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ISSN 2192-2764
Microwave-assisted alkaline hydrolysis of PET can be 20 times faster and at lower temperatures. This work presents a novel industrial microwave applicator at 2.45 GHz with homogeneous distribution to support this reaction, which allows an efficient and continuous operation. In addition, an innovative dielectric and calorimetric measurements setup is presented. Furthermore, the modelling of the reaction kinetics based on the measured dielectric parameters is presented.
Umfang: XXIV, 125 S.
Preis: 42.00 €
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This work presents the development of a new sub-THz source for the generation of trains of coherent high-power ultra-short pulses at 263 GHz via passive mode-locking of two coupled helical gyro-TWTs. For the first time, it is shown that the operation of such passive mode-locked helical gyro-TWTs in the hard excitation regime is of particular importance to reach the optimal coherency of the generated pulses. This could be of particular interest for some new time-domain DNP-NMR methods.
Umfang: XXV, 282 S.
Preis: 52.00 €
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Magnetic fusion is one approach to generate thermonuclear fusion power in an environmental friendly way. The Electron Cyclotron Resonance Heating is considered as the major concept for startup, heating and control of the fusion plasma. Megawatt-class gyrotrons generate the required microwave power. This work focuses on advanced key components and technologies for a DEMO relevant 2 MW gyrotron. One major focus is on the development of advanced Magnetron Injection Guns. Another focus is on the red.
Umfang: XV,160 S.
Preis: 45.00 €
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This work presents the design and testing of a new semiconductor-based pulsed power modulator meeting the challenging requirements of a pulsed electron beam device (GESA): a fast-rising (10^12 V/s) output voltage with arbitrary waveform of maximum 120 kV at a maximum current of 600 A for a pulse duration of up to 100 µs.
Umfang: XI, 170 S.
Preis: €44.00 | £40.00 | $77.00
Buchdetails
The multistage depressed collector (MDC) shall be one of the key technologies to achieve the required gyrotron efficiency in the DEMOnstration fusion power plant. For the first time, this work presents a comprehensive study of possible gyrotron MDC concepts. Concepts, only using axisymmetric E- and B-field components are shown to be insufficient. Instead, promising concepts using the E×B drift are proposed. A detailed study of a novel MDC concept using an azimuthal electric field is presented.
Umfang: XXI, 196 S.
Preis: €45.00 | £41.00 | $79.00
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The DEMOnstration fusion power plant (DEMO) will be the first fusion reactor, which is intended to generate net electrical power. For successful operation of DEMO, high-power gyrotrons with operating frequencies up to 240 GHz are required for plasma heating and stabilization. In this work, a systematic feasibility study and tolerance analysis are performed for the conventional-type hollow-cavity DEMO gyrotrons. The various approaches are also suggested to identify its operational limits.
Umfang: XIV, 241 S.
Preis: €48.00 | £44.00 | $84.00
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The physical design of cavity and magnetron injection gun (MIG) for a realistic, DEMO-compatible, coaxial-cavity 238 GHz 2 MW CW fusion gyrotron is developed in this work, having auxiliary frequencies at 170 GHz and 204 GHz. Novel systematic approaches towards multi-frequency mode selection, magnet requirements, and MIG design are presented. Mode deterioration and voltage depression variation due to insert misalignment versus cavity wall and/or versus electron beam are studied.
Umfang: XX, 236 S.
Preis: €46.00 | £42.00 | $81.00
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Gyrotrons are high-power mm-wave tubes. Here, the design, construction and experimental investigation of a 20 kW, 28 GHz gyrotron (2nd harmonic) are reported. This tube was designed to evaluate new emitters for future highly efficient and reliable fusion gyrotrons and for material processing applications. Following experimental results have been achieved in CW operation: 22.5 kW output power at 23.4 kV electron beam voltage and 2.23 A beam current with the world record efficiency of 43 %.
Umfang: XI, 132 S.
Preis: €42.00 | £39.00 | $74.00
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The increasing demand for powerful, reliable, and efficient gyrotron oscillators for Electron Cyclotron Resonance Heating (ECRH) in fusion plasma experiments requires a close look at the various factors in gyrotrons that determine gyrotron performance. In this frame, the influence of emitter surface roughness, emission inhomogeneity, and secondary electron generation on gyrotron operation is presented, with focus on Low Frequency Oscillations (LFOs) and Electron Beam Halo (EBH) generation.
Umfang: XV, 197 S.
Preis: €46.00 | £42.00 | $81.00
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In this work, an innovative real-time microwave control approach is proposed, to improve the temperature homogeneity under microwave heating. Multiple adaptive or intelligent control structures have been developed, including the model predictive control, neural network control and reinforcement learning control methods. Experimental results prove that these advanced control methods can effectively reduce the final temperature derivations and improve the temperature homogeneity.
Umfang: XIII, 231 S.
Preis: €46.00 | £42.00 | $81.00
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