TEXTOR

TEXTOR
Bodoklecksel · CC BY-SA 3.0 · source
Name	TEXTOR
Type	Tokamak
Location	Jülich, North Rhine-Westphalia, Germany
Operator	Forschungszentrum Jülich
Construction started	1970s
Operational	1982–2013
Decommissioned	2013

TEXTOR

TEXTOR was a medium-sized tokamak operated by Forschungszentrum Jülich in Jülich, North Rhine-Westphalia, Germany. It served as a national and international facility for plasma physics, fusion engineering, and materials research, attracting collaborations from institutions such as the Max Planck Institute for Plasma Physics, Culham Centre for Fusion Energy, Princeton Plasma Physics Laboratory, and the ITER Organization. The device contributed experimental data relevant to projects like ITER, JET, and conceptual studies for future reactors including DEMO and advanced stellarator concepts such as Wendelstein 7-X.

Introduction

TEXTOR was designed as a limiter tokamak with a focus on wall interaction, plasma-material interaction, and disruption physics. It complemented other European devices including ASDEX Upgrade, JET, TORE SUPRA, and MAST) by providing unique capabilities for high-power neutral beam injection experiments and material testing under plasma fluxes. The facility hosted visiting researchers from CERN, Oak Ridge National Laboratory, Lawrence Livermore National Laboratory, and numerous universities such as Technische Universität München, University of Oxford, École Polytechnique, and Imperial College London.

Design and Technical Specifications

The TEXTOR machine featured a toroidal vacuum vessel surrounded by copper and steel magnet structures, with major and minor radii optimized for mid-size studies. Key subsystems included toroidal field coils, poloidal field coils, a central solenoid, radio-frequency heating, and neutral beam injectors sourced through collaborations with European Space Agency-linked suppliers and national labs. Diagnostics aboard TEXTOR encompassed Thomson scattering, charge-exchange recombination spectroscopy, bolometry, Langmuir probes, and mirror diagnostics developed in partnership with Max Planck Society, CEA, and Oak Ridge National Laboratory groups. The device was equipped to handle plasma currents, densities, and temperatures comparable to devices like DIII-D and T-10, enabling studies of confinement, edge localized modes, and impurity transport. Reactor-relevant features included dedicated test limiters for tungsten and carbon-fiber-composite tiles, instrumentation for neutron flux assessment, and sample exposure systems used by institutions such as KIT and CEA.

Operational History

TEXTOR began operations in the early 1980s and evolved through upgrades coordinated with European fusion programs such as the European Fusion Development Agreement and national funding bodies including the German Federal Ministry of Education and Research. Over its decades-long campaign, TEXTOR hosted campaigns addressing sawtooth control, disruption mitigation, impurity seeding, and divertor physics, often in concert with simulation efforts at groups like IPP Garching and CCFE. International experimental campaigns included joint programs with JET on plasma-wall interaction comparisons, collaborative studies with ASDEX Upgrade on tungsten behavior, and cross-validation of diagnostics developed at Princeton University and MIT. The machine supported doctoral and postdoctoral research from universities such as RWTH Aachen University, Heidelberg University, and Ecole Normale Supérieure.

Research and Contributions

TEXTOR produced significant results in plasma-surface interaction, erosion and redeposition processes, and impurity transport modeling that informed material choices for large-scale projects such as ITER and design studies for DEMO. Notable research outputs included measurements of sputtering yields for tungsten and graphite under hydrogenic plasmas, characterization of mixed-material layers relevant to JET tritium retention studies, and experimental validation of codes developed at CCFE, IPP, and Princeton Plasma Physics Laboratory. The facility contributed to the development and testing of disruption mitigation techniques using massive gas injection and shattered pellet injection concepts later implemented or contemplated at JT-60SA and ITER. TEXTOR's diagnostic innovations intertwined with developments at Culham Laboratory, Max Planck Institute for Plasma Physics, and CEA enabling cross-facility calibration campaigns and benchmark datasets used by computational efforts at ITER Organization and national laboratories.

Decommissioning and Legacy

After decades of service, operations wound down and TEXTOR was decommissioned in 2013 as research priorities shifted toward devices like Wendelstein 7-X, ITER, and next-step tokamaks. Parts of the TEXTOR program and expertise migrated to other facilities at Forschungszentrum Jülich and collaborating centers including KIT and IPP Garching. Legacy impacts include extensive datasets on plasma-material interaction, tested components and diagnostic designs adopted by JET and ASDEX Upgrade, and a cohort of experimentalists now working at institutions such as ITER Organization, Culham Centre for Fusion Energy, Princeton Plasma Physics Laboratory, and various European universities. The machine is frequently cited in literature on material selection for fusion reactors, disruption physics, and edge plasma phenomena, and its experimental records continue to inform modeling efforts at national and international centers.

Category:Tokamaks Category:Fusion reactors in Germany Category:Forschungszentrum Jülich