Research in particles and fields

Research activities in Cosmic Rays, Gamma Rays, and Astrophysical Plasmas supported under NASA Grant NGR 05-002-160 are discussed. The report is divided into sections which describe the activities, followed by a bibliography. This group's research program is directed toward the investigation of the astrophysical aspects of cosmic rays and gamma rays and of the radiation and electromagnetic field environment of the Earth and other planets. These investigations are carried out by means of energetic particle and photon detector systems flown on spacecraft and balloons

Research in cosmic and gamma ray astrophysics

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

Model for Cumulative Solar Heavy Ion Energy and Linear Energy Transfer Spectra

A probabilistic model of cumulative solar heavy ion energy and LET spectra is developed for spacecraft design applications. Spectra are given as a function of confidence level, mission time period during solar maximum and shielding thickness. It is shown that long-term solar heavy ion fluxes exceed galactic cosmic ray fluxes during solar maximum for shielding levels of interest. Cumulative solar heavy ion fluences should therefore be accounted for in single event effects rate calculations and in the planning of space missions

Research in particles and fields

The astrophysical aspects of cosmic rays and gamma rays and the radiation and electromagnetic field environment of the Earth and other planets are investigated. These investigations are carried out by means of energetic particle and photon detector systems flown on spacecraft and balloons. Particle astrophysics is directed toward the investigation of galactic, solar, interplanetary, and planetary energetic particles and plasmas. The emphasis is on precision measurements with high resolution in charge, mass, and energy. Gamma ray research is directed toward the investigation of galactic, extragalactic, and solar gamma rays with spectrometers of high angular resolution and moderate energy resolution carried on spacecraft and balloons

Research in particles and fields

Research activities in Cosmic Rays Gamma Rays, and Astrophysical Plasmas are covered The investigation of the astrophysical aspects of cosmic rays and gamma rays and of the radiation and electromagnetic field environment of the Earth and other planets are studied. These investigations are carried ut by means of energetic particle and photon detector systems flown on spacecraft and balloons. The emphasis is on precision measurements with high resolution in charge mass and energy. An extensive bibliography is given

Research in particle and gamma-ray astrophysics

Research activities in cosmic rays, gamma rays, and astrophysical plasmas are covered. Each activity is described, followed by a bibliography. The research program is directed toward the investigation of the astrophysical aspects of cosmic rays and gamma rays and of the radiation and electromagnetic field environment of the earth and other planets. These investigations were performed by means of energetic particle and photon detector systems flown on spacecraft and balloons

Research in particles and fields

Discussed are the research activities in Cosmic Rays, Gamma Rays, and Astrophysical Plasmas supported under NASA Grant NGR 05-002-160. The report is divided into sections which describe the activities, followed by a bibliography. This research program is directed toward the investigation of the astrophysical aspects of cosmic rays and gamma rays and of the radiation and electromagnetic field environment of the Earth and other planets. These investigations are carried out by means of energetic particle and photon detector systems flown on spacecraft and balloons

UHCR: A Cosmic Ray Mission to Study Nuclei in the Charge Range From 20 ≤Z ≤100

A definitive study of the elemental abundances of nuclei over the charge range of 20 ≤ Z ≤ 100 requires a satellite mission capable of obtaining high statistics and excellent charge resolution over the full charge range. Such a mission, utilizing an electronic instrument which is an evolution of the HEA0-3 Heavy Nuclei Experiment, is described here

A novel technique to infer ionic charge states of solar energetic particles

In some large solar energetic particle (SEP) events, the intensities of higher energy SEPs decay more rapidly than at lower energies. This energy dependence varies with particle species, as would be expected if the decay timescale depended on a rigidity-dependent diffusion mean free path. By comparing the decay timescales of carbon, nitrogen, oxygen, neon, magnesium, silicon, sulfur, and iron, mean charge states are inferred for these (and other) elements in three SEP events between 1997 and 2002 at energies between 10 and 200 MeV nucleon−1. In a fourth event, upper limits for the charge states are inferred. The charge states of many different particle species are all consistent with a single source temperature; in two events in 1997 and 2002, the best-fit temperature is much higher than that of the corona, which could imply a contribution from solar flare material. However, comparison with lower energy iron charge states for the 1997 event implies that the observed high-energy charge state could also be understood as the result of stripping during shock acceleration in the corona