کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1766520 | 1020152 | 2008 | 5 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
The role of radial perpendicular diffusion and latitude dependent acceleration along the solar wind termination shock
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
علوم فضا و نجوم
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چکیده انگلیسی
A numerical model, based on Parker's transport equation, describing the modulation of anomalous cosmic rays and containing diffusive shock acceleration is applied. The role of radial perpendicular diffusion at the solar wind termination shock, and as the dominant diffusion coefficient in the outer heliosphere, is studied, in particular the role it plays in the effectiveness of the acceleration of anomalous protons and helium when its latitude dependence is changed. It is found that the latitudinal enhancement of radial perpendicular diffusion towards the heliospheric poles and along the termination shock has a prominent effect on the acceleration of these particles. It results in a 'break' in the energy spectrum for anomalous protons at â¼6.0Â MeV, causing the spectral index to change from Eâ1.38 to Eâ2.23, but for anomalous helium at â¼3.0Â MeV, changing the spectral index from Eâ1.38 to Eâ2.30. When approaching the simulated TS, the changes in the modulated spectra as they unfold to a 'steady' power law shape at energies below 50Â MeV are much less prominent as a function of radial distances when radial perpendicular diffusion is increased with heliolatitude.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Advances in Space Research - Volume 41, Issue 2, 2008, Pages 368-372
Journal: Advances in Space Research - Volume 41, Issue 2, 2008, Pages 368-372
نویسندگان
U.W. Langner, M.S. Potgieter,