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In this work, a 25 kW all silicon carbide (SiC) series-resonant converter (SRC) design is proposed to enable a single stage dc to dc conversion from 3kV to 540V (±270V) for future electric aircraft applications. The proposed SRC consists of a 3-level neutral-point-clamped (NPC) converter using 3.3kV discrete SiC MOSFETs on the primary side, a H-bridge converter using 900V SiC MOSFET modules on the secondary side and a high frequency (HF) transformer. The detailed design methods for the SRC power stage and the HF transformer are presented. Especially, a tradeoff between the complexity for the cooling system and the need for power density is addressed in the transformer design, leading to a novel multi-layer winding layout. To validate the effectiveness of the proposed SRC design, a converter prototype has been developed and comprehensive experimental studies are performed. 

The CLLC converter is widely used in the power electronic applications as a DC transformer, which can provide galvanic isolation, bidirectional power flow and an adjustable output voltage with the use of proper controls. As the most critical component in the CLLC converter, the high frequency (HF) transformer should be optimized according to the design targets, such as efficiency and power density. Starting with the analysis of the CLLC operating characteristics, this paper proposes a formal approach to design the HF transformer of a 100kW CLLC converter for a grid-tied application. The optimization method for the HF transformer is presented and the effect of the resonant inductor is analyzed. The optimized transformer is simulated with the finite element analysis (FEA) and Matlab/Simulink. 

Scintillators for radiation detection are of great significance in medical imaging, security, and nondestructive inspection. The current challenge for scintillators is to simultaneously achieve high scintillation light yield, fast radioluminescence, simple film fabrication, large X‐ray attenuation efficiency as well as stable and nontoxic compositions; no previous scintillators fulfill all the above requirements. Here, metal halide Rb₂AgBr₃, possessing defect‐bound excitonic radioluminescence, is shown as efficient and fast scintillators. This nontoxic and stable scintillator emits from excitons bound to neutral bromine vacancies, enjoying an efficient and spin‐allowed fast emission with minimized self‐absorption. Rb₂AgBr₃thus has a high light yield (25 600 photons MeV⁻¹), fast scintillation decay time (5.31 ns), and a record value of light yield versus decay time (4821 photons MeV⁻¹ns⁻¹). The close‐space sublimation method is developed for fast and scalable fabrication of oriented Rb₂AgBr₃films. The scintillator film is further integrated with commercial flat‐panel imagers, and the spatial resolution reaches 10.2 line pairs per millimeter at the modulation transfer function of 0.2, doubling the resolution of conventional CsI:Tl flat‐panel detectors. The dynamic X‐ray imaging and its use to real‐time monitoring of bone movement without ghosting effect is also demonstrated.