Runaway electron generation in a cooling plasma

Journal Article · Thu Dec 15 04:00:00 EST 2005 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.2148966· OSTI ID:20782390

Smith, H; Helander, P; Eriksson, L -G; Fueloep, T ^[1]

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1. Department of Radio and Space Science, Chalmers University of Technology, SE-412 96 Goeteborg (Sweden)

The usual calculation of Dreicer [Phys. Rev. 115, 238 (1959); 117, 329 (1960)] generation of runaway electrons assumes that the plasma is in a steady state. In a tokamak disruption this is not necessarily true since the plasma cools down quickly and the collision time for electrons at the runaway threshold energy can be comparable to the cooling time. The electron distribution function then acquires a high-energy tail which can easily be converted to a burst of runaways by the rising electric field. This process is investigated and simple criteria for its importance are derived. If no rapid losses of fast electrons occur, this can be a more important source of runaway electrons than ordinary Dreicer generation in tokamak disruptions.

• OSTI ID: 20782390
• 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

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
COOLING TIME
DISTRIBUTION FUNCTIONS
ELECTRIC FIELDS
ELECTRON COLLISIONS
ION COLLISIONS
PARTICLE LOSSES
PLASMA
PLASMA CONFINEMENT
PLASMA INSTABILITY
RUNAWAY ELECTRONS
STEADY-STATE CONDITIONS
THRESHOLD ENERGY
TOKAMAK DEVICES