Large-scale turbulence, shocks, and charged-particle acceleration

Research output: Chapter in Book/Report/Conference proceedingChapter

Abstract

We discuss the physics of particle acceleration by shocks moving in turbulent astrophysical plasmas. We suggest that the observed lack of agreement of energetic particles and shock properties in the heliosphere is likely to be a result of fluctuations and turbulence in the upstream fluid. Shock acceleration takes time, so the observations of particles at any given point and time at a shock reflects some combination of the history prior to the time of observation. Further, since the particles are mobile, there is spatial averaging as well. It follows that the shock properties observed by a spacecraft should not correlate well with the accelerated particles. Additionally, the upstream turbulence, and in particular, the fluctuations in plasma density have a large effect on the downstream magnetic field. These effects may also help to understand the magnetic field observed by Voyager 1 in the heliosheath.

Original languageEnglish (US)
Title of host publicationAIP Conference Proceedings
Pages243-257
Number of pages15
Volume932
DOIs
StatePublished - 2007
EventTURBULENCE AND NONLINEAR PROCESSES IN ASTROPHYSICAL PLASMAS: 6th Annual International Astrophysics Conference - Oahu, HI, United States
Duration: Mar 16 2007Mar 22 2007

Other

OtherTURBULENCE AND NONLINEAR PROCESSES IN ASTROPHYSICAL PLASMAS: 6th Annual International Astrophysics Conference
CountryUnited States
CityOahu, HI
Period3/16/073/22/07

Fingerprint

particle acceleration
charged particles
turbulence
shock
upstream
heliosphere
energetic particles
magnetic fields
plasma density
astrophysics
spacecraft
histories
physics
fluids

Keywords

  • Cosmic rays
  • Particle acceleration
  • Turbulence

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Large-scale turbulence, shocks, and charged-particle acceleration. / Giacalone, Joe; Jokipii, J. Randy.

AIP Conference Proceedings. Vol. 932 2007. p. 243-257.

Research output: Chapter in Book/Report/Conference proceedingChapter

Giacalone, J & Jokipii, JR 2007, Large-scale turbulence, shocks, and charged-particle acceleration. in AIP Conference Proceedings. vol. 932, pp. 243-257, TURBULENCE AND NONLINEAR PROCESSES IN ASTROPHYSICAL PLASMAS: 6th Annual International Astrophysics Conference, Oahu, HI, United States, 3/16/07. https://doi.org/10.1063/1.2778971
@inbook{33500507b34e498d8ba6d8030e1c3a0c,
title = "Large-scale turbulence, shocks, and charged-particle acceleration",
abstract = "We discuss the physics of particle acceleration by shocks moving in turbulent astrophysical plasmas. We suggest that the observed lack of agreement of energetic particles and shock properties in the heliosphere is likely to be a result of fluctuations and turbulence in the upstream fluid. Shock acceleration takes time, so the observations of particles at any given point and time at a shock reflects some combination of the history prior to the time of observation. Further, since the particles are mobile, there is spatial averaging as well. It follows that the shock properties observed by a spacecraft should not correlate well with the accelerated particles. Additionally, the upstream turbulence, and in particular, the fluctuations in plasma density have a large effect on the downstream magnetic field. These effects may also help to understand the magnetic field observed by Voyager 1 in the heliosheath.",
keywords = "Cosmic rays, Particle acceleration, Turbulence",
author = "Joe Giacalone and Jokipii, {J. Randy}",
year = "2007",
doi = "10.1063/1.2778971",
language = "English (US)",
isbn = "0735404437",
volume = "932",
pages = "243--257",
booktitle = "AIP Conference Proceedings",

}

TY - CHAP

T1 - Large-scale turbulence, shocks, and charged-particle acceleration

AU - Giacalone, Joe

AU - Jokipii, J. Randy

PY - 2007

Y1 - 2007

N2 - We discuss the physics of particle acceleration by shocks moving in turbulent astrophysical plasmas. We suggest that the observed lack of agreement of energetic particles and shock properties in the heliosphere is likely to be a result of fluctuations and turbulence in the upstream fluid. Shock acceleration takes time, so the observations of particles at any given point and time at a shock reflects some combination of the history prior to the time of observation. Further, since the particles are mobile, there is spatial averaging as well. It follows that the shock properties observed by a spacecraft should not correlate well with the accelerated particles. Additionally, the upstream turbulence, and in particular, the fluctuations in plasma density have a large effect on the downstream magnetic field. These effects may also help to understand the magnetic field observed by Voyager 1 in the heliosheath.

AB - We discuss the physics of particle acceleration by shocks moving in turbulent astrophysical plasmas. We suggest that the observed lack of agreement of energetic particles and shock properties in the heliosphere is likely to be a result of fluctuations and turbulence in the upstream fluid. Shock acceleration takes time, so the observations of particles at any given point and time at a shock reflects some combination of the history prior to the time of observation. Further, since the particles are mobile, there is spatial averaging as well. It follows that the shock properties observed by a spacecraft should not correlate well with the accelerated particles. Additionally, the upstream turbulence, and in particular, the fluctuations in plasma density have a large effect on the downstream magnetic field. These effects may also help to understand the magnetic field observed by Voyager 1 in the heliosheath.

KW - Cosmic rays

KW - Particle acceleration

KW - Turbulence

UR - http://www.scopus.com/inward/record.url?scp=36349002465&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=36349002465&partnerID=8YFLogxK

U2 - 10.1063/1.2778971

DO - 10.1063/1.2778971

M3 - Chapter

AN - SCOPUS:36349002465

SN - 0735404437

SN - 9780735404434

VL - 932

SP - 243

EP - 257

BT - AIP Conference Proceedings

ER -