Speakers
Description
Advanced electron energy loss spectroscopy (EELS) requires energy precision on the meV scale to investigate low energy excitations in solid state samples. In conventional instruments, reaching this precision typically relies on passive filtering which leads to significant beam current loss. To address this, we report on the development of a compact 30 keV DC electron beamline that integrates an active monochromatization stage with a high resolution spectrometer. The design is based on the dual RF cavity manipulation concept previously proposed by our group, which has been validated through 3D self-consistent general particle tracer (GPT) simulations demonstrating an energy spread reduction by more than an order of magnitude without any current loss. In the current implementation, the system utilizes a 2.856 GHz RF cavity to perform a precision longitudinal phase space rotation, aiming to reduce the intrinsic energy spread of the beam toward the meV level. Complementing this source, the magnetic spectrometer architecture consists of a 90 degree dipole magnet and a three quadrupole lattice. This configuration employs a quadrupole doublet upstream for beam preparation and a single lens downstream to manage spectral magnification. The hardware integration of the beamline is substantially complete, and current efforts focus on multi-parameter optimization using GPT simulations. These studies incorporate 3D magnetic field maps to accurately model fringe field effects and reach the sub-eV resolution design goal.
| Working group | WG5 |
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