Sandpile modelling of pellet pacing in fusion plasmas

• Main Authors: Bowie, C. A, Hole, M. J
• Format: Journal Article
• Language: English
• Published: 21-12-2019
• Subjects: Physics - Plasma Physics
• DOI: 10.48550/arxiv.1912.10196

Phys. Rev. E 101, 013207 (2020) Sandpile models have been used to provide simple phenomenological models
without incorporating the detailed features of a fully featured model. The
Chapman sandpile model Chapman et al Physical Review Letters 86, 2814 (2001)
has been used as an analogue for the behaviour of a plasma edge, with mass loss
events being used as analogues for ELMs. In this work we modify the Chapman
sandpile model by providing for both increased and intermittent driving. We
show that the behaviour of the sandpile, when continuously fuelled at very high
driving, can be determined analytically by a simple algorithm. We observe that
the size of the largest avalanches is better reduced by increasing constant
driving than by the intermittent introduction of `pellets' of sand. Using the
sandpile model as a reduced model of ELMing behaviour, we conject that ELM
control in a fusion plasma may similarly prove more effective with increased
total fuelling than with pellet addition.