The fundamental behavior of the W7-X island divertor under detached conditions, which has been theoretically predicted with the EMC3-Eirene code, is re-examined here under the experimental conditions achieved so far and compared with the first experimental results. Both simulations and experiments cover a range of divertor configurations and plasma parameters, and show the following common trends: (1) with rising impurity radiation, the target heat load decreases ‘uniformly’ over the entire target surface in the sense that both the peak and average heat loads can drop by an order of magnitude. Impurity radiation (mainly from intrinsic carbon) occurs primarily at the plasma edge and the resulting negative impact on the stored energy is less than 10%. (2) When the total radiation exceeds a critical level, the target particle flux (the recycling flux Γrecy) begins to fall and can drop by a factor of 3–5 at high radiation levels without an obvious indication of significant volume recombination. (3) While Γrecy decreases, the divertor neutral pressure continues to build up and reaches a maximum, at which point Γrecy has declined significantly. (4) During detachment, the electron temperature at the last closed flux surface falls in a way that is not quantitatively understandable from parallel classical heat conduction processes. This paper presents a physical explanation of the numerical/experimental results described above. Furthermore, using the EMC3-Eirene code as a diagnostic tool, we are able, apparently for the first time, to provide a full quantitative analysis of each transport channel in the island divertor, aiming to clarify how the island divertor plasma self-regulates to maintain particle, energy, and momentum balance under detached conditions.

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In the past few decades, surface plasmon resonance (SPR) phenomenon along with optical fiber technology has emerged as a major area of research among the fiber optic sensing research groups. On the other hand, lossy mode resonance (LMR) is another kind of resonance phenomenon recently exploited for fiber optic sensing. LMR has several advantages over the well established SPR such as, free from specific polarization of light and capability of multiple LMR generation. Since LMR phenomenon is nascent for researchers and there are no review articles available till date, in this paper, we review the LMR phenomenon in applications involving sensing and wavelength filtering.

Transition metal dichalcogenides (TMDs) and their heterojunctions are drawing immense research interest for various applications including infrared detection. They are being studied with different semiconductor materials to explore their heterojunction properties. In this regard, we report a MoSe2/Si heterojunction broadband photodiode which is highly sensitive for a wide spectral range from 405 nm to 2500 nm wavelength with the maximum responsivity of ∼522 mA W−1 for 1100 nm of incident light. The hydrothermal synthesis approach leads to the imperfect growth of the MoSe2, creating defects in the lattice, which was confirmed by x-ray photo-spectroscopy. These sub-bandgap defects caused high optical absorption of the SWIR light as observed in the absorption spectra. The speed of the device ranges to 18/10 μs for 10 kHz modulated light. Furthermore, the photodetector has been fully operational even at zero bias voltage, making it a potential contender for self-powered photodetection.

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Continuous carbon fibers show dramatic promise as reinforcement materials to improve the stiffness, strength properties and design ability of 3D printed polymer parts. However current 3D printing methods have a very slow printing speed because the intrinsic slow and contact needed heat transfer disadvantages of the traditional resistive heating approach. We present a 3D microwave printing method by using the microwave for instantaneous and volumetric heating the continuous carbon fiber reinforced polymer (CCFRP) filament. This allows fabricating CCFRP components with much faster speed and higher printing amount compare with the traditional 3D printing technologies. To utilize the benefit of fast printing speed, the speed-variation 3D microwave printing is applied to adapt the diverse printing path and reduce the printing period. In this paper, a 3D microwave printing temperature control method by combining the prediction-model and step-proportional-integral-derivative control is researched to reduce the printing temperature difference of the CCFRP filaments during the speed-variation printing process. Three different CCFRP specimens with variation printing speed are compared, including a spanner, an aircraft and a spider from Nazca lines. The experimental results indicate that the new printing temperature control method for 3D microwave printing process dramatically reduces the temperature deviation. This technology solved a key problem of 3D microwave printing of continuous carbon fiber reinforced polymer composites and can be used to manufacture complex polymer-matrix composite materials.

Among the pool of Power-to-X technologies, plasmas show high potential for the efficient use of intermittent renewable energies. High efficiencies of CO 2 conversion have been reported while using microwave plasmas at vacuum conditions which are, however, not suitable for CO 2 mitigation at industrial scales.Here we show that ultrafast pulsation of microwaves allow significant improvements of energy efficiencies during CO 2 splitting at atmospheric pressure as compared to continuous wave operation of the microwave source. Moreover, by the interrogation of the plasma with time-resolved optical emission spectroscopy we can, for the first time, observe the evolution of the vibrational and rotational temperatures and define a time window where nonequilibrium can be expected at the beginning of the pulse of an atmospheric CO 2 microwave plasma. In spite of the evidence of nonequilibrium in our system, thermal mechanism appears to dominate the CO 2 dissociation. It is shown that a fine control of the energy deposition in the plasma is possible with ultrafast pulsation of the microwave energy supply.