ﻻ يوجد ملخص باللغة العربية
This paper examines the cosmic ray He and C nuclei spectra below ~1 GeV/nuc, as well as the very rapid increase in the He/C ratio below ~100 MeV/nuc, measured by Voyager 1 beyond the heliopause. Using a simple Leaky Box Model (LBM) for galactic propagation we have not been able to simultaneously reproduce the individual He and C nuclei spectra and the large increase in He/C ratio that is observed at low energies. However, using a truncated LBM with different truncation parameters for each nucleus that are related to their rate of energy loss by ionization which is ~Z2/A, these different features can be matched. This suggests that we are observing the effects of the source distribution of cosmic rays in the galaxy on the low energy spectra of cosmic ray nuclei and that there may be a paucity of nearby sources. In this propagation model we start very specific source spectra for He and C which are ~dj/dP = P-2.24, the same for each nucleus and also for all rigidities. These source spectra become spectra with spectral indices ~-2.69 at high rigidities for both charges as a result of a rigidity dependence of the diffusion coefficient governing the propagation which is taken to be ~P-0.45. This exponent is determined directly from the B/C ratio measured by AMS-2. These propagated P-2.69 spectra, when extended to high energies, predict He and C intensities and a He/C ratio that are within +3-5% of the intensities and ratio recently measured by AMS-2 in the energy range from 10 to 1000 GeV/nuc.
After the disappearance of lower energy heliospheric particles at Voyager 1 starting on August 25th, 2012, spectra of H, He and C/O nuclei were revealed that resembled those to be expected for galactic cosmic rays. These spectra had intensity peaks i
This paper describes the unfolding of the solar modulated galactic cosmic ray H and He nuclei spectra beyond ~105 AU in the heliosheath. Between 2008.0 and 2012.3 when Voyager 1 went from about 105 to 120.5 AU the spectral intensities of these two co
This paper determines the relative source spectra of cosmic ray H and He nuclei using a Leaky Box model for galactic propagation and the observed spectra of these nuclei from ~10 MeV/nuc to ~1 TeV/nuc. The observations consist of Voyager 1 measuremen
This paper has not yet been accepted for publication
We have obtained the energy spectra of cosmic ray He, B, C, O, Mg, S and Fe nuclei in the range 0.5-1.5 GeV/nuc and above using the penetrating particle mode of the High Energy Telescope, part of the Cosmic Ray Science (CRS) experiment on Voyagers 1