skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Simulations of dusty plasmas using a special-purpose computer system designed for gravitational N-body problems

Abstract

Simulations of dusty plasmas were performed using GRAPE-6, a special-purpose computer designed for gravitational N-body problems. The collective behavior of dust particles, which are injected into the plasma, was studied by means of three-dimensional computer simulations. As an example of a dusty plasma simulation, experiments on Coulomb crystals in plasmas are simulated. Formation of a quasi-two-dimensional Coulomb crystal has been observed under typical laboratory conditions. Another example was to simulate movement of dust particles in plasmas under microgravity conditions. Fully three-dimensional spherical structures of dust clouds have been observed. For the simulation of a dusty plasma in microgravity with 3x10{sup 4} particles, GRAPE-6 can perform the whole operation 1000 times faster than by using a Pentium 4 1.6 GHz processor.

Authors:
; ; ; ; ; ;  [1];  [2]
  1. Faculty of Engineering, Shizuoka University, 3-5-1 Johoku, Hamamatsu 432-8561 (Japan)
  2. (Japan)
Publication Date:
OSTI Identifier:
20782426
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 13; Journal Issue: 1; Other Information: DOI: 10.1063/1.2163815; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; COMPUTERIZED SIMULATION; CRYSTALS; DUSTS; GHZ RANGE; MANY-BODY PROBLEM; PLASMA; PLASMA SIMULATION; SPHERICAL CONFIGURATION; THREE-DIMENSIONAL CALCULATIONS

Citation Formats

Yamamoto, K., Mizuno, Y., Hibino, S., Inuzuka, H., Cao, Y., Liu, Y., Yazawa, K., and Hamamatsu Metrix Co., Ltd., 1-4-10-8 Shinmiyakoda, Hamamatsu 431-2103. Simulations of dusty plasmas using a special-purpose computer system designed for gravitational N-body problems. United States: N. p., 2006. Web. doi:10.1063/1.2163815.
Yamamoto, K., Mizuno, Y., Hibino, S., Inuzuka, H., Cao, Y., Liu, Y., Yazawa, K., & Hamamatsu Metrix Co., Ltd., 1-4-10-8 Shinmiyakoda, Hamamatsu 431-2103. Simulations of dusty plasmas using a special-purpose computer system designed for gravitational N-body problems. United States. doi:10.1063/1.2163815.
Yamamoto, K., Mizuno, Y., Hibino, S., Inuzuka, H., Cao, Y., Liu, Y., Yazawa, K., and Hamamatsu Metrix Co., Ltd., 1-4-10-8 Shinmiyakoda, Hamamatsu 431-2103. Sun . "Simulations of dusty plasmas using a special-purpose computer system designed for gravitational N-body problems". United States. doi:10.1063/1.2163815.
@article{osti_20782426,
title = {Simulations of dusty plasmas using a special-purpose computer system designed for gravitational N-body problems},
author = {Yamamoto, K. and Mizuno, Y. and Hibino, S. and Inuzuka, H. and Cao, Y. and Liu, Y. and Yazawa, K. and Hamamatsu Metrix Co., Ltd., 1-4-10-8 Shinmiyakoda, Hamamatsu 431-2103},
abstractNote = {Simulations of dusty plasmas were performed using GRAPE-6, a special-purpose computer designed for gravitational N-body problems. The collective behavior of dust particles, which are injected into the plasma, was studied by means of three-dimensional computer simulations. As an example of a dusty plasma simulation, experiments on Coulomb crystals in plasmas are simulated. Formation of a quasi-two-dimensional Coulomb crystal has been observed under typical laboratory conditions. Another example was to simulate movement of dust particles in plasmas under microgravity conditions. Fully three-dimensional spherical structures of dust clouds have been observed. For the simulation of a dusty plasma in microgravity with 3x10{sup 4} particles, GRAPE-6 can perform the whole operation 1000 times faster than by using a Pentium 4 1.6 GHz processor.},
doi = {10.1063/1.2163815},
journal = {Physics of Plasmas},
number = 1,
volume = 13,
place = {United States},
year = {Sun Jan 15 00:00:00 EST 2006},
month = {Sun Jan 15 00:00:00 EST 2006}
}
  • We describe GRAPE-4, a special-purpose computer for gravitational N-body simulations. In gravitational N-body simulations, almost all computing time is spent for the calculation of interaction between particles. GRAPE-4 is a specialized hardware to calculate the interaction between particles. It is used with a general-purpose host computer that performs all calculations other than the force calculation. With this architecture, it is relatively easy to realize a massively parallel system. In 1991, we developed the GRAPE-3 system with the peak speed equivalent to 14.4 Gflops. It consists of 48 custom pipelined processors. In 1992 we started the development of GRAPE-4. The GRAPE-4more » system will consist of 1920 custom pipeline chips. Each chip has the speed of 600 Mflops, when operated on 30 MHz clock. A prototype system with two custom LSIs has been completed July 1994, and the full system is now under manufacturing.« less
  • Increasingly, ground water hydrologists and engineers must solve saturated/unsaturated flow and transport problems. The unsaturated component of flow is especially important when considering transport of contaminants that originate from surface or near-surface sources such as waste spill sites, landfills, and hazardous waste storage sites. Numerical solution of such problems has been accomplished with special purpose computer programs developed for solution of unsaturated flow problems. However, general purpose partial differential equation (PDE) solvers also exist, which often provide greater model flexibility. In this paper, the performance of PDE2D, a general PDE solver, and SWMS-2D, a special purpose program, are compared formore » solution of unsaturated flow and transport problems. Both programs accurately calculated changes in water volume in the flow domain for four examples, but PDE2D did not calculate boundary fluxes as well as SWMS-2D, resulting in high mass balance errors. However, PDE2D yielded a smoother solution of the example solute transport problem, despite a large mass balance error. SWMS-2D offers ease of use and excellent mass balances while PDE2D offers the user greater flexibility in terms of the types of problems solved, and a grid generator that ensures that the element size and distribution of elements are appropriate for a given problem.« less
  • The authors present the architecture of a special-purpose computer for logic simulation using distributed processing. The architecture is based on the utilization of inexpensive microprocessors interconnected by a communication structure. The communication structure is cross-point based for simple evaluations and time-shared parallel bus based for functional evaluations. Analysis is carried out to show that the performance of the proposed simulator is better by over two orders of magnitude than traditional logic simulation carried out on a general-purpose computer. Also, the power of a simulator is proportional to the number of slave processors over a certain range. 12 references.
  • N-body simulations show that homogeneous gravitational clustering in an expanding universe evolves slowly through a series of quasi-equilibrium states. This fundamental result, in agreement with previous theory, greatly simplifies the description of clustering, especially in the nonlinear regime. Detailed comparisons of the thermodynamic theory with these new N-body experiments show that, for a given initial distribution, the rate and degree of relaxation toward the thermodynamic distribution are greater for larger values of Omega(0). This rate is modified if there is a large initial peculiar velocity dispersion, or a very small softening parameter, but the asymptotic state does not depend significantlymore » on either of these. Initially cold or warm Omega(0) = 1 models with a Poisson distribution relax very quickly to the thermodynamic form. They come into agreement with the theory after the universe expands by a factor of about 1.5. The three-dimensional volume and the two-dimensional projected distribution functions also agree well with each other. 12 references.« less