Self-stabilizing criticality waves

An analysis is presented of a recently developed concept, so-called self-st abilizing criticality waves. These waves can be ignited in originally subcr itical systems under the condition that the burn up dependent properties of the system satisfy certain requirements, as is shown for an analytically s olvable model. The waves have a soliton character, i.e. as a consequence of the non-linear properties of the system they have a self-stabilizing form and a phase velocity that depends on the wave amplitude. For the analytical ly solvable model las far as the asymptotic waves are concerned) expression s are given for ignition conditions, wave form, amplitude (i.e. reactor pow er) and phase velocity. The results are corroborated by computer simulation s and the latter are also used for illustrating a non analytically solvable case and for studying the pre-ignition phase and the evolution to an asymp totic wave. (C) 2000 Elsevier Science Ltd. All rights reserved.