Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Discrete Particle Noise in Particle-in-Cell Simulations of Plasma Microturbulence

Journal Article · · Physics of Plasmas
DOI:https://doi.org/10.1063/1.2118729· OSTI ID:878221
Recent gyrokinetic simulations of electron temperature gradient (ETG) turbulence with flux-tube continuum codes vs. the global particle-in-cell (PIC) code GTC yielded different results despite similar plasma parameters. Differences between the simulations results were attributed to insufficient phase-space resolution and novel physics associated with toroidicity and/or global simulations. We have reproduced the results of the global PIC code using the flux-tube PIC code PG3EQ, thereby eliminating global effects as the cause of the discrepancy. We show that the late-time decay of ETG turbulence and the steady-state heat transport observed in these PIC simulations results from discrete particle noise. Discrete particle noise is a numerical artifact, so both these PG3EQ simulations and the previous GTC simulations have nothing to say about steady-state ETG turbulence and the associated anomalous heat transport. In the course of this work we develop three diagnostics which can help to determine if a particular PIC simulation has become dominated by discrete particle noise.
Research Organization:
Lawrence Livermore National Laboratory (LLNL), Livermore, CA
Sponsoring Organization:
USDOE
DOE Contract Number:
W-7405-ENG-48
OSTI ID:
878221
Report Number(s):
UCRL-JRNL-212536
Journal Information:
Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 12 Vol. 12; ISSN PHPAEN; ISSN 1070-664X
Country of Publication:
United States
Language:
English

References (24)

Collisional delta- f scheme with evolving background for transport time scale simulations journal December 1999
Kinetic theory for fluctuations and noise in computer simulation of plasma journal January 1979
Dielectric response and thermal fluctuations in gyrokinetic plasma journal April 1993
Thermostatted δf journal May 1999
Comparison of initial value and eigenvalue codes for kinetic toroidal plasma instabilities journal August 1995
A fully nonlinear characteristic method for gyrokinetic simulation journal January 1993
Plasma density behavior in the Hefei tokamak-7 journal July 2000
A unified Monte Carlo interpretation of particle simulations and applications to non‐neutral plasmas journal April 1994
Electron temperature gradient driven turbulence journal May 2000
Comparisons and physics basis of tokamak transport models and turbulence simulations journal March 2000
Scalings of Ion-Temperature-Gradient-Driven Anomalous Transport in Tokamaks journal July 1996
Role of nonlinear toroidal coupling in electron temperature gradient turbulence journal May 2005
The particle-continuum method: an algorithmic unification of particle-in-cell and continuum methods journal December 2004
Gyrokinetic approach in particle simulation journal January 1983
Partially Linearized Algorithms in Gyrokinetic Particle Simulation journal August 1993
Generalized weighting scheme for δ f particle‐simulation method journal April 1994
Shear-Alfvén waves in gyrokinetic plasmas journal October 2001
Gyrokinetic particle simulation of ion temperature gradient drift instabilities journal January 1988
A new bdelta f method for neoclassical transport studies journal August 1999
Adiabatic modifications to plasma turbulence theories journal January 1978
Fundamental statistical descriptions of plasma turbulence in magnetic fields journal April 2002
Prediction of Significant Tokamak Turbulence at Electron Gyroradius Scales journal November 2002
Electron Temperature Gradient Turbulence journal December 2000
Multigrid particle-in-cell simulations of plasma microturbulence journal August 2003

Similar Records

Gyrokinetic Simulations of ETG and ITG Turbulence
Conference · Tue Oct 03 00:00:00 EDT 2006 · OSTI ID:897932

Nonlinear low noise particle-in-cell simulations of electron temperature gradient driven turbulence
Journal Article · Sun Jan 14 23:00:00 EST 2007 · Physics of Plasmas · OSTI ID:20960075

Gyrokinetic particle simulation of microturbulence for general magnetic geometry and experimental profiles
Journal Article · Sat Feb 14 23:00:00 EST 2015 · Physics of Plasmas · OSTI ID:22408111