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Galactic cosmic-ray energy spectra and composition during the 2009-2010 solar minimum period
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Wiedenbeck, Mark E. Davis, A. J. Binns, W. R. deNolfo, G. A. Israel, M. H. Leske, R. A. Stone, E. C. Mewaldt, R. A. Christian, E. R. Lave, K. A. VonRosenvinge, T. T. Cummings, A. C. |
| Copyright Year | 2013 |
| Description | We report new measurements of the elemental energy spectra and composition of galactic cosmic rays during the 2009-2010 solar minimum period using observations from the Cosmic Ray Isotope Spectrometer (CRIS) onboard the Advanced Composition Explorer. This period of time exhibited record-setting cosmic-ray intensities and very low levels of solar activity. Results are given for particles with nuclear charge 5 <= Z <= 28 in the energy range approx. 50-550 MeV / nucleon. Several recent improvements have been made to the earlier CRIS data analysis, and therefore updates of our previous observations for the 1997-1998 solar minimum and 2001-2003 solar maximum are also given here. For most species, the reported intensities changed by less than approx. 7%, and the relative abundances changed by less than approx. 4%. Compared with the 1997-1998 solar minimum relative abundances, the 2009-2010 abundances differ by less than 2sigma, with a trend of fewer secondary species observed in the more recent time period. The new 2009-2010 data are also compared with results of a simple "leaky-box" galactic transport model combined with a spherically symmetric solar modulation model. We demonstrate that this model is able to give reasonable fits to the energy spectra and the secondary-to-primary ratios B/C and (Sc+Ti+V)/Fe. These results are also shown to be comparable to a GALPROP numerical model that includes the effects of diffusive reacceleration in the interstellar medium. |
| File Size | 327638 |
| Page Count | 16 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20140010417 |
| Archival Resource Key | ark:/13960/t1xd5wh5c |
| Language | English |
| Publisher Date | 2013-06-03 |
| Access Restriction | Open |
| Subject Keyword | Galactic Cosmic Rays Gcr Energy Spectra Gcr Composition Advanced Composition Explorer Energy Spectra Astronomical Models Solar Activity Effects Mathematical Models Solar Cycles Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
