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| Titel |
Stochastic Heating of Protons in Low-β Fast Solar Wind Streams Near r = 0.3 AU |
| VerfasserIn |
Sofiane Bourouaine, Benjamin D. G. Chandran |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250076363
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| Zusammenfassung |
| We use Helios-2 measurements to investigate whether stochastic heating by low-frequency
AW/KAW turbulence is capable of explaining the perpendicular heating of proton near 0.29
AU. We analyze magnetic-field measurements in low-β fast-solar-wind streams to determine
the rms amplitude of the fluctuating magnetic field, δBÏ, near the proton gyroradius scale Ï.
We then evaluate the stochastic heating rate Q-¥stoch (which is given by a previously
published analytical formula) using the measured value of δBÏ . After the estimation of the
‘empirical’ perpendicular heating rate of proton Q-¥emp near r = 0.29 AU, we find that
Q-¥stoch ~ Q-¥emp, but only if the two dimensionless constants appearing in the
formula for Q-¥stoch lie within a certain range. This range is consistent with the
results of numerical simulations of the stochastic heating of test particles in reduced
magnetohydrodynamic turbulence, consistent with the hypothesis that stochastic heating
accounts for much of the perpendicular proton heating occurring in low-β fast-wind streams
at r ~ 0.3Â AU. |
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