@article{TurdumamatovBeldaHeuermann2024,
  author    = {Turdumamatov, Samat and Belda, Aljoscha and Heuermann, Holger},
  title     = {Shaping a decoupled atmospheric pressure microwave plasma with antenna structures, Maxwell's equations, and boundary conditions},
  series = {IEEE Transactions on Plasma Science},
  journal   = {IEEE Transactions on Plasma Science},
  number    = {Early Access},
  publisher = {IEEE},
  issn      = {0093-3813 (Print)},
  doi       = {10.1109/TPS.2024.3383589},
  pages     = {1 -- 9},
  year      = {2024},
  abstract  = {This article addresses the need for an innovative technique in plasma shaping, utilizing antenna structures, Maxwell's laws, and boundary conditions within a shielded environment. The motivation lies in exploring a novel approach to efficiently generate high-energy density plasma with potential applications across various fields. Implemented in an E01 circular cavity resonator, the proposed method involves the use of an impedance and field matching device with a coaxial connector and a specially optimized monopole antenna. This setup feeds a low-loss cavity resonator, resulting in a high-energy density air plasma with a surface temperature exceeding 3500 o C, achieved with a minimal power input of 80 W. The argon plasma, resembling the shape of a simple monopole antenna with modeled complex dielectric values, offers a more energy-efficient alternative compared to traditional, power-intensive plasma shaping methods. Simulations using a commercial electromagnetic (EM) solver validate the design's effectiveness, while experimental validation underscores the method's feasibility and practical implementation. Analyzing various parameters in an argon atmosphere, including hot S -parameters and plasma beam images, the results demonstrate the successful application of this technique, suggesting its potential in coating, furnace technology, fusion, and spectroscopy applications.},
  language  = {en}
}
@article{SchoppRohrbachLangeretal.2024,
  author    = {Schopp, Christoph and Rohrbach, Felix and Langer, Luc and Heuermann, Holger},
  title     = {Detection of welding wire length by active S11 measurement},
  series = {IEEE Transactions on Plasma Science},
  journal   = {IEEE Transactions on Plasma Science},
  number    = {Early Access},
  publisher = {IEEE},
  issn      = {0093-3813 (Print)},
  doi       = {10.1109/TPS.2024.3356659},
  pages     = {1 -- 6},
  year      = {2024},
  abstract  = {A novel method to determine the extruded length of a metallic wire for a directed energy deposition (DED) process using a microwave (MW) plasma jet with a straight-through wire feed is presented. The method is based on the relative comparison of the measured frequency response obtained by the large-signal scattering parameter (Hot-S) technique. In the practical working range, repeatability of less than 6\% for a nonactive plasma and 9\% for the active plasma state is found. Measurements are conducted with a focus on a simple solution to decrease the processing time and reduce the integration time of the process into the existing hardware. It is shown that monitoring a single frequency for magnitude and phase changes is sufficient to achieve good accuracy. A combination of different measurement values to determine the length is possible. The applicability to different diameter of the same material is shown as well as a contact detection of the wire and metallic substrate.},
  language  = {en}
}
@article{WindmuellerSchapsZantisetal.2024,
  author    = {Windm{\"u}ller, Anna and Schaps, Kristian and Zantis, Frederik and Domgans, Anna and Taklu, Bereket Woldegbreal and Yang, Tingting and Tsai, Chih-Long and Schierholz, Roland and Yu, Shicheng and Kungl, Hans and Tempel, Hermann and Dunin-Borkowski, Rafal E. and H{\"u}ning, Felix and Hwang, Bing Joe and Eichel, R{\"u}diger-A.},
  title     = {Electrochemical activation of LiGaO2: implications for ga-doped garnet solid electrolytes in li-metal batteries},
  series = {ACS Applied Materials \& Interfaces},
  volume    = {16},
  journal   = {ACS Applied Materials \& Interfaces},
  number    = {30},
  publisher = {ACS Publications},
  address   = {Washington, DC},
  issn      = {39181-3919},
  doi       = {10.1021/acsami.4c03729},
  pages     = {14 Seiten},
  year      = {2024},
  abstract  = {Ga-doped Li7La3Zr2O12 garnet solid electrolytes exhibit the highest Li-ion conductivities among the oxide-type garnet-structured solid electrolytes, but instabilities toward Li metal hamper their practical application. The instabilities have been assigned to direct chemical reactions between LiGaO2 coexisting phases and Li metal by several groups previously. Yet, the understanding of the role of LiGaO2 in the electrochemical cell and its electrochemical properties is still lacking. Here, we are investigating the electrochemical properties of LiGaO2 through electrochemical tests in galvanostatic cells versus Li metal and complementary ex situ studies via confocal Raman microscopy, quantitative phase analysis based on powder X-ray diffraction, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and electron energy loss spectroscopy. The results demonstrate considerable and surprising electrochemical activity, with high reversibility. A three-stage reaction mechanism is derived, including reversible electrochemical reactions that lead to the formation of highly electronically conducting products. The results have considerable implications for the use of Ga-doped Li7La3Zr2O12 electrolytes in all-solid-state Li-metal battery applications and raise the need for advanced materials engineering to realize Ga-doped Li7La3Zr2O12for practical use.},
  language  = {en}
}