Dr. Tim Happel

Division Head of Plasma Dynamics

Tim Happel was born in Gießen in 1980 and studied physics at the Christian-Albrechts-Universität in Kiel from 2000 to 2006. During his diploma thesis, he gained his first insight into fusion research at the stellarator TJ-K. He worked on the characterization of micro-instabilities at the transition from closed to open field lines.

For his PhD, Tim Happel went to the Spanish fusion research laboratory at CIEMAT in Madrid, where the second largest stellarator in the world, TJ-II, is operated. There he developed a Doppler backscattering system, with which he was able to successfully observe plasma flows and their interaction with turbulent structures. For this work, Tim Happel received the Itoh Prize for Plasma Turbulence.

After completing his PhD, Tim Happel moved to the Max Planck Institute for Plasma Physics in Garching near Munich in 2011, where he continued his research into plasma flows at the ASDEX Upgrade tokamak. In this context, he has led the Turbulence research group since 2023. At IPP, he expanded his studies to include tokamak operation modes with enhanced energy confinement. He is particularly interested in the Improved Energy Confinement Mode (I-Mode) and plasmas with negative triangularity.

Selected publications

T. Happel, T. Pütterich, D. Told, M. Dunne, R. Fischer, et al.

Overview of initial negative triangularity plasma studies on the ASDEX Upgrade tokamak

Nuclear Fusion 63, 016002 (2023)

DOI

T. Happel, P. Manz, F. Ryter, M. Bernert, M. Dunne, et al.

The I-mode confinement regime at ASDEX Upgrade: global properties and characterization of strongly intermittent density fluctuations

Plasma Physics and Controlled Fusion 59, 014004 (2017)

DOI

T. Happel, T. Görler, P. Hennequin, C. Lechte, M. Bernert, et al.

Comparison of detailed experimental wavenumber spectra with gyrokinetic simulation aided by two-dimensional full-wave simulations

Plasma Physics and Controlled Fusion 59, 054009 (2017)

DOI

T. Happel, T. Estrada, E. Blanco, V. Tribaldos, A. Cappa, et al.

Doppler reflectometer system in the stellarator TJ-II

Review of Scientific Instruments 80, 073502 (2009)

DOI

T. Happel, F. Greiner, N. Mahdizadeh, B. Nold, M. Ramisch, et al.

Generation of Intermittent Turbulent Events at the Transition from Closed to Open Field Lines in a Toroidal Plasma

Physical Review Letters 102, 255001 (2009)

DOI