Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

Recent research and development has been incredibly successful at advancing the capabilities for vacuum electronic device (VED) sources of powerful terahertz (THz) and near-THz coherent radiation, both CW or average and pulsed. Currently, the VED source portfolio covers over 12 orders of magnitude in power (mW-to-GW) and two orders of magnitude in frequency (from ; 10 THz). Further advances are still possible and anticipated. They will be enabled by improved understanding of fundamental beam-wave interactions, electromagnetic mode competition and mode control, along with research and development of new materials, fabrication methods, cathodes, electron beam alignment and focusing, magnet technologies, THz metrology and advanced, broadband output radiation coupling techniques.

Vacuum Electronic High Power Terahertz Sources

The electron cyclotron maser (ECM) is based on a stimulated cyclotron emission process involving energetic electrons in gyrational motion. It constitutes a cornerstone of relativistic electronics, a discipline that has emerged from our understanding and utilization of relativistic effects for the generation of coherent radiation from free electrons. Over a span of four decades, the ECM has undergone a remarkably successful evolution from basic research to device implementation while continuously being enriched by new physical insights. By delivering unprecedented power levels, ECM-based devices have occupied a unique position in the millimeter and submillimeter regions of the electromagnetic spectrum, and find use in numerous applications such as fusion plasma heating, advanced radars, industrial processing, materials characterization, particle acceleration, and tracking of space objects. This article presents a comprehensive review of the fundamental principles of the ECM and their embodiment in practical devices.

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The electron cyclotron maser

This article reviews the state-of-the-art in high-power microwave source research. It begins with a discussion of the concepts involved in coherent microwave generation. The main varieties of microwave tubes are classified into three groups, according to the fundamental radiation mechanism involved: Cherenkov, transition, or bremsstrahlung radiation. This is followed by a brief discussion of some of the technical fundamentals of high-power microwave sources, including power supplies and electron guns. Finally, the history and recent developments of both high-peak power and high-average power sources are reviewed in the context of four main areas of application: (1) plasma resonance heating and current drive; (2) rf acceleration of charged particles; (3) radar and communications systems; and (4) high-peak power sources for weapons-effect simulation and exploratory development.

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Review of high-power microwave source research

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Plasma Physics and Controlled Fusion Conference: Focussing on Tokamak Research

Research activity on development of gyrotron travelling-wave tubes (gyro-TWTs) at the Institute of Applied Physics of the Russian Academy of Sciences (IAP RAS) is presented. In the gyro-TWTs under discussion a helically corrugated waveguide is used as a principal part of their microwave circuits which ensures a number of advantages over other configurations of the gyro-TWTs.

Recent experiments and simulations on gyro-TWTs with helically corrugated waveguides

During last years several new gyrotrons were developed at IAP/GYCOM. Main efforts were spent for development 170GHz/1MW/50%/CW gyrotron for ITER and multi-frequency gyrotrons. The main ITER requirements to a gyrotron have been demonstrated: 1MW power, 1000 seconds pulse duration, 53% efficiency. The gyrotron operation regime of 1.2 MW was found for 100 second pulses. For a multi-frequency gyrotron a novel scheme for a tuneable window is discussed. Additionally some other new gyrotrons were shipped and installed at running plasma installations.

Recent results in development in Russia of megawatt power gyrotrons for fusion

A revised iter ec system baseline design proposal

A high power, tunable free electron maser for fusion

Development of the gyrotron system for ITER is based on solution of many very difficult scientific and engineering problems. At present the main purpose of the system modification is an enhancement of the system reliability and implementation of all gyrotron systems into ITER machine and its control and safety system. Recently development of ITER gyrotron system in Russia came into completion phase.

G. G. Denisov

Papers

Recent experiments and simulations on gyro-TWTs with helically corrugated waveguides

Recent results in development in Russia of megawatt power gyrotrons for fusion

A revised iter ec system baseline design proposal

A high power, tunable free electron maser for fusion

Completion phase of Russian gyrotron system development for ITER