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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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NASA NTRS1982

Spacelab mission 2: Experimental descriptions

The second Spacelab Mission and the 12 multidisciplinary experiments selected to fly on board are described. These experiments include the following: vitamin D metabolities and bone demineralization; interaction of oxygen and gravity influenced lignification; ejectable plasma diagnostics package; plasma depletion experiments for ionospheric and radio astronomical studies; small helium cooled IR telescope; elemental composition and energy spectra of cosmic ray nuclei; hard X-ray imaging of clusters of galaxies and other extended X-ray sources; solar magnetic and velocity field measurement system; solar coronal helium abundance Spacelab experiment; solar UV high resolution telescope and spectroraph; solar UV spectral irradiance monitor; and properties of superfluid helium in zero-G.

Clifton, K. S.↗
NASA NTRS1990

Large Isotope Spectrometer for Astromag

The Large Isotope Spectrometer for Astromag (LISA) is an experiment designed to measure the isotopic composition and energy spectra of cosmic rays for elements extending from beryllium through zinc. The overall objectives of this investigation are to study the origin and evolution of galactic matter; the acceleration, transport, and time scales of cosmic rays in the galaxy; and search for heavy antinuclei in the cosmic radiation. To achieve these objectives, the LISA experiment will make the first identifications of individual heavy cosmic ray isotopes in the energy range from about 2.5 to 4 GeV/n where relativistic time dilation effects enhance the abundances of radioactive clocks and where the effects of solar modulation and cross-section variations are minimized. It will extend high resolution measurements of individual element abundances and their energy spectra to energies of nearly 1 TeV/n, and has the potential for discovering heavy anti-nuclei which could not have been formed except in extragalactic sources.

Binns, W. R.↗
NASA NTRS2001

The ATIC Experiment: First Balloon Flight

The Advanced Thin Ionization Calorimeter (ATIC) Balloon Experiment had its maiden, test, flight from McMurdo, Antarctica 28/12/00 to 13/01/01, local time, recording over 360 hours of data. ATIC was designed to measure the composition and energy spectra of cosmic rays from approximately 10 GeV to near 100 TeV utilizing a Si-matrix detector to determine charge in conjunction with a scintillator hodoscope which measures charge and trajectory. Cosmic rays that interact in a Carbon target have their energy determined from the shower that develops within a fully active calorimeter composed of a stack of scintillating BGO crystals. ATIC's geometry factor is about 0.25 m**2-sr. During line-of-sight operations much of the datastream was transmitted to the ground. For most of the flight, the data was recorded on-board, yielding 45 GB of flight data for analysis. The payload construction, operations and in-flight performance are described, along with preliminary results from the on-going analysis.

Wefel, J. P.↗
NASA NTRS2001

The ATIC Experiment: First Balloon Flight

The Advanced Thin Ionization Calorimeter (ATIC) Balloon Experiment had its maiden test flight from McMurdo, Antarctica 28/12/00 to 13/01/01, local time, recording over 360 hours of data. ATIC was designed to measure the composition and energy spectra of cosmic rays from approx. 10 GeV to near 100 TeV utilizing a Si matrix detector to determine charge in conjunction with a scintillator hodoscope which measures charge and trajectory. Cosmic rays that interact in a carbon target have their energy determined from the shower that develops within a fully active calorimeter composed of a stack of scintillating BGO (Bismuth Germanate) crystals. ATIC's geometry factor is about 0.25 sq. m -sr. During line-of-sight operations much of the datastream was transmitted to the ground. For most of the flight, the data was recorded on-board, yielding 45 GB of flight data for analysis. The payload construction, operations and in-flight performance are described, along with preliminary results from the on-going analysis.

Wefel, J. P.↗
NASA NTRS2003

The ATIC Science Flight in 2002-03: Description and Preliminary Results

The Advanced Thin Ionization Calorimeter (ATIC) balloon experiment completed a 19.7 day science flight, 29 Dec. 02 to 18 Jan. 03, from McMurdo, Antarctica, yielding 65 Gbytes of science data. The instrument was fully recovered just over the trans-Antarctic mountain range. ATIC is designed to make new measurements of the composition and energy spectra of cosmic rays in the region up to 100 TeV total energy. The flight and the instrument performance are described and compared to the ATIC-1 flight from 2000-01. Although the data from this new flight will not be fully processed and analyzed, some preliminary results are discussed.

Wefel, J. P.↗
NASA NTRS2004

The Energy Spectra of Proton and Helium Measured from the ATIC Experiment

The Advanced Thin Ionization Calorimeter (ATIC) balloon experiment is designed to investigate the composition and energy spectra of cosmic rays at the highest energies currently accessible from direct measurements, the region up to 100 TeV. The instrument consists of a silicon matrix for charge measurement, a graphite target (0.75 nuclear interaction length) to induce hadronic fragmentation, 3 scintillator strip hodoscopes for triggering and helping reconstruct trajectory, and a BGO calorimeter (18 radiation lengths) to measure the energy of incident particles. ATIC had two successful Long Duration Balloon (LDB) flights from McMurdo, Antarctica: from 12/28/00 to 01/13/01 and from 12/29/02 to 01/18/03. We present the energy spectra of proton and helium extracted from the ATIC flights, over the energy range from 100 GeV to 100 TeV, and compare them with the results from other experiments at both the lower and higher energy ends.

Ahn, H. S.↗
NASA NTRS2007

All-Particle Spectrum Measured by the ATIC Experiment

The Advanced Thin Ionization Calorimeter (ATIC), a balloon-borne experiment, is designed to investigate the composition and energy spectra of cosmic rays of charge Z = 1 to 26 over the energy range - 10(exp 11) - 10(exp 14) ev. The instrument consists of a silicon matrix charge detector, plastic-scintillator strip hodoscopes interleaved with graphite interaction targets, and an 18 radiation length deep, fully active bismuth germanate (BGO) calorimeter. ATIC has had two successful long duration balloon (LDB) flights launched from McMurdo Station, Antarc't'ica in 2000 and 2002. In this paper, we present the all-particle spectrum extracted from data collected during the ATIC flights, and compare it with results from other experiments at both lower and higher energies.

Ahn, H. S.↗
NASA NTRS2011

Ionization Processes in the Atmosphere of Titan (Research Note). III. Ionization by High-Z Nuclei Cosmic Rays

Context. The Cassini-Huygens mission has revealed the importance of particle precipitation in the atmosphere of Titan thanks to in-situ measurements. These ionizing particles (electrons, protons, and cosmic rays) have a strong impact on the chemistry, hence must be modeled. Aims. We revisit our computation of ionization in the atmosphere of Titan by cosmic rays. The high-energy high-mass ions are taken into account to improve the precision of the calculation of the ion production profile. Methods. The Badhwahr and O Neill model for cosmic ray spectrum was adapted for the Titan model. We used the TransTitan model coupled with the Planetocosmics model to compute the ion production by cosmic rays. We compared the results with the NAIRAS/HZETRN ionization model used for the first time for a body that differs from the Earth. Results. The cosmic ray ionization is computed for five groups of cosmic rays, depending on their charge and mass: protons, alpha, Z = 8 (oxygen), Z = 14 (silicon), and Z = 26 (iron) nucleus. Protons and alpha particles ionize mainly at 65 km altitude, while the higher mass nucleons ionize at higher altitudes. Nevertheless, the ionization at higher altitude is insufficient to obscure the impact of Saturn s magnetosphere protons at a 500 km altitude. The ionization rate at the peak (altitude: 65 km, for all the different conditions) lies between 30 and 40/cu cm/s. Conclusions. These new computations show for the first time the importance of high Z cosmic rays on the ionization of the Titan atmosphere. The updated full ionization profile shape does not differ significantly from that found in our previous calculations (Paper I: Gronoff et al. 2009, 506, 955) but undergoes a strong increase in intensity below an altitude of 400 km, especially between 200 and 400 km altitude where alpha and heavier particles (in the cosmic ray spectrum) are responsible for 40% of the ionization. The comparison of several models of ionization and cosmic ray spectra (in intensity and composition) reassures us about the stability of the altitude of the ionization peak (65 km altitude) with respect to the solar activity.

Gronoff, G.↗
NASA NTRS2003

The ATIC Long Duration Balloon Project

Long Duration Balloon (LDB) scientific experiments, launched to circumnavigate the south pole over Antarctica, have particular advantages compared to Shuttle or other Low Earth Orbit (LEO) missions in terms of cost, weight, scientific 'duty factor' and work force development. The Advanced Thin Ionization Calorimeter (ATIC) cosmic ray astrophysics experiment is a good example of a university-based project that takes full advantage of current LDB capability. The ATIC experiment is currently being prepared for its first LDB science flight that will investigate the charge composition and energy spectra of primary cosmic rays over the energy range from about 10(exp 10) to 10(exp 14) eV. The instrument is built around a fully active, Bismuth Germanate (BGO) ionization calorimeter to measure the energy deposited by the cascades formed by particles interacting in a thick carbon target. A highly segmented silicon matrix, located above the target, provides good incident charge resolution plus rejection of the 'backscattered' particles from the interaction. Trajectory reconstruction is based on the cascade profile in the BGO calorimeter, plus information from the three pairs of scintillator hodoscope layers in the target section above it. A full evaluation of the experiment was performed during a test flight occurring between 28 December 2000 and 13 January 2001 where ATIC was carried to an altitude of approx. 37 km above Antarctica by an approx. 850,000 cu m helium filled balloon for one circumnavigation of the continent. All systems behaved well, the detectors performed as expected, more than 43 gigabytes of engineering and cosmic ray event data was returned and these data are now undergoing preliminary data analysis. During the coming 2002-2003 Antarctica summer season, we are preparing for a ATIC science flight with approx. 15 to 30 days of continuous data collection in the near-space environment of LDB float altitudes.

Guzik, T. G.↗
NASA NTRS1988

Toward a descriptive model of galactic cosmic rays in the heliosphere

Researchers review the elements that enter into phenomenological models of the composition, energy spectra, and the spatial and temporal variations of galactic cosmic rays, including the so-called anomalous cosmic ray component. Starting from an existing model, designed to describe the behavior of cosmic rays in the near-Earth environment, researchers suggest possible updates and improvements to this model, and then propose a quantitative approach for extending such a model into other regions of the heliosphere.

Mewaldt, R. A.↗
NASA NTRS1978

Momentum spectra and charge ratio of muons as a function of zenith angles

A detailed calculation of both the sea-level muon momentum spectra and charge ratio at angles up to 79 deg shows excellent agreement with available experimental data in the 1-5000 GeV/c range. It shows that there is no need at present to invoke any change in the cosmic ray chemical composition, the proton and helium spectra, or the nature of the hadronic interaction from what is presently observed at proton energies up to about 1500 GeV. If scaling in the relevant energy range holds for hadrons of energies above about 1500 GeV, the present results suggest that the cosmic ray proton and helium spectrum above 100 GeV continues with the same spectral index of 2.75 up to at least about 10 TeV.

Badhwar, G. D.↗
NASA NTRS1980

The high energy cosmic ray detector for Spacelab II

A large cosmic ray detector to be flown on Spacelab II is presently under construction at the University of Chicago. The instrument, with a geometric factor of 5 sq m-ster, is designed to measure the elemental composition and the energy spectra of individual cosmic ray nuclei (Li to Fe) from 50 GeV/nucleon to several TeV/nucleon. Plastic scintillators are used for charge determination, and gas Cerenkov and transition radiation detectors for energy measurements. The instrument and its functions are described, and several test results that are important for an optimum design are discussed.

Lamport, J. E.↗
NASA NTRS1987

IONS (ANURADHA): Ionization states of low energy cosmic rays

IONS (ANURADHA), the experimental payload designed specifically to determine the ionization states, flux, composition, energy spectra and arrival directions of low energy (10 to 100 MeV/amu) anomalous cosmic ray ions of helium to iron in near-Earth space, had a highly successful flight and operation Spacelab-3 mission. The experiment combines the accuracy of a highly sensitive CR-39 nuclear track detector with active components included in the payload to achieve the experimental objectives. Post-flight analysis of detector calibration pieces placed within the payload indicated no measurable changes in detector response due to its exposure in spacelab environment. Nuclear tracks produced by alpha-particles, oxygen group and Fe ions in low energy anomalous cosmic rays were identified. It is calculated that the main detector has recorded high quality events of about 10,000 alpha-particles and similar number of oxygen group and heavier ions of low energy cosmic rays.

Biswas, S.↗
NASA NTRS1974

Cosmic ray experimental observations

The current experimental situation in cosmic ray studies is discussed, with special emphasis on the development of new detector systems. Topics covered are the techniques for particle identification, energy measurements, gas Cerenkov counters, magnet spectrometers, ionization spectrometers, track detectors, nuclear emulsions, multiparameter analysis using arrays of detectors, the Goddard ionization spectrometer, charge spectra, relative abundances, isotope composition, antinuclei in cosmic rays, electrons, the measurement of cosmic ray arrival directions, and the prehistory of cosmic rays.

Balasubrahmanyan, V. K.↗
NASA NTRS2013

Elemental GCR Observations during the 2009-2010 Solar Minimum Period

Using observations from the Cosmic Ray Isotope Spectrometer (CRIS) onboard the Advanced Composition Explorer (ACE), we present new measurements of the galactic cosmic ray (GCR) elemental composition and energy spectra for the species B through Ni in the energy range approx. 50-550 MeV/nucleon during the record setting 2009-2010 solar minimum period. These data are compared with our observations from the 1997-1998 solar minimum period, when solar modulation in the heliosphere was somewhat higher. For these species, we find that the intensities during the 2009-2010 solar minimum were approx. 20% higher than those in the previous solar minimum, and in fact were the highest GCR intensities recorded during the space age. Relative abundances for these species during the two solar minimum periods differed by small but statistically significant amounts, which are attributed to the combination of spectral shape differences between primary and secondary GCRs in the interstellar medium and differences between the levels of solar modulation in the two solar minima. We also present the secondary-to-primary ratios B/C and (Sc+Ti+V)/Fe for both solar minimum periods, and demonstrate that these ratios are reasonably well fit by a simple "leaky-box" galactic transport model that is combined with a spherically symmetric solar modulation model.

Solar Modulation↗
NASA NTRS1979

Energy Spectra of Cosmic Ray Nuclei to Above 100 Gev/nucleon

The chemical composition cosmic rays as a function of energy in the range of a few GeV/nucleon to some hundreds of GeV/nucleon for boron through iron are presented. The experiment combined an ionization spectrometer and a gas Cherenkov counter, which was flown on a balloon, to perform two different and independent energy measurements. The experimental apparatus is described in detail. The energy dependence of the cosmic ray escape length for boron and iron is reported and predicted changes in the energy dependence of the ratios of primary nuclei 0/C and iron/C+0 are discussed.

Simon, M.↗
NASA NTRS1973

Results on the energy dependence of cosmic ray charge composition

Measurements using a balloon-borne ionization spectrometer on the differential energy spectra of the heavy nuclei of the galactic cosmic radiation are reported. The spectra of individual elements up to oxygen and groups of nuclei up through iron were measured up to almost 100 GeV/nucleon. The energy spectrum of the secondary nuclei, B+N, is steeper than that of the primary nuclei, C+O, by gamma = 0.21 + or - .09 in agreement with other authors. The spectral shapes found are reasonably well represented by single power laws between 2 and 60 GeV/nucleon. Data are consistent with the decrease in the secondary to primary ratio found by others above 20 GeV/nucleon, but it shows no evidence for any sudden change in this ratio within counting statistics. The most dramatic finding is that the spectrum of the iron nuclei is flatter than that of the carbon and oxygen nuclei by 0.57 + or - 0.14 of a power. The experimental techniques for charge and energy determination are presented and corrections due to nuclear disintegration and losses of energy out the bottom of the spectrometer are discussed.

Balasubrahmanyan, V. K.↗
NASA NTRS1978

Charge and energy spectra of heavy cosmic rays at intermediate energies

The energy spectra and the charge composition of the primary elements C, O, Ne, Mg, and Si have been measured in both the low-energy and high-energy modes of the University of Chicago telescope on board the IMP 8 spacecraft. Combining both modes of analysis yields differential energy spectra for each element from about 50 MeV/nucleon to about 1 GeV/nucleon. The charge ratios with respect to oxygen are found to be energy independent over this interval and are consistent with the results of cosmic-ray propagation and solar-modulation calculations. The relative abundances obtained are in substantial agreement with previous investigations in this energy regime.

Garcia-Munoz, M.↗