The effects of electron-beam prebunching on the radiation buildup process in a free-electron maser oscillator operating in the frequency range of 4–5 GHz were studied. An electron beam of 10 keV, 1 A was prebunched by means of a microwave tube section, accelerated to 70 keV, transported through a drift region by a solenoidal magnetic field and injected into a linearly polarized wiggler in which...

In the large helical device (LHD), direct oblique launching of the extraordinary (X-) mode from the high magnetic field side is available without installation of any additional mirror or installation of a launcher in the inner side of the torus. The launched X-mode first encounters the electron cyclotron resonance (ECR) layer from the high magnetic field side and then approaches the upper hybri...

this article aims to review various modes of fracture toughness of resin composites. also, this study intends to review the papers on the fracture mode, namely “fractography”, under scanning electron microscopy finding fracture initiation site, and the effect of filler content on the fracture toughness of resin composites. it will also review the effect of aging on the fracture toughness of res...

The problem of excitation of the drift-tearing mode (Coppi, 1964) in high-temperature plasmas is considered. Existing theories predict that under the conditions typical of modern toroidal experiments on nuclear fusion, the mode is linearly stable in both collisionless (Coppi et al., 1979), and in a weakly collisional (Antonsen and Drake, 1983) regimes. We propose that the presence of a spectrum...

Detailed studies of the spectral characteristics and spatial mode structure of a single-mode, high power Raman Free-Electron Maser (FEM) oscillator operating with a Bragg resonator are reported. The FEM oscillator generated approximately 1 MW of microwave power in a single axial mode at 27.47 GHz, with an electron beam energy of 320 keV and a transmitted current of 30 A, yielding an efficiency ...