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Published in Splinter Robert, Illustrated Encyclopedia of Applied and Engineering Physics, 2017
[electronics, mechanics, radiation, solid-state] Vacuum tube that has a cathode ray (i.e., electron beam) which is modulated in applied voltage, hence modulating the electron beam velocity profile. The electron beam thus creates density fluctuations and gradients. The klystron can act as a microwave amplifier or as an oscillator. During modulation the electron flow forms a wave pattern where fast electrons gain on slow electrons and overtake (dispersion), causing the electron density to fluctuate (see Figure K.41).
Oscillators and Signal Sources
Published in J. C. G. Lesurf, Millimetre-wave Optics, Devices and Systems, 2017
At around 100 GHz a typical reflex klystron can be expected to produce a continuous power level up to about 1 W and will require a beam voltage of 2–3 kV. The electronic tuning range of a reflex klystron is typically of the order of 100 MHz, and the mechanical tuning range will be then between 1 and 10 GHz. The operational life of a millimetre-wave klystron is usually a few hundred hours, although this may be extended by operating the tube at relatively low power levels.
Microwave Vacuum Devices
Published in Jerry C. Whitaker, The RF Transmission Systems Handbook, 2017
The klystron is one of the primary means of generating high power at UHF and above. Output powers for multicavity devices range from a few thousand watts to 10 MW or more. The klystron provides high gain and requires little external support circuitry. Mechanically, the klystron is relatively simple. It offers long life and requires minimal routine maintenance.
Co(II), Ni(II), and Cu(II) complexes derived from 1,2,4-triazine: synthesis, characterization, anticancer activity, DFT, and molecular docking studies with a COVID-19 protein receptor
Published in Journal of Coordination Chemistry, 2022
Fatma M. Elantabli, Mohamed R. Shehata, Abdelmoneim A. Makhlouf, Laila H. Abdel-Rahman
ESR is a useful tool for investigating the geometry of paramagnetic molecular systems. The ESR spectrum of the reported copper complex (Figure 3) was recorded at room temperature on the Klystron X-band at frequency 9.5 GHz, and with microwave power around 2.012 mW. The g factors were measured relative to the standard indicator 2,2-diphenyl-1-picrylhydrazyl (DPPH) (g=2.0037). The parallel and perpendicular ESR signals indicated distorted octahedron geometry [56, 57]. The value of g⊥ (2.225) is more than gǁ (2.091) which is more than 2.003, confirming the unpaired electron in the copper complex is localized in the dz2 orbital of the copper(II) ion [58, 59]. gǁ value is an evidence tool for covalent characteristics of the metal–ligand bond. For gǁ ˂ 2.3, the covalent state is the predominant state, while for the ionic case, it is generally = 2.3 [60]. Since the gǁ value of the copper complex is lower than 2.3, the Cu(II)-ligand bonds have a considerable covalent property. The geometric G factor can be considered as a measure of the exchange interaction between the copper centers in the solid compounds and is calculated with the expression [61]:
Design and development of FPGA-based real-time RF cavity simulator using LabVIEW
Published in International Journal of Electronics Letters, 2020
Sweta Khare, Nitesh Tiwari, Pritam Singh Bagduwal, Mahendra Lad
Indus-2 is the synchrotron radiation source facility running at Raja Ramanna Centre for Advanced Technology (RRCAT), Indore, India. It is a 2.5 GeV storage ring operating at the frequency of 505.812 MHz (Lad et al., 2007). Electrons of 550 MeV are injected to INDUS-2 by booster synchrotron, and then, these electrons are accelerated up to the energy level of 2–2.5 GeV. Four elliptical-shaped copper RF cavities are used, three of them are powered by solid-state amplifier and one is powered by Klystron 'Accelerate Activity'. The linearly varying voltage is provided to these cavities for generating a constant electric field inside it. But amplitude and phase of these cavities are not constant; it changes continuously due to high beam energy and current operation, so electric field inside cavities also varies continuously (Sharma et al., 2012; Schmüser).
A review of microwave testing of glass fibre-reinforced polymer composites
Published in Nondestructive Testing and Evaluation, 2019
Zhen Li, Arthur Haigh, Constantinos Soutis, Andrew Gibson, Ping Wang
A schematic diagram of the microwave thermography approach is illustrated in Figure 15. A horn antenna is used to direct the waves into the region of interest. A microwave source can be a magnetron, klystron, travelling wave tube or signal generator. Different signal excitation configurations (e.g. lock-in mode, pulsed mode, step mode or pulsed phase mode) can be adopted. An IR camera is located on the same side as the excitation source (reflection configuration). The antenna is placed at a distance from the sample that a sufficient field of view for the thermal camera can be provided. This distance affects the microwave illumination pattern (which in turn determines the effective inspection area) and strength at the surface. A personal computer is used for setting the measuring instruments, data acquisition and signal post-processing.