Igor Girka was born in Kharkiv, Ukraine, in 1962. He received his M.S. degree in theoretical nuclear physics and his Candidate of Science and Doctor of Science degrees in plasma physics from V. N. Karazin Kharkiv National University (KKhNU), Kharkiv, in 1985, 1991, and 2004, respectively. In 2003-2005, he was a vice-president of the KKhNU. Since 2005, he has been a Dean of the School of Physics and Technology, KKhNU. He has authored 10 textbooks, 5 monographs, and 124 papers. His current research interests include propagation, conversion, and absorption of magneto hydrodynamic and surface-type electromagnetic waves in inhomogeneous plasma of fusion devices and devices of plasma electronics. Dr. Girka was awarded the prize of the National Academy of Sciences of Ukraine (NASU), named after K. D. Synelnykov in 2010. Since 2015, he has been a vice-president of Ukrainian Physical Society. In 2018, he was elected a corresponding member of NASU. He was awarded the honorary title "Honored Person of Science and Technology of Ukraine" by the Decree No.22 / 2020 of the President of Ukraine.Manfred Thumm was born in Magdeburg, Germany, in 1943. He earned his Dipl. Phys. and Dr. rer. nat. degrees in physics from the University of Tübingen, Germany, in 1972 and 1976, respectively. From 1976 to 1990, he joined the Institute for Plasma Research, University of Stuttgart, Germany. In June 1990, he became Professor at the Institute for Microwaves and Electronics of University of Karlsruhe, Germany, and Head of the Gyrotron Division, Institute for Technical Physics, Research Center Karlsruhe (later Karlsruhe Institute of Technology, KIT). From 1999 to 2011, he was Director of the Institute for Pulsed Power and Microwave Technology, KIT. M. Thumm has authored/co-authored 7 books, 21 book chapters, approx. 590 journal papers, and more than 1620 conference proceedings articles. He holds 14 patents on active and passive microwave devices. Since 2000, he has received 8 international awards. In 2002, he received the title of Honorary Doctor, presented by St. Petersburg State Technical University, Russia. In 2018, he became Fellow of VDE-ITG and in 2019 a Lifetime Fellow of IEEE. His research interests include high-power microwave engineering and plasma heating.

• Introduction.- Surface Flute Waves in Uniform Magneto-Active Plasma Filled Waveguides.- Electromagnetic Energy Rotation Caused by Surface Flute Waves.- Coupled Surface Flute Waves in Current-Carrying Plasma Waveguides.- Surface Flute Waves in Inhomogeneous Magnetized Plasma Waveguides.

Igor Girka was born in Kharkiv, Ukraine, in 1962. He received his M.S. degree in theoretical nuclear physics and his Candidate of Science and Doctor of Science degrees in plasma physics from V. N. Karazin Kharkiv National University (KKhNU), Kharkiv, in 1985, 1991, and 2004, respectively. In 2003-2005, he was a vice-president of the KKhNU. Since 2005, he has been a Dean of the School of Physics and Technology, KKhNU. He has authored 10 textbooks, 5 monographs, and 124 papers. His current research interests include propagation, conversion, and absorption of magneto hydrodynamic and surface-type electromagnetic waves in inhomogeneous plasma of fusion devices and devices of plasma electronics. Dr. Girka was awarded the prize of the National Academy of Sciences of Ukraine (NASU), named after K. D. Synelnykov in 2010. Since 2015, he has been a vice-president of Ukrainian Physical Society. In 2018, he was elected a corresponding member of NASU. He was awarded the honorary title "Honored Person of Science and Technology of Ukraine" by the Decree No.22 / 2020 of the President of Ukraine.Manfred Thumm was born in Magdeburg, Germany, in 1943. He earned his Dipl. Phys. and Dr. rer. nat. degrees in physics from the University of Tübingen, Germany, in 1972 and 1976, respectively. From 1976 to 1990, he joined the Institute for Plasma Research, University of Stuttgart, Germany. In June 1990, he became Professor at the Institute for Microwaves and Electronics of University of Karlsruhe, Germany, and Head of the Gyrotron Division, Institute for Technical Physics, Research Center Karlsruhe (later Karlsruhe Institute of Technology, KIT). From 1999 to 2011, he was Director of the Institute for Pulsed Power and Microwave Technology, KIT. M. Thumm has authored/co-authored 7 books, 21 book chapters, approx. 590 journal papers, and more than 1620 conference proceedings articles. He holds 14 patents on active and passive microwave devices. Since 2000, he has received 8 international awards. In 2002, he received the title of Honorary Doctor, presented by St. Petersburg State Technical University, Russia. In 2018, he became Fellow of VDE-ITG and in 2019 a Lifetime Fellow of IEEE. His research interests include high-power microwave engineering and plasma heating.

• Introduction.- Surface Flute Waves in Uniform Magneto-Active Plasma Filled Waveguides.- Electromagnetic Energy Rotation Caused by Surface Flute Waves.- Coupled Surface Flute Waves in Current-Carrying Plasma Waveguides.- Surface Flute Waves in Inhomogeneous Magnetized Plasma Waveguides.

Igor Girka was born in Kharkiv, Ukraine, in 1962. He received his M.S. degree in theoretical nuclear physics and his Candidate of Science and Doctor of Science degrees in plasma physics from V. N. Karazin Kharkiv National University (KKhNU), Kharkiv, in 1985, 1991, and 2004, respectively. In 2003-2005, he was a vice-president of the KKhNU. Since 2005, he has been a Dean of the School of Physics and Technology, KKhNU. He has authored 10 textbooks, 5 monographs, and 124 papers. His current research interests include propagation, conversion, and absorption of magneto hydrodynamic and surface-type electromagnetic waves in inhomogeneous plasma of fusion devices and devices of plasma electronics. Dr. Girka was awarded the prize of the National Academy of Sciences of Ukraine (NASU), named after K. D. Synelnykov in 2010. Since 2015, he has been a vice-president of Ukrainian Physical Society. In 2018, he was elected a corresponding member of NASU. He was awarded the honorary title "Honored Person of Science and Technology of Ukraine" by the Decree No.22 / 2020 of the President of Ukraine.Manfred Thumm was born in Magdeburg, Germany, in 1943. He earned his Dipl. Phys. and Dr. rer. nat. degrees in physics from the University of Tübingen, Germany, in 1972 and 1976, respectively. From 1976 to 1990, he joined the Institute for Plasma Research, University of Stuttgart, Germany. In June 1990, he became Professor at the Institute for Microwaves and Electronics of University of Karlsruhe, Germany, and Head of the Gyrotron Division, Institute for Technical Physics, Research Center Karlsruhe (later Karlsruhe Institute of Technology, KIT). From 1999 to 2011, he was Director of the Institute for Pulsed Power and Microwave Technology, KIT. M. Thumm has authored/co-authored 7 books, 21 book chapters, approx. 590 journal papers, and more than 1620 conference proceedings articles. He holds 14 patents on active and passive microwave devices. Since 2000, he has received 8 international awards. In 2002, he received the title of Honorary Doctor, presented by St. Petersburg State Technical University, Russia. In 2018, he became Fellow of VDE-ITG and in 2019 a Lifetime Fellow of IEEE. His research interests include high-power microwave engineering and plasma heating.

• Introduction.- Surface Flute Waves in Uniform Magneto-Active Plasma Filled Waveguides.- Electromagnetic Energy Rotation Caused by Surface Flute Waves.- Coupled Surface Flute Waves in Current-Carrying Plasma Waveguides.- Surface Flute Waves in Inhomogeneous Magnetized Plasma Waveguides.