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Cosmic-ray helium intensities over the solar cycle from ACE

de Nolfo, G. A. and Binns, W. R. and Cohen, C. M. S. and Cummings, A. C. and Davis, A. J. and George, J. S. and Hink, P. L. and Israel, M. H. and Lave, K. and Leske, R. A. and Mewaldt, R. A. and Moskalenko, I. V. and Ogliore, R. C. and Stone, E. C. and von Rosenvinge, T. T. and Wiedenbeck, M. E. and Yanasak, N. E. (2007) Cosmic-ray helium intensities over the solar cycle from ACE. In: Proceedings of the 30th International Cosmic Ray Conference. Vol.1. Universidad Nacional Autónoma de México , Merida, Yucatan, Mexico, pp. 813-816.

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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 ∼10 to ∼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.

Item Type:Book Section
Related URLs:
URLURL TypeDescription
de Nolfo, G. A.0000-0002-3677-074X
Binns, W. R.0000-0001-6110-3407
Cohen, C. M. S.0000-0002-0978-8127
Cummings, A. C.0000-0002-3840-7696
Israel, M. H.0000-0002-8104-208X
Leske, R. A.0000-0002-0156-2414
Mewaldt, R. A.0000-0003-2178-9111
Stone, E. C.0000-0002-2010-5462
Wiedenbeck, M. E.0000-0002-2825-3128
Additional Information:Copyright Universidad Nacional Autónoma de México This work was supported by NASA at GSFC, Caltech, JPL, and Washington University in St. Louis.
Group:Space Radiation Laboratory
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Space Radiation Laboratory2008-06
Record Number:CaltechAUTHORS:20150413-154918541
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:56617
Deposited By: Deborah Miles
Deposited On:21 Apr 2015 20:27
Last Modified:09 Mar 2020 13:19

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