The Low Energy Charged Particle (LECP) experiment on the Voyager spacecraft

Krimigis, S. M.; Armstrong, T. P.; Axford, W. I.; Bostrom, C. O.; Fan, C. Y.; Gloeckler, G.; Lanzerotti, L. J.

doi:10.1007/bf00211545

Cited by 202 publications

(112 citation statements)

References 17 publications

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“…The Low Energy Charged Particle (LECP) experiments aboard the two Voyager spacecraft [Krimigis et al, 1977] return composition and differential flux measurements of energetic ions (-0.3 to 30 MeV/nucleon) in the distant heliosphere. From the first day of 1998 to the last day of 1999 the helioradii of V 1 and V2 increased from 68.9 to 76.3 AU and from 53.7 to 59.9 AU, respectively.…”

Section: Discussionmentioning

confidence: 99%

Periodicity of 151 days in outer heliospheric anomalous cosmic ray fluxes

Hill¹,

Hamilton²,

Krimigis³

2001

J. Geophys. Res.

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Abstract. Statistically significant variations have been observed in the differential flux of--27-MeV anomalous cosmic ray (ACR) oxygen, helium, and protons at the Voyager 1 spacecraft during 1998 and 1999 (at a helioradius of-73 AU). The quasiperiodic variations are in phase, with oxygen and helium having periods near 151 days, while protons exhibit a period of-146 days. The Voyager 1 ACRs vary by -30% with respect to the trend, and similar galactic cosmic ray variations, if they exist, must be less than -5%, probably much less. No similar, significant periodicities have been detected for these same ACR species at Voyager 2 (at 57 AU) during this period. We report on these and other periodicities in the Voyager Low Energy Charged Particle experiment measurements and address the possible connection between this -151-day ACR periodicity and the previously discovered-154-day periodicities in solar flares, the interplanetary magnetic field, and other phenomena.

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Section: Discussionmentioning

confidence: 99%

Periodicity of 151 days in outer heliospheric anomalous cosmic ray fluxes

Hill¹,

Hamilton²,

Krimigis³

2001

J. Geophys. Res.

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“…The measurements were made with the Low Energy Charged Particle Instrument (LECP; Krimigis et al 1977) on board the V1 spacecraft. The LECP instruments are solid-state detector (SSD) telescopes that measure the composition and intensities of ions at V1 and V2.…”

Section: Comparison With Observationsmentioning

confidence: 99%

Modelling anomalous cosmic ray oxygen in the heliosheath

Strauss

Potgieter

Ferreira

et al. 2010

A&A

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This paper discusses a numerical modulation model to describe anomalous cosmic ray acceleration and transport in the heliosheath, the portion of the heliosphere between the termination shock and the heliopause. The model is based on the well known Parker transport equation and includes, in addition to diffusive shock acceleration at the solar wind termination shock, momentum diffusion (Fermi II, stochastic acceleration) and adiabatic heating occurring in the heliosheath together with both a latitude dependent compression ratio and injection efficiency as inferred from hydrodynamic heliospheric models. The model is applied to the study of anomalous cosmic ray oxygen, with the resulting intensities compared to recent Voyager 1 spacecraft observations in the heliosheath.Comparison shows that the model is able to very satisfactorily reproduce these observations, which includes a modulated spectral form at the termination shock and subsequent unfolding into the heliosheath. It is concluded that a combination of momentum diffusion and adiabatic heating, under certain realistic assumption of the solar wind speed in the heliosheath, form a viable re-acceleration mechanism, or continuous acceleration process, to explain the very contentious anomalous cosmic ray observations in the heliosheath.

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“…The result of the correction is to reveal spectral features at energies below 2 MeV. We have included data from the Low Energy Charged Particle (LECP) instrument 7 to extend the spectra down to 0.04 MeV.…”

Section: Introductionmentioning

confidence: 99%

Termination shock particle spectral features

Cummings¹,

Stone²,

McDonald³

et al. 2006

AIP Conference Proceedings

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Abstract. Spectral features of energetic H ions accelerated at the termination shock may be evidence of two components. At low energies the energy spectrum is ~E . A second component appears above ~1 MeV with a spectrum of E -1.27 with a break at ~3.2 MeV. Even though the intensities upstream are highly variable, the same spectral break energies are observed, suggesting that these are durable features of the source spectrum. The acceleration processes for the two components may differ, with the lower energy component serving as the injection source for diffusive shock acceleration of the higher energy component. Alternatively, the spectral features may result from the energy dependence of the diffusion tensor that affects the threshold for diffusive shock acceleration.

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The Low Energy Charged Particle (LECP) experiment on the Voyager spacecraft

Cited by 202 publications

References 17 publications

Periodicity of 151 days in outer heliospheric anomalous cosmic ray fluxes

Periodicity of 151 days in outer heliospheric anomalous cosmic ray fluxes

Modelling anomalous cosmic ray oxygen in the heliosheath

Termination shock particle spectral features

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