A5050778493- Magnetic confinement fusion research
- Particle accelerators and beam dynamics
- Diamond and Carbon-based Materials Research
- Gyrotron and Vacuum Electronics Research
- High-pressure geophysics and materials
- Force Microscopy Techniques and Applications
- Atomic and Subatomic Physics Research
- NMR spectroscopy and applications
- Ion-surface interactions and analysis
- Ionosphere and magnetosphere dynamics
- Electronic and Structural Properties of Oxides
- Magneto-Optical Properties and Applications
- Electron Spin Resonance Studies
- Characterization and Applications of Magnetic Nanoparticles
- Advanced NMR Techniques and Applications
- Superconducting Materials and Applications
- Fusion materials and technologies
- Advanced Numerical Analysis Techniques
University of Stuttgart
2013-2017
University of Oxford
2015
Max Planck Institute for Plasma Physics
2010-2012
Max Planck Society
2010-2012
To study the magnetic dynamics of superparamagnetic nanoparticles we use scanning probe relaxometry and dephasing nitrogen-vacancy (NV) center in diamond, characterizing spin-noise a single 10-nm magnetite particle. Additionally, show anisotropy NV sensitivity's dependence on applied decoherence measurement method. By comparing change relaxation (T 1 ) 2 time when nanoparticle over it, are able to extract nanoparticle's diameter distance from using an Ornstein-Uhlenbeck model for...
We present a novel spectroscopy protocol based on optimal control of single quantum system. It enables measurements with quantum-limited sensitivity (\eta_\omega ~ 1/sqrt(T_2^*),T_2^* denoting the system's coherence time) but has an orders magnitude larger dynamic range than pulsed methods previously employed for this task. employ to image nanoscale magnetic fields scanning NV center in diamond. Here, our scheme quantitative imaging strongly inhomogeneous field scan without closed-loop...
ASDEX Upgrade has been operated with tungsten-coated plasma-facing components for several years. H-mode operation good confinement demonstrated. Nevertheless, purely neutral beam injection-heated H-modes reduced gas puff, moderate heating power or/and increased triangularity tend to accumulate tungsten, followed by a radiative collapse. Under these conditions, central electron cyclotron resonance (ECRH), usually in X2 polarization, changes the impurity transport plasma centre, reducing...
Magnetic sensing and imaging instruments are important tools in biological material sciences. There is an increasing demand for attaining higher sensitivity spatial resolution, with implementations using a single qubit offering potential improvements both directions. In this article we describe scanning magnetometer based on the nitrogen-vacancy center diamond as sensor. By means of quantum-assisted readout scheme together advances photon collection efficiency, our device exhibits...
The new electron cyclotron resonance heating (ECRH) system at the ASDEX Upgrade tokamak allows for an adjustment of polarization injected ECRH beam during plasma discharges. Three sniffer probes millimeter wave stray radiation, with broad and insensitive radiation characteristics, have been installed around torus to monitor nonabsorbed radiation. influence varying ECRH-beam on detected is studied. For perpendicular X2 minimum detectable amount wrong (O2-mode) found be 5%. also full change...
Due to imperfection of the single path absorption, ECRH at ASDEX Upgrade (AUG) is always accompanied by stray radiation in vacuum vessel. New scenarios with O2 and X3 heating schemes extend operational space, but they have also potential increase level radiation. There are hazards for invessel components. Damage on electric cables has already been encountered. It therefore necessary monitor control respect level. At AUG a system Sniffer antennas equipped microwave detection diodes installed....