دانلود گزارش کارورزی و کار آموزی

چکیده : 

The Wind spacecraft’s Faraday cups (FC) continue to produce high-quality, in situ observations of thermal protons (i.e., ionized

hydrogen) and a-particles (i.e., fully ionized helium) in the solar wind. By fitting a Wind/FC ion spectrum with a model velocity distribution

function (VDF) for each particle species, values for density, bulk velocity, and temperature can be inferred. Incorporating measurements

of the background magnetic field from the Wind Magnetic Field Investigation (MFI) allows perpendicular and parallel

temperature components to be separated. Prior implementations of this analysis averaged the higher-cadence Wind/MFI measurements

to match that of the Wind/FC ion spectra. However, this article summarizes recent and extensive revisions to the analysis software that,

among other things, eliminate such averaging and thereby account for variations in the direction of the magnetic field over the time taken

to measure the ions. A statistical comparison reveals that the old version consistently underestimates the temperature anisotropy of ion

VDF’s: averaging over fluctuations in the magnetic field essentially blurs the perpendicular and parallel temperature components, which

makes the plasma seem artificially more isotropic. The new version not only provides a more accurate dataset of ion parameters (which is

well suited to the study of microkinetic phenomena), it also demonstrates a novel technique for jointly processing particle and field data.

Such methods are crucial to heliophysics as wave-particle interactions are increasingly seen as playing an important role in the dynamics

of the solar wind and similar space plasmas.