A5021609699- Gyrotron and Vacuum Electronics Research
- Advanced NMR Techniques and Applications
- Particle accelerators and beam dynamics
- Electron Spin Resonance Studies
- Atomic and Subatomic Physics Research
- Superconducting Materials and Applications
- Spectroscopy and Quantum Chemical Studies
- Solid-state spectroscopy and crystallography
- Muon and positron interactions and applications
- Photochemistry and Electron Transfer Studies
- Particle Accelerators and Free-Electron Lasers
- NMR spectroscopy and applications
- Quantum, superfluid, helium dynamics
- Perovskite Materials and Applications
- Scientific Research and Discoveries
- Pulsed Power Technology Applications
ETH Zurich
2020-2024
Charles Humbert 8
2021
Lead-halide perovskites increasingly mesmerize researchers because they exhibit a high degree of structural defects and dynamics yet nonetheless offer an outstanding (opto)electronic performance on par with the best examples structurally stable defect-free semiconductors. This highly unusual feature necessitates adoption experimental theoretical mindset reexamination techniques that may be uniquely suited to understand these materials. Surprisingly, suite methods for characterization...
Dynamical decoupling sequences detect spin system and solvent-induced decoherence contributions for nitroxides, trityl radicals gadolinium complexes in glassy water–glycerol.
A significant effort has recently been initiated at ETHZ for the development of high frequency, power, frequency-agile gyrotrons DNP-NMR spectroscopy. In this context an in house cavity interaction code is under development. paper, some details on new and preliminary results will be presented.
Magic angle spinning (MAS) dynamic nuclear polarization (DNP) increases the signal intensity of solid-state magnetic resonance. DNP typically uses continuous wave (CW) microwave irradiation close to resonance frequency unpaired electron spins. In this study, we demonstrate that frequency-chirped microwaves improve performance under MAS. By modulating gyrotron anode potential, generate a train chirps with maximum bandwidth 310 MHz and incident power on sample 18 W. We characterize efficiency...
Cryogenic magic angle spinning (MAS) is a standard technique utilized for dynamic nuclear polarization (DNP) in solid-state magnetic resonance (NMR). Here we describe the optimization and implementation of stator cryogenic MAS with 9.5 mm diameter spherical rotors, allowing DNP experiments on large sample volumes. Designs rotor build recent advancements spheres take step further to incorporate insert eject temperature-independent stability ±1 Hz. At field 7 T at 2.0 kHz temperature 105-107...
Abstract The measurement and manipulation of the microwave polarization emitted from a frequency-agile 198 GHz gyrotron for dynamic nuclear (DNP) are demonstrated. In general, gyrotrons emit linearly polarized radiation, yet in this case elliptical is observed window. Indeed, half power circularly while other with 60 ∘ respect to horizontal plane. For optimal use DNP experiments, converted into circular Martin-Puplett interferometer (MPI). dependence enhancement on was investigated by...
A model is presented for simulating the electron beam within entire gyrotron geometry using an optics code. The incorporates influence of electromagnetic fields generated by cavity's operational mode through a simple self-consistent approach. This simulation method proves highly beneficial investigating effects occurring complete structure. One such application includes examination ions and electrons, resulting from ionization residual gas molecules upon collision with beam. By calculating...
The proper placement of gyrotron relative to the magnetic field is necessary for optimal performance. A gyrotron-alignment platform capable independent, precise adjustment in five degrees freedom has been developed. effectiveness this experimentally demonstrated by alignment a 198 GHz used Dynamic Nuclear Polarization.
Abstract. Cryogenic magic-angle spinning (MAS) is a standard technique utilized for Dynamic Nuclear Polarization (DNP) in solid state nuclear magnetic resonance (NMR). Here we describe the optimization and implementation of stator cryogenic MAS with spherical rotors, allowing DNP experiments on large sample volumes. Designs rotor build recent advancements spheres, take step further to incorporate sample-insert/eject temperature-independent stability +/- 1 Hz. At field 7 T at 2.0 kHz...
Versatile instrumentation including a frequency-agile gyrotron as the microwave source, Martin-Puplett interferometer to modify polarization, Nuclear Magnetic Resonance (NMR) spectrometer with cryogenic magic angle spinning, well an electron spin detection circuit is presented. The combination of these state-of-the-art technologies allows recording high-performance dynamic nuclear polarization spectra, method used enhance sensitivity NMR experiments via irradiation.
Abstract The measurement and manipulation of the microwave polarization emitted from a frequency-agile 198 GHz gyrotron for dynamic nuclear (DNP) is demonstrated. In general, gyrotrons emit linearly polarized radiation, yet in this case elliptical observed window. Indeed, half power circularly while other with 60° respect to horizontal plane. For optimal use DNP experiments, converted into circular Martin-Puplett interferometer (MPI). dependence enhancement on was investigated by modifying...
The manuscript presents a dynamical decoupling study of three EPR spin labels in glassy water-glycerol, corresponding to common experimental conditions for dipolar spectroscopy. main text and the supporting information (split into part A B) are uploaded as separate PDF documents contain all interpreting reproducing findings.
The manuscript presents a dynamical decoupling study of three EPR spin labels in glassy water-glycerol, corresponding to common experimental conditions for dipolar spectroscopy. main text and the supporting information (split into part A B) are uploaded as separate PDF documents contain all interpreting reproducing findings.<br>