SPACE PLASMA SIMULATION
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SPACE PLASMA SIMULATION |
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Numerical SimulationA plasma is made up of charged particles (usually mostly electrons and protons) which feel forces due to magnetic and electric fields. In a space plasma the electromagnetic fields are controlled to a large extent by the currents carried by the particles themselves.Plasmas are notoriously difficult to control and understand because of the feedback between the electromagnetic field and the motions of the particles. Observations of space plasmas show that nonlinear phenomena (shocks, particle acceleration, magnetic reconnection, etc.) abound. In order to study space plasmas we use numerical models or simulations, where the motion of computational "particles" is followed in the self-consistently evolving electromagnetic fields. These simulations involving solving Maxwell's equations in some domain, and simultaneously keeping track of between 10 and 100 million simulation particles! To carry out such large simulations we have an ongoing development programme for parallel plasma simulation algorithms. Many of our current simulations are done on a set of workstations running a simulation code which uses PVM. At the moment, we are building a PC cluster (the CHEEP project) to achieve even larger and faster simulations and to keep the price down! Large scale simulations of plasmas allow us to study nonlinear effects as waves and particles interact, and also the structure of the collisionless bow shock which stands in the solar wind upstream of the Earth's magnetosphere. See Science Topics for some examples. |
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Created February, 1999 by David Burgess |