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Measurements of the gamma-ray emission in the medium-energy range between 15 and 100 MeV, obtained during two balloon flights from Brazil, are presented. The importance of this energy region in determining whether neutral-pion decay or electron bremsstrahlung is the most likely dominant source mechanism is discussed, along with the implications of such observations. Specifically, the data from this experiment suggest that emission from the galactic plane is similar to the theoretical spectrum calculated by Fichtel et al. (1976), including both source mechanisms but with the bremsstrahlung component enhanced by a factor of about 2. A spectral distribution of gamma-rays produced in the residual atmosphere above the instrument is also presented and compared with other data. A rather smooth spectral variation from high to low energies is found for the atmospheric spectrum.

A balloon-borne magnetic core digitized spark chamber with two assemblies of spark-chambers above and below the scintillation counters was used to measure the medium energy gamma ray flux from the galactic center region. Gamma ray calculations are based on the multiple scattering of the pair electrons in 15 aluminum plates interleaved in the spark chamber modules. Counting rates determined during ascent and at ceiling indicate the presence of diffuse component in this energy range. Preliminary results give an integral flux between 15 and 70 MeV compared to the differential points in other results.

To observe the medium energy component of the intense galactic center gamma-ray emission, two balloon flights of a medium energy gamma-ray spark chamber telescope were flown in Brazil in 1975. The results indicate the emission is higher than previously thought and above the predictions of a theoretical model proposed.

Solar low energy cosmic ray population anisotropy from satellite observations during flare event, describing rise time, decay, field alignment and time constant

Anisotropy of solar cosmic ray electrons, considering parallel diffusion coefficients for ions and electrons

Satellite-borne anisotropy and energy spectra measurement instruments for cosmic ray electrons and protons and solar and galactic X-rays

Satellite cosmic ray monitors data, examining corotation with sun to obtain interplanetary magnetic field spatial structure

Solar flare event of 28 January 1967, observing parent flare location, particle fluxes and diffusion and spectral exponent

High energy solar flare data from neutron monitor stations supplemented by low energy data from interplanetary space probes Pioneer 6 and 7

Cosmic ray increases during Forbush decrease onset stage in terms of transient spatial anisotropy

Statistical correlation of rotating cosmic ray fluxes observed by separated spacecrafts in solar azimuth

Solar cosmic ray anisotropy measurement by Explorer 34 satellite during solar flare events

Filamentary interplanetary magnetic field structure effect on solar flare ground observational data

Electromagnetic radiation due to cosmic ray energy dissipation in interstellar hydrogen

Solar modulation of galactic protons and He nuclei during last solar cycle analyzed according to Parker theory

Solar modulation of galactic protons and helium nuclei - proton to helium nucleus ratio

Low energy spectrum of cosmic rays corrected for solar modulation and diffusive passage through interstellar matter

Low energy spectrum of cosmic rays as indicator of primary source characteristics and interstellar propagation

Cosmic ray intensity variations measured by GM COUNTER telescope onboard Imp I satellite for study of interplanetary medium

IMP-1 cosmic ray detector design and intensity measurements

Solar and galactic cosmic ray characteristics, origin and flux-time variations, examining relation between solar flares and geomagnetic storms

Cosmic ray intensity data from IMP-1 detector

The anisotropy of the particle distribution and its variation with time at 1 AU early in a solar cosmic-ray event can provide information on the pitch-angle scattering of the particles in the interplanetary medium. One proton event (7.6-55 MeV) is described in which the anisotropy remained large well into the decay of the omnidirectional intensity. A Monte Carlo technique which gives the pitch-angle distribution is employed to investigate two models put forward to explain the sustained anisotropy. It is shown that the observed event is consistent with a model in which the injection of particles at the sun reaches a peak 1.5 hours after flare maximum before decaying with an e-folding time of 7 hours. The uniform diffusion coefficient in this model corresponds to a classical mean free path of 1.6 AU.

The detailed relationship between the anisotropy characteristics observed during late times in the decay of a solar flare event and the interplanetary magnetic field parameters is investigated. The anisotropy always is from 45 deg east of the earth-sun line. This direction is approximately perpendicular to the nominal Archimedean spiral, independent of the particle energy. The amplitude of the anisotropy increases as the magnetic field azimuthal direction shows greater departure from the radial direction. These results are discussed in terms of current ideas about solar particle propagation in the interplanetary space.

The detector and data reduction techniques used in connection with the cosmic ray experiments designed for and flown on Explorer 34 and 41 satellites are described. A history of the program development and the present status of data processing are briefly summarized. The instrument to measure the anisotropy and energy spectra of cosmic ray electrons and protons, and X-rays of solar and galactic origin is discussed. The main characteristics of the detectors and the stability during 23 months of operation are described. The method of analysis of the angular distribution of solar cosmic ray particles in the ecliptic plane is given. It is shown that the anisotropy of low energy particles of solar origin decreases sharply to a very small value when the satellite penetrates the magnetosphere.