Theoretical astrophysics and plasma physics at RPC

Research group

Research theme

Sub department

About

Related research groups

Disc distortion revisited

ArXiv 2411.04879 (2024)

Disc distortion revisited

Monthly Notices of the Royal Astronomical Society 91探花 University Press (OUP) (2024) stae2481

Evolution of the disky second generation of stars in globular clusters on cosmological timescale

(2024)

Authors:

Peter Berczik, Taras Panamarev, Maryna Ishchenko, Bence Kocsis

Extracting Astrophysical Information of Highly-Eccentric Binaries in the Millihertz Gravitational Wave Band

(2024)

Authors:

Zeyuan Xuan, Smadar Naoz, Alvin KY Li, Bence Kocsis, Erik Petigura, Alan M Knee, Jess McIver, Kyle Kremer, Will M Farr

Optimisation of gyrokinetic microstability using adjoint methods

Journal of Plasma Physics Cambridge University Press 90:4 (2024) 905900406

Authors:

Georgia Acton, Michael Barnes, S Newton, H Thienpondt

Abstract:

Microinstabilities drive turbulent fluctuations in inhomogeneous, magnetised plasmas. In the context of magnetic confinement fusion devices, this leads to an enhanced transport of particles, momentum and energy, thereby degrading confinement. In this work, we describe an application of the adjoint method to efficiently determine variations of gyrokinetic linear growth rates on a general set of external parameters in the local 未f-gyrokinetic model. We then offer numerical verification of this approach. When coupled with gradient-based techniques, this methodology can facilitate the optimisation process for the microstability of the confined plasmas across a high-dimensional parameter space. We present a numerical demonstration wherein the ion-temperature-gradient instability growth rate in a tokamak plasma is minimised with respect to flux surface shaping parameters. The adjoint method approach demonstrates a significant computational speed-up compared with a finite-difference gradient calculation.