport either via constant diffusion coefficient or via streaming proportional to the Alfv{é}n speed. However, in predominantly neutral gas, cosmic rays can propagate faster than in the ionized medium and the effective transport can be substantially larger, i.e., cosmic rays are decoupled from the gas. We perform three-dimensional magneto-hydrodynamical simulations of patches of galactic disks including the effects of cosmic rays. Our simulations include the decoupling of cosmic rays in the neutral ISM phases. We find that, compared to the ordinary diffusive cosmic ray transport case, accounting for the decoupling leads to significantly different wind properties such as the cosmic ray spatial distribution, wind speed, density, and temperature. These results have implications for the magnetization of the circumgalactic medium and the pollution of the circumgalactic medium with cosmic rays.

  7. 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.

  8. 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.

  9. Cosmic Ray investigations on peak Musala in Bulgaria: A memoir

    NASA Astrophysics Data System (ADS)

    Kavlakov, S.

    2009-11-01

    A very brief historical description of the Bulgarian Cosmic Ray investigations, in the Cosmic Ray Station on peak Musala (2925 m.a.s.l.) is presented. Difficulties of the high mountain measurements that time are mentioned, together with the hard emotional and successful work done by a small staff of young Bulgarian cosmic ray scientists.

  10. 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.

  11. 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.

  12. 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.

  13. 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…

  14. 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…

  15. The SN-GRB-Cosmic Ray Connection

    NASA Astrophysics Data System (ADS)

    Dar, Arnon

    2006-02-01

    A unified theory of high energy astrophysical phenomena, which is based onan SN-CR-GRB association and the Cannonball Model of highly relativistic astrophysical jets explains (a) the origin and main properties of the high energy cosmic rays (CRS) at all energies, (b) the origin and main properties of gamma ray bursts (GRBs) (c) the origin of the extragalactic gamma-ray background radiation (GBR), (d) the origin of Galactic and extragalactic magnetic fields (e) the missing heat source in "cooling flow" galaxy clusters.

  16. 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.

  17. 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.

  18. Galactic Cosmic Rays and the Environment

    NASA Astrophysics Data System (ADS)

    Castagnoli, G. Cini

    SH.3.6.14 Galactic Cosmic Rays and the Environment G. Cini Castagnoli, G. Bonino, P. Della Monica, C. Taricco Istituto di Cosmogeofisica, CNR, Corso Fiume 4, 10133 Torino, Italy and Dipartimento di Fisica Generale, Università di Torino, Via P. Giuria 1, 10125 Torino Recently Svensmark and Friis-Christensen (1997) reported an indication that the Galactic Cosmic Rays (GCR) modulated by the solar wind may contribute to the variations in the formation of clouds, which in turn should follow the 11 y solar cycle. On the other hand experiments, conducted in vitro, on the variations of δ3C in symbiont bearing 1 foraminifera have shown that the carbon isotope fractionation from sea water, of the calcite of their shells, depends mainly on the photosynthetic activity (primary productivity) of the symbionts and therefore from the illumination level of their habitat. We have measured and analyzed (Cini Castagnoli et al., 1999) the δ3C profile of G. ruber in an Ionian sea 1 shallow water core very precisely dated. This allows us to acquire information on the ambient light level (connected to the solar irradiance modulation and to the cloud coverage) of the Gallipoli terrace in the past Millenium. The record (1205-1975 AD) of 200 points with time resolution 3.87 years shows a highly significant 11 y cyclicity covariant with Sunspots of amplitude 0.04 ‰ . A test for determining the δ3C-irradiance relation has been 1 13 performed by studying variations of δ C and the percentage annual number of rainy days during the last century in this region. Our results agree with the expectations on the basis of experiments performed in vitro on G. sacculifer ( on G. ruber is not available). The amplitude of the 11 y δ3C signal turns out to be of the order of 1.5 W/m2. This value seems to be 1 quite high (although of the same order) to be directly induced solely by changes in the solar constant, if in past times they were similar to those measured in space during solar cycles 22-23. The

  19. 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.

  20. Cosmic gamma-ray lines

    NASA Technical Reports Server (NTRS)

    Ramaty, R.; Lingenfelter, R. E.

    1986-01-01

    Recent observations of gamma-ray line emissions from gamma-ray bursts, the ISM, the Galactic center, and solar flares are reviewed, and the implications of these observations for high-energy processes in these sources are discussed. Line observations suggest that magnetized neutron stars are probably the best candidate objects for burst sources. Observations of the 1.809-MeV line from Al-26 decay provide evidence for ongoing nucleosynthesis in the Galaxy and information on the spatial distribution of nucleosynthetic sites. The compact 0.511-MeV line source is probably a black hole at or close to the Galactic center. Solar-flare studies have provided new information on the confinement and escape of charged particles at the sun and on multiple acceleration phases in solar flares.

  1. Diffusion-convection function of cosmic rays

    NASA Technical Reports Server (NTRS)

    Zhang, G.; Yang, G.

    1985-01-01

    The fundamental properties and some numerical results of the solution of the diffusion equation of an impulsive cosmic-ray point source in an uniform, unbounded and spherically symmetrical moving medium is presented. The diffusion-convection(D-C) function is an elementary composite function of the solution of the D-C equation for the particles injected impulsively from a diffusive point source into the medium. It is the analytic solution derived by the dimensional method for the propagation equation of solar cosmic rays in the heliosphere, i.e. the interplanetary space. Because of the introduction of convection effect of solar wind, a nonhomogeneous term appears in the propagation equation, it is difficult to express its solution in terms of the ordinary special functions. The research made so far has led to a solution containing only the first order approximation of the convection effect.

  2. 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.

  3. Astroparticle Physics: Detectors for Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Salazar, Humberto; Villaseñor, Luis

    2006-09-01

    We describe the work that we have done over the last decade to design and construct instruments to measure properties of cosmic rays in Mexico. We describe the measurement of the muon lifetime and the ratio of positive to negative muons in the natural background of cosmic ray muons at 2000 m.a.s.l. Next we describe the detection of decaying and crossing muons in a water Cherenkov detector as well as a technique to separate isolated particles. We also describe the detection of isolated muons and electrons in a liquid scintillator detector and their separation. Next we describe the detection of extensive air showers (EAS) with a hybrid detector array consisting of water Cherenkov and liquid scintillator detectors, located at the campus of the University of Puebla. Finally we describe work in progress to detect EAS at 4600 m.a.s.l. with a water Cherenkov detector array and a fluorescence telescope at the Sierra Negra mountain.

  4. 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.

  5. Cosmic Ray Electron Science with GLAST

    SciTech Connect

    Ormes, J.F.; Moiseev, Alexander; /NASA, Goddard

    2007-10-17

    Cosmic ray electrons at high energy carry information about their sources, their diffusion 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 arrival 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.

  6. 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.

  7. The Pierre Auger Cosmic Ray Observatory

    DOE PAGES

    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

  8. 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.

  9. Galactic acceleration of ultrahigh energy cosmic rays

    SciTech Connect

    Colgate, S.A.

    1984-01-01

    Ultrahigh energy cosmic rays are likely to originate in old galaxies because of the difficulty with acceleration in special extragalactic circumstances. An extended magnetic field in the galaxy is necessary to give sufficient time dispersion from supernova events if supernova are the origin of such particles. Acceleration must be either parallel to a magnetic field such as would occur during the initial formation of a magnetic neutron star, or formed in the relativistic supernova envelope shock.

  10. 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.

  11. Catching the highest energy cosmic rays

    NASA Astrophysics Data System (ADS)

    Watson, Alan A.

    2009-04-01

    The Pierre Auger Observatory in the Argentinian pampas is a vast hybrid instrument combining fluorescence telescopes and surface water-Cherenkov detectors, the product of a major international collaboration. This article describes the science that underpins the design and operation of the observatory, now fully functioning nearly 10 years after the start of construction. Early data from the complete array suggest an association between the sources of very high energy cosmic rays and active galactic nuclei.

  12. Scientific Set of Instruments "Solar Cosmic Rays"

    NASA Astrophysics Data System (ADS)

    Kuznetsov, S. N.; Bogomolov, A. V.; Galkin, V. I.; Denisov, Yu. I.; Podorolsky, A. N.; Ryumin, S. P.; Kudela, K.; Rojko, J.

    A set of scientific instruments SCR (Solar Cosmic Rays) was developed by the scientists of SINP MSU and IEP SAS in order to study relations between the radiation conditions in the near-Earth space and solar activity. This set of instruments was installed on board the satellites CORONAS-I and CORONAS-F launched to the orbit on March 2, 1994, and July 30, 2001, respectively. Detailed description of the instruments is presented.

  13. 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.

  14. 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.

  15. EMMA - an underground cosmic-ray experiment

    NASA Astrophysics Data System (ADS)

    Enqvist, T.; Bezrukov, L.; Fynbo, H.; Heikkilä, E.; Inzhechik, L.; Joutsenvaara, J.; Jones, P.; Jämsén, T.; Kalliokoski, T.; Keränen, P.; Kolos, K.; Kuusiniemi, P.; Lubsandorzhiev, B.; Olanterä, L.; Petkov, V.; Räihä, T.; Sarkamo, J.; Trzaska, W.; Usoskin, I.

    2009-12-01

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

  16. Numerical Model for Cosmic Rays Species Production and Propagation in the Galaxy

    NASA Technical Reports Server (NTRS)

    Farahat, Ashraf; Zhang, Ming; Rassoul, Hamid; Connell, J. J.

    2005-01-01

    In recent years, considerable progress has been made in studying the propagation and origin of cosmic rays, as new and more accurate data have become available. Many models have been developed to study cosmic ray interactions and propagation showed flexibility in resembling various astrophysical conditions and good agreement with observational data. However, some astrophysical problems cannot be addressed using these models, such as the stochastic nature of the cosmic rays source, small-scale structures and inhomogeneities in the interstellar gas that can affect radioactive secondary abundance in cosmic rays. We have developed a new model and a corresponding computer code that can address some of these limitations. The model depends on the expansion of the backward stochastic solution of the general diffusion transport equation (Zhang 1999) starting from an observer position to solve a group of diffusion transport equations each of which represents a particular element or isotope of cosmic ray nuclei. In this paper we are focusing on key abundance ratios such as B/C, sub-Fe/Fe, (10)Be/(9)Be, (26)Al/(27)Al, (36)Cl/(37)Cl and (54)Mn/(55)Mn, which all have well established cross sections, to evaluate our model. The effect of inhomogeneity in the interstellar medium is investigated. The contribution of certain cosmic ray nuclei to the production of other nuclei is addressed. The contribution of various galactic locations to the production of cosmic ray nuclei observed at solar system is also investigated.

  17. 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.

  18. Cosmic X-ray background and solitars.

    NASA Astrophysics Data System (ADS)

    Chiu, H.-Y.

    In this paper the authors has examined the observational consequences of a class of new astronomical objects proposed by Friedberg, Lee and Pang, called solitars which are degenerate vacuum states embedded with particles. A study is made to include finite temperature effect and pair creation. Quark is believed to be the only species that can exist in the interior of solitars. Massive quark solitars are primarily X-ray emitters and may account for the large unexplained thermal component of the cosmic X-ray background.

  19. Ultraheavy Cosmic-ray Research and Results from the TIGER instrument

    NASA Astrophysics Data System (ADS)

    Barbier, L.

    This talk will review the current status of research on ultra-heavy UH cosmic-rays those with charge Z 26 above iron The study of these nuclei - which are not produced in conventional stellar nucleosynthesis - is important for understanding both the production of elements in SN explosions and the enduring mystery of the galactic cosmic ray source s The UH cosmic-rays contain a unique mixture of both r-process and s-process nuclei as well as having a wide range of combinations of first-ionization potential and volatility Several key element isotopic ratios need to be well measured to better understand the role of volatility in the cosmic-ray source s The talk will conclude with presentation of the latest data and analysis from the Trans-Iron Galactic Element Recorder TIGER instrument which has made two balloon flights over Antarctica totaling 50 days and has collected approximately 40000 events with charge greater than 26

  20. Stable laws and cosmic ray physics

    NASA Astrophysics Data System (ADS)

    Genolini, Y.; Salati, P.; Serpico, P. D.; Taillet, R.

    2017-04-01

    Context. In the new "precision era" for cosmic ray astrophysics, scientists making theoretical predictions cannot content themselves with average trends, but need to correctly take into account intrinsic uncertainties. The space-time discreteness of the cosmic ray sources, together with a substantial ignorance of their precise epochs and locations (with the possible exception of the most recent and close ones) play an important role in this sense. Aims: We elaborate a statistical theory to deal with this problem, relating the composite probability P(Ψ) to obtain a flux Ψ at the Earth and the single-source probability p(ψ) to contribute with a flux ψ. The main difficulty arises from the fact that p(ψ) is a "heavy tail" distribution, characterized by power-law or broken power-law behavior up to very large fluxes, for which the central limit theorem does not hold, and leading to distributions different from Gaussian. The functional form of the distribution for the aggregated flux is nonetheless unchanged by its own convolution, that is, it belongs to the so-called stable laws class. Methods: We analytically discuss the regime of validity of the stable laws associated with the distributions arising in cosmic ray astrophysics, as well as the limitations to the treatment imposed by causal considerations and partial source catalog knowledge. We validate our results with extensive Monte Carlo simulations, for different regimes of propagation parameters and energies. Results: We find that relatively simple recipes provide a satisfactory description of the probability P(Ψ). We also find that a naive Gaussian fit to simulation results would underestimate the probability of very large fluxes, that is, several times above the average, while overestimating the probability of relatively milder excursions. At large energies, large flux fluctuations are prevented by causal considerations, while at low energies, a partial knowledge of the recent and nearby population of

  1. Cosmic-ray half-life of {sup 144}Pm

    SciTech Connect

    Zaerpoor, K.; Dragowsky, M.R.; Krane, K.S.; Chan, Y.D.; Isaac, M.C.; Larimer, R.M.; Macchiavelli, A.O.; Macleod, R.W.; Norman, E.B.; DiGregorio, D.E.; Hindi, M.M.; Robinson, S.J.; Miocinovic, P.

    1998-04-01

    In order to test the possibility of using {sup 144}Pm as a clock to measure the mean cosmic-ray confinement time in the Galaxy, we counted a highly purified 1.4 {mu}Ci source of this isotope in GAMMASPHERE and searched for its astrophysically interesting {beta}{sup +} decay branch through the observation of positron-annihilation {gamma} rays in coincidence with the characteristic 697-keV {gamma} ray. Analysis of 57 h of source counting and 15 h of background shows no net signal and results in an upper limit of 3.7 of 511-511-697 keV coincident events. From this result we establish a 90{percent} confidence level upper limit on the branch for this decay mode to be 7.4{times}10{sup {minus}6}{percent}. The implications of this result for the {sup 144}Pm cosmic-ray chronometer problem are discussed. {copyright} {ital 1998} {ital The American Physical Society}

  2. 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.

  3. 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.

  4. 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.

  5. Galactic cosmic-ray induced production of lithium in the Small Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Ćiprijanović, A.

    2016-12-01

    Recently, the first lithium detection outside of the Milky Way was made in low-metallicity gas of the Small Magellanic Cloud, which was at the level of the expected primordial value. Part of the observed lithium in any environment has primordial origin, but there is always some post-BBN (Big Bang Nucleosynthesis) contamination, since lithium can also be produced in cosmic-ray interactions with the interstellar medium. Using the fact that processes involving cosmic rays produce lithium, but also gamma rays through neutral pion decay, we use the Small Magellanic Cloud gamma-ray observations by Fermi-LAT to make predictions on the amount of lithium in this galaxy that was produced by galactic cosmic rays accelerated in supernova remnants. By including both fusion processes, as well as spallation of heavier nuclei, we find that galactic cosmic rays could produce a very small amount of lithium. In the case of 6Li isotope (which should only be produced by cosmic rays) we can only explain 0.16% of the measured abundance. If these cosmic rays are indeed responsible for such small lithium production, observed abundances could be the result of some other sources, which are discussed in the paper.

  6. Long term variability of the cosmic ray intensity

    NASA Technical Reports Server (NTRS)

    Bhat, C. L.; Houston, B. P.; Mayer, C. J.; Wolfendale, A. W.

    1985-01-01

    In a previous paper Bhat, et al., assess the evidence for the continuing acceleration of cosmic rays in the Loop I supernova remnant. The enhanced gamma-ray emission is found consistent with the Blandford and Cowie model for particle acceleration at the remnant shock wave. The contributions of other supernovae remnants to the galactic cosmic ray energy density are now considered, paying anisotropy of cosmic rays accelerated by local supernovae ( 100 pc). The results are compared with geophysical data on the fluctuations in the cosmic ray intensity over the previous one billion years.

  7. 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).

  8. Key scientific problems from Cosmic Ray History

    NASA Astrophysics Data System (ADS)

    Lev, Dorman

    2016-07-01

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

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

    SciTech Connect

    Reedy, R.C.

    1981-06-15

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

  10. A measurement of the energy spectra and relative abundance of the cosmic-ray H and He isotopes over a broad energy range

    NASA Technical Reports Server (NTRS)

    Webber, W. R.; Yushak, S. M.

    1983-01-01

    The measurements reported of these isotopes were made using two sets of detectors during the same minimum modulation period in 1977. One measurement was made with a balloon-borne telescope, the other with telescopes on the Voyager spacecraft. It is noted that together they provide the widest energy range yet available for studying these isotopes: 14-150 MeV per nucleon for H2 and 10-290 MeV per nucleon for He-3. The simultaneous helium isotope observations are used to give a mutually consistent picture of galactic propagation and solar modulation. The data define the form of the interstellar H-1 and He-4 spectra, an interstellar matter path length for both H-1 and He-4, and a total residual modulation for He-4. The H-2 observations suggest a picture that is very similar for the galactic propagation of H-1 and He-4.

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

    NASA Astrophysics Data System (ADS)

    Zweibel, Ellen G.

    2017-05-01

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

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

    PubMed

    Zweibel, Ellen G

    2017-05-01

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

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

    PubMed Central

    Zweibel, Ellen G.

    2017-01-01

    Star formation and supermassive black hole growth in galaxies appear to be self-limiting. The mechanisms for self-regulation are known as feedback. Cosmic rays, the relativistic particle component of interstellar and intergalactic plasma, are among the agents of feedback. Because cosmic rays are virtually collisionless in the plasma environments of interest, their interaction with the ambient medium is primarily mediated by large scale magnetic fields and kinetic scale plasma waves. Because kinetic scales are much smaller than global scales, this interaction is most conveniently described by fluid models. In this paper, I discuss the kinetic theory and the classical theory of cosmic ray hydrodynamics (CCRH) which follows from assuming cosmic rays interact only with self-excited waves. I generalize CCRH to generalized cosmic ray hydrodynamics, which accommodates interactions with extrinsic turbulence, present examples of cosmic ray feedback, and assess where progress is needed. PMID:28579734

  14. Are cosmic rays effective for ionization of the solar nebula?

    NASA Technical Reports Server (NTRS)

    Dolginov, A. Z.; Stepinski, T. F.

    1993-01-01

    In this paper, we argue that the effectiveness of cosmic rays to ionize the bulk of the nebular gas may be further impaired by the influence of the magnetic field on the propagation of cosmic rays. When cosmic rays enter the nebular disk they ionize the gas and make the dynamo generation of magnetic fields possible. However, once magnetic fields are embedded in the nebular gas, the upcoming cosmic rays can no longer penetrate directly into the nebular disk because they start to interact with the magnetic field and lose their energy before propagating significantly toward the midplane. That, in turn, undercuts the ionization source within the bulk of the gas stopping the dynamo action. Nebular dynamo models ignored this back reaction of magnetic fields on cosmic rays. We calculate this back reaction effect, but for the sake of mathematical simplicity, we ignore the effect of magnetic field weakening due to diminishing ionization by cosmic rays.

  15. 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.

  16. Protostellar Cosmic Rays and Extinct Radioactivities in Meteorites

    SciTech Connect

    Lee, T.; Shu, F.H.; Shang, H.; Glassgold, A.E.; Rehm, K.E.

    1998-10-01

    Calcium-aluminum{endash}rich inclusions (CAIs) and chondrules of chondritic meteorites may originate with the melting of dustballs launched by a magnetically driven bipolar outflow from the inner edge of the primitive solar nebula. Bombardment by protostellar cosmic rays may make the rock precursors of CAIs and chondrules radioactive, producing radionuclides found in meteorites that are difficult to obtain with other mechanisms. Reasonable scalings from the observed hard X-rays for the cosmic-ray protons released by flares in young stellar objects yield the correct amounts of {sup 41}Ca, {sup 53}Mn, and {sup 138}La inferred for meteorites, but proton- and {alpha}-induced transformations underproduce {sup 26}Al by a factor of about 20. The missing {sup 26}Al may be synthesized by {sup 3}He nuclei accelerated in impulsive flares reacting primarily with {sup 24}Mg, an abundant isotope in the target precursor rocks. The mechanism allows a simple explanation for the very different ratios of {sup 26}Al/{sup 27}Al inferred for normal CAIs, CAIs with fractionated and unidentified nuclear (FUN) anomalies, and chondrules. The overproduction of {sup 41}Ca by analogous {sup 3}He reactions and the case of {sup 60}Fe inferred for eucritic meteorites require special interpretations in this picture. {copyright} {ital {copyright} 1998.} {ital The American Astronomical Society}

  17. Acoustic detection of cosmic-ray air showers.

    PubMed

    Barrett, W L

    1978-11-17

    The signal strength, bandwidth, and detection range of acoustic pulses generated by cosmic-ray air showers striking a water surface are calculated. These signals are strong enough to be audible to a submerged swimmer. The phenomena may be useful for studying very-high-energy cosmic rays and may help answer the important question of whether the origin of cosmic rays is extragalactic or galactic.

  18. 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.

  19. The Cosmic-Ray Luminosity of the Galaxy

    NASA Astrophysics Data System (ADS)

    Dogiel, V. A.; Schönfelder, V.; Strong, A. W.

    2002-06-01

    The total cosmic-ray luminosity of the Galaxy is one of the main parameters that strongly constrain possible models of the origin of cosmic rays. Recently, Dar & De Rújula suggested a luminosity that is 2 orders of magnitude larger than the standard estimate. If this estimate were correct, it would completely change our conception of the origin of cosmic rays. From a number of different arguments, however, we show that the estimate of Dar & Rújula is too high.

  20. Compact cosmic ray detector for unattended atmospheric ionization monitoring.

    PubMed

    Aplin, K L; Harrison, R G

    2010-12-01

    Two vertical cosmic ray telescopes for atmospheric cosmic ray ionization event detection are compared. Counter A, designed for low power remote use, was deployed in the Welsh mountains; its event rate increased with altitude as expected from atmospheric cosmic ray absorption. Independently, Counter B's event rate was found to vary with incoming particle acceptance angle. Simultaneous co-located comparison of both telescopes exposed to atmospheric ionization showed a linear relationship between their event rates.

  1. New approach to cosmic ray investigations above the knee

    NASA Astrophysics Data System (ADS)

    Bogdanov, A. G.; Kokoulin, R. P.; Petrukhin, A. A.

    2016-05-01

    It is assumed that at energies around the knee the nucleus-nucleus interaction is drastically changed due to production of blobs of quark-gluon matter with very large orbital momentum. This approach allows explain all so-called unusual events observed in cosmic rays and gives a new connection between results of EAS investigations and energy spectrum and mass composition of primary cosmic rays. To check this approach, the experiments in cosmic rays and at LHC are proposed.

  2. 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.

  3. 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.

  4. Radioresistance of Adenine to Cosmic Rays.

    PubMed

    Vignoli Muniz, Gabriel S; Mejía, Christian F; Martinez, Rafael; Auge, Basile; Rothard, Hermann; Domaracka, Alicja; Boduch, Philippe

    2017-04-01

    The presence of nucleobases in carbonaceous meteorites on Earth is an indication of the existence of this class of molecules in outer space. However, space is permeated by ionizing radiation, which can have damaging effects on these molecules. Adenine is a purine nucleobase that amalgamates important biomolecules such as DNA, RNA, and ATP. Adenine has a unique importance in biochemistry and therefore life. The aim of this work was to study the effects of cosmic ray analogues on solid adenine and estimate its survival when exposed to corpuscular radiation. Adenine films were irradiated at GANIL (Caen, France) and GSI (Darmstadt, Germany) by 820 MeV Kr(33+), 190 MeV Ca(10+), 92 MeV Xe(23+), and 12 MeV C(4+) ion beams at low temperature. The evolution of adenine molecules under heavy ion irradiation was studied by IR absorption spectroscopy as a function of projectile fluence. It was found that the adenine destruction cross section (σd) follows an electronic stopping power (Se) power law under the form: CSe(n); C is a constant, and the exponential n is a dimensionless quantity. Using the equation above to fit our results, we determined σd = 4 × 10(-17) Se(1.17), with Se in kiloelectronvolts per micrometer (keV μm(-1)). New IR absorption bands arise under irradiation of adenine and can be attributed to HCN, CN(-), C2H4N4, CH3CN, and (CH3)3CNC. These findings may help to understand the stability and chemistry related to complex organic molecules in space. The half-life of solid adenine exposed to the simulated interstellar medium cosmic ray flux was estimated as (10 ± 8) × 10(6) years. Key Words: Heavy ions-Infrared spectroscopy-Astrochemistry-Cosmic rays-Nucleobases-Adenine. Astrobiology 17, 298-308.

  5. The Cosmic Ray Energetics And Mass Project

    NASA Astrophysics Data System (ADS)

    Seo, Eun-Suk; Iss-Cream Collaboration

    2017-01-01

    The balloon-borne Cosmic Ray Energetics And Mass (CREAM) experiment was flown for 161 days in six flights over Antarctica, the longest known exposure for a single balloon project. Elemental spectra were measured for Z = 1- 26 nuclei over a wide energy range from 1010 to >1014 eV. Building on the success of those balloon flights, one of the two balloon payloads was transformed for exposure on the International Space Station (ISS) Japanese Experiment Module Exposed Facility (JEM-EF). This ISS-CREAM instrument is configured with redundant and complementary particle detectors. The four layers of its finely segmented Silicon Charge Detector provide precise charge measurements, and its ionization calorimeter provides energy measurements. In addition, scintillator-based Top and Bottom Counting Detectors and the Boronated Scintillator Detector distinguish electrons from nuclei. An order of magnitude increase in data collecting power is expected to reach the highest energies practical with direct measurements. Following completion of its qualification tests at NASA Goddard Space Flight Center, the ISS-CREAM payload was delivered to NASA Kennedy Space Center in August 2015 to await its launch to the ISS. While waiting for ISS-CREAM to launch, the other balloon payload including a Transition Radiation Detector, which is too large for the JEM-EF envelope, has been prepared for another Antarctic balloon flight in 2016. This so-called Boron And Carbon Cosmic rays in the Upper Stratosphere (BACCUS) payload will investigate cosmic ray propagation history. The overall project status and future plans will be presented.

  6. Cosmic rays, gamma rays and synchrotron radiation from the Galaxy

    DOE PAGES

    Orlando, Elena

    2012-07-30

    Galactic cosmic rays (CR), interstellar gamma-ray emission and synchrotron radiation are related topics. CR electrons propagate in the Galaxy and interact with the interstellar medium, producing inverse-Compton emission measured in gamma rays and synchrotron emission measured in radio. I present an overview of the latest results with Fermi/LAT on the gamma-ray diffuse emission induced by CR nuclei and electrons. Then I focus on the recent complementary studies of the synchrotron emission in the light of the latest gamma-ray results. Relevant observables include spectral indices and their variations, using surveys over a wide range of radio frequencies. As a result, thismore » paper emphasizes the importance of using the parallel study of gamma rays and synchrotron radiation in order to constrain the low-energy interstellar CR electron spectrum, models of propagation of CRs, and magnetic fields.« less

  7. Cosmic rays, gamma rays and synchrotron radiation from the Galaxy

    SciTech Connect

    Orlando, Elena

    2012-07-30

    Galactic cosmic rays (CR), interstellar gamma-ray emission and synchrotron radiation are related topics. CR electrons propagate in the Galaxy and interact with the interstellar medium, producing inverse-Compton emission measured in gamma rays and synchrotron emission measured in radio. I present an overview of the latest results with Fermi/LAT on the gamma-ray diffuse emission induced by CR nuclei and electrons. Then I focus on the recent complementary studies of the synchrotron emission in the light of the latest gamma-ray results. Relevant observables include spectral indices and their variations, using surveys over a wide range of radio frequencies. As a result, this paper emphasizes the importance of using the parallel study of gamma rays and synchrotron radiation in order to constrain the low-energy interstellar CR electron spectrum, models of propagation of CRs, and magnetic fields.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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

  16. Investigation of cosmic-ray variations using the Elbrus spectrograph

    NASA Astrophysics Data System (ADS)

    Baisultanova, L. M.; Daova, S. P.; Dorman, L. I.; Stremoukhov, V. M.; Khamirzov, Kh. M.

    The soft-muon detector and the muon-neutron detector at the Elbrus cosmic-ray-measuring facility are described. The expected contribution of geomagnetic effects to various classes of cosmic-ray variations is estimated. Amplitudes and phases of the first harmonic of the solar-diurnal variation of cosmic rays are determined. Data on cosmic-ray modulation in interplanetary space are interpreted on the basis of a theory of fast-particle propagation in a moving magnetoplasma in the presence of additional scatterers, moving with a velocity that differs significantly from that of the background plasma.

  17. 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.

  18. 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.

  19. 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

  20. Cosmic Rays in Star-Forming Galaxies

    NASA Astrophysics Data System (ADS)

    Lacki, Brian Cameron

    Cosmic rays (CRs) are high energy particles that are found wherever in the Universe star formation is occurring. I investigate several problems in the propagation of CRs in star-forming galaxies. By applying analytic models and numerically solving the "leaky box" differential equation, I calculate the population of primary and secondary CR protons, electrons and positrons in model star-forming galaxies and their nonthermal emission. Observations show that the synchrotron radio emission of star-forming galaxies grows linearly with the infrared emission from dust-obscured young stars; this is the FIR-radio correlation (FRC). To explain the correlation, I constructed one-zone models of galaxies over the dynamic range of the FRC. I found that the FRC is caused by conspiracies of several factors, including CR escape from galaxies, ultraviolet (UV) dust opacity, non-synchrotron cooling, and secondary electrons and positrons generated by CR protons. The conspiracies have great implications for the evolution of the FRC at high redshift, preserving it and allowing variations in the FIR-radio ratio for submillimeter galaxies. Recent gamma-ray observations of M82 and NGC 253 indicate that CR protons lose much of their energy to collisions in these galaxies' dense gas, where they generate unstable pions that decay into gamma rays and secondary particles. The ratio of gamma-ray to radio luminosity indicates that secondary electrons mostly do not cool by synchrotron emission, supporting a conspiracy origin of the FRC. I also compare the intensities of the diffuse cosmic gamma-ray background to the X-ray and radio backgrounds. From this comparison, I find that Inverse Compton is a minority of the X-ray background, and that the radio background is probably not from starbursts. Finally, I modeled the nonthermal X-ray emission from starburst galaxies, both synchrotron from TeV electrons and Inverse Compton from GeV electrons. The synchrotron emission is enhanced by gamma-gamma pair

  1. Cosmic Rays from Gamma Ray Bursts in the Galaxy

    DTIC Science & Technology

    2005-01-01

    supernova when its core collapses to a black hole. Most core-collapse supernovae , by contrast, form neutron stars. In either case, the supernova ...ions. Th e supernovae that form neutron stars are thought to accelerate cosmic rays to energies reaching 1014 eV. Th e much more energetic GRB shock...universe in this model. Over the age of the Galaxy, there is a good chance that a nearby powerful GRB, with a jet oriented toward Earth , could have

  2. Cosmic rays in a galactic breeze

    NASA Astrophysics Data System (ADS)

    Taylor, Andrew M.; Giacinti, Gwenael

    2017-01-01

    Motivated by the discovery of the nonthermal Fermi bubble features both below and above the Galactic plane, we investigate a scenario in which these bubbles are formed through galacto-centric outflow. Cosmic rays (CR) both diffusing and advecting within a galactic breeze outflow, interacting with the ambient gas present, give rise to γ -ray emission, providing an approximately flat surface brightness profile of this emission, as observed. Applying the same outflow profile further out within the disk, the resultant effects on the observable CR spectral properties are determined. A hardening in the spectra due to the competition of advective and diffusive propagation within a particular energy range is noted, even in the limiting case of equal CR diffusion coefficients in the disk and halo. It is postulated that this hardening effect may relate to the observed hardening feature in the CR spectrum at a rigidity of ≈200 GV .

  3. Cosmic ray studies with the MINOS detectors

    NASA Astrophysics Data System (ADS)

    Habig, Alec; Minos Collaboration

    2008-11-01

    The MINOS experiment uses two layered scintillator and steel detectors along with a muon neutrino beam to search for νμ disappearance, and thus neutrino oscillations. The Far Detector ('FD') is situated in a former iron mine in the Soudan Underground Mine State Park in Northeastern MN, 700 m (2070 mwe) below the surface. This 5.4 kt steel/scintillator calorimeter measures the neutrino flux after they have traveled the 735 km baseline. It also detects atmospheric neutrinos at a rate of several per week, and is the first magnetized atmospheric neutrino detector, able to discriminate between νμ and νμ on an event-by-event basis. The similar 1 kt Near Detector ('ND') is 100 m (220 mwe) underground at Fermilab. This poster discusses the science being done with the high energy cosmic ray muons which penetrate the rock overburden and are seen by the detectors. The typical surface energy of those seen at the FD are ~1 TeV (coming from ~8 TeV primary cosmic rays) and ~110 GeV at the ND (~900 GeV primaries).

  4. 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.

  5. 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.

  6. Solar, Geomagnetic and Cosmic Ray Intensity Changes

    NASA Astrophysics Data System (ADS)

    Pérez-Peraza, J. A.; Kavlakov, S.; Gallegos-Cruz, A.; Azpra-Romero, E.; Delgado-Delgado, O.; Villaca-Cruz, F.

    Recently it was shown that there exist specific changes in the cosmic ray intensity and some solar and geomagnetic parameters during the days preceding the hurricane appearances over the North Atlantic Ocean To understand better these phenomena data were elaborated for all hurricanes born not only over the Atlantic but also over the Pacific waters in the last 55 years and hit the Mexican borders As basic hurricane parameters the maximum rotational velocity and the estimated total energy were used To avoid any interference all hurricanes overlapping the preceding ones with more than 20 days were not included Then the behaviour of the Cosmic Ray CR intensity the Sunspot SS numbers and the geomagnetic parameters AP and KP in 35 days prior and 20 days after of the cyclone start were investigated The CR SS AP and KP showed much more intensive disturbances in the periods preceding and following the hurricane appearance For SS this disturbance gradually increase with the hurricane strength A characteristic peak in the CR intensity appears before the hurricane start But it place varies between 5 and 20 days before that start Such a peak in the SS is statistically more stable For major hurricanes it appears 7-9 days in advance The AP and the KP show similar changes

  7. 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.

  8. Lunar monitoring outpost of cosmic rays

    NASA Astrophysics Data System (ADS)

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

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

  9. X-rays during the Cosmic Dawn

    NASA Astrophysics Data System (ADS)

    Mesinger, Andrei

    2017-08-01

    X-rays play a fundamental role in shaping the early Universe. X-rays from the first galaxies (originating from high mass X-ray binaries, the hot interstellar medium, or other sources) are expected to dominate the heating of the intergalactic medium (IGM), even before the epoch of reionization (EoR). This epoch of heating (EoH) has a dramatic imprint in the cosmic 21-cm signal. I will show how even simple metrics of the 21-cm signal during the EoH can tell us about the X-ray luminosities and SEDs of the first galaxies in our Universe. Upcoming 21-cm interferometers, HERA and SKA, will allow us to go even further, eventually providing a 3D map of the EoH. In order to take advantage of this, we created a new analysis tool for constraining the X-ray properties of the first sources in our Universe, all within a fully-Bayesian framework.

  10. Signatures of a Two Million Year Old Supernova in the Spectra of Cosmic Ray Protons, Antiprotons, and Positrons.

    PubMed

    Kachelrieß, M; Neronov, A; Semikoz, D V

    2015-10-30

    The locally observed cosmic ray spectrum has several puzzling features, such as the excess of positrons and antiprotons above ~20  GeV and the discrepancy in the slopes of the spectra of cosmic ray protons and heavier nuclei in the TeV-PeV energy range. We show that these features are consistently explained by a nearby source which was active approximately two million years ago and has injected (2-3)×10^{50} erg in cosmic rays. The transient nature of the source and its overall energy budget point to the supernova origin of this local cosmic ray source. The age of the supernova suggests that the local cosmic ray injection was produced by the same supernova that has deposited ^{60}Fe isotopes in the deep ocean crust.

  11. Cosmic-ray-produced Kr in St. Severin core AIII

    NASA Technical Reports Server (NTRS)

    Lavielle, B.; Marti, K.

    1988-01-01

    Kr isotopic abundances in 10 samples from core AIII of the St. Severin chondrite are reported, and the variation with depth of cosmic-ray produced Kr is discussed. It is shown that the ratio (Kr-78/Kr-83)c changes with depth and can be used as an irradiation hardness monitor. Cosmic-ray-produced Kr and Ne in the St. Severin core are compared with ratios observed in bulk chondrites. A linear correlation between (Ne-22/Ne-21)c and (Kr-78/Kr-83)c exists for bulk samples of chondrites of varying preatmospheric size, but does not exist in the St. Severin core. The calculated Kr-83 production rates, P83, are similar in H, L, and LL chondrites for samples of comparable shielding conditions. However, P83 rates increase by a factor of about 2 with shielding depth. The maximum observed P83 values correspond to (Kr-78/Kr-83)c factor of about 2 with shielding depth. The maximum observed P83 values correspond to (Kr-78/Kr-83)c less than about 0.14.

  12. OB associations and the nonuniversality of the cosmic abundances - Implications for cosmic rays and meteorites

    NASA Technical Reports Server (NTRS)

    Olive, K. A.; Schramm, D. N.

    1982-01-01

    The formation of the solar system inside an OB association is examined with particular attention to the elemental abundances which would have been ejected by the association's first few supernovae. It is found that the solar system material may have been significantly contaminated by these supernovae and thus the average interstellar composition may differ from the solar system composition. In particular, we find that many of the so-called isotopic and elemental abundance anomalies (e.g., Ne, C, O, s-process/r-process, etc.) found in meteoritic inclusions and in cosmic rays may be more representative of the average interstellar abundance. In other words, it may be that the average solar system abundances are what is 'anomalous'.

  13. RECORD-SETTING COSMIC-RAY INTENSITIES IN 2009 AND 2010

    SciTech Connect

    Mewaldt, R. A.; Davis, A. J.; Leske, R. A.; Stone, E. C.; Cummings, A. C.; Labrador, A. W.; Lave, K. A.; Binns, W. R.; Israel, M. H.; Wiedenbeck, M. E.; Christian, E. R.; De Nolfo, G. A.; Von Rosenvinge, T. T.

    2010-11-01

    We report measurements of record-setting intensities of cosmic-ray nuclei from C to Fe, made with the Cosmic Ray Isotope Spectrometer carried on the Advanced Composition Explorer in orbit about the inner Sun-Earth Lagrangian point. In the energy interval from {approx}70 to {approx}450 MeV nucleon{sup -1}, near the peak in the near-Earth cosmic-ray spectrum, the measured intensities of major species from C to Fe were each 20%-26% greater in late 2009 than in the 1997-1998 minimum and previous solar minima of the space age (1957-1997). The elevated intensities reported here and also at neutron monitor energies were undoubtedly due to several unusual aspects of the solar cycle 23/24 minimum, including record-low interplanetary magnetic field (IMF) intensities, an extended period of reduced IMF turbulence, reduced solar-wind dynamic pressure, and extremely low solar activity during an extended solar minimum. The estimated parallel diffusion coefficient for cosmic-ray transport based on measured solar-wind properties was 44% greater in 2009 than in the 1997-1998 solar-minimum period. In addition, the weaker IMF should result in higher cosmic-ray drift velocities. Cosmic-ray intensity variations at 1 AU are found to lag IMF variations by 2-3 solar rotations, indicating that significant solar modulation occurs inside {approx}20 AU, consistent with earlier galactic cosmic-ray radial-gradient measurements. In 2010, the intensities suddenly decreased to 1997 levels following increases in solar activity and in the inclination of the heliospheric current sheet. We describe the conditions that gave cosmic rays greater access to the inner solar system and discuss some of their implications.

  14. 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).

  15. 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.

  16. 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.

  17. Cerenkov detectors for cosmic ray telescopes employing the Cerenkov x total energy technique of mass identification

    NASA Technical Reports Server (NTRS)

    Webber, W. R.; Kish, J. C.

    1983-01-01

    Considerable progress has been made regarding the evolution of the 'Cerenkov x total energy technique' for mass identification of cosmic ray nuclei since the introduction of telescopes employing this technique by Webber et al. (1973). Thus, significant improvements in mass resolution have been made. These improvements are mainly related to the resolution of the Cerenkov counter. The present investigation is, therefore, concerned with the properties of various types of Cerenkov detectors. In addition, a description is provided of the characteristics of a large area (approximately 0.5 sq m-ster) cosmic ray isotope telescope, which is being developed for use on balloons or spacecraft.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Modulation of Cosmic Ray Precipitation Related to Climate

    NASA Technical Reports Server (NTRS)

    Feynman, J.; Ruzmaikin, A.

    1998-01-01

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

  3. Energetic-Particle Populations and Cosmic-Ray Entry.

    DTIC Science & Technology

    1981-03-17

    H., E. Fl~ickiger. H. von Mandach , and M. Arens, Determina- tion of the ring current radii from cosmic ray neutron monitor data for the 17 December... Mandach , and M. Arens, Determination of the ring current radii from cosmic ray neutron monitor data for the 17 December 1971 magnetic storm, Planet. Space

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Cosmic ray modulation by high-speed solar wind fluxes

    NASA Technical Reports Server (NTRS)

    Dorman, L. I.; Kaminer, N. S.; Kuzmicheva, A. E.; Mymrina, N. V.

    1985-01-01

    Cosmic ray intensity variations connected with recurrent high-speed fluxes (HSF) of solar wind are investigated. The increase of intensity before the Earth gets into a HSF, north-south anisotropy and diurnal variation of cosmic rays inside a HSF as well as the characteristics of Forbush decreases are considered.

  9. 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.

  10. Cosmic Ray Abundance at Aircraft Altitudes in the Earth's Atmosphere

    NASA Astrophysics Data System (ADS)

    Zhou, D.

    1999-08-01

    Recent investigations of cosmic ray primaries and secondaries at aviation altitudes in the Earth's atmosphere include the study of Z≥2 particles along the London-New York flight routes on supersonic aircraft. Preliminary charge spectra will be presented for these nuclei and comparisons will be made with the predictions of cosmic ray transport models in the Earth's atmosphere.

  11. Stopping Cooling Flows with Cosmic-Ray Feedback

    NASA Astrophysics Data System (ADS)

    Mathews, William G.

    2009-04-01

    Multi-Gyr two-dimensional calculations describe the gas dynamical evolution of hot gas in the Virgo cluster resulting from intermittent cavities formed with cosmic rays. Without cosmic rays, the gas evolves into a cooling flow, depositing about 85 solar masses per year of cold gas in the cluster core—such uninhibited cooling conflicts with X-ray spectra and many other observations. When cosmic rays are produced or deposited 10 kpc from the cluster center in bursts of about 1059 erg lasting 20 Myr and spaced at intervals of 200 Myr, the central cooling rate is greatly reduced to {\\dot{M}} ≈ 0.1-1 solar masses per year, consistent with observations. After cosmic rays diffuse through the cavity walls, the ambient gas density is reduced and is buoyantly transported 30-70 kpc out into the cluster. Cosmic rays do not directly heat the gas and the modest shock heating around young cavities is offset by global cooling as the cluster gas expands. After several Gyr the hot gas density and temperature profiles remain similar to those observed, provided the time-averaged cosmic-ray luminosity is about L cr = 2.7 × 1043 erg s-1, approximately equal to the bolometric cooling rate LX within only ~56kpc. If an appreciable fraction of the relativistic cosmic rays is protons, gamma rays produced by pion decay following inelastic p-p collisions may be detected with the Fermi Gamma-Ray Telescope.

  12. 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.

  13. The mass composition of cosmic rays measured with LOFAR

    NASA Astrophysics Data System (ADS)

    Hörandel, Jörg R.; Bonardi, A.; Buitink, S.; Corstanje, A.; Falcke, H.; Mitra, P.; Mulrey, K.; Nelles, A.; Rachen, J. P.; Rossetto, L.; Schellart, P.; Scholten, O.; ter Veen, S.; Thoudam, S.; Trinh, T. N. G.; Winchen, T.

    2017-03-01

    High-energy cosmic rays, impinging on the atmosphere of the Earth initiate cascades of secondary particles, the extensive air showers. The electrons and positrons in the air shower emit electromagnetic radiation. This emission is detected with the LOFAR radio telescope in the frequency range from 30 to 240 MHz. The data are used to determine the properties of the incoming cosmic rays. The radio technique is now routinely used to measure the arrival direction, the energy, and the particle type (atomic mass) of cosmic rays in the energy range from 1017 to 1018 eV. This energy region is of particular astrophysical interest, since in this regime a transition from a Galactic to an extra-galactic origin of cosmic rays is expected. For illustration, the LOFAR results are used to set constraints on models to describe the origin of high-energy cosmic rays.

  14. 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.

  15. 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).

  16. 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

  17. 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.

  18. The galactic cosmic ray ionization rate

    PubMed Central

    Dalgarno, A.

    2006-01-01

    The chemistry that occurs in the interstellar medium in response to cosmic ray ionization is summarized, and a review of the ionization rates that have been derived from measurements of molecular abundances is presented. The successful detection of large abundances of H3+ in diffuse clouds and the recognition that dissociative recombination of H3+ is fast has led to an upward revision of the derived ionization rates. In dense clouds the molecular abundances are sensitive to the depletion of carbon monoxide, atomic oxygen, nitrogen, water, and metals and the presence of large molecules and grains. Measurements of the relative abundances of deuterated species provide information about the ion removal mechanisms, but uncertainties remain. The models, both of dense and diffuse clouds, that are used to interpret the observations may be seriously inadequate. Nevertheless, it appears that the ionization rates differ in dense and diffuse clouds and in the intercloud medium. PMID:16894166

  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. 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.

  1. 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

  2. Stars and Cosmic Rays Observed from Mars

    NASA Image and Video Library

    2004-03-12

    In this five-minute exposure taken from the surface of Mars by NASA Spirit rover, stars appear as streaks due to the rotation of the planet, and instantaneous cosmic-ray hits appear as points of light. Spirit took the image with its panoramic camera on March 11, 2004, after waking up during the martian night for a communication session with NASA's Mars Global Surveyor orbiter. Other exposures were also taken. The images tested the capabilities of the rover for night-sky observations. Scientists will use the results to aid planning for possible future astronomical observations from Mars. The difference in Mars' rotation, compared to Earth's, gives the star trails in this image a different orientation than they would have in a comparable exposure taken from Earth. http://photojournal.jpl.nasa.gov/catalog/PIA05551

  3. The galactic cosmic ray ionization rate.

    PubMed

    Dalgarno, A

    2006-08-15

    The chemistry that occurs in the interstellar medium in response to cosmic ray ionization is summarized, and a review of the ionization rates that have been derived from measurements of molecular abundances is presented. The successful detection of large abundances of H(3)(+) in diffuse clouds and the recognition that dissociative recombination of H(3)(+) is fast has led to an upward revision of the derived ionization rates. In dense clouds the molecular abundances are sensitive to the depletion of carbon monoxide, atomic oxygen, nitrogen, water, and metals and the presence of large molecules and grains. Measurements of the relative abundances of deuterated species provide information about the ion removal mechanisms, but uncertainties remain. The models, both of dense and diffuse clouds, that are used to interpret the observations may be seriously inadequate. Nevertheless, it appears that the ionization rates differ in dense and diffuse clouds and in the intercloud medium.

  4. 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.

  5. 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.

  6. Early Cosmic Ray Research with Balloons

    NASA Astrophysics Data System (ADS)

    Walter, Michael

    2013-06-01

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

  7. 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.

  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. Cosmic Ray Streaming in Galaxy Clusters

    NASA Astrophysics Data System (ADS)

    Wiener, Joshua; Gould Zweibel, Ellen; Oh, Siang P.

    2017-08-01

    The origin of diffuse radio emission in galaxy clusters remains an open question in astrophysics. This emission indicates the presence of cluster-wide magnetic fields and high energy cosmic ray (CR) electrons. I will discuss how the properties of the observed radio emission in clusters are shaped by different CR transport processes, namely CR streaming. Recent work has shown that fast streaming may turn off radio emission on relatively short time scales - a full treatment of magnetohydrodynamic (MHD) wave damping shows that streaming may be even faster than previously thought in high β environments. I will briefly introduce the physics behind CR transport, and present simple numerical simulations of the Coma cluster that predict radio emission, as well as other observable signatures such as gamma radiation that can differentiate between models for the source of the CR electrons.

  10. 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.

  11. Underground cosmic-ray experiment EMMA

    NASA Astrophysics Data System (ADS)

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

    2013-02-01

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

  12. Cosmic ray anisotropies at high energies

    NASA Technical Reports Server (NTRS)

    Martinic, N. J.; Alarcon, A.; Teran, F.

    1986-01-01

    The directional anisotropies of the energetic cosmic ray gas due to the relative motion between the observers frame and the one where the relativistic gas can be assumed isotropic is analyzed. The radiation fluxes formula in the former frame must follow as the Lorentz invariance of dp/E, where p, E are the 4-vector momentum-energy components; dp is the 3-volume element in the momentum space. The anisotropic flux shows in such a case an amplitude, in a rotating earth, smaller than the experimental measurements from say, EAS-arrays for primary particle energies larger than 1.E(14) eV. Further, it is shown that two consecutive Lorentz transformations among three inertial frames exhibit the violation of dp/E invariance between the first and the third systems of reference, due to the Wigner rotation. A discussion of this result in the context of the experimental anisotropic fluxes and its current interpretation is given.

  13. Modeling cosmic ray neutron field measurements

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

    The cosmic ray neutron method was developed for intermediate-scale soil moisture detection, but may potentially be used for other hydrological applications. The neutron signal of different hydrogen pools is poorly understood and separating them is difficult based on neutron measurements alone. Including neutron transport modeling may accommodate this shortcoming. However, measured and modeled neutrons are not directly comparable. Neither the scale nor energy ranges are equivalent, and the exact neutron energy sensitivity of the detectors is unknown. Here a methodology to enable comparability of the measured and modeled neutrons is presented. The usual cosmic ray soil moisture detector measures moderated neutrons by means of a proportional counter surrounded by plastic, making it sensitive to epithermal neutrons. However, that configuration allows for some thermal neutrons to be measured. The thermal contribution can be removed by surrounding the plastic with a layer of cadmium, which absorbs neutrons with energies below 0.5 eV. Likewise, cadmium shielding of a bare detector allows for estimating the epithermal contribution. First, the cadmium difference method is used to determine the fraction of thermal and epithermal neutrons measured by the bare and plastic-shielded detectors, respectively. The cadmium difference method results in linear correction models for measurements by the two detectors, and has the greatest impact on the neutron intensity measured by the moderated detector at the ground surface. Next, conversion factors are obtained relating measured and modeled neutron intensities. Finally, the methodology is tested by modeling the neutron profiles at an agricultural field site and satisfactory agreement to measurements is found.

  14. Radioresistance of Adenine to Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Vignoli Muniz, Gabriel S.; Mejía, Christian F.; Martinez, Rafael; Auge, Basile; Rothard, Hermann; Domaracka, Alicja; Boduch, Philippe

    2017-04-01

    The presence of nucleobases in carbonaceous meteorites on Earth is an indication of the existence of this class of molecules in outer space. However, space is permeated by ionizing radiation, which can have damaging effects on these molecules. Adenine is a purine nucleobase that amalgamates important biomolecules such as DNA, RNA, and ATP. Adenine has a unique importance in biochemistry and therefore life. The aim of this work was to study the effects of cosmic ray analogues on solid adenine and estimate its survival when exposed to corpuscular radiation. Adenine films were irradiated at GANIL (Caen, France) and GSI (Darmstadt, Germany) by 820 MeV Kr33+, 190 MeV Ca10+, 92 MeV Xe23+, and 12 MeV C4+ ion beams at low temperature. The evolution of adenine molecules under heavy ion irradiation was studied by IR absorption spectroscopy as a function of projectile fluence. It was found that the adenine destruction cross section (σd) follows an electronic stopping power (Se) power law under the form: CSen; C is a constant, and the exponential n is a dimensionless quantity. Using the equation above to fit our results, we determined σd = 4 × 10-17 Se1.17, with Se in kiloelectronvolts per micrometer (keV μm-1). New IR absorption bands arise under irradiation of adenine and can be attributed to HCN, CN-, C2H4N4, CH3CN, and (CH3)3CNC. These findings may help to understand the stability and chemistry related to complex organic molecules in space. The half-life of solid adenine exposed to the simulated interstellar medium cosmic ray flux was estimated as (10 ± 8) × 106 years.

  15. 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.

  16. Diffusion of Cosmic-Rays and Gamma-Ray Sources

    NASA Astrophysics Data System (ADS)

    del Pozo, E. D. C.; Torres, D. F.; Rodríguez Marrero, A. Y.

    It is commonly accepted that supernova remnants (SNR) are one of the most probable scenarios of leptonic and hadronic cosmic-ray (CR) acceleration. Such energetic CR can interact with interstellar gas to produce high-energy gamma rays, which can be detected through ground-based air Cherenkov detectors and space telescopes. Here we present a theoretical model that explains the high energy phenomenology of the neighborhood SNR IC 443, as observed with the Major Atmospheric Gamma Imaging Cherenkov (MAGIC) telescope and the Energetic Gamma-ray Experiment Telescope (EGRET). We interpret MAGIC J0616 + 225 as delayed TeV emission of CR diffusing from IC 443, what naturally explains the displacement between EGRET and MAGIC sources.

  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. The NASA cosmic ray program for the 1990's and beyond

    NASA Technical Reports Server (NTRS)

    Ahlen, S. P.; Binns, W. R.; Cherry, M. L.; Gaisser, T. K.; Jones, W. V.; Ling, J. C.; Mewaldt, R. A.; Muller, D.; Ormes, J. O.; Ramaty, R.

    1990-01-01

    The interim report of the 1989 NASA Cosmic Ray Program Working Group is presented. The report summarizes the cosmic ray program for the 1990's, including the recently approved ACE, Astromag, HNC, POEMS, and SAMPEX missions, as well as other key elements of the program. New science themes and candidate missions are identified for the first part of the 21st century, including objectives that might be addressed as part of the Human Exploration Initiative. Among the suggested new thrusts for the 21st century are: an Interstellar Probe into the nearby interstellar medium; a Lunar-Based Calorimeter to measure the cosmic ray composition near 10 exp 16 eV; high-precision element and isotope spectroscopy of ultraheavy elements; and new, more sensitive studies of impulsive solar flare events.

  19. Cosmic-ray composition measurements and cosmic ray background-free γ -ray observations with Cherenkov telescopes

    NASA Astrophysics Data System (ADS)

    Neronov, Andrii; Semikoz, Dmitri V.; Vovk, Ievgen; Mirzoyan, Razmik

    2016-12-01

    The muon component of extensive air showers (EAS) initiated by cosmic-ray particles carries information on the primary particle identity. We show that the muon content of EAS could be measured in a broad energy range from 10-100 TeV up to ultra-high-energy cosmic-ray range using wide field-of-view imaging atmospheric Cherenkov telescopes observing strongly inclined or nearly horizontal EAS from the ground of from high altitude. Cherenkov emission from muons in such EAS forms a distinct component (halo or tail) of the EAS image in the telescope camera. We show that detection of the muon signal could be used to measure composition of the cosmic-ray spectrum in the energy ranges of the knee, the ankle and of the Galactic-to-extragalactic transition. It could also be used to veto the cosmic-ray background in gamma-ray observations. This technique provides a possibility for up to 2 orders of magnitude improvement of sensitivity for γ -ray flux in the energy band above 10 PeV, compared to KASCADE-Grande, and an order-of-magnitude improvement of sensitivity in the multi-EeV energy band, compared to Pierre Auger Observatory.

  20. Cosmic-ray Exposure Ages of Meteorites

    NASA Astrophysics Data System (ADS)

    Herzog, G. F.

    2003-12-01

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

  1. On the Age of Cosmic Rays as Derived from the Abundance of Be-10. Ph.D. Thesis - Maryland Univ.

    NASA Technical Reports Server (NTRS)

    Hagen, F. A.

    1976-01-01

    The isotopic composition of cosmic ray Be, B, C, and N was studied using a new range versus total light technique. Special emphasis was placed on the Be isotopes and in particular, on the radioactive isotope Be-10 due to its mean lifetime against decay. The experiment consisted of a thin trigger scintillator, an acrylic plastic Cerenkov detector and a spark chamber, followed by a totally active stack of 14 scintillation detectors. This stack of scintillators made possible the measurement of range, and also permitted the removal of interacting events by continuously monitoring their identities along their trajectories. The experiment was carried by balloon to atmospheric depths ranging from 3.5 to 5.0 g sq cm residual atmosphere for a total exposure time of 23 hr. Results indicate the survival of ( 55 + or -21) % of the Be-10 in the arriving cosmic rays; the data were interpreted using the leaky box model of cosmic ray propagation.

  2. 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.

  3. Anisotropy of TeV Galactic cosmic rays

    NASA Astrophysics Data System (ADS)

    Zhang, Ming; Pogorelov, Nikolai; Desiati, Paolo; DuVernois, Michael

    2016-07-01

    TeV cosmic rays are significantly deflected by the magnetic field of the heliosphere, and they gain or lose energies in heliospheric electric field that in the meantime drives the motion of plasma. These propagation mechanisms will cause the map of TeV cosmic rays seen at the Earth to look different from the map seen in the local interstellar medium without the presence of the heliosphere. We have developed a method of using Liouville's theorem to map out particle distribution function to Earth from the local interstellar medium, where we assume that the cosmic rays have small pitch-angle anisotropy harmonics up to the second order and a small uniform spatial density gradient. The amount of heliospheric distortion can be determined by tracing the trajectories of cosmic rays propagating through the heliosphere. In this paper, we apply this method to TeV cosmic ray propagation through a MHD-kinetic model of the heliosphere and try to fit observations from Tibet ASgamma and IceCube experiments. We are able to locate features in the TeV cosmic ray anisotropy that are associated with the interstellar magnetic field, hydrogen deflection plane, heliotail, and solar corona. Some of the features are also slightly affected by the solar cycle and interstellar magnetic turbulence. The results provide us powerful tools to explore large-scale heliospheric structures as well as to determine the cosmic ray distribution in the local interstellar medium.

  4. The Heliotail Observed in TeV Cosmic Ray Anisotropy

    NASA Astrophysics Data System (ADS)

    Pogorelov, N.; Borovikov, S.; Zhang, M.

    2016-12-01

    The gyroradius of TeV cosmic rays is comparable to the size of heliosphere. Before they are detected by air shower experiments on the Earth, the trajectories of TeV cosmic rays are deflected by heliospheric magnetic field from its original interstellar pattern and they gain or lose energies in the motional electric field of the heliospheric plama. These propagation mechanisms causes the map of TeV cosmic rays seen at the Earth to look different from the map seen in the local interstellar medium if there were no heliosphere. We have developed a method of using Liouville's theorem to map out cosmic ray anisotropy from the local interstellar medium to the Earth with an assumption that the cosmic rays have a small pitch-angle anisotropy and a small uniform spatial density gradient as expected from diffusive approximation in Galactic propagation. The amount of heliospheric distortion can be determined by tracing the trajectories of cosmic rays propagating through the heliosphere. In this paper, we apply this method to TeV cosmic ray propagation with a MHD-kinetic model of the heliosphere. By fitting observations from Tibet ASγ and IceCube experiments, we are able to determine the cosmic ray distribution in the local interstellar medium. In the meantime, we are able to locate features in the TeV cosmic ray anisotropy that are associated with specific large-scale heliospheric magnetic structure. One of the features indicates that heliotail could be quite long, at least a few thousand AU.

  5. The Status of Cross Section Measurements for Neutron-induced Reactions Needed for Cosmic Ray Studies

    NASA Technical Reports Server (NTRS)

    Sisterson, J. M.

    2003-01-01

    Cosmic ray interactions with lunar rocks and meteorites produce small amounts of radionuclides and stable isotopes. Advances in Accelerator Mass Spectrometry (AMS) allow production rates to be measured routinely in well-documented lunar rocks and meteorites. These measurements are analyzed using theoretical models to learn about the object itself and the history of the cosmic rays that fell on it. Good cross section measurements are essential input to the theoretical calculations. Most primary cosmic ray particles are protons so reliable cross sections for proton-induced reactions are essential. A cross section is deemed accurate if measurements made by different experimenters using different techniques result in consistent values. Most cross sections for proton induced reactions are now well measured. However, good cross section measurements for neutron-induced reactions are still needed. These cross sections are required to fully account for all galactic cosmic ray interactions at depth in an extraterrestrial object. When primary galactic cosmic ray (GCR) particles interact with an object many secondary neutrons are produced, which also initiate spallation reactions. Thus, the total GCR contribution to the overall cosmogenic nuclide archive has to include the contribution from the secondary neutron interactions. Few relevant cross section measurements have been reported for neutron-induced reactions at neutron energies greater than approximately 20 MeV. The status of the cross section measurements using quasi-monoenergetic neutron energies at iThemba LABS, South Africa and white neutron beams at Los Alamos Neutron Science Center (LANSCE), Los Alamos are reported here.

  6. The Status of Cross Section Measurements for Neutron-induced Reactions Needed for Cosmic Ray Studies

    NASA Technical Reports Server (NTRS)

    Sisterson, J. M.

    2003-01-01

    Cosmic ray interactions with lunar rocks and meteorites produce small amounts of radionuclides and stable isotopes. Advances in Accelerator Mass Spectrometry (AMS) allow production rates to be measured routinely in well-documented lunar rocks and meteorites. These measurements are analyzed using theoretical models to learn about the object itself and the history of the cosmic rays that fell on it. Good cross section measurements are essential input to the theoretical calculations. Most primary cosmic ray particles are protons so reliable cross sections for proton-induced reactions are essential. A cross section is deemed accurate if measurements made by different experimenters using different techniques result in consistent values. Most cross sections for proton induced reactions are now well measured. However, good cross section measurements for neutron-induced reactions are still needed. These cross sections are required to fully account for all galactic cosmic ray interactions at depth in an extraterrestrial object. When primary galactic cosmic ray (GCR) particles interact with an object many secondary neutrons are produced, which also initiate spallation reactions. Thus, the total GCR contribution to the overall cosmogenic nuclide archive has to include the contribution from the secondary neutron interactions. Few relevant cross section measurements have been reported for neutron-induced reactions at neutron energies greater than approximately 20 MeV. The status of the cross section measurements using quasi-monoenergetic neutron energies at iThemba LABS, South Africa and white neutron beams at Los Alamos Neutron Science Center (LANSCE), Los Alamos are reported here.

  7. Gamma rays from grazing incidence cosmic rays in the earth's atmosphere

    NASA Technical Reports Server (NTRS)

    Ulmer, Andrew

    1994-01-01

    Interactions of grazing incidence, ultra high-energy cosmic rays with the earth's atmosphere may provide a new method of studying energetic cosmic rays with gamma-ray satellites. It is found that these cosmic ray interactions may produce gamma-rays on millisecond timescales which may be detectable by satellites. An extremely low gamma-ray background for transient gamma-ray events and a large area of interaction, the earth's surface, make the scheme plausible. The effective cross section of detection of interactions for cosmic rays above 10(exp 20) eV is found to be more than two orders of magnitude higher than Earth-based detection techniques. This method may eventually offer an efficient way of probing this region of the cosmic-ray energy spectrum where events are scarce. In this paper, a conceptual model is presented for the production of short bursts of gamma-rays based on these grazing incidence encounters with the Earth's atmosphere.

  8. Relativistic rise measurement for heavy cosmic rays in xenon

    NASA Technical Reports Server (NTRS)

    Gregory, J. C.; Parnell, T. A.; Watts, J., Jr.

    1982-01-01

    Potential advantages of the use of the relativistic rise of energy loss in gas-filled counters for cosmic ray energy measurement have been noted by Tueller et al. (1979) and Gregory and Parnell (1979). Gregory and Parnell have reported measurements on the relativistic rise for cosmic ray iron nuclei in parallel plate ionization chambers 8.4 cm thick filled with a xenon and methane mixture. The present investigation is concerned with the observed rise and ionization signal fluctuations for a sample of elements from carbon through iron in the cosmic rays. The results are compared with a calculation of the energy deposit within the ion chamber.

  9. Cosmic-ray acceleration at stellar wind terminal shocks

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

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

  10. AMS results on positrons and antiprotons in cosmic rays

    NASA Astrophysics Data System (ADS)

    Kounine, Andrei; AMS Collaboration

    2017-01-01

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

  11. SMALL-SCALE ANISOTROPIES OF COSMIC RAYS FROM RELATIVE DIFFUSION

    SciTech Connect

    Ahlers, Markus; Mertsch, Philipp

    2015-12-10

    The arrival directions of multi-TeV cosmic rays show significant anisotropies at small angular scales. It has been argued that this small-scale structure can naturally arise from cosmic ray scattering in local turbulent magnetic fields that distort a global dipole anisotropy set by diffusion. We study this effect in terms of the power spectrum of cosmic ray arrival directions and show that the strength of small-scale anisotropies is related to properties of relative diffusion. We provide a formalism for how these power spectra can be inferred from simulations and motivate a simple analytic extension of the ensemble-averaged diffusion equation that can account for the effect.

  12. Global modulation of cosmic rays in the heliosphere

    NASA Astrophysics Data System (ADS)

    Potgieter, Marius

    2016-07-01

    It is possible, now for the first time, to describe the total, global modulation of cosmic rays in the heliosphere using Voyager observations from the Earth to the heliopause and from the PAMELA space mission at the Earth, in comparison with comprehensive numerical models. The very local interstellar spectra for several cosmic ray species have become much better known so that together with knowledge of where the heliopause is located, comprehensive modelling has taken a huge step forward. New and exciting observations, with ample challenges to theoretical and modelling approaches to the acceleration, transport and modulation of cosmic rays in the heliosphere will be reviewed in this presentation.

  13. Cosmic ray intensity and the tilt of the neutral sheet

    NASA Technical Reports Server (NTRS)

    Saito, T.; Swinson, D. B.

    1985-01-01

    Recent publications have related long-term variations in cosmic ray intensity at the Earth with long term variations in the tilt of the neutral sheet in the inner heliosphere. The tilt of the neutral sheet from 1971 to 1974 is compared with the cosmic ray intensity at Earth, recorded by the Mt. Washington neutron monitor. The remarkable large decreases in cosmic ray intensity which occurred in 1973 and 1974 correlate well with excursions in the tilt of the neutral sheet which occurred earlier during these same two years.

  14. Effect of cosmic ray on global high cloud from MODIS

    NASA Astrophysics Data System (ADS)

    Kim, H.-S.; Choi, Y.-S.

    2012-04-01

    The Earth's climate is affected by not only internal forcings but also external forcings related with solar activities. The energetic particles called "cosmic rays" from outer space have been considered as a potentially important external climate forcing since the first report by Svensemark and Friis-Christensen (1997) which showed a significant correlation between cloudiness and cosmic ray. This correlation is a basis of a couple of hypotheses in microphysical processes: ion-aerosol clear-air mechanism and ion-aerosol near-cloud mechanism. These mechanisms have been either supported or objected by many successive studies, most of which correlated long-term trends of cloud and cosmic ray. However, it is most likely that such methodology is not suitable to find actual connection, because long-term trends of clouds may invite affection by many factors other than cosmic ray. It is therefore necessary to find the relation at shorter time scale, since cosmic ray affect the process of cloud formation in a moment. Here we show spatial distributions of correlation between global high cloud fraction data from MODIS and cosmic ray of neutron monitor data from McMurdo, Antarctic. We removed 3-month running means from the original data in order to get high frequency fluctuations. As results, positive correlations are dominant in the spatial distribution, especially over lands on the northern hemisphere and oceans on the Southern hemisphere. On the other hand, negative correlations exist over limited area including the Indian Ocean. According to the cross-correlation (with time lags), the areas with positive correlation is widely distributed at zero lag. At ±1 month lags, the signs of correlations become the opposite of that at zero lag. Furthermore, the correlation between relative high cloud amount to total cloud and cosmic ray shows similar distribution to the correlation between absolute high cloud amount and cosmic ray, implying stronger high cloud response to cosmic ray

  15. Calculations of cosmic-ray helium transport in shielding materials

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.

    1993-01-01

    The transport of galactic cosmic-ray helium nuclei and their secondaries through bulk shielding is considered using the straight-ahead approximation to the Boltzmann equation. A data base for nuclear interaction cross sections and secondary particle energy spectra for high-energy light-ion breakup is presented. The importance of the light ions H-2, H-3, and He-3 for cosmic-ray risk estimation is discussed, and the estimates of the fractional contribution to the neutron flux from helium interactions compared with other particle interactions are presented using a 1977 solar minimum cosmic-ray spectrum.

  16. Latest AMS Results on elementary particles in cosmic rays

    NASA Astrophysics Data System (ADS)

    Kounine, Andrei; AMS Collaboration

    2017-01-01

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

  17. 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.

  18. Observations of cosmic gamma ray bursts with WATCH on EURECA

    NASA Astrophysics Data System (ADS)

    Brandt, S.; Lund, N.; Castro-Tirado, A. J.

    19 Cosmic Gamma-Ray Bursts were detected by the Wide Angle Telescope for Cosmic Hard X-rays (WATCH) instruments during the 11 months flight of the European Retrievable Carrier (EURECA). The identification of the bursts was complicated by a high frequency of background of events caused by a high energy cosmic ray interactions in the detector and by low energy, trapped particle streams. These background events may simulate the count rate increases characteristic of cosmic gamma bursts. For 12 of the detected events, their true cosmic nature have been confirmed through consistent localizations of the burst sources based on several independent WATCH data sets. The derived positions of the bursts are reported. Additionally, most of the events have been confirmed by coincident detections with instruments on other spacecraft. The features of two of the bursts and the results of searches for related events in the optical are described.

  19. 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.

  20. Gamma-ray emitting supernova remnants as the origin of Galactic cosmic rays?

    NASA Astrophysics Data System (ADS)

    Becker Tjus, Julia; Eichmann, Björn; Kroll, Mike; Nierstenhöfer, Nils

    2016-08-01

    The origin of cosmic rays is one of the long-standing mysteries in physics and astrophysics. Simple arguments suggest that a scenario of supernova remnants (SNRs) in the Milky Way as the dominant sources for the cosmic ray population below the knee could work: a generic calculation indicates that these objects can provide the energy budget necessary to explain the observed flux of cosmic rays. However, this argument is based on the assumption that all sources behave in the same way, i.e. they all have the same energy budget, spectral behavior and maximum energy. In this paper, we investigate if a realistic population of SNRs is capable of producing the cosmic ray flux as it is observed below the knee. We use 21 SNRs that are well-studied from radio wavelengths up to gamma-ray energies and derive cosmic ray spectra under the assumption of hadronic emission. The cosmic ray spectra show a large variety in their energy budget, spectral behavior and maximum energy. These sources are assumed to be representative for the total class of SNRs, where we assume that about 100-200 cosmic ray emitting SNRs should be present today. Finally, we use these source spectra to simulate the cosmic ray transport from individual SNRs in the Galaxy with the GALPROP code for cosmic ray propagation. We find that the cosmic ray budget can be matched well for these sources. We conclude that gamma-ray emitting SNRs can be a representative sample of cosmic ray emitting sources. In the future, experiments like CTA and HAWC will help to distinguish hadronic from leptonic sources and to further constrain the maximum energy of the sources and contribute to producing a fully representative sample in order to further investigate the possibility of SNRs being the dominant sources of cosmic rays up to the knee.

  1. 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.

  2. Analysis of North Sky Cosmic Ray Anisotropy with Atmospheric Neutrinos

    NASA Astrophysics Data System (ADS)

    Wills, Elizabeth; IceCube Collaboration

    2017-01-01

    Since the discovery of Cosmic Ray anisotropy, no experiment has definitively discovered the source of this unexpected phenomenon. Studying the cosmic rays' neutral daughter particles with pointing capabilities, like neutrinos, could shed new light. This can be done at two levels; a source which produces cosmic rays must also produce high energy astrophysical neutrinos, and low energy atmospheric neutrinos are made when the cosmic rays interact with the atmosphere. This analysis focuses on atmospheric neutrinos detected by IceCube, a Cherenkov detector instrumenting a kilometer cubed of glacial ice at the South Pole. The anisotropy and its energy dependence have been studied in the Southern sky using atmospheric muons by IceCube. In the North, gamma ray detectors, such as HAWC, and Argo-YBJ, have observed this anisotropy in cosmic ray showers. Thus far, no single- detector full-sky map exists of the anisotropy. Using IceCube's neutrino data, we can complement these studies with an exploration of the northern sky anisotropy at higher energies of cosmic rays. This could bring us much closer to understanding the complete picture of this anisotropy across energy levels and the whole sky.

  3. Cosmic ray physics with the ARGO-YBJ experiment

    NASA Astrophysics Data System (ADS)

    Surdo, A.; ARGO-YBJ Collaboration

    2011-04-01

    The main scientific goals of the ARGO-YBJ experiment are γ-ray astronomy with a few hundreds GeV energy threshold and cosmic ray physics below and around the knee of the primary energy spectrum (1012-1016 eV), where the transition from direct to indirect measurement techniques takes place. The ARGO-YBJ experiment, located at the Cosmic Ray Observatory of Yangbajing (Tibet, P.R. of China, 4 300 m a.s.l.), is an unconventional Extensive Air Shower array of about 6,700 m2 of active area, the only one exploiting the full-coverage technique at very high altitude currently in operation. The detector space-time granularity, performance and location offer a unique chance to make a detailed study of the structure of cosmic ray showers, in particular of the hadronic component. In this work we will focus on the main experimental results concerning cosmic ray and hadronic interaction physics: primary cosmic ray energy spectrum, antiproton over proton ratio, anisotropy in the cosmic ray flux and proton-air cross-section. Moreover, the possible data analysis improvements based on the use of all detailed information on the shower front (curvature, time width, rise time, ..), as well as the extension of the investigable energy range, allowed by the analog RPC readout, will be pointed out.

  4. Measurement of cosmic rays with LOFAR

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

    The LOw Frequency ARay (LOFAR) is a multipurpose radio-antenna array aimed to detect radio signals in the 10 - 240 MHz frequency range, covering a large surface in Northern Europe with a higher density in the Northern Netherlands. Radio emission in the atmosphere is produced by cosmic-ray induced air showers through the interaction of charged particles with the Earth magnetic field. The detection of radio signals allows to reconstruct several properties of the observed cascade. We review here all important results achieved in the last years. We proved that the radio-signal distribution at ground level is described by a two-dimensional pattern, which is well fitted by a double Gaussian function. The radio-signal arrival time and polarization have been measured, thus providing additional information on the extensive air shower geometry, and on the radio emission processes. We also showed that the radio signal reaches ground in a thin, curved wavefront which is best parametrized by a hyperboloid shape centred around the shower axis. Radio emission has also been studied under thunderstorm conditions and compared to fair weather conditions. Moreover, by using a hybrid reconstruction technique, we performed mass composition measurements in the energy range 1017 - 1018 eV.

  5. Cosmic ray propagation in interplanetary space

    NASA Technical Reports Server (NTRS)

    Voelk, H. J.

    1975-01-01

    The validity of the test-particle picture, the approximation of static fields, and the spatial-diffusion approximation are discussed in a general way before specific technical assumptions are introduced. It is argued that the spatial-diffusion equation for the intensity per unit energy has a much wider range of applicability than the kinetic (Fokker-Planck) equation it is derived from. This gives strong weight to the phenomenological propagation theory. The general success (and possible failure at small energies) of the phenomenological theory for the modulation of galactic cosmic rays and solar events is described. Apparent effects such as the 'free boundary' are given disproportionate weight since they establish the connection with the detailed plasma physics of the solar wind. Greatest attention is paid to the pitch-angle diffusion theory. A general theory is presented which removes the well-known secularities of the quasi-linear approximation. The possible breakdown of any pitch-angle diffusion theory at very small energies is perhaps connected with the observed 'turn up' of the spectrum at low energies. A first attempt to derive the spatial dependence of the diffusion coefficient in the solar cavity, using such a divergence free scattering theory, is described and compared with recent observations out to 5 AU.

  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. 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.

  8. Gamma ray bursts from superconducting cosmic strings

    NASA Astrophysics Data System (ADS)

    Berezinsky, V.; Hnatyk, B.; Vilenkin, A.

    2001-08-01

    Cusps of superconducting strings can serve as GRB engines. A powerful beamed pulse of electromagnetic radiation from a cusp produces a jet of accelerated particles, whose propagation is terminated by the shock responsible for GRB. A single free parameter, the string scale of symmetry breaking η~1014 GeV, together with reasonable assumptions about the magnitude of cosmic magnetic fields and the fraction of volume that they occupy, explains the GRB rate, duration, and fluence, as well as the observed ranges of these quantities. The wiggles on the string can drive the short-time structures of GRB. This model predicts that GRBs are accompanied by strong bursts of gravitational radiation which should be detectable by LIGO, VIRGO, and LISA detectors. Another prediction is the diffuse x- and gamma-ray radiation at 8 MeV-100 GeV with a spectrum and flux comparable to the observed. The weakness of the model is the prediction of too low a rate of GRBs from galaxies, as compared with observations. This suggests that either the capture rate of string loops by galaxies is underestimated in our model or that GRBs from cusps are responsible for only a subset of the observed GRBs not associated with galaxies.

  9. Cosmic ray spectrum from diffusive shock acceleration

    NASA Astrophysics Data System (ADS)

    Kang, Hyesung; Ryu, Dongsu

    2011-11-01

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

  10. The Pamela Cosmic Ray Space Observatory

    NASA Astrophysics Data System (ADS)

    Casolino, Marco

    2013-09-01

    PAMELA is a satellite borne experiment designed to study with great accuracy cosmic rays of galactic, solar, and trapped nature in a wide energy range (protons: 80 MeV-700 GeV, electrons 50 MeV-400 GeV). Main objective is the study of the antimatter component: antiprotons (80 MeV-190 GeV), positrons (50 MeV-270 GeV) and search for antimatter with a precision of the order of 10-8). The experiment, housed on board the Russian Resurs-DK1 satellite, was launched on June, 15 2006 in a 350 × 600 km orbit with an inclination of 70 degrees. The detector is composed of a series of scintillator counters arranged at the extremities of a permanent magnet spectrometer to provide charge, Time-of-Flight and rigidity information. Lepton/hadron identification is performed by a Silicon-Tungsten calorimeter and a Neutron detector placed at the bottom of the device. An Anticounter system is used offline to reject false triggers coming from the satellite. In self-trigger mode the Calorimeter, the neutron detector and a shower tail catcher are capable of an independent measure of the lepton component up to 2 TeV. In this work we present some of its scientific results in its first five years of operation.

  11. Applications of Cosmic Ray Muon Radiography

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  12. Cosmic ray sources, acceleration and propagation

    NASA Technical Reports Server (NTRS)

    Ptuskin, V. S.

    1986-01-01

    A review is given of selected papers on the theory of cosmic ray (CR) propagation and acceleration. The high isotropy and a comparatively large age of galactic CR are explained by the effective interaction of relativistic particles with random and regular electromagnetic fields in interstellar medium. The kinetic theory of CR propagation in the Galaxy is formulated similarly to the elaborate theory of CR propagation in heliosphere. The substantial difference between these theories is explained by the necessity to take into account in some cases the collective effects due to a rather high density of relativisitc particles. In particular, the kinetic CR stream instability and the hydrodynamic Parker instability is studied. The interaction of relativistic particles with an ensemble of given weak random magnetic fields is calculated by perturbation theory. The theory of CR transfer is considered to be basically completed for this case. The main problem consists in poor information about the structure of the regular and the random galactic magnetic fields. An account is given of CR transfer in a turbulent medium.

  13. Comments on cosmic ray research in Brazil

    NASA Astrophysics Data System (ADS)

    da Silveira, Enio F.

    2013-05-01

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

  14. 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.

  15. Solar Cosmic Ray Acceleration and Propagation

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

    The GOES data for emission of flare protons with the energies of 10 - 100 MeV are analyzed. Proton fluxes of ~1032 accelerated particles take place at the current sheet decay. Proton acceleration in a flare occurs along a singular line of the current sheet by the Lorentz electric field, as in the pinch gas discharge. The duration of proton flux measured on the Earth orbit is by 2 - 3 orders of magnitude longer than the duration of flares. The high energy proton flux from the flares that appear on the western part of the solar disk arrives to Earth with the time of flight. These particles propagate along magnetic lines of the Archimedes spiral connecting the flare with the Earth. Protons from the flare on the eastern part of the solar disk begin to register with a delay of several hours. Such particles cannot get on the magnetic field line connecting the flare with the Earth. These protons reach the Earth, moving across the interplanetary magnetic field. The particles captured by the magnetic field in the solar wind are transported with solar wind and due to diffusion across the magnetic field. The patterns of solar cosmic rays generation demonstrated in this paper are not always observed in the small ('1 cm-2 s-1 ster-1) proton events.

  16. Cosmic Rays for High School Students

    NASA Astrophysics Data System (ADS)

    Bardeen, Marjorie; Peterson, Robert; Jordan, Thomas

    2012-03-01

    We discuss a suite of QuarkNet activities that provide data from the Fermilab cosmic ray DAQ for three learning modes: survey, exploration and investigation. Teachers and students assemble our classroom detectors. They study data locally and/or upload data to a server for others; students without detectors have access to the data. In survey mode, students may sum columns, draw plots comparing columns, calculate descriptive statistics. They can describe patterns and may indicate outliers. Exploration mode provides visual or tabular data for doing measurements that couple values in different columns for a newly derived measurement. Students still draw plots, calculate statistics and describe patterns. Students may attend a master class performing these tasks in a group setting. Students in investigation mode use data and provided analysis and investigation tools to perform research-type investigations. Students can investigate relationships between measurements extant in the data as well as relationships between the presented data and external data sets. They also may perform the same tasks that they do in other modes e.g., draw plots. Students use a project map associated with a browser-based e-Lab to guide their investigations.

  17. Cosmic ray measurements around the knee

    NASA Astrophysics Data System (ADS)

    Chiavassa, Andrea

    2016-07-01

    Primary cosmic rays of energy greater than ˜ 1014 eV must be studied by indirect experiments measuring the particles generated in the EAS (Extensive Air Shower) development in atmosphere. These experiments are mainly limited by the systematic errors due to their energy calibration. I will discuss the main sources of these errors: the choice of the hadronic interaction model and of the mass of the primary particle (that cannot be measured on a event by event basis). I will then summarize some recent measurements of the all particle spectrum, and I will show that, keeping into account the differences due to the energy calibration, they all agree on the spectral shape. Then I will describe the measurements of the light and heavy primaries mass groups spectra, discussing the claimed features. Using a simple calculation of the elemental spectra (based on the hypothesis that the knee energies follow a Peter's cycle) I will try to discuss if all these results can be interpreted in a common picture.

  18. Development of cosmic ray simulation program: Earth cosmic ray shower (ECRS)

    NASA Astrophysics Data System (ADS)

    Hakmana Witharana, Sampath

    ECRS is a program for the detailed simulation of extensive air shower initiated by high energy cosmic ray particles. In this dissertation work, a Geant4 based ECRS simulation was designed and developed to study secondary cosmic ray particle showers in the full range of Earth's atmosphere. A proper atmospheric air density and geomagnetic field are implemented in order to correctly simulate the charged particles interactions in the Earth's atmosphere. The initial simulation was done for the Atlanta (33.46° N , 84.25° W) region. Four different types of primary proton energies (10^9 , 10^10 , 10^11 and 10 12 eV) were considered to determine the secondary particle distribution at the Earth's surface. The geomagnetic field and atmospheric air density have considerable effects on the muon particle distribution at the Earth's surface. The muon charge ratio at the Earth's surface was studied with ECRS simulation for two different geomagnetic locations: Atlanta, Georgia, USA and Lynn Lake, Manitoba, Canada. The simulation results are shown in excellent agreement with the data from NMSU-WIZARD/CAPRICE and BESS experiments at Lynn Lake. At low momentum, ground level muon charge ratios show latitude dependent geomagnetic effects for both Atlanta and Lynn Lake from the simulation. The simulated charge ratio is 1.20 ± 0.05 (without geomagnetic field), 1.12 ± 0.05 (with geomagnetic field) for Atlanta and 1.22 ± 0.04 (with geomagnetic field) for Lynn Lake. These types of studies are very important for analyzing secondary cosmic ray muon flux distribution at the Earth's surface and can be used to study the atmospheric neutrino oscillations.

  19. Cosmic Rays in the Gamma-ray Sky

    NASA Astrophysics Data System (ADS)

    Brandt, T. J.

    2016-03-01

    Instruments directly measuring properties of cosmic rays (CRs) have given us insight into their origins, acceleration mechanisms, and propagation. Indirect measurements provide complementary information which can help disentangle particle types and energetics at sources such as supernova remnants (SNRs), can suggest new sources, and can trace the propagation of CRs through, for instance, interactions with a galaxy's interstellar medium. Gamma rays are particularly good at indirectly illuminating CRs as they are sensitive to the pion decay channel (CR+p+ -->π0 --> γ + γ). Recent work, e.g., using the pion turn-on energy to show proton acceleration in 3 SNRs and mapping CR interactions with Galactic gas using Fermi-LAT, bears this out. The survey capability of instruments like Fermi and HAWC nicely complements the isotropized CRs measured near Earth while VERITAS, MAGIC, and HESS Imaging Air Cherenkov Telescopes (IACTs) provide greater insight into potential sources, including constraining maximum energy both within and beyond our Galaxy. Upcoming IACTs like CTA will greatly enhance this. This talk will explore recent results and potential future insights into CRs using gamma-ray emission and touch on direct measurements made with gamma-ray instruments. This work was supported in part by the Fermi-LAT Collaboration.

  20. 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.

  1. COSMIC-RAY POSITRONS FROM MILLISECOND PULSARS

    SciTech Connect

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

    2015-07-10

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

  2. 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.

  3. 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.

  4. 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)

  5. Plans for Extreme Energy Cosmic Ray Observations from Space

    NASA Technical Reports Server (NTRS)

    Adams, James H., Jr.

    2004-01-01

    Cosmic rays have been detected at energies beyond 10(exp 20) eV, where Universe is predicted to become opaque to protons. The acceleration of cosmic rays to such extreme energies in known astrophysical objects has also proven difficult to understand, leading to many suggestions that new physics may be required to explain their existence. This has prompted the construction of new experiments designed to detect cosmic rays with fluxes below 1 particle/km/century and follow their spectrum to even higher energies. To detect large numbers of these particles, the next generation of these experiments must be performed on space-based platforms that look on very large detection volumes in the Earth's atmosphere. The talk will review the experimental and theoretical investigations of extreme energy cosmic rays and discuss the present and planned experiments to extend measurements beyond 10(exp 21) eV.

  6. 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.

  7. 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.

  8. Cosmic ray synthesis of organic molecules in Titan's atmosphere

    SciTech Connect

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

    1980-01-01

    The possible synthesis of organic molecules by the absorption of galactic cosmic rays in an N2-CH4-H2 Titan model atmosphere has been studied. The cosmic-ray-induced ionization results in peak electron densities of 2000/cu cm, with NH(+), C3H9(+), and C4H9(+) being among the important positive ions. Details of the ion and neutral chemistry relevant to the production of organic molecules are discussed. The potential importance of N(2D) reactions with CH4 and H2 is also demonstrated. Although the integrated production rate of organic matter due to the absorption of the cosmic ray cascade is much less than that by solar ultraviolet radiation, the production of nitrogen-bearing organic molecules by cosmic rays may be greater.

  9. 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.

  10. Solar modulation of galactic cosmic rays: Contemporary observations and theories

    NASA Technical Reports Server (NTRS)

    Forman, M. A.

    1986-01-01

    The flux of galactic cosmic rays inside the solar system is modulated by the action of the complex magnetic fields carried from the Sun by the solar wind. This is apparent from the recurrent decrease of about 20% in the intensity of relativistic cosmic rays during sunspot maximum compared to sunspot minimum, from transient decreases due to solar flares and many other more subtle effects observed by ground stations for the last 50 years. Spacecraft observations of the spatial and temporal variations of cosmic ray flux during the last ten years have shown that the solar wind and cosmic-ray modulation extend to at least 30 astronomical units in the ecliptic plane. Present best guesses are that it goes out to 100 or 200 AU, perhaps less over the poles. Theories describing the mechanism of solar modulation are outlined and the importance of having a firm understanding of this mechanism to the study of other astrophysical phenomena is discussed.

  11. 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.

  12. 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.

  13. Cosmic Ray Background Analysis for MuLAN

    NASA Astrophysics Data System (ADS)

    Mangialardi, Michael

    2008-10-01

    The goal of the MuLAN experiment is to make a measurement of the muon lifetime to a precision of 1 ppm so that a 5 ppm value of the Fermi coupling constant can be calculated. To do this, a beam of positive muons is stopped in a target surrounded by 340 scintillating detectors arranged in a geodesic around the target. Once the muons stop in the target, they decay, and the product positrons are emitted outward, where they are detected by the scintillators. By examining the spectrum of decay times, the lifetime of positive muons can be calculated. One of the myriad factors affecting this measurement is the background of cosmic ray muons constantly showering upon the detector. To study this background, an angular distribution of the cosmic rays was found, and the rate at which cosmic rays muons ``rain'' upon the detector was calculated. In addition, the cosmic rays were used to examine the timing differences between the individual scintillators.

  14. 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)

  15. Cosmic Rays - A Word-Wide Student Laboratory

    NASA Astrophysics Data System (ADS)

    Adams, Mark

    2017-01-01

    The QuarkNet program has distributed hundreds of cosmic ray detectors for use in high schools and research facilities throughout the world over the last decade. Data collected by those students has been uploaded to a central server where web-based analysis tools enable users to characterize and to analyze everyone's cosmic ray data. Since muons rain down on everyone in the world, all students can participate in this free, high energy particle environment. Through self-directed inquiry students have designed their own experiments: exploring cosmic ray rates and air shower structure; and using muons to measure their speed, time dilation, lifetime, and affects on biological systems. We also plan to expand our annual International Muon Week project to create a large student-led collaboration where similar cosmic ray measurements are performed simultaneously throughout the world.

  16. Cosmic ray scintillations. II - General theory of interplanetary scintillations

    NASA Technical Reports Server (NTRS)

    Owens, A. J.

    1974-01-01

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

  17. 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.

  18. 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.

  19. On wave stability in relativistic cosmic-ray hydrodynamics

    NASA Technical Reports Server (NTRS)

    Webb, G. M.

    1989-01-01

    Wave stability of a two-fluid hydrodynamical model describing the acceleration of cosmic rays by the first-order Fermi mechanism in relativistic, cosmic-ray-modified shocks is investigated. For a uniform background state, the short- and long-wavelength wave speeds are shown to interlace, thus assuring wave stability in this case. A JWKB analysis is performed to investigate the stability of short-wavelength thermal gas sound waves in the smooth, decelerating supersonic flow upstream of a relativistic, cosmic-ray-modified shock. The stability of the waves is assessed both in terms of the fluid velocity and density perturbations, as well as in terms of the wave action. The stability and interaction of the short-wavelength cosmic-ray coherent mode with the background flow is also studied.

  20. 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.