No abstract available

[en] The vertical field power supply system has been developed for HL-1M Tokamak. It includes 3 d. c. voltage sources. One of them is connected to the output side of 80 MVA generator. Another one connected from the 6 kV system. Its current waveform is controlled with computer program set or plasma position feedback set. The experiment shows that it is possible to obtain 4 s plasma duration on HL-1M Tokamak

[en] The configuration, program and algorithm for a horizontal plasma displacement feedback control system (FBCC) in the HL-2A tokamak are presented. The experiment results and the debugging of FBCC are also introduced. Compared with the previous discharges under the same discharge parameters, the FBCC effect is excellent. (authors)

[en] Based on an analysis of the wave propagation characteristics of an elliptic-groove waveguide, the use of this waveguide as a free electron laser (FEL) amplifier high frequency structure is proposed. A set of operating equations for this FEL amplifier is derived by using three-dimensional nonlinear theory. A numerical simulation code is developed, and the characteristics including the evolution of power, efficiency and bandwidth of the FEL amplifier are analysed numerically. The effects of electron energy spread and wiggler taper on the saturation efficiency are also considered

No abstract available

[en] The HL-2A control system consists of timing system, PLC logic control system and feedback control system. The timing system gives absolute time to all technical subsystems; the PLC logic control system provides synthetic logic conditions to the timing system and takes charge of personnel and machine protection; the feedback control system controls the plasma current, plasma position and plasma shape, which is essential to optimize plasma performance. The purpose and process of discharge management are introduced. The implementation of discharge management software is presented with emphasis on its dedicated data structures and its underlying software specifications. Software interface design principles are also discussed

[en] A free electron laser (FEL) amplifier with an elliptical waveguide and a planar wiggler is proposed. A set of coupled operating equations for this FEL operating in the Raman regime is derived using three-dimensional nonlinear theory. The numerical simulation code is developed, and the characteristics of this FEL amplifier are analysed numerically. Our numerical simulations are conducted to model a 34.6 GHz amplifier with an electron beam with an energy of 3.1 MeV. The results indicate that the elliptical waveguide is more suitable for a FEL with a planar wiggler system than a rectangular waveguide

[en] The compact free electron maser (FEM), with the advantages of small size and low cost, is important for realistic applications in medicine and industry. In order to utilize the planar wiggler to the best advantage and simultaneously to reduce the necessary electron beam voltage and the size of FEM device, we propose to utilize an elliptical waveguide as the high frequency structure of planar wiggler FEM. A set of universal operating equations suitable for elliptical waveguide and rectangular waveguide FEMs is derived by using the nonlinear theory. The characteristics of the FEMs are numerically analyzed, comparatively

[en] The use of an elliptical waveguide and a planar wiggler with parabolically tapered pole pieces as the terahertz free electron laser (FEL) amplifier model is proposed. A set of self-consistent differential equations for the FEL amplifier is derived by using nonlinear theory, and the characteristics of this amplifier are numerically analyzed. Our numerical simulations are conducted to the 1000 GHz amplifier with an electron beam energy of 1.74 MeV. The results indicate that the peak power of 180 kW and frequency bandwidth of 13.5 GHz can be obtained.

[en] A systematic stability analysis method using theoretical tools combining linear and self-consistent nonlinear theory is presented to analyze an ultrahigh gain gyrotron traveling-wave (gyro-TWT) amplifier operated in the fundamental TE₁₁ mode in the Ka-band. It characterizes the role that the backward-wave component plays in the internal feedback physical processes of two major kinds of self-induced oscillations associated with TE₁₁⁽¹⁾ absolute instability and TE₂₁⁽²⁾ gyrobackward-wave oscillation. For the first time, self-induced constriction in TE₁₁⁽¹⁾ absolute instability caused by a strong backward-wave component is revealed through simulation. Both the thickness and resistivity of the distributed wall loss loaded on the inside of the interaction waveguide have obvious effects on stabilizing both kinds of oscillations. Following the stability analysis, a multistage interaction circuit is proposed by nonlinear analysis which shortens the length of the entire structure and enables the ultrahigh gain gyro-TWT to operate with high stability and wide bandwidth.